JP2000175385A - Central-winding-system brushless dc motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a central-winding-system brushless DC motor where the position of a caulking part is arranged at a location that does not affect the magnetic path of a stator core as much as possible. SOLUTION: In a brushless DC motor, a stator gear tooth part 12 has a specific gear width X, and a gear tooth part tip part 13 is formed at an inner- diameter side gear tooth part up to an opening part excluding the gear tooth part while being extended to both the sides of the gear tooth part 12. A drive coil is directly wound around the gear tooth part 12 by utilizing the space of a slot 3 and hence the magnetic pole of a stator 1 is formed by the central direct-winding system. The position of the caulking part 4 that is clamped by laminating a stator core is arranged in a range on the extension line in the direction of outer diameter of a width wise dimension X of the gear tooth part 12 of the stator core 11 corresponding to a portion that less affects the passage of magnetic flux. A width Y of the caulking part 4 is set to the range of the width wise dimension X of the gear tooth part 12.

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 an arrangement of a caulking portion for laminating and fastening stator cores 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 concentrated winding type brushless DC motor is shown in FIG.
As shown in FIG. 2, the stator is constituted by a stator 1 and a rotor 2, and the stator has a shape as shown in FIG. 2A, and a stator core 11 is formed by laminating 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 tip portions 13 are provided on both sides thereof. 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, a stator having four poles and six slots 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. 1, and tooth tip portions 13 are formed on both sides of the tooth portion 12.

The rotor 2 has a shape as shown in FIG. 2B, and a rotor core 21 is formed by laminating silicon steel plates. A magnet 22 is embedded in the rotor core 21. As the magnet 22 of the rotor 2, an ordinary ferrite magnet may be used. However, to reduce the size of the motor, a magnet having a large BH product, that is, a neodymium magnet made of neodymium, iron, or boron, or a samarium-cobalt magnet is used. That is, a so-called rare earth magnet or the like 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 stacking and fastening the stator core of such a concentrated winding type brushless DC motor, it is usually performed by caulking, but since the stator core constitutes a magnetic circuit and is a path of magnetic flux, the position of the caulked portion is as small as possible. It is necessary to select a place that does not affect the magnetic path.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a concentrated winding type brushless in which the position of a caulking portion is arranged at a location where the magnetic path of a stator core of a motor is not affected as much as possible, and the stator cores are stacked and fastened. An object is to provide a DC motor.

[0009]

According to a first aspect of the present invention, there is provided a brushless DC motor of a concentrated winding type, wherein a stator core is formed by a caulking portion disposed in an outer radial extension of a stator tooth width X. It was configured to be stacked and fastened.

Thus, the stator of the brushless DC motor can be made small. In addition, the position of the swaging portion can be arranged on the outer peripheral side of the center of the stator teeth of the stator core of the concentrated winding type motor without affecting the magnetic circuit, and the reliability of the motor can be improved. .

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a concentrated winding type brushless DC motor according to the present invention which solves the above-mentioned problems. 3 and 4 are state diagrams of the magnetic flux distribution of the stator and the rotor. As shown in FIG. 3, when the magnets 22 of the rotor are positioned with respect to the tooth portions 12 of the stator core, the magnets are in the middle of the magnets and are in a weak state. Paying attention to the magnetic path at that time, the position indicated by 14 has little influence on the magnetic flux path.

When the magnet 22 of the rotor is positioned with respect to the teeth 12 of the stator core as shown in FIG. 4, the magnet is in a state where the magnetism is strongest because the magnet is completely opposed.
Paying attention to the magnetic path at that time, the position indicated by 14 has no influence irrespective of the magnetic flux path.

Therefore, the fourteenth position can be said to be an optimum position for arranging the position of the caulking portion while minimizing the influence on the magnetic path. Therefore, the present invention utilizes this phenomenon to position the caulking portion, stack the stator cores, and perform caulking.

FIG. 1 shows a plan view of the stator core 11,
The stator tooth portion 12 has a predetermined tooth width X, and a tooth tip portion 13 is formed on the inner diameter side tooth portion extending to both sides of the tooth portion 12 up to the opening except the tooth portion. A drive coil (not shown) is directly wound around the tooth portion 12 by utilizing the space of the slot 3, and the magnetic pole of the stator 1 is formed by a so-called concentrated series winding method.

The position of the caulking portion 4 for laminating and fastening the stator cores is located in the range of the width X of the tooth portion 12 of the stator core 11 extending in the outer diameter direction corresponding to the position 14 in FIGS. I do. The width Y of the caulking portion 4 is set within the range of the width dimension X of the tooth portion 12.

At the position of the caulking portion 4, the stator cores are laminated and fastened to form a stator core of a concentrated winding type brushless DC motor. The caulking portion 4 does not need to be provided on all of the teeth, and an arbitrary number of stator teeth 12
Can be provided.

[0017]

As described above, the present invention provides a brushless D
The stator of the C motor can be formed in a small size, and the tooth width X of the stator core of the concentrated winding type motor can be reduced.
By arranging the caulked portion in the range of extension in the outer diameter direction, the stator cores can be stacked and fastened without affecting the magnetic circuit, and the reliability of the motor can be improved.

[Brief description of the drawings]

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

FIG. 2 shows a concentrated winding type brushless DC motor stator and rotor.

FIG. 3 is a state diagram of a magnetic flux distribution of a stator and a rotor.

FIG. 4 is a state diagram of a magnetic flux distribution of a stator and a rotor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator 11 Stator core 12 Tooth part 13 Tooth tip part 14 Location with little magnetic influence 2 Rotor 21 Rotor core 22 Magnet 3 Slot 4 Caulking part

 ──────────────────────────────────────────────────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 AA01 AA09 AB06 AC06 AC08 5H019 AA04 AA07 CC03 CC08 DD01 EE14

Claims (1)

[Claims] In a concentrated winding type stator core, the stator cores are stacked and fastened by a caulking portion arranged in an outer radial extension of a stator tooth width dimension X. Brushless DC motor.