JP2004144033A - Duct fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a duct fan for solving problems of lowering of air flow pressure, an increase in noise and easy accumulation of dust between a motor and an impeller in the duct fan provided with the impeller having an opening part. <P>SOLUTION: This impeller 12 sucks air from an axis direction and blows air in the axis direction. In the impeller 12, a substantial cup type main plate 11 partially opened is provided, and a substantial cup type cover 13 adjacent to the main plate 11 and having an opened distal end part is installed on the impeller 12 side of the motor 6 rotating and driving the impeller 12 between the motor 6 and the main plate 11. By this constitution, lowering of blast pressure, the increase in noise and easy accumulation of dust between the motor 6 and the impeller 12 are prevented. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a duct fan mainly used for ventilation of a building.
[0002]
[Prior art]
A conventional example will be described with reference to FIGS.
[0003]
A conventional duct fan 101 includes a tubular outer frame 102, an electric motor 105 having a drive shaft 104 fixed to the outer frame 102 by mounting feet 103 at an inner central portion of the outer frame 102, It is configured by an impeller 107 having a plurality of blades 106 inserted and fixed to a drive shaft 104 of 105.
[0004]
The impeller 107 has a main plate 108 for connecting the plurality of blades 106 to be integrated as the impeller 107, and the main plate 108 is provided at a central portion thereof with a blade boss for inserting and fixing to the drive shaft 104 of the electric motor 105. In addition to the portion 109, the blade boss portion 109 has a bowl-like shape with the periphery as the top and a bend that approaches the electric motor 105 toward the outer periphery.
[0005]
The plurality of blades 106 have a smooth curved surface to guide the air sucked from the central front portion in the blade central axis direction in the blade lateral axis direction and to efficiently send the air rearward along the cylindrical shape of the outer frame 102. It has a shape.
[0006]
Further, an impeller 107 including a main plate 108 and a plurality of blades 106 is integrally formed of a resin material.
[0007]
When the impeller 107 is integrally molded, the direction in which the mold is removed is in the direction of the drive shaft 104. In order to mold the curved surfaces of the plurality of blades 106 smoothly, the mold of the axial portion of the blade curved surface is formed on the main plate 108. Space is required, and consequently, openings 110 along the blades 106 are provided in the integrally molded portions of the plurality of blades 106 of the main plate 108 by the number of blades 106.
[0008]
That is, the main plate 108 has a bowl-like shape having an opening 110 that is partially cut open at the root of the integrated smooth curved blade 106.
[0009]
On the other hand, the end face of the electric motor 105 on the side of the impeller 107 is a flat surface, and the space between the above-mentioned main plate 108 having the opening 110 and the bowl shape is large around the drive shaft 104 of the electric motor 105, As the distance from the shaft 104 increases in the circumferential direction, the diameter sharply decreases.
[0010]
In such a configuration, when the impeller fixed to the drive shaft of the electric motor is rotated, air is sucked from the blade central axis direction by a plurality of blades provided on the impeller, and the blade wheel rearward from the blade side axis direction. It will be blown to.
[0011]
The above is the configuration of the conventional example.
[0012]
As for the prior art documents, there is no accumulation of the technology related to the invention claimed in the present application, and there is no prior art document information to be described.
[0013]
However, the following is merely a reference in terms of configuration.
[0014]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 8-128869 (FIGS. 1, 5, 6, and 8)
[0015]
[Problems to be solved by the invention]
In such a configuration of the conventional duct fan, the air sucked from the suction side of the front center portion of the impeller, which is rotationally driven by the electric motor via the drive shaft, is guided by the blade to the outside in the circumferential direction of the impeller and is boosted. However, at this time, since there is an opening in the main plate behind the blade, all air is not sent to the blade, and some air passes through the opening in the main plate and leaks to the downstream side of the main plate. . That is, a part of the air does not reach the outer side in the circumferential direction of the impeller by the blade and is discharged with insufficient pressure. For this reason, there is a problem that a required pressure is not generated when the fan is used as a duct fan. If the rotation speed of the electric motor, that is, the rotation speed of the impeller is increased to generate the required pressure, noise is increased.
[0016]
The present invention solves such a problem, and prevents the air pressure due to the rotation of the impeller from being insufficiently increased. Therefore, it is not necessary to increase an extra rotation speed to increase the pressure, and the noise is reduced. It is an object of the present invention to provide a duct fan that does not increase the power consumption.
[0017]
In addition, dust is mixed in the air to be blown by the duct fan. Among the dust, the dust in the air leaking from the opening of the main plate of the impeller to the motor side is flat on the impeller side of the motor. It often accumulates on the surface. When the accumulated dust reaches a certain amount, it may be blown and discharged at once, or may contain oil and water and flow from the inside of the duct fan to the outside, causing a deterioration of the product image and the appearance of the product. Although it is necessary to clean the duct fan, it is very difficult to clean the duct fan.
[0018]
An object of the present invention is to solve such a problem and to provide a duct fan in which dust is not accumulated as much as possible on an impeller side of an electric motor so as to eliminate cleaning as much as possible. It is.
[0019]
[Means for Solving the Problems]
In order to achieve the above object, the duct fan of the present invention has, as one means, an impeller that sucks from the axial direction and blows in the axial direction, wherein the impeller has a substantially bowl-shaped main plate that is partially open. In addition, between the electric motor that rotationally drives the impeller and the main plate, a substantially bowl-shaped cover that is close to the main plate and that has an open end is provided on the impeller side of the electric motor.
[0020]
According to the present invention, by providing the substantially bowl-shaped cover near the partially-opened substantially bowl-shaped main plate of the impeller, air leakage from the opening of the main plate is suppressed, and the center of the impeller is Most of the air sucked in from the front is boosted and blown by the blades, which results in a high static pressure, low noise duct fan, and suppresses air leakage from the main plate opening. Since the shape of the cover close to the main plate is substantially the same as that of the main plate, the above-mentioned leaked air can flow smoothly without stagnation.Therefore, there is almost no adhesion of dust to the cover. Since it is installed in between, it is possible to obtain a duct fan having a configuration in which dust does not easily accumulate on the electric motor.
[0021]
Another means is that the cover is integrated with the mounting foot of the electric motor and attached to the duct fan body.
[0022]
According to the present invention, as described above, by providing the substantially bowl-shaped cover close to the partially-opened substantially bowl-shaped main plate of the impeller, air leakage from the opening of the main plate is suppressed, and Most of the air sucked from the front of the center of the car is boosted by the blades and blown, resulting in a high-volume, low-rotation, high-static-pressure, low-noise duct fan, and a main plate opening. Since the leakage of air from the main plate is suppressed and the cover shape close to the main plate is almost the same as the main plate, the above-mentioned leaked air can flow smoothly without stagnation, so there is almost no dust adhesion to the cover In addition, since the cover is provided between the motor and the impeller, not only a duct fan having a configuration in which dust is less likely to accumulate on the motor is obtained, and further, the mounting foot of the motor and the cover are integrated. This In, reducing the manufacturing cost increase without increasing the number of parts, or in which the duct fan can reduce manufacturing costs is obtained.
[0023]
Another means is that the cover is bonded and fixed to the impeller by bonding or screwing, and is rotated together.
[0024]
According to the present invention, the cover is joined and fixed to the substantially bowl-shaped main plate which is partially opened in the impeller, so that the opening of the main plate is substantially eliminated, so that the air leaks from the opening. And all the air sucked from the front of the center of the impeller is boosted and blown by the blades, so that a duct fan with higher air flow, lower rotation, higher static pressure and lower noise can be obtained, and the main plate opening Since there is no air leakage from the section, a duct fan with almost no dust attached to the electric motor can be obtained.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention relates to an impeller for sucking from the axial direction and blowing in the axial direction, wherein the impeller has a substantially bowl-shaped main plate that is partially opened, and an electric motor that rotates and drives the impeller and the main plate. In between, a substantially bowl-shaped cover close to the main plate and having an open end is provided on the impeller side of the electric motor.
[0026]
At this time, when the impeller rotates, the suction air is sucked up by the blade and pressurized, but tends to leak to the motor side having a lower pressure than the partial opening of the main plate.
[0027]
However, between the electric motor and the main plate, a substantially bowl-shaped cover close to the main plate and having an open end is installed on the impeller side of the electric motor, so that the air pressurized by the blades is directed to the electric motor side. This prevents the blade from going, and as a result, the amount of leakage from the blade side to the electric motor side is reduced, so that the phenomenon that the pressure rise caused by the blade is reduced is reduced, and the performance is reduced. This effect is greater as the distance between the main plate and the cover is smaller.
[0028]
Further, since the air leaking to the back surface of the impeller contains dust, if the amount of air leakage is small, the amount of dust carried is also reduced, so that the dust accumulated on the impeller side of the electric motor is reduced. The volume is also reduced by the reduction in leakage. Further, since the shape of the main plate is substantially bowl-shaped, cleaning becomes easy.
[0029]
Another means is that a substantially bowl-shaped cover is formed integrally with the mounting foot of the electric motor, and is attached to the main body of the duct fan. This not only prevents the substantially bowl-shaped cover from leaking air from the opening of the main plate and reduces the pressure, but also allows the cover and the cover to be formed by integrally forming the motor-mounted mounting feet and the bowl-shaped cover that are usually attached. Since the motor mounting foot is one component, the number of components is not increased, so that an effect of reducing the manufacturing cost can be obtained.
[0030]
Another means is such that a substantially bowl-shaped cover shaped to fill the opening of the main plate of the impeller is fixed to the impeller by bonding or screwing, and is rotated together. As a result, there is no opening in the main plate of the blade, so that the air pressurized by the blade does not leak, resulting in high pressure, and low noise without the need to increase the rotation speed to compensate for the reduced pressure due to the leak. Further, the impeller is composed of two parts, a main plate and a blade. However, as compared with the case where these two parts are integrally formed, the cost of the mold and the number of man-hours are reduced.
[0031]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0032]
【Example】
(Example 1)
As shown in FIGS. 1 and 2, the duct fan 1 has an outer frame 4 having a cylindrical inside and a bell mouth 3 provided at an air suction port 2, and a drive shaft 5 at a central portion of the inner portion of the outer frame 4. An electric motor 6 is provided, and the electric motor 6 is fixed to the outer frame 4 with screws (not shown) by two mounting feet 7 connecting the electric motor 6 and the outer frame 4.
[0033]
In this embodiment, the motor is fixed to the outer frame with two mounting feet so that the air flow resistance is as small as possible. However, the number of mounting feet is reduced to four depending on the size and weight of the motor. In some cases, the resin may be fixed to the outer frame by screwing the resin shape into the outer frame so as to be assembled and fixed.
[0034]
Next, seven blades 8 are connected to the tip of the drive shaft 5 of the electric motor 6, and the blades boss 9 for connecting and fixing the seven blades 8 to the electric motor drive shaft 5 is integrally formed in the axial direction. An impeller 12 having a bowl-shaped main plate 11 having seven openings 10 along the bend of the blade 8 is inserted and fixed as much as possible.
[0035]
Here, the number of blades is as in the present embodiment, and depending on the size of the impeller, there may be less or more than seven blades. However, the number of openings in the main plate is the same as the number of blades.
[0036]
The impeller 12 is located near the bell mouth 3 of the air suction port 2 of the outer frame 4, sucks air from the center front in the axial direction of the impeller 12, and blows air to the rear side in the axial direction.
[0037]
The main plate 11 of the impeller 12 has a blade boss portion 9 at the center for insertion and fixing to the drive shaft 5 of the electric motor 6, and the further toward the outside from the blade boss portion 9 in the circumferential direction, the closer to the electric motor 6. It has a bowl shape with a bend that approaches it.
[0038]
Therefore, the space between the main plate 11 and the electric motor 6 is maximum near the blade boss portion 9 at the center of the main plate 11, and becomes narrower and smaller as going outward.
[0039]
The outer periphery of the bowl shape of the main plate 11 of the impeller 12 is slightly larger than the outer periphery of the electric motor 6, so that the high-speed airflow sent backward from the blade 8 hits the electric motor 6 so as not to obstruct the smooth air flow. ing.
[0040]
A cover 13 is provided in a space between the main plate 11 of the impeller 12 and the electric motor 6.
[0041]
The cover 13 is provided with an opening 14 near the drive shaft 5 of the electric motor 6 so as to escape the drive shaft 5 and the blade boss 9 of the main plate 11. It has a shape with a smooth curved surface up to the front edge side end surface 15. Although this shape is also a bowl shape, the radius of curvature is slightly smaller than that of the bowl shape of the main plate 11 of the impeller 12, and therefore, although it is along the bowl shape of the main plate 11 of the impeller 12, the electric motor 6 The distance between the bowl-shaped surface of the main plate 11 and the bowl-shaped surface of the cover 13 increases as approaching the front edge side end surface 15 of the cover 13. This is because the amount of the air leaking from the opening 10 of the main plate 11 gradually increases along the circumferential direction, so that the increased amount of the air flows smoothly.
[0042]
Further, the cover 13 can be fitted and fixed to the front edge side end face 15 of the electric motor 6 from the drive shaft 5 side before inserting and fixing the impeller 12 to the drive shaft 5 of the electric motor 6.
[0043]
As described above, the configuration of the present embodiment is significantly different from the conventional example, particularly in that the cover is provided between the main plate of the impeller and the front end surface of the electric motor.
[0044]
In the above configuration, when the impeller 12 is rotationally driven by the electric motor 6, the air sucked from the front center of the impeller 12 is guided by the blade 8 to the side of the impeller 12 at high speed and is pressurized. Since the air pressure of the motor 11 on the motor 6 side is smaller than the increased pressure of the impeller 12, the air pressure tends to leak to the motor 6 through the opening 10 in the main plate 11.
[0045]
However, between the main plate 11 and the electric motor 6, a substantially bowl-shaped cover 13 having an open end is provided on the impeller 12 side of the electric motor 6 so as to be close to the main plate 11. Is prevented from going to the electric motor 6, as a result, the amount of leakage from the blade 8 side to the electric motor 6 side is reduced, the phenomenon that the pressure rise caused by the blade 8 is reduced is reduced, and the performance deterioration is suppressed. Therefore, the decrease in pressure is small and the number of rotations to be increased to compensate for the decrease in pressure is small, so that the noise rise is small.
[0046]
Here, the amount of air leaking from the opening 10 of the main plate 11 of the impeller 12 becomes smaller as the distance between the main plate 11 and the cover 13 becomes smaller. Is also reduced.
[0047]
In addition, since the air leaking to the motor 6 side of the impeller 12 contains the dust 16, if the amount of air leakage is small, the amount of the dust 16 carried is also reduced. The amount of dust 16 that accumulates on the side of the vehicle 12 also decreases due to the reduction in the amount of leakage. Further, since the shape of the cover 13 is substantially a bowl shape bulging toward the impeller 12, the dust 16 is less likely to collect dust 16 than when the impeller 12 of the conventional electric motor 6 is dented toward the electric motor 6, so that cleaning is easy. Things.
[0048]
As a result, the noise can be reduced by about 2 dB and the pressure can be increased as compared with the conventional type without the cover.
[0049]
In addition, the effect with respect to the conventional is the same whether the material of the blade plate is made of resin or metal.
[0050]
FIG. 3 shows an example in which the size of the cover 13 in the first embodiment is different, and the size of the bowl shape is small and the effect of improving the performance is small, but it is less expensive than a large cover. The effect of facilitating cleaning is the same.
[0051]
(Example 2)
FIG. 4 shows a cover 13 according to the first embodiment, in which the cover 13 is integrally formed with the mounting foot 7 of the electric motor 6, and the cover 13 is an integral mounting foot cover 17 that can be screwed and fixed to the outer frame 4 of the duct fan 1. In addition, since it is integrally formed with the same components as the conventional mounting foot 7, the manufacturing cost is lower than the case where the cover 13 is newly provided as in the first embodiment. Thus, the substantially bowl-shaped mounting foot integrated cover 17 not only reduces the air leakage from the opening 10 of the main plate 11 to prevent a pressure drop, but also prevents the mounting foot 7 of the motor 6 normally mounted and the mounting foot 7 of the first embodiment. By integrally forming the bowl-shaped cover 13 as described above, the cover and the motor mounting foot become one part, so that the number of parts is not increased, and the effect of reducing the manufacturing cost is obtained.
[0052]
(Example 3)
FIG. 5A shows a state in which the cover 13 in the first embodiment is an embedded type cover 18 that can be embedded in the main plate 11, and shows a state before being fixed to the impeller 12 by bonding or screwing. Then, an embedded type cover 18 that fills the opening 10 of the main plate 11 of the blade 8 is bonded or screwed and fixed as shown in FIG. 5B. In this case, since the air pressurized by the blade 8 has substantially no opening 10 in the main plate 11 of the impeller 12, the air does not leak, the air becomes high in static pressure, and the rotation speed is increased to compensate for the reduced pressure due to the leak. There is no need to make it extremely low noise. Further, although the impeller 12 has two parts, the embedded type cover 18 and the main plate 11, the mold cost and the man-hour cost can be reduced as compared with the case where these two parts are integrally formed.
[0053]
【The invention's effect】
As is apparent from the above embodiments, according to the present invention, in the duct fan, between the electric motor and the main plate having the opening, the main plate is close to the main plate, and a substantially bowl-shaped cover having an open end is provided with the electric motor. By installing on the side of the impeller, it is possible to suppress performance degradation such as pressure drop and to improve the cleaning performance. In addition, by fixing the substantially bowl-shaped cover to the main plate by adhesion, it is possible to prevent a decrease in performance. In addition, by integrally molding with the motor mounting foot, it is possible to suppress an increase in manufacturing cost.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a duct fan according to a first embodiment of the present invention. FIG. 2 is a top view of the impeller. FIG. 3 is a cross-sectional view of a duct fan having the same shape and a reduced cover. FIG. 5A is a cross-sectional view of a duct fan according to a second embodiment of the present invention before the cover is mounted, and FIG. 5B is a cross-sectional view of the duct fan before the cover is mounted according to the third embodiment of the present invention. FIG. 7 is a sectional view of a conventional duct fan. FIG. 7 is a top view of the impeller.
DESCRIPTION OF SYMBOLS 1 Duct fan 6 Electric motor 10 Opening 11 Main plate 12 Impeller 13 Cover 16 Dust 17 Mounting foot integral cover 18 Embedded type cover

Claims (3)

In an impeller that suctions air from the axial direction and blows in the axial direction, the impeller has a substantially bowl-shaped main plate that is partially open, and the impeller is rotated between an electric motor that drives the impeller and the main plate. A duct fan having a configuration in which a substantially bowl-shaped cover close to a main plate and having an open end is installed on the impeller side of an electric motor. The duct fan according to claim 1, wherein the cover is integrated with a mounting foot of the electric motor and is attached to the duct fan body. The duct fan according to claim 1, wherein the cover is fixed to the impeller by bonding or screwing, and is rotated together.

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