JP2023017231A - stator - Google Patents

Abstract

To provide a stator in which eddy-current loss that occurs in a rectangular coil can be reduced.SOLUTION: A stator 1 comprises stator cores 10 having a plurality of slots 12 each open in an inner peripheral surface 11 and a plurality of teeth 13 each formed between the slots 12 adjacent to each other, and rectangular coils 20 wound around the teeth 13 respectively. The rectangular coil 20 has a penetration hole portion 26 penetrating from an inner surface 27 of the rectangular coil 20 opposing the inner peripheral surface 11 up to an outer surface 28 of the rectangular coil 20 opposing an outer peripheral surface 18 of the stator core 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to stators.

Patent Literature 1 discloses a stator as an example of an armature of an electric motor. The stator of Patent Document 1 includes a stator core having a plurality of slots opening on the inner peripheral surface and a plurality of teeth formed between the slots adjacent to each other; a circular coil;

JP-A-62-203527

By the way, the electric motor is required to be small and have a large output. Therefore, it is important to improve the energy efficiency of electric motors. As one of the techniques for increasing the energy efficiency of electric motors, it has been known to improve the space factor of coils. The space factor is improved. However, in a motor using rectangular coils, since the rectangular coils have a large surface area, eddy currents are generated when magnetic flux from a permanent magnet or the like reaches the rectangular coils when the rotor rotates. As a result, eddy current loss increases, which may reduce the energy efficiency of the motor.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a stator capable of reducing eddy current loss generated in rectangular coils.

One aspect of the present invention is a stator core having a plurality of slots opening on an inner peripheral surface and a plurality of teeth formed between adjacent slots, and a rectangular coil wound around each of the teeth. and, the flat coil is a stator having a through-hole penetrating from the inner surface of the flat coil facing the inner peripheral surface to the outer surface of the flat coil facing the outer peripheral surface of the stator core.

According to this configuration, the stator core has a plurality of slots opening on the inner peripheral surface, a plurality of teeth formed between the adjacent slots, and flat coils wound around the teeth. In the stator provided, the rectangular coil has a through hole penetrating from the inner surface of the rectangular coil facing the inner peripheral surface to the outer surface of the rectangular coil facing the outer peripheral surface of the stator core. For this reason, from the inner surface to the outer surface of the rectangular coil, the current loop of the eddy current caused by the leakage magnetic flux is divided by the through hole, making it difficult to generate a current loop of a large eddy current. , the eddy current loss generated in the rectangular coil can be reduced.

In this case, the rectangular coil may have a through hole in the winding closest to the inner peripheral surface.

According to this configuration, since the rectangular coil has the through-hole portion in the winding closest to the inner peripheral surface where eddy currents due to leakage magnetic flux are likely to occur, the eddy current loss generated in the rectangular coil is more effectively reduced. can do.

Also, in a cross-sectional view perpendicular to the rotation axis of the rotor surrounding the stator iron core, the approach side on the side where the rotor rotating on the teeth approaches and the separation on the side on which the rotor rotating on the teeth leaves. When the tooth is divided into two sides, the through hole portion may be provided on the approach side portion.

According to this configuration, in a cross-sectional view perpendicular to the rotation axis of the rotor surrounding the stator iron core, the approaching side portion on the side where the rotor rotating to the teeth approaches and the rotor rotating to the teeth are detached. When the teeth are divided into two parts, one on the detached side and the other on the approach side, since the through holes are provided on the approach side, magnetic flux saturation is likely to occur at the tip of the tooth. Current loss can be reduced more effectively.

Further, the rectangular coil may have through holes in the coil sides accommodated in the slots, and may not have through holes in the coil ends wound around the teeth outside the slot.

According to this configuration, the rectangular coil has a through hole portion in the coil side accommodated in the slot where the problem of eddy current loss due to leakage magnetic flux occurs, and the rectangular coil has a through hole portion outside the slot where the problem of eddy current loss due to leakage magnetic flux does not occur. Since the ends of the coils wound around the teeth do not have through holes, the eddy current loss generated in the rectangular coil can be reduced simply by providing through holes where necessary.

Further, the rectangular coil may include a reduced width portion in which the width of the inner peripheral surface in the circumferential direction decreases with winding closer to the inner peripheral surface.

According to this configuration, since the rectangular coil includes a reduced width portion in which the width of the inner peripheral surface in the circumferential direction decreases as the winding nearer to the inner peripheral surface is wound, The eddy current loss generated in the rectangular coil can be reduced by reducing the interlinking area of the magnetic flux by winding.

In this case, in the width reduction portion, the radial thickness of the inner peripheral surface may increase as the circumferential width of the inner peripheral surface decreases.

According to this configuration, in the reduced-width portion, as the width of the inner peripheral surface in the circumferential direction decreases, the thickness of the inner peripheral surface in the radial direction increases. , the variation in the resistance value of each part of the rectangular coil can be reduced.

According to the stator of one aspect of the present invention, it is possible to reduce the eddy current loss generated in the rectangular coil.

1 is a cross-sectional view of a rotor of an electric motor having a stator according to one embodiment, perpendicular to the rotation axis; FIG. 2 is a cross-sectional view taken by γ-rays in FIG. 1 ; 1 is a cross-sectional view perpendicular to the rotation axis of a rotor showing magnetic flux in the vicinity of one tooth of a stator and a rectangular coil wound around the one tooth according to one embodiment; It is a cross-sectional view of a rotor of an electric motor having a conventional stator perpendicular to the rotation axis. FIG. 5 is a cross-sectional view along the β line of FIG. 4; (A) and (B) are diagrams showing modifications of the through hole.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1 , an electric motor 80 having a stator 1 according to one embodiment of the present invention includes a rotor 50 that rotates around a rotation axis 51 while being surrounded by the stator 1 . The electric motor 80 is applied, for example, to the field of aerospace, and is applied, for example, to power a fuel pump. Motor 80 may be a DC motor or an AC motor. If the motor 80 is a DC motor, the motor 80 may be, for example, an electromagnetic field commutator motor. If the motor 80 is an AC motor, the motor 80 may be, for example, an AC motor and an AC commutator motor.

The stator 1 includes a stator core 10 and rectangular coils 20 . Stator core 10 has a plurality of slots 12 opening to inner peripheral surface 11 of stator 1 and a plurality of teeth 13 formed between adjacent slots 12 . In the following description and illustrations, the circumferential direction Dc of the inner peripheral surface 11 and the radial direction Dr of the inner peripheral surface 11 are used as a reference. The slot 12 is of a semi-open slot type. The semi-open slot type is a slot in which the width in the circumferential direction Dc of the opening of the slot 12 that opens to the inner peripheral surface 11 is narrower than the width in the circumferential direction Dc of the portion where the rectangular coil 20 is mounted. The slots 12 refer to spaces (areas) sandwiched between side surfaces of the teeth 13 adjacent to each other in the circumferential direction Dc.

Each of teeth 13 is fixed to back yoke 14 . In this embodiment, the stator core 10 is a split core in consideration of manufacturability. An outer peripheral surface 18 of the stator core 10 outside the back yoke 14 is surrounded by a case (not shown). The width in the circumferential direction Dc of the tip portions of the teeth 13 in the vicinity of the inner peripheral surface 11 is wider than the width in the circumferential direction Dc of the end portions of the teeth 13 in the vicinity of the back yoke 14 . In this embodiment, an existing stator core 10 can be applied. In a cross-sectional view of the rotor 50 perpendicular to the rotation axis 51, the slots 12 and the teeth 13 are symmetrical with respect to a line parallel to the radial direction Dr.

In a cross-sectional view of the rotor 50 surrounded by the stator core 10 perpendicular to the rotating shaft 51, the approaching side portion 16 on the side where the rotor 50 rotating to the teeth 13 approaches and the rotor 50 rotating to the teeth 13 are shown. The tooth 13 can be divided into two parts, the detachment side portion 17 on the side from which the teeth 13 are detached. The side where the rotating rotor 50 approaches the teeth 13 is the side opposite to the rotational direction DR of the rotor 50 . The side from which the rotor 50 rotating on the teeth 13 leaves is the side in the rotation direction DR of the rotor 50 . Dividing into two means, for example, dividing the rotor 50 into two on a plane including the rotation axis 51 . It should be noted that the halving means that it is possible to assume that the teeth 13 are divided into two, the approaching side portion 16 and the detaching side portion 17, and the approaching side portion 16 and the detaching side portion 17, which are the teeth 13 divided into two. It does not need to be constructed from separate members.

As shown in FIG. 1 , the rectangular coil 20 is wound around each of the teeth 13 . The flat coil 20 is a wire having a quadrilateral shape when viewed in cross section perpendicular to the winding direction of the flat coil 20 . In other words, the rectangular coil 20 is composed of a plurality of plate members 20a laminated along the radial direction Dr and having a quadrilateral cross-sectional shape. Each plate member 20a of the rectangular coil 20 has a rectangular annular shape when viewed from the radial direction Dr. Each plate member 20 a of the rectangular coil 20 has an inner side surface 27 facing the inner peripheral surface 11 and an outer side surface 28 facing the outer peripheral surface 18 of the stator core 10 . In other words, the inner surface 27 is the inner peripheral surface 11 side surface of each of the plate members 20 a that constitute the rectangular coil 20 . The outer surface 28 is the surface of each of the plate members 20 a that constitute the rectangular coil 20 on the side of the outer peripheral surface 18 .

As shown in FIGS. 1 and 2, each plate member 20a of the rectangular coil 20 is composed of coil sides 20s and coil ends 20e. A coil side 20 s is a side portion of the plate member 20 a of the rectangular coil 20 . The coil sides 20s are portions of the plate material 20a of the rectangular coil 20 on both sides of the teeth 13 in the circumferential direction Dc. The coil side 20 s is a portion of the plate member 20 a of the rectangular coil 20 that is located in the slot 12 . That is, the coil side 20s is accommodated in the slot 12. As shown in FIG.

The coil side 20s has a quadrangular shape when viewed from the radial direction Dr. One end of the coil side 20 s in the direction parallel to the rotating shaft 51 coincides with one end of the tooth 13 in the direction parallel to the rotating shaft 51 . The other end of the coil side 20 s in the direction parallel to the rotating shaft 51 coincides with the other end of the teeth 13 in the direction parallel to the rotating shaft 51 .

The coil ends 20 e are end portions of the plate member 20 a of the rectangular coil 20 . The coil ends 20 e are portions of the plate member 20 a of the rectangular coil 20 other than the coil sides 20 s and are portions on both sides of the teeth 13 in the direction parallel to the rotation shaft 51 . That is, the coil ends 20e are positioned outside the slot 12. As shown in FIG.

Being located in the slot 12 and being accommodated in the slot 12 means that the part to be arranged exists in a space (region) sandwiched between side surfaces of the teeth 13 adjacent to each other in the circumferential direction Dc. On the other hand, "located outside the slot 12" and "arranged outside the slot 12" means that the part to be arranged does not exist in the space (area) sandwiched between the side surfaces of the teeth 13 adjacent to each other in the circumferential direction Dc. means In other words, it means that the parts to be arranged are present in a direction away from the end surfaces 13 a and 13 b orthogonal to the axis parallel to the rotation shaft 51 in the teeth 13 .

The flat coil 20 has a through hole portion 26 penetrating from an inner surface 27 of the flat coil 20 to an outer surface 28 of the flat coil 20 facing the outer peripheral surface 18 of the stator core 10 . The rectangular coil 20 has a through hole portion 26 in the winding closest to the inner peripheral surface 11 . That is, the through-hole portion 26 is formed in the plate member 20 a at the end portion of the flat coil 20 on the inner peripheral surface 11 side among the plurality of plate members 20 a of the flat coil 20 .

Also, the through hole portion 26 is provided in the approach side portion 16 . The through hole portion 26 is provided in the coil side 20s on the approach side portion 16 side of the plate member 20a of the rectangular coil 20. As shown in FIG. Therefore, as shown in FIG. 1, in a cross-sectional view of the rotor 50 orthogonal to the rotating shaft 51, the slots 12 and the teeth 13 are symmetrical with respect to a line parallel to the radial direction Dr. is asymmetric with respect to a line parallel to the radial direction Dr. Further, as shown in FIG. 2, the rectangular coil 20 has a through-hole portion 26 in the coil side 20s accommodated in the slot 12, and a through-hole portion in the coil end 20e wound around the teeth 13 outside the slot 12. It does not have the part 26 .

The through-hole portion 26 has a plurality of slits 26a extending in a direction parallel to the rotating shaft 51. As shown in FIG. Each slit 26 a extends over the entire coil side 20 s in the direction parallel to the rotation axis 51 . That is, one end of the slit 26a in the direction parallel to the rotating shaft 51 coincides with one end of the tooth 13 in the direction parallel to the rotating shaft 51. As shown in FIG. The other end of the slit 26 a in the direction parallel to the rotating shaft 51 coincides with the other end of the teeth 13 in the direction parallel to the rotating shaft 51 .

At least one of one end and the other end of the slit 26a may be provided at the coil end 20e. That is, the length of the slit 26a may be longer than the coil side 20s. In other words, the length of the slit 26a may be longer than the thickness of the teeth 13 (the length between the end surfaces 13a and 13b of the teeth). Furthermore, at least one of one end and the other end of the slit 26a may be provided inside the coil side 20s. That is, the length of the slit 26a may be shorter than the coil side 20s. In other words, the length of slit 26 a may be smaller than the thickness of tooth 13 .

The plurality of slits 26a are arranged at predetermined intervals in the circumferential direction Dc. The plurality of slits 26a are arranged at equal intervals in the circumferential direction Dc. The plurality of slits 26a are arranged evenly over the entire coil side 20s in the circumferential direction Dc when viewed from the radial direction Dr. The plurality of slits 26a have the same shape when viewed from the radial direction Dr. The slit 26a has an elongated rectangular shape when viewed in the radial direction Dr.

As shown in FIG. 1 , in a cross-sectional view perpendicular to the rotating shaft 51 of the rotor 50 surrounded by the stator iron core 10 , the flat coil 20 has more windings around the inner peripheral surface 11 as it is wound closer to the inner peripheral surface 11 . It includes a reduced width portion 21 in which the width w in the direction Dc is reduced. In the width reduction portion 21, the thickness t of the inner peripheral surface 11 in the radial direction Dr increases as the width w of the inner peripheral surface 11 in the circumferential direction Dc decreases. As described above, in the width reduction portion 21, the width w of the inner peripheral surface 11 in the circumferential direction Dc and the thickness t of the inner peripheral surface 11 in the radial direction Dr vary. The product of the width w and the thickness t of the rectangular coil 20 in the radial direction Dr is constant.

When manufacturing the rectangular coil 20 which has the through-hole portion 26, the width w and the thickness t vary in each part of the rectangular coil 20, and the product of the width w and the thickness t is constant, For example, one plate member 20a having a desired width w and thickness t is formed for each winding. A through-hole portion 26 is formed in the winding closest to the inner peripheral surface 11 . These plate members 20a are joined together while being laminated in the direction of thickness t. Portions of the plate members 20a other than the portions joined to each other are insulated from each other. Thus, the rectangular coil 20 of this embodiment can be manufactured. The teeth 13 are fixed to the back yoke 14 after the rectangular coils 20 are attached to the teeth 13 .

In the present embodiment, the width reduction portion 21 is wound around all the portions of the approach side portion 16 and the separation side portion 17 of the teeth 13 where the rectangular coils 20 are wound. The reduced width portion 21 may be wound on a portion of the inner peripheral surface 11 side of the approach side portion 16 and the detachment side portion 17 of the teeth 13 where the rectangular coils 20 are wound. Further, the width reduction portion 21 may be wound only around the approach side portion 16 of the tooth 13 .

As indicated by the magnetic flux lines F and the high magnetic flux density portion P in FIG. For this reason, like the electric motor 800 provided with the conventional stator 100 shown in FIG. If the width w of Dc and the thickness t in the radial direction of Dr do not vary in any winding, the magnetic flux linkage area of the rectangular coil 200 is is large, and the eddy current loss generated in the rectangular coil 20 is large. In particular, as shown in FIG. 5, the inner surface 27 of the rectangular coil 200 is uniformly continuous at the winding closest to the inner peripheral surface 11, so that the coil side between the coil ends 200e of the rectangular coil 200 At 200 s, a current loop L of a large eddy current is generated, and the eddy current loss generated in the rectangular coil 200 is increased.

On the other hand, as shown in FIG. 2, according to the present embodiment, the stator core has a plurality of slots 12 opening on the inner peripheral surface 11 and a plurality of teeth 13 formed between the slots 12 adjacent to each other. 10 and a rectangular coil 20 wound around each tooth 13 , the rectangular coil 20 has a through hole portion 26 penetrating from an inner surface 27 to an outer surface 28 . For this reason, the current loop L of the eddy current due to the leakage magnetic flux from the inner surface 27 to the outer surface 28 of the rectangular coil 20 is divided by the through hole portion 26, and the current loop L of a large eddy current is less likely to occur. Therefore, the eddy current loss generated in the rectangular coil 20 can be reduced.

Further, according to the present embodiment, the rectangular coil 20 has the through-hole portion 26 at the winding closest to the inner peripheral surface 11 where eddy currents due to leakage magnetic flux are likely to occur. Loss can be reduced more effectively.

Further, according to the present embodiment, in a cross-sectional view perpendicular to the rotating shaft 51 of the rotor 50 surrounded by the stator core 10, the approaching side portion 16 on the side where the rotating rotor 50 approaches the teeth 13 and , when the teeth 13 are divided into two parts, the detachment side portion 17 from which the rotor 50 rotating on the teeth 13 is detached, the through hole portion 26 is provided in the approach side portion 16, so that the tip portion of the teeth 13 It is possible to more effectively reduce the eddy current loss generated in the rectangular coil 20 on the approach side portion 16 where magnetic flux saturation is likely to occur.

Further, according to the present embodiment, the rectangular coil 20 has the through hole portion 26 in the coil side 20s accommodated in the slot 12, which causes the problem of eddy current loss due to leakage magnetic flux. Since the coil ends 20e wound around the teeth 13 outside the slots 12 do not have the through holes 26, the eddy current loss generated in the rectangular coil 20 can be reduced by simply providing the through holes 26 at necessary locations. can be reduced.

Further, according to the present embodiment, since the rectangular coil 20 includes the reduced width portion 21 in which the width w of the inner peripheral surface 11 in the circumferential direction Dc decreases as the winding nearer to the inner peripheral surface 11 is wound, an eddy current due to leakage magnetic flux is generated. The eddy current loss generated in the rectangular coil 20 can be reduced by reducing the interlinkage area of the magnetic flux in windings close to the inner peripheral surface 11 where loss is likely to occur.

Further, according to the present embodiment, in the reduced-width portion 21, as the width w of the inner peripheral surface 11 in the circumferential direction Dc decreases, the thickness t of the inner peripheral surface 11 in the radial direction Dr increases. By reducing the variation in the cross-sectional area of the rectangular coil 20, the variation in the resistance value of each part of the rectangular coil 20 can be reduced. Furthermore, the stator 1 of the present embodiment can be easily manufactured by winding the rectangular coils 20 of the present embodiment around the teeth 13 of the existing stator core 10 .

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, as shown in FIGS. 6A and 6B, the length and number of slits in the through-hole portion of the modified example can be arbitrarily changed. Specifically, as shown in FIG. 6A, the rectangular coil 20A may have through holes 31. As shown in FIG. The through-hole portion 31 has a plurality of slits 31a, 31b, 31c, 31d extending in a direction parallel to the rotating shaft 51 of the rotor 50. As shown in FIG. The slits 31a, 31b, 31c, and 31d have the same shape when viewed from the radial direction Dr. The slits 31a, 31b, 31c, and 31d have an elongated rectangular shape when viewed from the radial direction Dr. The slits 31a, 31b, 31c, and 31d are arranged point-symmetrically when viewed from the radial direction Dr. The slits 31a, 31b, 31c, 31d are shorter than the slit 26a. That is, the slits 31a, 31b, 31c, and 31d do not extend over the entire coil side 20s in the direction parallel to the rotating shaft 51. As shown in FIG.

The slits 31a and 31d are positioned at both ends of the coil side 20s in the direction parallel to the rotation shaft 51 when viewed from the radial direction Dr. One end of the slit 31 a in the direction parallel to the rotating shaft 51 coincides with one end of the teeth 13 in the direction parallel to the rotating shaft 51 . The other end of the slit 31 d in the direction parallel to the rotating shaft 51 coincides with the other end of the teeth 13 in the direction parallel to the rotating shaft 51 . The slits 31a and 31d are positioned at the center of the coil side 20s in the circumferential direction Dc when viewed from the radial direction Dr.

The slits 31b and 31c are positioned at the center of the coil side 20s in the direction parallel to the rotating shaft 51 when viewed from the radial direction Dr. The slits 31b and 31c are located between the slits 31a and 31d in the direction parallel to the rotating shaft 51 . One ends of the slits 31b and 31c in the direction parallel to the rotating shaft 51 match the other ends of the slits 31a in the direction parallel to the rotating shaft 51, respectively. The other ends of the slits 31b and 31c in the direction parallel to the rotating shaft 51 match one end of the slit 31d in the direction parallel to the rotating shaft 51, respectively. The slits 31b and 31c are positioned at both ends of the coil side 20s in the circumferential direction Dc when viewed from the radial direction Dr.

As shown in FIG. 6B, the rectangular coil 20B may have through holes 32. As shown in FIG. The through-hole portion 32 has a plurality of slits 32a, 32b, 32c, 32d, 32e, 32f, and 32g extending in a direction parallel to the rotating shaft 51 of the rotor 50. As shown in FIG. The slits 32a, 32b, 32c, 32d, 32e, 32f, and 32g have the same shape when viewed from the radial direction Dr. The slits 32a, 32b, 32c, 32d, 32e, 32f, and 32g have an elongated rectangular shape when viewed from the radial direction Dr. The slits 32a, 32b, 32c, 32d, 32e, 32f, and 32g are arranged point-symmetrically when viewed from the radial direction Dr. Slits 32a, 32b, 32c, 32d, 32e, 32f, and 32g are shorter than slit 26a. That is, the slits 32a, 32b, 32c, 32d, 32e, 32f, and 32g do not extend over the entire coil side 20s in the direction parallel to the rotating shaft 51. As shown in FIG.

The slits 32a and 32b are positioned at one end of the coil side 20s in the direction parallel to the rotation axis 51 when viewed from the radial direction Dr. One ends of the slits 32 a and 32 b in the direction parallel to the rotating shaft 51 coincide with one ends of the teeth 13 in the direction parallel to the rotating shaft 51 . The slits 32a and the slits 32b are arranged side by side with a predetermined interval in the circumferential direction Dc. The slits 32a and the slits 32b are arranged evenly over the entire coil side 20s in the circumferential direction Dc when viewed from the radial direction Dr.

The slits 32f and 32g are positioned at the other end of the coil side 20s in the direction parallel to the rotation axis 51 when viewed from the radial direction Dr. The other ends of the slits 32 f and 32 g in the direction parallel to the rotating shaft 51 match the other ends of the teeth 13 in the direction parallel to the rotating shaft 51 . The slits 32f and 32g are arranged side by side with a predetermined interval in the circumferential direction Dc. The slits 32f and 32g are arranged evenly over the entire coil side 20s in the circumferential direction Dc when viewed from the radial direction Dr.

The slits 32c, 32d, and 32e are positioned at the central portion of the coil side 20s in the direction parallel to the rotating shaft 51 when viewed from the radial direction Dr. The slits 32c, 32d, and 32e are located between the slits 32a and 32b and the slits 32f and 32g in the direction parallel to the rotating shaft 51. As shown in FIG. One ends of the slits 32c, 32d, and 32e in the direction parallel to the rotating shaft 51 match the other ends of the slits 32a and 32b in the direction parallel to the rotating shaft 51, respectively. The other ends of the slits 32c, 32d, and 32e in the direction parallel to the rotating shaft 51 match the ends of the slits 32f and 32g in the direction parallel to the rotating shaft 51, respectively. The slits 32c, 32d, and 32e are arranged at predetermined intervals in the circumferential direction Dc. The slits 32c, 32d, and 32e are arranged at equal intervals in the circumferential direction Dc. The slits 32c, 32d, and 32e are arranged evenly over the entire coil side 20s in the circumferential direction Dc when viewed from the radial direction Dr.

In addition, in the above-described embodiment and modified example, the rectangular coils 20, 20A, and 20B are mainly described as having the through holes 26, 26A, and 26B in the winding closest to the inner peripheral surface 11. The coils 20 , 20 A, 20 B may have through holes 26 , 26 A, 26 B in turns other than the turns closest to the inner peripheral surface 11 . That is, the through holes 26, 26A, and 26B are formed by the plate members 20a at the ends of the flat coils 20, 20A, and 20B on the outer peripheral surface 18 side of the plurality of plate members 20a of the flat coils 20, 20A, and 20B, or the flat coils. It may be formed on the plate member 20a between the plate member 20a at the end portion of the flat coil 20 on the inner peripheral surface 11 side and the plate member 20a at the end portion on the outer peripheral surface 18 side of the rectangular coil 20 . In other words, the through holes 26, 26A, 26B may be formed in the plate member 20a of any one of the rectangular coils 20, 20A, 20B.

Further, in the above-described embodiment, the through-hole portion 26 is provided only on the approach side portion 16 , but the through-hole portion 26 may be provided on the detachment side portion 17 . In other words, the through hole portion 26 may be provided in the coil side 20s of the plate member 20a of the rectangular coil 20 on the detachable side portion 17 side. Further, the through hole portion 26 may be formed in the coil end 20e of the plate member 20a of the rectangular coil 20. As shown in FIG. As described above, it is sufficient that the rectangular coil 20 is formed with the through holes 26, 26A, and 26B penetrating through any one of the plate members 20a. Also, the through holes 26, 26A, 26B may have one slit.

Further, for example, the slots 12 of the stator core 10 are not of a semi-open slot type, and the width in the circumferential direction Dc of the tips of the teeth 13 near the inner peripheral surface 11 is the width of the ends of the teeth 13 near the back yoke 14. The present invention is applicable even if the width is not wider than the width in the circumferential direction Dc. That is, the present invention can be applied regardless of the shape of the teeth 13.

1 Stator 10 Stator core 11 Inner peripheral surface 12 Slot 13 Teeth 16 Approaching side portion 17 Retracting side portion 18 Outer peripheral surface 20, 20A, 20B Flat coil 20s Coil side 20e Coil end 21 Width reduction parts 26, 26A, 26B Through hole Part 27 Inner surface 28 Outer surface 50 Rotor 51 Axis of rotation Dc Circumferential direction Dr Radial direction t Thickness w Width

Claims (6)

a stator core having a plurality of slots opening on an inner peripheral surface and a plurality of teeth formed between the slots adjacent to each other;
a rectangular coil wound around each of the teeth;
with
The stator has a through-hole extending from an inner surface of the flat coil facing the inner peripheral surface to an outer surface of the flat coil facing the outer peripheral surface of the stator core. 2. The stator according to claim 1, wherein said rectangular coil has said through-hole portion in the winding closest to said inner peripheral surface. In a cross-sectional view perpendicular to the rotation axis of the rotor surrounding the stator iron core, the approaching side portion on the side where the rotor rotating to the teeth approaches and the rotor rotating to the teeth are separated. When the teeth are divided into two with the detached side part on the side,
3. The stator according to claim 1 or 2, wherein the through hole portion is provided on the approach side portion. Claims 1 to 3, wherein the rectangular coil has the through-hole portion in the coil side accommodated in the slot, and does not have the through-hole portion in the coil end wound around the teeth outside the slot. The stator according to any one of . The stator according to any one of claims 1 to 4, wherein the rectangular coil includes a reduced width portion in which the width of the inner peripheral surface in the circumferential direction decreases with winding closer to the inner peripheral surface. 6 . The stator according to claim 5 , wherein in the width reduction portion, the radial thickness of the inner peripheral surface increases as the width of the inner peripheral surface decreases in the circumferential direction.

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