JP5924913B2 - Generator - Google Patents

Description

  The present invention relates to a generator, and more particularly to an AC generator mounted on a vehicle.

  An automobile is provided with an alternator that converts the power of the output shaft of the engine into electric power. The alternator includes an AC generator and a rectifier (rectifier) that converts AC power output from the AC generator into DC power. The DC power generated by the alternator is consumed by an electric load such as a headlight and stored in a battery.

  The AC generator includes a rotor and an annular stator that surrounds the rotor.

  FIG. 3 is a schematic side view of a rotor provided in a conventional AC generator.

  The rotor 81 is fixed to the shaft 82 and is provided so as to be rotatable integrally with the shaft 82. The rotor 81 includes a rotor coil 83 wound around a shaft 82 and a pair of pole cores 84 and 85 provided so as to sandwich the rotor coil 83 from both sides in the rotation axis direction (axial direction of the shaft 82). I have.

  The pole cores 84 and 85 are integrally formed using iron. The pole cores 84 and 85 are formed with a plurality of claw-shaped magnetic poles 86 and 87 that protrude in directions opposite to each other. The claw-shaped magnetic poles 86 and 87 mesh with each other and are alternately arranged in the circumferential direction.

  Two slip rings 88 and 89 are fixed to one end of the shaft 82. Two brushes 91 and 92 are provided so as to be slidable with the slip rings 88 and 89, respectively. The brushes 91 and 92 are electrically connected to the battery via a regulator for controlling the generated voltage. When a field current is supplied from the battery to the rotor coil 83 through the brushes 91 and 92 and the slip rings 88 and 89, the claw-like electrode 86 of one pole core 84 is magnetized to the N pole, and the claw-like shape of the other pole core 85 is obtained. The electrode 87 is magnetized to the south pole.

  Then, when the rotation of the output shaft of the engine is transmitted to the shaft 82 and the rotor 81 rotates together with the shaft 82, a current due to electromagnetic induction flows through a stator coil provided in the stator.

Japanese Patent Laid-Open No. 9-154262

  In the rotor 81 having the configuration shown in FIG. 3 (so-called comb rotor), in order to increase the output of the AC generator, the rotor 81 must be enlarged in the rotational radial direction and the rotational axis direction. There is no freedom. For example, due to the space in the engine room where the alternator is placed, if you want to reduce the size of the alternator in the radial direction, reduce the size of the alternator in the radial direction, while reducing the size of the alternator in the rotational axis direction. It is not easy to obtain the same output as before by increasing the size. This is because the magnetic path connecting the pole cores 84 and 85 in the direction of the rotation axis must be made thicker as the axial length becomes longer in order to prevent an increase in the magnetic resistance.

  Further, in the AC generator having the rotor 81, the slip rings 88 and 89 and the brushes 91 and 92 for supplying power to the rotor coil 83 are provided, so that the size in the rotation axis direction is large and the number of parts is large. There is also a problem that there are many.

  An object of the present invention is to provide a power generator capable of reducing the cost by reducing the size and the number of parts.

In order to achieve the above object, a power generator according to the present invention includes a rotating shaft, a rotor provided to be rotatable integrally with the rotating shaft, and a stator provided around the rotor. The rotor is formed with a rotor yoke through which the rotation shaft is inserted in a central portion so as not to be relatively rotatable, and a plurality of rotor magnetic poles protruding from the rotor yoke in the radial direction. The stator includes an annular stator yoke that surrounds the rotor in the circumferential direction of rotation, a stator core on which a plurality of stator magnetic poles projecting inside the stator yoke, and a stator coil that is concentratedly wound around each stator magnetic pole. ing. The plurality of stator magnetic poles constitute a plurality of stator magnetic pole groups at positions separated from each other. Each stator magnetic pole group includes the number of stator magnetic poles corresponding to the number of phases. The stator magnetic poles constituting each stator magnetic pole group are provided at a predetermined interval, and the plurality of stator magnetic pole groups are separated from each other by a predetermined interval. The generator includes a first field coil for magnetizing the stator magnetic pole group to N pole, and the stator magnetic pole group different from the stator magnetic pole group magnetized to the N pole to S pole. And a second field coil for magnetizing.

  When a field current flows through the first field coil and the second field coil, the stator magnetic pole group is magnetized to the N pole, and another stator magnetic pole group is magnetized to the S pole. As the rotor rotates, when the rotor magnetic pole faces the stator magnetic pole magnetized to the N pole, and when another rotor magnetic pole faces the stator magnetic pole magnetized to the S pole, the magnetic flux is magnetized to the N pole. The stator magnetic poles and the stator magnetic poles magnetized to the S pole pass through the rotor / stator yoke. As a result, an induced current flows through the stator coils concentratedly wound around these stator magnetic poles.

  Since the plurality of stator magnetic pole groups are separated from each other, the stator yoke can be formed linearly between the stator magnetic pole groups. For example, when there are two stator magnetic pole groups, the stator yoke can be formed linearly between the two stator magnetic pole groups. Therefore, the size of the stator in the radial direction can be reduced as compared with a stator in which the stator yoke is formed in an annular shape.

  Since the rotor is not a so-called comb rotor, the size in the rotational axis direction can be increased while the size in the rotational radial direction is reduced. Therefore, the same output as the conventional generator can be ensured by reducing the size of the rotor and the stator in the radial direction and increasing the size in the rotational axis direction.

  Further, unlike the configuration in which the field coil is provided in the rotor, a slip ring and a brush are not required. Therefore, even if the size of the rotor in the rotation axis direction is increased, the increase in the size can be offset by omitting the space necessary for the arrangement of the slip ring, and the size of the generator as a whole increases in the rotation axis direction. Can be prevented.

  Therefore, when the generator is used in an alternator mounted on an automobile, it is desired to secure the output of the generator while reducing the size of the generator in the radial direction due to the space in the engine room where the alternator is placed. It can respond to the request.

  Furthermore, since a slip ring and a brush are unnecessary, the number of parts can be reduced. As a result, the cost can be reduced by reducing the number of parts.

  Further, the magnetic flux passing through the stator yoke between the stator magnetic pole group magnetized at the N pole and the stator magnetic pole group magnetized at the S pole is distributed to one side portion and the other side portion of the stator yoke. Therefore, the thickness of the stator yoke can be reduced. As a result, the weight of the stator can be reduced.

  According to the present invention, the generator can be reduced in size and weight by reducing the size and weight of the stator. Further, the cost of the generator can be reduced by reducing the number of parts.

FIG. 1 is a cross-sectional view of a generator according to an embodiment of the present invention cut along a cross section orthogonal to a rotation axis. FIG. 2 is a cross-sectional view when the generator is cut along a cross section along the rotation axis. FIG. 3 is a schematic side view of a rotor provided in a conventional AC generator.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view of a generator according to an embodiment of the present invention cut along a cross section orthogonal to a rotation axis. FIG. 2 is a cross-sectional view when the generator is cut along a cross section along the rotation axis. In FIGS. 1 and 2, hatching is partially omitted in order to avoid complicated drawings.

  The generator 1 is a three-phase AC generator. The generator 1 includes a rotating shaft 2, a rotor 3, and a stator 4.

  The rotor 3 is made of a laminated steel plate and is provided so as to be rotatable integrally with the rotary shaft 2. The rotor 3 includes a columnar rotor yoke 5 and eight rotor magnetic poles 6 that protrude from the circumferential surface of the rotor yoke 5 in the rotational radial direction.

  A shaft insertion hole 7 having a circular cross section is formed through the rotor yoke 5 on the central axis thereof. The rotation shaft 2 is inserted into the shaft insertion hole 7 so as not to be relatively rotatable. In the rotor yoke 5, eight cavities 8 having a substantially sectoral cross section are formed around the shaft insertion hole 7 so as to penetrate in the direction of the central axis (rotation axis) of the rotation shaft 2. Thereby, weight reduction of the rotor yoke 5 is achieved.

  The eight rotor magnetic poles 6 are provided at equiangular intervals, that is, 45 ° intervals around the rotation axis. Each rotor magnetic pole 6 is formed in a substantially rectangular parallelepiped shape extending in the rotation axis direction.

  The stator 4 includes a stator core 9 and a stator coil 10.

  The stator core 9 is made of a laminated steel plate. The stator core 9 has a substantially square cylindrical stator yoke 11 that surrounds the rotor 3 in the rotational circumferential direction, and six stator magnetic poles (teeth) 12 that protrude inside the stator yoke 11.

  The stator yoke 11 has a 180 ° rotationally symmetric shape about the rotation axis.

  Specifically, the stator yoke 11 includes a pair of magnetic pole forming portions 13 formed at two positions 180 degrees apart from each other about the rotation axis, and a direction perpendicular to the rotation axis of the pair of magnetic pole forming portions 13. A pair of connecting portions 14 for connecting both ends are integrally provided. The magnetic pole forming portion 13 is formed in an arc shape in which a cross-sectional shape when cut along a plane orthogonal to the rotational axis bulges in the rotational radial direction. The connecting portion 14 has a substantially U-shaped cross section when cut along a plane orthogonal to the rotation axis.

  The six stator magnetic poles 12 are divided into three parts to form two stator magnetic pole groups 15 and 16. One stator magnetic pole group 15 is formed integrally with one magnetic pole forming portion 13. The three stator magnetic poles 12 constituting the stator magnetic pole group 15 are provided at intervals of 30 ° with the rotation axis as the center. The other stator magnetic pole group 16 is formed integrally with the other magnetic pole forming portion 13. The three stator magnetic poles 12 constituting the stator magnetic pole group 16 are provided at intervals of 30 ° with the rotation axis as the center. Each stator magnetic pole 12 protrudes from the inner surface of the magnetic pole forming portion 13 toward the rotation axis and is formed in a substantially rectangular parallelepiped shape extending in the rotation axis direction.

  The stator coil 10 is concentratedly wound around each stator magnetic pole 12.

  Spaces 17 are formed between the stator magnetic poles 12 at both ends of the stator magnetic pole group 15 and the connecting portions 14. Using this space 17, a first field coil 18 for magnetizing the stator magnetic pole group 15 to the N pole is disposed. The first field coil 18 passes through one space 17, extends to the outer side in the rotational axis direction than the connecting portion 14, bends to the opposite side to the rotating shaft 2 side, and faces the pair of connecting portions 14. Bent to the rotation axis 2 side, extended toward the other space 17, bent in the rotation axis direction, passed through the other space 17, and outside the connecting portion 14 in the rotation axis direction. Extending to the opposite side of the rotating shaft 2 side, bent in the opposing direction of the pair of connecting portions 14, bent toward the rotating shaft 2 side and extended toward one space 17, in the direction of the rotating axis It is wound so that it is bent and passed through one space 17. Thereby, a part of the first field coil 18 can be released from a position facing the stator coil 10 concentratedly wound around the stator magnetic pole 12 of the stator magnetic pole group 15 in the rotation axis direction.

Spaces 19 are formed between the stator magnetic poles 12 at both ends of the stator magnetic pole group 16 and the connecting portions 14. A second field coil 20 for magnetizing the stator magnetic pole group 16 to the S pole is disposed using this space 19. The second field coil 20 is passed through one space 19, extends to the outside in the rotational axis direction than the connecting portion 14, bends to the opposite side of the rotating shaft 2 side, and faces the pair of connecting portions 14. Bent to the rotation axis 2 side, extended toward the other space 19, bent in the rotation axis direction, passed through the other space 19, and outside the connecting portion 14 in the rotation axis direction. Extending to the opposite side of the rotating shaft 2, bent in the opposite direction of the pair of connecting portions 14, bent toward the rotating shaft 2, and extended toward one space 19, in the direction of the rotating axis It is wound so that it is bent and passed through one space 19. Thereby, a part of the second field coil 20 can be released from a position facing the stator coil 10 concentratedly wound around the stator magnetic pole 12 of the stator magnetic pole group 16 in the rotation axis direction.

  When a field current flows through the first field coil 18 and the second field coil 20, the stator magnetic pole group 15 is magnetized to the N pole, and the stator magnetic pole group 16 is magnetized to the S pole. As the rotor 3 rotates, the rotor magnetic pole 6 faces the stator magnetic pole 12 magnetized to the N pole, and another rotor magnetic pole 6 faces the stator magnetic pole 12 magnetized to the S pole. The stator magnetic pole 12 magnetized in the N pole and the stator magnetic pole 12 magnetized in the S pole pass through the rotor 3 / stator yoke 11. As a result, an induced current flows through the stator coil 10 concentratedly wound around the stator magnetic poles 12.

  Since the two stator magnetic pole groups 15 and 16 are separated from each other, the stator yoke 11 can be formed linearly between the stator magnetic pole groups 15 and 16 as shown in FIG. Therefore, compared with the stator 4 in which the stator yoke 11 is formed in an annular shape, the size of the stator 4 in the rotation radial direction can be reduced.

  And since the rotor 3 is not what is called a comb-type rotor 3, it can reduce the size of a rotation radial direction, but can increase the size of a rotation axis direction. Therefore, by reducing the size of the rotor 3 and the stator 4 in the rotational diameter direction and increasing the size in the rotational axis direction thereof, it is possible to ensure the same output as the conventional generator.

  Further, unlike the configuration in which the rotor 3 is provided with a field coil, a slip ring and a brush are not required. Therefore, even if the size of the rotor 3 in the rotation axis direction is increased, the increase in the size can be offset by omitting the space necessary for the arrangement of the slip ring, and the size of the generator 1 as a whole is reduced in the rotation axis direction. It can be prevented from increasing.

  Therefore, when the generator 1 is used in an alternator mounted on an automobile, the output of the generator 1 is reduced while reducing the size of the generator in the radial direction due to the space in the engine room where the alternator is arranged. It can meet the demand to secure.

  Furthermore, since a slip ring and a brush are unnecessary, the number of parts can be reduced. As a result, the cost of the generator 1 can be reduced by reducing the number of parts.

  Further, when the magnetic flux passes between the stator magnetic pole group 15 magnetized at the N pole and the stator magnetic pole group 16 magnetized at the S pole, the magnetic flux passing through the stator yoke 11 is connected to one of the stator yokes 11. Dispersed in the portion 14 and the other connecting portion 14. Therefore, the thickness of the stator yoke 11 can be reduced. As a result, the weight of the stator 4 can be reduced.

  Furthermore, since the rotor 3 is made of a laminated steel plate, the generation of eddy currents on the surface of the rotor 3 can be suppressed. As a result, power generation efficiency can be improved.

  As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  For example, although the case where each stator magnetic pole group 15 and 16 is constituted by three stator magnetic poles 12 is taken as an example, the number of stator magnetic poles 12 constituting each stator magnetic pole group 15 and 16 depends on the number of phases. It should be changed. For example, when the generator 1 is a two-phase AC generator, each of the stator magnetic pole groups 15 and 16 may be constituted by two stator magnetic poles 12.

  Moreover, although the structure provided with the two stator magnetic pole groups 15 and 16 was taken up, three or more stator magnetic pole groups may be provided.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

DESCRIPTION OF SYMBOLS 1 Generator 2 Rotating shaft 3 Rotor 4 Stator 5 Rotor yoke 6 Rotor magnetic pole 9 Stator core 10 Stator coil 11 Stator yoke 15 Stator magnetic pole group 16 Stator magnetic pole group 18 1st field coil 20 2nd field coil

Claims (1)

A generator comprising: a rotary shaft; a rotor provided rotatably with the rotary shaft; and a stator provided around the rotor;
The rotor is formed with a rotor yoke through which the rotating shaft is inserted into a central portion so as not to be relatively rotatable, and a plurality of rotor magnetic poles protruding from the rotor yoke in a rotational radial direction,
The stator includes an annular stator yoke that surrounds the rotor in the circumferential direction of rotation, a stator core on which a plurality of stator magnetic poles projecting inside the stator yoke, and a stator coil that is concentratedly wound around each stator magnetic pole. ,
The plurality of stator magnetic poles comprises a plurality of stator magnetic pole groups at positions separated from each other,
Each stator magnetic pole group is composed of the number of stator magnetic poles corresponding to the number of phases,
The stator magnetic poles constituting each stator magnetic pole group are provided at predetermined intervals,
The plurality of stator magnetic pole groups are separated from each other by the predetermined interval,
A first field coil for magnetizing the stator magnetic pole group to N pole;
A generator comprising: a second field coil for magnetizing the stator magnetic pole group different from the stator magnetic pole group magnetized to the N pole to the S pole.

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