JP2896059B2 - Outer rotor type brushless DC motor - Google Patents

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 electric motors are used in home electric appliances. For example, taking a small air conditioner as an example, a motor having an output of about several W to several tens of W is used as a motor for the indoor unit fan and the outdoor unit fan, and a brushless DC motor has recently been used to improve operation efficiency. Is being used. And such a brushless D
As the C motor, for example, as shown in Japanese Utility Model Publication No. 63-16297, a rotor having a permanent magnet as 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 disposed inside a stator as disclosed in Japanese Utility Model Publication No. 63-34449.

[0003] In the case of small air conditioners, it has become a major problem to reduce the size of a fan motor in accordance with the size 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 inside diameter of the air gap, and L is the thickness of a plurality of teeth.

Accordingly, in order to increase the torque and the output of the motor, the inner diameter (D) of the air gap may be increased, and a comparison is made between an inner rotor type and an outer rotor type which generate the same torque and output. In addition, the outer rotor type in which the inner diameter (D) of the air gap is large can reduce the thickness of the plurality of teeth, so that the thickness can be reduced. Further, the outer rotor type is capable of high-speed winding work of windings as 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 Unexamined Patent Publication No.
In order to suppress vibration and noise as disclosed in Japanese Patent Publication No. 55-55, a stator is molded with a thermosetting resin which is a thermosetting synthetic resin.

[0006]

However, in such a conventional outer rotor type brushless DC motor, once molded, it takes a lot of trouble to remove the mold. Defective products and motors that have become unusable due to product life have been treated by means such as burying them in mountains without collecting the stator, and have had problems in terms of environmental issues and resource reuse. In addition, since the molding operation requires a long molding time, there is a problem that, when mass-producing, the number of machinery and equipment increases, and rapid mass production cannot be coped with.

Accordingly, 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. It is intended to do so.

[0008]

SUMMARY OF THE INVENTION The present invention provides an outer rotor type brushless DC motor in which a rotor having a magnetic material mounted thereon rotates around a stator having a plurality of teeth wound with coils. A first housing having a mounting recess formed by double drawing of a steel plate, and a first housing having a mounting recess formed by double drawing of a steel plate;
A second housing coupled to the housing to form a predetermined space; and a cylindrical shape formed by drawing a steel plate, one end of which is mounted outside a mounting recess formed by the double drawing of the first housing. A stator support cylinder to which the stator is mounted on the outer periphery of the other end; and a magnetic steel plate formed along the inside of the second housing by processing a magnetic steel plate and located in the predetermined space. A magnetic body support that holds the magnetic body so as to surround the
A first housing-side bearing and a second housing-side bearing which are respectively mounted in mounting recesses of the first housing and the second housing, and a shaft rotatably inserted and supported by the two bearings; The magnetic body support has a cylindrical shaft mounting portion extending into a space between the bearings, and a vibration isolating rubber is interposed between the shaft mounting portion and the shaft.

Further, according to the present invention, the vibration isolation rubber is press-fitted between a metal outer sleeve inserted and fixed inside the shaft mounting portion and a metal inner sleeve to which the shaft is press-fitted and fixed. It is attached.

[0010]

According to the first aspect of the present invention, the first housing in which the mounting recess for mounting the bearing is formed by double drawing of a steel plate, and the second housing in which the mounting recess for mounting the bearing is formed by double drawing of a steel plate. And a predetermined space can be formed. In addition, a stator support cylinder which is formed in a cylindrical shape by drawing of a steel plate and has one end attached to the outside of the attachment recess of the first housing and attached to the first housing while being positioned in a predetermined space. A stator can be attached to the outer periphery of the end.

Further, a magnetic support which is formed along the inner side of the second housing by bending the magnetic steel plate and holds the magnetic body so as to surround the outer periphery of the stator,
It can be attached and fixed to a shaft rotatably inserted and supported by both bearings of the first and second housings. Further, a cylindrical shaft mounting portion extending into the space between both bearings is formed on the magnetic material supporting member, and a vibration isolating rubber is interposed between the shaft mounting portion and the shaft, thereby supporting the magnetic material supporting member. The vibration of the body can be prevented from being transmitted to the shaft.

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

[0013]

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 one embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an outer rotor type brushless DC motor main body (hereinafter referred to as a motor main body), and reference numerals 2 and 3 denote a first housing and a second housing forming a housing of the motor main body 1.

Here, the first housing 2 is formed by drawing a steel plate, and as shown in FIG. 2 which is a sectional view taken along the line A--A in FIG. The mounting recess 4 is formed integrally therewith. The second housing 3 is formed by drawing a steel plate into a cylindrical shape with a bottom, and is integrally formed with a mounting recess 5 which is opened inward on the bottom surface by a double drawing so as to be connected to the first housing 2. It is.

As shown in FIG. 1, a first bearing (bearing portion) 6 and a second bearing (bearing portion) 6a for inserting and supporting a shaft, which will be described later, are fitted into these mounting recesses 4 and 5, respectively. It has become. 2 and 3, reference numeral 21 denotes a rib for attaching the second housing.

In FIG. 1, reference numeral 7 denotes a stator, and reference numeral 8 denotes a magnetic support which is a rotor on which a permanent magnet 9 is mounted. Here, the stator 7 is formed by stacking a plurality of electromagnetic steel sheets punched into a shape having a plurality of teeth as shown in FIG.
Is formed by winding.

The stator core 10 has a plurality of open grooves 10a around which the coil L is wound, as shown in FIG. High-speed winding work of the winding is possible as compared with the winding work of No. Also, this stator 7
The skew is applied and the layers are stacked, whereby the cogging torque is reduced, and the vibration and noise during motor operation can be reduced. On the other hand, the start and end of the winding of the coil L wound around the stator 7 and the terminals of the lead wire are the motor driving electronic components (not shown) of the electronic circuit board 11 attached to the stator insulating portion 7a shown in FIG. Is to be connected to.

As shown in FIGS. 5 and 6, the stator 7 is formed by drawing a steel plate into a cylindrical shape.
One end portion 12A is press-fitted and fixed to the outer periphery of the other end portion 12B of the stator support cylinder 12 which 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 to be press-fitted and fixed is formed in the other end portion 12B of the stator support cylinder 12 by drawing.

Then, the positioning step 12a for positioning is formed in the stator supporting cylinder 12 as described above, and the stator 7 is fixed to the mounting position by pressing the stator 7 against the step 12a at the time of press-fitting. I can do it. Further, by fixing the stator 7 at a fixed position in this way, the deflection of the stator 7 can be prevented, so that the generation of vibration and noise can be prevented, and the magnetic material support specified in the Electrical Appliance and Material Control Law. The space distance from the body 7 can be secured.

The inner diameter of the stepped portion 12a is determined by the outer diameter of the first bearing 6 so that the first bearing 6 can be assembled after the stator support cylinder 12 is fitted and fixed to the first housing 2. It is formed so as to be larger. Further, when the stator support cylinder 12 is fitted and fixed to the outside of the narrowed portion 23 of the first housing 2, the narrowed portion 23 is formed doubly so that it hardly bends toward the mounting recess 4 side. One bearing 6 can be incorporated without damaging it.

On the other hand, the magnetic support 8 is formed by bending a magnetic steel plate along the second housing 3.
An outer annular yoke 8a for mounting and fixing a permanent magnet 9 on the inner periphery as shown in FIG. 1 while being located in a predetermined space formed by combining the first housing 2 and the second housing 3.
A yoke side wall 8b bent from the annular yoke 8a toward a shaft 13 described later;
b and a cylindrical shaft mounting portion 8c formed to extend into a space between the first and second bearings 6 and 6a.

By attaching and fixing the permanent magnet 9 to the inner periphery of the annular yoke 8a as described above, the centrifugal force applied to the permanent magnet 9 when the magnetic support 8 rotates is reduced.
, Whereby the permanent magnet 9 can be prevented from cracking and scattering.

Further, the magnetic support 8 is connected to the second housing 3.
, The thickness in the width direction of the motor body 1 can be reduced, and the shaft mounting portion 8c
Is extended between the two bearings 6 and 6a, thereby utilizing the space between the bearings 6 and 6a to utilize the space between the bearings 6 and 6a.
The thickness in the height direction can be reduced, so that the size of the motor body 1 can be reduced.

The shaft 13 is rotatably inserted into the first and second bearings 6 and 6a, is supported in a double-supported manner, and has a vibration-proof rubber 14 interposed between the shaft 13 and the shaft mounting portion 8c. The magnetic body support 8 is attached and fixed via the. The anti-vibration rubber 14 is used for the shaft 13.
Is press-fitted and fixed between the metal inner sleeve 15 to which the press-fitting is fixed and the shaft mounting portion 8c.
Thus, the shaft mounting portion 8 in which the vibration isolating rubber 14 is provided.
The magnetic body support 8 is attached to the shaft 13 by press-fitting and fixing the shaft 13 to the inner sleeve 15 of FIG.

A knurl (not shown) is formed on the shaft 13 so that the inner sleeve 15 is fixed to the shaft 13 without rotating by the knurl. 13 so that it does not come off.

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. Further, in this embodiment, a water drain 13a is press-fitted into the shaft 13 so as to prevent water droplets from entering 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 at a lower portion.

Next, the assembling operation of the outer rotor type brushless DC motor configured as described above will be described.

To assemble the motor body 1, first, the stator 7 is pressed into the outer periphery of the stator support tube 12 until it hits the stepped portion 12 a and fixed. The stator 7 is fixed to a fixed position by fitting and fixing the outside of 23.

Next, after the preload spring 15 is inserted 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. . Thereafter, one end of the shaft 13 which has been press-fitted in advance into the shaft mounting portion 8c in which the anti-vibration rubber 14 is housed and is integrated with the magnetic body support 8 is inserted through the first bearing 6.

Next, after inserting the second bearing 6 a from the other end of the shaft 13, the second bearing 6 a is moved along the shaft 13 and fitted into the mounting recess 5 of the second housing 3. Thus, the shaft 13 is rotatably inserted and supported by the two bearings 6 and 6a. Finally, the second housing 3 is mounted on the first housing 2 with screws to fix the second bearing 6a fitted in the mounting recess 5 of the second housing 3, and further drained 13a
Into the shaft 13 and cover the mounting recess 5 of the second housing 3 with the waterproof cap 18.

The motor body 1 assembled as described above can be downsized 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 tube 12, and the stator support tube 12 is
The stator 7 can be fixed without being molded by fitting it outside the heavy drawing portion.

Further, by forming the magnetic support 8 by bending a magnetic steel plate along the second housing 3, the motor body 1 can be made thinner. Furthermore, by interposing the vibration isolating rubber 14 between the magnetic body support 8 and the shaft 13, the vibration of the magnetic body support 8 can be prevented from being transmitted to the shaft 13.

In the above description, it has been described that the vibration-proof rubber 14 is press-fitted and fixed between the shaft mounting portion 8c and the inner sleeve 15, but the present invention is not limited to this. 7, the inner sleeve 1
5 and a metal outer sleeve 19 inserted and fixed inside the shaft mounting portion 8c, and press-fitted and fixed between the sleeve body 2
0 may be formed.

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. Then, the shaft 13 is connected as shown in FIG. You may make it attach. This can simplify the trouble of fixing the magnetic body support 8 to the shaft 13 with the rubber vibration insulator 14 interposed therebetween.

[0036]

As described above, according to the present invention, the first housing, the second housing, the stator support cylinder, the magnetic support and the like are formed by drawing, and these components are combined and fixed to form a motor. By doing so, the production is simple and mass production is possible. Further, the stator is press-fitted and fixed in the stator support cylinder, and furthermore, this stator support cylinder is fixedly mounted on the first housing, and vibration isolating rubber is interposed between the stator support cylinder and the shaft, so that vibration can be achieved without molding. And noise can be suppressed. This allows
Small size outer rotor type brushless DC with good workability, low cost and high quality due to manufacturing mainly by press working
Motors can be mass-produced.

[0037]

[Brief description of the drawings]

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor main body 2 1st housing 3 2nd housing 6, 6a Bearing 7 Stator 12 Stator support cylinder 13 Shaft

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02K 29/00 H02K 5/24 H02K 15/14 H02K 21/22

Claims (2)

(57) [Claims] 1. An outer rotor type brushless DC motor in which a rotor on which a magnetic material is mounted rotates around an outer periphery of a stator formed by winding a coil around a plurality of teeth. First having a mounting recess formed by
A housing, having a mounting recess formed by double drawing of a steel plate, a second housing combined with the first housing to form a predetermined space, and a cylindrical shape formed by drawing of the steel plate; One end is the first
A stator support cylinder attached to the outside of the mounting recess formed by double drawing of the housing, and the stator attached to the outer periphery of the other end; and a shape along the inside of the second housing formed by processing a magnetic steel plate. And a magnetic body support that is located in the predetermined space and holds the magnetic body so as to surround the outer periphery of the stator; and the magnetic body support is attached to the mounting recess of the first housing and the second housing, respectively. A first housing-side bearing and a second housing-side bearing; and a shaft rotatably inserted and supported by the two bearings, while the magnetic body support extends into a space between the two bearings. An outer rotor type brushless wherein 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 vibration-proof rubber is press-fitted between a metal outer sleeve inserted and fixed inside the shaft mounting portion and a metal inner sleeve to which the shaft is press-fitted and fixed. The outer rotor type brushless DC motor according to claim 1, wherein: