JPH07163117A - Outer rotor type brushless DC motor - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an outer rotor type brushless DC motor that can suppress vibration and noise without molding and can be mass-produced. [Structure] The first housing 2 and the second housing 3 in which the mounting recesses of the bearings 6 and 6a are respectively formed by double drawing of a steel plate are combined to form a predetermined space. Further, the stator 7 is attached to the outer periphery of the other end of the stator support cylinder 12 attached to the first housing 2 by attaching one end to the outside of the attachment recess of the first housing 2.
Further, a magnetic body support 8 which is formed along the inner side of the second housing 3 and holds the magnetic body 9 so as to surround the outer periphery of the stator 7 is rotatably inserted and supported by both bearings 6 and 6a. The shaft 13 is attached and fixed. Furthermore, by interposing the vibration-proof rubber 14 between the shaft mounting portion 8c of the magnetic body support 8 and the shaft 13, the vibration of the magnetic body support 8 is prevented from being transmitted to the shaft 13.

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, a rotor mounted with a permanent magnet, which is a magnetic material, rotates around a stator formed by winding coils around a plurality of teeth. There are an outer rotor type configured and an inner rotor type having a structure in which a rotor is arranged inside a stator as disclosed in Japanese Utility Model Publication No. 63-34449.

By the way, in a small air conditioner, downsizing of a motor for a fan has become a major issue in response to downsizing of a 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]

SUMMARY OF THE INVENTION The present invention is an outer rotor type brushless DC motor in which a rotor having a magnetic material is rotated around the outer circumference of a stator formed by winding coils around a plurality of teeth. 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, the first housing
A second housing that is combined with the housing to form a predetermined space, and is formed into a cylindrical shape by drawing a steel plate, and one end thereof 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 circumference of the other end, and a stator steel cylinder formed by machining a magnetic steel plate along the inner side of the second housing and located in the predetermined space. A magnetic body support for holding the magnetic body so as to surround the
On the other hand, the first housing-side bearing and the second housing-side bearing, which are respectively mounted in the mounting recesses of the first housing and the second housing, and the shaft rotatably inserted and supported by the both bearings, A cylindrical shaft mounting portion extending in the space between the both bearings is formed on the magnetic support, and a vibration-proof rubber is interposed between the shaft mounting portion and the shaft.

Also, in the present invention, the anti-vibration rubber is press-fitted between a metal outer sleeve inserted and fixed in the shaft mounting portion and a metal inner sleeve in which the shaft is press-fitted and fixed. Is installed.

[0010]

According to the first aspect of the invention, the first housing has the mounting recess for mounting the bearing formed by double drawing of the steel plate, and the second housing has the mounting recess for mounting the bearing formed by double drawing of the steel plate. Can be combined with a predetermined space to form a predetermined space. In addition, a stator support tube that is formed into a cylindrical shape by drawing a steel plate and that is attached to the first housing in a state of being positioned in a predetermined space by attaching one end to the outside of the attachment recess of the first housing A stator can be attached to the outer circumference of the end.

Further, a magnetic body support body is formed by bending the magnetic steel plate so as to extend along the inside of the second housing, and holds a magnetic body so as to surround the outer circumference of the stator.
It can be attached and fixed to a shaft that is rotatably inserted and supported by both bearings of the first and second housings. Further, a cylindrical shaft mounting portion extending in the space between the bearings is formed on the magnetic body support, and a vibration-proof rubber is interposed between the shaft mounting portion and the shaft to support the magnetic body. It is possible to prevent body vibration from being transmitted to the shaft.

According to the second aspect of the present invention, the anti-vibration rubber is press-fitted between the metal outer sleeve into which the shaft is fitted and fixed and the metal inner sleeve into which the shaft is press-fitted. By mounting it, it is possible to reduce the trouble of fixing the magnetic support to the shaft.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment 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 and FIG. 3 which is a sectional view taken along line AA of FIG. The mounting recess 4 that opens to the side is integrally formed. In addition, the second housing 3 is formed by drawing a steel plate into a cylindrical shape with a bottom, and a mounting recess 5 that is open to the inside by a double drawing is integrally formed on the bottom surface and is connected to the first housing 2. Is.

The mounting recesses 4 and 5 are fitted with a first bearing (bearing portion) 6 and a second bearing (bearing portion) 6a for inserting and supporting a shaft, which will be described later, as shown in FIG. It is like this. Further, in FIGS. 2 and 3, reference numeral 21 is a rib for attaching the second housing.

In the figure, reference numeral 7 is a stator, and 8 is a magnetic body support which is a rotor having a permanent magnet 9 mounted thereon. Here, in the stator 7, the coil L is formed after the stator core 10 in which a plurality of electromagnetic steel plates punched to have a plurality of teeth as shown in FIG.
It is formed by winding.

In this stator core 10, as shown in the same figure, the plurality of open grooves 10a around which the coil L is wound are open to the outside, so that the stator of the inner rotor is opened to the inside of the open grooves. 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. On the other hand, the winding start, the winding end, the terminal of the lead wire, and the like of the coil L wound around the stator 7 are not shown in the figure, but are not shown in the figure. It is designed to be connected to.

By the way, the stator 7 is formed by drawing a steel plate into a cylindrical shape as shown in FIGS.
The one end portion 12A is press-fitted and fixed to the outer circumference of the other end portion 12B of the stator support cylinder 12 that is fitted and fixed to the outside of the double throttle portion 23 (see FIG. 2) of the first housing 2. . A stepped portion 12a for positioning the stator 7, which is press-fitted and fixed, is formed at the other end 12B of the stator support cylinder 12 by drawing.

In this way, the stepped portion 12a for positioning is formed on 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 stepped portion 12a has an inner diameter that allows the first bearing 6 to be assembled after the stator support cylinder 12 is fitted and fixed to the first housing 2. It is formed to be larger than. Further, when the stator support cylinder 12 is fitted and fixed to the outside of the throttle portion 23 of the first housing 2, since the throttle portion 23 is double formed, it hardly bends toward the mounting recess 4 side. 1 The bearing 6 can be installed without damaging it.

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 combining the first housing 2 and the second housing 3 with the permanent magnet 9 mounted and fixed to the inner circumference, as shown in FIG.
And a yoke side wall 8b bent from the annular yoke 8a toward a shaft 13 described later, and the yoke side wall 8
and a cylindrical shaft mounting portion 8c formed so as to extend from b to the space between the first and second bearings 6 and 6a.

By thus fixing and fixing the permanent magnet 9 on the inner circumference of the annular yoke 8a, the centrifugal force applied to the permanent magnet 9 when the magnetic support 8 rotates is applied to the annular yoke 8a.
Therefore, the permanent magnet 9 can be prevented from cracking and scattering.

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.

By the way, the shaft 13 is rotatably inserted into the first and second bearings 6 and 6a to be supported by the both-end type, and the vibration-proof rubber 14 interposed between the shaft 13 and the shaft mounting portion 8c. The magnetic support 8 is attached and fixed via the. The anti-vibration rubber 14 is attached to the shaft 13
Is press-fitted and fixed between the metal inner sleeve 15 and the shaft mounting portion 8c.
In this way, the shaft mounting portion 8 in which the anti-vibration rubber 14 is incorporated
The magnetic support 8 is attached to the shaft 13 by press-fitting and fixing the shaft 13 in the inner sleeve 15 of c.

A knurl (not shown) is formed on the shaft 13. The knurl allows the inner sleeve 15 to be fixed to the shaft 13 without rotating, so that the magnetic support 8 is fixed to the shaft. It is designed so that it does not come off from 13.

On the other hand, in the figure, 16 is a bearing receiver, and 17 is a preload spring for pressing the first bearing 6 mounted in the mounting recess 4 of the first housing 2 against the bearing receiver 16. In addition, in this embodiment, a drainer 13a is press-fitted into the shaft 13 so that water droplets do not enter the inside through the shaft 13 and the second
The mounting recess 5 of the housing 3 is covered with a waterproof cap 18 having a drain hole 18a formed in the lower portion.

Next, the assembling operation of the outer rotor type brushless DC motor thus constructed will be described.

In order to assemble the motor body 1, first, the stator 7 is press-fitted onto the outer periphery of the stator support cylinder 12 until it hits the stepped portion 12a, and then the stator support cylinder 12 is fixed to the double throttle portion of the first housing 2. It is fitted and fixed to the outside of 23 to fix the stator 7 at a fixed position.

Next, after inserting the preload spring 15 into the mounting recess 4 of the first housing 2, the first bearing 6 is passed through the stator support tube 12 and fitted into the mounting recess 4 of the first housing 2. . Further, thereafter, one end of the shaft 13, which is integrally press-fitted into the shaft mounting portion 8c in which the anti-vibration rubber 14 is installed and is integrated with the magnetic support 8, is inserted into the first bearing 6.

