HK1104386B - Stator for motors - Google Patents

Description

Stator for an electric machine

Technical Field

The present invention relates to a stator for a motor.

Background

Japanese patent No. 2816698 (patent document 1) discloses a stator for a motor, which includes a stator core having a substantially annular yoke and a magnetic pole structure disposed inside the annular yoke, and a field coil portion provided on the magnetic pole structure. The magnetic pole structure integrally includes a plurality of poles having one end connected to the inside of the yoke, magnetic pole surface forming portions provided at the other ends of the plurality of poles, and a connecting portion connecting the two adjacent magnetic pole surface forming portions. The yoke and the magnetic pole forming body are respectively formed by laminating a plurality of magnetic steel plates. Further, a plurality of fitting recesses, which are opened in both directions in the lamination direction of the plurality of magnetic steel plates and the magnetic pole forming body and are fitted to one ends of the plurality of poles, are formed in the inner peripheral portion of the yoke.

Patent document 1: japanese patent application laid-open No. 2816698 and FIGS. 1 to 4

However, in the conventional stator for a motor, the inner circumferential surface of the annular yoke is curved in an arc shape. Therefore, the cross-sectional shape of the space in which the excitation coil portions formed on both sides of the pole are arranged is a sector. As a result, the shape of the exciting coil portion is limited by the shape of the space, and there is a limit to increasing the space factor of the coil.

Disclosure of Invention

The invention provides a stator for a motor, which can improve the space factor of an excitation coil part and make magnetic flux flow in a yoke easily.

Another object of the present invention is to provide a stator for a motor, which can increase the space factor of an exciting coil part without bending a flange part provided on a yoke side of a bobbin (bobbin) around which a coil conductor is wound.

It is still another object of the present invention to provide a stator for a motor that can prevent a reduction in mechanical strength of a flange portion of a bobbin on a yoke side.

A stator for a motor, which is an improved object of the present invention, includes: a stator core having an annular yoke and a magnetic pole forming body disposed inside the annular yoke; and N (N is an integer of 3 or more) excitation coil parts provided on the magnetic pole structure. The magnetic pole constituent body has N poles to which the exciting coil portions are fitted. The N pole columns are arranged inside the annular yoke with a space therebetween in the circumferential direction of the yoke, and each have one end connected to the yoke and the other end located radially inward of the one end. The other ends of the N pole columns are respectively provided with a plurality of magnetic pole surface forming portions having magnetic pole surfaces on the inner peripheral sides. The magnetic pole structure has a plurality of coupling portions for coupling two adjacent magnetic pole surface forming portions. The yoke and the magnetic pole structure are each formed by laminating a plurality of magnetic steel plates. N fitting recesses are formed in the inner periphery of the yoke, the recesses opening in both directions in the stacking direction of the plurality of magnetic steel plates and opening toward the magnetic pole forming body, and each fitting one end of the N poles. In the yoke used in the present invention, a pair of flat surface portions continuous with the inner surface of the fitting recess portion are formed on both sides in the circumferential direction of the N fitting recess portions. The sides of the pair of flat surface portions extending in the circumferential direction have the same length and are located in the same virtual plane.

In the conventional stator for a motor, since the yoke has an annular shape, the field coil portion accommodating space having a sector-shaped cross-sectional shape is formed on both sides of the pole. When the coil conductor is wound around the pole post to form the field coil portion, a large gap portion is formed between the inner peripheral portions of the bent yokes. In contrast, according to the present invention, when the configuration is such that the pair of flat surface portions are formed on both sides in the circumferential direction of the fitting recess portion in the inner circumferential portion of the yoke, the shape of the field coil portion housing space is a space in which the shape of the turn of the coil conductor of the field coil portion can be arranged in conformity with the pair of flat surface portions formed in the inner circumferential portion of the yoke. Therefore, a large gap portion is not formed between the excitation coil portion formed by winding the coil conductor around the pole and the pair of flat surface portions, as in the conventional technique. This can increase the ratio (space factor) of the arrangement space occupied by the coil conductor of the exciting coil portion. Further, the cross-sectional area of the yoke can be locally increased, and the magnetic flux can easily flow in the yoke.

Further, in the stator for a motor according to the present invention, the shape of the inner circumferential portion when the inner circumferential portion of the yoke is cut in the direction orthogonal to the lamination direction of the plurality of magnetic steel plates has a shape in which a shape of a regular N-sided polygon and N fitting recesses formed in the substantial centers of the sides of the shape of the regular N-sided polygon are combined. In addition, one end of the pole has a triangular shape. The exciting coil part includes a bobbin fitted to the pole. The bobbin has a space formed by a part of the bobbin and the pole fitted in the fitting recess. This prevents the mechanical strength of the yoke-side portion of the bobbin from being reduced.

In this case, when a distance between a vertex of a corner portion having one end of the pole in the triangular shape and a center point of the stator core is R, a width dimension in a direction orthogonal to a direction extending between the one end and the other end of the pole is T, a distance between a base of the triangular shape of the pole and the center point is x, and a distance between a point orthogonal to one side of an imaginary line orthogonal to one side of the N-polygon and passing through the center point and the center point is H, it is preferable that N, T and R have the following relationship.

T≤2R(1-cos(π/N))/tan(π/N)

Wherein H, x and R have a relationship of H < x < R. This allows the stator core to be formed without obstructing the flow of the effective magnetic flux contributing to torque generation, and thus allows an optimum magnetic circuit design.

The exciting coil portion may be constituted by a bobbin formed of an insulating material and fitted with the pole, and a coil conductor wound around the bobbin. In this case, the bobbin may include a cylindrical portion fitted to the pole and around which the coil conductor is wound, a first flange portion provided at one end of the cylindrical portion and contacting an inner peripheral surface of the yoke, and a second flange portion provided at the other end of the cylindrical portion and contacting the magnetic pole surface forming portion. The fitting recess and the first flange portion of the bobbin may have shapes such that a part of the first flange portion is fitted in the fitting recess. In this way, a part of the first flange portion is fitted in the fitting recess, whereby the mechanical strength of the first flange portion in contact with the inner peripheral surface of the yoke can be improved. Therefore, the thickness dimension of the first flange portion in contact with the pair of flat portions can be reduced, and the space factor of the exciting coil portion can be increased even when the bobbin is used.

Specifically, the bobbin is structured such that the first flange portion has a flat plate-like body portion conforming to the inner peripheral surface of the yoke, and a pair of rib portions rising from the body portion to the yoke side. The inner surface of the fitting recess is formed by a pair of inclined flat surface portions continuous with the pair of flat surface portions. The length of the side of the pair of inclined flat portions extending in the circumferential direction is preferably set such that a pair of spaces into which the pair of ribs of the bobbin are fitted are formed between the pair of inclined flat portions and one end of the pole fitted into the fitting recess. In this way, in a simple configuration in which the inner surface of the fitting recess is formed by the pair of inclined flat surface portions, a part of the first flange portion can be fitted in the fitting recess. The coil bobbin is positioned by fitting the rib and the fitting recess. In the first flange portion, the portion where the rib exists has a larger thickness dimension than the other portions. As a result, even if the thickness dimension of the flat plate-like main body portion of the first flange portion is reduced to be small and the volume of the space in which the coil conductor is disposed is increased as much as possible, the mechanical strength of the first flange portion can be prevented from being reduced.

Further, when the inner surfaces of the first flange portion and the second flange portion of the bobbin, which face each other, extend in parallel, the coil conductor can be wound around the cylindrical portion in a linearly aligned manner. Thus, the space factor of the exciting coil portion can be further increased.

(effect of the invention)

According to the present invention, since the pair of flat surface portions are formed on both sides in the circumferential direction of the fitting recess portion of the inner peripheral portion of the yoke, the shape of the field coil portion housing space is a space in which the turns of the coil conductor of the field coil portion can be arranged in conformity with the pair of flat surface portions formed on the inner peripheral portion of the yoke. This can increase the duty factor of the exciting coil portion. Further, the cross-sectional area of the yoke near one end of the pole can be increased, and the magnetic flux can easily flow in the yoke.

Further, in the present invention, the exciting coil portion includes the bobbin fitted with the pole, and a part of the bobbin is fitted in the space formed between the fitting recess and the pole fitted in the fitting recess, so that it is possible to prevent a reduction in mechanical strength of the yoke-side portion of the bobbin.

Drawings

Fig. 1 is a front view of a stator for a motor according to a first embodiment of the present invention.

Fig. 2 is a front view of a stator core used in the stator shown in fig. 1.

Fig. 3 is a diagram for explaining a mode of punching out the yoke magnetic steel plate and the magnetic steel plate for magnetic poles used in the stator shown in fig. 1 from a steel plate material.

Fig. 4 is a view for explaining a mode of assembling the stator shown in fig. 1.

Fig. 5 is a front view of a stator core used for a stator for a motor of a reference example.

Fig. 6 is a front view of a stator core used for a stator for a motor according to a second embodiment of the present invention.

Description of the symbols

Stator for 1 motor

3 stator core

5 exciting coil part

7 yoke

9 magnetic pole structure body

7a fitting recess

7b a pair of plane parts

7c a pair of inclined plane parts

13 pole

15 magnetic pole face forming part

17 connecting part

19 a pair of spaces

23 bobbin

23a cylindrical part

23b first flange part

23c second flange part

23d body part

23e a pair of ribs

25 coil conductor

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Fig. 1 is a front view of a stator for a motor according to a first embodiment of the present invention. As shown in the drawing, the stator 1 for a motor of the embodiment includes a stator core 3 and six field coil portions 5. As shown in fig. 2, the stator core 3 is composed of an annular yoke 7 and a magnetic pole constituent 9 disposed inside the annular yoke 7. Further, in fig. 2, a state where only one exciting coil part 5 is provided is described for reference. The yoke 7 is formed by laminating a plurality of yoke magnetic steel plates 11. The yoke is cut in a direction orthogonal to the stacking direction of the plurality of yoke magnetic steel plates 11 at the outer periphery of the yoke 7. The cut shape of the inner peripheral portion of the yoke 7 has a shape in which a regular N-sided polygon (regular hexagon in this example) shape and 6 fitting recesses 7a formed in the approximate centers of the sides of the regular hexagon shape are combined. Thus, the fitting recess 7a is formed in the inner circumferential portion of the yoke 7 so as to be open in both directions in the stacking direction of the plurality of magnetic steel plates and to be open to the magnetic pole structure 9. Further, a pair of flat surface portions 7b continuous with the inner surface of the fitting recess portion 7a are formed on both sides in the circumferential direction of the 6 fitting recess portions 7a in the inner circumferential portion of the yoke 7. The pair of flat surface portions 7b have sides extending in the circumferential direction of equal length and are located in the same imaginary plane. The inner surface of the fitting recess 7a is formed by a pair of inclined flat surface portions 7c continuous with the pair of flat surface portions 7 b.

The magnetic pole structure 9 includes N pole posts 13 (N is an integer of 3 or more, in this example, 6), a magnetic pole surface forming portion 15 provided at an end of the pole post 13, and a coupling portion 17 for coupling two adjacent magnetic pole surface forming portions. The pole post 13 is disposed inside the yoke 7 with a gap in the circumferential direction, and has one end coupled to the yoke 7 and the other end located radially inward of the one end. In this example, one end of the pole 13 has a triangular projection 13 a. Thus, the convex portion 13a has a pair of inclined surfaces 13b extending in the circumferential direction of the yoke 7. The projection 13a is fitted into the fitting recess 7a of the yoke 7 so that the pair of inclined surfaces 13b and the pair of inclined flat surfaces 7c of the yoke 7 are in contact with each other, whereby the pole 13 is coupled to the yoke 7. In this example, the yoke 7 has a circumferential length of the inclined surface 13b shorter than a circumferential length of the inclined flat surface portion 7 c. Thereby, a part of the pair of inclined flat portions 7c is exposed on the pole post 13 side, and a pair of spaces 19 having a triangular groove-like cross section are formed between a part of the pair of inclined flat portions 7c and the pole post 13. The magnetic pole surface forming portion 15 is provided at the other end of the pole post 13 and has a magnetic pole surface 15a facing the rotor on the inner circumferential side. A rotor, not shown, is disposed in a region surrounded by the magnetic pole surface 15 a.

Further, the magnetic pole structure 9 is configured by laminating a plurality of magnetic steel plates 21 for magnetic poles, as in the yoke 7. As shown in fig. 3, the one-piece yoke magnetic steel plate 11 constituting the yoke 7 and the one-piece yoke magnetic steel plate 21 constituting the magnetic pole constituent 9 are formed by punching a single piece of steel plate material M with a press machine. The yoke magnetic steel plate 11 has a flat surface portion forming portion 11a forming the flat surface portion 7b of the yoke 7 on the inner side, and an inclined flat surface portion forming portion 11b of the yoke 7 forming the inclined flat surface portion 7c of the yoke 7.

The magnetic steel plate 21 for magnetic pole has a pole-constituting portion 21a constituting the pole 13, a magnetic pole-surface portion 21b constituting the magnetic pole-surface forming portion 15, and a coupling-constituting portion 21c constituting the coupling portion 17. The pole constituent portion 21a has an inclined surface constituent portion 21d constituting the inclined surface 13 b. Then, a part of the two adjacent flat surface portion constituting portions 11a of the yoke magnetic steel plate 11 and two adjacent inclined surface portion constituting portions 21d of the magnetic steel plate 21 are cut by a press machine. In the subsequent step, since the pole post 13 and the yoke 7 are coupled so that the inclined surface forming portions 21d and the inclined plane forming portions 11b are in contact with each other, the angle θ 1 between the adjacent two inclined surface forming portions 21d and the angle θ 2 between the adjacent two inclined plane forming portions 11b can be appropriately set in accordance with the coupled state. For example, the angle θ 1 may be slightly smaller than the angle θ 2 to facilitate the connection between the pole 13 and the yoke 7, and the angle θ 1 may be substantially the same as the angle θ 2 or the angle θ 1 may be slightly larger than the angle θ 2 to securely connect the pole 13 and the yoke 7.

As shown in fig. 2, the field coil unit 5 is made of an insulating material, and includes a bobbin 23 fitted to the pole post 13 and a coil conductor 25 wound around the bobbin 23. The bobbin 23 integrally includes a cylindrical portion 23a fitted to the pole post 13, a first flange portion 23b provided at one end portion of the cylindrical portion 23a and contacting the inner peripheral surface of the yoke 7, and a second flange portion 23c provided at the other end portion of the cylindrical portion 23a and contacting the magnetic pole surface forming portion 15. Inner surfaces of the first flange portion 23b and the second flange portion 23c facing each other extend in parallel. The coil conductors 25 are wound around the cylindrical portion 23a so as to be aligned (aligned) in a straight line. The first flange portion 23b includes a flat plate-like body portion 23d rising from the cylindrical portion 23a and a pair of ribs 23 e. The pair of ribs 23e are located on the opposite side of the cylindrical portion 23a and rise from the body portion 23d to the yoke 7 side. The pair of ribs 23e have a triangular cross section and extend in the lamination direction of the yoke magnetic steel plates 11. In a state where the field coil unit 5 is mounted on the stator core 3, the main body portion 23d contacts the pair of flat surface portions 7b, and the pair of rib portions 23e are fitted in the pair of spaces 19 between the yoke 7 and the magnetic pole structure 9. That is, the fitting recess 7a and the first flange portion 23b of the yoke 7 are shaped such that a part (the pair of ribs 23e) of the first flange portion 23b fits in the fitting recess 7 a. In other words, the length of the sides of the pair of inclined flat portions 7c extending in the circumferential direction of the yoke 7 is set so that a pair of spaces 19 into which the pair of ribs 23e of the first flange portion 23b of the bobbin 23 are fitted are formed between the pair of inclined flat portions 7c of the fitting recess 7a and the one end (the convex portion 13a) of the pole 13 fitted into the fitting recess 7 a.

In the stator core 3 of this example, when the distance between the vertex of the corner at one end of the pole 13 and the center point C of the stator core 3 is R, the width dimension in the direction orthogonal to the direction extending between the one end and the other end of the pole 13 is T, the distance between the base of the triangular projection 13a of the pole 13 and the center point C is x, and the distance between the point orthogonal to one side of the regular hexagon that is orthogonal to the inner peripheral portion of the yoke 7 and the virtual line passing through the center point C and the center point is H, N, T and R have a relationship of T ≦ 2R (1-cos (pi/N))/tan (pi/N). In addition, H, x and R have a relationship of H < x < R.

In this example, the stator 1 is assembled as follows. First, the field coil section 5 is produced by winding the coil conductor 25 around the bobbin 23. Next, as shown in fig. 4, the field coil part 5 is fitted into the pole 13 of the magnetic pole constituent 9. Thereby, the second flange portion 23c of the bobbin 23 contacts the magnetic pole surface forming portion 15 of the magnetic pole constituent 9. Next, the convex portion 13a of the pole post 13 is fitted into the fitting concave portion 7a of the yoke 7, and the magnetic pole constituent 9 provided with the field coil part 5 is mounted on the yoke 7. As a result, as shown in fig. 2, the main body portion 23d of the bobbin 23 comes into contact with the pair of flat surface portions 7b, and the pair of ribs 23e are fitted into the pair of spaces 19 between the yoke 7 and the magnetic pole forming body 9.

According to the stator 1 of this embodiment, since the pair of flat surface portions 7b are formed on both sides in the circumferential direction of the fitting recess portion 7a in the inner circumferential portion of the yoke 7, the shape of the field coil portion housing space does not form a large gap portion between the field coil portion 5 and the pair of flat surface portions 7b formed by winding the coil conductor 25 around the pole post 13 as in the conventional art, in order to form a space in which the turns of the coil conductor 25 of the field coil portion 5 can be arranged in conformity with the pair of flat surface portions 7b formed in the inner circumferential portion of the yoke 7. This can increase the space factor of the exciting coil part 5. Further, the cross-sectional area of the yoke 7 can be locally increased, and the magnetic flux can easily flow in the yoke 7. In the first flange portion 23b, the portion where the rib portion 23e exists has a larger thickness dimension than other portions. As a result, even if the thickness dimension of the flat plate-shaped main body portion 23d of the first flange portion 23b is reduced to increase the volume of the space in which the coil conductor 25 is disposed as much as possible, the mechanical strength of the first flange portion 23b can be prevented from being reduced.

Fig. 5 is a front view of a stator core used in the stator of the reference example. The stator of the present reference example has the same configuration as the stator of the first embodiment, except for the shape of the inner surface of the fitting recess 107 a. In this example, the inner surface of the fitting recess 107a is constituted by a pair of vertical surfaces 107d continuous with the pair of flat surfaces 107b and extending at right angles to the pair of flat surfaces 107b, and a pair of inclined flat surfaces 107c continuous with the pair of vertical surfaces 107 d. Even in the stator of this example, the space factor of the field coil portion can be increased, and a decrease in the magnetic flux density flowing through the yoke 107 can be suppressed. However, since a part of the first flange portion of the bobbin is not fitted in the fitting recess portion 107a of the yoke 107, an effect of being able to reduce the thickness dimension of the first flange portion as in the first embodiment cannot be obtained.

Fig. 6 is a front view of a stator core used in a stator according to a second embodiment of the present invention. The stator of this example is a 9-slot stator including 9 poles 213. Since the stator of this example has basically the same configuration as the stator of the first embodiment except for the number of poles, 200 is added to the reference numeral given to the stator of the first embodiment, and the description thereof is omitted.

Claims (5)

1. A stator for an electric machine, comprising: a stator core having an annular yoke and a magnetic pole forming body disposed inside the annular yoke; and N exciting coil parts provided on the magnetic pole structure, wherein N is an integer of 3 or more,

the magnetic pole constituent body comprises: n pole columns which are arranged inside the annular yoke with a space therebetween in the circumferential direction of the yoke, each of which has one end connected to the yoke and the other end located radially inside the one end, and to which the excitation coil part is attached; a plurality of magnetic pole surface forming portions which are respectively provided at the other end and have magnetic pole surfaces on the inner peripheral side; and a connecting portion for connecting the two adjacent magnetic pole surface forming portions,

the yoke and the magnetic pole constituting body are each formed by laminating a plurality of magnetic steel plates,

n fitting recesses that are open in both directions of the lamination direction of the plurality of magnetic steel plates, open toward the magnetic pole forming body, and fit to the one ends of the N pole posts, respectively, are formed in the inner peripheral portion of the yoke,

the stator for an electrical machine is characterized in that,

a pair of flat surface portions continuous to an inner surface of the fitting recess portion are formed on both sides of the fitting recess portions in the circumferential direction of the N number of the fitting recess portions,

the length dimensions of the sides of the pair of flat surface portions extending in the circumferential direction are equal and are located in the same plane,

the shape of the inner peripheral portion when the inner peripheral portion of the yoke is cut in a direction orthogonal to the lamination direction of the plurality of magnetic steel plates has a shape in which a shape of a regular N-sided polygon and N fitting concave portions formed at substantially centers of sides of the shape of the regular N-sided polygon are combined,

the one end of the pole has a triangular shape,

the exciting coil part includes a bobbin fitted to the pole,

the bobbin is configured such that a part of the bobbin is fitted into a space formed between the fitting recess and the pole fitted in the fitting recess.

2. A stator for an electrical machine according to claim 1,

when a distance between a vertex of a corner of the one end of the pole having the triangular shape and a center point of the stator core is R, a width dimension in a direction orthogonal to a direction extending between the one end and the other end of the pole is T, a distance between a base of the triangular shape of the pole and the center point is x, and a distance between a point orthogonal to one side of the N-sided polygon and a line passing through the center point and orthogonal to the one side and the center point is H, the N, the T, and the R have a relationship of T < 2R (1-cos (pi/N))/tan (pi/N),

said H, said x and said R having a relationship H < x < R.

3. A stator for an electrical machine according to claim 2,

the exciting coil part is composed of the bobbin formed of an insulating material and fitted into the pole, and a coil conductor wound around the bobbin,

the bobbin includes: a cylindrical portion fitted to the pole and around which the coil conductor is wound; a first flange portion provided at one end of the cylindrical portion and contacting an inner circumferential surface of the yoke; and a second flange portion provided at the other end portion of the cylindrical portion and contacting the magnetic pole face forming portion,

the fitting recess and the first flange portion of the bobbin are shaped such that a part of the first flange portion fits in the fitting recess.

4. A stator for an electrical machine according to claim 3,

the first flange portion has a flat plate-like body portion conforming to an inner peripheral surface of the yoke and a pair of rib portions rising from the body portion to the yoke side,

the inner surface of the fitting recess portion is formed of a pair of inclined flat surface portions continuous with the pair of flat surface portions,

the length of the side of the pair of inclined flat portions extending in the circumferential direction is set so that a pair of spaces into which the pair of ribs of the bobbin are fitted are formed between the pair of inclined flat portions and the one end of the pole fitted into the fitting recess.

5. A stator for an electrical machine according to claim 3 or 4,

inner surfaces of the first flange portion and the second flange portion of the bobbin that face each other extend in parallel,

the coil conductors are wound around the cylindrical portion in an orderly arrangement.