JPH07222420A - Outer-rotor brushless dc motor - Google Patents

Abstract

PURPOSE:To provide an outer-rotor brushless DC motor which can suppress vibrations and noises without a molding operation and which can be miniaturized and mass-produced. CONSTITUTION:A prescribed space is constituted by coupling a first housing 2 and a second housing 3 in which mounting recessed parts used to mount bearing metals 6, 6a are formed respectively by the drawing operation of steel plates. A magnetic support 8 which is formed so as to be along the inside of the second housing 3 by bending a magnetic steel plate and which holds a magnetic substance 9 so as to surround the outer circumference of a stator 7 is fixed to a shaft 13 which is inserted into, passed through, and supported by, both bearing metals 6, 6a for the first and second bearings 2, 3 so as to be freely rotatable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer rotor type brushless DC motor used for home electric appliances.

[0002]

2. Description of the Related Art Today, many motors are used in home appliances. For example, taking a small air conditioner as an example, a motor having an output of several W to several tens W is used as a motor for an indoor unit fan and an outdoor unit fan, and recently, a brushless DC motor is also used to improve the operation efficiency. It is supposed to be used. And such a brushless D
As the C motor, for example, as shown in Japanese Utility Model Publication No. 63-16297, an outer configured such that a rotor mounted with a magnetic body rotates around a stator formed by winding coils around a plurality of teeth. Rotor type and actual public Sho 63-
There is an inner rotor type in which a rotor is arranged inside a stator as shown in Japanese Patent No. 34449.

By the way, in a small air conditioner, it is a big problem to downsize the fan motor in response to the downsizing of the unit. Here, the relationship between the motor torque (T) and the stator core is represented by T = L × D * 2. Note that D is the inner diameter of the air gap, and L is the product thickness of the plurality of teeth.

Therefore, in order to increase the torque and output of the motor, the inner diameter (D) of the air gap may be increased. When comparing the inner rotor type and the outer rotor type which generate the same torque and output, Since the outer rotor type in which the inner diameter (D) of the air gap is large can reduce the product thickness of a plurality of teeth, it can be thinned. In addition, the outer rotor type is capable of high-speed winding work of the winding as will be described later, and the number of assembling steps can be reduced.

On the other hand, in such an outer rotor type brushless DC motor, for example, Japanese Laid-Open Patent Publication No. 4-2361.
As disclosed in Japanese Patent No. 55, the stator is molded with a thermosetting resin which is a thermosetting synthetic resin in order to suppress vibration and noise.

[0006]

However, in such a conventional outer rotor type brushless DC motor, it takes a lot of time to remove the mold once it is molded, and therefore, it occurs in the production process, for example. Motors that have become unusable due to defective products or product life have been treated by means such as burying the stator as it is without collecting it, and there was a problem in terms of environmental problems and resource reuse. In addition, since the molding process takes a long molding time, there is a problem that when mass-producing, the number of mechanical equipments increases and it is not possible to cope with rapid mass production.

Therefore, the present invention has been made to solve such a problem, and provides an outer rotor type brushless DC motor which can suppress vibration and noise without molding and can be mass-produced in a small size. The purpose is to do.

[0008]

An outer rotor type brushless DC motor according to the present invention is constructed such that a rotor having a magnetic body mounted rotates around the outer circumference of a stator formed by winding coils around a plurality of teeth. In the outer rotor type brushless DC motor, the first housing has a mounting recess formed by double drawing of a steel plate, and a mounting recess formed by double drawing of a steel plate. A second housing which is coupled with the second housing to form a predetermined space, and is formed into a cylindrical shape by drawing a steel plate, and one end of the second housing is attached to the outside of a mounting recess formed by double drawing of the first housing. On the other hand, a stator support cylinder to which the stator is attached on the outer periphery of the other end, and a magnetic steel plate that is formed along the inner side of the second housing and is located in the predetermined space. A magnetic body support body that holds the magnetic body so as to surround the outer periphery of the stator, a bearing metal on the side of the first housing and a second metal housing that are mounted in mounting recesses of the first housing and the second housing, respectively. Side bearing metal, and a shaft rotatably inserted through and supported by the bearing metal and the magnetic body support is fixedly attached.

The outer rotor type DC brushless motor of the present invention is an outer rotor type DC brushless motor in which a rotor having a magnetic material is rotated around the outer periphery of a stator formed by winding coils around a plurality of teeth. The brushless DC motor has a first housing having a mounting recess formed by double drawing of a steel plate, and a mounting recess formed by double drawing of a steel plate, and being combined with the first housing. A second housing forming a predetermined space and a cylindrical shape formed by drawing a steel plate, one end of which is attached to the outside of a mounting recess formed by double drawing of the first housing, while the other end A stator support cylinder to which the stator is attached on the outer periphery of the portion, and a magnetic steel plate that is formed along the inner side of the second housing and is located in the predetermined space. A magnetic body support for holding the magnetic body so as to surround the outer periphery of the data, and a bearing metal on the side of the first housing, which is provided in a bearing housing that is mounted in the mounting recesses of the first housing and the second housing, respectively. A bearing metal on the second housing side and a shaft rotatably inserted into and supported by the bearing metal and the magnetic support are fixedly attached.

[0010]

In the outer rotor type brushless DC motor configured as described above, the bearing metal can be supported by the first housing and the second housing formed by double drawing of a steel plate.

Further, after the bearing metal is housed in the bearing housing, it can be supported by the first housing or the second housing.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an outer rotor type brushless DC motor according to an embodiment of the present invention. In the figure, 1 is an outer rotor type brushless DC motor main body (hereinafter referred to as a motor main body), and 2 and 3 are a first housing and a second housing which form a casing of the motor main body 1.

Here, the first housing 2 is formed by drawing a steel plate, and as shown in FIG. 2, a mounting recess 4 is formed integrally in the center by double drawing to open inward. It is a thing. The second housing 3 is formed by drawing a steel plate into a cylindrical shape with a bottom, and as shown in FIG. 3, a mounting recess 5 that opens inward with a double drawing is integrally formed on the bottom surface to form a first housing. It is connected to the housing 2.

Incidentally, as shown in FIG. 1, these mounting recesses 4, 5 are fitted with a bearing metal (bearing portion) 6 and a bearing metal (bearing portion) 6a for inserting and supporting a shaft 13 which will be described later. It has become. Further, in FIG. 2, 21 is a screw hole, 22 is a rib for attaching the second housing, 31 is a screw hole, and 32 is an insertion hole through which the shaft is inserted.

In the figure, reference numeral 7 is a stator, and 8 is a magnetic body support which is a rotor on which a permanent magnet 9 which is a magnetic body is mounted. Here, the stator 7 is formed by winding a coil L after performing stator insulation on a stator core 10 formed by stacking a plurality of electromagnetic steel plates punched into a shape having a plurality of teeth as shown in FIG. Is.

In this stator core 10, as shown in the figure, since the plurality of groove portions 10a around which the coil L is wound are open to the outside, the stator core of the inner rotor is opened to the inside. High-speed winding work is possible compared with the winding work of. Also, this stator 7 is
The layers are skewed and stacked, whereby the cogging torque is reduced, and vibration and noise during motor operation can be reduced.

By the way, the stator 7 is press-fitted and attached to the outer circumference of a stator support cylinder 12 formed by drawing a part of the steel plate of the first housing 2 into a cylindrical shape. A stepped portion 12a for positioning the stator 7, which is press-fitted and fixed to the stator support cylinder 12, is provided.
Is formed by drawing.

In this way, the stepped portion 12a for positioning is formed in the stator support cylinder 12 in a narrowed manner, and the stator 7 is pressed against the stepped portion 12a to make the mounting position of the stator 7 constant. I am able to Further, by fixing the stator 7 at a fixed position in this way, it is possible to prevent the stator 7 from shaking, so that it is possible to prevent vibration and noise from being generated, and to support the magnetic body as defined by the Electrical Appliance and Material Control Law. A spatial distance from the body 7 can also be secured.

The inner diameter of the stepped portion 12a is set so that the bearing metal 6 can be incorporated therein.
It is formed so as to be larger than the outer diameter of No. 5.

On the other hand, the magnetic support 8 is formed by bending a magnetic steel plate into a shape along the second housing 3, and
An outer annular yoke 8a, which is located in a predetermined space formed by connecting the first housing 2 and the second housing 3 together, and which mounts and fixes the magnetic body 9 on the inner periphery as shown in FIGS. 5 and 6. From this annular yoke 8a, the shaft 1 described later
3, and a space between the yoke side wall 8b and the bearing metal 6, 6a (see FIG. 1)
Cylindrical shaft mounting portion 8c formed so as to extend to
It consists of and.

Then, by attaching and fixing the magnetic body 9 to the inner circumference of the annular yoke 8a in this manner, the magnetic body support 8 is formed.
The annular yoke 8a can receive the centrifugal force applied to the magnetic body 9 during rotation of the magnetic body 9 and thus prevent the magnetic body 9 from cracking and scattering.

Further, the magnetic support 8 is attached to the second housing 3
The width of the motor main body 1 in the width direction can be reduced by forming the motor main body 1 in a shape along the shaft mounting portion 8c.
By extending the space between the two bearings 6, 6a to utilize the space between the bearings 6, 6a.
The thickness of the motor in the height direction can be reduced, which allows the motor body 1 to be downsized.

