JP2002031088A - Axial fan motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an axial fan motor capable of realizing increase of longevity by recovering a lubricating oil and returning it to an inside diametrical part of an oil-retaining sintered metallic bearing even in the case when the lubricating oil splashes in the rotor outside diametrical direction high in circumferential speed. SOLUTION: An inside diametrical inclined surface part 5m is formed on an opening edge part of the inside diametrical part 5h of the oil-retaining sintered metallic bearing 5, respectively a groove part 63 is formed at a position facing against the inside diametrical inclined surface part 5m and an outer peripheral inclined surface part 63a is formed along an outer peripheral surface from the groove part 63 on a shaft body 6 of a rotor, and an oil repellent treated layer 30 not to have a lubricant adhered to it is formed at a position facing against an inside diametrical part 2h of a sleeve holder 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axial fan motor, and more particularly to a CPU and M for small electric equipment such as a notebook personal computer using an oil-impregnated sintered metal bearing as a bearing means.
The present invention relates to a fan motor structure for cooling a PU or the like.

[0002]

2. Description of the Related Art In order to reduce costs, it is effective to use oil-impregnated sintered metal bearings instead of radial ball bearings which account for a large proportion of the total cost. This oil-impregnated sintered metal bearing is obtained by impregnating a porous lubricant with a predetermined lubricant. In order to assemble this bearing to the axial fan motor, it is inserted into a sleeve holder which is insert-molded in the housing body, and then the rotor is inserted, and the rotor is radially supported and set in advance. The thrust washer, which is a thrust bearing, is supported in the thrust direction, and is prevented from coming off by press-fitting the shaft of the rotor into a fitting hole formed in a clip previously set on the thrust washer. Be completed. Further, a retaining ring for stopping lubricating oil leaking from the inner peripheral surface of the sleeve holder on the oil-impregnated sintered metal bearing may be mounted in the groove of the sleeve holder.

Further, a groove is formed in the shaft of the rotor, and the groove is positioned at a chamfered portion formed in the opening of the inner diameter of the oil-impregnated sintered metal bearing so that the groove is formed as the rotor rotates. By causing the lubricating oil to fly in the circumferential direction by the generated centrifugal force, the lubricating oil is collected at the chamfered portion and returned to the inner diameter of the oil-impregnated sintered metal bearing.

[0004]

According to the axial fan motor using the oil-impregnated sintered metal bearing described above, a thrust washer and a clip are inserted into an iron-based sleeve holder, and the oil-impregnated sintered metal bearing is press-fitted. Then, the shaft body insert-molded in the rotor is passed through the inner diameter portion serving as the shaft support portion of the oil-impregnated sintered metal bearing, and the clip is prevented from coming off and completed. For this reason, the end face of the shaft of the rotor is supported by the thrust washer, and the rotor does not directly contact the oil-impregnated sintered metal bearing.

[0005] It is known that the life of an oil-impregnated sintered metal bearing is greatly affected by the presence or absence of a lubricant such as grease or lubricating oil which should be present on the sliding surface of the inner diameter portion. It is important to prevent leakage and scattering.

According to the above-mentioned conventional structure, when the rotor is driven to rotate after completion, the lubricant existing in the inner diameter portion of the oil-impregnated sintered metal bearing passes over the groove of the shaft body, and further, the mounting base of the blade portion inside the rotor. It may flow out to a flat part. Also,
Since the resin shape inside the rotor extends in the radial direction from the root of the rotor and the shaft, lubricating oil is scattered in the outer diameter direction of the rotor having a high peripheral speed. As a result, the amount of lubricating oil impregnated in the oil-impregnated sintered metal bearing gradually decreases, causing seizure between the shaft body and the oil-impregnated sintered metal bearing, resulting in a short motor life.

[0007] Accordingly, the present invention has been made in view of the above problems, and the lubricant existing in the inner diameter portion of the oil-impregnated sintered metal bearing, for example, gets over the groove of the shaft body and further has the blade inside the rotor. Flows out to the flat part of the mounting base of the part,
Even if lubricating oil scatters in the radial direction of the rotor with a high peripheral speed, the lubricant is recovered and returned to the inner diameter of the oil-impregnated sintered metal bearing to provide an axial fan motor that can achieve a longer life. The purpose is.

[0008]

Means for Solving the Problems The above-mentioned problems are solved,
In order to achieve the object, according to the present invention, a rotor integrally provided with a permanent magnet, a plurality of blades, and a shaft supported by an oil-impregnated sintered metal bearing incorporated in a sleeve holder of a housing body. An axial fan motor comprising:
An inner diameter inclined surface portion is formed at an opening edge portion of the inner diameter portion of the oil-impregnated sintered metal bearing, a groove portion is formed on the shaft body at a position facing the inner diameter inclined surface portion, and an outer peripheral inclined surface portion is formed from the groove portion to the outer peripheral surface. It is characterized in that, at a position facing the inner diameter portion of the sleeve holder, an oil-repellent treatment is applied to the mounting base of the shaft and the plurality of blades.

The housing body is formed by insert-molding the sleeve holder, which is continuous with the bottomed portion, from a resin material in order to press-fit and fix the oil-impregnated sintered metal bearing. It is characterized by being insert-molded from a material.

[0010] An annular groove is further formed in the mounting base.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a center sectional view of the axial fan motor. In the figure, AB
The housing main body 1 is molded from a first predetermined resin material such as S resin or polypropylene resin using a mold for injection molding, and the metal sleeve holder 2 is insert molded at the base 1c as shown in the figure. The oil-impregnated sintered metal bearing 5 as a radial bearing is pressed into the sleeve holder 2 and fixed. Instead of the oil-impregnated sintered metal bearing 5, it is also possible to set a radial ball bearing which is expensive but has a long continuous durability time as the bearing means.

By press-fitting and fixing the oil-impregnated sintered metal bearing 5 into the sleeve holder 2 as described above, the metal bearing is press-fitted directly into the housing body 1 molded from the first predetermined resin material. In this case, it is possible to completely prevent the resin cracking caused by the resin deterioration occurring in the case and to prevent the influence of the resin deterioration due to the lubricating oil.

The housing 1 has a frame 1b formed continuously from the base 1c via a support rod (not shown), and an opening 1a between the base 1c and the frame 1b.
Is formed, and air is supplied in the direction of the arrow through the opening 1a.

On the other hand, the stator 11 on which the coil 9 is wound
As shown in the figure, the magnetic change of the annular permanent magnet 8 which is fixed to the housing body 1 around the above-mentioned sleeve holder 2 by bonding and is fixed to the rotor 12 by a Hall element (not shown). Is detected, and the coil 9 is energized based on the detection result to generate a rotating magnetic field and drive the rotor 12 to rotate, thereby forming a so-called brushless motor.

The rotor 12 is provided with the oil-impregnated sintered metal bearing 5 described above.
A shaft body 6 turned from a stainless steel rod member rotatably supported by the above, a permanent magnet 8 magnetically attracted to the stator 11 and a plurality of blade portions 10a are provided integrally on the outer peripheral surface. The upper part of the shaft body 6 is insert-molded to the mounting base 10 as shown.

The shaft body 6 has a groove 63 at a position facing the inclined inner surface 5m of the oil-impregnated sintered metal bearing 5 as shown in the figure.
However, an outer peripheral inclined surface 63a is formed from the groove 63 to the outer peripheral surface as shown.

A clip 4 for holding the shaft body 6 in a retaining state is provided between the lubricating thrust washer 3 made of nylon or Teflon (registered trademark) resin and the oil-impregnated sintered metal bearing 5. It is arranged in the bottomed portion 1d of the main body 1 and is configured to support the axial load of the shaft body 6 with the thrust washer 3 and to support the radial load with the oil-impregnated sintered metal bearing 5. .

The shaft body 6 has a contact end portion 62 having a contact surface 62a for contacting the thrust washer 3;
A small-diameter groove portion 61 having a small diameter is formed by lathing from the vicinity of the contact end portion 62, and the tip-shaped portion 43 of the clip 4 is positioned in the small-diameter groove portion 61 as shown in the drawing, and is subjected to the following steps. Be completed.

Next, FIG. 2A is a plan view of the clip 4, and FIG. 2B is a sectional view taken along line XX of FIG. Figure 1
2, it is recommended in terms of cost and quality that the clip 4 be injection-molded using engineering plastics, which is a second resin material, for example, a polyacetal resin material, but is not limited to this. Alternatively, it can be manufactured using other materials and other manufacturing methods.

The clip 4 has a cylindrical base 41 disposed between the thrust washer 3 and the metal bearing 5 in the sleeve holder 2, and has at least an elastically deformable extension with the cylindrical base 41 as a fulcrum. Two or more petal-shaped extending portions 42 (four in the figure are shown) are integrally formed, and a tip-shaped portion 43 is further integrally formed at the tip. In this tip-shaped portion 43, FIG.
As shown in FIG. 2B, a chamfered portion 43a and a locking portion 43b are formed.

The cylindrical base 41 has a plurality of projections 44 at a portion facing the press-fit side surface of the oil-impregnated sintered metal bearing 5.
(Four places in the drawing) are integrally formed, and the protrusion 44
When the metal bearing 5 is press-fitted by being appropriately crushed,
The extension 42 is not deformed.

FIGS. 3A to 3D are cross-sectional views showing the relationship between the clip 4 and the shaft 6. In this drawing, the same reference numerals are given to the components already described, and the description thereof is omitted. In FIG. 3D, the inner diameter dimension d2 formed by the distal end portion 43 of the clip 4 is in a free state. The diameter of the small diameter groove portion 61 of the shaft body 6 is equal to or larger than the diameter of the
The inner diameter is smaller than the diameter of 2. FIG. 3 (c)
As shown in the drawing, when the elastic portion 4 is elastically deformed around the fulcrum P, the extending portion 4 is larger than the diameter of the contact end portion 62.
2 are integrally formed at the tip.

By configuring the clip as described above,
When the tip of the shaft 6 of the rotor is inserted as shown in FIG. 3A, the force in the direction substantially perpendicular to the direction of the force that the contact surface 62a hits the chamfered portion 43a and pushes in the vertical direction along the longitudinal direction is reduced. And the state shown in FIG.
It further moves downward, and is elastically deformed around the fulcrum P shown in FIG. 3 passes through the abutting end portion 62, whereby the
The state shown in FIG.

In the state shown in FIG. 3 (d), it is possible to achieve a complete non-contact locking state without mechanical interference with the shaft 6, and to prevent cracking and plastic deformation of the clip.

In this way, the rotor can be completely prevented from coming off, and when the shaft 6 is forcibly pulled out as shown in the cross-sectional view of FIG. 4, the locking surface 43b abuts. The inner surface 62c of the end 62 is brought into a state of hitting the inner surface 62c.
d, the shaft 6 cannot be pulled out. Therefore, it becomes impossible to disassemble after assembling.

Next, FIG. 5A is a three-dimensional exploded view showing a manufacturing procedure of the axial fan motor, and FIG.
It is sectional drawing of a jig.

In FIG. 5A, the same reference numerals are given to the components already described, and the description is omitted.
A fixing hole 1f is formed in a frame 1d of the housing body 1 in which the sleeve holder 2 is insert-molded.
Form a mounting part to the device and set the jig table 1
The fixing hole 1f is used for positioning to the position 02.
An inner groove 2a for fixing the retaining ring 7 is formed in the sleeve holder 2, and is set so that the outer dimensions of the retaining ring 7 are reduced and fixed by the inner groove 2a.

On the outer peripheral surface of the oil-impregnated metal bearing, longitudinal grooves 5a (four in the drawing) extending in the longitudinal direction are formed continuously with the lateral grooves 5b. The clip includes a plurality of projections 44 facing the press-fit side surface 5d of the oil-impregnated sintered metal bearing.
have.

By communicating with the vertical groove 5a through the projections 44, the air that has been heated and expanded inside the bottomed portion can be exhausted to the outside.

FIG. 6 is a flowchart showing an assembling procedure. Referring to FIG. 6 and FIG. 5, first, in step S1
Then, the stator 11 having the coil 9 is adhered and fixed to the housing body 1. Also, the thrust washer 3 is set in the sleeve holder 2.

Next, in step S2, the metal bearing 5 is set on the jig 100 shown in FIG.
Then, the clip 4 is set on the jig shaft 101. Also,
In step S4, the jig is placed on the plate 102 and positioned. The preparation for press-fitting the metal bearing is now complete, and the jig 100 is lowered in the direction of the arrow in step S5.
Maintaining a state in which the sleeve holder 2 and a part are fitted,
The jig shaft 101 is lowered by air pressure, and the protrusion 44 is press-fitted and fixed in a partially crushed state by the press-fit side surface 5d. At the time of this press-fitting, the longitudinal groove 5a of the oil-impregnated metal bearing 5
Since an air flow path is formed between the sleeve holder 2 and the sleeve holder 2, a reaction force due to the pumping action does not occur and the press-fitting can be performed smoothly.

Thereafter, in step S6, the press-fit state is visually inspected. If the product is defective, it is discarded in step S11, and if it is non-defective, it is sent to the process following step S7. In step S8, the retaining ring 7 is set to completely prevent the floating of the metal bearing and to prevent the lubricating oil from flowing out, and the process proceeds to step S9, in which the shaft 6 of the rotor 12 is moved as described with reference to FIG. And stop with a clip.

If the product is completed as described above and is energized in step S10 and is a defective product, it is discarded in step S11, and if it is a non-defective product, it is sent to the shipping process and finished.

FIG. 7 is a cross-sectional view of the completed axial fan motor. In the rotating state, the air flows F1 and F2 as shown by broken arrows show the plurality of projections 44 of the clip 4 and the oil-impregnated metal bearing 5 in a rotating state. Between the vertical groove 5a and the horizontal groove 5b.

For this reason, even when the air inside the metal bearing 5 expands due to a rise in temperature, the rotor 12
Is no longer lifted by compressed air.

FIG. 8 is a central sectional view of an axial fan motor having a lubricating oil collecting function. In this figure,
The same reference numerals are given to the components already described and the description thereof is omitted, and the inner diameter portion 5h of the oil-impregnated sintered metal bearing 5 is omitted.
5m is formed at the opening edge of the inner surface. In the shaft 6, a groove 63 is formed at a position facing the inner diameter inclined surface 5m, and an outer inclined surface 63a is formed from the groove 63 to the outer peripheral surface. By causing the lubricating oil to fly in the circumferential direction due to the centrifugal force generated, the lubricating oil is recovered at the inner diameter inclined surface portion 5m, which is a chamfered portion, and returned to the inner diameter portion 5h of the oil-impregnated sintered metal bearing. Further, at a portion facing the inner diameter portion 2h of the sleeve holder 2, the shaft 6
And an oil-repellent treatment layer 30 of a fluorine-based paint over the mounting base 10.
Are formed.

According to the above configuration, the state in which the lubricating oil transmitted above the groove 63 due to the centrifugal force generated by the rotation of the rotor 12 cannot adhere to the oil-repellent layer 30 cannot be maintained. Collides with the inner diameter portion 2h of.
Thereafter, the lubricating oil is transmitted along the retaining ring 7 and is collected at the above-described inclined surface portion 5m at the inner diameter.

Finally, FIG. 9 is a central sectional view showing another embodiment of an axial fan motor having a function of collecting lubricating oil. In this drawing, the same reference numerals are given to the components already described, and the description thereof will be omitted.
Is further formed with an annular groove 10b so that the lubricating oil is collected in the direction of the arrow. With the configuration as described above, the clip 4 is positioned and press-fitted so that a gap is formed between the metal bearing 5 and the clip 4, and at the same time, the projections 44 of the clip 4 are partially crushed and the clip 4 is fixed. 4 can prevent rattling in the thrust direction. In addition, it is possible to suppress the load of the press-in amount of the metal bearing 5 applied to the extending portion by crushing the protrusion 44 of the clip. In addition, vibration and noise could be reduced by preventing backlash.

As described above, the shaft body 6 is insert-molded in the rotor, and the shaft body 6 is provided with the groove 63 in the circumferential direction for preventing leakage of the lubricating oil. Since the rotor is rotated, the lubricating oil flowing into the groove 63 collides with the inner diameter of the oil-impregnated sintered metal bearing by centrifugal force and returns. In addition, since the inner diameter inclined surface portion 5m is formed at the opening edge of the inner diameter portion of the oil-impregnated sintered metal bearing 5, the outer peripheral inclined surface portion 63a is drawn from the low peripheral speed shaft diameter to the high peripheral speed large shaft diameter. As a result, lubricating oil is stored. The lubricating oil is repelled by treating the oil-repellent treatment layer 30 for preventing lubricating oil leakage and scattering, and the lubricating oil flows from the shaft and the root of the rotor to the resin portion having an angle inside the rotor. You can not.

The present invention is not limited to the brushless axial fan motor of the above embodiment, but can be applied to various motors defined in the claims, and an axial fan motor using a brushed motor. The same can be applied to.

[0041]

As described above, according to the present invention,
The lubricant present on the inner diameter of the oil-impregnated sintered metal bearing, for example, gets over the groove of the shaft, flows out to the plane of the mounting base of the blade inside the rotor, and lubricates in the outer diameter direction of the rotor with high peripheral speed. Even if the water is scattered, an axial fan motor can be provided which can recover the lubricant and return it to the inner diameter of the oil-impregnated sintered metal bearing to achieve a longer life.

[Brief description of the drawings]

FIG. 1 is a center sectional view of an axial fan motor.

2A is a plan view of the clip 4 of FIG. 1, and FIG.
FIG. 3 is a sectional view taken along line XX of FIG.

FIGS. 3A to 3D are cross-sectional views illustrating a relationship between a clip 4 and a shaft body 6;

FIG. 4 is a cross-sectional view showing the relationship between the clip 4 and the shaft body 6 after assembly.

5A is an exploded perspective view showing a manufacturing procedure of the axial fan motor, and FIG. 5B is a sectional view of an assembling jig.

FIG. 6 is a flowchart of an assembling procedure.

FIG. 7 is a cross-sectional view of the completed axial fan motor.

FIG. 8 is a center sectional view of an axial fan motor having a function of collecting lubricating oil.

FIG. 9 is a center sectional view of another embodiment of an axial fan motor having a function of collecting lubricating oil.

[Explanation of symbols]

 Reference Signs List 1 housing main body 2 sleeve holder 2h inner diameter portion 3 thrust washer 4 clip 5 oil-impregnated sintered metal bearing 5m inner diameter inclined surface portion 5h inner diameter portion 6 shaft body 7 retaining ring 8 permanent magnet 10 mounting base 12 rotor 30 oil-repellent treatment layer 63 groove 63a outer periphery Inclined surface

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F04D 29/52 F04D 29/52 B 5H607 F16C 17/02 F16C 17/02 Z 5H615 17/08 17/08 33/10 33 / 10 AZ H02K 5/167 H02K 5/167 AB 7/08 7/08 Z 7/14 7/14 A 15/14 15/14 A F term (reference) 3H022 AA03 BA01 BA04 BA06 CA01 CA13 CA41 CA50 CA54 DA07 DA13 DA17 DA19 3H033 AA02 BB02 BB08 BB20 CC01 CC03 CC06 DD17 DD25 DD26 EE05 EE11 EE14 3H034 AA02 BB02 BB08 BB20 CC01 CC03 CC06 DD22 DD24 DD28 EE05 EE11 EE14 3J011 AA07 BA02 MA02 BB01 MA02 BB02 DD09 EB05 EB06 EB09 EB13 EB26 EB28 EB33 EC08 FF06 GG04 5H607 BB01 BB09 BB14 BB17 BB25 DD02 DD03 DD09 DD14 DD15 FF04 GG01 GG05 GG07 GG09 GG28 JJ06 5H615 AA01 BB01 SS19 PP19 BB07 SS19 PP19

Claims (3)

[Claims] 1. An axial fan motor having a rotor integrally provided with a permanent magnet, a plurality of blades, and a shaft supported by an oil-impregnated sintered metal bearing incorporated in a sleeve holder of a housing body. Forming an inner diameter inclined surface portion at an opening edge portion of the inner diameter portion of the oil-impregnated sintered metal bearing; and forming a groove in the shaft body at a position facing the inner diameter inclined surface portion, and an outer peripheral slope from the groove portion to the outer peripheral surface. An axial fan motor, wherein a face portion is formed, and an oil repellent treatment is applied to a portion of the shaft body and a plurality of blade portions at a position facing an inner diameter portion of the sleeve holder. 2. The housing body is formed by insert-molding the sleeve holder, which is continuous with a bottomed portion, from a resin material to press-fit and fix the oil-impregnated sintered metal bearing from a resin material. The axial fan motor according to claim 1, wherein the axial flow fan motor is insert-molded from a material. 3. The axial fan motor according to claim 2, wherein an annular groove is further formed in the mounting base.