JPS5829358A - Composite permanent magnet for field system - Google Patents

Abstract

PURPOSE:To improve output by forming an arcuate permanent magnet by the section of a material having high coercive force and the section of a material having high residual magnetic flux density. CONSTITUTION:One part 6b of the arcuate permanent magnet 6 for the field system is formed by the material having high coercive force, and the other part 6a is shaped by the material having high residual magnetic flux density. The height h1 of the material section 6a having high residual magnetic flux density is 1.5-1.6 times as long as the height of a rotor, and the height h2 of the material section 6b having high coercive force is 1.1-1.2 times as long as the height of the rotor. Accorldingly, the rotary output o the rotor is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a field composite permanent magnet, and particularly relates to a field composite permanent magnet used in a permanent magnet rotating machine such as a permanent magnet generator or a permanent magnet motor. An example of a conventional permanent magnet rotating machine will be explained based on FIG. 1.

Here, FIG. 1 is a cross-sectional view of a permanent magnet type rotating machine.

In the figure, numeral 1 denotes a rotor composed of an armature core around which armature windings are wound and a commutator, and is held by an end bracket via a bearing. 2 is a housing, and 3 and 4 are field permanent magnets fixed to the housing 2.

This type of permanent magnet rotating machine has also been miniaturized in recent years.
There is a strong demand for higher performance and higher output. However, in order to improve the output, it is necessary to use a permanent magnet with a high residual magnetic flux density (Br) as a permanent magnet for the field.On the other hand, when trying to improve the output, the demagnetizing field due to armature reaction increases, and the coercive force decreases. It becomes necessary to use a permanent magnet with high magnetic properties (iHc) as a field permanent magnet.

However, rare earth cobalt sintered permanent magnets or
The basic composition is MO・nFe203 (y14, Ea.

One or a mixture of two or more of Sr and Pb, n=5
~6) Even if we consider hexagonal oxide sintered permanent magnets mainly composed of
A one-piece permanent magnet that combines c) is not easily obtained;
In rotary machines that use conventional permanent magnets with the same characteristics as field permanent magnets, there are certain limits to performance improvements such as increased output and torque.

Composite permanent magnets have been proposed as field permanent magnets that solve the above-mentioned limitations of performance improvement.

This composite permanent magnet for field use is basically made by using two types of raw materials having the same basic composition to form an integral composite permanent magnet for field use in some way, and then sintering it at high temperature. , a material having a higher residual magnetic flux density (Br) than the other and a material having a higher coercive force (iHc) than the other are fixed to each other.

The above composite permanent magnet for field will be explained based on FIGS. 2 to 5. Here, FIGS. 2 and 3 are a plan view and a side view of the composite permanent magnet for field, The figure is a cross-sectional view of a magnetic rotating machine using this field composite permanent magnet, and FIG. 5 is a vertical cross-sectional view taken along the line A--A in FIG. 4.

In FIGS. 4 and 5, the same reference numerals as in FIG. 1 indicate equivalent parts.

In Figures 2 to 5, 5 is an arc-shaped permanent magnet, and 5a
is a permanent magnet that has a higher residual magnetic flux density (Br) than 5b, 5b is a permanent magnet that has a higher coercive force (iHc) than 5a, and the arc-shaped permanent magnet 5 is a permanent magnet that has a higher residual magnetic flux density (Br) than that of 5b.
b is a field composite permanent magnet coupled to the arcuate permanent magnet 5 to its full height.

The reason why the permanent magnet 5b having a higher coercive force (iHc) than the permanent magnet 5a is combined is to counter demagnetization field due to increased armature reaction caused by increasing the output of the rotor 1,
The height of the rotor 1 is 1.2 to 1.3 times the height of the rotor 1. However, as shown in Fig. The reaction range exerted on the magnet 5 is approximately 1.1 times the height of the rotor 1.

Therefore, the height of the high 1Hc material 5b coupled as a countermeasure against the increase in the demagnetizing field due to the armature reaction may be 1.1 to 1.2 times the height of the rotor 1. As a result, the amount of coupling of the permanent magnet 5a having a high residual magnetic flux density (Br), which aims to increase the output of the rotor 1, decreases, so the increase in output is inhibited.

An object of the present invention is to provide a composite permanent magnet for a field, which eliminates the above-mentioned drawbacks and can greatly improve the output of a permanent magnet rotating machine.

A feature of the present invention is that a part of the arc-shaped permanent magnet is made of a material that has a higher coercive force (iHc) than the other part, and the other part is made of a material that has a higher residual magnetic flux density (Br) than the part. , the height of the material portion having the above residual magnetic flux density (Br) is 1.5 to 1.6 times the height of the rotor, and the material has a high coercive force (Br).
The height of the material portion with iHc) is 1.1 of the height of the rotor.
Composite permanent magnet for field having 1 to 1.2 times.

Embodiments of the present invention will be described below based on the drawings. Here, FIGS. 6 and 7 are a plan view and a side view of a field composite permanent magnet according to an embodiment. In Fig. 7, 6 has a higher B than 6b and an r material 6a,
This is an arcuate permanent magnet made of a material 6b having a higher iHc than 6a.

The height h2 of the 1Hc material 6b is, as mentioned above, because the range of reaction that the rotor 1 exerts on the field composite permanent magnet 6 is approximately 1.1 times the height of the rotor 1. , 1.1 to 1.2 times that of rotor 1. therefore,
The height hl of the high Br material 6a can be made smaller than the conventional one by 1.2 to 1.3 times, and the arc-shaped permanent magnet 6 can have a height hl of the high Br material 6a corresponding to the reduced height.

For this reason, the height of the high Br material 6a is set to L5~1 of the rotor 1.
．． As explained above, the composite permanent magnet for the field according to this embodiment has the effect of reducing the armature reaction that occurs to increase the rotational output of the rotor of a magnetic rotating machine. The rotor height ranges from 1.1 to 1.2
The height of the high 1Hc material is doubled, and the height of the high Br material is 1,5 times higher than the height of the high Brtt of the conventional field composite permanent magnet.
It is designed so that it can be taken up to 1.6 times.

Therefore, a magnetic rotating machine using the above field composite permanent magnet can increase the output of the rotor.

As described above, the present invention can be expected to provide a composite permanent magnet for a field that can improve the output of a permanent magnet type rotating machine, and has excellent practical effects. It can be said that.

[Brief explanation of the drawing]

11] is a cross-sectional view of a permanent magnet type rotating machine, and FIGS. 2 and 3 are respectively a plan view and a side view of a conventional field composite permanent magnet. 5 is a cross-sectional view of a magnetic rotating machine using permanent magnets, FIG. 5 is a longitudinal section taken along the line A-A in FIG. 4, and FIGS. 6 and 7 are cross-sectional views of a magnetic rotating machine according to an embodiment of the present invention FIG. 4 is a plan view and a side view of a composite permanent magnet for use in the present invention. 1... Rotor, 6... Arc-shaped permanent magnet, 6a.
...High Br permanent magnet 6b...High Br permanent magnet. Patent Applicant Hitachi Metals Co., Ltd. Representative Patent Attorney Matsu Takemoto No. 1
Figure 2 Figure 3

Claims (1)

[Claims] A part of the arc-shaped permanent magnet has a higher coercive force (iH) than the other part.
a), and the other part is made of a material having a higher residual magnetic flux density (Br) than the above-mentioned part, and the height of the material having the high residual magnetic flux density (Br) is 1 of the height of the rotor. .5
~1.6 times the height of the rotor, and the height of the material having high coercive force (iHc) is 1.1 to 1.2 times the height of the rotor.