JP2003172300A - Axial flow fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily provide an axial flow fan, at a low cost, capable of coping with humidity resistance, drop-resistance or the like at the time of mounting under a bad environment. <P>SOLUTION: The axial flow fan is provided with a can of a cup shape with bottom shielding a rotation part and a fixed part. A stator of an electric motor and a control circuit part are disposed at an inner surface side of the can and a rotor of the electric motor and an impeller integrally formed therewith are disposed at an outer surface side of the can. The humidity resistance/drop- resistance effect against an energization part is obtained by shielding the stator of the electric motor and the control circuit part against an atmosphere. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axial flow fan, and more particularly to an axial flow fan that requires consideration of dampproofing and dripproofing for current-carrying parts such as a stator of an electric motor and a control circuit section.

[0002]

2. Description of the Related Art FIGS. 6 and 7 are schematic sectional views of an example of a prior art, and FIG. 6 shows a structure in which a control circuit portion of a drive motor is potted. As in the example, the control circuit portion disposed inside the cylindrical portion that is integral with the venturi case 1 is filled / embedded with a resin having excellent thermal conductivity for the purpose of moisture-proof / drip-proof. An example of performing so-called potting processing is known. In this potting process, a window is formed by cutting off a part of the peripheral wall of the cylindrical portion as a passage for a lead wire from the electric motor and drive circuit to be installed, so that the potting material to be filled inside is prevented from flowing out. In addition, there is a problem in that the work of sealing the window portion is forced, the sealing means is processed by a manual work and the like, which requires a large number of man-hours, and the finish at the end of the processing tends to be ugly.

Further, it is a means for improving the moisture-proof / drip-proof structure.
As disclosed in Japanese Patent Application Laid-Open No. 11-324994, which is the applicant of the present application, a part of the open end of the cylindrical part has a cutout part thinned on three sides by improvement of the venturi case, and after the potting treatment, The cutout portion is formed so as to be cutout, and the height of the cutout portion at the opening end of the cylindrical portion from the bottom surface of the cylindrical portion to the rear end portion of the cutout portion is the drive circuit that is internally provided by filling the potting material. The circuit board and the electronic components mounted on the circuit board have a height high enough to be embedded in the circuit board, and are formed in a portion of the plurality of feet near a foot including a groove that serves as a lead-out wire insertion passage. It is also well known to form a concave groove along the wall surface for guiding the lead wire of the electric motor on the inner wall surface of the cylindrical portion.

[0004]

However, in the conventional structure as described above, the potting process for the purpose of preventing moisture and drip can meet the intended purpose, and at the time of the potting process, the filler does not flow out, so that the withdrawal can be prevented. Since it is possible to avoid filling resin in the groove formed in the foot that is the insertion path of the wire, it is possible to eliminate the stain on the appearance, but it is a workability problem related to resin injection in the potting process. There was no change in the need for improvements in points and related costs.

FIG. 7 shows another example of the prior art in which a molding process for covering the energizing parts of the electric motor and the control circuit part with resin is performed. Since these are also well-known techniques, details thereof will be omitted. However, the molding processing method has a problem of causing damage to the coil of the electric motor and electronic components.

[0006]

SUMMARY OF THE INVENTION An axial fan according to the present invention comprises a bottomed cup-shaped isolation can for isolating a stator and a control circuit portion of an electric motor from a rotor of the electric motor and an impeller integrated with the rotor. With the can lid member, the stator of the electric motor and the control circuit part are arranged on the inner surface side of the bottomed cup-shaped isolation can, and the rotating part is arranged on the outer surface side thereof, so that the stator and the control circuit part of the electric motor are exposed to the outside air. It is configured to shield against electricity and to obtain moisture-proof and drip-proof effects on the current-carrying part.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing a first embodiment of an axial flow fan according to the present invention, and FIGS. 2 and 3 are enlarged cross-sectional views of a main part of the example of FIG. FIG. 4 shows a second embodiment of the present invention.
5 is a schematic sectional view of the third embodiment, and FIG. 5 is a schematic sectional view of the third embodiment.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a venturi case 1 comprises a cylindrical wind tunnel 1-1 forming a wind passage and a wind tunnel 1-.
1, a bottomed cup-shaped isolation can 2 supported by a plurality of legs 1-2 extending so as to cross the ventilation passage and having a substantially inverted W-shaped cross section. The bottomed cup-shaped isolation can 2 includes a small diameter cylindrical portion 2-1 and a large diameter cylindrical portion 2
-2, the bearing box 2-3 is formed, but the invention is not limited to the integral molding using the same material as the venturi case 1 as shown in FIG. 1, but as shown in FIGS.
It may be formed as a separate body.

The stator 4 of the electric motor is the bottomed isolation can 2 described above.
The small-diameter cylindrical portion 2-1 of the circuit board 5 has the large-diameter cylindrical portion 2-2.
Are fixedly held by means such as press-fitting or adhesion, and the can lid member 3 is brought into close contact with the open side end 2-4 of the bottomed isolation can 2 via the sealing packings 3-1 and 3-2. Fixed.

The impeller 6 is formed integrally with the rotor 6-1 and the rotary shaft 6-2 of the electric motor, and the bearing 7 is fitted in the bearing box 2-3 of the bottomed cup-shaped isolation can 2. Positioned by the retaining means 8, the rotary shaft 6-2 is rotatably supported.

Sealing box 9 fixed to the can lid member 3
As shown in FIG. 2, the inside is filled with a sealing member 12 such as a compound to prevent breathing of air inside and outside the bottomed cup-shaped isolation can at the lead wire penetrating portion 9-1. belongs to. As shown in the figure, in the lead wire 11 which is inserted through the inside of the sealing box 9, the core wire 11-1 is exposed by removing the clothing inside the sealing box 9, and the core wire 11-1 is sealed in the gap of the core wire 11-1. The stop member 12 is allowed to infiltrate to prevent air from breathing through a slight gap inside the core wire 11-1 and enhance airtightness.

Referring to FIGS. 1, 4 and 5, the air damper 10 fixedly arranged on the can lid member 3 so as to be lined up with the sealing box 9 has an enlarged cross section shown in FIG. It is a means for absorbing a volume change of an internal space formed by a flexible material such as rubber and surrounded by the bottomed cup-shaped isolation can 2 and the can lid member 3. In the internal space of the bottomed cup-shaped isolation can 2 that houses the stator 4 of the electric motor and the control circuit section, the temperature of the internal air rises and volume expansion occurs with the operation of the fan. Since it is surrounded by the bottomed cup-shaped isolation can 2 and the can lid member 3,
The volume expansion of air increases the internal air pressure. Then, when the internal temperature drops to the same temperature as the outside air due to the stop of the operation, the volume expansion subsides. Volume expansion of this internal space. It is clear that repeated contraction hinders the security effect of the bottomed cup-shaped isolation can 2, the can lid member 3, and the sealing box 9. Therefore, the damper opening 10-2 communicates with the outside air so as to absorb the change in the volume of the internal space by changing the volume of the internal space in response to the change in the internal pressure due to the above-mentioned volume expansion, and the bottomed bottom is opened. It is preferably formed as a bellows 10-1 so that its own volume in the internal space surrounded by the cup-shaped isolation can 2 and the can lid member 3 is variable.

As described above, since the sealing box 9 shown in FIG. 2 enhances the sealing effect at the lead wire penetrating portion and suppresses the ventilation of the inside and outside, respectively, the interior of the electric motor which must maintain the insulation is essential. This has the effect of preventing exposure of the stator and the energized parts of the control circuit to the outside air containing moisture and harmful substances.

Further, the air damper 10 shown in FIG. 3 absorbs a change in atmospheric pressure in the internal space to absorb a change in atmospheric pressure in the space surrounded by the bottomed cup-shaped isolation can 2 and the can lid member 3. Therefore, there is an effect of avoiding a respiratory action due to a change in atmospheric pressure.

FIGS. 4 and 5 show another example of the axial flow fan according to the present invention, and the venturi case and the legs are the same as those of the prior art and are omitted.

In the second example, as shown in FIG. 4, the bottomed cup-shaped isolation can 2 has a substantially U-shaped cross section, and a connecting small hole 2-5 is formed at the center of the bottom surface. The bearing box 2-3 in the first example shown in FIG. 1 has a separated shape. The bottomed cup-shaped isolation can 2 is held by a leg 1-2 that is integral with the venturi case 1, and a small-diameter cylindrical portion 2-1 that houses a stator of an electric motor and a circuit board 5 that constitutes a control circuit unit are provided. The large-diameter cylindrical portion 2-2 to be housed is the same as in the first example of FIG. 1 described above, and the can lid body member 3 and the bearing box 3-3 are connected by different materials as shown in the drawing. However, an integrally molded structure made of the same material can be arbitrarily selected.

The can lid member 3 is provided with a sealing box 9 and an air damper 10, and the bearing box 3-3 has a bearing 7 on its inner peripheral surface.
Is fitted and held, and the stator 4 and the circuit board 5 of the electric motor are attached to the outer peripheral surface.
The holding of the same in a predetermined portion is the same as in the above-mentioned first example, but the connecting bell 3-4 at the tip of the bearing box 3-3 causes the connecting small hole 2-of the bottomed cup-shaped isolation can 2 to be held. 5 is different in that it is fixed by fitting with 5.

By connecting the can lid member 3 to the open side end 2-4 of the bottomed cup-shaped isolation can 2, the stator 4 of the electric motor and the power feeding portion of the circuit board 5 are housed in a sealed state.
Further, it is also possible to use an adhesive agent when connecting the can lid member 3 and the bearing box 3-3, and to use a sealing packing 3-1 at the joint portion of the open side end 2-4 of the bottomed cup-shaped isolation can 2. Clearly increasing confidentiality.

Further, FIG. 5 shows a third example. The bottomed cup-shaped isolation can 2 has a substantially U-shaped cross section as in the case of the above-mentioned second example. Instead of 5, V-shaped recess 2 forming a so-called pivot bearing structure
-6 is formed.

