JPH01298937A - Stator for dc electric machine - Google Patents

Abstract

PURPOSE:To prevent a spark from generating from a brush at the time of transient operation by providing a magnetic flux change suppressing member partly at least at a leakage interpole magnetic flux flowing passage via a short- circuiting core. CONSTITUTION:Short-circuiting cores 10A, 10B made of laminated iron plates are provided on the side face of an interposed core 8 near an armature 6, and lumped cores 11A, 11B are provided on the side faces of the cores 10A, 10B at the main pole core 4 side. The cores 11A, 11B so generates eddy currents as to suppress the change of a leakage interpole magnetic flux against the abrupt change of a load current. Thus, the interpole magnetic flux for obtaining a preferable rectifying state at the time of abrupt load current change can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a DC machine, and more particularly to a stator of a DC machine suitable for compensating for the phenomenon of no-spark zone movement with respect to rotational speed.

[Prior art] Direct current machines have long had the phenomenon of movement of the non-sparking band, in which the position of the non-sparking band moves toward the excitation side as the rotational speed increases.As a countermeasure for this, (1) compensation for the rotational speed has been proposed. A method of adjusting the pole shunt current, and (2) a method of adjusting the interpolation magnetic flux using a separate power source are used. However, these methods involve adding equipment in addition to the DC machine itself, so they are expensive. Therefore, as a countermeasure using only the DC machine itself, we proposed
There is a publication No. 3, in which a DC machine shown in FIGS. 4 to 7 is proposed.

Fig. 4 shows an exploded view of the main parts of the DC machine.
and is provided. Main pole 2 has main pole iron core 4 and magnetic pole piece 4A
and field winding 5, and serves to provide main magnetic flux to the armature winding 7 of the armature 6 rotating inside the stator, and the commutator 3 has a commutator core 8 and a commutator winding 9. It serves to provide a commutating magnetic flux for generating a rectified electromotive force during a rectification phenomenon in which the current flowing through the armature winding 7 is reversed.

Moreover, between the main pole 2 and the commutator pole 3, ff11 of the commutator iron core 8 is provided.
A short-circuit core 10 (IOA, 10B) is provided to short-circuit the side surface near the child 6 side and the side surface of the magnetic pole piece 4A.

The operation of this configuration at low speed and high speed operation is shown in FIG. Figure (a) shows when driving at low speed.
(b) shows high-speed operation, φMP (φMP
I, φMP2) is the main magnetic flux, φ1. (φ03.～φIP
) is the commutating magnetic flux, and φIA (φIA1+φ, A,) is the commutating magnetic flux for rectification compensation. During low-speed operation in the same figure (a), the main magnetic flux φMF□ becomes large due to the strong field, and the magnetic flux density between the main pole iron core 4 and the yoke 1 becomes high, resulting in a magnetically saturated state, and the short-circuited iron core The leakage interpolation magnetic flux leaking through 10B is only φ1,1, and the remaining φIPzw φ! ?
, are rectification compensation commutating magnetic fluxes φ, A□ which are incident on the armature 6 side to generate a rectification electromotive force.

During high-speed operation in the figure (b), the field is weakened, so the main magnetic flux φMP□ is small, and the magnetic flux density between the main pole iron 4 and the yoke 1 is low, resulting in a short circuit because it is not magnetically saturated. The commutating magnetic flux φIP easily leaks to the main pole iron core 4 via the iron core 10B, the commutating magnetic flux φIPx+z becomes the leaking commutating flux to the main pole iron core 4, and φIP3 enters the armature 6 and becomes a commutating pole for commutation compensation. The magnetic flux becomes φ1A□. In this manner, the amount of magnetic flux incident on the armature 6 is smaller during high-speed operation than during low-speed operation, so the phenomenon of movement of the non-spark zone can be prevented.

[Problem to be solved by the invention] The above-mentioned conventional technology does not take into consideration the issue during transient operation, and when applied to a DC machine operated in four quadrants, there is a problem that sparks are generated from the brush when the load current suddenly changes. It has been found.

An object of the present invention is to solve the problems of the prior art described above, and to fix a DC machine that can prevent the phenomenon of no-spark band movement using only the main body of the DC machine, and also prevent the generation of sparks from the brushes under any operating conditions. It is to provide a child.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes an armature of a rotor and a stator disposed opposite to the rotor, the stator having an annular joint. iron, a plurality of main poles attached to the inner peripheral side of this yoke and consisting of a main pole iron core and a field winding, and a plurality of main poles attached to the yoke between these main poles and consisting of a commutating pole iron core and a commutating pole winding; In a DC machine, a short-circuiting iron core is provided between the main pole iron core and the auxiliary iron core to short-circuit the armature sides of both of them and to allow leakage commutator magnetic flux to flow. , characterized in that a block core portion is provided in at least a portion of the flow path of the leakage interpolation magnetic flux passing through the short-circuit core.

[Function] The block core portion provided in the flow path of the leakage polarization magnetic flux via the short-circuited core generates an eddy current so as to suppress a change in the leakage polarization flux in response to a sudden change in the load current. Thereby, it is possible to secure interpolation magnetic flux for obtaining a good rectification state when the load current suddenly changes, and thereby it is possible to prevent sparks from occurring from the brush.

[Example] Prior to a detailed explanation of the present invention, the results of the investigation by the present inventors regarding the reason why sparks are generated from the brush in a conventional device when the load current suddenly changes are shown in FIGS. This will be briefly explained using c) and FIG.

Figures 6(a) to 6(c) show exploded views of the main parts of the DC machine when the load current suddenly changes. In the same figure (a), time is plotted on the horizontal axis, and change in load current is plotted on the vertical axis. In a DC machine operated at a limit of 4 gA, the load current rapidly increases, reaches a steady state, and then rapidly decreases (current changes in the negative direction are not shown). Figure (b) shows the operation during low-speed operation when the load current suddenly increases. During low-speed operation shown in the figure, the main magnetic flux φMp1 becomes large due to the strong field, and the interpolation magnetic flux φ1. As in the past, the φRP work connects the main pole core 4 through the short-circuit core 10B.
leakage to the magnetic flux, resulting in leakage commutating magnetic flux. Figure (c) shows the armature reaction magnetomotive force, which is maximum at the center of the commutating poles. Therefore, in the same figure (b), the commutating magnetic flux φTP3 at the time of sudden increase in load current is determined by the fact that the commutating pole air gap length is larger than the main pole air gap length and the armature reaction magnetomotive force is maximum at the center of the commutating pole. , leaks to the main pole iron core 4 through the short-circuited iron core 10A, and becomes a leakage interpolation magnetic flux. As a result, the commutating magnetic flux that is incident on the armature 6 side to generate a rectified electromotive force becomes only φTPz, and the commutating compensating commutating magnetic flux φfA1 becomes small.

In Figure 7, the horizontal axis shows the load current, and the vertical axis shows the commutating pole magnetic flux φ, A for commutation compensation. Polar magnetic flux decreases. The same holds true when the load current suddenly decreases and during high-speed operation.

From this, it has been found that during transient operation, leakage commutating magnetic flux increases in response to changes in load current, commutating improving commutating flux decreases, and a problem occurs in which sparks are generated from the brush.

The present invention will now be explained based on the embodiments shown in FIGS. 1(A) to 3. FIG. FIGS. 1A and 1B show an exploded view of the main parts of a DC machine and a partial perspective view of a short-circuit core according to an embodiment of the present invention. In each figure, parts that are the same as or equivalent to those in the prior art are designated by the same reference numerals, and explanations thereof will be omitted. In each cycle, a short-circuit core 10 (IOA) made of laminated iron plates is placed near the armature 6 side of the commutating pole core 8.

10B) on one side of the block iron core 11 (IIA).

11B) is provided. As shown in the same figure (b),
When the leakage interpolation magnetic flux φIPI tries to change in the direction of the arrow, the block iron core 11B generates an eddy current i in the direction to suppress it.
. occurs.

In such a configuration, when the load current increases rapidly as shown in FIG. 2(A), the main pole magnetic flux φ0. Commutating magnetic flux φ! P is the same figure (
During low-speed operation (b), it operates as in high-speed operation shown in (c) of the same figure. During low-speed operation as shown in Figure (b), the main magnetic flux φ0. becomes large, and the magnetic flux density between the main pole iron core 4 and the yoke l becomes high, resulting in a magnetically saturated state. Then, as a result of suppressing the rapid increase in the leakage commutator magnetic flux by the block core 11, the leakage commutator flux leaking through the short-circuit core 10B becomes only φ and □, and the remaining magnetic flux φrPte φII
P3 is a commutating magnetic flux φ0 for commutation compensation which is incident on the armature 6 side to generate a rectified electromotive force.

