JPH11187594A - Divided stator core and motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a dimensional accuracy in the case of forming a yoke by winding or bending, or forming teeth by winding or bending. SOLUTION: A strip steel sheet 17 is constituted by alternately coupling narrow width parts 18 and wide width parts 19. The each part 18 is formed in a linear shape. And, the each part 19 is formed in an arciate surface state in which an inner periphery 19a and an outer periphery 19b are formed at an annular center of the sheet 17 as a center. And, in the case of forming a yoke of the sheet 17 by winding, only the part 18 is plastically deformed. Thus, a stress due to the plastic deformation is small and a residual stress of the yoke can be reduced, and hence a roundness of the yoke is not impaired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a split stator core in which a teeth portion is connected to an inner peripheral portion of a yoke portion, and a motor having such a split stator core.

[0002]

As a stator core of a motor, for example, there is a split core having a structure in which teeth are connected to an inner peripheral portion of an annular yoke portion. In this case, the yoke portion and the tooth portion are conventionally formed by stacking stamped steel plates. However, in this case, when punching the die-cut steel sheet, there are many parts that are punched and wasted, so that there is a disadvantage that the efficiency of material removal is low.

In order to eliminate such material waste, for example, a strip-shaped steel plate having a predetermined length as shown in FIG. 9 is laminated and bent to form a yoke portion and a tooth portion. As shown in FIG. 10, a method of forming a yoke portion and a tooth portion by a so-called winding process of laminating a strip-shaped steel plate while plastically deforming it in a ring shape is employed.

FIG. 11A shows an example of a strip-shaped steel sheet 1 in a case where a tooth portion is formed by bending. The strip-shaped steel plate 1 is formed by connecting the teeth forming portion 2
It is constituted by being connected by. Then, in a state where a plurality of the strip-shaped steel plates 1 are stacked, the teeth portion is formed by plastically deforming the connecting portion 3 into an annular shape so as to be located on the inner peripheral side.

On the other hand, FIG. 12A shows an example of a strip-shaped steel plate 4 when a yoke portion is formed by bending. The band-shaped steel plate 4 has a fitting recess 5 on one side into which the teeth portion is fitted. Then, in a state in which the plurality of strip-shaped steel plates 4 are stacked, the yoke portion is formed by plastically deforming in an annular manner so that the fitting concave portion 5 is located on the inner peripheral side.

However, when forming either the teeth portion or the yoke portion, as shown in FIGS. 11 (b) and 12 (b), the linear strip-shaped steel plates 1, 4 are plastically deformed in a ring shape. Thus, stress is applied to the entire strip-shaped steel plates 1 and 4. For this reason, in the teeth portion, when plastically deforming, the teeth are partially distorted or elongated to cause errors in each tooth pitch, and the residual stress deteriorates the roundness of the inner peripheral surface of the teeth portion. There was a drawback that dimensional accuracy became unstable. Further, also in the yoke portion, similarly to the above-mentioned teeth portion, there is a disadvantage that dimensional accuracy becomes unstable, for example, roundness is deteriorated due to residual stress. Such a drawback is the same when the teeth portion and the yoke portion are formed by winding.

The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide a split stator core capable of improving dimensional accuracy when a yoke is formed by winding and bending. A second object of the present invention is to provide a split stator core capable of improving dimensional accuracy when forming a tooth portion by winding or bending.
The purpose of the winding process, when forming a split stator core from the yoke and teeth formed by bending,
An object of the present invention is to provide a motor capable of improving dimensional accuracy.

[0008]

According to a first aspect of the present invention, there is provided a split stator core, wherein a strip-shaped steel plate having recesses formed at substantially equal intervals is annularly plastically deformed so that the recesses are on the inner peripheral side. And a yoke portion formed by stacking this annular portion, and a teeth portion connected to a fitting recess formed by the recess on the inner peripheral surface of the yoke portion. A narrow portion that is formed to be narrow, and a substantially arc-shaped wide portion provided between the narrow portions,
The present invention is characterized in that the yoke portion is formed by plastically deforming the narrow portion.

According to such a configuration, the yoke portion can be formed by plastically deforming only the narrow portion of the strip-shaped steel plate. Moreover, since the stress applied by plastically deforming the narrow portion is smaller than in the conventional case where the entire belt-shaped steel plate is plastically deformed in a ring shape, the residual stress of the yoke after plastic deformation can be suppressed as small as possible. As a result, the roundness of the yoke portion can be maintained as much as possible.

In this case, if the narrow portion is formed so as to gradually become narrower from both ends in the circumferential direction toward the central portion,
Stress at the time of plastically deforming the narrow portion can be concentrated on the narrow central portion among the narrow portions.
Invention). Further, the wide portion may have an inner peripheral surface and an outer peripheral surface having an arcuate surface centered on an annular center when the band-shaped steel plate is plastically deformed annularly (the invention of claim 3). .

In the split stator core according to a fourth aspect of the present invention, a large number of T-shaped teeth for forming teeth having an overhang at one end are connected to each other at the tip of the overhang. The belt-shaped steel plate is formed by laminating the annular portion while plastically deforming the annular portion so that the overhang portion is on the inner peripheral side, and the annular portion connected to the outer peripheral portion of the tooth portion. A connecting portion for connecting the adjacent overhanging portions, the connecting portion connecting the adjacent overhanging portions is configured to be narrower than a width dimension of the overhanging portion, and the teeth portion is formed of the strip-shaped steel plate. It is characterized in that the connecting portion is formed by plastic deformation.

According to such a configuration, the teeth portion can be formed by plastically deforming only the connecting portion of the strip-shaped steel plate. At this time, since the connecting portion is narrower than the overhang portion, the stress due to plastic deformation is relatively small. Therefore, unlike the conventional case in which the teeth are formed by plastically deforming the entire belt-shaped steel plate in an annular shape, the residual stress in the teeth can be reduced, and as a result, the roundness of the teeth is reduced as much as possible. Can be suppressed. Further, since the portion connecting the teeth of the teeth portion is narrow, the magnetic flux leaking to the adjacent teeth can be reduced, and as a result, the magnetic characteristics can be improved.

In this case, when the inner peripheral surface of the projecting portion of the strip-shaped steel plate is formed into an arc-shaped surface centered on an annular center when the strip-shaped steel plate is plastically deformed into an annular shape, the inner peripheral portion of the stator is formed. In this case, the distance between the outer peripheral surface of the rotor and the inner peripheral end surface of the teeth portion becomes substantially constant, and the cogging torque can be reduced (the invention of claim 5). Further, it is a good configuration that the outer peripheral surface of the protruding piece portion of the strip-shaped steel plate is formed into an arc-shaped surface having the same curvature as the inner peripheral surface of the overhang portion (claim 6).

According to a seventh aspect of the present invention, there is provided an electric motor comprising a yoke portion according to any one of the first to third aspects and a teeth portion according to the fourth aspect. It is characterized by having a core.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. First, FIG. 5 shows the stator core 11 of the internal rotation type motor as the electric motor according to the present embodiment. In FIG. 5, the stator core 11 is composed of a divided stator core formed by connecting an annular tooth portion 13 to an inner peripheral portion of an annular yoke portion 12. The teeth portion 13 includes, for example, six teeth 14, and has a configuration in which both end portions of a tooth head 14 a of each tooth 14 are connected via a connecting portion 15.

At this time, the connecting portion 15 is configured to be narrower than the width dimension (radial length dimension) of the teeth head 14a. The inner peripheral surface and the outer peripheral surface of the tooth head 14 a are formed in an arc shape around the axis of the rotation shaft of a rotor (not shown) disposed on the inner periphery of the stator core 11. ing. Thus, the inner peripheral surface of the teeth head 14a is configured to be along the outer peripheral surface of the rotor.

