JP2000166134A - Concentrated winding system brushless dc motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concentrated winding system brushless DC motor, which prevents the insides of coil ends from bulging out from the inside diameter of a stator, when a drive coil is wound on the magnetic poles of the stator. SOLUTION: (A) is the Figure of the part of a stator core 11 magnified paying attention to one tooth part 12. The tooth part 12 has a specified tooth width, and teeth tip parts 13 are formed on the left and right of inside-diameter side tooth parts up to an opening which excludes tooth parts. They are so formed that a distance T of a line A connecting both point A and point A' from a tangent (line) B of the inside diameter of teeth parts on the basis of tangent (line) B satisfies T>=0 (on the side of the outside diameter of the stator), when a left tip and a right tip which are the intersections of the teeth tip parts 13 of the stator with line D and line C represented as point A and point A' respectively. By forming the tooth tip parts 13 of the stator in this way, it becomes possible to prevent the insides of the coil ends from bulging out from the inside diameter of the stator, even if a drive coil is wound up to the peripheries of the openings of the tooth parts of the stator core, when magnetic poles of the stator are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concentrated winding type brushless DC motor which is characterized by a structure of a motor stator and is suitable for use as a drive motor of a hermetic compressor.

[0002]

2. Description of the Related Art Recently, with the spread of air conditioners such as air conditioners, it has been required to reduce the size in terms of shape, but to increase energy efficiency in order to save power. It is desired that the driving motor used in the vehicle be reduced in size and increased in efficiency.

Conventionally, a brushless DC motor of a distributed winding type is generally used as a drive motor for a hermetic compressor. However, the applicant of the present invention has concentrated winding to simplify the manufacturing process, reduce the size and increase the efficiency. A brushless DC motor of the type was proposed.

A concentrated winding type brushless DC motor is shown in FIG.
As shown in FIG. 4, the stator is constituted by a stator 1 and a rotor 2, and the stator has a shape as shown in FIG. 4A, and a stator core 11 is formed by stacking stator plates (silicon steel plates). The stator core 11 is provided with a tooth portion 12, and the tooth portion 12 has a predetermined tooth width, and tooth end portions 13 are provided on both sides thereof along the surface of the rotor. A drive coil (not shown) is directly wound around the tooth portion 12 using the space of the slot portion, and the magnetic poles of the stator 1 are formed by a so-called concentrated series winding method. In this example, a stator having four poles and six slots is used. Is shown.

[0005] This makes it possible to reduce the size of the stator of the brushless DC motor of the distributed winding type. The shape of the stator core 1 is as shown in the plan view of FIG. 5, and tooth tip portions 13 are formed on both sides of the tooth portion 12 so that the distance from the rotor is evenly spaced along the rotor surface. Is done.

The rotor 2 has a shape as shown in FIG. 4B, and a rotor core 21 is formed by laminating silicon steel plates. A permanent magnet 22 is embedded in the rotor core 21. As the permanent magnet 22 of the rotor 2, an ordinary ferrite-based magnet may be used.
A so-called rare earth magnet such as a magnet having a large product, that is, a neodymium magnet made of neodymium, iron, or boron, or a samarium-cobalt-based magnet can be used.

[0007] A rotor 2 is inserted into the center of the stator 1 thus formed to constitute a concentrated winding type brushless DC motor. When a driving coil (not shown) is directly wound around the tooth portion 12 of the stator core 11 by utilizing the space of the slot portion to form the magnetic pole of the stator 1 by the concentrated series winding method, the tooth tip portion 13 of the stator core 11 is formed. As shown in FIG. 3, the distance T from the line A connecting the point A and the point A ′ of the tooth tip 13 and the distance T from the tangent B of the inner diameter of the tooth 12 is
When T ≦ 0 (closer to the stator inner diameter), the pitch of one slot is as large as 60 degrees, and when the drive coil is wound around the opening, the inside of the coil end may protrude beyond the stator inner diameter.

Heretofore, in order to prevent the stator inner diameter of the coil end from protruding, a molded product such as resin formed integrally with the slot insulating paper so as to form a wall on the inner diameter side of the stator is used. The structure to prevent the inside diameter of the coil from protruding from the resin molded product is such that if the coil is occupied at a high rate and a thick wire is used for the coil, strong stress will be applied to the resin molded product during winding and the product will fall or crack, etc. There was a problem. For this reason, when the thickness of the resin molded product is increased in order to secure the strength, in the case of a hermetic compressor using a refrigerant, the generation of oligomers precipitated from the resin has become a problem.

[0009]

Accordingly, the present invention prevents the inside of the coil end from protruding beyond the inner diameter of the stator even when the drive coil is wound near the opening of the teeth of the stator core when forming the magnetic pole of the stator. It is an object of the present invention to provide a concentrated winding type brushless DC motor.

[0010]

According to a first aspect of the present invention, there is provided a concentrated winding type brushless DC motor, comprising: a left end and a right end of a tooth end of a stator core of a stator core of the concentrated winding type motor; The distance T from the tangent B of the inner diameter of the tooth portion of the line A connecting the points A and A 'is configured to be T ≧ 0 (closer to the outer diameter of the stator).

According to a second aspect of the present invention, there is provided a brushless DC motor of a concentrated winding type, wherein a cut portion is formed at a tip end of a tooth of a stator core of the concentrated winding type motor at an inner diameter side toothed portion up to an opening excluding a toothed portion. The distance T from the tangent line B to the inner diameter of the tooth portion of the line A connecting the point A and the point A 'of the left and right ends of the tooth portion tip of the stator core is T ≧ 0 (closer to the stator outer diameter). Configured.

According to a third aspect of the present invention, there is provided a brushless DC motor of the concentrated winding type, wherein the tooth of the stator core of the concentrated winding type motor is cut on one side of the inner diameter side teeth up to the opening excluding the teeth. The distance T from the tangent B of the inner diameter of the tooth of the line A connecting the point A and the point A 'of the tip of the tooth of the stator core is T ≧ 0 (closer to the outer diameter of the stator). It was constituted so that it might become.

According to a fourth aspect of the present invention, there is provided a brushless DC motor of the concentrated winding type, wherein the teeth of the stator core of the concentrated winding type motor are cut on both sides of the inner diameter side teeth up to the opening excluding the teeth. The distance T from the tangent B of the inner diameter of the tooth of the line A connecting the point A and the point A 'of the tip of the tooth of the stator core is T ≧ 0 (closer to the outer diameter of the stator). It was constituted so that it might become.

[0014] Thus, the stator of the brushless DC motor can be formed in a small size, and when forming the magnetic poles of the stator, it is possible to use a resin molded product without using a resin molded product.
A brushless DC motor of a concentrated winding type in which the inside of the coil end is prevented from protruding beyond the inner diameter of the stator even when the drive coil is wound around the opening of the teeth of the stator core.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a concentrated winding type brushless DC motor according to the present invention will be described with reference to the drawings. According to the present invention, as shown in FIGS. 3 and 5, the shape of the stator core 1 is such that the tooth tip portions 13 on both sides of the tooth portion 12 are uniformly spaced from the rotor along the surface of the rotor. However, for the purpose of reducing torque fluctuation and preventing vibration of motor rotation, a concentrated winding type brushless DC motor proposed by the present applicant will be described.

FIG. 1B is an enlarged view of a part of the stator core 11. In the tip shape of the teeth 12 of the stator core 11, the inner diameter of the teeth tip 13 up to the opening excluding the teeth is shown. The cut portions a and b are provided. The overall front view of the stator core 11 is, as shown in FIG.
It has 6 slots.

The tooth tip 13 formed to extend on both sides of the tooth 12 is removed by cutting a part b thereof. The cut portion is sufficient only at the tooth tip portion 13 in the direction in which the rotation of the rotor 2 is directed, for example, one side of a is sufficient. However, the tooth portions are inserted so that the rotor 2 can be inserted from either direction of the stator 1 when assembling the motor. The other b of the tip 13 is also cut. Thus, the tooth tip portions 13 on both sides
The effect on the torque characteristics of the motor is negligible even if is cut.

FIG. 1A is an enlarged view of a part of the stator core 11 and focuses on one tooth portion 12.
Has a predetermined tooth width, and tooth tip portions 13 are formed on the right and left sides of the inner diameter side tooth portion up to the opening except the tooth portion. Line (line) D and line (line) of stator tooth tip 13
The left and right ends that are the intersections of C are point A and point A ', respectively.
The distance T from the tangent (line) B is determined based on the tangent (line) B of the inner diameter of the tooth portion of the line (line) A connecting the two points.
Are formed so that T ≧ 0 (closer to the stator outer diameter).

By forming the teeth 13 of the stator in this way, when forming the magnetic poles of the stator, even if the drive coil is wound near the opening of the teeth of the stator core, the inside of the coil end is the inner diameter of the stator. Can be prevented from protruding.

[0020]

As described above, the present invention provides a brushless D
The stator of the C motor can be formed in a small size, and when forming the magnetic poles of the stator, the drive coil is wound around the opening of the teeth of the stator core without using a resin molded product. A brushless DC motor of a concentrated winding type in which the brushless DC motor is prevented from protruding beyond the stator inner diameter can be realized.

[Brief description of the drawings]

FIG. 1 is a partially enlarged view of a stator core of the present invention.

FIG. 2 is a plan view of a stator core according to the present invention.

FIG. 3 is a partially enlarged view of a conventional stator core.

FIG. 4 shows a stator and a rotor of a concentrated winding type brushless DC motor.

FIG. 5 is a plan view of a conventional stator core.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator 11 Stator core 12 Tooth 13 Tooth tip 2 Rotor 21 Rotor core 22 Magnet

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaaki Takezawa 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Toshito Yanashima 2 Keihanhondori, Moriguchi-shi, Osaka 5-5-5 Sanyo Electric Co., Ltd. (72) Inventor Keishiro Igarashi 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Pref. Sanyo Electric Co., Ltd. (72) Inventor Shigemi Koiso, Moriguchi-shi, Osaka 2-5-5 Keihanhondori Sanyo Electric Co., Ltd. F-term (reference) 5H002 AA07 AE07 5H019 AA07 CC03 CC08 DD01 EE01 EE14 5H621 GA01 GA12 GB10 HH01

Claims (4)

[Claims] 1. A distance T from a tangent line B of an inner diameter of a tooth portion of a line A connecting a point A and a point A 'on the right and left ends of the tooth portion of the stator core of the stator core of the concentrated winding type motor. Is a brushless DC motor of a concentrated winding type, wherein T ≧ 0 (closer to the outer diameter of the stator). 2. A concentrated winding type motor in which a cut portion is provided at an inner diameter side tooth portion to an opening excluding a tooth portion at a tooth end portion of a stator core of a stator core, wherein left and right ends A of the tooth end portion of the stator core are provided. A brushless DC motor of a concentrated winding type, wherein a distance T from a tangent B of an inner diameter of a tooth portion of a line A connecting a point A and a point A is T ≧ 0 (closer to an outer diameter of a stator). 3. The concentrated winding type brushless DC motor according to claim 2, wherein the cut portion is provided on one side of the inner diameter side tooth portion up to the opening except the tooth portion. 4. A brushless DC motor of a concentrated winding type according to claim 2, wherein said cut portions are provided on both sides of an inner diameter side tooth portion up to an opening except a tooth portion.