JP2865092B2 - AC generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC generator provided with a magnet between magnetic poles, and is particularly suitable for a vehicle AC generator.

[0002]

2. Description of the Related Art In recent years, low noise and high output have been demanded as social needs for vehicle alternators. Here, as a technique for improving the output of the vehicle alternator, for example, a technology disclosed in Japanese Patent Application Laid-Open No. 61-85045, “Vehicle Alternator” is known.

[0003]

In the rotor of the automotive alternator disclosed in the above publication, an effective magnetic flux contributing to power generation is generated by a permanent magnet as an auxiliary magnet provided between the claw portions of a pole core serving as claw-shaped magnetic poles. In addition, the output can be improved, the physique can be reduced in size, and the like. However, in such a conventional technique, when the magnet material is exposed on the outer periphery of the rotor, a small foreign matter bites into the magnet to cause a crack, or when a partial loss occurs, the broken pieces are removed by centrifugal force. It may be skipped towards the stator and cause further problems in the gap.

[0004] There is a problem that such damage to the magnet and a decrease in magnetic performance cause a decrease in power generation performance as an AC generator. The present invention has been made to solve the problems of the related art. SUMMARY OF THE INVENTION An object of the present invention is to provide an AC generator that can prevent damage to a magnet and decrease magnetic performance, exhibit required power generation performance, and maintain the power generation performance.

SUMMARY OF THE INVENTION It is an object of the present invention to prevent a magnet from being damaged or to prevent an incidental trouble caused by the magnet from being damaged.

[0006]

The present invention employs the following means to achieve the above object. According to the first aspect of the present invention, in the AC generator in which the rotor core is excited by the field coil, the rotor is combined with the claws facing each other.
Has it been pole core, different by the field coil
A magnet to increase the effective magnetic flux that contributes to power generation is provided between said pole core to be excited to a polarity that, the protective member and Bei <br/> possible to obtain a protecting the magnets disposed radially outward of said magnet The technical means of an alternator characterized by the following is adopted.

According to a second aspect of the present invention, in an AC generator having a rotor having a plurality of magnetic poles excited by a field coil, the rotor has a pair of claws serving as the magnetic poles.
Has a pole core combined by countercurrent, in that a magnet to increase the effective magnetic flux that contributes to power generation in the radially inner protective member disposed over the radially outer gap between the magnetic poles adjacent The technical means of the featured alternator is adopted. According to the third aspect of the present invention, in the AC generator including a rotor having a plurality of magnetic poles excited by a field coil, the rotor has a claw as the magnetic pole
An alternator having a pole core combined with parts facing each other, wherein a magnet that is protected by a protection member on a radially outer side and increases effective magnetic flux contributing to power generation is arranged between the adjacent magnetic poles. It adopts the technical means of:

[0008] By adopting any one of the first, second, and third means, the effective magnetic flux contributing to power generation can be increased, and the magnet is obtained because the magnet is protected by the protection member. High power generation performance can be reliably obtained and can be maintained. In addition,
According to the protective member, for example, protection against mechanical stress applied from the radial outside of the magnet, protection by preventing scattering to the outside when a crack occurs in the magnet, and protection against electromagnetism can be selectively performed. And the material of the protective member can be appropriately selected.

For example, in the case where the magnet is arranged in the gap between the magnetic poles, the protective member is arranged radially outside of the magnet, so that mechanical stress is applied to the outside of the rotor in an assembly process for handling the rotor. Can be prevented from being applied directly to the magnet even if it is applied, and the magnet can be protected to prevent its cracking. Similarly, even if the foreign matter is caught between the rotor and the stator even after being assembled as an AC generator, it is possible to prevent the foreign matter from directly hitting the magnet and damage the magnet. In addition, even if the magnet is cracked for some reason, the protection member is arranged radially outward of the magnet, so that the fragments can be prevented from scattering radially outward. In addition, it is possible to obtain an effect of shielding a magnet from an electromagnetic effect received from a stator or the like disposed opposite to the rotor.

According to the invention described in claim 4, the technical means that the magnet is a permanent magnet is employed. As described above, a permanent magnet can be selected as the magnet, and in particular, since the magnet is protected by the protective member, a wide range of usable magnet materials can be used to meet the demands of performance, cost, etc. as a generator. it can.

According to the fifth aspect of the present invention, the technical means that the protection member is a non-magnetic material is employed. According to the present invention, the magnet can be protected without affecting the magnetic performance of the rotor. For example, a resin or a non-magnetic metal can be used as the non-magnetic material.

According to the sixth aspect of the present invention, the technical means that the protective member is made of metal is employed. According to the present invention, a material having excellent mechanical strength, which is a general property as a metal, or excellent conductivity can be selected. For example, the magnet can be strongly protected from a mechanical external force. In addition, when a magnetic flux from the stator facing the rotor tries to act on the magnet, it can function as a magnetic shield to magnetically protect the magnet.

According to the seventh aspect of the present invention, the technical means that the protective member is a plate-like member is employed.
According to the invention, it is possible to employ a plate-like member, Ru can protect magnet with a simple configuration.

[0014]

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on some examples. First, a first embodiment will be described. 1 is a longitudinal sectional view showing a configuration of a rotor of an automotive alternator according to the present invention, and FIG. 2 is a portion showing a state where a pair of pole cores, a non-magnetic ring and a permanent magnet are assembled. It is a perspective view. FIG. 3 is a partial perspective view showing a nonmagnetic ring in which permanent magnets are disposed on the inner surface,
FIG. 4 is a partial vertical sectional view taken along the line IV-IV of FIG.

The rotor 10 of the automotive alternator mainly includes pole cores 11 and 21 as iron cores, a non-magnetic ring 31, a permanent magnet 41 as an auxiliary magnet, and electromagnetic excitation means. Field coil 45 and shaft 4
6 and fans 48 and 49. The pole cores 11 and 21 are respectively formed with a plurality of claw portions 12 and 22 that are claw-shaped magnetic poles protruding in the axial direction on the outer peripheral side. The pole cores 11 and 21 are combined with the claw portions 12 and 22 facing each other so as to be alternately positioned in the circumferential direction. The field coils 45 are sandwiched in an internal space formed therein, and the knurls provided on the shaft 46 are provided. And are integrally assembled.

As shown in FIG. 4, the non-magnetic ring 31 has a side surface 32 in contact with the side surfaces 13, 23 of the pawl portions 12, 22 of the pole cores 11, 21, and a bottom portion 33 thereof. , 22 are formed so as to be in contact with the inner side surfaces 14, 24, and to fill the space between the opposing claw portions 12, 22 and have the same outer diameter surface as the outer diameter surface of the claw portions 12, 22. .

A permanent magnet 41 is provided on the inner side surface 35 of the outer peripheral portion 34 of the nonmagnetic ring 31 by a field coil 45.
And a gap. The permanent magnet 41 is magnetized so as to prevent a leakage magnetic flux between the magnetic poles of the claw portions 12 and 22 of the pole cores 11 and 21. As described above, the permanent magnet 41 is arranged between the claw portions 12 and 22 as the magnetic poles excited by the field coil 45, that is, in the leakage flux path of the magnetic flux supplied by the field coil 45.

On the surface of the permanent magnet 41, a plate-shaped non-magnetic ring 31 is arranged.
A side surface portion 32 of the non-magnetic ring 31 is disposed between the non-magnetic ring 31 and the claw portions 12 and 22, and an outer peripheral portion 34 of the non-magnetic ring 31 is disposed radially outside of the permanent magnet 41. 41 covers the outer surface in the radial direction. In addition, the nonmagnetic ring 31 is arranged such that the bottom 33 is in contact with the inner side surfaces 14, 24 of the claws 12, 22.
It is fixed to. For this reason, the outer peripheral portion 34 of the nonmagnetic ring 31 is disposed between the claws 12 and 22 and covers the radially outer side of the gap between the claws 12 and 22. The permanent magnet 41 is arranged radially inside the outer peripheral portion 34. For this reason, the outer peripheral portion 34 protects the permanent magnet 41 by preventing the permanent magnet 41 from being exposed to the outside in the radial direction, and furthermore, even if the permanent magnet 41 is cracked, the fragments are directed outward in the radial direction. Prevents scattering.

Further, in this embodiment, the permanent magnet 41 is wrapped radially outwardly and circumferentially by the non-magnetic ring 31. When the permanent magnet 41 is assembled to the pole cores 11 and 21, the outer peripheral portion 34 of the non-magnetic ring 31 is provided. The movement of the permanent magnet 41 to the outside in the radial direction is regulated by this. Therefore,
The permanent magnet 41 is fixed to the pole cores 11 and 21 via the non-magnetic ring 31.

Next, the operation will be described. Field coil 4
5 is supplied to a stator (not shown) disposed close to the outer peripheral surfaces of the pole cores 11 and 21 through the pole cores 11 and 21. 22 also flows as leakage magnetic flux.

Here, the claw portions 1 of the pole cores 11 and 21
Since the permanent magnet 41 is provided between the second and the second 22, the leakage magnetic flux can be reduced, and a part of the leakage magnetic flux can be used as an effective magnetic flux. As a result, as shown in FIG. 5, the output current with respect to the rotation speed can be increased as compared with the case where the permanent magnet 41 is not disposed between the claw portions 12 and 22 of the pole cores 11 and 21.

As described above, the nonmagnetic ring 3
1 is the side surface 1 of the pawl portions 12 and 22 of the pole cores 11 and 21
Fill the gaps between 3 and 23 and the outer peripheral portion 3
4 is formed so as to be the same as the outer diameter of the claw portions 12 and 22. Therefore, the rotor 10 of this vehicle alternator is
Are claw portions 12, 2 of the pole cores 11, 21 even if they rotate at a high speed.
No wind noise occurs because there is no centrifugal fan effect due to 2.

Further, a gap is provided over the entire circumference between the non-magnetic ring 31 and the field coil 45, and the ventilation inside the pole cores 11 and 21 is not impaired. Does not adversely affect cooling. Further, since the nonmagnetic ring 31 covers the outside of the permanent magnet 41 in the radial direction, the permanent magnet 41 is protected from the outside in the radial direction. In addition, the non-magnetic ring 31 is
The permanent magnet 41 is also protected from the claw portions 12 and 22 by being disposed between the claw portions 12 and 22. As described above, the surface of the main part of the permanent magnet 41 is protected by the non-magnetic ring 31, and the non-magnetic ring 31 functions as a plate-shaped protection member.

Further, by using a plastic magnet for the permanent magnet 41, peeling and breakage of the magnet during and after assembly can be prevented. FIG.
FIG. 7 is a partial perspective view showing a second embodiment of the nonmagnetic ring and the like according to the present invention, and FIG. 7 is a partial longitudinal sectional view corresponding to FIG. 4 using the nonmagnetic ring of FIG. The components having the same functions as those of the above-described embodiment will be described with the same reference numerals.

The non-magnetic ring 31 is made of resin, and the permanent magnet 41 is insert-molded. That is, in this embodiment, all surfaces of the permanent magnet 41 are covered and protected by the nonmagnetic ring 31. here,
The pole cores 11 and 2 are attached to the outer peripheral portion 34 of the nonmagnetic ring 31.
When there is a portion larger than the outer diameter surface of the claw portions 12 and 22, the portion is cut or the like to minimize irregularities, and the outer diameter surface of the claw portions 12 and 22 is made substantially the same as the outer diameter surface. Thereby, the effect of reducing wind noise can be increased.

FIG. 8 is a partial longitudinal sectional view showing a third embodiment of the nonmagnetic ring and the like according to the present invention. When the non-magnetic ring 31 is formed of a non-magnetic metal body and the permanent magnet 41 is formed of a metal magnet, the outer peripheral surface of the permanent magnet 41 disposed on the inner surface 35 side of the non-magnetic ring 31 By integrally forming at least a part of the contact surface with the non-magnetic ring 31 with the buffer member 42 or an adhesive interposed therebetween, the interference between the non-magnetic ring 31 and the permanent magnet 41 is eliminated, and An effect similar to that of the embodiment can be obtained. Thus, the effect of protecting the magnet can be improved by interposing a buffer member or an adhesive in addition to the non-magnetic ring 31.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a configuration of a rotor of an automotive alternator according to a specific embodiment of the present invention.

FIG. 2 is a partial perspective view showing a state where a pair of pole cores, a nonmagnetic ring, and a permanent magnet are assembled.

FIG. 3 is a partial perspective view showing a nonmagnetic ring in which a permanent magnet is provided on an inner surface.

FIG. 4 is a partial longitudinal sectional view taken along the line IV-IV in FIG. 2;

FIG. 5 is an explanatory diagram showing a relationship between a rotation speed and an output current depending on the presence or absence of a permanent magnet.

FIG. 6 shows a second example of the nonmagnetic ring or the like according to the present invention.
FIG. 3 is a partial perspective view showing the embodiment of FIG.

FIG. 7 is a partial longitudinal sectional view corresponding to FIG. 4 using the nonmagnetic ring of FIG. 6;

FIG. 8 is a third view of a non-magnetic ring or the like according to the present invention;
FIG. 4 is a partial longitudinal sectional view showing the example of FIG.

[Explanation of symbols]

 Reference Signs List 10 Rotor of vehicle alternator 11, 21 Pole core 12, 22 Claw (magnetic pole) 31 Non-magnetic ring 41 Permanent magnet 45 Field coil 46 Shaft 48, 49 Fan

Claims (7)

(57) [Claims] 1. An AC generator in which a rotor core is excited by a field coil, wherein the rotor is a pole core combined with claws facing each other.
Has A, the port that is excited in different polarities by said field coil
A magnet to increase the effective magnetic flux that contributes to power generation is provided between the-core, AC generator, characterized in that it comprises a protective member for protecting the magnet is provided radially outward of said magnet. 2. An alternator comprising a rotor having a plurality of magnetic poles excited by a field coil, wherein the rotor is assembled with claws serving as the magnetic poles facing each other.
Have I been pole core, characterized in that a magnet to increase the effective magnetic flux that contributes to power generation in the radially inner protective member disposed over the radially outer gap between the magnetic poles adjacent Alternator. 3. An alternator having a rotor having a plurality of magnetic poles excited by a field coil, wherein the rotor is assembled with claws serving as the magnetic poles facing each other.
Have I been the pole core, is radially outward is protected by the protective member, the alternator being characterized in that disposed between the adjacent magnetic poles of the magnet to increase the effective magnetic flux that contributes to power generation. 4. The alternator according to claim 1, wherein the magnet is a permanent magnet. 5. The alternator according to claim 1, wherein the protection member is a non-magnetic material. 6. The alternator according to claim 1, wherein the protection member is made of metal. 7. The alternator according to claim 1, wherein the protection member is a plate-like member.