JPS5814691Y2 - Field of rotating electric machine - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a magnetic field of a rotating electric machine such as a DC motor or a magnet generator.

Conventionally, this type of field magnet was assembled by alternately arranging magnetic pole bodies and permanent magnets in a ring shape, but since the permanent magnets and each magnetic pole body were separated, a holding jig was required for assembly, and assembly was difficult. Not only does this require a large amount of work, but the magnetic flux density around the armature is extremely different between the magnetic pole bodies and between the magnetic pole bodies, resulting in large cogging torque and, in the case of a generator, an output nozzle. There is a big drawback.

For this reason, as shown in FIG. 1, it has been proposed to use an iron core 1 in which the inner sides of the magnetic poles 2 are connected by a connecting part 3, and a permanent magnet 4 is fitted on the outside of the connecting part. 3, magnetic flux leakage becomes large, and a permanent magnet larger than necessary must be used.

Note that 5 is an armature.

Therefore, as shown in Fig. 2, it has been proposed to provide a groove 6 in the connecting part 3 to reduce the path of leakage magnetic flux and to support the permanent magnet 4 on both sides of the groove. Since the parts near both ends of the magnet are in contact with the connecting part, a considerable amount of magnetic flux leaks as shown by the arrow, which inevitably reduces the efficiency of using the permanent magnet.

The present invention has been developed in consideration of the above-mentioned drawbacks, and will be described with reference to embodiments shown in the drawings.

In FIG. 3, 1 is an iron core, 2 is a magnetic pole, and 3 is a connecting portion between magnetic poles. A plurality of magnetic poles 2, for example, 4, are connected by connecting portions 3, and appropriate terminals are connected to both ends of the connecting portion 3. A curved portion (or inclined portion) 7 is provided.

These may be manufactured by machining a plate material of a predetermined thickness, or may be made by punching electric iron plates into a predetermined shape and laminating and fixing them to a required thickness.

The permanent magnet 4 is inserted into the space between the magnetic poles 2 in contact with the side surface of the magnetic pole, and the inner corner 4a engages with the base of the side surface of the magnetic pole of the curved portion 7 to form a gap between the connecting portion 3 and the permanent magnet 4. permanent magnet 4
A magnetic gap G is formed over the entire length of the inner surface.

This permanent magnet 4 is magnetized so that both sides of one magnetic pole 2 have the same polarity.

Numerals 8 are protrusions provided at both outer ends of each magnetic pole 2 to prevent the permanent magnets 4 from flying out.

The narrower the connecting portion 3 is, the less magnetic flux leakage occurs through the connecting portion 3 as a passage, but the mechanical strength is also reduced.
0.2 to 0.3 mm (size), 1. If it is set to about Qmm, mechanical holding force can be obtained, and
It is saturated with a small amount of magnetic flux, and leakage of magnetic flux is not a practical problem.

It is sufficient to fix the permanent magnet 4 by simply inserting it into the space between the magnetic poles 2 due to magnetic attraction, but if necessary, a small amount of adhesive may be used.

In addition, if the magnetic gap G is filled with a non-magnetic metal such as copper with good thermal conductivity, or a synthetic resin mixed with metal powder, it is possible to reduce the axial temperature gradient due to the heat received from the armature. It is also useful for improving rectification characteristics due to its damper effect.

FIG. 4 shows another embodiment of the present invention, in which the outer protrusion 8 of the magnetic pole 2 in the previous embodiment is further extended to form an outer connecting portion 9, which eliminates magnetic flux leakage to the outside of the machine due to the shielding effect. , mechanical strength is improved.

The engagement between the outer connecting portion 9 and the permanent magnet 4 also occurs in the inner connecting portion 3.
Similarly, the corners of the permanent magnet 4 are engaged with each other, and a magnetic gap G' is also formed between the outer connecting portion 9 and the permanent magnet.

This gap G' may also be filled with a material having good thermal conductivity.

As described above, the field according to the present invention is provided with curved parts (or inclined parts) at both ends of the connecting part that connects the magnetic poles, so that the surface of the connecting part on the permanent magnet side is connected to the side surface of the magnetic poles by the curved part. The corners of the permanent magnet are held in contact with the base of the side surface of the magnetic pole of the curved portion, and the permanent magnet and the connecting portion are in contact only at the base, forming a magnetic gap over the entire length of the side surface of the permanent magnet. Therefore, it is easy to assemble and handle, easy to manufacture, and has excellent mass productivity.There is also almost no magnetic flux leaking from the side of the permanent magnet, cogging torque or output voltage ripple is small, and there is an air gap G. Therefore, it has the advantage of less demagnetization of the permanent magnet due to armature reaction.

[Brief explanation of the drawing]

1 and 2 are front views showing a conventional example, FIG. 3 is a front view of an embodiment of the present invention, and FIG. 4 is a front view of another embodiment. 1 is the iron core, 2 is the magnetic pole, 3 is the connecting part, 4 is the permanent magnet, 4a
is an inner corner of the permanent magnet, 5 is an armature, 6 is a groove, 7 is a curved portion, 8 is a protrusion, and 9 is an outer connecting portion.

Claims (1)

[Scope of utility model registration request] An iron core 1 integrally comprising a plurality of magnetic poles 2 and a connecting portion 3 that connects at least the inner sides of the magnetic poles is inserted between adjacent magnetic poles and magnetized so that both sides of each magnetic pole have the same polarity. A curved part 7 is provided at both ends of the connecting part of the iron core, and the inner corner 4a of the permanent magnet is fixed and held at the base of the magnetic pole side of the curved part 7, so that the inner surface of the permanent magnet and the connecting part 3. A magnetic field for a rotating electric machine characterized by providing a magnetic gap G between the magnetic field and the rotating electric machine.