JP2024172940A - Stator and rotating electric machine - Google Patents

Abstract

To provide a stator capable of improving the output performance of a rotating electric machine.SOLUTION: A stator 20 of a rotating electric machine has a stator core 21 and a stator coil 22. The stator core 21 includes a cylindrical base 26 and multiple teeth 27 protruding radially from the base 26 in a circumferentially aligned manner. The stator coil 22 is wound around the teeth 27. The stator coil 22 has an inner coil 54 and an outer coil 55. The inner coil 54 and the outer coil 55 are provided on the teeth 27 in a parallel wound manner.SELECTED DRAWING: Figure 2

Description

The present invention relates to a stator and a rotating electric machine.

The rotating electric machine has a stator (see Patent Document 1). The stator of the rotating electric machine described in Patent Document 1 has a stator core, which is an iron core, and a stator coil provided on the stator core. The stator core has a cylindrical base (a so-called back yoke) and a number of teeth that protrude radially inward from the base and are aligned in the circumferential direction. The stator coil is wound around the teeth.

JP 2020-174496 A

In the rotating electric machine, in order to increase the maximum output, it is possible to increase the number of turns of the stator coil. However, simply increasing the number of turns of the stator coil makes it possible to increase the maximum output of the rotating electric machine, but it also increases the back electromotive force of the rotating electric machine. And when the back electromotive force of the rotating electric machine increases, this is one of the factors that reduces the output performance of the rotating electric machine.

The stator for solving the above problem is a rotating electric machine stator having a stator core with a cylindrical base and a number of teeth that protrude radially from the base in a circumferentially aligned manner, and a stator coil wound around the teeth, the stator coil including a number of coils wound in parallel.

The rotating electric machine for solving the above problem is a rotating electric machine equipped with a stator having a stator core with a cylindrical base and a plurality of teeth protruding radially from the base in a circumferentially aligned manner, and a stator coil wound around the teeth, the stator coil being configured to include a plurality of coils wound in parallel, and the rotating electric machine energizes all of the plurality of coils at low rotation speeds, and energizes only some of the plurality of coils at high rotation speeds.

When a rotating electric machine is rotating at low speed, a relatively large torque is required, but the back electromotive force, which increases in proportion to the rotation speed of the rotating electric machine, is less likely to be a problem. According to the above configuration, when the rotating electric machine is rotating at low speed, current is passed through all of the multiple coils wound in parallel, increasing the total number of turns of the coils in the current-passed state and obtaining a large torque output. Moreover, at this time, the back electromotive voltage of the rotating electric machine is lower than when the rotating electric machine is rotating at high speed, so the effect of the back electromotive voltage on the output performance of the rotating electric machine is suppressed. In this way, when the rotating electric machine is rotating at low speed, a large torque output can be obtained while suppressing the decrease in the output performance of the rotating electric machine caused by the back electromotive voltage.

When a rotating electric machine is rotating at high speeds, a large torque is no longer necessary, but the back electromotive force of the rotating electric machine is likely to become a problem. According to the above configuration, when the rotating electric machine is rotating at high speeds, by energizing only some of the multiple coils wound in parallel, the total number of turns of the energized coils can be reduced compared to when all of the multiple coils are energized. This allows the back electromotive voltage of the rotating electric machine to be lowered, thereby improving the output performance accordingly. Moreover, since a large torque is not necessary when the rotating electric machine is rotating at high speeds, a sufficient torque output can be obtained even though the total number of turns of the energized coils is reduced. In this way, when the rotating electric machine is rotating at high speeds, a decrease in output performance caused by the back electromotive voltage can be suppressed while obtaining sufficient torque.

Therefore, with the above configuration, it is possible to improve the output performance of the rotating electric machine.

1 is a side cross-sectional view of a rotating electric machine according to a first embodiment; FIG. 2 is a perspective view of a stator according to the first embodiment. FIG. 2 is an enlarged side view showing a tooth of the stator and its surroundings according to the first embodiment. 4 is a cross-sectional view of the stator of the first embodiment taken along line 4-4 in FIG. 3. FIG. 11 is an enlarged side cross-sectional view showing a tooth of a stator and its surroundings according to a second embodiment. 6 is a cross-sectional view of the teeth and their periphery taken along line 6-6 in FIG. 5 according to the second embodiment. FIG. 11 is a cross-sectional view of a stator tooth and its surroundings in another embodiment. FIG. 11 is an enlarged side cross-sectional view showing a tooth of a stator and its surroundings in another embodiment. 9 is a cross-sectional view of the tooth and its surroundings according to another embodiment taken along line 9-9 in FIG. 8.