Around the bearing metal 6, there are provided a self-aligning spring 15a, an oil cap 15b, a wick 15c soaked with o-oil, and a thrust bearing 15d. Similarly, around the bearing metal 6a, the bearing housing 16, the self-aligning spring 16a, the oil cap 16b,
A wick 16c soaked with oil is provided. The bearing housing 16 is press-fitted into the first housing 3 similarly to the bearing housing 15.

The shaft 13 is rotatably inserted into the bearing metals 6 and 6a and supported by both ends, and is also press-fitted into the shaft mounting portion 8c to mount and fix the magnetic support 8.

FIG. 7 is a sectional view of an outer rotor type brushless DC motor showing another embodiment of the present invention. In this figure, the outer rotor type brushless D shown in FIG.
The difference from the C motor is that the first housing 2 and the bearing housing 15 are integrally formed by drawing, and the second housing 3 and the bearing housing 16 are integrally formed by drawing. This is in that the stator support cylinder 12 is formed as a separate component by drawing, and the stator support 12 and the like are press-fitted into the folded portion of the first housing 2.

[0027]

As described above, according to the present invention, the first housing, the second housing, the stator support cylinder, the magnetic body support, and the like are formed by drawing, and these components are combined and fixed to form a motor. By doing so, manufacturing is simple and mass production is possible. Further, the stator and the stator are press-fitted and fixed to the stator support cylinder, and the stator support cylinder is attached and fixed to the first housing, whereby vibration and noise can be suppressed without molding. As a result, it is possible to mass-produce a small outer rotor type brushless DC motor that has good workability due to manufacturing mainly by press working, is inexpensive, and has high quality.

[0028]

[Brief description of drawings]

FIG. 1 is a side sectional view of an outer rotor type brushless DC motor according to an embodiment of the present invention.

2 is a plan view of a first housing of the motor shown in FIG.

3 is a plan view of a second housing of the motor shown in FIG.

4 is a plan view of a stator core of the motor shown in FIG.

5 is a side sectional view of a magnetic support of the motor shown in FIG.

FIG. 6 is a plan view of the stator support cylinder shown in FIG.

FIG. 7 is a side sectional view of an outer rotor type brushless DC motor according to another embodiment of the invention.

[Explanation of symbols]

 1 Motor Main Body 2, 2A, 2B 1st Housing 3, 3A 2nd Housing 6, 6a Bearing Metal 7 Stator 12, 16, 17 Stator Support Tube 13 Shaft

Claims (2)

[Claims] 1. An outer rotor type brushless DC motor in which a rotor equipped with a magnetic material rotates around an outer circumference of a stator formed by winding a coil around a plurality of teeth, and a steel sheet is double-drawn. A first housing having a mounting recess formed by, and a second housing having a mounting recess formed by double drawing of a steel plate and forming a predetermined space by coupling with the first housing, A stator support, which is formed into a cylindrical shape by drawing a steel plate, one end of which is attached to the outside of a mounting recess formed by double drawing of the first housing, and the other end of which is attached to the stator. A cylinder and a magnetic body formed by machining a magnetic steel plate so as to extend along the inner side of the second housing, located in the predetermined space, and holding the magnetic body so as to surround the outer circumference of the stator. A support, a bearing metal on the side of the first housing and a bearing metal on the side of the second housing, which are respectively mounted in mounting recesses of the first housing and the second housing, and are rotatably inserted and supported by both bearing metals. An outer rotor type brushless DC motor, comprising: a shaft to which the magnetic support is fixedly attached. 2. In an outer rotor type brushless DC motor in which a rotor having a magnetic material mounted is rotated around the outer circumference of a stator formed by winding a coil around a plurality of teeth, a double drawing of a steel plate is performed. A first housing having a mounting recess formed by, and a second housing having a mounting recess formed by double drawing of a steel plate and forming a predetermined space by coupling with the first housing, A stator support, which is formed into a cylindrical shape by drawing a steel plate, one end of which is attached to the outside of a mounting recess formed by double drawing of the first housing, and the other end of which is attached to the stator. A cylinder and a magnetic body formed by machining a magnetic steel plate so as to extend along the inner side of the second housing, located in the predetermined space, and holding the magnetic body so as to surround the outer circumference of the stator. A support, a bearing metal on the side of the first housing and a bearing metal on the side of the second housing, which are provided in bearing housings mounted in mounting recesses of the first housing and the second housing, respectively; An outer rotor type brushless DC motor comprising: a shaft rotatably inserted and supported, and the shaft on which the magnetic support is fixedly attached.