The can lid member 3 of the third example holds the stator 4 of the electric motor and the circuit board 5, which correspond to the bearing boxes 3-3 of the first and second examples, at the center thereof. A cylindrical boss 3-5 for forming is formed. The pivot bearing structure of the rotating part including the impeller 6 is formed by the pivot bearing structure formed on the bottom surface of the bottomed cup-shaped isolation can 2 and the outer peripheral surface of the large-diameter cylindrical part of the bottomed cup-shaped isolation can 2. Bearing 7 in contact
It is different in that it is equipped with.

Regarding the configuration of the impeller as an axial fan, the drive motor, and the bearings and bearings,
Needless to say, the present invention is not limited to the example shown and can be arbitrarily and freely selected.

[0022]

As described above, the axial fan according to the present invention is used as a means for dealing with dampproofing and dripproofing in mounting in a severe environment.
By realizing a configuration that can eliminate work processes such as potting processing, workability problems and related cost improvements are realized.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a first example of an axial fan according to the present invention.

FIG. 2 is an enlarged cross-sectional view illustrating the sealing box of the example of FIG.

FIG. 3 is an enlarged cross-sectional view illustrating the air damper of the example of FIG.

FIG. 4 is a schematic sectional view of a second example of the axial fan according to the present invention.

FIG. 5 is a schematic sectional view of a third example of the axial fan according to the present invention.

FIG. 6 is a schematic cross-sectional view of an example of a prior art axial flow fan.

FIG. 7 is a schematic cross-sectional view of a second example of a conventional axial fan.

[Explanation of symbols]

1 Venturi case 1-1 Wind tunnel 1-2 legs 2 bottomed cup-shaped isolation can 2-1 Small diameter cylindrical part 2-2 Large diameter cylinder 2-3 bearing box 2-4 Open side end 2-5 Bonding small hole 2-6 V-shaped concave section 3 Can lid member 3-1 Sealed packing 3-2 Sealed packing 3-3 Bearing box 3-4 Combined bell 3-5 Cylindrical boss 3-6 Cavity 4 Stator of electric motor 5 circuit board 6 impeller 6-1 Electric motor rotor 6-2 Rotation axis 7 bearings 8 retaining means 9 sealed boxes 9-1 Lead wire penetration part 10 air damper 10-1 bellows 10-2 Damper opening 11 lead wire 11-1 Core wire 12 Sealing member

Claims (8)

[Claims] 1. A venturi case having a cylindrical wind tunnel portion, and an impeller integrally formed with a rotor of a drive motor and rotatably supported on the inner peripheral surface of the wind tunnel portion through a small gap. In the axial fan, the venturi case is
A plurality of leg portions extending in the center direction from the cylindrical wind tunnel portion across the ventilation passage, a bottomed cup-shaped isolation can that is integrally held at the leg tips, and a bottomed cup-shaped isolation can. A can lid member that covers the open end, and a stator of the electric motor and a control circuit unit for driving the electric motor are arranged on the inner surface side of the bottomed cup-shaped isolation can, and the outer surface side thereof. The rotor and the impeller are arranged, and the stator of the electric motor and the control circuit portion for driving the electric motor are configured to be shielded from the outside air by the bottomed cup-shaped isolation can and the can lid member. Axial fan characterized by being installed. 2. The can lid member includes a sealing box communicating with the lead wire penetrating portion and having a sealing member filled therein, and the lead wire penetrating portion is sealed by the sealing member. The axial fan according to claim 1, wherein a space formed by the bottomed cup-shaped isolation can and the can lid member is configured to be shielded from the outside. 3. The axial fan according to claim 1, wherein the can lid member is provided with a variable volume air damper having an opening communicating with the outside. 4. The bottomed cup-shaped isolation can has a large-diameter cylindrical portion that communicates with the leg portion and a small-diameter cylindrical portion that communicates with the large-diameter cylindrical portion, and the control circuit portion includes the large-diameter cylindrical portion. The axial fan according to any one of claims 1 to 3, wherein the stator of the electric motor is configured to be housed in each of the small-diameter cylindrical portions. 5. The bottomed cup-shaped isolation can has a cylindrical bearing box that folds back to the center of the bottom and rises, and the bearing box is integrated with the venturi case together with the small diameter cylindrical portion, the large diameter cylindrical portion, and the leg portion. 5. The axial flow fan according to claim 1, wherein the axial flow fan is a resin molded body according to any one of claims 1 to 4. 6. The cup-shaped isolation can having a bottom is formed of a thin metal member, and the open end thereof is fixedly held by the tip of the leg of the venturi case. Axial fan according to any one. 7. The bottomed cup-shaped isolation can has a coupling small hole in the center of the bottom face thereof, and the coupling lid is formed with a bearing box at the tip of the bearing box in the axial direction of the can lid member. The axial fan according to any one of claims 1 to 6, which is configured to be fastened and held by fitting a coupling small hole of the bottomed cup-shaped isolation can and the coupling bell. 8. A bearing box which is integral with the can lid member has an outer peripheral surface formed by AND / OR of the stator of the electric motor.
The axial fan according to claim 7, wherein the inner peripheral surface is formed so as to fit and hold the bearings.