First Embodiment
Hereinafter, a first embodiment of a stator and a rotating electric machine will be described with reference to FIGS. 1 to 4. FIG.

As shown in FIG. 1, the rotating electric machine 10 is a permanent magnet field type synchronous motor. The rotating electric machine 10 has a stator 20, a rotor 30, and a case 40 that houses the stator 20 and the rotor 30.

The stator 20 has a stator core 21 and a stator coil 22. The stator core 21 is an iron core. The stator core 21 has a generally cylindrical shape with the axis C as the central axis. The stator core 21 is fixed inside the case 40. The stator coil 22 is a winding. The stator coil 22 is wound around a central hole 23 in the stator core 21. Details of the stator 20 will be described later.

The rotor 30 has a rotor core 31 and a rotor shaft 32. The rotor core 31 is an iron core. The rotor core 31 is substantially cylindrical with the axis C as the central axis. The rotor shaft 32 is a rotating shaft. The rotor shaft 32 is integrated with the rotor core 31 while being inserted through the central hole 33 of the rotor core 31. The case 40 has a support hole 41 and a cylindrical support tube portion 43 that communicate between the inside and outside of the case 40. The support hole 41 and the support tube portion 43 function as bearings that rotatably support the rotor shaft 32. In this embodiment, the rotor shaft 32 is supported by the case 40 with one end of the rotor shaft 32 inserted into the support hole 41 and the other end inserted into the support tube portion 43.

<Stator>
The specific structure of the stator 20 will now be described.
2, the stator core 21 has a laminated structure in which a plurality of (e.g., several hundred) disk-shaped metal plates 24 each having a central hole are stacked together. The metal plates 24 are made of electromagnetic steel plates (more specifically, non-oriented silicon steel plates).

The stator core 21 has multiple (12 in this embodiment) slits 25. The multiple slits 25 are arranged so as to be evenly spaced in the circumferential direction of the stator core 21. Each slit 25 has a generally fan-shaped cross section and is shaped to penetrate the stator core 21 in the direction in which the axis C extends (hereinafter, the axis C direction). Each slit 25 opens on the inner peripheral surface of the stator core 21 and extends in the radial direction of the stator core 21.

In the stator 20, the roughly cylindrical portion on the outer periphery constitutes the base 26 (so-called back yoke). In the stator 20, the portions sandwiched between adjacent slits 25 constitute the teeth 27. The stator 20 has a plurality of teeth 27 (12 in this embodiment) arranged at equal intervals in the circumferential direction. Each tooth 27 protrudes radially inward from the base 26.

<Teeth>
As shown in Figures 2 to 4, in this embodiment, each of the teeth 27 has three teeth portions 50, 51, and 52 that are divided in a circumferentially aligned manner. More specifically, each of the teeth 27 has two slit portions 53. Each slit portion 53 starts from the inner peripheral surface of the tooth 27 and extends toward the outer periphery. Each slit portion 53 extends in the radial direction and in the direction of the axis C. The two slit portions 53 are provided at an interval in the circumferential direction. Each of the teeth 27 is divided into three teeth portions 50 to 52 by the two slit portions 53.

The three teeth 50-52 are arranged in the circumferential direction in the order of end teeth 50, central teeth 51, and end teeth 52. The central teeth 51 is arranged in the center of the arrangement direction of the three teeth 50-52 on the teeth 27. The central teeth 51 is also shorter in length in the axial direction C than the end teeth 50, 52. Specifically, both ends of the central teeth 51 in the axial direction C are positioned inward of the teeth 27 by the thickness of the stator coil 22 wound around the central teeth 51, relative to both ends of the end teeth 50, 52 in the axial direction C. This configuration is achieved by making the number of metal plates 24 (FIG. 4) constituting the central teeth 51 less than the number of metal plates 24 constituting the end teeth 50, 52. In this embodiment, the end teeth 50, 52 correspond to two of the three teeth excluding the central teeth.

<Stator coil>
The stator coil 22 is a concentrated winding type. The stator coil 22 is wound around the teeth 27. The stator coil 22 has an inner coil 54 and an outer coil 55. The inner coil 54 and the outer coil 55 are independent coils that are not connected to each other. The inner coil 54 and the outer coil 55 are wound around each of the multiple teeth 27 in such a manner that the winding ranges of the individual coils 54, 55 overlap in the radial direction. In this embodiment, when the inner coil 54 and the outer coil 55 are viewed from the direction of the axis C, the winding range of the inner coil 54 and the winding range of the outer coil 55 overlap. The inner coil 54 and the outer coil 55 are wound in parallel around each of the multiple teeth 27.

<Inner coil>
The inner coil 54 is wound only around the central teeth 51, which is located in the circumferential center of the three teeth 50 to 52. Specifically, the coil wire constituting the inner coil 54 is wound multiple times around the central teeth 51 to form a ring around the central teeth 51. The inner coil 54 is wound around the central teeth 51 so that the outer cross section of the arrangement range of the coil wire is substantially rectangular when the inner coil 54 is viewed from the radial inside (see FIG. 4).

In this embodiment, both ends of the central teeth 51 in the direction of axis C are positioned inward of the teeth 27 by the thickness of the stator coil 22 wound around the central teeth 51 relative to both ends of the end teeth 50, 52 in the direction of axis C. Therefore, when the inner coil 54 is wound around the central teeth 51, the outer circumferential surface of the inner coil 54 and both end faces of the end teeth 50, 52 in the direction of axis C are approximately flush with each other. In this embodiment, the inner coil 54 corresponds to the second coil.

<Outer coil>
The outer coil 55 is wound around the three teeth 50 to 52. Specifically, the coil wire constituting the outer coil 55 is wound multiple times around one tooth 27 having an end tooth 50, a central tooth 51, and an end tooth 52, so as to form a ring around the tooth 27. The outer coil 55 is wound around the entire tooth 27 so that the outer cross section of the coil wire arrangement range is substantially rectangular when the outer coil 55 is viewed from the radial inside (see FIG. 4). In this embodiment, the outer coil 55 corresponds to the first coil.

In this embodiment, the outer coil 55 is wound around the entire tooth 27 including the central teeth 51 in such a manner as to cover the outer periphery of the inner coil 54 wound around the central teeth 51. In this embodiment, the inner coil 54 and the outer coil 55 are arranged in an overlapping state on the central teeth 51, whereas only the outer coil 55 is arranged on the end teeth 50, 52 without overlapping the inner coil 54 and the outer coil 55.

<Operation control of rotating electrical machine>
In this embodiment, an electronic control device (not shown) is provided as a peripheral device of the rotating electric machine 10. The operation of the rotating electric machine 10 is controlled by this electronic control device.

Operation control of the rotating electric machine 10 is performed by switching between a first control mode in which current is passed through both the inner coil 54 and the outer coil 55, and a second control mode in which current is passed through only the inner coil 54. In more detail, when the rotating electric machine 10 is rotating at a low speed, the operation control of the rotating electric machine 10 is performed in the first control mode in which current is passed through both the inner coil 54 and the outer coil 55. On the other hand, when the rotating electric machine 10 is rotating at a relatively high speed, the operation control of the rotating electric machine 10 is performed in the second control mode in which current is passed through only the inner coil 54.

<Action>
The operation of the stator 20 and the rotating electrical machine 10 of this embodiment will be described below.
When the rotating electrical machine 10 rotates at low speed, a relatively large torque is required, but the back electromotive force that increases in proportion to the rotation speed of the rotating electrical machine 10 is unlikely to be a problem.

In this embodiment, when the rotating electric machine 10 is rotating at low speed, electricity is applied to both the inner coil 54 and the outer coil 55 wound in parallel around the teeth 27. This increases the total number of turns of the coils in the energized state, specifically the total number of turns (= W1 + W2) which is the sum of the number of turns W1 of the inner coil 54 and the number of turns W2 of the outer coil 55, and therefore a large torque output is obtained. Moreover, at this time, the back electromotive voltage of the rotating electric machine 10 is lower than when the rotating electric machine 10 is rotating at high speed, so the effect of the back electromotive voltage on the output performance of the rotating electric machine 10 is suppressed. In this way, when the rotating electric machine 10 is rotating at low speed, a large torque output is obtained while suppressing the decrease in the output performance of the rotating electric machine 10 caused by the back electromotive voltage.

When the rotating electrical machine 10 rotates at high speed, a large torque is no longer necessary, but the back electromotive force of the rotating electrical machine 10 is likely to become a problem.
In this embodiment, when the rotating electric machine 10 is rotating at high speed, only the inner coil 54 is energized. Therefore, compared with the case where both the inner coil 54 and the outer coil 55 are energized, the total number of turns of the energized coils (specifically, the number of turns W1 of the inner coil 54) can be reduced. This allows the back electromotive voltage of the rotating electric machine 10, which increases in proportion to the number of turns of the coil, to be reduced, thereby improving the output performance of the rotating electric machine 10 accordingly. Moreover, since a large torque is not required when the rotating electric machine 10 is rotating at high speed, a sufficient torque output can be obtained even though the total number of turns of the energized coils is reduced. In this way, when the rotating electric machine 10 is rotating at high speed, a sufficient torque output can be obtained while suppressing a decrease in output performance caused by the back electromotive voltage.

＜Effects＞
According to this embodiment, the following effects can be obtained.
(1-1) The inner coil 54 and the outer coil 55 are wound in parallel around one tooth 27. Therefore, when the rotating electric machine 10 is rotating at a low speed, a large torque output can be obtained while suppressing a decrease in the output performance of the rotating electric machine 10 caused by the back electromotive voltage. Also, when the rotating electric machine 10 is rotating at a high speed, a sufficient torque output can be obtained while suppressing a decrease in the output performance caused by the back electromotive voltage. Therefore, according to this embodiment, the output performance of the rotating electric machine 10 can be improved.

(1-2) In this embodiment, the inner coil 54 and the outer coil 55 are wound around each of the multiple teeth 27 in such a way that the winding ranges of the individual coils 54, 55 overlap in the radial direction. Therefore, the radial length of the teeth 27 can be made shorter than when the inner coil 54 and the outer coil 55 are wound around the teeth 27 in such a way that the winding ranges are aligned in the radial direction so as not to overlap. Therefore, the radial size of the stator 20 can be made smaller.

In this embodiment, the outer coil 55 is wound around the entire three teeth 50-52. The inner coil 54 is wound only around the central teeth 51, which is located in the center of the three teeth 50-52 in the circumferential direction. This configuration allows the shape of the portion of the tooth 27 around which the inner coil 54 is wound (specifically, the central teeth 51) and the shape of the portion around which the outer coil 55 is wound (specifically, the entire three teeth 50-52) to be set separately with a high degree of freedom. This allows the relationship between the output performance at low rotation speeds and the output performance at high rotation speeds of the rotating electric machine 10 to be adjusted and set with a high degree of freedom.

In this embodiment, the central teeth portion 51 is disposed in the center of the arrangement direction of the three teeth portions 50 to 52 on the teeth 27. This causes the central axis of the inner coil 54 wound around the central teeth portion 51 to coincide with the central axis of the outer coil 55 wound around the entire teeth 27. This allows the position where magnetic flux is generated on the teeth 27 to coincide between the first control mode in which current is passed only to the inner coil 54 and the second control mode in which current is passed to both the inner coil 54 and the outer coil 55. This allows smooth switching between the first and second control modes in the operation control of the rotating electric machine 10 while suppressing the occurrence of output steps.

(1-3) The length of the central teeth 51 in the direction of the axis C is shorter than that of the end teeth 50, 52. As a result, by winding the inner coil 54 around the central teeth 51, the outer peripheral surface of the inner coil 54 and both end surfaces of the end teeth 50, 52 in the direction of the axis C can be made substantially flush with each other. Therefore, by winding the outer coil 55 around the entire tooth 27 including the central teeth 51 in a manner that covers the outer periphery of the inner coil 54 wound around the central teeth 51, the outer cross section of the coil wire arrangement range can be arranged in a manner that is substantially rectangular. Therefore, according to this embodiment, although there is a mixture of overlapping portions where the inner coil 54 and the outer coil 55 are arranged to overlap with each other on the teeth 27 and non-overlapping portions where they are arranged not to overlap with each other, it is possible to prevent the overlapping portions from becoming thicker than the non-overlapping portions.

