JP2000175380A - Concentrated winding brushless dc motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concentrated winding brushless DC motor with small variation in torque and small noises caused by the variation of the torque. SOLUTION: A brushless DC motor includes a stator 1 having a stator core 11 with a skew at a skew angle ϕ that is satisfied with an angle of (7.5±5) deg. to a stator axis. A rotor core 21 of a rotor 2 has a skew at a skew angle ϕthat is satisfied with an angle of (7.5±5) deg. to the stator axis. Both the stator 1 and the rotor 2 may have the skew, and in this case, these skew angles should be satisfied with a relative angle of (7.5±5) deg. to each other.

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 suitable for use as a drive motor of a hermetic compressor with reduced vibration and noise of the motor.

[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 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 4 poles and 6 slots is used. is there.

The rotor 2 has a shape as shown in FIG. 2B, 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.

[0006] 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 the stator is formed smaller than a distributed winding type brushless DC motor stator. be able to.
However, even with the brushless DC motor of the concentrated winding type having such a configuration, the fluctuation of the torque and the generation of the accompanying noise cannot be completely eliminated as characteristics of the motor. The accompanying noise had to be tolerated.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a brushless DC of a concentrated winding type in which fluctuations in torque and the accompanying noise are reduced by analyzing the structure and characteristics of a motor.
An object is to provide a motor.

[0008]

According to a first aspect of the present invention, there is provided a concentrated winding type brushless DC motor, wherein a skew is applied to a stator core of a stator of a concentrated winding type motor, and a skew angle is set with respect to an axis of the stator. 7.5 ± 5
It was configured to satisfy the angle of degree.

According to a second aspect of the present invention, there is provided a brushless DC motor of the concentrated winding type, wherein a skew is applied to a rotor core of the rotor of the concentrated winding type motor, and the skew angle is 7.5 ± 5 degrees with respect to the axis of the rotor. Satisfying the above angle.

A concentrated winding type brushless DC motor according to a third aspect of the present invention is a concentrated winding type motor,
A skew is applied to both the stator core and the rotor core, and the skew angle of both satisfies the relative angle of 7.5 ± 5 degrees.

[0011] Thus, by skewing the stator or the rotor individually or to both the stator and the rotor, it is possible to reduce the fluctuation of torque and the accompanying noise.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, in a brushless DC motor of a concentrated winding type by analyzing the structure and characteristics of a motor, the stator or the rotor can be individually provided in the same manner as when skew is applied to the rotor of an AC motor. Alternatively, attention has been paid to the fact that skew is applied to both the stator and the rotor to thereby reduce fluctuations in torque and the accompanying noise.

As a result of the analysis, the relationship between the skew angle and the torque variation is as shown in FIG. 3. By setting the angle φ to 7.5 ± 5 degrees, the torque variation can be reduced to the minimum value. There was found. It was also confirmed that the skew can be reduced individually by applying skew to the stator or the rotor or to both the stator and the rotor.

An embodiment of a brushless DC motor of the concentrated winding type according to the present invention will be described with reference to the drawings. In FIG. 1, the same components as those in FIG. 2 are denoted by the same reference numerals. FIG. 1A shows an embodiment of the present invention applied to a stator, in which a skew is applied to a stator core 11 and a skew angle φ is set to satisfy an angle of 7.5 ± 5 degrees with respect to the axis of the stator. It was done.

FIG. 1B shows another embodiment of the present invention which is applied to a rotor. In recent years, a magnet which is deformable as a magnet to be inserted into the rotor and can cope with a hole has been realized. 21 is skewed, and the skew angle φ is set so as to satisfy an angle of 7.5 ± 5 degrees with respect to the axis of the stator.

As another embodiment of the present invention, although not shown, skew may be applied to both the stator and the rotor. In this case, the skew angle φ between the stator core 11 and the rotor core 21 is set so that the relative angle satisfies the angle of 7.5 ± 5 degrees.

[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 by analyzing the structure and characteristics of the motor, the skew can be applied to the stator or the rotor individually or to both the stator and the rotor to cause the torque fluctuation and the accompanying noise. And a brushless DC motor of a concentrated winding type in which the occurrence of the occurrence is reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a skewed stator and rotor of the present invention.

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

FIG. 3 is a characteristic diagram of torque fluctuation and skew angle.

[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 Continuing on the front page (72) Inventor Masaaki Takezawa 2-5-1-5, Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Toshito Yanajima 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 AA04 AB00 AC00 5H019 AA02 AA06 CC03 CC09 DD01 EE01 EE14 5H622 AA02 CA02 CA07 CA10 CA13 CB03 PP03 PP10

Claims (3)

[Claims] In a concentrated winding type motor stator, a skew is applied to a stator core, and a skew angle satisfies an angle of 7.5 ± 5 degrees with respect to an axis of the stator. Brushless DC motor. 2. A concentrated winding type motor rotor comprising:
A brushless DC motor of a concentrated winding type, wherein a skew is applied to a rotor core and a skew angle satisfies an angle of 7.5 ± 5 degrees with respect to a shaft of the rotor. 3. A concentrated winding motor, wherein skew is applied to both a stator core and a rotor core, and the skew angle of both satisfies an angle of 7.5 ± 5 degrees. Type brushless DC motor.