CN113039704B - Stator and motor using the same - Google Patents

Abstract

The stator (100) comprises: a plurality of teeth (10) provided on a yoke (20), insulators (50) respectively mounted on the respective teeth (10) of the plurality of teeth (10), and coils (40) formed of wires (41) having a rectangular cross section and wound around the respective insulators (50). The insulator (50) has a wire winding portion (52), and a first flange portion (51) and a second flange portion (53) that are respectively located at both ends of the wire winding portion (52). A plurality of protrusions (60) are provided at the corners (52 e 1-52 e 4) of the wire winding section (52). The protrusion (60) has a first surface (50 a) facing the first flange (51) and a second surface (60 b) facing the second flange (53) and having a convex curved surface.

Description

Stator and electric motor using the same

Technical Field

The present invention relates to a stator, in particular to a stator for winding a conducting wire with a rectangular cross section and a motor using the stator.

Background technique

In recent years, the demand for industrial and automotive electric motors has been increasing. Among them, the efficiency of the electric motor is required to be improved, and it is well known that increasing the slot fill factor of the coil arranged in the stator slot is effective in improving the efficiency of the electric motor. By increasing the slot fill factor of the coil, the loss caused by the current flowing in the coil can be suppressed when the motor is operating.

Until now, the following technology (for example, see patent documents 1 to 5) has been known to the public: by forming a coil with a so-called flat wire having a rectangular cross-section or by providing grooves on the surface of an insulating member for winding the wire to guide and hold the wire, the space factor of the coil in the slot is increased.

Patent Document 1: Japanese Patent Publication No. 2000-350420

Patent Document 2: Japanese Patent Publication No. 2007-267492

Patent Document 3: Japanese Patent Publication No. 2017-169310

Patent Document 4: Japanese Patent No. 4271495

Patent Document 5: Japanese Patent No. 5252807

Summary of the invention

Problem that the invention aims to solve

In order to increase the output of the electric motor, a so-called multi-layer winding coil is often used, that is, a coil formed by winding a conductive wire in layers in sequence starting from the surface of an insulating member.

However, when winding multiple layers of wires, for example, expansion occurs at the winding transition portion from winding the first layer of wires to winding the second layer of wires, and the wire winding irregularity is likely to occur. In particular, when a multi-layer winding coil is formed using a flat wire, since the planes of the first layer of wires and the second layer of wires are wound on the insulating member in contact with each other, the wires are likely to slide on the contact surface, and the above-mentioned irregular winding phenomenon is more likely to occur.

If the wire winding is not neat, the coil slot space factor will be reduced and the efficiency of the motor cannot be fully improved.

The present invention is made to solve the above problems and aims to provide a stator and a motor using the stator, which can suppress the uneven winding phenomenon in the wire winding conversion part and improve the wire slot space factor of the coil.

Solutions for solving problems

To achieve the above-mentioned object, the stator involved in the present invention includes: an annular yoke, a plurality of teeth arranged in the circumferential direction of the yoke with a predetermined interval therebetween and extending from the inner circumference of the yoke in the radial direction of the yoke, a plurality of insulating members mounted on each of the plurality of teeth, and a plurality of coils composed of a conductive wire having a rectangular cross section and wound on each of the plurality of insulating members. The insulating member has a conductive wire winding portion, a first flange portion, and a second flange portion, the conductive wire winding portion being cylindrical and having the conductive wire wound thereon, the first flange portion being arranged at one end of the conductive wire winding portion and having a conductive wire guide groove for guiding the conductive wire toward the conductive wire winding portion, and the second flange portion being arranged at the other end of the conductive wire winding portion. The conductive wire winding portion has a first end face, a second end face, a first side face, a second side face, and a plurality of protrusions. The first end face is connected to the bottom face of the wire guide groove; the second end face is opposite to the first end face in the axial direction of the stator; the first side face and the second side face are both arranged from the circumferential end edge of the first end face to the circumferential end edge of the second end face, and the first side face and the second side face are opposite to each other in the circumferential direction; the plurality of protrusions are arranged at least at the corners of the wire winding portion, and are used to wind the wire on the first end face at a predetermined angle relative to the direction orthogonal to the radial direction. The plurality of protrusions are spaced apart from each other at predetermined intervals in the radial direction, and the protrusions have a first face opposite to the first flange portion and a second face opposite to the second flange portion, and at least one of the first face and the second face has a convex curved surface.

According to this configuration, the conducting wire having a rectangular cross section can be stably wound neatly and in multiple layers around the insulating member.

The electric motor according to the present invention is characterized by including at least the stator and a rotor provided at a predetermined interval from the stator.

According to this configuration, the conducting wires are neatly wound around the insulator in multiple layers, so that the coil slot space factor can be increased, thereby realizing a high-efficiency motor.

Effects of the Invention

According to the stator of the present invention, a conducting wire with a rectangular cross section can be stably wound neatly and in multiple layers on an insulating member; according to the motor of the present invention, the coil slot space factor can be increased, thereby realizing a high-efficiency motor.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a cross-sectional view of a motor according to a first embodiment of the present invention;

FIG2 is a schematic diagram of an insulating member;

Fig. 3 is a schematic diagram of the main parts of the stator;

FIG4 is a schematic diagram of the main part of the stator as seen from the axial upper end;

FIG5 is a cross-sectional view taken along line V-V in FIG3 ;

6 is a schematic diagram illustrating the relationship between the inclination angle of the conductor and the radial direction and the distance between radially adjacent conductors;

7 is a schematic diagram illustrating the relationship between the recess angle of the slot and the inclination angle of the wire and the radial direction;

FIG8 is a diagram showing the structure of a winding device;

9 is a process diagram showing the process of winding the wire around the insulating member;

10A is a schematic diagram showing the arrangement of the wire on the wire winding portion when no protrusion is provided;

10B is a schematic diagram showing the arrangement of the wire on the wire winding portion when the protrusion is provided;

FIG11 is a schematic diagram of another insulating member;

12 is a schematic diagram of a first insulating member according to a modification example;

13 is a schematic diagram of a second insulating member according to a modification example;

14 is a schematic diagram of a third insulating member according to a modification example;

15 is a schematic diagram of a fourth insulating member according to a modification example;

16 is a schematic diagram of an insulating member according to a second embodiment of the present invention;

FIG17 is a schematic diagram of the main part of the stator as seen from the axial lower end;

18A is a schematic cross-sectional view of a main portion of a stator according to a third embodiment of the present invention;

Fig. 18B is a schematic cross-sectional view of a main portion of a stator for comparison;

19A is a schematic cross-sectional view of a main portion of a stator according to a fourth embodiment of the present invention;

Fig. 19B is a schematic cross-sectional view of a main portion of a stator for comparison;

FIG20 is a schematic cross-sectional view of a main portion of a stator filled with a heat dissipating material.