During high-speed operation in the figure (c), since the field is weakened, the main magnetic flux φMPz becomes small, and the magnetic flux density between the main pole iron core 4 and the yoke 1 is low, resulting in a state in which (Ia is not magnetically saturated). As a result of suppressing the sudden increase in the leakage commutator magnetic flux by the block iron core 11, the leakage commutator flux leaking through the short-circuit core 10B becomes φ□P1+φIP2.

The remaining magnetic flux φIP3 enters the armature 6 side and becomes a commutating pole magnetic flux φiAz for commutation compensation.

In this way, the amount of magnetic flux incident on the armature 6 side is smaller during high-speed operation than during low-speed operation, so the movement of the non-spark zone can be prevented only by the DC machine main body. In FIG. 3, the horizontal axis shows the load current, and the vertical axis shows the commutating magnetic flux φ, A for commutation compensation during steady operation and transient operation. As is clear from the figure, since the commutating magnetic flux for rectification compensation during transient operation where the load current suddenly changes can be obtained almost the same as during steady operation, there is an effect of preventing the generation of sparks from the brush during transient operation.

In addition, in the description of the above embodiment, an example was explained in which the block core 11 was configured as a part of the short-circuit core 10, but the short-circuit core itself may be configured with a block core, or the lamination thereof may be short-circuited to a part of the short-circuit core. A similar effect can be obtained by providing a short circuit layer.

[Effects of the Invention] As described above, in the present invention, since the block iron core is provided in at least a part of the flow path of the leakage commutator magnetic flux, changes in the leakage commutator flux are suppressed in response to sudden changes in the load current. It is possible to secure the necessary commutating magnetic flux for commutation compensation, thereby making it possible to prevent sparks from occurring from the brush during transient operation.

[Brief explanation of the drawing]

Figures 1 (A) and (B) are an exploded view of the main parts and a perspective view of a short-circuit core of a DC machine according to an embodiment of the present invention, Figure 2 (A) is a characteristic diagram of load current, and Figure 2 ( (b) and (c) are exploded views of the main parts of the DC machine, respectively, to explain the operation of the configuration shown in Fig. 1 (a) during low-speed operation and high-speed operation, and Fig. 3 is the exploded view of the main parts of the DC machine shown in Fig. 1 (
A graph showing the relationship between load current and interpolation magnetic flux in the configuration shown in A), Fig. 4 is an exploded view of the main parts of a conventional DC machine, and Figs. 5 (A) and (B) each show the configuration shown in Fig. 4. Figure 6 (a) is an exploded view of the main parts of a DC machine explaining the operation during low-speed and high-speed operation, and Figure 6 (a) is a characteristic diagram of load current during operation.
Figure 6 (B) is an exploded view of the main parts of the DC machine that explains the operation of the configuration shown in Figure 4 when the load current suddenly changes, and Figure 6 (C)
is the characteristic diagram of armature reaction magnetomotive force. FIG. 7 is a graph showing the conventional relationship between load current and interpolation magnetic flux. 1...Yoke, 2...Main pole, 3...
...Commuting pole, 4...Main pole iron core, 5...
Field winding, 6...Armature, 7...Armature winding, 8...Commuting pole iron core, 9...Commuting pole winding, 1o: short-circuited core, 11: lumpy core. Figure 1 Figure 2 Figure 3 Figure 5 (A) Figure 6 (1') Figure 7

Claims (1)

[Scope of Claims] 1. A rotor armature and a stator disposed opposite to the rotor, the stator comprising a ring-shaped yoke, attached to the inner circumferential side of the yoke, and A plurality of main poles consisting of a main pole iron core and a field winding, a plurality of commutating poles attached to the yoke between these main poles and consisting of a commutating pole iron core and a commutating pole winding, the main pole iron core In a DC machine, a short-circuit core is provided between the armature side of the armature and the leakage commutator magnetic flux, and the leakage commutator flux passes through the short-circuit core. A stator for a DC machine, characterized in that a block iron core is provided in at least a part of a flow passage. 2. The stator for a DC machine as set forth in claim 1, wherein the short-circuit core is composed of a block core. 3. The stator for a DC machine according to claim 1, wherein the massive iron core is provided on a side surface of the main pole iron core. 4. The stator for a DC machine as set forth in claim 1, wherein the lumpy core is provided on a side surface of the commutating pole core. 5. The stator of a DC machine according to claim 1, wherein the block iron core is constructed by short-circuiting end faces of a laminated iron core that constitutes the short-circuit iron core.