JPS5928137B2 - DC rotating electric machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a DC rotating electrical machine, and particularly to a DC rotating electrical machine having a circular, iron-free rotor.

A DC rotating electric machine using a coreless rotor to improve high-speed response characteristics is known.

Such a DC rotating electric machine has, for example, a very thin cup-shaped winding, one end of which is fixed to a shaft, and a permanent magnet field fixed inside the cup-shaped rotor.

However, since the volume of the rotor winding is extremely small,
Due to restrictions on the amount of winding, it was limited to those with a low torque factor and relatively small size.

Cup-shaped rotors with relatively thick rotor windings have also been adopted, but this increases the amount of windings, resulting in a decrease in torque-to-inertia ratio.

Furthermore, since it has a cantilevered structure in which only one end of the rotor winding is fixed to the shaft, it has the disadvantage of low surf strength.

In addition, as a high-speed response DC motor, a rotor with a winding wound around the outer surface of a smooth iron core or a winding made by printed wiring technology is used, but when the magnetic flux density in the air gap is large, the rotor There is a drawback that the iron loss of the iron core is large and the efficiency is reduced, and there is also a problem in manufacturing technology for fixing the rotor winding thinly for use outside the smooth iron core.

Furthermore, in order to obtain high-speed response, it was necessary to tolerate a high temperature rise in the winding.

The present invention is a novel invention that improves the conventional drawbacks as described above, and its purpose is to provide a highly efficient and fast-responsive DC rotating electric machine.

Leprosy cases will be explained in detail below.

FIG. 1 shows a schematic cross-sectional view of an example of the present invention.
The rotor 1 has a rotor winding 1a provided on a rotating shaft 2 made of a non-magnetic material such as stainless steel through an insulator, and constitutes a completely ironless rotor.

It goes without saying that the rotating shaft 2 can be made of ordinary magnetic steel.

In addition, as the field magnet, a ferrite or other rectangular permanent magnet 5 with a large coercive force is used, and the ferrite magnet has a magnetic permeability of 1.
．． 1 and in space, the pair of magnetic pole pieces 3 are connected to a substrate 4 made of a ferromagnetic material for converging the magnetic flux of the permanent magnet 5.
It is attached to the outside of the rounded coreless rotor 1 to form a two-pole field.

The yoke 7 that forms part of the magnetic path of such a field magnet configuration
As shown in the figure, there is provided a magnetic flux controlling magnetic body 6 formed by laminating thin plates in a direction perpendicular to the magnetic path.

This magnetic flux control magnetic material 6 is made of a magnetic material such as 45% Ni permalloy, which exhibits saturation characteristics at a magnetization force greater than or equal to the magnetizing force.

When thin plate-like magnetic materials are stacked in the magnetic path direction, the accumulation of minute air layers between the layers exhibits magnetoresistance, making it impossible to obtain the magnetic properties of true magnetic materials.

Since the above-mentioned magnetic flux controlling magnetic material is laminated in a direction perpendicular to the magnetic path, the magnetic flux passes directly through each thin plate without passing through an interlayer air layer, so that the magnetic flux controlling magnetic material exhibits the magnetic saturation characteristics inherent to the magnetic material. be able to.

Since the rotor 1 is a circular coreless rotor made up mostly of the rotor winding 1a, and the space between the magnetic pole pieces 3 constitutes the air gap length, the permanent magnet 5 is one with a large coercive force. It is something to do.

The characteristics of such a permanent magnet with a large coercive force generally change depending on the temperature.

That is, the operating point of the permanent magnet changes along the operating line with a constant temperature coefficient as the temperature changes.

For example, the following table shows the temperature coefficient of residual magnetism for various types of permanent magnets.

An example of the magnetizing force on the operating line of a permanent magnet when the temperature changes from -20℃ to +80℃ is 220℃.
It changes like 0-1800 (Oe).

Therefore, the effective magnetic flux of the rotor of a DC rotating electric machine changes depending on the temperature, and its characteristics become different, so it is necessary to keep the air gap magnetic flux density constant regardless of the temperature.

The magnetic flux control magnetic body 6 is configured in advance so that a desired magnetizing force of several lO[009 or more is distributed. Next, the change in the magnetizing force of the permanent magnet due to the temperature change is 400 (Oe).
is adjusted as a decrease in magnetic permeability corresponding to an increment in the magnetizing force of the flux control magnetic body 6 whose magnetic flux density is constant due to saturation characteristics, so the air gap magnetic flux density can be kept constant.

FIG. 2 is a schematic sectional view of another embodiment of the present invention;
The same reference numerals as in the figure indicate the same parts, and 8 is a rectangular magnetic pole piece in which magnetic flux controlling magnetic bodies are laminated in the direction perpendicular to the magnetic path (horizontal direction in the paper) as shown in the figure, and the magnetic flux of the magnetic flux controlling magnetic body 8 and Since there is little difference from the air gap effective magnetic flux, there is an advantage that effective magnetic flux control can be performed.

9 is a yoke. In this embodiment, the magnetic pole pieces 8 are made of a flux controlling magnetic material such as permalloy, but the operation and effect are similar to the embodiment shown in FIG. 1.

Figure 3 shows the magnetization curve of 45% Ni permalloy as an example of a magnetic flux control magnetic material, and the magnetization force is several L 0 (
If the magnetic flux density exceeds 15 (KG), it becomes saturated.
), and even if the residual magnetism of the permanent magnet 5 changes due to temperature changes as described above, the air gap magnetic flux density can be kept constant by utilizing the saturated state.

FIG. 4 is a schematic side view of the circular rotor 1, where 10 indicates a commutator, and the rotor winding 1a is connected to the commutator 10 as in a general rotor.

5 and 6 are cross-sectional views of different embodiments of the above-mentioned circular mound-shaped rotor. In the embodiment shown in FIG. A thin protrusion 1 is formed on a thin cylindrical heat-resistant insulator 11 made of resin or the like.
2 is formed, and the winding 13 is placed in the groove between the protrusions 12. Since the protrusions 12 make the winding process easier, it is also possible to wind the wire with an automatic winding machine. It is also possible to insert a winding wound using a winding frame between the protrusions 12 like a general rotor winding.

Further, since the protrusion 12 serves only to position the winding 13 on the leather, it can be made extremely thin, and the entire protrusion 12 can be fixed with epoxy resin or the like.

In the embodiment shown in FIG. 6, a thin cylindrical insulator 14 is wrapped around the outer periphery of the rotating shaft 2, and a winding wire is molded and fixed to the outer periphery.

As mentioned above, in the present invention, since no rotor core is used at all, the inertia is extremely low, and since the ratio of the winding volume to the rotor is large, the torque-to-inertia ratio is large and high-speed response can be obtained. I can do it.

As explained above, since the present invention has a conical coreless rotor in which rotor windings are provided on one rotating shaft via a thin cylindrical insulator, the windings relative to the rotor volume are The volume ratio can be increased, the torque constant of the rotor can be increased, and since the rotor has no iron core, the inductance is extremely small and the rotor winding has a low electrical time constant, which is necessary for high-speed response. You can get the line.

Furthermore, since the rotor winding has a low inductance even when subjected to repeated peak human power, damage to the commutator is extremely small and the life of the commutator can be extended.

As mentioned above, since the rotor has no iron core, the gap length between the magnetic poles is long. However, by selecting the cross-sectional area and length of the permanent magnet, and the shape of the pole piece, and using a permanent magnet with high coercive force, The air gap magnetic flux density is obtained.

When such permanent magnets are used, changes in the magnetic properties due to temperature affect the characteristics of the DC rotating electric machine, but in the present invention, the magnetic path of the permanent magnets changes at the maximum operating temperature. Since a magnetic flux controlling magnetic material such as permalloy which becomes magnetically saturated is provided, the above-mentioned drawbacks can be prevented and stable characteristics can always be obtained.

As the magnetic material on the magnetic flux side, a soft magnetic material can also be used if a low-cost product is intended.

When the DC rotating electrical machine of the present invention is used as an electric motor, it is possible to stably obtain high response characteristics as described above, and when it is used as a generator, it is possible to obtain linearity of the characteristics between the rotation speed and the generated voltage. It is capable of generating a direct current voltage with excellent performance and low ripple, which is stable even against temperature changes.

[Brief explanation of drawings]

1 and 2 are schematic cross-sectional views of different actual cases of the present invention, and FIG. 3 is a 45% Ni as a magnetic flux controlling magnetic material.
Magnetization curve of permalloy Fig. 1 Fig. 4 is a side view of a circular mound-shaped coreless rotor according to an actual case of the present invention, and Figs. 5 and 6 are parts of different actual cases of a circular mound-shaped coreless rotor. They are a cross section and a cross section. 1 is a circular concentric rotor, Ia, 13.15 is a rotor winding, 2 is a rotating shaft, 3 is a magnetic pole piece, 4 is a mounting board, 5 is a permanent magnet, 6 is a magnetic flux control magnetic body, 7, 9 8 is a yoke, 8 is a magnetic pole piece made of a magnetic flux controlling material, and 10 is a commutator.

Claims (1)

[Claims] 1 A pair of field magnets consisting of a rectangular permanent magnet with a high coercive force attached to a ferromagnetic substrate and a magnetic pole piece, and a cylindrical magnet with a rotor winding attached to the rotating shaft via a cylindrical insulator. A direct current rotation characterized in that an iron core rotor is rotatably supported between the pair of field magnet structures, and a magnetic flux controlling magnetic body that is in a magnetically saturated state is disposed in a magnetic path of the field magnet structure. Electric machine.