Further, six fitting concave portions 16 are formed in the inner peripheral portion of the yoke portion 12, and the outer peripheral end of the teeth 13 is fitted into these fitting concave portions 16. Have been. At this time, the fitting recess 16 is formed such that a portion of the yoke portion 12 where the fitting recess 16 is formed (hereinafter, referred to as a teeth assembly portion 12a) is much narrower than other portions. Is formed.

The yoke portion 12 is formed by winding a strip-shaped steel plate 17 shown in FIG. The strip-shaped steel plate 17 is formed by, for example, pressing a silicon steel plate. Specifically, the strip steel plate 17
Is formed by alternately connecting narrow portions 18 and wide portions 19. The narrow portion 18 has a linear shape.
The wide portion 19 includes an inner peripheral surface 19a and an outer peripheral surface 19a.
b is formed in an arc-shaped surface centered on an annular center O1 (see FIG. 2) when the strip-shaped steel plate 17 is plastically deformed in an annular shape. A portion surrounded by the narrow portion 18 and the wide portions 19 on both sides of the narrow portion 18 forms a concave portion 20 for forming the fitting concave portion 16.

When the yoke portion 12 is formed, as shown in FIG. 2, the strip-shaped steel plate 17 is plastically deformed in a ring shape. At this time, only the narrow portion 18 is plastically deformed to have a shape corresponding to the yoke portion 12.

On the other hand, the teeth portion 13 is formed by a so-called winding process in which the belt-like steel plates 21 shown in FIG. As shown in FIG. 3, the strip-shaped steel plate 21 is formed in a T-shape including a protruding portion 22 for forming the teeth and a projecting portion 23 for forming a teeth head extending on both sides of one end of the protruding portion 22. It is configured by connecting a large number of members 24 via a connecting portion 25. At this time, the connecting portion 25 has a very small length and width. In addition, the overhang portion 23
The inner peripheral surface 23a and the outer peripheral surface 23b are formed in an arc shape corresponding to the shape of the tooth head 14a. That is, the inner peripheral surface 23a and the outer peripheral surface 23b of the projecting portion 23 are formed in an arc shape centered on the annular center O2 (see FIG. 4) when the strip-shaped steel plate 21 is plastically deformed in an annular shape. In addition, both ends of the outer peripheral surface 23b of the overhang portion 23 are configured to be inclined toward the inner peripheral surface 23a, so that both ends of the overhang portion 23 are tapered.

When the teeth 13 are formed, the belt-shaped steel plate 21 is plastically deformed in a ring shape as shown in FIG. At this time, by bending only the connecting portion 25, a shape corresponding to the teeth portion 13 can be obtained.

As described above, according to the present embodiment, when the yoke portion 12 is formed by winding, only the narrow portion 18 of the strip-shaped steel plate 17 is plastically deformed. Therefore, the stress applied to each part of the yoke part 12 by the plastic deformation can be suppressed as much as possible, and the residual stress can be reduced, so that the dimensional accuracy can be improved.
In addition, since the inner peripheral surface 19a and the outer peripheral surface 19b of the wide portion 19 of the strip-shaped steel plate 17 are formed in an arc shape centering on the annular center O1, even if only the narrow portion 18 is plastically deformed, the yoke portion 12 is not deformed. The roundness of the inner peripheral surface and the outer peripheral surface can be maintained.

Further, when the teeth 13 are formed by winding, only the connecting portion 25 of the strip-shaped steel plate 21 which is a narrow portion is plastically deformed. for that reason,
Also in this case, since the stress due to plastic deformation can be suppressed as much as possible, the dimensional accuracy of the teeth 13 can be improved. In addition, since the inner peripheral surface 23a of the projecting portion 23 is formed in an arc shape centering on the annular center O2, even if only the connecting portion 25 is plastically deformed, the teeth head 13 is not deformed.
Since the roundness of the inner peripheral surface of a can be maintained, the cogging torque does not increase. And in this case,
Since the connecting portion 15 (25) is narrower than the width dimension of the teeth head 14a and has a smaller cross-sectional area, the connecting portion 15
The effect that the number of magnetic fluxes leaking to the adjacent teeth 14 via (25) can be reduced can also be obtained.

Next, FIGS. 6 and 7 show a second embodiment of the present invention. Differences from the first embodiment will be described. In the second embodiment, the inner peripheral surface of the teeth assembly portion 12a of the yoke portion 12 is formed into an inclined surface inclined from both ends in the circumferential direction toward the center. Therefore, the center of the teeth assembly 12a is narrower than both ends. As a result, the shape of the fitting recess 16 is changed to the first shape shown in FIG.
It is different from that of the embodiment. When the tips of the teeth 14 are connected to the fitting recesses 16, a substantially triangular gap is formed in the fitting recess 16 in which the tips of the teeth 14 are not fitted. The effect on core performance is negligible.

The teeth assembly 12 of the yoke 12
a corresponding to the above configuration, the steel strip 1
7 has a shape as shown in FIG. That is, the narrow portion 18 of the strip-shaped steel plate 17 extends from both ends in the circumferential direction to the central portion 18.
It is formed so as to become narrower in order toward a. When the yoke portion 12 is formed by plastically deforming the strip-shaped steel plate 17, the central portion 18a of the narrow portion 18 is particularly plastically deformed. Therefore, the stress due to the plastic deformation is concentrated on the central portion 18b of the narrow portion 18. for that reason,
It is possible to reliably prevent stress due to plastic deformation from reaching the entire yoke portion 12.

The present invention is not limited to the embodiment described above and shown in the drawings. For example, the following modifications are possible. In the first and second embodiments, the yoke portion 12 and the teeth portion 13 are formed by winding, but a so-called bending process is performed in which a strip-shaped steel plate having a predetermined length is laminated and the laminated steel plate is plastically deformed in an annular shape. The yoke portion 12 and the teeth portion 13 may be formed by the above method.

The present invention is not limited to the case where both the yoke portion 12 and the teeth portion 13 are formed by winding or bending, but only one of the yoke portion 12 and the teeth portion 13 is formed by winding or bending. The present invention is also applicable to a case where the structure is formed by bending.

When the teeth 13 are formed by bending, for example, as shown in FIG.
The tip surface 32a of the projecting piece 32 is
It is good to make it into the shape of an arc with the same curvature as 3a. In this case, when a large number of strip-shaped steel sheets 31 are die-cut,
The tip surface 32a of the protruding piece part 32 of the
Since the die can be cut so as to be in close contact with the inner peripheral surface 33a of the overhang portion 33, the workability is good. Further, the split stator core of the present invention can be applied not only to a motor but also to a generator.

[0029]

As described above, according to the present invention, a strip-shaped steel plate having recesses formed at substantially equal intervals is plastically deformed in an annular shape so that the recesses are on the inner peripheral side, and the annular portions are laminated. In the split stator core consisting of a yoke portion constituted by: and a tooth portion connected to a fitting recess formed by the recess on the inner peripheral surface of the yoke portion, the belt-shaped steel plate is formed with a recess. The yoke portion is constituted by a narrow portion that becomes narrow and a substantially arc-shaped wide portion provided between the narrow portions, and the yoke portion is formed by plastically deforming the narrow portion. The stress applied to the part can be minimized. Therefore, the residual stress of the entire yoke portion can be reduced, and the dimensional accuracy can be improved.

The present invention also relates to a strip-shaped steel plate formed by connecting a number of T-shaped teeth forming protrusions each having an overhang at one end to each other at the tip of the overhang. The teeth are formed by laminating the annular portion and plastically deforming the annular portion so that the portion is on the inner peripheral side, and an annular yoke portion connected to the outer peripheral portion of the teeth portion is divided and fixed. In the iron core, a connecting portion connecting the adjacent overhanging portions is configured to be narrower than a width dimension of the overhanging portion, and the teeth portion is formed by connecting the connecting portion of the strip-shaped steel plate. Since it is configured by plastic deformation, stress applied to the teeth by plastic deformation can be suppressed as small as possible. Therefore, it is possible to prevent the roundness of the teeth from being impaired as much as possible.

[Brief description of the drawings]

FIG. 1 is a plan view of a strip-shaped steel plate for forming a yoke portion according to a first embodiment of the present invention.

FIG. 2 is a view showing a state in which a yoke portion is formed by plastically deforming a belt-shaped steel plate in an annular shape.

FIG. 3 is a plan view of a strip-shaped steel plate for forming a tooth portion.

FIG. 4 is a diagram showing a state in which a teeth portion is formed by plastically deforming a strip-shaped steel plate.

FIG. 5 is a plan view of a stator core.

FIG. 6 is a view corresponding to FIG. 5, showing a second embodiment of the present invention.

FIG. 7 is a diagram corresponding to FIG. 1;

FIG. 8 is a view showing another embodiment of the present invention and showing a state in which a strip-shaped steel plate for forming a teeth portion is die-cut.

FIG. 9 is a diagram illustrating a bending process.

FIG. 10 is a diagram for explaining winding processing;

11 (a) and FIG. 4 (b) corresponding to FIGS. 3 and 4 showing a conventional example.

12 (a) and FIG. 2 (b).

[Explanation of symbols]

In the drawing, 11 is a stator core (split stator core), 12 is a yoke portion, 13 is a teeth portion, 15 is a connecting portion, 16 is a fitting concave portion, 17 is a strip-shaped steel plate (for forming a yoke portion), and 18 is a width. Narrow portions 21 and 31 are strip-shaped steel plates (for forming teeth portions), 20
Indicates a concave portion.

Claims (7)

[Claims] A yoke portion formed by plastically deforming a strip-shaped steel plate having concave portions formed at substantially equal intervals into an annular shape so that the concave portion is located on the inner peripheral side, and laminating the annular portions; In a split stator core comprising an inner peripheral surface of a yoke portion and a tooth portion connected to a fitting recess formed by the recess, the strip-shaped steel plate has a narrow portion in which a recess is formed and becomes narrower, A split stator core comprising: a substantially arc-shaped wide portion provided between the narrow portions; and the yoke portion is formed by plastically deforming the narrow portion. 2. The split stator core according to claim 1, wherein the narrow portion is formed so as to gradually become narrower from both ends in a circumferential direction toward a central portion. 3. The wide portion has an inner peripheral surface and an outer peripheral surface formed in an arc shape around an annular center when the strip-shaped steel plate is plastically deformed in an annular shape. 2. The split stator core according to 2. 4. A strip-shaped steel plate formed by connecting a number of T-shaped teeth forming protruding portions having a protruding portion at one end to each other at a tip end of the protruding portion, wherein the protruding portion has an inner periphery. In a split stator core comprising a tooth portion formed by laminating the annular portion while plastically deforming the annular portion so as to be on the side, and an annular yoke portion connected to the outer peripheral portion of the tooth portion, A connecting portion connecting the adjacent overhanging portions is configured to be narrower than a width dimension of the overhanging portion, and the teeth portion plastically deforms the connecting portion of the strip-shaped steel plate. A split stator core, comprising: 5. An inner peripheral surface of the overhang portion of the strip-shaped steel plate has an arcuate surface centered on an annular center when the strip-shaped steel plate is plastically deformed in an annular shape. Item 4. The split stator core according to item 4. 6. The split stator core according to claim 5, wherein the outer peripheral surface of the protruding portion of the strip-shaped steel plate has an arc shape having the same curvature as the inner peripheral surface of the overhang portion. 7. A split stator core comprising a yoke portion according to any one of claims 1 to 3 and a teeth portion according to any one of claims 4 to 6. Electric motor.