JP2007082300A - Core and motor equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the loss due to an eddy current by reducing the eddy current generated in teeth in case that a core is composed of a plurality of core segments. <P>SOLUTION: The stator core is composed of the plurality of core segments 32 segmentalized by the cleavage plane 30 at cleavage planes passing inside each tooth 24. The cleavage plane 30 segmentalizes a tooth 24 that it passes, in the direction of array of the tooth 24. The cross section orthogonal to the magnetic flux 36 of the tooth 24 is divided in the circumferential direction of the core by the cleavage plane 30, and the cross section of the tooth 24 where an eddy current 34 circulates decreases, so it can reduce the eddy current 34 generated in the tooth 24. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a core composed of a plurality of core division pieces and an electric motor including the core.

  The related art which comprises a core with a plurality of core division pieces is disclosed in the following Patent Documents 1 to 3. In Patent Documents 1 to 3, a stator core of an electric motor provided with a plurality of teeth is constituted by a plurality of core division pieces divided for each tooth unit. As described above, since the core is divided into a plurality of core divided pieces for each tooth unit, the apparatus for forming the core (core divided piece) can be downsized, and the production efficiency of the core can be improved. Can be planned.

Japanese Patent No. 3430521 Japanese Patent No. 3629071 JP 2004-104917 A

  Eddy currents are generated in the teeth due to fluctuations in the amount of magnetic flux passing through the teeth, and the loss increases as the eddy current increases. As in Patent Documents 1 to 3, in order to reduce the size of the device for forming the core, when the core is constituted by a plurality of core divided pieces divided for each tooth unit, the teeth that eddy current circulates are disconnected. Increases area. Therefore, there is a problem that eddy current generated in the teeth increases due to fluctuations in the amount of magnetic flux, and loss due to this eddy current increases.

  An object of this invention is to reduce the loss by an eddy current by reducing the eddy current which generate | occur | produces in a tooth | gear, when a core is comprised with a several core division | segmentation piece.

  The core according to the present invention and the electric motor including the same employ the following means in order to achieve the above-described object.

  An electric motor according to the present invention is an electric motor that includes a core that includes a plurality of teeth that are erected from a yoke and that are arranged at intervals in a predetermined direction and that are provided with a coil. In summary, the divided surface includes a surface that passes through the inside of the teeth and divides the teeth in a direction substantially coinciding with the arrangement direction of the teeth.

  According to the present invention, the cross-sectional area of the tooth where the cross section orthogonal to the magnetic flux of the teeth is divided in the direction substantially coincident with the direction of arrangement of the teeth and the path of the eddy current circulating inside the teeth is divided to circulate the eddy current Decrease. Therefore, when the core is constituted by a plurality of core divided pieces, eddy current generated in the teeth can be reduced, and loss due to eddy current can be reduced.

  In one aspect of the present invention, it is preferable that the dividing surface further includes a surface that passes through the inside of the teeth and divides the teeth in a direction substantially orthogonal to the arrangement direction and the standing direction of the teeth. According to this aspect, since the cross-sectional area of the tooth through which the eddy current circulates can be further reduced, the eddy current generated in the tooth can be further reduced.

  In one aspect of the present invention, it is preferable that the surface that divides the teeth in a direction substantially coinciding with the arrangement direction of the teeth is a surface that divides the teeth substantially equally.

  In one aspect of the present invention, each of the plurality of core division pieces is preferably formed of a dust core material.

  In one aspect of the present invention, it is preferable that the electric motor is a radial type electric motor in which the axial direction of the rotating shaft and the standing direction of the teeth are orthogonal to each other. In one embodiment of the present invention, it is preferable that the electric motor is an axial type electric motor in which the axial direction of the rotating shaft is parallel to the standing direction of the teeth.

  The core according to the present invention is a core that includes a plurality of teeth that are erected from a yoke and that are arranged at intervals in a predetermined direction and that are provided with a coil. It is comprised by the core division | segmentation piece, and it makes it a summary that the said division | segmentation surface contains the surface which divides | segments this teeth in the direction which substantially passes in the inside of a tooth and the teeth are arranged.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

“Embodiment 1”
1 and 2 are diagrams schematically illustrating a configuration of an electric motor including a core according to Embodiment 1 of the present invention, and show a case where the present invention is applied to a stator core 12 of the electric motor. FIG. 1 shows an outline of the internal configuration of the entire motor, and FIG. 2 shows an outline of the configuration of the stator core 12. The electric motor according to the first embodiment is a radial electric motor in which a stator including the stator core 12 and the rotor 14 are opposed to each other in a direction orthogonal to the axial direction of the rotating shaft, that is, in the radial direction.

  Rotor 14 includes a rotor core 16 provided as a field core and a plurality of permanent magnets 20 arranged in the circumferential direction of the rotor. The stator core 12 provided as an armature core includes a substantially ring-shaped yoke 22 and a plurality of teeth 24 erected from the yoke 22 toward the rotor 14 and arranged at intervals in the core circumferential direction. Including. Here, the standing direction of each tooth 24 from the yoke 22 coincides with the radial direction of the electric motor, and is a direction orthogonal to the axial direction of the rotating shaft. Each tooth 24 is provided with a coil 26, and a magnetic pole is formed by passing a current therethrough. By sequentially passing current through the coil 26, the teeth 24 are sequentially magnetized to form a rotating magnetic field. Then, the permanent magnet 20 of the rotor 14 interacts with this rotating magnetic field, so that attraction and repulsion occurs, the rotor 14 rotates and power can be obtained. Note that the coil 26 provided in the tooth 24 may be either concentrated winding or distributed winding.

  In the present embodiment, the stator core 12 is composed of a plurality of core division pieces 32 divided by a division surface 30 passing through the inside of each tooth 24 as shown in FIGS. Here, FIG. 3 shows an outline of the configuration of the core dividing piece 32. The dividing surface 30 that passes through the inside of each tooth 24 here is a surface that divides the tooth 24 through which the tooth 24 passes in a direction (or substantially the same direction) that coincides with the arrangement direction (core circumferential direction) of the teeth 24. As a more specific example, the dividing surface 30 is substantially parallel to the standing direction (direction of magnetic flux passing through the teeth 24) of the teeth 24 divided by the dividing surface 30 and substantially parallel to the arrangement direction (core circumferential direction) of the teeth 24. It is an orthogonal plane. 2 and 3, an example in which a split surface 30 is formed at a central position in the core circumferential direction of each tooth 24, and each tooth 24 is divided into two equal parts (or almost equal parts) in the core peripheral direction. Show.

  Each of the plurality of core division pieces 32 is formed of a powder magnetic core material. The powder magnetic core material is a material obtained by pressing and compacting a powder coated with a film that does not conduct electricity on the surface of fine particles of a ferromagnetic material such as iron. By molding each core segment 32 using this dust core material, eddy currents generated in the stator core 12 are suppressed.

  The stator core 12 is configured by combining a plurality of core division pieces 32. In that case, for example, the plurality of core divided pieces 32 can be coupled by the hook-shaped member 42 covering the outer periphery of the stator core 12 (each core divided piece 32). However, it is also possible to use other coupling methods such as screwing or adhesion. When the plurality of core divided pieces 32 are joined, the joining surface where the core divided pieces 32 are combined with each other coincides with the aforementioned divided surface 30.

  Here, as a comparison object with the present embodiment, as shown in FIG. 4, consider a case where the stator core is divided into a plurality of core division pieces for each unit of teeth. In that case, as shown in FIG. 4, the eddy current 34 accompanying the magnetic flux fluctuation flows over almost the entire cross section (cross section perpendicular to the standing direction) perpendicular to the magnetic flux 36 of the tooth 24, and the eddy current 34 circulates. The cross-sectional area of the teeth 24 to be increased increases. Therefore, the eddy current 34 generated in the tooth 24 increases, and the loss (iron loss) due to the eddy current 34 also increases. Further, when the stator core is divided for each tooth unit, as shown in FIG. 4, a divided surface 29 for dividing the stator core is formed on the yoke 22, and the divided surface 29 divides the yoke 22 and passes through the yoke 22. Is orthogonal to 36. For this reason, the magnetic resistance also increases.

  On the other hand, in the present embodiment, when the stator core 12 is divided into a plurality of core division pieces 32 by the division surface 30, each tooth 24 is divided in the core circumferential direction by the division surface 30 passing through the inside of each tooth 24. Is done. As a result of the division of the teeth 24, as shown in FIG. 3, the cross section perpendicular to the magnetic flux 36 of the teeth 24 (the cross section perpendicular to the standing direction) is divided with respect to the circumferential direction of the core. The path is divided and the cross-sectional area of the tooth 24 through which the eddy current 34 circulates is reduced. Therefore, the eddy current 34 generated in the tooth 24 can be reduced, and the loss (iron loss) due to the eddy current 34 can be reduced. For example, when each tooth 24 is divided into two equal parts with respect to the circumferential direction of the core by the dividing surface 30, the cross-sectional area of each tooth 24 through which the eddy current 34 circulates is halved, and loss due to the eddy current 34 (iron loss) ) Is reduced about 0.7 times. In the present embodiment, the eddy current 34 is also reduced by molding each core divided piece 32 with a powder magnetic core material. However, each tooth 24 is arranged in the core circumferential direction by a divided surface 30 passing through the inside of each tooth 24. Can be further improved in the effect of reducing the eddy current 34. Furthermore, in this embodiment, as shown in FIG. 3, the dividing surface 30 is parallel to the direction of the magnetic flux 36 passing through the teeth 24, so that the magnetic resistance is not increased.

  Moreover, in this embodiment, since the stator core 12 is divided | segmented into the several core division piece 32 regarding the core circumferential direction by the division surface 30 which passes the inside of each teeth 24, each core division piece 32 can be reduced in size. In addition, the apparatus for forming the stator core 12 (core divided piece 32) can be downsized. Therefore, the manufacturing efficiency of the stator core 12 can be improved.

  In the above description of the present embodiment, each tooth 24 is divided into approximately two equal parts in the core circumferential direction by the dividing surface 30 passing through the inside of each tooth 24. However, it is also possible to form the dividing surface 30 so that each tooth 24 is divided into three or more equal parts in the circumferential direction of the core. Furthermore, the dividing surface 30 does not necessarily divide the teeth 24 equally.

  Further, in the present embodiment, the stator core 12 can be divided not only with respect to the core circumferential direction but also with respect to a direction orthogonal to the core circumferential direction and the core radial direction, that is, with respect to the axial direction of the rotary shaft of the radial electric motor. In that case, as shown in FIG. 5, the dividing surface 31 that divides the stator core 12 in the axial direction of the rotating shaft passes through the inside of each tooth 24, and each tooth 24 is orthogonal to the arrangement direction and the standing direction of the teeth 24. It is a surface that is divided in a direction (or a substantially orthogonal direction). Here, FIG. 5 shows an outline of the configuration of the core divided piece 32 divided by the dividing surfaces 30 and 31. As a more specific example, the dividing surface 31 is a plane orthogonal to the axial direction of the rotation axis. FIG. 5 shows an example in which a split surface 31 is formed at the center position of the stator core 12 in the axial direction of the rotating shaft, and each tooth 24 is divided into two equal parts in the axial direction of the rotating shaft. However, it is also possible to form the dividing surface 31 so that each tooth 24 is divided into three or more equal parts with respect to the axial direction of the rotating shaft. Further, the dividing surface 31 is not necessarily required to equally divide the teeth 24.

  As described above, the teeth 24 are not only divided in the core circumferential direction by the dividing surface 30, but also divided in the axial direction of the rotation axis by the dividing surface 31, thereby reducing the cross-sectional area of the tooth 24 through which the eddy current 34 circulates. It can be further reduced. Therefore, the eddy current 34 generated in the tooth 24 can be further reduced, and the loss reduction effect due to the eddy current 34 can be further improved. The relationship between the division number N of the teeth 24 and the loss reduction ratio K can be approximately expressed by the following equation (1).

K = 1 / N ^0.5 (1)

  Moreover, in the above description of this embodiment, each core division | segmentation piece 32 shall be comprised with a powder magnetic core material. However, each core division piece 32 can also be constituted by laminating electromagnetic steel plates (silicon steel plates) in the axial direction of the rotation axis (direction orthogonal to the arrangement direction of the teeth 24 and the standing direction).

“Embodiment 2”
FIGS. 6-8 is a figure which shows the outline of a structure of the electric motor provided with the core which concerns on Embodiment 2 of this invention, and shows the case where this invention is applied to the stator core 62 of an electric motor. 6 shows an outline of the internal configuration of the entire motor, FIG. 7 shows an outline of the configuration of the stator including the stator core 62, and FIG. 8 shows an outline of the configuration of the stator core 62. The electric motor according to the second embodiment is an axial type electric motor in which a stator including the stator core 62 and the rotor 64 face each other in a direction parallel to the axial direction of the rotation shaft.

  The rotor 64 has a substantially disc shape, and includes a rotor core provided as a field core and a plurality of permanent magnets arranged in the circumferential direction of the rotor, as in the first embodiment. A stator core 62 provided as an armature core includes a substantially ring-shaped yoke 72 and a plurality of teeth 74 standing from the yoke 72 toward the rotor 64 and arranged at intervals in the core circumferential direction. Including. Here, the standing direction of each tooth 74 from the yoke 72 is a direction parallel to the axial direction of the rotating shaft of the electric motor. Each tooth 74 is provided with a coil 76, and a magnetic pole is formed by passing an electric current therethrough. As in the first embodiment, the teeth 74 are sequentially magnetized by sequentially passing current through the coil 76, and a rotating magnetic field is formed. Then, the permanent magnet of the rotor 64 interacts with this rotating magnetic field, and an attractive and repulsive action occurs, and the rotor 64 rotates to obtain power. Note that the coil 76 provided in the tooth 74 may be either concentrated winding or distributed winding.

  In the present embodiment, the stator core 62 is constituted by a plurality of core division pieces 82 divided by a division surface 80 passing through the inside of each tooth 74 as shown in FIGS. Here, FIG. 9 shows a schematic configuration of the core dividing piece 82. Here, the dividing surface 80 that passes through the inside of each tooth 74 is a surface that divides the tooth 74 through which the tooth 74 passes in a direction (or substantially the same direction) that coincides with the arrangement direction (core circumferential direction) of the teeth 74. As a more specific example, the dividing surface 80 is substantially parallel to the standing direction (direction of magnetic flux passing through the teeth 74) of the teeth 74 divided by the dividing surface 80 and substantially parallel to the arrangement direction (core circumferential direction) of the teeth 74. It is an orthogonal plane. 8 and 9, an example in which a split surface 80 is formed at the center position of each tooth 74 in the core circumferential direction, and each tooth 74 is divided into two equal parts (or approximately two equal parts) in the core circumferential direction. Show. However, it is also possible to form the dividing surface 80 so that each tooth 74 is divided into three or more equal parts in the core circumferential direction. Further, the dividing surface 80 is not necessarily required to equally divide the teeth 74.

  Each of the plurality of core division pieces 82 is formed of a powder magnetic core material. And the stator core 62 is comprised by combining the several core division | segmentation piece 82. FIG. In that case, the several core division | segmentation piece 82 can be couple | bonded by the collar-shaped member 92 which covers the outer periphery of the stator core 62 (each core division piece 82), for example. When the plurality of core divided pieces 82 are combined, the connecting surface where the core divided pieces 82 are combined with each other coincides with the aforementioned divided surface 80.

  Also in the present embodiment described above, the cross section perpendicular to the magnetic flux of the tooth 74 (the cross section perpendicular to the standing direction) is divided with respect to the circumferential direction of the core, the eddy current path circulating inside the tooth 74 is divided, and the eddy current is generated. The cross-sectional area of the circulating teeth 74 is reduced. Therefore, eddy current generated in the teeth 74 can be reduced, and loss (iron loss) due to eddy current can be reduced. Furthermore, since the dividing surface 80 is parallel to the direction of the magnetic flux passing through the teeth 74, the magnetic resistance is not increased. Also in this embodiment, each core division piece 82 can be reduced in size, and the apparatus for forming the stator core 62 (core division piece 82) can be reduced in size.

  Also in this embodiment, the stator core 62 can be divided not only in the core circumferential direction but also in the core radial direction. In that case, the dividing surface that divides the stator core 62 in the core radial direction passes through the inside of each tooth 74 and divides each tooth 74 in a direction (or substantially orthogonal direction) perpendicular to the arrangement direction and the standing direction of the teeth 74. It becomes the surface to do. Thus, by dividing each tooth 74 not only in the core circumferential direction by the dividing surface but also in the core radial direction, the cross-sectional area of the tooth 74 in which the eddy current circulates can be further reduced.

  Also in this embodiment, each core split piece 82 can also be configured by laminating electromagnetic steel plates (silicon steel plates) in the core radial direction (the direction orthogonal to the arrangement direction of the teeth 74 and the standing direction). .

  In each of the above embodiments, the case where the present invention is applied to a stator core of an electric motor has been described. However, the present invention can also be applied to a rotor core of an electric motor.

  In each of the above embodiments, the case where the present invention is applied to a radial type electric motor or an axial type electric motor has been described, but the present invention can also be applied to a linear electric motor.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course.

It is a figure which shows the outline of the internal structure of the electric motor which concerns on Embodiment 1 of this invention. It is a figure which shows the outline of a structure of the stator core in the electric motor which concerns on Embodiment 1 of this invention. It is a figure which shows the outline of a structure of the core division | segmentation piece in the electric motor which concerns on Embodiment 1 of this invention. It is a figure which shows the outline of a structure of the core division | segmentation piece at the time of dividing | segmenting the stator core of an electric motor for every teeth unit. It is a figure which shows the outline of the other structure of the core division | segmentation piece in the electric motor which concerns on Embodiment 1 of this invention. It is a figure which shows the outline of the internal structure of the electric motor which concerns on Embodiment 2 of this invention. It is a figure which shows the outline of a structure of the stator in the electric motor which concerns on Embodiment 2 of this invention. It is a figure which shows the outline of a structure of the stator core in the electric motor which concerns on Embodiment 2 of this invention. It is a figure which shows the outline of a structure of the core division | segmentation piece in the electric motor which concerns on Embodiment 2 of this invention.

Explanation of symbols

  12, 62 Stator core, 14, 64 Rotor, 22, 72 Yoke, 24, 74 Teeth, 26, 76 Coil, 30, 31, 80 Divided surface, 32, 82 Core divided piece, 42, 92 A bowl-shaped member.

Claims (7)

An electric motor comprising a core including a plurality of teeth standing from a yoke and arranged at intervals in a predetermined direction and provided with a coil,
The core is composed of a plurality of core division pieces divided by a division surface,
The electric motor according to claim 1, wherein the dividing surface includes a surface that passes through the inside of the teeth and divides the teeth in a direction substantially coinciding with the arrangement direction of the teeth. The electric motor according to claim 1,
The electric motor according to claim 1, wherein the dividing surface further includes a surface that passes through the inside of the teeth and divides the teeth in a direction substantially perpendicular to the arrangement direction and the standing direction of the teeth. The electric motor according to claim 1 or 2,
The electric motor according to claim 1, wherein the surface that divides the teeth in a direction substantially coinciding with the arrangement direction of the teeth is a surface that substantially divides the teeth. The electric motor according to any one of claims 1 to 3,
Each of the plurality of core division pieces is formed of a powder magnetic core material. The electric motor according to any one of claims 1 to 4,
The electric motor is a radial type electric motor in which the axial direction of the rotating shaft and the standing direction of the teeth are orthogonal to each other. The electric motor according to any one of claims 1 to 4,
The electric motor is an axial type electric motor in which the axial direction of the rotating shaft and the standing direction of the teeth are parallel to each other. A core including a plurality of teeth standing from a yoke and arranged at intervals in a predetermined direction and provided with a coil;
The core is composed of a plurality of core division pieces divided by a division surface,
The core is characterized in that the dividing surface includes a surface that passes through the inside of the teeth and divides the teeth in a direction substantially coinciding with the arrangement direction of the teeth.

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