WO2018185879A1

WO2018185879A1 - Stator core piece and rotary electric machine

Info

Publication number: WO2018185879A1
Application number: PCT/JP2017/014241
Authority: WO
Inventors: 雄一朗中村; 智也内村; 信一山口; 治之長谷川
Original assignee: 三菱電機株式会社
Priority date: 2017-04-05
Filing date: 2017-04-05
Publication date: 2018-10-11
Also published as: KR102077593B1; TW201838290A; CN110036552B; TWI672891B; KR20190064662A; CN110036552A; JPWO2018185879A1; JP6309178B1

Abstract

The present invention is characterized in that: a plurality of stator core pieces (11a) constituting an annular stator core are configured from a back yoke (11a1) and teeth (11a2) provided on the inner peripheral side of the back yoke (11a1); the teeth (11a2) are provided with a base section (11a22) extending from the peripheral center of the back yoke (11a1) in the direction toward a central axis, and a tip section (11a21) provided on the inner peripheral side of the base section (11a22); on an inner peripheral section of the tip section (11a21), a groove (3) is formed to have a shape in which the circumferential width thereof changes in stages toward the outside in a radial direction of the stator core; and when the width in the radius vector direction from a first intersection point (IP1) to a second intersection point (IP2) is a first width, and the width in the radius vector direction from the first intersection point (IP1) to a third intersection point (IP3) is a second width, the second width is narrower than the first width.

Description

Stator core piece and rotating electric machine

The present invention relates to a stator core piece composed of a back yoke and a plurality of teeth provided on the inner peripheral side of the back yoke, and a rotating electrical machine.

A stator iron core of a rotating electrical machine disclosed in Patent Document 1 includes a yoke and a plurality of teeth provided on the yoke, and is arranged at the center of the stator iron core on the radially inner side of the teeth to reduce vibration due to torque pulsation. A notch that opens toward the top is formed. The width of the notch in the radial direction of the rotating electrical machine is wider than the width of the notch in the circumferential direction of the central axis of the rotating electrical machine.

Japanese Patent No. 4114372

However, in the stator core disclosed in Patent Document 1, there is a problem that only one of the cogging torque generated due to the combination of the number of magnetic poles and the number of slots and the cogging torque generated due to variation in the magnetic force of the magnet can be reduced. was there.

The present invention has been made in view of the above, and is capable of reducing both the cogging torque generated due to the combination of the number of magnetic poles and the number of slots and the cogging torque generated due to variations in the magnetic force of the magnet. Aim to obtain child core pieces.

In order to solve the above-described problems and achieve the object, the stator core piece of the present invention is a plurality of stator core pieces constituting an annular stator core, and the stator core piece includes a back yoke and A tooth provided on the inner peripheral side of the back yoke, and the tooth includes a base portion extending in the central axis direction from the circumferential center of the back yoke, and a tip portion provided on the inner peripheral side of the base portion, A groove having a shape in which the width in the circumferential direction changes stepwise toward the outer side in the radial direction of the stator core is formed in the inner peripheral portion of the distal end portion. From the first intersection of a virtual curve obtained by extending the circumferential curve to the groove and a bisector that bisects the tip in the circumferential direction, the second of the boundary between the base and the tip and the bisector The radial width to the intersection is the first width, and from the first intersection to the bottom of the groove A third radial width to the intersection with bisector, when the second width, the second width, and wherein the narrower than the first width.

The stator core piece according to the present invention has an effect of reducing both the cogging torque generated due to the combination of the number of magnetic poles and the number of slots and the cogging torque generated due to variations in the magnetic force of the magnet.

Sectional drawing of the direction orthogonal to the axial direction of the center axis | shaft of the rotary electric machine provided with the stator core which concerns on Embodiment 1 The perspective view of the stator core piece shown in FIG. The figure which looked at the stator core piece shown in FIG. 1 from the end surface side of the stator core in the axial direction of the central axis of a rotary electric machine The figure which shows the 1st modification of the stator core piece shown in FIG. The figure which shows the 2nd modification of the stator core piece shown in FIG. The figure which shows the 3rd modification of the stator core piece shown in FIG. The figure which shows the 4th modification of the stator core piece shown in FIG. The figure which shows the 5th modification of the stator core piece shown in FIG. The figure which shows the 6th modification of the stator core piece shown in FIG. The figure which shows the 7th modification of the stator core piece shown in FIG. The figure which shows the 8th modification of the stator core piece shown in FIG. The perspective view of the stator core which concerns on Embodiment 2. FIG. 1st figure which shows the relationship between the cogging torque which arises with the rotor which concerns on

Embodiment

1, 2 and the width | variety of a groove | channel. 2nd figure which shows the relationship between the cogging torque which arises with the rotor which concerns on

Embodiment

1, 2 and the width | variety of a groove | channel.

Hereinafter, a stator core piece and a rotating electrical machine according to an embodiment of the present invention will be described in detail based on the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view in a direction orthogonal to the axial direction of the central axis of the rotating electrical machine including the stator core according to the first embodiment. FIG. 2 is a perspective view of the stator core piece shown in FIG. FIG. 3 is a view of the stator core piece shown in FIG. 1 as viewed from the end face side of the stator core in the axial direction of the central axis of the rotating electrical machine.

A rotating electrical machine 100 shown in FIG. 1 includes a stator 1 and a rotor 2 provided inside the stator 1. The rotating electrical machine 100 is a 10-pole 12-slot motor.

The rotor 2 includes a rotor core 21, a shaft 22 provided on the rotor core 21, and a plurality of permanent magnets 23. In the rotor 2, the number of magnetic poles 24 by the permanent magnet 23 is ten.

The rotor core 21 is configured by laminating a plurality of thin plates punched out from an electromagnetic steel plate base material (not shown) in the axial direction of the central axis AX of the annular stator core 11. The axial direction of the central axis AX of the stator core 11 is the direction indicated by the arrow D1 in FIG. 2 and is equal to the axial direction of the central axis of the rotating electrical machine 100. The plurality of thin plates are fixed to each other by caulking, welding, or bonding. A gap is secured between the rotor core 21 and the stator 1. The plurality of permanent magnets 23 may be embedded in the rotor core 21 or may be provided on the outer peripheral surface of the rotor core 21. The shaft 22 is fixed to the axial center portion of the rotor core 21 by shrink fitting, cold fitting or press fitting.

The stator 1 includes a stator core 11 configured by annularly connecting a plurality of stator core pieces 11a, and a winding 12 formed by winding a coil that generates a rotating magnetic field around the stator core 11. Prepare. The stator core piece 11a is configured by laminating a plurality of thin plates punched out in a T shape from an electromagnetic steel plate base material (not shown) in the axial direction D1. The plurality of thin plates are fixed to each other by caulking, welding, or bonding. In the stator core piece 11a, the cross-sectional shape perpendicular to the axial direction D1 is symmetric with respect to the bisector CP10 of the cross-sectional shape. The bisector CP10 is a line that bisects the distal end portion 11a21 in the circumferential direction D2. This is a line extending from the circumferential center 11a111 of the back yoke 11a1 in the direction of the central axis AX. The center 11a111 in the circumferential direction is located on the line 8 that bisects the width of the outer peripheral portion 11a11 of the back yoke 11a1 in the circumferential direction D2.

Each of the plurality of stator core pieces 11a includes a back yoke 11a1 and teeth 11a2 provided on the inner peripheral side 11a1a of the back yoke 11a1. The teeth 11a2 extend from the back yoke 11a1 toward the central axis AX. The teeth 11a2 include a base portion 11a22 extending from the circumferential center 11a111 of the back yoke 11a1 in the central axis AX direction, and a distal end portion 11a21 provided on the inner peripheral side of the base portion 11a22. A line indicated by reference numeral 11a22a represents a boundary between the base portion 11a22 and the distal end portion 11a21. Each of the plurality of teeth 11a2 is radially spaced apart from each other in the circumferential direction D2 of the stator 1. The circumferential direction D2 is equal to the circumferential direction of the stator core 11. In the stator 1, a slot 11a3 is formed in a region between adjacent teeth 11a2.

2 and 3 show one of the plurality of stator core pieces 11a shown in FIG. The teeth 11a2 include a base portion 11a22 and a tip portion 11a21 extending from the back yoke 11a1 toward the central axis AX. The tip portion 11a21 is formed on the center side of the stator core of the tooth 11a2 in the radial direction D3. A base portion 11a23 is formed between the base portion 11a22 and the tip portion 11a21. The base portion 11a23 is located at a boundary 11a22a between the base portion 11a22 and the distal end portion 11a21. The tip portion 11a21 has a shape extending in the circumferential direction D2. The inner peripheral portion 4 of the tip portion 11a21 faces the rotor 2 shown in FIG.

A groove 3 is formed in the inner peripheral portion 4 of the tip portion 11a21. The groove 3 is formed at the central portion in the circumferential direction D2 of the tip portion 11a21. The groove 3 is constituted by the first groove 31 and the second groove 32, and has a shape in which the width in the circumferential direction D2 is gradually reduced toward the outside in the radial direction D3.

Each of the first groove 31 and the second groove 32 has a shape that is recessed from the central axis AX shown in FIG. 1 toward the outer peripheral portion 11a11 of the back yoke 11a1. The first groove 31 extends from one end surface of the teeth 11a2 to the other end surface in the axial direction D1 of the central axis AX of the stator core 11. The second groove 32 is formed at the center of the first groove 31 in the circumferential direction D2 and is formed outside the radial direction D3 of the first groove 31. The second groove 32 extends from one end surface of the teeth 11a2 to the other end surface in the axial direction D1 of the central axis AX of the stator core 11.

A corner 5 is formed at the tip 11a21. The corner portion 5 is formed between the inner peripheral portion 4 of the distal end portion 11 a 21 and the first groove 31.

As shown in FIG. 3, the width in the circumferential direction D2 of the first groove 31 is W1, the width in the circumferential direction D2 of the base portion 11a22 of the teeth 11a2 is W2, and the width in the circumferential direction D2 of the second groove 32 is W3. , The width W1 is narrower than the width W2 and wider than the width W3.

When the width from the bottom surface 32a of the second groove 32 to the corner 5 in the radial direction D3 is W4 and the width from the root 11a23 to the first intersection IP1 in the radial direction D3 is W5, the width W4 is Narrower than W5. The width W4 is equal to the maximum depth of the groove 3. The width W5 is equal to the minimum radial thickness of the distal end portion 11a21 from the inner peripheral portion 4 of the distal end portion 11a21 to the boundary 11a22a between the distal end portion 11a21 and the base portion 11a22. That is, the maximum depth of the groove 3 is shallower than the minimum radial thickness of the distal end portion 11a21. The first intersection point IP1 is an intersection point between the bisector CP10 and the virtual curve 11a4. The virtual curve 11a4 is a line obtained by extending the curve of the inner peripheral surface of the tip end portion 11a21 to the groove 3 in a cross section perpendicular to the direction of the central axis AX.

The radial width from the first intersection point IP1 to the second intersection point IP2 between the boundary 11a22a and the bisector CP10 is defined as the first width (W5), and the first intersection point IP1 to the third intersection point. When the radial width up to IP3 is the second width (W4), the second width is narrower than the first width. The third intersection point IP3 is an intersection point between the bottom surface 32a of the groove 3 and the bisector CP10.

According to the stator core 11 according to the first embodiment, the width in the circumferential direction D2 of the groove 3 is reduced stepwise toward the outside in the radial direction D3, resulting in a combination of the number of magnetic poles and the number of slots. Both the cogging torque generated and the cogging torque generated due to variations in the magnetic force of the permanent magnet 23 can be reduced. The cogging torque generated due to the combination of the number of magnetic poles and the number of slots is reduced by adjusting the width W1 of the first groove 31, and the cogging torque generated due to the variation in the magnetic force of the permanent magnet 23 is the second This is reduced by adjusting the width W3 of the groove 32.

Specifically, in the case of a rotating machine with 10 poles and 12 slots, the cogging torque generated due to the combination of the number of magnetic poles and the number of slots is 60th order and 120th order when the rotor 2 shown in FIG. Occurs in order. The 60th order is the least common multiple of 10 and 12. In the case of a 10-pole 12-slot rotating electrical machine, cogging torque generated due to variations in the magnetic force of the permanent magnet 23 is generated in orders such as the 12th order and the 24th order when the rotor 2 shown in FIG. . The 12th and 24th orders are integer multiples of the number of slots.

According to the stator core 11 according to the first embodiment, by adjusting the width W1 of the first groove 31, the cogging torque generated in the orders such as the 60th order and the 120th order is reduced. The 12th order cogging torque is reduced by adjusting the width W3. Further, in the stator core 11 according to the first embodiment, by providing the second groove 32, the 24th-order permeance increases and the 24th-order cogging torque increases, but the width of the groove 3 in the circumferential direction D2 is increased. By changing stepwise in the radial direction D3, the change in permeance becomes gentle, so the 24th order cogging torque decreases.

Further, in the stator core 11 shown in FIG. 1, the width W4 from the bottom surface 32a of the second groove 32 to the corner portion 5 in the radial direction D3 and the width W5 from the root portion 11a23 to the first intersection point IP1 in the radial direction D3. By making it narrower than this, it is possible to prevent a decrease in torque due to a decrease in gap magnetic flux density. Further, in the stator core 11 shown in FIG. 1, since the second groove 32 is formed on the bottom surface of the first groove 31, the first groove 31 and the second groove are formed in the inner peripheral portion 4 of the tip end portion 11a21. Compared with the case where 32 is formed individually, punching with a mold becomes easier. Further, since the stator core 11 shown in FIG. 1 is formed with the groove 3 having a shape satisfying the relationship of W1> W3, a decrease in gap magnetic flux density is suppressed, and a decrease in torque is suppressed.

Further, the groove 3 of the stator core piece 11a may be formed in a shape that satisfies the relationship of W1> W3 × 2. By comprising in this way, compared with the case where the groove | channel 3 of the shape where the relationship of W1> W3 is formed is formed, the fall of a gap magnetic flux density is further suppressed and the fall of a torque is further suppressed.

FIG. 4 is a view showing a first modification of the stator core piece shown in FIG. A groove 3A is formed in the teeth 11a2 of the stator core piece 11A shown in FIG. 4 instead of the groove 3 shown in FIG. The groove 3A is formed in the center portion in the circumferential direction D2 of the tip end portion 11a21 in the inner peripheral portion 4 of the tip end portion 11a21. The groove 3 A includes a first groove 31, a second groove 32, and a third groove 33. The groove 3A has a shape in which the width in the circumferential direction D2 becomes gradually smaller toward the outside of the radial direction D3, and the width in the circumferential direction D2 changes in three stages.

The third groove 33 is formed at the center of the second groove 32 in the circumferential direction D2. The third groove 33 extends from one end surface of the tooth 11a2 to the other end surface in the axial direction D1 of the central axis AX of the stator core 11 shown in FIG.

When the width in the circumferential direction D2 of the second groove 32 is W3 and the width in the circumferential direction D2 of the third groove 33 is W6, the width W6 is narrower than the width W3. When the width from the bottom surface 33a of the third groove 33 to the corner 5 in the radial direction D3 is W4, and the width from the root 11a23 to the first intersection IP1 in the radial direction D3 is W5, the width W4 is Narrower than width W5. The width W4 is equal to the maximum depth of the groove 3A. The width W5 is equal to the minimum radial thickness of the distal end portion 11a21 from the inner peripheral portion 4 of the distal end portion 11a21 to the boundary 11a22a between the distal end portion 11a21 and the base portion 11a22. That is, the maximum depth of the groove 3A is shallower than the minimum radial thickness of the tip portion 11a21.

The radial width from the first intersection point IP1 to the second intersection point IP2 between the boundary 11a22a and the bisector CP10 is defined as the first width (W5), and the first intersection point IP1 to the third intersection point. When the radial width up to IP3 is the second width (W4), the second width is narrower than the first width. The third intersection point IP3 is an intersection point between the bottom surface 33a of the groove 3A and the bisector CP10.

According to the stator core 11 using the stator core piece 11A shown in FIG. 4, due to variations in the magnetic force of the permanent magnet 23, the orders are generated at orders of integer multiples of the number of slots such as 12th order, 24th order and 60th order. And the cogging torque generated at orders other than an integral multiple of the number of slots is reduced.

FIG. 5 is a view showing a second modification of the stator core piece shown in FIG. In the teeth 11a2 of the stator core piece 11B shown in FIG. 5, a groove 3B is formed instead of the groove 3 shown in FIG. The groove 3B is formed in the center portion in the circumferential direction D2 of the tip end portion 11a21 in the inner peripheral portion 4 of the tip end portion 11a21. The groove 3B has a shape in which the width in the circumferential direction D2 gradually increases toward the outside in the radial direction D3. In other words, the groove 3B has a shape in which the width in the circumferential direction D2 becomes narrower in steps toward the inside of the radial direction D3.

The width of the groove 3B in the circumferential direction D2 on the back yoke 11a1 side is W1, the width of the base 11a22 of the teeth 11a2 in the circumferential direction D2 is W2, and the width of the groove 3B in the circumferential direction D2 opposite to the back yoke 11a1 is W3. , The width W1 is narrower than the width W2 and wider than the width W3.

A corner 5 is formed at the tip 11a21. The corner portion 5 is formed between the inner peripheral portion 4 of the tip portion 11a21 and the groove 3B. When the width from the bottom surface 3B1 of the groove 3B to the corner portion 5 in the radial direction D3 is W4 and the width from the root portion 11a23 to the first intersection point IP1 in the radial direction D3 is W5, the width W4 is larger than the width W5. narrow. The width W4 is equal to the maximum depth of the groove 3B. The width W5 is equal to the minimum radial thickness of the distal end portion 11a21 from the inner peripheral portion 4 of the distal end portion 11a21 to the boundary 11a22a between the distal end portion 11a21 and the base portion 11a22. That is, the maximum depth of the groove 3B is shallower than the minimum radial thickness of the tip portion 11a21.

The radial width from the first intersection point IP1 to the second intersection point IP2 between the boundary 11a22a and the bisector CP10 is defined as the first width (W5), and the first intersection point IP1 to the third intersection point. When the radial width up to IP3 is the second width (W4), the second width is narrower than the first width. The third intersection point IP3 is an intersection point between the bottom surface 3B1 of the groove 3B and the bisector CP10.

According to the stator core 11 using the stator core piece 11B shown in FIG. 5, due to variations in the magnetic force of the permanent magnet 23, the orders are generated at orders of integral multiples of the number of slots such as 12th order, 24th order and 60th order. And the cogging torque generated at orders other than an integral multiple of the number of slots is reduced. Further, according to the stator core 11 using the stator core piece 11B, since the width W1 is wider than the width W3, the leakage magnetic flux between the slots is reduced, and a decrease in torque at high load is suppressed. If demonstrating it concretely, in the rotary electric machine 100 at the time of high load, the leakage magnetic flux which flows into the adjacent teeth 11a2 through the front-end | tip part 11a21 will become large. Therefore, in the rotary electric machine 100 having a large slot opening width, the torque is greatly reduced. When the width W1 is wider than the width W3, the leakage magnetic flux that flows to the adjacent teeth 11a2 through the distal end portion 11a21 is suppressed at the upper portion of the slot, so that the leakage magnetic flux is reduced and the reduction in torque is reduced. The upper slot portion is a portion corresponding to a region closer to the root portion 11a23 than the tip portion 11a21 in the slot 11a3 shown in FIG.

FIG. 6 is a view showing a third modification of the stator core piece shown in FIG. A groove group 3C is formed in the tooth 11a2 of the stator core piece 11C shown in FIG. 6 instead of the groove 3 shown in FIG. The groove group 3C is formed at the central portion in the circumferential direction D2 of the tip end portion 11a21 in the inner peripheral portion 4 of the tip end portion 11a21. The groove group 3 C includes two first grooves 31 formed on the inner peripheral portion 4 of the tip end portion 11 a 21 and a second groove 32 formed on the inner peripheral portion 4 of the tip end portion 11 a 21.

The second groove 32 is provided between the two first grooves 31, and the two first grooves 31 and the second groove 32 are the first groove 31 and the second groove in the circumferential direction D2. 32 and the first groove 31 are arranged in this order. The first groove 31 and the second groove 32 are arranged apart from each other in the circumferential direction D2. A protrusion 41 is formed between the first groove 31 and the second groove 32.

A corner 51 is formed between the inner periphery 4 of the tip 11a21 and the first groove 31. A corner portion 52 is formed between the inner peripheral portion 4 of the distal end portion 11 a 21 and the second groove 32.

