JP5073122B1 - AC electromagnet structure - Google Patents

Abstract

The AC electromagnet structure includes a disc-shaped movable member that is movable in the axial direction, an iron core yoke that is adjacent to the movable member in the axial direction via a main gap, and an annular first embedded in the iron core yoke. An excitation coil, an annular second excitation coil embedded in the iron core yoke outside the first excitation coil, and an annular kumatori coil embedded in the iron core yoke outside the second excitation coil. The Kumatori coil is disposed adjacent to the outer periphery of the second excitation coil and facing the main gap, and AC power is input to the first excitation coil and the second excitation coil, respectively. Is done.
[Selection] Figure 1

Description

  The present invention relates to an AC electromagnet structure.

  Conventionally, a concentric electromagnet structure is used by inputting DC power to an exciting coil.

  Patent Document 1 describes that in a motor with a brake that brakes a rotor when not driven, a coil fixed to a yoke is an inner / outer double coil in which currents flow in opposite directions. Thus, according to Patent Document 1, it is said that the magnetic flux reaching the inside of the rotating shaft is reduced when the motor is driven to rotate, and the influence of the magnetic field on the outside of the brake can be greatly reduced.

Japanese Utility Model Publication No. 6-74066

  In the motor with a brake described in Patent Document 1, it is considered that the inner and outer double coils function as concentric electromagnets around the rotation axis. Such concentric electromagnets are compatible only with DC power input, and are not compatible with AC power widely used in the industrial field. Therefore, it is necessary to prepare a direct current power source for use, and it is easy to increase the cost in using the electromagnet.

In the electromagnet described in Patent Document 1, when AC power is input to each excitation winding of the inner and outer double coils instead of DC power, the electromagnetic force fluctuates greatly from zero to the peak value, and the electromagnetic force is reduced. At the moment when it becomes zero, the armature is pressed against the fixed plate by the biasing force of the spring. As a result, the rotor is braked even when the motor is being driven, so that it tends to be unusable in practical use. That is, with the electromagnet described in Patent Document 1, it is difficult to reduce the cost in using the electromagnet.
This invention is made | formed in view of the above, Comprising: It aims at obtaining the alternating current electromagnet structure which can reduce the cost in utilization of an electromagnet.

  In order to solve the above-described problems and achieve the object, an AC electromagnet structure according to one aspect of the present invention includes a disc-shaped movable member that is movable in an axial direction, and a main gap with respect to the movable member. An axially adjacent iron yoke, an annular first exciting coil embedded in the iron core yoke, and an annular second exciting coil embedded in the iron core yoke outside the first exciting coil; An annular Kumatori coil embedded in the iron core yoke outside the second excitation coil, and the Kumatori coil is disposed adjacent to the outer periphery of the second excitation coil and facing the main gap. AC power is input to each of the first excitation coil and the second excitation coil.

  According to the present invention, pulsation of electromagnetic force by the first excitation coil and the second excitation coil can be effectively suppressed, and the movable member can be continuously driven. Therefore, it is not necessary to prepare a separate DC power source for use, and the cost for using the electromagnet can be reduced.

FIG. 1 is a cross-sectional view illustrating a configuration of an AC electromagnet structure according to the first embodiment. FIG. 2 is a perspective cross-sectional view illustrating a configuration of the AC electromagnet structure according to the first embodiment. FIG. 3 is a magnetic flux diagram showing the operation of the AC electromagnet structure according to the first exemplary embodiment. FIG. 4 is an electromagnetic force waveform diagram showing the effect of the first embodiment. FIG. 5 is a cross-sectional view illustrating a configuration of an AC electromagnet structure according to the second embodiment. FIG. 6 is a diagram illustrating a comparative example.

  Embodiments of an AC electromagnet structure according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
An AC electromagnet structure 100 according to a first exemplary embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing a configuration of an AC electromagnet structure 100. FIG. 2 is a perspective sectional view showing the configuration of the AC electromagnet structure 100.

  The AC electromagnet structure 100 receives AC power, generates an electromagnetic force acting on the movable member 102, and operates the movable member 2 in the direction along the axis AX. For example, the AC electromagnet structure 100 applies a magnetic attractive force to the movable member 102 to bring the movable member 102 closer to the yoke 150 side along the axis AX. Specifically, the AC electromagnet structure 100 includes a movable member 102 and a yoke 150.

  The movable member 102 is configured to be movable in a direction along the axis AX. The movable member 102 is a disk-shaped member. The movable member 102 is formed using, for example, a dust core. Thereby, the heat_generation | fever of the movable member 102 by an eddy current loss can be reduced.

  The yoke 150 receives AC power and generates an electromagnetic force that acts on the movable member 102. The yoke 150 includes an iron core yoke 140, a first excitation coil 110, a second excitation coil 120, and a Kumatori coil 130.

  The iron core yoke 140 is adjacent to the movable member 102 in the direction along the axis AX via the main gap 3. That is, the iron core yoke 140 faces the movable member 102 with the main gap 3 interposed therebetween. The iron core yoke 140 has, for example, a substantially cylindrical shape corresponding to the movable member 102. The iron core yoke 140 is formed using, for example, a dust iron core. Thereby, heat_generation | fever of the iron core yoke 140 by an eddy current loss can be reduced.

  The iron core yoke 140 has a gap 104 for preventing residual magnetism between the first exciting coil 110 and the second exciting coil 120. That is, the facing surface 140b between the first exciting coil 110 and the second exciting coil 120 in the iron core yoke 140 is further away from the movable member 102 than the outer facing surface 140a, and the inner facing surface 140c. Rather than the movable member 102. As a result, a gap 104 for preventing residual magnetism is formed between the first exciting coil 110 and the second exciting coil 120 in the iron core yoke 140.

  The first excitation coil 110 is embedded in the iron core yoke 140 inside the second excitation coil 120 and inside the kumatori coil 130. The first exciting coil 110 extends in an annular shape so as to surround the axis AX. The first exciting coil 110 has, for example, a substantially cylindrical shape centered on the axis AX. The first excitation coil 110 is formed of, for example, a winding of a conductor (for example, a metal or an intermetallic compound containing aluminum or copper as a main component). The first exciting coil 110 faces the main gap 3 on the movable member 102 side.

  The second excitation coil 120 is embedded in the iron core yoke 140 on the outside of the first excitation coil 110 and on the inside of the Kumatori coil 130. The second exciting coil 120 extends in an annular shape so as to surround the axis AX. The second exciting coil 120 has, for example, a substantially cylindrical shape centered on the axis AX. The second exciting coil 120 is formed of, for example, a conductor (for example, a metal or an intermetallic compound mainly composed of aluminum or copper). The second exciting coil 120 faces the main gap 3 on the movable member 102 side.

  That is, the first exciting coil 110 and the second exciting coil 120 form a concentric shape with the axis AX as a common center. For example, the second excitation coil 120 extends so as to surround the first excitation coil 110 while maintaining a substantially constant interval with respect to the first excitation coil 110. At this time, the ampere-turn number of the winding of the second exciting coil 120 is larger than the ampere-turn number of the winding of the first exciting coil 110. For example, the winding of the first excitation coil 110 and the winding of the second excitation coil 120 are connected in series or in parallel.

  The Kumatori coil 130 is embedded in the iron core yoke 140 outside the first excitation coil 110 and outside the second excitation coil 120. The Kumatori coil 130 extends in an annular shape so as to surround the axis AX. The Kumatori coil 130 has, for example, a substantially ring shape centered on the axis AX. The second exciting coil 120 is formed of, for example, a conductor (for example, a metal or an intermetallic compound containing aluminum or copper as a main component). The Kumatori coil 130 is adjacent to the outer periphery of the second excitation coil 120 via the layer 160. The Kumatori coil 130 is disposed at a position facing the main gap 3. The part of the movable coil 102 facing the main coil 130 faces the main gap 3.

The layer 160 is sandwiched between the second excitation coil 120 and the Kumatori coil 130 and electrically and magnetically insulates the second excitation coil 120 and the Kumatori coil 130 from each other. The layer 160 includes, for example, at least one of an air layer and a nonmagnetic material layer.
Next, the operation of the AC electromagnet structure 100 will be described with reference to FIG. FIG. 3 is a magnetic flux diagram showing the operation of the AC electromagnet structure 100.

  In the AC electromagnet structure 100, AC power is input to the first excitation coil 110 and the second excitation coil 120, respectively. Specifically, in the first excitation coil 110 and the second excitation coil 120, the direction of current flow in the first excitation coil 110 and the direction of current flow in the second excitation coil 120 are opposite to each other. AC power is input respectively. For example, the first excitation coil 110 and the second excitation coil 110 are controlled so that the difference between the phase of the current vector flowing in the first excitation coil 110 and the phase of the current vector flowing in the second excitation coil 120 is 180 degrees. AC power is input to each of the excitation coils 120.

  Then, as shown in FIG. 3, the winding of the first exciting coil 110 generates a magnetic flux flow 5 indicated by a broken line, and the winding of the second exciting coil 120 generates a magnetic flux flow 6 indicated by a broken line. Generate. Since AC power is supplied to the first exciting coil 110 and the second exciting coil 120, the magnitude and direction of the magnetic flux flow 5 and the magnetic flux flow 6 dynamically change. At this time, since the ampere-turn number of the winding of the second exciting coil 120 is larger than the ampere-turn number of the winding of the first exciting coil 110, the magnetic flux and the second excitation by the first exciting coil 110 are increased. The combined magnetic flux with the magnetic flux by the coil 120 can be easily linked to the Kumatori coil 130.

  As a result, an electromotive force that cancels fluctuations in the magnitude and direction of the magnetic flux flow 5 and the magnetic flux flow 6 can be induced in the Kumatori coil 130, and an induced current can be caused to flow in the Kumatori coil 130. The magnetic flux flow 7 shown can be generated. That is, since the magnetic flux generated by the Kumatori coil 130 does not pass through the gap 104 for preventing residual magnetism, the magnetomotive force loss caused by the gap 104 for preventing residual magnetism can be reduced, and the magnetic flux generated by the Kumatori coil 130 can be used effectively. In other words, as indicated by a solid line in FIG. 4, pulsation of electromagnetic force by the first exciting coil 110 and the second exciting coil 120 can be effectively suppressed by the magnetic flux by the Kumatori coil 130. Note that FIG. 4 shows the results of simulation of electromagnetic force for each of the cases where there is a bear coil (indicated by a solid line) and in the absence (indicated by a broken line). From this, the effectiveness of pulsation reduction of electromagnetic force by Kumatori coil was confirmed.

  Here, suppose that the AC electromagnet structure 1 does not have the Kumatori coil 130 (see FIG. 1) as shown in FIG. In this case, in the yoke 50, the pulsation of the electromagnetic force due to the first exciting coil 10 and the second exciting coil 20 embedded in the iron core yoke 40 is remarkably generated. In the AC electromagnet structure 1, when AC power is input to the respective windings of the first excitation coil 10 and the second excitation coil 20, the first excitation coil 10 and the second excitation coil 10 are shown in FIG. Since the electromagnetic force by the exciting coil 20 fluctuates greatly from zero to the peak value, and the magnetic attractive force cannot be applied to the movable member 2 at the moment when the electromagnetic force becomes zero, the movable member 2 is primarily moved. Since it cannot be driven, it tends to be unusable in practical use. Therefore, it is necessary to prepare a separate DC power source for use and to input DC power to the respective windings of the first exciting coil 10 and the second exciting coil 20, which easily increases the cost of using the electromagnet. .

  On the other hand, in the first embodiment, AC electromagnet structure 100 has a Kumatori coil 130. The Kumatori coil 130 is disposed adjacent to the outer periphery of the second exciting coil 120 and facing the main gap 3. As a result, when AC power is input to the first excitation coil 110 and the second excitation coil 120, the Kumatori coil 130 causes the magnitude of the magnetic flux generated by the first excitation coil 110 and the magnitude of the magnetic flux generated by the second excitation coil 120, respectively. It is possible to generate a magnetic flux that cancels the variation in height and direction. As a result, as shown by a solid line in FIG. 4, pulsation of electromagnetic force by the first exciting coil 110 and the second exciting coil 120 can be effectively suppressed by the magnetic flux by the Kumatori coil 130, and the movable member 2 can be continuously moved. Can continue to drive. Therefore, it is not necessary to prepare a separate DC power source for use, and the cost for using the electromagnet can be reduced. As a result, for example, an AC electromagnet that is inexpensive, excellent in size, performance, and quality can be provided.

  Alternatively, if the AC electromagnet structure 1 has the Kumatori coil 130 (see FIG. 1), the number of ampere turns of the winding of the first exciting coil 10 and the number of ampere turns of the winding of the second exciting coil 20 will be described. Are considered to be equal to each other (see FIG. 6). In this case, since the magnitude of the magnetic flux generated by the second exciting coil 20 is larger than the magnitude of the magnetic flux generated by the first exciting coil 10, the magnetic flux generated by the first exciting coil 10 and the magnetic flux generated by the second exciting coil 20 are combined. It is difficult for the generated magnetic flux to interlink with the Kumatori coil 130.

  Alternatively, if the AC electromagnet structure 1 has the Kumatori coil 130 (see FIG. 1), the number of ampere turns of the winding of the first exciting coil 10 is the number of ampere turns of the winding of the second exciting coil 20. Think about the larger case. In this case, since the magnitude of the magnetic flux generated by the second exciting coil 20 is relatively larger than the magnitude of the magnetic flux generated by the first exciting coil 10, the magnetic flux generated by the first exciting coil 10 and the second exciting coil 20 are increased. The magnetic flux combined with the magnetic flux generated by the magnetic flux becomes more difficult to interlink with the Kumatori coil 130.

  On the other hand, in the first embodiment, the number of ampere turns of the winding of the second exciting coil 120 is larger than the number of ampere turns of the winding of the first exciting coil 110. In addition, the first excitation coil 110 and the second excitation coil 120 have an alternating current so that the direction of current flow in the first excitation coil 110 and the direction of current flow in the second excitation coil 120 are opposite to each other. Each power is input. As a result, the combined magnetic flux of the magnetic flux generated by the first exciting coil 110 and the magnetic flux generated by the second exciting coil 120 can be easily linked to the Kumatori coil 130. As a result, an electromotive force that cancels fluctuations in the magnitude and direction of the magnetic flux flow 5 and the magnetic flux flow 6 can be induced in the Kumatori coil 130, and an induced current can be caused to flow in the Kumatori coil 130. In addition, the magnetic flux flow 7 can be generated so as to cancel the variation in the magnitude and direction of the magnetic flux flow 6. That is, the pulsation of electromagnetic force by the first excitation coil 110 and the second excitation coil 120 can be effectively suppressed.

  In the first embodiment, the second exciting coil 120 and the Kumatori coil 130 are adjacent to each other via at least one of the air layer and the non-magnetic material layer, and are electrically and magnetically insulated from each other. Yes. As a result, the combined magnetic flux of the magnetic flux generated by the first exciting coil 110 and the magnetic flux generated by the second exciting coil 120 can be made difficult to pass between the second exciting coil 120 and the Kumatori coil 130, and the first exciting coil The combined magnetic flux of the magnetic flux generated by the coil 110 and the magnetic flux generated by the second exciting coil 120 can be effectively linked to the Kumatori coil 130 (for example, without leakage).