Second Embodiment
Hereinafter, a stator and a rotating electric machine according to the second embodiment will be described with reference to FIGS. 5 and 6, focusing on differences from the first embodiment.

This embodiment differs from the first embodiment only in the structure of the teeth and stator coil. The structure of the teeth and stator coil of this embodiment will be described below. Note that, below, the same components as those in the first embodiment will be denoted with the same reference numerals, and detailed description thereof will be omitted.

<Teeth>
As shown in Figures 5 and 6, the stator core 71 has a plurality of teeth 77. Note that Figures 5 and 6 show only one of the plurality of teeth 77. In the stator core 71 of this embodiment, a portion sandwiched between adjacent slits 25 constitutes the tooth 77. Each tooth 77 has a shape that protrudes radially inward (toward the lower side in Figure 5) from the base 26. In this embodiment, no slits extending radially and in the direction of the axis C are provided in the portion of the tooth 77 around which the stator coil 72 is wound. In this embodiment, the portion of the tooth 77 around which the stator coil 72 is wound has a substantially rectangular parallelepiped shape.

<Stator coil>
The stator coil 72 has an inner coil 84 and an outer coil 85. The inner coil 84 and the outer coil 85 are independent coils that are not connected to each other. The inner coil 84 and the outer coil 85 are wound around each of the multiple teeth 77 in a manner that is arranged radially so that the winding ranges of the individual coils 84 and 85 do not overlap. In this embodiment, when the inner coil 84 and the outer coil 85 are viewed from the axis C direction, the winding range of the inner coil 84 does not overlap with the winding range of the outer coil 85. In detail, the coil wire constituting the inner coil 84 is wound multiple times around the inner side (lower side in FIG. 5) of the tooth 77. The coil wire constituting the outer coil 85 is wound multiple times around the outer side (upper side in FIG. 5) of the tooth 77. The inner coil 84 and the outer coil 85 are wound in parallel around each of the multiple teeth 77.

<Operation control of rotating electrical machine>
In this embodiment, the operation control of the rotating electric machine 60 is performed by switching between a third control mode in which current is passed through both the inner coil 84 and the outer coil 85, and a fourth control mode in which current is passed through only the inner coil 84. In particular, when the rotating electric machine 60 is rotating at a low rotation speed, the operation control of the rotating electric machine 60 is performed in the third control mode in which current is passed through both the inner coil 84 and the outer coil 85. On the other hand, when the rotating electric machine 60 is rotating at a high rotation speed, the operation control of the rotating electric machine 60 is performed in the fourth control mode in which current is passed through only the inner coil 84.

<Action>
The operation of the stator 70 and the rotating electrical machine 60 of this embodiment will be described below.
In this embodiment, when the rotating electric machine 60 is rotating at a low speed, current is applied to both the inner coil 84 and the outer coil 85 wound in parallel. As a result, the total number of turns of the coils in the energized state, specifically, the total number of turns (=W3+W4) which is the sum of the number of turns W3 of the inner coil 84 and the number of turns W4 of the outer coil 85, is increased, and a large torque output is obtained. Moreover, at this time, the back electromotive voltage of the rotating electric machine 60 is lower than when the rotating electric machine 60 is rotating at a high speed, so that the effect of the back electromotive voltage on the output performance of the rotating electric machine 60 is suppressed. In this way, when the rotating electric machine 60 is rotating at a low speed, a large torque output is obtained while suppressing a decrease in the output performance of the rotating electric machine 60 caused by the back electromotive voltage.

In this embodiment, when the rotating electric machine 60 is rotating at high speed, only the inner coil 84 is energized. Therefore, compared to when both the inner coil 84 and the outer coil 85 are energized, the total number of turns of the energized coils (specifically, the number of turns W3 of the inner coil 84) can be reduced. This allows the back electromotive voltage of the rotating electric machine 60, which increases in proportion to the number of turns of the coil, to be reduced, thereby improving the output performance of the rotating electric machine 60 accordingly. Moreover, since a large torque is not required when the rotating electric machine 60 is rotating at high speed, a sufficient torque output can be obtained even though the total number of turns of the energized coils is reduced. In this way, when the rotating electric machine 60 is rotating at high speed, a sufficient torque output can be obtained while suppressing the decrease in output performance caused by the back electromotive voltage.

＜Effects＞
According to this embodiment, the following effects can be obtained.
(2-1) The inner coil 84 and the outer coil 85 are wound in parallel around one tooth 77. Therefore, when the rotating electric machine 60 is rotating at a low speed, a large torque output can be obtained while suppressing a decrease in the output performance of the rotating electric machine 60 caused by the back electromotive voltage. Furthermore, when the rotating electric machine 60 is rotating at a high speed, a sufficient torque output can be obtained while suppressing a decrease in the output performance caused by the back electromotive voltage. Therefore, according to this embodiment, the output performance of the rotating electric machine 60 can be improved.

(2-2) In this embodiment, the inner coil 84 and the outer coil 85 are wound around each of the multiple teeth 77 in a radially aligned manner so that the winding ranges of the individual coils 84, 85 do not overlap.

Therefore, compared to when the inner coil 84 and the outer coil 85 are wound around the teeth 77 with their winding ranges overlapping in the radial direction, the outer dimensions of the coils wound around the teeth 77 (specifically, the inner coil 84 and the outer coil 85) can be made smaller. This allows the size of the stator 70 in the direction of the axis C to be reduced.

<Example of change>
The above-described embodiments may be modified as follows: The above-described embodiments and the following modifications may be combined with each other to the extent that no technical contradiction occurs.

In the first embodiment, when the rotating electrical machine 10 rotates at high speed, instead of energizing only the inner coil 54, energizing only the outer coil 55 may be performed.
In the first embodiment, the length of the central tooth 51 in the direction of axis C may be the same as the length of the end teeth 50, 52 in the direction of axis C. Specifically, as shown in an example in Figure 7, the shapes of the three teeth 50 to 52 can be set so that the end face of the central tooth 51 in the direction of axis C and the end faces of the end teeth 50, 52 in the direction of axis C are flush with each other.

In the first embodiment, in order to provide multiple teeth portions on each tooth 27, instead of dividing each tooth 27 in the circumferential direction, each tooth 27 may be divided in the direction of the axis C.

Figures 8 and 9 show an example of such teeth. As shown in Figures 8 and 9, the tooth 100 is divided into three tooth portions 90 to 92 aligned in the direction of the axis C. More specifically, each of the multiple teeth 100 has two slit portions 93. Each slit portion 93 starts from the inner peripheral surface of the tooth 100 and extends outward. Each slit portion 93 extends along a plane perpendicular to the axis C. The two slit portions 93 are spaced apart in the direction of the axis C. Each of the multiple teeth 100 is divided into three tooth portions 90 to 92 by the two slit portions 93.

The inner coil 94 is wound around the central tooth 91, which is located in the center of the arrangement direction of the three tooth portions 90 to 92. The outer coil 95 is wound around the entire tooth 100. The inner coil 94 and the outer coil 95 are also wound around each of the multiple teeth 100 in such a manner that the winding ranges of the individual coils 94, 95 overlap in the radial direction. This configuration provides effects similar to those described in (1-1) and (1-2) above.

8 and 9, the central teeth 91 are shorter in circumferential length than the end teeth 90, 92. Specifically, both ends of the central teeth 91 in the circumferential direction are set back inward of the teeth 100 by the thickness of the inner coil 94 wound around the central teeth 91, relative to both ends of the end teeth 90, 92 in the circumferential direction.

According to this configuration, by winding the inner coil 94 around the central teeth 91, the outer peripheral surface of the inner coil 94 and both circumferential end surfaces of the end teeth 90, 92 can be made substantially flush with each other. Therefore, by winding the outer coil 95 around the entire tooth 100 including the central teeth 91 in a manner that covers the outer periphery of the inner coil 94 wound around the central teeth 91, the coil wire can be arranged in such a manner that the outer cross section of the coil wire arrangement range is substantially rectangular. Therefore, according to the above configuration, although there is a mixture of overlapping portions where the inner coil 94 and the outer coil 95 are arranged in an overlapping state with respect to the tooth 100 and non-overlapping portions where they are arranged in a non-overlapping state, it is possible to prevent the overlapping portions from becoming thicker than the non-overlapping portions.

- In the first embodiment, in order to provide multiple tooth portions on each tooth 27, in addition to dividing each tooth 27 in the circumferential direction, each tooth 27 may be divided in the axial direction C. In this case, for example, the inner coil 54 can be wound around a tooth portion that is located in the radial center of the multiple tooth portions and is also located in the center in the axial direction C. Also, the outer coil 55 can be wound around one entire tooth.

In the second embodiment, the inner coil 84 and the outer coil 85 may be wound around the teeth 77 in such a manner that at least a portion of the winding range of each of the coils 84, 85 overlaps in the radial direction.

- In each embodiment, three or more coils can be provided for one tooth 27, 77, 100 in a manner that the coils are wound in parallel. With such a configuration, the number of coils to be energized can be changed according to the rotation speed of the rotating electric machine 10, 60, thereby allowing for highly flexible operation control of the rotating electric machine 10, 60. For example, when three coils are provided for one tooth 27, 77, 100, it is possible to energize only one coil when the rotating electric machine 10, 60 is rotating at low speed, energize two coils when the rotating electric machine 10, 60 is rotating at medium speed, and energize three coils when the rotating electric machine 10, 60 is rotating at high speed.

The stator and rotating electric machine according to each of the above embodiments can be applied not only to stators and rotating electric machines having concentrated winding stator coils, but also to stators and rotating electric machines having distributed winding stator coils. In this case, the multiple coils constituting the stator coil can be arranged in a manner in which they are wound in parallel. Furthermore, when the rotating electric machine is rotating at low speed, current can be passed through all of the multiple coils, and when the rotating electric machine is rotating at high speed, current can be passed through only some of the multiple coils.

The stators and rotating electric machines according to the above embodiments can be applied to inner rotor type rotating electric machines and stators thereof, as well as outer rotor type rotating electric machines and stators thereof.

DESCRIPTION OF SYMBOLS 10...Rotating electric machine 20...Stator 21...Stator core 22...Stator coil 23...Central hole 24...Metal plate 25...Slit 26...Base 27...Teeth 30...Rotor 31...Rotor core 32...Rotor shaft 33...Central hole 40...Case 41...Support hole 43...Support cylinder portion 50...End teeth portion 51...Central teeth portion 52...End teeth portion 53...Slit portion 54...Inner coil 55...Outer coil 60...Rotating electric machine 70...Stator 71...Stator core 72...Stator coil 77...Teeth 84...Inner coil 85...Outer coil 90...End teeth 91...Central teeth 92...End teeth 93...Slit portion 94...Inner coil 95...Outer coil 100...Teeth

Claims (5)

A stator for a rotating electric machine includes a stator core having a cylindrical base and a plurality of teeth arranged in a circumferential direction and protruding radially from the base, and a stator coil wound around the teeth,
The stator coil is configured to include a plurality of coils wound in parallel. each of the plurality of teeth has a plurality of teeth portions divided in at least one of the axial direction and the circumferential direction of the stator core, and the plurality of coils are wound in a manner that the winding ranges of the individual coils overlap in the radial direction;
A first coil included in the plurality of coils is wound around the entirety of the plurality of teeth portions,
A second coil different from the first coil among the plurality of coils is wound around only a part of the plurality of teeth portions.
The stator according to claim 1 . the plurality of coils are two coils wound in parallel,
Each of the plurality of teeth has three teeth portions that are divided in a manner that is aligned in the circumferential direction, and the two coils are wound in a manner that the winding ranges of the individual coils overlap in the radial direction,
a first coil, which is one of the two coils, is wound around the three teeth portions,
a second coil, which is the other of the two coils, is wound only around a central tooth portion that is disposed in the center in the circumferential direction among the three teeth portions;
The stator according to claim 1 . The central teeth portion has a shorter length in the axial direction of the stator core than two of the three teeth portions other than the central teeth portion.
The stator according to claim 3 . A rotating electric machine including a stator having a stator core including a cylindrical base and a plurality of teeth arranged in a circumferential direction and protruding radially from the base, and a stator coil wound around the teeth,
The stator coil includes a plurality of coils wound in parallel,
In the rotating electric machine, current is passed through all of the plurality of coils at low rotation speeds, and current is passed through only some of the plurality of coils at high rotation speeds.

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