JP2000175381A - Concentrated winding brushless dc motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concentrated winding brushless DC motor for preventing a bundle of coils at a coil end from sticking out inside a stator through stress of the coil when the coil is turned on a stator core. SOLUTION: In a brushless DC motor, a tooth part 12 of a stator core 1 has a shape, in which a bottom width (A) of a slot bottom part is made smaller than an inner width (B) of an inner diameter side part, so a lower-layer coil turned in a shape like a fan toward an inner diameter side of a stator has a tendency of moving force to a slot bottom. Then, useless stress is not applied to the coil when a driving coil is turned on a tooth part of the stator core, and a bundle of coil at a coil end is prevented from sticking out in a stator inner diameter side, and high quality can be kept.

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 the shape of teeth of a stator core of a motor 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 brushless DC motor of the concentrated winding type is shown in FIG.
As shown in FIG. 3, the stator 1 and the rotor 2 are provided. The stator has a shape as shown in FIG. 3A, and a stator core (silicon steel plate) is formed by laminating stator plates (silicon steel plates).

[0005] The stator core 11 is provided with a tooth portion 12,
The tooth portion 12 has a predetermined tooth width, and the tooth portion tip 1
3 are provided. A drive coil (not shown) is directly wound around the tooth portion 12 using the space of the slot portion, and a magnetic pole of the stator 1 is formed by a so-called concentrated series winding method.
In this example, the stator has four poles and six slots, and the plan view of the stator core 11 is as shown in FIG.

The rotor 2 has a shape as shown in FIG. 3B, 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] The rotor 2 is inserted into the center of the stator 1 formed as described above to form a concentrated winding type brushless DC motor, so that it is formed smaller than a stator of a distributed winding type brushless DC motor. be able to.

When the drive coil 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 poles of the stator 1 by the concentrated series winding method, the concentrated winding motor uses the winding mechanism of the winding. As the tension is strong,
In the conventional stator tooth shape shown in FIG. 5, since the width A of the slot bottom portion and the width B of the stator inner diameter side portion were the same, the coil bundle on the coil end was easily protruded to the stator inner diameter side. In order to prevent this, forcibly performing shaping requires a man-hour for the shaping and is one of the factors that cause quality deterioration.

[0009]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a concentrated winding method in which a coil bundle on a coil end does not protrude to the inner diameter side of a stator due to stress caused by a coil when a driving coil is wound around a tooth portion of a stator core. It is an object of the present invention to provide a brushless DC motor.

[0010]

According to a first aspect of the present invention, there is provided a concentrated winding type brushless DC motor. In a concentrated winding type motor stator, a tooth shape of a stator core is set such that a portion of a stator inner diameter side of a slot bottom portion with respect to a slot bottom portion. It has a wide width.

Thus, when the drive coil is wound around the teeth of the stator core, the coil bundle on the coil end is prevented from protruding toward the inner diameter side of the stator, and the quality can be maintained. In addition, compulsory shaping for preventing protrusion is not required, and the number of working steps can be reduced.

[0012]

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. FIG. 1 is a schematic plan view of the stator shown in FIG. 2A focusing only on one tooth portion of a stator core 11 of the stator.

In the present invention, the stator core teeth 12 of the stator core 11 are formed such that the width B of the stator inner diameter side portion is wider than the width A of the slot bottom portion.
The lower-layer coil formed in a fan shape toward the inner diameter side of the stator and wound thereon generates a moving force toward the bottom of the slot. Tooth portion 1 of other stator core of stator core 11
2 is formed similarly.

Thus, when the drive coil is wound around the teeth of the stator core, no extra stress is applied to the coil, the coil bundle on the coil end is prevented from protruding toward the inner diameter side of the stator, and the quality is maintained. be able to. In addition, compulsory shaping for preventing protrusion is not required, and the number of working steps can be reduced.

[0015]

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 the drive coil is wound around the teeth of the stator core,
It is possible to prevent the coil bundle on the coil end from protruding to the inner diameter side of the stator, and to maintain the quality. In addition, compulsory shaping for preventing protrusion is not required, and the number of working steps can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a tooth shape of a stator core according to the present invention.

FIG. 2 is a plan view of a tooth shape of a conventional theta core.

FIG. 3 shows a stator and a rotor of a concentrated winding type brushless DC motor.

FIG. 4 is a plan view of a 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

Continued on the front page (72) Inventor Masaaki Takezawa 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Toshito Yanashima 2-5- Keihanhondori, Moriguchi-shi, Osaka No. 5 Inside Sanyo Electric Co., Ltd. (72) Inventor Keishiro Igarashi 2-5-5 Sanyo Electric Co., Ltd. (72) Inventor Shigemi Koiso Keihan Motodori, Moriguchi City, Osaka Pref. 2-5-5 Sanyo Electric Co., Ltd. F term (reference) 5H002 AA07 AB00 5H019 AA10 CC03 EE01 EE14

Claims (1)

[Claims] 1. A brushless DC motor of a concentrated winding type wherein a stator core of a concentrated winding type motor has a tooth shape of a stator core wider on a side of a stator inner diameter than a slot bottom.