JPH104660A - Ac generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly reliable magnet fixing structure, by providing magnets which are arranged between each magnetic pole of a core, excited by field coils, and increase the number of effective magnetic fluxes, and a magnet-retaining member which is fixed to the core, across the magnetic poles and retains the magnets by controlling the movement of the magnets. SOLUTION: Permanent magnets 41 are arranged between tooth sections 12 and 22 which are constituted as magnetic poles excited by field coils, namely, in the route of the leakage magnetic fluxes of a magnetic fluxes which are supplied by the field coils, and the external surfaces of the magnets 41 in the radial and peripheral directions are wrapped with nonmagnetic rings 32, so that the movement of the magnets 41 in the radial direction can be controlled by the outer peripheral sections of the rings 31. Since the magnets 41 are fixed to pole cores 11 and 21 through the rings 31, and the magnets 41 are arranged between the tooth sections 12 and 22, a part of the leakage magnetic fluxes can be utilized as an effective magnetic flux which contributes to power generation. In addition, the magnets 41 can be retained and fixed stably with the rings 31 for a long period.

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 the related art, a large annular permanent magnet is employed and fitted to the core to fix the permanent magnet to the core, or the permanent magnet is adhered to the core and the permanent magnet is fixed to the core. For this reason, when a ring-shaped permanent magnet is employed, a large amount of magnet material is required, so that there is a problem that the cost is high and an increase in weight is inevitable. Further, when the permanent magnet is bonded, it has been difficult to stably fix the permanent magnet for a long period of time in an environment where the permanent magnet rotates at a high speed and has a high temperature.

[0004] The present invention has been made to solve the problems of the prior art. An object of the present invention is to provide a structure for securely fixing a magnet.

[0005]

The present invention employs the following means to achieve the above object. According to the first aspect of the present invention, in an AC generator that excites a rotor core with a field coil, an effective magnetic flux that is disposed in a gap between the magnetic poles of the core that is excited by the field coil and that contributes to power generation is provided. A technical feature of an AC generator, comprising: a magnet to be increased; and a plate-like holding member that is fixed to the core and passed between the magnetic poles and that controls movement of the magnet to hold the magnet. Adopt means.

According to the present invention described above, the movement of the magnet is regulated by the plate-like holding member which is fixed between the magnetic poles and fixed to the core, and the magnet is held and fixed. Can be held and fixed. In particular, the plate-shaped holding member is fixed to the core as compared with a case where the magnet is directly bonded to the core with an adhesive or a case where a hole is formed in the magnet and the magnet is fixed to the core with a screw, and the magnet is inserted through this. Because of holding, reliable and stable holding and fixing become possible.

According to the second aspect of the present invention, the rotor includes:
A plurality of magnetic poles are arranged along a circumferential direction, and the holding member is fixed to the core by being passed radially outside between the magnetic poles, and the magnet is radially inside the holding member. The technical means that it is held in the system is adopted. In this manner, the holding member can be arranged radially outside the magnet. With this configuration, the movement of the magnet outward in the radial direction is regulated by the holding member, and in particular, the magnet that is likely to move outward in the radial direction can be reliably held and fixed. Especially,
There is an advantage that the centrifugal force acting on the magnet can be received by the holding member.

[0008] In the invention according to claim 3, the rotor is
A plurality of magnetic poles are arranged along a circumferential direction, the holding member is passed radially inward between the magnetic poles and is fixed to the core, and the magnet is radially outside the holding member. The technical means that it is held in the system is adopted. Thus, the holding member can be arranged radially inside the magnet. According to the present invention, the movement of the magnet inward in the radial direction is regulated by the holding member, and in particular, the magnet that is to move inward in the radial direction can be reliably held and fixed.

In the invention according to claim 4, the holding member employs technical means for pressing the magnet outward in the radial direction. According to the present invention, the movement of the magnet inward in the radial direction is regulated by the holding member, and in particular, the magnet that is to move inward in the radial direction can be reliably held and fixed. According to the invention described in claim 5, in an AC generator that excites a rotor core with a field coil, an effective magnetic flux that is disposed in a gap between the magnetic poles of the core that is excited by the field coil and contributes to power generation is provided. A magnet to be increased, and a holding member that is positioned radially outside the magnet in a gap between the magnetic poles, is passed between the magnetic poles, is fixed to the core, and holds the magnet by restricting movement of the magnet. A technical means called an alternator characterized by comprising:

According to the present invention, the holding member can be arranged radially outside the magnet. With this configuration, the movement of the magnet outward in the radial direction is regulated by the holding member, and in particular, the magnet that is likely to move outward in the radial direction can be reliably held and fixed. In particular, there is an advantage that the centrifugal force acting on the magnet can be received by the holding member.

According to a sixth aspect of the present invention, in an AC generator for exciting a rotor core with a field coil, the alternator is arranged in a gap between magnetic poles of the core excited by the field coil and contributes to power generation. A magnet that increases the effective magnetic flux;
And a holding member for holding the magnet by pressing the magnet toward the magnetic pole, the technical means being an AC generator.

According to the present invention, since the magnet is pressed and held from its rear surface toward the magnetic pole, the magnet can be stably held and fixed. According to a seventh aspect of the present invention, a technical means is adopted in which the holding member is fixed to the magnetic poles located on both sides of the gap between the magnetic poles. As in the present invention, the holding member can be fixed to the magnetic poles on both sides, and the plurality of magnets disposed between the magnetic poles can be reliably held and fixed.

According to an eighth aspect of the present invention, a technical means is adopted in which the magnet includes a permanent magnet. According to the present invention, the permanent magnet can be reliably and stably held between the magnetic poles.

[0014]

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. FIG. 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 view 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 vehicle alternator mainly includes pole cores 11 and 21 as iron cores, a nonmagnetic ring 31 as a holding member, a permanent magnet 41 as an auxiliary magnet, and electromagnetic excitation means. Field coil 45,
It is composed of a shaft 46 and fans 48 and 49.

The pole cores 11 and 21 are formed with a plurality of claw portions 12 and 22 which are claw-shaped magnetic poles protruding axially outward. The pole cores 11 and 21 have the claw portion 1
2, 22 are opposed to each other and are alternately positioned in the circumferential direction and are combined.
5, and is fitted and integrally assembled with a knurl provided on the shaft 46.

As shown in FIG. 4, the side face 32 of the non-magnetic ring 31 is in contact with the side faces 13 and 23 of the pawls 12 and 22 of the pole cores 11 and 21, and the bottom 33 is the pawl 12 , 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. .

On the inner side surface 35 of the outer peripheral portion 34 of the nonmagnetic ring 31, a permanent magnet 41 is provided with 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.

Further, in this embodiment, the permanent magnet 41 is wrapped around the outside in the radial direction and the circumferential direction 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.

In addition, the permanent magnet 41 is
The gap is smaller than the gap between them, and is held by the non-magnetic ring 31, so that it is held and fixed away from the claws 12, 22 as shown in the cross section of FIG. next,
The operation will be described. The magnetic flux generated by the field coil 45 passes through the pole cores 11 and 21 and
1. A stator (not shown) arranged close to the outer peripheral surface
, But also flows between the claw portions 12 and 22 of the opposing pole cores 11 and 21 as leakage magnetic flux.

Here, the claw portions 1 of the pole cores 11 and 21
Since the permanent magnet 41 is disposed between the first and second magnets 22 and 22, the leakage magnetic flux can be reduced, and a part of the leakage magnetic flux can be used as an effective magnetic flux contributing to power generation. As a result, an effective magnetic flux contributing to power generation Is increasing. As a result, as shown in FIG. 5, the claw portions 12, 22 of the pole cores 11, 21 are formed.
The output current with respect to the number of revolutions can be increased as compared with the case where the permanent magnet 41 is not provided during the operation.

As described above, since the nonmagnetic ring 31 as a plate-like member is passed between the claws 12 and 22 and the nonmagnetic ring 31 is fixed to the claws 12 and 22,
The permanent magnet 41 can be held and fixed by the non-magnetic ring 31, and the magnet can be stably held for a long period of time.
Can be fixed. The nonmagnetic ring 31 is located radially outward between the claw portions 12 and 22 and the permanent magnet 41 is disposed inside the ring, so that the centrifugal force acting on the permanent magnet 41 is used as a holding member. Non-magnetic ring 31
And can withstand high-speed rotation.

Further, the nonmagnetic ring 31 is
Since the arrangement is made so as to correspond only to the gap between the claws without covering the outer peripheral surface of 2, 22, that is, the surface facing the stator, the effective magnetic flux from the claws to the stator is not hindered. Further, by using a plastic magnet for the permanent magnet 41, peeling and breakage of the magnet at the time of assembling and after assembling can be prevented.

FIG. 6 is a partial perspective view showing a second embodiment of the non-magnetic ring and the like according to the present invention, and FIG. 7 is a view corresponding to FIG. 4 using the non-magnetic ring of FIG. It is a longitudinal cross-sectional view. 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 formed of resin, and the permanent magnet 41 is insert-molded. That is, in this embodiment, the permanent magnet 4
1 is covered with a non-magnetic ring 31, and the non-magnetic ring 31 is fixed to a claw as a magnetic pole, so that the permanent magnet 41 is also held and fixed.

Here, the outer peripheral portion 34 of the nonmagnetic ring 31
If there is a portion larger than the outer diameter surface of the claw portions 12 and 22 of the pole cores 11 and 21, the portion is cut or the like to minimize irregularities, and is substantially the same as the outer diameter surface of the claw portions 12 and 22. By using a radial surface, the effect of reducing wind noise can be increased. FIG. 8 is a partial sectional view showing a third embodiment of a non-magnetic ring or the like to which the present invention is applied.

In this embodiment, the permanent magnets 41 are disposed so as to be in direct contact with each other so as to fill the gaps between the side surfaces 13 and 23 of the claw portions 12 and 22 of the pole cores 11 and 21. The non-magnetic ring 31 is formed so as to contact the side surfaces 13 and 23 and the inner side surfaces 14 and 24 of the claw portions 12 and 22. Then, the non-magnetic ring 31 has a spring effect, and the claw portion 1 is constantly pressed against the permanent magnet 41.
They are sandwiched between the side surfaces 13 and 23 of 2,2.
By adopting a configuration in which such a magnet is pressed from the back surface toward the magnetic pole, the same effect as in the above-described embodiment can be obtained.

In such a configuration, the claw portion 12 as a magnetic pole,
A non-magnetic ring 31 as a plate-like member is passed over and fixed to the radially inner side between the two, and the non-magnetic ring 31 regulates the radially inward movement of the permanent magnet 41 as a magnet. 41 is held and fixed. Moreover, in this embodiment, the permanent magnet 4 is
1 to the outside in the radial direction to push the permanent magnet 41
Since the permanent magnets 41 are pressed against the rotors 2 and 22, the permanent magnet 41 can be reliably fixed from the time when the rotor is stopped to the time when the rotor is rotated at high speed.

FIG. 9 is a partial longitudinal sectional view showing a fourth 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.

FIG. 9 is a view showing a fourth example of the nonmagnetic ring and 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 Nonmagnetic ring 41 Permanent magnet 45 Field coil 46 Shaft 48, 49 Fan

Claims (8)

[Claims] 1. An AC generator that excites a rotor core with a field coil, wherein the magnet is disposed in a gap between magnetic poles of the core that is excited by the field coil and increases an effective magnetic flux contributing to power generation. An alternator comprising: a plate-like holding member that is fixed between the magnetic poles and fixed to the core and that holds the magnet by restricting movement of the magnet. 2. The rotor has a configuration in which a plurality of magnetic poles are arranged along a circumferential direction, and the holding member is fixed to the core so as to extend radially outward between the magnetic poles. The alternator according to claim 1, wherein the magnet is held radially inside the holding member. 3. The rotor is configured by arranging a plurality of magnetic poles along a circumferential direction, and the holding member is fixed to the core so as to extend radially inward between the magnetic poles, The alternator according to claim 1, wherein the magnet is held radially outside the holding member. 4. The alternator according to claim 3, wherein the holding member presses the magnet radially outward. 5. An AC generator for exciting a rotor core with a field coil, wherein the magnet is arranged in a gap between magnetic poles of the core excited by the field coil and increases an effective magnetic flux contributing to power generation. And a holding member that is positioned radially outward of the magnet in a gap between the magnetic poles, is passed between the magnetic poles, is fixed to the core, and controls movement of the magnet to hold the magnet. An alternator characterized by the following. 6. An AC generator for exciting a rotor core with a field coil, wherein the magnet is arranged in a gap between magnetic poles of the core excited by the field coil and increases an effective magnetic flux contributing to power generation. And a holding member disposed on the back of the magnet and holding the magnet by pressing the magnet toward the magnetic pole. 7. The alternator according to claim 1, wherein the holding member is fixed to the magnetic poles located on both sides of a gap between the magnetic poles. 8. The alternator according to claim 1, wherein the magnet includes a permanent magnet.