JPH07213017A - Axial fan - Google Patents

Abstract

PURPOSE:To suppress the vibration of a motor, which is transmitted to a boss part and to rotating wings through a shaft as low as possible, by a method wherein the boss part is composed of an inside boss and an outside boss and a vibration-proof part between them. CONSTITUTION:An axial fan 10 attached to a shaft 12 is roughly composed of an inside boss 20, a vibration-proof part 22 and an outside boss 24. The inside boss 20 and the vibration-proof part 22 are molded together into one, piece. A step 30 is provided on the vibration-proof part 22 at about the center part in an axial direction and the small diameter part 32 of the vibration-proof part 22 is formed on the shaft tip 12a side of the step 30 and the large diameter part 34 is formed on the opposite side of the step 30. If the axial fan 10 is put onto a shaft 12, it is positioned by a stopper member 18 and, in that state, a nut 52 is screwed onto the shaft tip 12a to fix the axial flow fan 10 to the shaft 12. As a result, a vibration transmit ted to the inside boss 20 is attenuated by the vibration-proof part 22 and the vibration transmitted to wings attached to the outside boss can be minimized.

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 having a vibration isolation structure.

[0002]

2. Description of the Related Art Conventionally, an axial fan is provided for the purpose of cooling the inside of machinery such as office automation equipment.

Referring to FIG. 5, a conventional axial fan (100)
The structure of will be briefly described. In the figure, the code (101) is
A shaft extending from a motor (not shown). In the vicinity of the tip (101a) of the shaft (101), the axial fan (10
0) is pivotally attached at its boss (102). The boss (102) has a cylindrical shape, and an axial flow is formed by the boss (102) and a plurality of blades (104) extending radially outward from the outer peripheral surface (103) of the boss (102). A fan (100) is configured.

The boss (102) is on one side (right side in FIG. 5).
The stopper (105) mounted on the shaft (101)
Positioned by the shaft (101) on the other side
It is positioned by a nut (106) screwed to the tip portion (101a) of the.

Therefore, when the motor drives and the shaft (101) of the motor rotates, the boss (102) rotates and the blades (104) rotate.

[0006]

SUMMARY OF THE INVENTION An axial fan having the above structure.
(101) had the following problems. That is, while the motor is being driven, the vibration of the motor is
1) to the boss (102) and rotating blades (10
4). When the vibration is transmitted to the blade (104), the vibration is amplified and a large noise is generated.
In addition, the amplified vibration causes a large load to be applied to the bearing supporting the shaft (101) via the shaft (101), which causes the life of the bearing to be shortened.

[0007]

[Means for Solving the Problems] Therefore, the following means were taken to solve the above problems. That is, the axial fan according to claim 1, the inner boss portion having an insertion hole in which the shaft of the motor is arranged, the inner boss portion axially attached to the shaft of the motor, and the outer peripheral surface of the inner boss portion. The anti-vibration section is provided on the upper side, and the outer boss section is provided on the outer peripheral surface of the anti-vibration section and to which the blade is attached.

It is preferable that the inner boss portion and the vibration isolating portion are integrally molded.

Further, as in claim 3, the vibration-proof portion and the outer boss portion can be fixed by a holding plate.

According to a fourth aspect of the present invention, it is preferable that the pressing plate has a screw hole at a position corresponding to the outer boss portion and an insertion protrusion at a position corresponding to the vibration isolating portion. .

According to a fifth aspect, it is preferable that the inner boss portion has a prismatic shape.

According to a sixth aspect of the present invention, an extension portion projecting in the shaft axial direction (direction in which the shaft extends) from the end portion of the vibration isolation portion on the side of the inner boss portion on which the motor is disposed or on the side opposite thereto. Can be provided.

[0013]

In the axial fan according to the first aspect of the present invention, since the boss portion is composed of the inner boss portion and the outer boss portion having the vibration isolating portion in the middle, even if the vibration of the motor is generated in the inner boss portion. Even if it is transmitted, it is damped by the vibration isolator,
Vibrations to the vanes attached to the outer boss are minimized.

As a result, there is no fear that the vibration will cause a large amount of noise, and there is no concern that a large load will be applied to the bearing that supports the shaft.

There are no particular restrictions on the material forming the vibration isolator, and rubber, synthetic resin, etc. may be mentioned, but it is preferable to use rubber from the standpoint of vibration isolation performance.

In the axial fan according to claim 2,
Since the inner boss portion and the vibration isolating portion are integrally molded, it is not necessary to align the two when the axial fan is assembled, and the work efficiency is improved. Further, it is possible to prevent the positional displacement between the two while the axial fan is being driven, which leads to improvement in performance.

In the axial fan according to claim 3,
Since the vibration isolating portion and the outer boss portion are fixed by the pressing plate, it is possible to prevent the positional deviation between the two during the driving of the axial fan.

In the axial fan according to claim 4,
The anti-vibration portion and the outer boss portion can be fixed easily and reliably by the pressing plate.

In the axial fan according to claim 5,
Since the inner boss portion has a prismatic shape, there is no possibility that the inner boss portion will idle around the anti-vibration portion, and the rotation of the shaft can be reliably transmitted to the anti-vibration portion (and thus the outer boss portion). it can.

The above-mentioned "rectangular prism" includes a triangular prism, a quadrangular prism, a pentagonal prism, a hexagonal prism, an octagonal prism and the like.

In the axial fan according to claim 6,
Since the inner boss portion is provided with an extension portion projecting in the axial direction of the shaft from the end portion of the vibration isolation portion on the side where the motor is arranged or on the side opposite thereto, the work of attaching the axial fan is facilitated. Become.

That is, after the shaft is inserted through the insertion hole of the inner boss portion of the axial fan, the nut is screwed on the tip of the shaft to position the axial fan as described in the prior art. However, when tightening the nut, it is necessary to hold the blade of the axial fan or the outer boss portion by hand so that the torque of the nut does not rotate the axial fan.

However, as described above, since the vibration isolating portion made of rubber or the like is arranged between the inner boss portion and the outer boss portion, the torque of the nut is applied to the blade or the outer boss portion by hand. In the case of receiving it by holding it, there is a risk that the vibration isolating portion will be bent by the torque and will hinder the installation work of the axial fan. Therefore, if the torque is received by holding the extension portion with a tightening tool such as a wrench or a spanner, the nut can be securely tightened to the end without adversely affecting the axial fan such as bending due to the vibration isolator. it can.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

1 to 3, reference numeral (12) is a shaft of a motor (not shown). The tip (12a) of the shaft (12) is provided with a screw groove (14) for screwing a nut described later. Further, the shaft (12) is provided with a circumferential groove (16) extending in the circumferential direction at a position separated from the tip portion (12a) by a desired dimension,
An annular stopper member (18) is fitted in the circumferential groove (16).

The axial fan (10) axially attached to the shaft (12) is roughly divided into an inner boss portion (20), a vibration damping portion (22), and an outer boss portion (24). There is.

The inner boss portion (20) has a hexagonal columnar shape and is made of a metal such as iron or copper. The inner boss portion (20) has an insertion hole (26) in which the shaft (12) is arranged. Further, two fitting grooves (28) extending in the circumferential direction are provided at a predetermined interval.

The vibration isolator (22) has a cylindrical shape and is made of rubber. This anti-vibration part (22) is the inner boss part (20).
Is disposed on the outer peripheral surface. The above-mentioned inner boss portion (20) and the vibration isolation portion (22) are integrally molded. Further, the vibration isolator (22) has a step (30) at a substantially central portion in the axial direction, and a small diameter portion (32) is formed from the step (30) to the shaft tip (12a) side. A large diameter portion (34) is formed on the opposite side. As shown in FIG. 2, on the side surface (36) of the large-diameter portion (34) on the side where the motor is arranged, insertion holes into which insertion protrusions of a pressing plate described later are fitted at predetermined circumferential intervals. (38) is provided at four places.

The outer boss portion (24) has a cylindrical shape and is made of a metal such as iron or copper. The outer boss portion (24) is arranged on the outer peripheral surface of the vibration isolator (22) so as to match the outer surface shape of the vibration isolator (22).
A plurality of blades (25) are attached to the outer boss portion (24) by welding. Further, on the side surface (40) of the outer boss portion (24) on the motor disposition side, four screw holes (42) are provided at predetermined circumferential intervals.

The inner boss portion (20) and the anti-vibration portion (22) are integrally molded as described above. The vibration-proof part (22) and the outer boss part (24) are made up of a metal holding plate (44).
Fixed by.

The holding plate (44) is made of, for example, a metal disc body, and has an insertion hole (44) through which the shaft (12) passes in the center.
a) is provided. The holding plate (44) has insertion protrusions (44) protruding in the axial direction of the shaft at predetermined circumferential intervals at an inner edge portion formed by the insertion hole (44a).
b) is provided four times, and further four screw holes (44c) are provided so as to penetrate the holding plate (44) in the thickness direction.

After the vibration damping portion (22) integrally molded with the inner boss portion (20) is fitted inside the outer boss portion (24), the outer boss portion (44) is constructed by the pressing plate (44) having the above-mentioned structure. 2
4) Fix the anti-vibration part (22). That is, the presser plate (4
After inserting the screw (50) into the screw hole (44c) in 4), it is inserted into the screw hole (42) of the outer boss portion (24) and screwed. At the same time, the insertion protrusion (44b) of the holding plate (44) is inserted into the insertion hole (38) provided in the vibration isolator (22). As a result, the anti-vibration unit (2
2) and the outer boss (24) are fixed.

The axial fan (10) having the above structure is inserted into the shaft (12). At this time, since the stopper member (18) is provided on the shaft (12) as described above, when the axial fan (10) reaches the position of the stopper member (18), the axial fan (10) Is positioned by the stopper member (18). In this state, if the nut (52) is screwed on the tip (12a) of the shaft (12), the axial fan (1
0) can be attached to the shaft (12). In addition,
Reference numeral (53) is a washer. Shafts (12)
In order to reliably transmit the rotation of the shaft to the axial fan (10), an elongated notch (13) extending in the axial direction is provided at the shaft tip (12a), and the inner boss (20) also has the notch (13). ) Elongate notch (21)
And a fitting plate (23) is press-fitted into the space formed by both notches (13) and (21) (see FIG. 1).

As described above, the axial fan (1
In (0), since the boss portion is composed of the inner boss portion (20) and the outer boss portion (24) having the vibration damping portion (22) in the middle, even if the vibration of the motor is caused by the inner boss portion (20). ), The vibration is reduced by the vibration isolator (22), and the vibration to the outer boss (24) is minimized.

As a result, there is no fear that the vibration will be amplified by the blades (25) and noise will increase, and there will be no concern that a bearing (not shown) that supports the shaft (12) will be heavily loaded. .

The vibration-proof part (22) and the outer boss part (24) are fixed on one side only by the pressing plate (44), but the invention is not limited to this and can be fixed on both sides. In this case, the step (30) provided on the vibration isolator (22) is not always necessary.

Further, as described above, the pressing plate (44) is provided with the insertion projection (44b) and is inserted into the vibration isolator (22), but it may be screwed instead.

It is also possible to separately provide the inner boss portion (20), the vibration isolating portion (22) and the outer boss portion (24) and integrate them by adhesion.

Further, as shown in FIG. 4, the shaft tip end side of the inner boss portion (20) is projected in the same direction as the shaft axial direction (the direction in which the shaft (12) extends), and the inner boss portion ( An extension (60) can be provided on 20). This facilitates tightening of the nut (52). That is, when the nut (52) is fastened to the tip portion (12a) of the shaft (12), the outer boss portion (24) or the blade (25) may be held by hand to receive the torque generated when the nut is tightened. Although it is possible, as described above, since the vibration isolation part (22) is arranged between the inner boss part (20) and the outer boss part (24), the torque is applied to the outer boss part (24) or the blades. If it is received by (25), the vibration isolator (22) may bend and it may be difficult to tighten the nut (25).

However, if the torque is received by holding the extension portion (60) with a tightening tool such as a wrench or a spanner, adverse effects such as bending due to the vibration isolator (22) will be exerted on the axial fan (10). The nut (52) can be securely tightened to the end without any damage.

Although the extension portion (60) is provided on the shaft tip end side of the inner boss portion (20), it is not limited to this and may be provided on the side opposite to the shaft tip end side.

[0042]

According to the axial fan of claim 1,
The vibration transmitted to the inner boss portion is damped by the vibration isolator, and the vibration to the blades attached to the outer boss portion is minimized. As a result, there is no fear that the vibration will be amplified and noise will increase, and there is no concern that a large load will be applied to the bearing that supports the shaft.

According to the axial flow fan of the second aspect, since the inner boss portion and the vibration isolator are integrally molded, it is necessary to align the two when the axial flow fan is assembled. Work efficiency is improved. Further, it is possible to prevent the positional displacement between the two while the axial fan is being driven, which leads to improvement in performance.

According to the axial fan of the third aspect, since the vibration isolator and the outer boss are fixed by the retainer plate, displacement of the axial fan is prevented during driving of the axial fan. can do.

According to the axial fan of the fourth aspect, the vibration proof portion and the outer boss portion can be easily fixed by the pressing plate.
And surely.

According to the axial fan of the fifth aspect, since the inner boss portion has a prismatic shape, the inner boss portion does not run idle with respect to the vibration isolation portion, and the rotation of the shaft is ensured. Can be transmitted to the anti-vibration part (and thus the outer boss part).

According to the axial fan of the sixth aspect, the mounting work of the axial fan becomes easy.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an axial fan according to an embodiment of the present invention. However, the blades are omitted.

FIG. 2 is an enlarged perspective view of an anti-vibration portion integrally molded with an inner boss portion as viewed from a shaft insertion side.

FIG. 3 is a vertical sectional view showing an assembled state of FIG.

FIG. 4 is a vertical cross-sectional view showing an assembled state of an axial fan according to another embodiment.

FIG. 5 is a vertical cross-sectional view showing an assembled state of a conventional axial flow fan.

[Explanation of symbols]

 10 ... Axial fan 12 ... Shaft 20 ... Inner boss 22 ... Anti-vibration part 24 ... Outer boss 25 ... Blade 26 ... Insertion hole 44 ... Holding plate 44a ........ (of holding plate) Screw hole 44b …… Insertion protrusion (of pressing plate) 52 …… Nut 60 …… Extended part

Claims (6)

[Claims] 1. An inner boss portion having an insertion hole in which a shaft of a motor is arranged, a vibration isolator arranged on an outer peripheral surface of the inner boss portion, and an anti-vibration portion arranged on an outer peripheral surface of the vibration isolator. And an outer boss portion provided with blades attached thereto. 2. The axial flow fan according to claim 1, wherein the inner boss portion and the vibration isolating portion are integrally molded. 3. The axial fan according to claim 1, wherein the vibration isolator and the outer boss are fixed by a retainer plate. 4. The pressing plate has a screw hole at a position corresponding to the outer boss portion, and an insertion protrusion at a position corresponding to the vibration isolating portion. Axial fan. 5. The axial flow fan according to claim 1, wherein the inner boss portion has a prismatic shape. 6. The inner boss portion is provided with an extension portion projecting in an axial direction of the shaft from an end portion of the vibration isolation portion on a side where the motor is disposed or on a side opposite to the side where the motor is disposed. The axial fan according to any one of Items 1 to 5.