Detailed ways

The following preferred embodiments are merely examples of the present invention and are not intended to limit the present invention, its application objects or its uses.

(First Embodiment)

[Electric Motor Structure]

FIG1 is a cross-sectional view of the motor involved in the present embodiment. It should be noted that, in the following description, the radial direction of the motor 1000 and the stator 100 is referred to as the "radial direction", the peripheral direction is referred to as the "circumferential direction", and the direction in which the output shaft 210 of the motor 1000 extends (the direction perpendicular to the paper surface in FIG1 ) is referred to as the "axial direction". Since the output shaft 210 is substantially consistent with the central axis of the stator 100, the direction in which the central axis of the stator 100 extends is referred to as the "axial direction". In terms of the radial direction, the central side of the stator 100 is referred to as the radial inner side, and the peripheral side of the stator 100 is referred to as the radial outer side.

The motor 1000 has a stator 100 and a rotor 200. It should be noted that the motor 1000 also has components other than the stator 100 and the rotor 200, such as a motor housing, a bearing supporting an output shaft 210, etc., but for the sake of convenience, the illustration and description thereof are omitted. The motor 1000 is a so-called inner rotor type motor, but is not particularly limited thereto, and may also be an outer rotor type motor.

The stator 100 includes an annular yoke 20, a plurality of teeth 10 connected to the inner circumference of the yoke 20 and arranged at equal intervals along the inner circumference, a plurality of insulators 50 (see FIG. 2 ) attached to each of the plurality of teeth 10, a plurality of slots 30 constituting spaces between the plurality of teeth 10 adjacent in the circumferential direction, and a plurality of coils 40 received in each of the plurality of slots 30. The stator 100 is arranged radially outside the rotor 200 with a certain interval therebetween.

In the following description, when the number is singular, it is referred to as one tooth (Tooth) 10, and when the number is plural, it is referred to as a plurality of teeth (Teeth) 10. When it is possible to refer to either the singular or the plural, it is referred to as a tooth 10.

The tooth 10 is formed by laminating electromagnetic steel sheets containing silicon or the like and then performing a punching process. The yoke 20 is an annular component formed by connecting a plurality of split yokes 21 in the circumferential direction. Like the tooth 10, the split yoke 21 is formed by laminating electromagnetic steel sheets containing silicon or the like and then performing a punching process. Each split yoke 21 is provided with one tooth 10.

The coil 40 is a component formed by winding a conductive wire 41 (refer to FIG. 3 ) having a rectangular cross section. The coil 40 is mounted on a tooth 10 with an insulating member 50 sandwiched therebetween and is housed in the slot 30. The insulating member 50 is a component formed of an insulating material and mounted on a tooth 10 and a split yoke 21, and electrically separates the coil 40 from the tooth 10 and the yoke 20. The structure of the insulating member 50 will be described in detail later. It should be noted that in the present embodiment, the coil 40 is referred to as coils U1 to U4, coils V1 to V4, and coils W1 to W4, respectively, according to the phase of the current flowing through the coil 40. The conductive wire 41 constituting the coil 40 is neatly and multi-layeredly wound on the insulating member 50 mounted on a tooth 10 (refer to FIG. 3 ).

The rotor 200 has an output shaft 210 and a magnet 220. The output shaft 210 is arranged at the axis; the magnet 220 is opposite to the stator 100, and the N pole and the S pole are alternately arranged in the outer peripheral direction of the output shaft 210. It should be noted that the material, shape, and material of the magnet 220 can be appropriately changed according to the output of the motor 1000.

Coils U1 to U4, coils V1 to V4, and coils W1 to W4 are connected in series, respectively, and currents of three phases, namely, U phase, V phase, and W phase, which have a phase difference of 120° in electrical angle, are supplied to coils U1 to U4, coils V1 to V4, and coils W1 to W4, respectively, and coils U1 to U4, coils V1 to V4, and coils W1 to W4 are magnetized, thereby generating a rotating magnetic field in the stator 100. The rotating magnetic field interacts with the magnetic field generated by the magnet 220 provided in the rotor 200 to generate torque in the rotor 200, and the output shaft 210 is supported by a bearing (not shown) to rotate.

[Constitution of insulating member]

FIG2 is a schematic diagram of the insulating member involved in this embodiment. It should be noted that, for the sake of convenience, the insulating member 50 is shown in a simplified shape. FIG2 also shows an enlarged view of the portion surrounded by a dotted line; FIG2 shows the shape of the insulating member 50 after a layer of the wire 41 is wound around it with a dotted line.

As shown in FIG2 , the insulating member 50 has a wire winding portion 52, a first flange portion 51, and a second flange portion 53. The wire winding portion 52 is for winding the wire 41; the first flange portion 51 is disposed at the radially outer end of the wire winding portion 52 and has a wire guide groove 51a; and the second flange portion 53 is disposed at the radially inner end of the wire winding portion 52.

The wire 41 is guided toward the wire winding portion 52 through the wire guide groove 51a. It should be noted that the shape of the wire guide groove 51a is not limited to the shape shown in FIG. 2. For example, it can also be a shape inclined with respect to the radial direction (refer to FIG. 4). The latter can reduce the guide angle δ of the wire 41 (refer to FIG. 4), and it is easy to suppress the uneven winding of the wire 41. It should be noted that the insulating member 50 is installed on one tooth 10 in order to cover a part of the split yoke 21 with the first flange portion 51.

The wire winding portion 52 is prism-shaped when viewed along the cross-sectional direction, and has a first end face 52a and a second end face 52b. The first end face 52a is connected to the bottom surface of the wire guide groove 51a; the second end face 52b is opposite to the first end face 52a in the axial direction. The wire winding portion 52 also has a first side face 52c and a second side face 52d. The first side face 52c extends along the axial direction from one circumferential end edge of the first end face 52a to one circumferential end edge of the second end face 52b; the second side face 52d extends along the axial direction from the other circumferential end edge of the first end face 52a to the other circumferential end edge of the second end face 52b (refer to Figure 3). The first side face 52c and the second side face 52d are opposite to each other in the circumferential direction.

The wire winding portion 52 has four corners 52e1 to 52e4. The four corners 52e1 to 52e4 are composed of a first corner 52e1 located between the first end face 52a and the first side face 52c, a second corner 52e2 located between the first side face 52c and the second end face 52b, a third corner 52e3 located between the second end face 52b and the second side face 52d, and a fourth corner 52e4 located between the second side face 52d and the first end face 52a.

A plurality of protrusions 60 are provided at each of the four corners 52e1 to 52e4. The plurality of protrusions 60 are provided so as to reach the adjacent surfaces from each of the corners 52e1 to 52e4. For example, the protrusions 60 provided at the first corner 52e1 are provided so as to reach the first end surface 52a and the first side surface 52c; and the protrusions 60 provided at the third corner 52e3 are provided so as to reach the second end surface 52b and the second side surface 52d. The plurality of protrusions 60 provided at each of the corners 52e1 to 52e4 are provided with intervals Z in the radial direction.

The protrusion 60 has a first surface 60a facing the first flange portion 51 and a second surface 60b facing the second flange portion 53. The first surface 60a is a substantially flat surface, while the second surface 60b is a curved surface convexly directed radially inward.

[Composition of the main parts of the stator]

Fig. 3 is a schematic diagram of the main part of the stator involved in this embodiment, Fig. (a) is a stereoscopic view seen from the axial upper end, and Fig. (b) is a stereoscopic view seen from the axial lower end. Fig. 4 is a schematic diagram of the main part of the stator seen from the axial upper end. Fig. 5 is a cross-sectional view taken along the V-V line in Fig. 3.

It should be noted that, for the sake of convenience, FIG3 shows a state where the wire 41 is wound around the wire winding portion 52 and is wound halfway through the third layer, and FIG4 shows a state where the wire 41 is wound around the wire winding portion 52 and is wound halfway through the first layer. For the sake of convenience, in FIG4, the shape of the wire guide groove 51a is inclined at a guide angle δ relative to a direction orthogonal to the radial direction when viewed from the axial direction.

The protrusion 60 is omitted in FIG5 . It should be noted that the cross-sectional shape including the protrusion 60 is shown in FIG10B described later. The arrow directions shown in FIG5 indicate the winding order of each layer of the wire 41. For example, the first layer wire 411 is wound from the first flange portion 51 toward the second flange portion 53, and the second layer wire 412 is wound from the second flange portion 53 toward the first flange portion 51.

It should be noted that in the following description, when the wire 41 has been wound around the wire winding portion 52 for n layers (n is an integer greater than or equal to 2), the portion from winding the wire 41 of the i-1th layer (i is an integer greater than or equal to 2, and i≤n) to winding the wire 41 of the i-th layer is referred to as the intersection 4i (intersection 42, 43, . . . , 4i). In the present embodiment, the wire 41 is wound so that the intersection 4i is located on the first end surface 52a. The wire 41 is wound neatly and in multiple layers around the wire winding portion 52 of the insulating member 50.

As shown in FIG. 3 (a) and FIG. 4, the first-layer wire 411 guided from the wire guide groove 51a to the first end face 52a is wound around the first end face 52a at a predetermined crossing angle ε (see FIG. 4) with respect to the direction perpendicular to the radial direction. At the radial inner end of the wire winding portion 52, the second-layer wire 412 bypassed from the first-layer wire 411 is wound around the first end face 52a at an angle different from the crossing angle ε. At the radial outer end of the wire winding portion 52, the third-layer wire 413 bypassed from the second-layer wire 412 is wound around the first end face 52a at an angle substantially the same as the crossing angle ε.

On the other hand, as shown in Figure 3 (b), the first layer of wires to the third layer of wires 411 to 413 wound on the wire winding portion 52 are parallel to the end face located on the radial inner side of the first flange portion 51 (hereinafter referred to as the inner face 51b of the first flange portion 51) at the second end face 52b, the first side face 52c and the second side face 52d.

The first layer wire 411 is positioned by a plurality of protrusions 60 provided at each corner 52e1 to 52e4 and is held on the surface (see FIGS. 10A and 10B ) of the wire winding portion 52. The first layer wire 411 is wound around the surface of the wire winding portion 52, i.e., the first end face 52a, the second end face 52b, the first side face 52c, and the second side face 52d, at a predetermined angle θ to the radial direction.

On the other hand, as shown in FIG5 , the second and subsequent layers of the conductor 41 are supported by the end face 41b of the conductor 41 of the lower layer and are wound neatly. The second and subsequent layers of the conductor 41 are also wound on the conductor 41 of the lower layer at a predetermined angle θ with respect to the radial direction, similarly to the first layer of the conductor 411. It should be noted that in FIG5 , the surface of the conductor 41 that forms an angle θ with respect to the radial direction is referred to as a plane 41a, and the surface of the conductor 41 that is orthogonal to the plane 41a is referred to as an end face 41b, and the same is used in the following description.

As shown in FIGS. 3 to 5 , in order to wind the wires 41 neatly and in multiple layers on the wire winding portion 52 , it is particularly necessary to prevent the first layer of the wires 411 from being wound unevenly.

This is further described. The first layer wire 411 guided from the wire guide groove 51a to the first end surface 52a is wound, and as a result, the first layer wire 411 is pressed against the inner surface 51b of the first flange portion 51. Therefore, as shown in FIG. 4, the first layer wire 411 forms a curved portion that expands toward the radial inside at the terminal portion of the wire guide groove 51a.

When the curvature radius of the curved portion is R, if the curvature radius R becomes smaller, the deformation amount of the first layer wire 411 at the terminal portion of the wire guide groove 51a, that is, the expansion amount toward the radial inner side, will become larger, which is likely to cause uneven winding. Therefore, it is necessary to make the curvature radius R as large as possible.

Therefore, by setting the winding angle of the first layer wire 411 so that the guide angle δ and the crossing angle ε shown in Figure 4 satisfy the relationship of the following formula (1), the curvature radius R can be increased, thereby preventing the wire 41, especially the first layer wire 411, from being wound unevenly.

ε≤δ……(1)

Fig. 6 is a schematic diagram for explaining the relationship between the inclination angle of the conductor and the radial direction and the distance between radially adjacent conductors, wherein Fig. (a) shows the theoretical limit when radially adjacent conductors overlap each other, and Figs. (b) and (c) show the case where the end faces of radially adjacent conductors partially overlap each other. It should be noted that in Fig. (c), the corner of the conductor 41 is an arc-shaped cross-section with a predetermined radius.

Fig. 7 is a schematic diagram for explaining the relationship between the recess angle of the slot and the inclination angle of the wire with respect to the radial direction. It should be noted that, for the sake of convenience, the insulating member 50 is omitted from Fig. 6 and Fig. 7. Fig. 7 also shows an enlarged view of a portion surrounded by a dotted line.

When the wires 41 wound around the insulating member 50 are in contact with each other in the radial direction, as shown in FIG6(a), the maximum value θmax of the inclination angle θ of the wires 41 to the radial direction is expressed by equation (2). It should be noted that FIG6(a) to FIG6(c) all show the first layer of wires 411.

θmax＝tan ^-1 (Y/X)……(2)

Here, X represents the long side of the wire 411 viewed along the cross-sectional direction, and Y represents the short side of the wire 411 viewed along the cross-sectional direction; X is equivalent to one side of the plane 41a, and Y is equivalent to one side of the end face 41b.

At this time, the maximum value Zmax of the interval Z between the radially adjacent conductive wires 411 is expressed by the following equation (3). It should be noted that the interval Z corresponds to the interval Z between the protrusions 60 shown in FIG.

Zmax＝X/cos(θmax)……(3)

On the other hand, as shown in Figures (b) and (c) of Figure 6, when the conductors 411 overlap each other with their short sides for a specified length, the above-mentioned inclination angle θ can be expressed by the following formula (4), and the spacing Z can be expressed by the following formula (5).

θ＝θmax×α＝tan ^-1 (Y/X)(100-α)……(4)

Z＝Zmax×β＝(X/cosθ)×(β/100)……(5)

Here, the variable α represents the overlap (%) of the short sides of the conductor 41, and the variable β represents the margin (%) of the pitch Z. The variables α and β can be appropriately changed according to the cross-sectional shape of the conductor 41, the material and state of the surface insulating film (not shown) of the conductor 41, etc. Furthermore, the variables α and β can be changed within the ranges represented by equations (6) and (7), respectively.

0＜α(%)＜100……(6)

β(%)＞100……(7)

It should be noted that when the wires 41 are in contact with each other with their short sides overlapping, the variable α is preferably about 20% or more in order for the wires 41 to be stably held by the wire winding portion 52. Similarly, the variable β is preferably about 103%.

It should be noted that, although FIG. 6 shows the case where the first-layer wire 411 is in radial contact, the relationships shown in equations (2) to (7) are also valid in the following cases other than this. For example, the case where the first-layer wire 411 and the second-layer wire 412 are in radial contact so that their short sides partially overlap each other, and the case where the second-layer wire 412 and the third-layer wire 413 are in radial contact so that their short sides partially overlap each other.

The dot-dash line in FIG7 shows the arrangement of the wire 41 wound according to the winding sequence in the prior art, which is equivalent to the case where the wire 41 is wound around the wire winding portion 52 without the inclination angle θ. In this case, the volume of the non-effective space in the uppermost layer of the coil 40 where the wire 41 is not arranged may increase, or the wire 41 may protrude from the slot 30.

On the other hand, as shown in FIG. 7 , by winding the wire at the above-mentioned inclination angle θ with respect to the radial direction, the volume of the above-mentioned non-effective space can be reduced. Moreover, it is preferable that the inclination angle θ is less than the setback angle θcore of the slot 30. Here, θcore corresponds to the angle formed by the virtual plane and the first side surface 52c or the second side surface 52d of the wire winding portion 52, and the virtual plane passes through the side surface of the protrusion 10a provided at the radial inner end of one tooth 10 and protruding in the circumferential direction and the side surface of the split yoke 21. For example, when the inclination angle θ is less than the setback angle θcore with respect to the second side surface 52d, the uppermost wire 411 of the wire 41 wound on the insulating member 50 in multiple layers can be accommodated in the corresponding slot 30 without protruding in the circumferential direction, so that the slot occupancy factor of the coil 40 can be maintained high. However, in consideration of the crossing angle ε, the interval Z between the protrusions 60, etc., the inclination angle θ only needs to be less than the setback angle θcore.

[Wire winding method]

FIG8 shows the structure of the winding device, and FIG9 is a process diagram showing the process of winding the wire around the insulating member. It should be noted that, for the sake of convenience, FIG8 only shows a simplified view of the main part of the winding device. The protrusion 60 provided on the insulating member 50 is omitted. The winding device is omitted in FIG9.

As shown in FIG8 , the wire 41 shown in this embodiment can be wound around the insulating member 50 by a conventional workpiece rotating winding method. That is, a tooth 10 on which the insulating member 50 is mounted is placed on the stator support 2100, and the wire 41 is guided from the wire guide groove 51a toward the wire winding portion 52, and the front end of the wire 41 is grasped by the nozzle 2200. It should be noted that the stator support 2100 has a rotation axis (not shown) so that the rotation axis is consistent with the radial center line of the insulating member 50.

In this state, the stator support 2100 is rotated around its rotation axis and the nozzle 2200 is moved relative to the stator support 2100, and the wire 41 is wound around the insulating member 50. It should be noted that the nozzle 2200 moves the front end of the wire 41 so that the first layer of wire 411 is held by the protrusion 60 and the first layer of wire 411 is wound around the first end surface 52a at the crossing angle ε. When the front end of the wire 41 is moved, it is ensured that the first layer of wire 411 and the inner surface 51b of the first flange portion 51 move in parallel within the range of the second end surface 52b and the first side surface 52c and the second side surface 52d. After the second layer of wire 412, the nozzle 2200 moves the front end of the wire 41 to achieve the winding shape shown in FIG. 9.

By winding the wire 41 around the insulating member 50 in this way, the first layer wire 411 is neatly wound around the wire winding portion 52, as shown in Figure 9 (a). Next, at the intersection 42, the winding of the first layer wire 411 is changed to the winding of the second layer wire 412, and the second layer wire 412 is wound on the first end face 52a substantially symmetrically with the first layer wire 411 with respect to the radial direction (Figure 9 (b)). The second layer wire 412 is wound to the radially outer end of the wire winding portion 52 (Figure 9 (c)), and the winding of the third layer wire 413 is changed at the intersection 43 (Figure 9 (d)). The third layer wire 413 is wound on the first end face 52a at an angle substantially the same as the crossing angle ε.

Although not shown in the figure, in FIG9 (c), the first-layer wire 411 is supported by a plurality of protrusions 60 provided on the corners 52e1 to 52e4 of the wire winding portion 52, and is wound on the surface of the wire winding portion 52 at an angle θ to the radial direction. The second-layer wire 412 is supported by the end face 41b of the first-layer wire 411, and is wound on the first-layer wire 411 at an angle θ to the radial direction. Similarly, the third-layer wire 413 is supported by the end face 41b of the second-layer wire 412, and is wound on the second-layer wire 412 at an angle θ to the radial direction.

It should be noted that in this embodiment, the winding method using the nozzle winding is described as an example, but the winding method using the nozzle winding may be replaced by a winding method using a roller, hook or cam to guide the wire 41. As described above, the workpiece rotating winding method is suitable for winding the wire 41 having a non-circular cross-sectional shape, but if the undesirable phenomenon such as the distortion of the wire 41 can be eliminated, the workpiece fixed winding method may be used to install the wire 41 by winding.

[Effects, etc.]

As described above, the stator 100 involved in this embodiment includes: an annular yoke 20, a plurality of teeth 10 arranged in the circumferential direction of the yoke 20 with specified intervals between each other and extending from the inner circumference of the yoke 20 along the radial direction of the yoke 20, a plurality of insulating members 50 respectively installed on each of the plurality of teeth 10, and a plurality of coils 40 composed of a conductive wire 41 with a rectangular cross-section and respectively wound on each of the plurality of insulating members 50.

The insulating member 50 includes a wire winding portion 52, a first flange portion 51, and a second flange portion 53. The wire winding portion 52 is cylindrical and is wound with the wire 41; the first flange portion 51 is provided at the radially outer end of the wire winding portion 52 and has a wire guide groove 51a for guiding the wire 41 toward the wire winding portion 52; and the second flange portion 53 is provided at the radially inner end of the wire winding portion 52.

The wire winding portion 52 has a first end face 52a, a second end face 52b, a first side face 52c, and a second side face 52d. The first end face 52a is connected to the bottom face of the wire guide groove 51a; the second end face 52b is opposite to the first end face 52a in the axial direction of the stator 100; the first side face 52c and the second side face 52d are both arranged from the circumferential end edge of the first end face 52a to the circumferential end edge of the second end face 52b, and the first side face 52c and the second side face 52d are opposite to each other in the circumferential direction. The wire winding portion 52 also has a plurality of protrusions 60, which are arranged at the corners 52e1 to 52e4 of the wire winding portion 52, and are used to wind the wire 41 on the first end face 52a at a predetermined crossing angle ε relative to the direction orthogonal to the radial direction.

The plurality of protrusions 60 are spaced apart from each other by intervals Z in the radial direction, and each protrusion 60 has a first surface 60a opposite to the first flange portion 51 and a second surface 60b opposite to the second flange portion 53. The first surface 60a is a flat surface, and the second surface 60b is a curved surface convex toward the radial inside.

By configuring the stator 100 in this manner, the so-called flat wire conductors 41 having a rectangular cross section can be stably wound neatly and in multiple layers around the insulating member 50. This will be further described with reference to the drawings.

FIG. 10A is a schematic diagram showing the arrangement of the wires on the wire winding portion when no protrusion is provided; FIG. 10B is a schematic diagram showing the arrangement of the wires on the wire winding portion when the protrusion is provided. It should be noted that FIG. 10A and FIG. 10B show enlarged views of the portion surrounded by the dotted line. FIG. 10A and FIG. 10B show only the first layer of wires 411 in the wires 41. The dotted line indicates the actual position of the wire 41, and the dotted line indicates the position where the wire 41 should originally be wound.

As shown in FIG10A , in the process of winding the first-layer wire 411 guided from the wire guide groove 51a on the wire winding portion 52, the first-layer wire 411 receives a force directed radially inward from the first-layer wire 411 adjacent in the radial direction. In the case where the protrusion 60 is not provided on the wire winding portion 52, there is no mechanism for supporting the first-layer wire 411 in the radial direction, so the first-layer wire 411 is wound on the wire winding portion 52 deviating from the original position. As a result, the winding irregularity occurs, and the first-layer wire 411 is not wound neatly on the wire winding portion 52. In addition, if the winding irregularity occurs on the first-layer wire 411, the second and subsequent layers of the wire 41 wound thereon in sequence cannot be wound neatly, resulting in a decrease in the slot space factor of the coil 40.

On the other hand, as shown in FIG10B , according to the present embodiment, by providing a plurality of protrusions 60 at each corner 52e1 to 52e4 of the wire winding portion 52, the first-layer wire 411 can be supported in the radial direction. Since the plurality of protrusions 60 are spaced apart from each other in the radial direction, the first-layer wire 411 is held on the surface of the wire winding portion 52 in a neatly wound state. Although not shown in FIG10B , the second-layer wire 412 is neatly wound around the first-layer wire 411 by being supported by the end surface 41b of the first-layer wire 411, and the third and subsequent layers of wire 41 are also neatly wound around the insulating member 50, so that the neatly wound coil 40 in multiple layers can be stably realized.

As shown in FIG. 10B , the first surface 60a of the protrusion 60 is a very flat plane, while the second surface 60b of the protrusion 60 is a curved surface that is convex toward the radial inner side. By configuring the protrusion 60 in this way, the end surface 41b of the first layer wire 411 is stably held on the first surface 60a. Even when the thickness of the wire 41, in this case, the long side X and the short side Y of the first layer wire 411 deviate from the design value and the inclination angle θ changes, the first layer wire 411 can reliably contact the second surface 60b because the second surface 60b is a curved surface. In this way, the first layer wire 411 is held on the surface of the wire winding portion 52 in a state of being positioned at a predetermined position and wound neatly.

By making the second surface 60b a convex curved surface, the protrusion 60 can be easily separated from the mold when the insulating member 50 is integrally molded using a mold (not shown). In this way, it is possible to suppress the increase in the manufacturing cost of the insulating member 50, which is caused by the use of a special mold release agent that makes it easy for the protrusion 60 to be separated, or the generation of defective insulating members 50 due to the protrusion 60 being damaged when the protrusion 60 is separated from the mold.

The first layer of the wire 411 wound on the wire winding portion 52 is supported by the plurality of protrusions 60 and wound on the first end surface 52a at a crossing angle ε, and is wound on the surface of the wire winding portion 52 at an inclination angle θ with respect to the radial direction.

The wire 41 wound on the wire winding portion 52 has n layers (n is an integer greater than or equal to 2), and the wire 41 of the i-th layer (i is an integer greater than or equal to 2, and i≤n) is wound around the wire 41 of the i-1th layer at the first end surface 52a, and is wound around the wire 41 of the i-1th layer at an angle different from the crossing angle ε. The wire 41 of the i-th layer is supported by the end surface 41b of the wire 41 of the i-1th layer, and is wound around the wire 41 of the i-1th layer at an inclined angle θ with respect to the radial direction.

By winding the conductor 41 around the conductor winding portion 52 in this manner, the second-layer conductor 412 is neatly wound around the first-layer conductor 411, supported by the end face 41b of the first-layer conductor 411 neatly wound at an angle θ to the radial direction and held by the plurality of protrusions 60, without causing irregular winding at the intersection 42. Similarly, the i-th-layer conductor 41 is neatly wound around the i-1-th-layer conductor 41, supported by the end face 41b of the neatly wound i-1-th-layer conductor 41, without causing irregular winding at the intersection 4i. As described above, the coil 40 neatly and multi-layered wound around the insulating member 50 can be stably realized.

The protrusion 60 arranged on the corner 52e1 between the first end face 52a and the first side face 52c and the protrusion 60 arranged on the corner 52e2 between the first side face 52c and the second end face 52b, respectively, have their respective convex curved surfaces, i.e., second surfaces 60b facing the same direction, in this case facing radially inward.

In this way, the position of the intersection portion 4i can be reliably determined on the first end surface 52a.

The electric motor 1000 according to the present embodiment includes at least a stator 100 and a rotor 200 provided with a predetermined interval from the stator 100 , and the conductive wire 41 is wound neatly and in multiple layers around an insulating member 50 .

According to this embodiment, the wire 41 is neatly and multi-layeredly wound around the insulating member 50 by the plurality of protrusions 60 provided on the wire winding portion 52. This can improve the slot occupancy factor of the coil 40 in the slot 30, thereby realizing a highly efficient motor 1000.

It should be noted that, in the present embodiment, the protrusions 60 are respectively provided to extend from each corner 52e1 to 52e4 to the surface adjacent thereto, but the present invention is not particularly limited thereto. For example, as shown in FIG. 11 , the protrusions 60 may be provided only at each corner 52e1 to 52e4. In this case, the first layer of the wire 411 is also wound around the first end surface 52a at an inclined angle of crossing ε and is supported by the first surface 60a of the protrusion 60 and is neatly wound around the surface of the wire winding portion 52.

<Modification>

Fig. 12 to Fig. 15 are schematic diagrams of the first to fourth insulating members involved in this modification. It should be noted that, in each figure, Fig. (a) is a stereoscopic view seen from the axial upper end, and Fig. (b) is a stereoscopic view seen from the axial lower end. In addition, the same symbols are used in Fig. 12 to Fig. 15 to represent the same parts as those in the first embodiment, and detailed description is omitted.

In the configuration shown in the first embodiment, the protrusions 60 are provided at the corners 52e1 to 52e4. In contrast, in the configuration shown in this variation, protrusions 61 are also provided at other locations, such as the first side surface 52c and the second side surface 52d. This is the difference between this variation and the first embodiment.

For example, as shown in Fig. 12, a plurality of protrusions 61 may be provided on the first side surface 52c and the second side surface 52d, and the plurality of protrusions 61 may be spaced apart from each other in the radial direction and parallel to the inner surface 51b of the first flange portion 51. Specifically, a plurality of protrusions 61 extending straight from the corner 52e1 to the corner 52e2 may be provided on the first side surface 52c; and a plurality of protrusions 61 extending straight from the corner 52e3 to the corner 52e4 may be provided on the second side surface 52d.

As shown in FIG13, on the basis of the structure shown in FIG12, a plurality of protrusions 62 may be provided on the second end surface 52b, the plurality of protrusions 62 are spaced apart from each other in the radial direction and are parallel to the inner surface 51b of the first flange portion 51. Specifically, a plurality of protrusions 62 extending straight from the corner 52e2 to the corner 52e3 may be provided on the second end surface 52b. In the structure shown in FIG13, the protrusions 62 are provided to extend continuously from the corner 52e1 to the corner 52e3.

As shown in FIG. 14, on the basis of the structure shown in FIG. 13, a plurality of protrusions 63 may be further provided on the first end face 52a, so that the plurality of protrusions 63 are spaced apart from each other in the radial direction by a spacing Z. Specifically, a protrusion 63 extending straight from the corner 52e4 to the corner 52e1 may be provided on the first end face 52a. In the structure shown in FIG. 14, the plurality of protrusions 63 provided on the first end face 52a may be further inclined at a crossing angle ε with respect to a direction orthogonal to the radial direction, and the plurality of protrusions 63 are spaced apart from each other in the radial direction by a spacing Z.

By applying the insulating member 50 shown in FIGS. 12 to 14 to the stator 100, the same effects as those of the first embodiment can be obtained. In addition, by providing a plurality of protrusions 61 to 63 extending continuously from the surface of the wire winding portion 52 except for the corner portions 52e1 to 52e4, the winding position of the wire 41 can be reliably determined, so that the wire 41 can be stably wound neatly.

It should be noted that, as shown in FIG. 15 , the protrusions 64 provided on the first end surface 52 a , the second end surface 52 b , the first side surface 52 c , and the second side surface 52 d may be configured to be discontinuous in the extending direction instead of the configuration shown in FIG. 14 .

That is, the plurality of protrusions 64 provided on the first side surface 52c and the second side surface 52d are spaced apart from each other in the radial direction and the axial direction; the plurality of protrusions 64 provided on the second end surface 52b are spaced apart from each other in the radial direction and the circumferential direction. The plurality of protrusions 64 provided on the first end surface 52a are spaced apart from each other in the radial direction and the circumferential direction. It should be noted that the radial spacing of the protrusions 64 provided on each surface 52a to 52d is the spacing Z.

When the insulating member 50 shown in Fig. 15 is applied to the stator 100, the same effects as those of the first embodiment can be obtained. The shape of the protrusion 64 shown in Fig. 15 can also be applied to the configurations shown in Figs. 12 and 13, although not shown.

(Second Embodiment)

FIG16 is a schematic diagram of an insulating member according to the present embodiment, and FIG17 is a schematic diagram of a main part of a stator as seen from the axial upper end. It should be noted that FIG16 also shows an enlarged view of a portion surrounded by a dotted line; the same reference numerals are used in FIG16 to represent the same portions as those in the first embodiment, and detailed descriptions thereof are omitted. FIG17 shows only the first layer of conductors 411 among the conductors 41.

In the configuration shown in the first embodiment, the protrusion 60 provided at the corner 52e1 between the first end face 52a and the first side face 52c and the protrusion 60 provided at the corner 52e2 between the first side face 52c and the second end face 52b have their respective second surfaces 60b facing radially inward.

On the other hand, in the configuration of the present embodiment shown in FIG16 , the second surface 60b of the protrusion 60 provided at the corner 52e1 between the first end face 52a and the first side face 52c faces radially inward, whereas the second surface 60b of the protrusion 60 provided at the corner 52e2 between the first side face 52c and the second end face 52b faces radially outward. In other words, the second surfaces 60b of the former protrusion 60 and the latter protrusion 60 face opposite directions.

Depending on the design specifications of the motor 1000, it may be required to provide the intersection 4i on a surface different from the first end surface 52a of the wire winding portion 52. However, in the configuration shown in the first embodiment, it is difficult to provide the intersection 4i on a surface other than the first end surface 52a.

On the other hand, according to the present embodiment, the intersection 4i can be provided not only on the first end face 52a, but also on the second end face 52b. That is, the conductor 41 can also be wound from the jth layer (j is an integer, 1≤j≤n-1) to the j+1th layer on the second end face 52b, and the intersection 4i can also be provided on the second end face 52b. In this way, the degree of freedom in design of the stator 100 and thus the motor 1000 can be improved. It should be noted that in this case, for example, as shown in FIG. 17 , the first layer conductor 411 can be wound on the second end face 52b at a crossing angle ε relative to a direction orthogonal to the radial direction.

(Third Embodiment)

FIG. 18A is a cross-sectional schematic diagram of the main part of the stator involved in this embodiment; FIG. 18B is a cross-sectional schematic diagram of the main part of the stator for comparison. It should be noted that, for the sake of convenience, the protrusion 60 is omitted in FIG. 18A and FIG. 18B. In addition, the same reference numerals are used to represent the same parts as those in the first embodiment, and detailed description is omitted.

The structure of this embodiment shown in FIG18A is different from the structure of the first embodiment shown in FIG18B in that a step 52f of a predetermined height is provided at the portion where the kth turn (k is the number of turns of the first layer of the wire 411) of the radial inner end of the wire winding portion 52 is to be arranged. This is because the step 52f is connected to the surface of the wire winding portion 52, that is, the step 52f is provided on the first end face 52a, the second end face 52b, the first side face 52c, and the second side face 52d. In addition, the first layer of the wire 411 is not wound around the step 52f.

According to the present embodiment, it is possible to suppress the eddy current from flowing through the conductive wire 41 due to the magnetic flux passing through the inside of the coil 40, which eventually causes energy loss in the motor 1000. This will be described further.

As shown in FIG18B, when current flows through the conductive wire 41, a magnetic flux is generated that passes through the inside of the coil 40, that is, through the split yoke 21 and the inside of one tooth 10, and a part of the magnetic flux leaks to the conductive wire 41 at the radially inner end of one tooth 10. This leakage magnetic flux causes an eddy current to be generated in the conductive wire 41 on the side close to one tooth 10, for example, in the first layer conductive wire 411, and this eddy current is the cause of energy loss.

On the other hand, according to the present embodiment, as shown in FIG18A , a step 52f of a predetermined height is provided in the portion of the conductor 41 through which the leakage magnetic flux passes, which corresponds to the k-th turn located radially inward in the first-layer conductor 411, so that the first-layer conductor 411 is not wound in this portion. In this way, the leakage magnetic flux can be prevented from passing through the conductor 41, the generation of eddy current can be suppressed, and the energy loss of the motor 1000 can be suppressed.

It should be noted that the step 52f may also be provided across the k-1th turn and the kth turn of the first layer of the conductive wire 411. The step 52f may also be extended to the portion of the first turn of the second layer of the conductive wire 412. The height and radial length of the step 52f may be appropriately changed by taking into account the degree of reduction of the eddy current flowing through the conductive wire 41 and the degree of reduction of the slot space factor of the coil 40.

It should be noted that since the leakage flux has less influence on the side close to the split yoke 21 , in order to suppress the generation of eddy current, it is preferable to make the conductor 41 contact the inner surface 51 b of the first flange portion 51 when the conductor 41 contacts the conductor winding portion 52 .

(Fourth Embodiment)

FIG. 19A is a cross-sectional schematic diagram of the main part of the stator involved in this embodiment; FIG. 19B is a cross-sectional schematic diagram of the main part of the stator for comparison. It should be noted that, for the sake of convenience, the protrusion 60 is omitted in FIG. 19A and FIG. 19B. In addition, the same reference numerals are used to represent the same parts as those in the first embodiment, and detailed description is omitted.

In the configuration shown in FIG. 19B , the conductive wire 41 wound around one insulating member 50 and the conductive wire 41 wound around the other insulating member 50 of the insulating members 50 adjacent to each other in the circumferential direction are symmetrical in shape.

On the other hand, in the configuration of the present embodiment shown in FIG. 19A , the conductive wire 41 wound around one insulating member 50 and the conductive wire 41 wound around the other insulating member 50 of the insulating members 50 adjacent to each other in the circumferential direction are asymmetrical in shape.

By forming each conductive wire 41 into a winding shape as shown in Fig. 19A, the slot space factor of the coil 40 can be increased. This will be described further.

Generally, when the conductive wire 41 is wound around each of the plurality of insulating members 50 , the conductive wire 41 is wound symmetrically with respect to the surfaces of the coils 40 adjacent to each other in the circumferential direction in order to standardize the winding process and simplify the assembly process of the stator 100 .

In order to suppress mutual interference between coils 40 and to ensure insulation distance between coils 40 in a group of coils 40 wound in this way, the interval between circumferentially adjacent coils 40 and the interval between the plurality of teeth 10 on which they are mounted need to be set to be greater than a specified value.

However, depending on the size of the coil 40 and the number of turns of the conductive wire 41 , the interval may be too large, and the ineffective space in the slot 30 that is not occupied by the conductive wire 41 may become larger.

On the other hand, according to this embodiment, by making the conductive wires 41 respectively wound on the circumferentially adjacent insulating members 50 present an asymmetric winding shape, it is possible to reduce the above-mentioned non-effective space while ensuring the insulation distance between the circumferentially adjacent coils 40, thereby improving the wire slot occupancy factor of the coil 40.

It should be noted that, in the conductors 41 respectively wound around the insulating members 50 adjacent to each other in the circumferential direction, by making the winding shape of the lth turn (l is an integer, 1≤l≤k; k is the number of winding turns of the first layer of the conductor) of each conductor 41 asymmetrical, the degree of reduction of the ineffective space can be further improved, and the degree of freedom in design of the coil 40 can be improved. For example, as shown in FIG. 18A, the third and fourth turns of the conductor 41 located on the left side of the paper are made to have seven layers, respectively, while the third turn of the conductor 41 located on the right side of the paper is made to have six layers and the fourth turn is made to have five layers, thereby improving the degree of reduction of the ineffective space and also ensuring the insulation distance between the two coils 40. However, the winding shape of the conductor 41 is not particularly limited to this, and can be appropriately changed according to the size of the coil 40, the number of layers of the conductor 41, the number of winding turns, etc.

(Other embodiments)

In the first to fourth embodiments, with respect to the conductive wire 41 wound on the insulating member 50, as shown in FIG. 20, a heat dissipation material 70 is filled between the lth circle and the l+1th circle, between the i-1th layer and the i-th layer, that is, between the conductive wires 41 adjacent to each other in the circumferential direction and/or radial direction. The heat dissipation material 70 is used to dissipate the heat generated by the conductive wire 41 to the outside.

By configuring the stator 100 in this way, it is possible to suppress a temperature increase of the stator 100 and improve the efficiency of the motor 1000 .

In the first embodiment, the workpiece rotating winding method is used when winding the conductive wire 41 around the insulating member 50 , but the winding method of the coil 40 is not particularly limited.

For example, the stator support 2100 may be fixed and the nozzle 2200 may be moved instead of moving the stator support 2100, that is, the wire 41 may be wound around the insulating member 50 by a so-called wire rotary winding method. In this case, the yoke 20 may not be a structure in which the divided yokes 21 are connected in the circumferential direction, but the yoke 20 may be formed by punching electromagnetic steel sheets into a ring shape and stacking the punched electromagnetic steel sheets. After the yoke 20 is formed into a ring shape, the plurality of teeth 10 may be connected to the inner circumference of the yoke 20.

The insulator 50 may be a so-called split insulator that is attached from the upper and lower sides in the axial direction of one tooth 10 , or may be an integral structure that covers the entire outer peripheral surface of one tooth 10 .

In the stator 100 in the first to fourth embodiments, the coil 40 may be formed by a single-layered wire 41. In this case, the wire 41 is also neatly wound around each of the plurality of insulating members 50.

It should be noted that the cross-sectional shape of the wire 41 can be a quadrilateral as shown in Figures (a) and (b) of Figure 6, or a quadrilateral with four chamfered corners as shown in Figure (c) of Figure 6. The cross-sectional shape of the wire 41 is not limited to the shape shown in Figure 6, and for example, the side X can be longer than the side Y.

The cross-sectional shapes of one tooth 10 at the axial end and the axial center may be different. For example, the cross-sectional shape of one tooth 10 may be changed continuously or stepwise so that the width of the tooth 10 at both ends, at the upper end, or at the lower end in the axial end in the direction perpendicular to the radial direction is narrower than the width of the tooth 10 at the center in the direction perpendicular to the radial direction. The shape of the inner circumference of the wire winding portion 52 of the insulating member 50 may also be changed according to the change in the cross-sectional shape of one tooth 10.

Industrial Applicability

The stator of the present invention can improve the coil slot space factor, and therefore the stator of the present invention is particularly useful when applied to an electric motor requiring high efficiency.

Description of Reference Numerals

10+ teeth (one tooth)

20 Yoke

21 Split yoke

30 slots

40 Coil

41 Wire

4i Cross section

50 Insulation

51 First flange portion

51a Wire guide groove

51b Inner surface of the first flange portion 51

52 Wire winding part

52a First end surface

52b Second end face

52c First side

52d Second side

52e1～52e 4 corners

52f Stairs

53 Second flange portion

60～64 protrusion

60a Page 1

60b Side 2

70 heat dissipation material

100 Stator

200 rotor

210 Output shaft

220 Magnet

411 First layer wire

412 Second layer wire

413 Third layer wire

1000 Electric Motor

Claims (11)

1. A stator comprising an annular yoke, a plurality of teeth arranged at predetermined intervals in the circumferential direction of the yoke and extending from the inner circumference of the yoke in the radial direction of the yoke, a plurality of insulating members mounted on each of the plurality of teeth, and a plurality of coils composed of a conducting wire having a rectangular cross section and wound around each of the plurality of insulating members, characterized in that: The insulating member has a wire winding portion, a first flange portion and a second flange portion, The wire winding portion is in a cylindrical shape for winding the wire. The first flange portion is disposed at one end of the wire winding portion and has a wire guide groove for guiding the wire toward the wire winding portion. The second flange portion is disposed at the other end of the wire winding portion, The wire winding portion has a first end surface, a second end surface, a first side surface, a second side surface and a plurality of protrusions. The first end surface is connected to the bottom surface of the wire guide groove, and the second end surface is opposite to the first end surface in the axial direction of the stator. The first side surface and the second side surface are both arranged from the circumferential end edge of the first end surface to the circumferential end edge of the second end surface, and the first side surface and the second side surface are opposite to each other in the circumferential direction. The plurality of protrusions are provided at least at corners of the wire winding portion, and are used to wind the wire around the first end surface at a predetermined angle relative to a direction orthogonal to the radial direction. The plurality of protrusions are spaced apart from each other at predetermined intervals in the radial direction. The protrusion has a first surface opposite to the first flange portion and a second surface opposite to the second flange portion, At least one of the first surface and the second surface has a convex curved surface, The first layer of the wire wound on the wire winding portion is supported by the plurality of protrusions and wound at least on the first end surface at the prescribed angle and is wound on the surface of the wire winding portion at a prescribed inclination angle with respect to the radial direction. 2. The stator according to claim 1, characterized in that: The protrusion provided at the corner of the first end surface and the first side surface and the protrusion provided at the corner of the first side surface and the second end surface have the convex curved surfaces facing the same direction. 3. The stator according to claim 1, characterized in that: The protrusion provided at the corner of the first end surface and the first side surface and the protrusion provided at the corner of the first side surface and the second end surface have the convex curved surfaces facing in opposite directions. 4. The stator according to claim 1, characterized in that: The wire is wound in n layers in the wire winding portion, where n is an integer greater than 2. The i-th layer of wires is turned around from the i-1-th layer of wires on the first end surface and is wound around the i-1-th layer of wires at an angle different from the specified angle, i is an integer greater than 2 and i≤n, The i-th layer conductor is supported by the end surface of the i-1-th layer conductor and is wound around the i-1-th layer conductor at the predetermined inclination angle with respect to the radial direction. 5. The stator according to claim 4, characterized in that: The conductive wire is wound from the jth layer to the j+1th layer on the second end surface, where j is an integer, 1≤j≤n-1. 6. The stator according to claim 1, characterized in that: A step of a predetermined height is provided in the radial inner end of the wire winding portion where at least the kth winding portion of the first layer of wire is to be arranged, where k is the number of windings of the first layer of wire. At least the first layer of wires is not wound around the steps. 7. The stator according to claim 1, characterized in that: The winding shapes of the conductor wound around one insulating member and the conductor wound around another insulating member adjacent to the one insulating member in the circumferential direction are asymmetrical. 8. The stator according to claim 7, characterized in that: The winding shapes of the wire wound on the one insulating member and the wire wound on the other insulating member are asymmetric in their respective l-th turns, where l is an integer, 1≤l≤k, and k is the number of turns of the first layer of wire. 9. The stator according to claim 1, characterized in that: A heat dissipation material is filled between the conductive wires that are wound around an insulating member and are adjacent to each other in the circumferential direction or the radial direction. The heat dissipation material is used to dissipate heat generated in the conductive wires to the outside. 10. The stator according to any one of claims 1 to 9, characterized in that: The yoke is composed of a plurality of split yokes connected to each other in the circumferential direction. The plurality of teeth are respectively provided on each of the plurality of split yokes. 11. An electric motor, characterized in that: At least comprising the stator according to any one of claims 1 to 10 and a rotor provided with a predetermined interval between the stator and the rotor, The conductive wires are neatly wound around the insulating member in multiple layers.