The width from the bottom surface 31a of the first groove 31 to the corner portion 51 in the radial direction D3 is W41, the width from the bottom surface 32a of the second groove 32 to the corner portion 52 in the radial direction D3 is W42, and the width in the radial direction D3. When the width from the base portion 11a23 to the first intersection point IP1 is W5, the width W42 is narrower than the width W5 and wider than the width W41. The width W42 is equal to the maximum depth of the second groove 32. The width W5 is equal to the minimum radial thickness of the distal end portion 11a21 from the inner peripheral portion 4 of the distal end portion 11a21 to the boundary 11a22a between the distal end portion 11a21 and the base portion 11a22. That is, the maximum depth of the second groove 32 is shallower than the minimum radial thickness of the tip end portion 11a21.

The radial width from the first intersection point IP1 to the second intersection point IP2 between the boundary 11a22a and the bisector CP10 is defined as the first width (W5), and the first intersection point IP1 to the third intersection point. When the radial width up to IP3 is the second width (W4), the second width is narrower than the first width. The third intersection point IP3 is an intersection point between the bottom surface 32a of the second groove 32 and the bisector CP10.

The width from one corner 51 in the circumferential direction D2 to the other corner 51 is W1, the width in the circumferential direction D2 of the first groove 31 is W11, and the width in the circumferential direction D2 of the base 11a22 of the tooth 11a2 is W2. When the width in the circumferential direction D2 of the second groove 32 is W3, the width W1 is narrower than the width W2, and the width W11 is narrower than the width W2 and wider than the width W3.

The groove group 3 C has a shape in which the width in the circumferential direction D 2 gradually decreases toward the outer side in the radial direction D 3, similarly to the groove 3 illustrated in FIG. 3. According to the stator core 11 using the stator core piece 11C shown in FIG. 6, the cogging torque generated due to the combination of the number of magnetic poles and the number of slots is reduced by adjusting the width W11 of the first groove 31. By adjusting the width W3 of the second groove 32, the cogging torque generated due to the variation in the magnetic force of the permanent magnet 23 is reduced. Moreover, when the shape of the first groove 31 and the second groove 32 is not a simple shape such as a circle and a rectangle, but a complicated shape such as a star shape and a V shape, the shape of a die for punching the magnetic steel sheet base material is In some cases, it becomes complicated and it becomes difficult to manufacture a metal mold and it is difficult to punch the base material of the electromagnetic steel sheet. According to the stator core 11 using the stator core piece 11C shown in FIG. 6, since the shape of the first groove 31 and the second groove 32 constituting the groove group 3C can be made a simple rectangle, Manufacture is easy and manufacture of the stator core 11 is easy.

3 to 6, the example in which the groove portion having a shape in which the width in the circumferential direction D2 becomes narrower in steps toward the outer side or the inner side in the radial direction D3 has been described. Below, the example in which the through-hole of the shape where the width | variety in the circumferential direction D2 becomes narrow in steps toward the outer side of the radial direction D3 is demonstrated.

FIG. 7 is a view showing a fourth modification of the stator core piece shown in FIG. A through hole 6 is formed in the tooth 11a2 of the stator core piece 11D shown in FIG. 7 instead of the groove 3 shown in FIG. The through hole 6 is formed at the center of the distal end portion 11a21 in the circumferential direction D2. The through hole 6 penetrates the one end surface and the other end surface of the tooth 11a2 in the axial direction D1 shown in FIG.

The through hole 6 includes a first region 6a having a width W1 in the circumferential direction D2 that is narrower than the width W2 of the base portion 11a22, and a second region 6b having a width W3 in the circumferential direction D2 that is narrower than the width W1. The second region 6b communicates with the first region 6a and is formed at the center of the first region 6a in the circumferential direction D2. The second region 6b is formed closer to the base 11a22 than the first region 6a.

The width from the end surface 6d of the second region 6b in the radial direction D3 to the end surface 6c of the first region 6a in the radial direction D3 on the side opposite to the teeth 11a2 is W4, and from the root 11a23 in the radial direction D3 to the first. When the width to the intersection IP1 is W5, the width W4 is narrower than the width W5. The width W4 is equal to the maximum depth of the through hole 6 that extends radially outward from the inner peripheral portion 4 of the distal end portion 11a21. The width W5 is equal to the minimum radial thickness of the distal end portion 11a21 from the inner peripheral portion 4 of the distal end portion 11a21 to the boundary 11a22a between the distal end portion 11a21 and the base portion 11a22. That is, the maximum depth of the through hole 6 is shallower than the minimum radial thickness of the tip end portion 11a21. The first intersection point IP1 is an intersection point between the bisector CP10 and the inner peripheral surface of the tip end portion 11a21.

The radial width from the first intersection point IP1 to the second intersection point IP2 between the boundary 11a22a and the bisector CP10 is defined as the first width (W5), and the first intersection point IP1 to the third intersection point. When the radial width up to IP3 is the second width (W4), the second width is narrower than the first width. The third intersection point IP3 is an intersection point between the radially outer end face of the through hole 6 and the bisector CP10.

Thus, the through-hole 6 has a shape in which the width in the circumferential direction D2 is gradually reduced toward the outside in the radial direction D3. According to the stator core 11 using the stator core piece 11D shown in FIG. 7, the cogging torque caused by the combination of the number of magnetic poles and the number of slots is reduced by adjusting the width W1 of the first region 6a. The cogging torque generated due to the variation in the magnetic force of the permanent magnet 23 is reduced by adjusting the width W3 of the second region 6b. Further, according to the stator core 11 using the stator core piece 11D shown in FIG. 7, since only one through hole 6 has to be formed without providing a plurality of through holes in one tooth 11a2, it depends on the mold. Punching becomes easy. Further, in the stator core 11 using the stator core piece 11D shown in FIG. 7, the

grooves

3, 3A, 3B and the groove group 3C shown in FIGS. 3 to 6 are not provided, so the

grooves

3, 3A, 3B are not provided. Compared with the case where the groove group 3C is provided, the roundness of the stator inner diameter caused by the manufacturing variation of the through-hole 6 does not decrease, and the roundness of the stator core 11 is improved. Play.

FIG. 8 is a view showing a fifth modification of the stator core piece shown in FIG. A through hole group 6A is formed in the tooth 11a2 of the stator core piece 11E shown in FIG. 8 instead of the groove 3 shown in FIG. 6 A of through-hole groups are formed in the center part in the circumferential direction D2 of the front-end | tip part 11a21. The through-hole group 6 A includes two first through-holes 61 and a second through-hole 62. The second through hole 62 is provided between the two first through holes 61, and the two first through holes 61 and the second through holes 62 are the first through holes 61 in the circumferential direction D 2. The second through hole 62 and the first through hole 61 are arranged in this order. The first through hole 61 and the second through hole 62 are arranged to be separated from each other in the circumferential direction D2.

In FIG. 8, the position of the end surface of the first through hole 61 opposite to the back yoke 11a1 in the radial direction D3 is the portion closest to the second through hole 62, and the second through hole 62 in the radial direction D3. This is the same as the position of the end surface opposite to the back yoke 11a1.

The width from the end face on the back yoke 11a1 side of the first through hole 61 in the radial direction D3 to the end face on the opposite side of the back yoke 11a1 of the first through hole 61 in the radial direction D3 is W41, and in the radial direction D3 The width from the end face on the back yoke 11a1 side of the second through hole 62 to the end face on the opposite side of the back yoke 11a1 of the second through hole 62 in the radial direction D3 is W42, and from the root part 11a23 in the radial direction D3. When the width to the first intersection point IP1 is W5, the width W42 is narrower than the width W5 and wider than the width W41. The width W42 is equal to the maximum depth of the second through hole 62 that extends radially outward from the inner peripheral portion 4 of the distal end portion 11a21. The width W5 is equal to the minimum radial thickness of the distal end portion 11a21 from the inner peripheral portion 4 of the distal end portion 11a21 to the boundary 11a22a between the distal end portion 11a21 and the base portion 11a22. That is, the maximum depth of the second through hole 62 is shallower than the minimum radial thickness of the tip end portion 11a21. The first intersection point IP1 is an intersection point between the bisector CP10 and the inner peripheral surface of the tip end portion 11a21.

The radial width from the first intersection point IP1 to the second intersection point IP2 between the boundary 11a22a and the bisector CP10 is defined as the first width (W5), and the first intersection point IP1 to the third intersection point. When the radial width up to IP3 is the second width (W4), the second width is narrower than the first width. The third intersection point IP3 is an intersection point between the radially outer end face of the second through hole 62 and the bisector CP10.

The width from one end surface of one first through hole 61 in the circumferential direction D2 to the other end surface of the other first through hole 61 in the circumferential direction D2 is W1, and the first through hole 61 in the circumferential direction D2 is defined as W1. When the width is W11, the width in the circumferential direction D2 of the base portion 11a22 of the tooth 11a2 is W2, and the width in the circumferential direction D2 of the second through hole 62 is W3, the width W1 is narrower than the width W2 and the width W11. Is narrower than the width W2 and wider than the width W3.

Thus, the through-hole group 6A has a shape in which the width in the circumferential direction D2 is gradually reduced toward the outside in the radial direction D3. According to the stator core 11 using the stator core piece 11E shown in FIG. 8, the cogging torque generated due to the combination of the number of magnetic poles and the number of slots is adjusted by adjusting the width W11 of the first through hole 61. The cogging torque that is reduced and caused by the variation in the magnetic force of the permanent magnet 23 is reduced by adjusting the width W 3 of the second through hole 62.

Further, according to the stator core 11 using the stator core piece 11E, similarly to the first groove 31 and second groove 32 shown in FIG. Since the shape of the second through hole 62 can be a simple rectangle, the mold can be easily manufactured, and the stator core 11 can be easily manufactured. Further, in the stator core 11 using the stator core piece 11E shown in FIG. 8, since the

grooves

3, 3A, 3B and the groove group 3C shown in FIGS. 3 to 6 are not provided, the

grooves

3, 3A, 3B are not provided. Compared with the case where the groove group 3C is provided, the roundness of the stator inner diameter due to the manufacturing variation of the through-hole group 6A does not decrease, and the roundness of the stator core 11 is improved. There is an effect.

FIG. 9 is a view showing a sixth modification of the stator core piece shown in FIG. A through hole group 6B is formed in the tooth 11a2 of the stator core piece 11F shown in FIG. 9 instead of the groove 3 shown in FIG. The through-hole group 6B is formed at the center portion in the circumferential direction D2 of the tip portion 11a21. The through-hole group 6B includes a first through-hole 61 and a second through-hole 62 that are arranged in the radial direction D3. The first through hole 61 and the second through hole 62 are arranged to be separated from each other in the radial direction D3. The first through hole 61 is provided closer to the inner peripheral portion 4 of the tip end portion 11a21, and the second through hole 62 is provided on the back yoke 11a1 side of the first through hole 61 and the first through hole. 61 is provided at the center in the circumferential direction D2.

The width from the end face on the back yoke 11a1 side of the second through hole 62 in the radial direction D3 to the end face on the opposite side of the back yoke 11a1 of the first through hole 61 in the radial direction D3 is W4, and in the radial direction D3. When the width from the base portion 11a23 to the first intersection point IP1 is W5, the width W4 is narrower than the width W5. The width W4 is equal to the maximum width from the inside in the radial direction of the first through hole 61 to the outside in the radial direction of the second through hole 62. The width W5 is equal to the minimum radial thickness of the distal end portion 11a21 from the inner peripheral portion 4 of the distal end portion 11a21 to the boundary 11a22a between the distal end portion 11a21 and the base portion 11a22. That is, the maximum width from the inside in the radial direction of the first through hole 61 to the outside in the radial direction of the second through hole 62 is narrower than the minimum thickness in the radial direction of the tip end portion 11a21. The first intersection point IP1 is an intersection point between the bisector CP10 and the inner peripheral surface of the tip end portion 11a21.

When the width in the circumferential direction D2 of the first through hole 61 is W1, the width in the circumferential direction D2 of the base portion 11a22 of the teeth 11a2 is W2, and the width in the circumferential direction D2 of the second through hole 62 is W3, the width W1 is narrower than the width W2 and wider than the width W3.

Thus, the through-hole group 6B has a shape in which the width in the circumferential direction D2 is gradually reduced toward the outside in the radial direction D3. According to the stator core 11 using the stator core piece 11F shown in FIG. 9, the cogging torque generated due to the combination of the number of magnetic poles and the number of slots is adjusted by adjusting the width W1 of the first through hole 61. The cogging torque that is reduced and caused by the variation in the magnetic force of the permanent magnet 23 is reduced by adjusting the width W 3 of the second through hole 62. Further, according to the stator core 11 using the stator core piece 11F, similarly to the first groove 31 and the second groove 32 shown in FIG. 6, the first through-hole 61 and the through-hole group 6B, Since the shape of the second through hole 62 can be a simple rectangle, the mold can be easily manufactured, and the stator core 11 can be easily manufactured. Further, the stator core piece 11E shown in FIG. 8 has three through holes provided in the teeth 11a2, whereas the stator core piece 11F shown in FIG. 9 has two through holes provided in the teeth 11a2. Therefore, the number of through holes can be reduced. Therefore, the stator core 11 using the stator core piece 11F shown in FIG.

FIG. 10 is a view showing a seventh modification of the stator core piece shown in FIG. A tooth 3a and a through hole 6C are formed in the teeth 11a2 of the stator core piece 11G shown in FIG. 10 instead of the groove 3 shown in FIG. The groove 3D is formed in the center portion in the circumferential direction D2 of the tip end portion 11a21 in the inner peripheral portion 4 of the tip end portion 11a21. 6 C of through-holes are formed in the center part in the circumferential direction D2 of the front-end | tip part 11a21. The through hole 6C is formed on the back yoke 11a1 side of the groove 3D in the radial direction D3.

A corner 5 is formed at the tip 11a21. The corner portion 5 is formed between the inner peripheral portion 4 of the tip end portion 11a21 and the groove 3D.

When the width from the end face on the back yoke 11a1 side of the through hole 6C in the radial direction D3 to the corner 5 is W4, and the width from the base 11a23 to the first intersection IP1 in the radial direction D3 is W5, the width W4 is , Narrower than width W5. The width W4 is equal to the maximum width from the corner portion 5 between the inner peripheral surface of the tip end portion 11a21 and the groove 3D to the outside in the radial direction of the through hole 6C. The width W5 is equal to the minimum radial thickness of the distal end portion 11a21 from the inner peripheral portion 4 of the distal end portion 11a21 to the boundary 11a22a between the distal end portion 11a21 and the base portion 11a22. The first intersection point IP1 is an intersection point between the bisector CP10 and the virtual curve 11a4.

The radial width from the first intersection point IP1 to the second intersection point IP2 between the boundary 11a22a and the bisector CP10 is defined as the first width (W5), and the first intersection point IP1 to the third intersection point. When the radial width up to IP3 is the second width (W4), the second width is narrower than the first width. The third intersection point IP3 is an intersection point between the radially outer end face of the through hole 6C and the bisector CP10.

When the width in the circumferential direction D2 of the groove 3D is W1, the width in the circumferential direction D2 of the base portion 11a22 of the teeth 11a2 is W2, and the width in the circumferential direction D2 of the through hole 6C is W3, the width W1 is larger than the width W2. Narrow and wider than width W3.

According to the stator core 11 using the stator core piece 11G shown in FIG. 10, the cogging torque generated due to the combination of the number of magnetic poles and the number of slots is reduced by adjusting the width W1 of the groove 3D. By adjusting the width W 3 of the hole 6 C, the cogging torque generated due to the variation in the magnetic force of the permanent magnet 23 is reduced. In addition, according to the stator core 11 using the stator core piece 11G, the shape of the through-hole 6C and the groove 3D can be made a simple rectangle, like the first groove 31 and the second groove 32 shown in FIG. Therefore, the mold can be easily manufactured, and the stator core 11 can be easily manufactured. In addition, according to the stator core 11 using the stator core piece 11G, the gap WD density is reduced by making the width W1 of the groove 3D larger than the width W3 of the through hole 6C, thereby minimizing torque reduction. To the limit.

In FIG. 10, the example in which the width W1 of the groove 3D is wider than the width W3 of the through hole 6C has been described. However, the same effect can be obtained even when the width W1 of the groove 3D is narrower than the width W3 of the through hole 6C. Is obtained.

FIG. 11 is a view showing an eighth modification of the stator core piece shown in FIG. In the teeth 11a2 of the stator core piece 11H shown in FIG. 11, two grooves 3E and through holes 6D are formed instead of the grooves 3 shown in FIG. The two grooves 3E and the through-hole 6D are formed in the center portion in the circumferential direction D2 of the tip end portion 11a21 in the inner peripheral portion 4 of the tip end portion 11a21. The through hole 6D is provided between the two grooves 3E, and the two grooves 3E and the through hole 6D are arranged in the order of the groove 3E, the through hole 6D, and the groove 3E in the circumferential direction D2.

A corner portion 5 is formed between the inner peripheral portion 4 of the tip portion 11a21 and the groove 3E. The width from the end face on the back yoke 11a1 side of the through hole 6D in the radial direction D3 to the corner portion 5 is W41, the width from the bottom surface 3E1 to the corner portion 5 of the groove 3E in the radial direction D3 is W42, and the root in the radial direction D3. When the width from the portion 11a23 to the first intersection IP1 is W5, the width W41 is narrower than the width W5 and wider than the width W42. The width W42 is narrower than the width of the through hole 6D in the radial direction D3. The width W4 is equal to the maximum width from the corner portion 5 between the inner peripheral surface of the tip end portion 11a21 and the groove 3E to the radially outer side of the through hole 6D. The width W5 is equal to the minimum radial thickness of the distal end portion 11a21 from the inner peripheral portion 4 of the distal end portion 11a21 to the boundary 11a22a between the distal end portion 11a21 and the base portion 11a22. The first intersection point IP1 is an intersection point between the bisector CP10 and the inner peripheral surface of the tip end portion 11a21.

The radial width from the first intersection point IP1 to the second intersection point IP2 between the boundary 11a22a and the bisector CP10 is defined as the first width (W5), and the first intersection point IP1 to the third intersection point. When the radial width up to IP3 is the second width (W4), the second width is narrower than the first width. The third intersection point IP3 is an intersection point between the radially outer end face of the through hole 6D and the bisector CP10.

The width from one end surface of one groove 3E in the circumferential direction D2 to the other end surface of the other groove 3E in the circumferential direction D2 is W1, the width in the circumferential direction D2 of the groove 3E is W11, and the circumference of the base portion 11a22 of the teeth 11a2 When the width in the direction D2 is W2 and the width of the through hole 6D in the circumferential direction D2 is W3, the width W1 is narrower than the width W2, and the width W3 is narrower than the width W1 and equal to the width W11.

According to the stator core 11 using the stator core piece 11H shown in FIG. 11, the cogging torque caused by the combination of the number of magnetic poles and the number of slots is reduced by adjusting the width W1 including the two grooves 3E. By adjusting the width W3 of the through hole 6D, the cogging torque generated due to the variation in the magnetic force of the permanent magnet 23 is reduced. Further, according to the stator core 11 using the stator core piece 11H, the shapes of the through holes 6D and the grooves 3E can be made into a simple rectangle, similarly to the first groove 31 and the second groove 32 shown in FIG. Therefore, the mold can be easily manufactured, and the stator core 11 can be easily manufactured. Moreover, according to the stator core 11 using the stator core piece 11H, the cogging torque generated due to the combination of the number of magnetic poles and the number of slots is further reduced by providing the plurality of grooves 3E.

Embodiment 2. FIG.
FIG. 12 is a perspective view of a stator core according to the second embodiment. The stator core 1A includes a plurality of stator core pieces 11J instead of the plurality of stator core pieces 11a shown in FIG. Grooves 3 shown in FIG. 3 are formed at a plurality of locations in the tip 11a21 of the teeth 11a2 of the stator core piece 11J. Each of the plurality of grooves 3 is arranged to be separated from each other in the axial direction D1. The stator core piece 11J includes a first steel plate group 7a constituted by a plurality of thin plates in which the grooves 3 are formed, and a second steel plate group 7b constituted by a plurality of thin plates in which the grooves are not formed. The layers are alternately stacked in the axial direction D1.

In the stator core 1A, the first groove 31 and the second groove shown in FIG. 3 are reversed so that the phases of the cogging torque generated in the first steel plate group 7a and the cogging torque generated in the second steel plate group 7b are reversed. The width of each groove 32 in the circumferential direction D2 is adjusted. The phase and amplitude of the cogging torque generated due to the combination of the number of magnetic poles and the number of slots is adjusted by the width W1 of the first groove 31, and the phase and amplitude of the cogging torque generated due to the variation in the magnetic force of the permanent magnet 23. Is adjusted by the width W3 of the second groove 32.

By adjusting the stack thickness in the axial direction D1 of the first steel plate group 7a and the second steel plate group 7b, the amplitude of the cogging torque whose phase is reversed in each tooth is adjusted, and the cogging torque generated in each tooth is adjusted. Addition reduces the cogging torque of the entire stator. Further, the groove 3 is partially formed in the distal end portion 11a21, so that the gap magnetic flux density is higher than that in the case where the groove 3 is formed from one end to the other end in the axial direction D1 of the distal end portion 11a21. The effect is that the decrease is suppressed and the torque is improved.

In the second embodiment, three grooves 3 are formed from one end to the other end of the tip end portion 11a21 in the axial direction D1, but the number of grooves 3 is limited to the illustrated example as long as the number is three or more. is not.

In the second embodiment, the example in which the groove 3 is formed has been described. However, instead of the groove 3, the groove shown in FIGS. 4 to 6 or the through hole shown in FIGS. The same effect can be obtained even when two or more tip portions 11a21 in the direction D1 are formed from one end to the other end.

In the second embodiment, the example in which the groove 3 is formed has been described. However, instead of the groove 3, the set of the groove and the through-hole shown in FIG. 10 or 11 is replaced with one end of the tip end portion 11a21 in the axial direction D1. Even when two or more are formed from the first to the other end, the same effect can be obtained.

In the first and second embodiments, the example in which the grooves or the through holes are formed in the teeth provided in the stator core of the rotating electrical machine has been described. However, the grooves or the through holes described in the first and second embodiments are linear. The same effect can be obtained when applied to a stator of a motor.

In the first and second embodiments, the groove or the through hole is formed at the center portion in the circumferential direction D2 of the tooth tip portion, but the groove or the through hole is located at a position near the end portion in the circumferential direction D2 of the tooth tip portion. Even if it is formed, the same effect can be obtained as long as the width of the groove or the through hole in the circumferential direction D2 is gradually narrowed toward the outside or the inside of the radial direction D3.

Further, in the first and second embodiments, the groove or the through hole is formed symmetrically in the circumferential direction D2 with respect to the center portion in the circumferential direction D2 of the tooth tip, but the width of the groove or the through hole in the circumferential direction D2 is The same effect can be obtained even if the shape is asymmetrical as long as the shape becomes narrower stepwise toward the outside or inside of the radial direction D3.

In the first and second embodiments, the stator core configured by connecting a plurality of stator core pieces in a ring shape has been described. Instead of the stator core configured by a plurality of stator core pieces, A stator core formed by stacking the stator core pieces punched out into a joint, a joint wrap core in which a part of the stator core is connected, a joint wrap core in which the stator core partially overlaps, In any of the core inner and outer divided cores from which the core back and the teeth are separated, the groove or the through-hole having a shape in which the width in the circumferential direction D2 of the groove or the through-hole is gradually reduced toward the outside or the inside in the radial direction D3. By forming, the same effect can be obtained.

FIG. 13 is a first diagram showing the relationship between the cogging torque generated in the rotor according to the first and second embodiments and the groove width. The vertical axis in FIG. 13 represents the cogging torque T1 caused by the variation in the magnetic force of the magnet, and the horizontal axis in FIG. 13 represents the ratio of the width W3 of the second groove 32 shown in FIG. It is represented by. FIG. 14 is a second diagram showing the relationship between the cogging torque generated in the rotor according to the first and second embodiments and the groove width. The vertical axis in FIG. 14 represents the cogging torque T2 generated due to the combination of the number of magnetic poles and the number of slots, and the horizontal axis in FIG. 14 represents the width W1 of the first groove 31 shown in FIG. Is expressed as a ratio.

By changing the width W3 of the second groove 32, the permeance distribution of the gap changes, and the amplitude and phase of cogging torque caused by the permeance change. The inclination of the cogging torque in the region where the width W3 of the second groove 32 is smaller than 0.4 [pu], and the cogging torque in the region where the width W3 of the second groove 32 is larger than 0.4 [pu]. It can be seen that the inclination is different. Further, the inclination of the cogging torque in the region where the width W1 of the first groove 31 is smaller than 0.4 [pu], and the region in which the width W1 of the first groove 31 is larger than 0.7 [pu]. It can be seen that the slope of the cogging torque is different. It can also be seen that the slope of the cogging torque changes when the width W1 of the first groove 31 is 0.4 [p.u] to 0.7 [p.u]. In the stator core according to the present embodiment, the relationship between the cogging torque and the groove width is considered, and the width of the groove or the through hole is set.

The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

1 stator, 2 rotor, 3, 3A, 3B, 3D, 3E groove, 3B1, 3E1, 31a, 32a, 33a bottom surface, 3C groove group, 4, inner periphery, 5, 51, 52 corner, 6, 6C , 6D through-hole, 6A, 6B through-hole group, 6a first region, 6b second region, 6c, 6d end face, 7a first steel plate group, 7b second steel plate group, 8-wire, 11

stator core

11a, 11A, 11B, 11C, 11D, 11E, 11F, 11G, 11H, 11J Stator core piece, 11a1 back yoke, 11a1a inner peripheral side, 11a22a boundary, 11a11 outer peripheral part, 11a111 peripheral direction center, 11a2 teeth, 11a21 Tip, 11a22 base, 11a23 root, 11a3 slot, 11a4 virtual curve, 12 windings, 21 rotor core , 22 shaft, 23 permanent magnet, 24 magnetic pole, 31 first groove, 32 second groove, 33 third groove, 41 protrusion, 61 first through hole, 62 second through hole, 100 rotating electrical machine, IP1 first intersection, IP2 second intersection, IP3 third intersection.

Claims

A plurality of stator core pieces constituting an annular stator core,
The stator core piece is composed of a back yoke and teeth provided on the inner peripheral side of the back yoke,
The teeth include a base portion extending in the central axis direction from the circumferential center of the back yoke, and a tip portion provided on the inner peripheral side of the base portion,
A groove having a shape in which the width in the circumferential direction changes stepwise toward the outer side in the radial direction of the stator core is formed in the inner peripheral portion of the tip portion,
From a first intersection of a virtual curve obtained by extending the curve of the inner peripheral surface of the tip to the groove and a bisector that bisects the tip in the circumferential direction in a cross section perpendicular to the central axis direction. The radial width to the second intersection of the boundary between the base and the tip and the bisector is the first width,
When the radial width from the first intersection point to the third intersection point of the bottom surface of the groove and the bisector is the second width,
The stator core piece, wherein the second width is narrower than the first width.
The groove having a shape in which the width in the circumferential direction gradually decreases toward the outer side in the radial direction is formed in a first groove and a central portion of the first groove in the circumferential direction and the first groove. A second groove formed outside the radial direction of the first groove,
2. The stator core piece according to claim 1, wherein a width of the first groove in the circumferential direction is wider than a width of the second groove in the circumferential direction.
The stator core piece according to claim 2, wherein a width of the first groove in the circumferential direction is wider than twice a width of the second groove in the circumferential direction.
A plurality of stator core pieces constituting an annular stator core,
The stator core piece is composed of a back yoke and teeth provided on the inner peripheral side of the back yoke,
The teeth include a base portion extending in the central axis direction from the circumferential center of the back yoke, and a tip portion provided on the inner peripheral side of the base portion,
A plurality of first grooves arranged in a circumferential direction apart from each other and a second groove provided between each of the plurality of first grooves are formed in the inner peripheral portion of the tip portion,
The width of the second groove in the radial direction of the stator core is wider than the width of the first groove in the radial direction,
A virtual curve obtained by extending a curve of the inner peripheral surface of the tip portion to the second groove in a cross section perpendicular to the central axis direction and a bisector that bisects the tip portion in the circumferential direction. The radial width from the intersection of the base to the second intersection of the boundary between the base and the tip and the bisector is defined as the first width,
The radial width from the first intersection point to the third intersection point of the bottom surface of the second groove and the bisector from the inner peripheral portion of the tip portion toward the outer side in the radial direction, With the second width,
The stator core piece, wherein the second width is narrower than the first width.
A plurality of stator core pieces constituting an annular stator core,
The stator core piece is composed of a back yoke and teeth provided on the inner peripheral side of the back yoke,
The teeth include a base portion extending in the central axis direction from the circumferential center of the back yoke, and a tip portion provided on the inner peripheral side of the base portion,
A through-hole having a shape in which the width in the circumferential direction changes stepwise toward the outer side in the radial direction of the stator core is formed in the inner peripheral portion of the tip portion,
From the first intersection of the inner peripheral surface of the tip and a bisector that bisects the tip in the circumferential direction in a cross section perpendicular to the central axis direction, the boundary between the base and the tip The radial width to the second intersection with the bisector is the first width,
When the radial width from the first intersection to the third intersection between the radially outer end face of the through-hole and the bisector is the second width,
The stator core piece, wherein the second width is narrower than the first width.
A plurality of stator core pieces constituting an annular stator core,
The stator core piece is composed of a back yoke and teeth provided on the inner peripheral side of the back yoke,
The teeth include a base portion extending in the central axis direction from the circumferential center of the back yoke, and a tip portion provided on the inner peripheral side of the base portion,
A plurality of first through holes arranged in a circumferential direction and a second through hole provided between each of the plurality of first through holes are formed in the inner peripheral portion of the tip portion. Formed,
The width of the second through hole in the radial direction of the stator core is wider than the width of the first through hole in the radial direction,
From the first intersection of the inner peripheral surface of the tip and a bisector that bisects the tip in the circumferential direction in a cross section perpendicular to the central axis direction, the boundary between the base and the tip The radial width to the second intersection with the bisector is the first width,
When the width in the radial direction from the first intersection to the third intersection between the radially outer end face of the second through hole and the bisector is the second width,
The stator core piece, wherein the second width is narrower than the first width.
A plurality of stator core pieces constituting an annular stator core,
The stator core piece is composed of a back yoke and teeth provided on the inner peripheral side of the back yoke,
The teeth include a base portion extending in the central axis direction from the circumferential center of the back yoke, and a tip portion provided on the inner peripheral side of the base portion,
A first through hole and a second through hole provided between the first through hole and the back yoke are formed in the inner peripheral part of the tip part,
The circumferential width of the second through hole is narrower than the circumferential width of the first through hole,
From the first intersection of the inner peripheral surface of the tip and a bisector that bisects the tip in the circumferential direction in a cross section perpendicular to the central axis direction, the boundary between the base and the tip The radial width to the second intersection with the bisector is the first width,
When the width in the radial direction from the first intersection to the third intersection between the radially outer end face of the second through hole and the bisector is the second width,
The stator core piece, wherein the second width is narrower than the first width.
A plurality of stator core pieces constituting an annular stator core,
The stator core piece is composed of a back yoke and teeth provided on the inner peripheral side of the back yoke,
The teeth include a base portion extending in the central axis direction from the circumferential center of the back yoke, and a tip portion provided on the inner peripheral side of the base portion,
A groove is formed in the inner peripheral portion of the tip portion, and a through hole provided between the groove and the back yoke is formed apart from the groove,
The width in the circumferential direction of the groove is wider than the width in the circumferential direction of the through hole, or narrower than the width in the circumferential direction of the through hole,
From a first intersection of a virtual curve obtained by extending the curve of the inner peripheral surface of the tip to the groove and a bisector that bisects the tip in the circumferential direction in a cross section perpendicular to the central axis direction. The radial width to the second intersection of the boundary between the base and the tip and the bisector is the first width,
When the radial width from the first intersection to the third intersection between the radially outer end face of the through-hole and the bisector is the second width,
The stator core piece, wherein the second width is narrower than the first width.
A plurality of stator core pieces constituting an annular stator core,
The stator core piece is composed of a back yoke and teeth provided on the inner peripheral side of the back yoke,
The teeth include a base portion extending in the central axis direction from the circumferential center of the back yoke, and a tip portion provided on the inner peripheral side of the base portion,
In the inner peripheral portion of the tip portion, a plurality of grooves arranged in a circumferential direction are formed, and through holes provided between each of the plurality of grooves are formed,
From the first intersection of the inner peripheral surface of the tip and a bisector that bisects the tip in the circumferential direction in a cross section perpendicular to the central axis direction, the boundary between the base and the tip The radial width to the second intersection with the bisector is the first width,
When the radial width from the first intersection to the third intersection between the radially outer end face of the through-hole and the bisector is the second width,
The stator core piece, wherein the second width is narrower than the first width.
2. The stator core piece according to claim 1, wherein two or more grooves are formed in the tip portion from one end to the other end of the tip portion in the axial direction of the stator core.
Two or more sets of the first groove and the second groove are formed in the tip portion from one end to the other end of the tip portion in the axial direction of the stator core. The stator core piece according to claim 4, wherein
6. The stator core piece according to claim 5, wherein two or more through holes are formed in the tip portion from one end to the other end of the tip portion in the axial direction of the stator core. .
Two or more sets of the first through hole and the second through hole are formed in the tip portion from one end to the other end of the tip portion in the axial direction of the stator core. The stator core piece according to claim 6.
Two or more pairs of the first through hole and the second through hole are formed in the tip portion from one end to the other end of the tip portion in the axial direction of the stator core. The stator core piece according to claim 7, characterized in that
The two or more sets of the said groove | channel and the said through-hole are formed in the said front-end | tip part from the one end of the said front-end | tip part in the axial direction of the said stator core to the other end. The described stator core piece.
The two or more sets of the said groove | channel and the said through-hole are formed in the said front-end | tip part from the one end of the said front-end | tip part in the axial direction of the said stator core to the other end. The stator core piece according to 9.
A rotating electrical machine comprising a stator core configured by connecting a plurality of stator core pieces according to any one of claims 1 to 16 in a ring shape.