  In the first embodiment, the iron core yoke 140 has a gap 104 for preventing residual magnetism between the first exciting coil 110 and the second exciting coil 120. Thereby, the electromagnet opening failure due to the residual magnetism of the iron core yoke 140 can be suppressed. On the other hand, since the magnetic flux generated by the Kumatori coil 130 is difficult to pass through the gap 104 for preventing residual magnetism (see FIG. 3), the magnetic flux generated by the Kumatori coil 130 can be used effectively. That is, the opening failure of the electromagnet due to the residual magnetism of the iron core yoke 140 can be suppressed, and the pulsation of the electromagnetic force by the first exciting coil 110 and the second exciting coil 120 can be effectively suppressed.

  Note that the surface of the first exciting coil 110 facing the main gap 3, the portion of the second exciting coil 120 facing the main gap 3, and the portion of the Kumatori coil 130 facing the main gap 3 each have an epoxy surface. It may be enclosed with a non-magnetic material such as a material. As a result, a portion facing the main gap 3 in the first exciting coil 110, a portion facing the main gap 3 in the second exciting coil 120, and a portion facing the main gap 3 in the Kumatori coil 130 are oxidized, respectively. Can be protected from.

Embodiment 2. FIG.
Next, the AC electromagnet structure 200 according to Embodiment 2 will be described. Below, it demonstrates focusing on a different part from Embodiment 1. FIG.

  In the AC electromagnet structure 200, each of the movable member 202 and the yoke 250 has a hollow structure. Specifically, the movable member 202 has an opening 202d centered on the axis AX. The iron core yoke 240 of the yoke 250 has a through hole 240d centered on the axis AX. The opening 202 d of the movable member 202 corresponds to the through hole 240 d of the iron core yoke 240. Accordingly, the rotating shaft of the rotating device can be configured to pass through the opening 202d and the through-hole 240d so that the movable member 202 rotates together with the rotating shaft, and the AC electromagnet structure 200 can be used as an electromagnetic brake for braking the rotating device. it can.

  As described above, the AC electromagnet structure according to the present invention is useful for an electromagnetic brake.

1, 100, 200 AC electromagnet structure 2, 102, 202 Movable member 3 Main gap 10, 110 First excitation coil 20, 120 Second excitation coil 40, 140, 240 Iron yoke 50, 150, 250 Yoke 104 Residual magnetism Gap for prevention 130 Kumatori coil 160 layers

Claims (4)

A disc-shaped movable member movable in the axial direction;
An iron core yoke axially adjacent to the movable member via a main gap;
An annular first exciting coil embedded in the iron core yoke;
An annular second exciting coil embedded in the iron core yoke outside the first exciting coil;
An annular Kumatori coil embedded in the iron core yoke outside the second exciting coil;
With
The Kumatori coil is disposed at a position adjacent to the outer periphery of the second excitation coil and facing the main gap,
AC power is input to the first exciting coil and the second exciting coil, respectively. An AC electromagnet structure. The number of ampere turns of the winding of the second exciting coil is larger than the number of ampere turns of the winding of the first exciting coil,
The first exciting coil and the second exciting coil have AC power so that the direction of current flow in the first exciting coil and the direction of current flowing in the second exciting coil are opposite to each other. The AC electromagnet structure according to claim 1, wherein each is input. The second excitation coil and the Kumatori coil are adjacent to each other via at least one of an air layer and a non-magnetic material layer, and are electrically and magnetically insulated from each other. 1. The AC electromagnet structure according to 1. 2. The AC electromagnet structure according to claim 1, wherein the iron core yoke has a gap for preventing residual magnetism between the first exciting coil and the second exciting coil.

Images