JP2004116290A - Axial fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axial fan for allowing reduction in vibrations/noise in a mounted state without any special additional means. <P>SOLUTION: This axial fan comprises: a venturi case having a cylindrical wind tunnel part and a bearing box; a rotatable impeller opposed to an inner peripheral face of the wind tunnel part through a small air gap and fixed to a rotor shaft; a bearing member pivoting to support the impeller; and a motor comprising a rotor for driving the impeller and a stator opposed to a rotor through a small air gap between an inner peripheral face of the rotor and the stator. An outer circumferential face of a small diameter cylindrical part forming the bearing case is fitted and fixed to an inner peripheral face of the stator through a flexible member formed integrally with the small diameter cylindrical part, AND/OR the inner circumferential face of the small diameter cylindrical part is fitted and fixed to an outer peripheral face of the bearing member fixed to the inner circumferential face of the small diameter cylindrical part through the flexible member. Preferably, the flexible member disposed on the outer circumferential face AND/OR inner circumferential face of the small diameter cylindrical part may be molded integrally with the venturi case by a kind of resin different from venturi case. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
[Industrial applications]
The present invention relates to an axial fan, and more particularly to a vibration suppression improvement of a small axial fan.
[0002]
[Prior art]
[Patent Document 1] (Axial fan: Japanese Patent Application Laid-Open No. 2000-192899)
[0003]
As shown in FIG. 3, since the stator 3-1 is directly fixed and held on the outer peripheral surface of the small-diameter cylindrical portion 1-2 forming the bearing housing, the electromagnetic sound accompanying the energization to the electric motor 3 is directly transmitted to the venturi case 1. The rotor 3-2 of the electric motor, which propagates to the load side via the shaft or forms the rotating part of the axial fan, and the impeller 2 which is integral with the rotor, form a small-diameter cylindrical part 1- forming a bearing housing. 2 and a bearing member, which are connected to each other via a bearing member, and all of these components have rigidity. Therefore, when the rotary unit is driven to rotate, its rotational vibration causes the axial flow fan to be mounted via a bearing box. It is well known that the noise is directly transmitted to the load housing and causes noise during the mounting operation.
[0004]
As a measure for suppressing the above-mentioned noise, when mounting the axial fan, a vibration absorbing member is interposed between the axial fan and the external load-side housing, or for example, in the above-mentioned Patent Document 1 which exemplifies the small-diameter cylindrical portion in FIG. As a countermeasure, the insertion of a ring made of a flexible member between the outer peripheral surface of the small-diameter cylindrical portion 1-2 forming the bearing housing and the stator 3-1 has been proposed, and the respective effects have been realized. Nevertheless, all of these involve the introduction of separate components, which necessitated management disadvantages due to the increase in parts and disadvantages in terms of the number of work processes, and demanded improvements.
[0005]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to realize an axial fan capable of reducing vibration and noise during mounting without requiring any special additional means.
[0006]
[Means for Solving the Problems]
An axial flow fan according to the present invention includes a venturi case having a cylindrical wind tunnel portion and a small-diameter cylindrical portion forming a bearing box, a plurality of blades facing the inner peripheral surface of the wind tunnel portion via a small gap, and the blades implanted therein. An impeller fixedly held on a rotor shaft and rotatably held, a bearing member fitted and held in the bearing box for supporting the impeller, and the blade A rotor mainly composed of a permanent magnet mounted on the inner peripheral surface of the rotor hub for driving a car, and opposed to the inner peripheral surface of the rotor via a small gap, and fixed and held on the outer peripheral surface of the bearing box. And an outer peripheral surface of a small-diameter cylindrical portion forming the bearing housing, an inner peripheral surface of the stator AND / OR, an inner peripheral surface of the same small-diameter cylindrical portion, and an outer peripheral surface of a bearing member fitted to the inner peripheral surface. Are fitted and fixed via a flexible member integral with the small-diameter cylindrical portion. Is configured to be, preferably, a flexible member of the outer peripheral surface AND / OR the peripheral surface of the small-diameter cylindrical portion is integrally molded by the venturi case and heterogeneous resin.
[0007]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0008]
FIG. 1 is a cross-sectional view of an example of an axial flow fan according to the present invention. A small-diameter cylindrical portion 1-2 forming a bearing box has an outer peripheral surface fitted with an inner peripheral surface of a stator 2-1 and a bearing housing. Flexible members 1-21 and 1-22 are integrally formed on both the inner peripheral surfaces to be formed, and both the stator and the bearing member are fixed and held via the flexible members. Have been.
[0009]
In the configuration as described above, the propagation of electromagnetic vibrations and noise generated by energizing the stator 2-1 due to the operation to the small-diameter cylindrical portion 1-2 can be suppressed, and the mass of the rotating portion including the impeller 2 can be reduced. Vibration and noise due to a rotational operation relying on a general unbalance can be suppressed from propagating to the small-diameter cylindrical portion 1-2 via the bearing member.
[0010]
Also, as shown in FIG. 2, the vibration and noise caused by the rotating operation based on the unbalance of the rotating part, which is higher in level than the electromagnetic sound of the stator, are mainly targeted at the small-diameter cylindrical part 1-2. It is practically effective to provide the flexible member 1-22 only on the peripheral surface.
[0011]
Although not shown, in a configuration in which the electromagnetic vibration and noise accompanying the energization of the motor are large due to design restrictions and the like, the main object is to apply the flexible member 1 only to the outer peripheral surface of the small-diameter cylindrical portion 1-2. Placing -21 is also significant.
[0012]
【The invention's effect】
The axial flow fan according to the present invention forms a flexible inclusion in the venturi case itself as a vibration propagation suppressing means, so that vibration and noise reduction in mounting can be realized without requiring special additional means. Can be done.
[Brief description of the drawings]
FIG. 1 is a sectional view of an example of an axial fan according to the present invention.
FIG. 2 is an enlarged cross-sectional view of another example of the small-diameter cylindrical portion forming the bearing box of the axial fan according to the present invention.
FIG. 3 is a cross-sectional view of an example of an axial fan according to the related art.
FIG. 4 is an enlarged explanatory view of a small-diameter cylindrical portion forming a bearing housing in the example of FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Venturi case 1-1 Wind tunnel part 1-2 Small diameter cylindrical part 1-21 whose inner peripheral surface forms a bearing box Flexible member 1-22 integrally formed on outer peripheral surface of small diameter cylindrical part Flexible member 2 integrally formed Electric motor 2-1 Stator 2-2 Rotor 3 Impeller

Claims (2)

A venturi case having a cylindrical wind tunnel portion and a small-diameter cylindrical portion forming a bearing box; a plurality of blades facing the inner peripheral surface of the wind tunnel portion via a small gap; and a rotor hub having the blades implanted and held. A rotatable impeller fixedly held on a rotor shaft, a bearing member fitted and held in the bearing box to support the impeller, and an inner peripheral surface of the rotor hub for driving the impeller Axial fan provided with an electric motor comprising: a rotor mainly composed of a permanent magnet mounted on the rotor; and a stator opposed to an inner peripheral surface of the rotor via a small air gap and fixedly held on an outer peripheral surface of the bearing box. Wherein the outer peripheral surface of the small-diameter cylindrical portion forming the bearing box, the inner peripheral surface of the stator AND / OR the inner peripheral surface of the same small-diameter cylindrical portion, and the outer peripheral surface of the bearing member fitted to the inner peripheral surface are formed by the small-diameter cylindrical portion. It is configured to be fitted and fixed via an integral flexible member. Axial flow fan to be is that, the features. The axial flow fan according to claim 1, wherein the flexible member on the outer peripheral surface AND / OR on the inner peripheral surface of the small-diameter cylindrical portion is integrally molded with a venturi case and a different resin.

Images