Next, after inserting the second bearing 6a from the other end of the shaft 13, the second bearing 6a is moved along the shaft 13 and fitted into the mounting recess 5 of the second housing 3. As a result, the shaft 13 is rotatably inserted and supported by the two bearings 6 and 6a. Finally, the second housing 3 is attached to the first housing 2 with a screw, and the second bearing 6a fitted in the mounting recess 5 of the second housing 3 is fixed.
Is pressed into the shaft 13 and the mounting recess 5 of the second housing 3 is covered with the waterproof cap 18.

The motor body 1 thus assembled can be miniaturized because the first housing 2 and the second housing 3 are formed by drawing a steel plate. Further, the stator 7 is press-fitted and fixed to the stator support cylinder 12, and the stator support cylinder 12 is attached to the second housing 2 of the first housing 2.
By fitting the outer side of the heavy throttle, the stator 7 can be fixed without molding.

Further, the magnetic body support 8 is formed by bending a magnetic steel plate so as to extend along the second housing 3, so that the motor body 1 can be made thinner. Furthermore, by interposing the anti-vibration rubber 14 between the magnetic body support 8 and the shaft 13, it is possible to prevent the vibration of the magnetic body support 8 from being transmitted to the shaft 13.

By the way, in the above description, the anti-vibration rubber 14 has been described as being press-fitted and fixed between the shaft mounting portion 8c and the inner sleeve 15, but the present invention is not limited to this, and the drawings are not limited thereto. Inner sleeve 1 as shown in FIG.
5 and an outer sleeve 19 made of metal, which is inserted and fixed inside the shaft attachment portion 8c, is press-fitted and fixed to the sleeve body 2
You may make it form 0.

Then, after the sleeve body 20 is once inserted and fixed inside the shaft mounting portion 8c, the shaft 13 is press-fitted and fixed to the inner sleeve 15 of the sleeve body 20, and then the shaft 13 is fixed as shown in FIG. It may be attached. As a result, it is possible to simplify the trouble of fixing the magnetic body support 8 to the shaft 13 with the antivibration rubber 14 interposed.

[0036]

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 is press-fitted and fixed to the stator support cylinder, the stator support cylinder is attached and fixed to the first housing, and the anti-vibration rubber is interposed between the stator support cylinder and the shaft so that vibration does not occur without molding. And noise can be suppressed. This allows
A small outer rotor type brushless DC that has high workability due to manufacturing mainly by press working and is inexpensive and of high quality.
Motors can be mass-produced.

[0037]

[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 invention of claim 1 of the present invention.

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

FIG. 3 is a sectional view of the first housing AA.

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

FIG. 5 is a side sectional view of a stator support cylinder of the motor.

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

FIG. 7 is a side sectional view of a sleeve body mounted on the outer rotor type brushless DC motor according to the second aspect of the present invention.

FIG. 8 is a side sectional view of an outer rotor type brushless DC motor equipped with the sleeve body.

[Explanation of symbols]

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

Claims (2)

[Claims] 1. An outer rotor type brushless DC motor in which a rotor having a magnetic material mounted is configured to rotate around an outer periphery of a stator formed by winding coils around a plurality of teeth. Having a mounting recess formed by
A housing, a second housing having a mounting recess formed by double drawing of a steel plate, and combining with the first housing to form a predetermined space, and a cylindrical shape formed by drawing the steel plate, One end is the first
A stator support cylinder that is attached to the outside of the attachment recess formed by double drawing of the housing, and the stator is attached to the outer periphery of the other end, and a shape that follows the inside of the second housing by machining a magnetic steel plate. A magnetic body support member that is formed in the predetermined space and holds the magnetic body so as to surround the outer circumference of the stator; and the magnetic body support body is attached to mounting recesses of the first housing and the second housing, respectively. A bearing on the first housing side, a bearing on the second housing side, and a shaft rotatably inserted into and supported by both bearings are provided, while the magnetic body support extends in a space between both bearings. An outer rotor type brushless characterized in that a cylindrical shaft mounting portion is formed, and a vibration-proof rubber is interposed between the shaft mounting portion and the shaft. DC motor. 2. The anti-vibration rubber is press-fitted and mounted between a metal outer sleeve inserted and fixed inside the shaft mounting portion and a metal inner sleeve into which the shaft is press-fitted and fixed. The outer rotor type brushless DC motor according to claim 1, wherein: