JP2004239188A - Centrifugal fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To calm the air flow from the suction to the discharge. <P>SOLUTION: The centrifugal fan according to the present invention is provided with a casing, a multi-vane impeller rotatably pivoted within the casing, an impeller boss that is opposite to a suction port center section of the casing at the inner side of the multi-vane impeller, and a drive motor installed in the impeller boss. The head of the impeller boss has a spherical face, which is preferably formed with an arcuate face of which center diameter is larger than one fourth of the diameter of the impeller boss and a flat face connected thereto, or a flat face of which diameter is smaller than a half of the diameter of the impeller boss at the center of the head of the impeller boss and a spherical surface connected to the periphery of the flat face. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a centrifugal fan, and more particularly to a quiet centrifugal fan having a reduced thickness.
[0002]
[Prior art]
[Patent Document 1] Title of the invention; Centrifugal fan JP 10-037894 [Patent Document 2] Title of the invention; Centrifugal fan impeller JP 11-013690 [0003]
Improvements related to the calming of centrifugal fans have been diversified by expanding the applications involving miniaturization and thinning. Many of the improvements related to the multi-blade impeller, which is a noise generation source associated with the above, target the setting of the blade shape based on the fluid dynamics and the arrangement of the blades.
[0004]
As a configuration of the multi-blade impeller, an impeller boss linked to an axis is provided in order to hold a large number of wings arranged in a cylindrical shape as a rotating body. As described above, since the drive motor is housed in the inside thereof, it is formed in a cup shape, and its flat head faces the intake port of the centrifugal fan. A part of the central portion strikes the imperabos head at an acute angle.
[0005]
As described above, the operation sound of the centrifugal fan is caused not only by the impeller of the impeller, but also by the noise related to the impeller boss due to the turbulence of the intake air. In addition, raising the rigidity of the impeller boss is a subject to be studied, and it is also necessary to improve the noise dissipation by the impeller boss shape as described above and shown in FIG. Has emerged.
[0006]
[Problems to be solved by the invention]
Although the conventional configuration as described above has achieved a corresponding effect, the need for practical improvement does not stop, and it is desired that even small improvements can be achieved by further accumulation of quietness. It was the fact that there was no change in the situation.
[0007]
[Means for Solving the Problems]
A centrifugal fan according to the present invention includes a casing, a multi-blade impeller rotatably supported inside the casing, an impeller boss inside the multi-blade impeller and opposed to a central portion of a suction port of the casing, and It has a drive motor or an impeller type motor having an impeller boss as a rotor hub, and sucks air from a suction port of the casing, and applies centrifugal force to intake air based on rotation of the multi-blade impeller. A high-pressure air is discharged from a discharge port formed on a part of the outer peripheral surface of the casing, and the impeller boss has a spherical surface at its head, and preferably has a diameter in the central portion exceeding 1/4 of the impera boss diameter. A flat surface formed of a spherical surface and a flat surface communicating therewith, or a flat surface formed at the center of the imperabos head with a diameter of 1/2 or less of the imperabos diameter and a spherical surface communicating with the periphery thereof. It is formed such that Ri.
[0008]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0009]
FIG. 1 is a cross-sectional view of an essential part of an example of a centrifugal fan according to the present invention. As the drive motor, an epimotor drive motor having an imperabos as a rotor hub is used. The entire structure of the centrifugal fan using the external rotation type driving motor is a well-known technology, and therefore the description thereof will be omitted.
[0010]
In this example, the entire head of the imperabos facing the intake port has a spherical surface, and as is apparent from comparison with FIG. 5 showing the prior art, the head shape of the imperabos is characteristic. .
[0011]
In the example shown in FIG. 1, since the impeller boss head is formed as a spherical surface, it goes without saying that the flow of the intake air is smooth as shown by the arrow in the figure.
[0012]
In this configuration, as shown in FIG. 2, the vibration generated when the impeller is exposed to the flow of the intake air and the radiation of the noise due to the rotating operation of the built-in electric motor are dispersed in all directions. It is connected.
[0013]
FIG. 3 shows a second example of the present invention, in which the shape of the impeller boss is formed as a spherical surface at the center and a flat surface at the periphery communicating with the spherical surface.
[0014]
Also in this example, as is clear from comparison with FIG. 5 showing the above-described prior art, the smoothness of the flow of intake air is ensured, and as shown in FIG. This is based on the example of FIG.
[0015]
In the second example, the imperabos head has a central spherical surface and a flat surface communicating with the periphery thereof, and the spherical surface having a diameter larger than 1/4 of the imperabos diameter is effective. Has been confirmed.
[0016]
Although illustration and detailed description are omitted, the same effect can be obtained even when the impeller boss head has a small flat surface in the center and a spherical surface communicating with the periphery thereof. It has been confirmed that the diameter is preferably １ ／ or less of the imperabos diameter.
[0017]
Further, in the above-described embodiment, the driving motor is an abduction motor in which the rotor hub also serves as the impeller boss and the rotor main body is fixed and held inside the impeller boss. As a matter of course, it goes without saying that a drive motor that is separate from the imperabos is also applied to a configuration that is installed in the imperabos.
[0018]
【The invention's effect】
With the configuration described above, the centrifugal fan according to the present invention realizes smoothing of the flow of air from the intake air to the exhaust air and noise reduction by dispersing the related noise distribution of Imperabos.
[Brief description of the drawings]
FIG. 1 is a sectional view of a main part showing an example of a centrifugal fan according to the present invention.
FIG. 2 is a diagram illustrating the dispersion of noise dissipation in the example of FIG. 1;
FIG. 3 is a sectional view of a main part showing another example of the centrifugal fan according to the present invention.
FIG. 4 is a diagram illustrating the dispersion of noise dissipation in the example of FIG. 3;
FIG. 5 is a sectional view of an essential part showing an example of a conventional centrifugal fan.
FIG. 6 is a diagram illustrating noise dissipation in the example of FIG. 5;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Casing 1-1 Inlet 2 Multi-blade impeller 2-1 Imperabos 2-11 Head 2-111 Spherical surface 2-112 Flat surface 2-113 Peripheral part 3 Drive motor

Claims (5)

A casing, a multi-blade impeller rotatably supported inside the casing, an impeller boss formed inside the multi-blade impeller, and a drive motor housed in the impeller boss; Air is suctioned from a suction port formed on one side wall, and centrifugal force is applied to the suction air by the rotation of the multi-blade impeller, and high-pressure air is discharged from a discharge port formed on a part of the outer peripheral surface of the casing. Centrifugal fan, wherein the head of the impeller boss facing the center of the suction port of the casing has a spherical surface. The head of the imperabos has a central spherical surface and a flat surface communicating with the periphery thereof, and the diameter of the spherical surface is formed with a size exceeding 1/4 of the imperabos diameter, The centrifugal fan according to claim 1, wherein The head of the imperabos has a central flat surface and a spherical surface communicating with the periphery thereof, and the diameter of the flat surface is formed to be equal to or less than の of the imperabos diameter. The centrifugal fan according to claim 1, wherein 4. The drive motor according to claim 1, wherein the rotor hub is also an impeller boss, and the drive motor is an abduction type motor in which a rotor main body is fixed and held inside the impeller boss. 5. Centrifugal fan. The centrifugal fan according to any one of claims 1 to 3, wherein a separate drive motor is fixedly held inside the impeller boss.

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