WO2008149865A1

WO2008149865A1 - Rotary machine

Info

Publication number: WO2008149865A1
Application number: PCT/JP2008/060235
Authority: WO
Inventors: Shinya Sano; Eiji Yamada; Kazutaka Tatematsu; Kenji Hiramoto; Kosuke Aiki
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2007-05-31
Filing date: 2008-05-28
Publication date: 2008-12-11
Also published as: JP2008301610A; JP4719183B2

Abstract

A rotor of a rotary machine includes a rotor core formed by connecting a plurality of iron core-divided pieces divided in the circumferential direction. The rotor core is arranged to oppose to a stator in the radial direction orthogonally intersecting the rotation axis direction. Each of the iron core-divided pieces has a slot in which a magnet is arranged. In each of the iron core-divided pieces, the distance between the slot and the connection plane where the iron core-divided pieces adjacent in the circumferential direction are connected is shorter than the distance between the slot and the opposing surface of the stator.

Description

Memorandum book

"Technical field"

The present invention relates to a rotating electrical machine in which a stator and a rotor are arranged opposite to each other in a radial direction perpendicular to the rotation axis direction of the rotor.

"Background Technology"

A related technology of this type of rotating electrical machine is disclosed in Japanese Patent Application Laid-Open No. 2 065 1 6 8 1 2 8. In Japanese Patent Application Laid-Open No. 2 0 0 5-1 6 8 1 2 8, a rotor (rotor core) is constituted by connecting a plurality of core members divided in the circumferential direction to each other, Permanent magnets are embedded in the outer periphery of each core member so as to face the stator. When the magnetic flux flowing in the rotor core in the in-plane direction perpendicular to the rotor rotation axis direction is saturated, the magnetic flux also flows out in the rotation axis direction. When the magnetic flux flowing in the direction of the rotation axis fluctuates, an eddy current flows in the in-plane direction perpendicular to the direction of the rotation axis, causing loss (iron loss) due to this eddy current. In particular, near the magnet in the rotor core, the magnetic flux tends to flow in the direction of the axis of rotation, and loss due to eddy current in the in-plane direction is likely to occur.

For example, as disclosed in Japanese Laid-Open Patent Publication No. 2 0 0 5-1 6 8 1 2 8, an eddy current that flows in an in-plane direction is formed by configuring a rotor core with a plurality of core members divided in the circumferential direction. Since the cross-sectional area (area in the in-plane direction) of the part where the eddy current circulates is reduced by dividing the path, the eddy current in the in-plane direction can be reduced. However, in a rotor in which a magnet is disposed in a slot formed in the rotor core, when the rotor core is divided into a plurality of core members, the stator and the rotor are secured in order to ensure the strength of the rotor. It is necessary to increase the distance between the opposing outer peripheral surface and the slot. However, if the distance between the outer peripheral surface and the slot is increased, the magnetic bridge formed between the outer peripheral surface and the slot also increases, so the magnetic flux of the magnet passes through this bridge. This increases the leakage flux. This leakage magnetic flux reduces the effective magnetic flux to the rotor torque, and the rotor The torque acting on is reduced.

Further, even when the rotor core is constituted by a plurality of core members divided in the circumferential direction, eddy current is generated in-plane between the coupling surface where the core members adjacent in the circumferential direction are combined and the slot (magnet). Flow in the direction. In order to improve the effect of reducing the loss due to the in-plane eddy current, it is desirable to reduce the in-plane eddy current generated between the coupling surface and the slot.

"Disclosure of invention"

An object of the present invention is to provide a rotating electrical machine capable of efficiently reducing a loss that occurs when an eddy current flows in a rotor core in an in-plane direction perpendicular to the rotation axis direction.

One. Furthermore, an object of the present invention is to provide a rotating electrical machine that can efficiently increase the torque acting on the rotor while ensuring the strength of the rotor.

A rotating electrical machine according to the present invention is a rotating electrical machine in which a stator and a rotor are opposed to each other in a radial direction perpendicular to the rotating shaft direction of the rotor, and the rotor is divided into a plurality of circumferentially divided pieces. Each of the core split pieces includes a slot, and a magnet is disposed in the slot. The core split pieces include the rotor core formed by connecting the core split pieces to each other. The gist is that the distance between the slot and the connecting surface where the core split pieces adjacent in the direction are combined is shorter than the distance between the surface facing the stator and the slot.

According to the present invention, it is possible to efficiently reduce a loss that occurs when an eddy current flows in a rotor core in an in-plane direction perpendicular to the rotation axis direction. Furthermore, the torque acting on the rotor can be efficiently increased while ensuring the strength of the rotor. In one aspect of the present invention, in the coupling surface, a distance from a slot positioned forward in the rotor rotation direction from the coupling surface is shorter than a distance from a slot positioned rearward in the rotor rotation direction from the coupling surface. Is preferred.

Further, the rotating electrical machine according to the present invention is a rotating electrical machine in which a stator and a rotor are opposed to each other in a radial direction perpendicular to the rotational axis direction of the rotor, and the rotor is divided in the circumferential direction. Each of the core split pieces is provided with a slot, and a magnet is disposed in the slot, and the circumferential direction In the joint surface where the core split pieces adjacent to each other are combined, the distance from the slot located forward of the rotor rotation direction from the joint surface is the same as the slot located behind the joint surface in the rotor rotational direction. The gist is that it is shorter than the distance.

According to the present invention, it is possible to efficiently reduce a loss that occurs when an eddy current flows in a rotor core in an in-plane direction perpendicular to the rotation axis direction.

In one aspect of the present invention, it is preferable that each iron core split piece is formed with a slot in a substantially V shape, and a magnet is disposed in a slot formed in a substantially V shape. "Brief description of drawings"

FIG. 1 is a diagram showing a schematic configuration of a rotating electrical machine according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of the rotating electrical machine according to the embodiment of the present invention.

FIG. 3 is a diagram showing a schematic configuration of the rotating electrical machine according to the embodiment of the present invention.

FIG. 4 is a diagram for explaining eddy currents flowing in the rotor core in an in-plane direction perpendicular to the rotation axis direction of the rotor in a configuration in which the rotor core is not divided in the circumferential direction.

FIG. 5 is a diagram for explaining an eddy current flowing in the in-plane direction perpendicular to the rotation axis direction of the rotor in the rotor core in the rotating electrical machine according to the embodiment of the present invention.

FIG. 6 is a diagram for explaining the magnetic flux that leaks through the magnetic bridge between the outer peripheral surface of the core split piece and the slot.

FIG. 7 is a diagram illustrating the flow of magnetic flux of the permanent magnet in the rotating electrical machine according to the embodiment of the present invention.

FIG. 8 is a diagram for explaining eddy currents flowing in the rotor core in an in-plane direction perpendicular to the rotation axis direction of the rotor in a configuration in which the rotor core is not divided in the circumferential direction.

FIG. 9 is a diagram showing another schematic configuration of the rotating electrical machine according to the embodiment of the present invention.

“Best Mode for Carrying Out the Invention”

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

1 to 3 are diagrams showing a schematic configuration of a rotating electrical machine according to an embodiment of the present invention. Fig. 1 shows the outline of the internal structure of the stator 1 2 and the rotor 14 viewed from the direction orthogonal to the axis 2 2, and Fig. 2 shows the stator 1 2 viewed from the direction parallel to the axis 2 2 and Inside of rotor 1 4 3 shows a part of the configuration, and FIG. 3 shows a part of the internal configuration of the rotor 14 viewed from the direction parallel to the axis 2 2. However, the configuration of the parts not shown in FIGS. 2 and 3 is the same as that shown. The rotating electrical machine according to the present embodiment includes a stator 12 fixed to a casing (not shown), a rotor 14 disposed radially inside the stator 12 2 and rotatable relative to the stator 12; Is a radial type rotary electric machine. Stator 12 includes a stator core 26 and a plurality of stator coils 28 disposed on stator core 26. In the stator core 26, a plurality of teeth 30 projecting radially inward (rotor 14 side) are arranged at intervals along the circumferential direction of the stator 12. The coil 28 is disposed on these teeth 30.

Rotor 14 includes a rotor core 16, and a plurality of permanent magnets 18 disposed on the outer periphery of rotor core 16. The plurality of permanent magnets 18 are arranged at intervals along the circumferential direction (rotation direction) of the rotor 14. The rotor 14 is provided with an axis 22 along the rotation center axis, and the axis 22 is rotatably supported by the casing. The inner periphery of the stator core 26 (tooth tip 30 a) and the permanent magnet 18 (the outer periphery of the rotor core 16) are in the direction of the rotation axis of the rotor 14 (axis 2 2 in the radial direction perpendicular to the longitudinal direction (hereinafter simply referred to as the rotational axis direction). In the present embodiment, the rotor core 16 is divided into a plurality of core split pieces 36 on the split surface 40. Here, the dividing surface 40 includes a plane that is substantially parallel to the radial direction of the rotor 14 and substantially orthogonal to the circumferential direction of the rotor 14, and the rotor core 1 6 force with respect to the circumferential direction of the rotor 14. It is composed of a plurality of divided iron core divided pieces 36. Each core segment piece 36 can be formed by laminating, for example, thin silicon steel plates (electromagnetic steel plates) in the rotation axis direction.

The rotor core 1 6 is configured by arranging a plurality of core split pieces 3 6 in an annular shape and connecting them together. For example, as shown in FIGS. 2 and 3, as shown in FIGS. 2 and 3, the core split pieces 3 6 are connected to each other on the connecting surface where the core split pieces 3 6 are joined. 3 When joining 6 to 6, it can be fixed by applying pressure in the direction in which both swallow. However, other coupling methods such as screwing or gluing can be used. It should be noted that the joint surface where the core split pieces 36 are joined together when the plurality of core split pieces 36 are joined coincides with the aforementioned split face 40. Slots 42 are formed on the outer periphery of each core segment piece 36, and permanent magnets 18 are inserted into the slots 42. For this reason, the rotor core 16 is also arranged on the surface of the permanent magnet 18 (outside of the permanent magnet 18 in the radial direction of the rotor 14), and the permanent magnet 18 is attached to the rotor core 16. It is buried inside. In the present embodiment, in each core segment piece 36, as shown in FIG. 3, the coupling surface (divided surface 40) and the core segment segments 36 adjacent to each other in the circumferential direction of the rotor 14 are combined. The distance b between the end of the slot 4 2 is set to be shorter than the distance a between the outer peripheral surface 3 6 a opposite to the stator 12 and the end of the slot 4 2 (b <a ). In FIGS. 2 and 3, an example in which the slot 4 2 is formed in a substantially V shape in each of the iron core split pieces 3 6 and is disposed in the slot 4 2 of a substantially magnet-shaped 18 force. An example is shown in which magnets 18 are arranged in a substantially V shape for each pole. However, the arrangement of the permanent magnets 18 is not limited to this example. It is also possible to form a plurality of magnetic poles on each core split piece 36.

In the stator 12, currents are sequentially passed through the stator coils 28, whereby the teeth 30 are sequentially magnetized to form a rotating magnetic field. Then, the magnetic field flux of the permanent magnet 18 of the rotor 14 interacts with this rotating magnetic field, and attraction and repulsion occurs, and the rotor 14 rotates to obtain magnet torque. Further, the rotor core 16 is disposed on the surface of the substantially V-shaped permanent magnet 18, and between the permanent magnets 18 adjacent in the circumferential direction (between the slots 4 2). The portion of the rotor core 16 functions as a salient pole and is attracted to the rotating magnetic field of the stator 12, so that reluctance torque can be obtained in addition to the magnet torque.

As described above, with respect to the rotor core 16, for example, magnetic steel sheets are laminated in the direction of the rotation axis, thereby increasing the magnetic resistance in the direction of the rotation axis and making it difficult for the magnetic flux to flow in the direction of the rotation axis. However, when the magnetic flux flowing through the rotor core 16 in the in-plane direction perpendicular to the rotation axis direction becomes saturated, the magnetic flux also flows out in the rotation axis direction. In particular, when the torque of the rotor 14 is large, the magnetic flux flowing in the rotor core 16 is likely to be saturated, and the magnetic flux easily flows in the direction of the rotation axis. In the configuration in which the rotor core 16 is not divided in the circumferential direction, if the magnetic flux flowing in the rotor core 16 varies in the direction of the rotation axis, for example, as shown in FIG. Eddy current 3 4 flows in the direction As a result, a loss (iron loss) due to this eddy current 34 occurs. In particular, a large amount of magnetic flux flowing in the direction of the rotation axis is generated in the vicinity of the permanent magnet 18 in the rotor core 16, and loss due to the eddy current 34 in the in-plane direction is likely to occur. In addition, when the rotor core 16 is configured by laminating magnetic steel sheets in the direction of the rotation axis, the in-plane direction vortex is low because the specific resistance (electrical resistance) in the in-plane direction perpendicular to the rotation axis direction is low. Current 3 4 tends to increase.

On the other hand, in the present embodiment, the rotor core 16 is configured by connecting a plurality of core segment pieces 36 divided in the circumferential direction by the dividing surface 40 to each other. In other words, the path of the eddy current 3 4 flowing in the in-plane direction through the rotor core 16 is divided by the dividing surface 40, and the cross-sectional area (area in the in-plane direction) of the portion where the eddy current 3 4 circulates is reduced. The Therefore, the eddy current 3 4 flowing in the in-plane direction through the rotor core 16 can be reduced, and the loss due to the in-plane eddy current 3 4 can be reduced.

However, in the rotor 14 in which the permanent magnets 18 are disposed in the slots 4 2 formed in the rotor core 16, the rotor core 16 is divided into a plurality of core split pieces 36. In this case, in order to secure the strength of the rotor 14, it is necessary to increase the distance a between the outer peripheral surface 3 6 a that is the surface facing the stator 1 2 and the slot 4 2. However, if the distance a between the outer peripheral surface 3 6 a and the slot 4 2 is increased, for example, as shown in FIG. 6, the magnetic bridging portion formed between the outer peripheral surface 3 6 a and the slot 4 2 Since 4 3 also increases, the magnetic flux leakage of the permanent magnet 18 due to the passage of the magnetic flux of the permanent magnet 18 through this bridging portion 4 3 tends to increase. Since this leakage magnetic flux 44 is a magnetic flux that hardly contributes to the torque of the rotor 14, the torque acting on the rotor 14 is reduced by the amount of the magnetic flux leaking through the bridge portion 43.

On the other hand, in this embodiment, in each core split piece 36, the distance b between the split surface 40 and the slot 42 is shorter than the distance a between the outer peripheral surface 36a and the slot 42. The Thus, even if the rotor core 16 is divided into a plurality of core split pieces 3 6, the distance a between the outer peripheral surface 3 6 a and the slot 4 2 is increased, and the rotor 14 Sufficient strength can be secured. Further, even if the distance a between the outer peripheral surface 3 6 a and the slot 4 2 is increased by reducing the distance b between the dividing surface 40 and the slot 4 2, as shown in FIG. Leakage flux due to the magnetic flux passing through the bridge part 4 3 can be suppressed, and the effective magnetic flux to the torque of the rotor 1 4 can be increased. Can do. Therefore, the torque acting on the rotor 14 can be increased efficiently.

As described above, according to this embodiment, it is possible to efficiently reduce the loss that occurs when eddy current flows in the rotor core 16 in the in-plane direction perpendicular to the rotation axis direction, and The torque acting on the rotor 14 can be efficiently increased while ensuring the strength of the rotor 14. As a result, high efficiency of the rotating electrical machine can be realized.

In addition, as shown in FIG. 8, in the portion of the rotor core 16 (saliency pole portion) disposed between the permanent magnets 18 adjacent to each other in the circumferential direction (between the slots 4 2), the magnetic flux in the rotation axis direction is The distribution of the eddy current 3 4 in the in-plane direction perpendicular to the rotation axis direction with respect to the center 16a of the salient pole part is due to the fact that the distribution is biased forward in the rotor rotation direction with respect to the center 16a of the salient pole part. It is generated biased forward in the rotor rotation direction. Therefore, in this embodiment, for example, as shown in FIG. 9, each divided surface (coupling surface) 40 is shifted (offset) forward in the rotor rotation direction with respect to the center 16 a of the salient pole portion. It can also be formed. That is, in each divided surface 40, as shown in FIG. 9, the distance b 1 to the slot 4 2a (permanent magnet 18a) located in front of the rotor rotation direction from the divided surface 40 is divided. It can also be set shorter than the distance b 2 with the slot 4 2 b (permanent magnet 18 b) located behind the surface 40 in the rotor rotation direction (bl <b 2). In FIG. 9, one divided plane 40 is shown, but the other divided plane 40 has the same configuration.

According to the configuration shown in FIG. 9, the dividing surface 40 is made to be a salient pole so as to divide the center of the magnetic flux distribution in the rotation axis direction biased forward in the rotor rotation direction with respect to the center 16a of the salient pole portion. The path of the eddy current 3 4 flowing in the in-plane direction between the slots 4 2 a and 4 2 b is efficiently divided by the dividing surface 40 by shifting it forward of the rotor rotation direction with respect to the center 16 a. can do. Therefore, the eddy current 34 flowing in the in-plane direction between the dividing surface 40 and the slots 4 2 a and 4 2 b can be efficiently reduced. As a result, the loss that occurs when eddy current 34 flows in the in-plane direction can be more efficiently reduced.

In this embodiment, for each core split piece 36, a compacted powder obtained by pressing and compacting a powder coated with a film that does not conduct electricity on the surface of a ferromagnetic fine particle such as iron. It can also be formed from a magnetic core material.

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

Claims

The scope of the claims

1. A rotating electrical machine in which a stator and a rotor are opposed to each other in a radial direction perpendicular to the rotational axis direction of the rotor,

The rotor includes a rotor core formed by connecting a plurality of core split pieces divided in the circumferential direction to each other,

Slots are formed in each iron core split piece, and magnets are arranged in the slots.

In each core split piece, the distance between the coupling surface where the circumferentially adjacent core split pieces are combined and the slot is shorter than the distance between the face facing the stator and the slot.

2. The rotating electrical machine according to claim 1,

The rotating electrical machine in which the distance between the coupling surface and the slot located forward of the rotor rotation direction from the coupling surface is shorter than the distance between the slot located behind the coupling surface in the rotor rotation direction.

3. A rotating electrical machine in which a stator and a rotor are opposed to each other in a radial direction perpendicular to the rotational axis direction of the rotor,

In the coupling surface where the core split pieces adjacent to each other in the circumferential direction are combined, the distance between the coupling surface and the slot located in front of the rotor rotation direction from the coupling surface is the slot located behind the coupling surface in the rotor rotation direction. Shorter than the distance between the rotating electrical machine.

4. The rotating electrical machine according to any one of claims 1 to 3,

A rotating electrical machine in which a slot is formed in a substantially V shape in each core segment, and a magnet is disposed in a slot formed in a substantially V shape.