JP2002242896A - Axial fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an axial fan capable of improving the conventional problem in terms of the working environment where adhesive as a chemical substance is used or the difficulty in decomposition to be made for recycling of resources. SOLUTION: The axial fan is equipped with a venturi case 1 having a cylindrical wind tunnel 1-1 and a minor diametric cylindrical portion 1-2 to form a bearing box, an impeller 2 having a plurality of blades confronting the inside circumferential surface of the wind tunnel with a minor gap interposed in between and a rotor hub 3 in which the blades are implanted, coupled fast with a rotor shaft 8 and borne rotatably by a bearing member fitted in and held by the bearing box, and a motor 6 consisting of a rotor whose main member is a permanent magnet 5 attached fast to the inside circumferential surface of the rotor hub for driving the impeller and a stator arranged mating with the rotor with a minor gap interposed in between, wherein the stator is held by the means of screw engagement of the female threaded inside surface of the stator with the male threaded outside surface of the minor diametric cylindrical portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axial fan, and more particularly to an improvement of a small axial fan.

[0002]

2. Description of the Related Art FIG. 6 is a sectional view of an example of a brushless DC fan according to the prior art, in which a rotor having a permanent magnet 5 held by a cup-shaped rotor hub 3 integral with an impeller 2, and
A stator core 6-1 which faces the inner peripheral surface of the rotor permanent magnet 5 via a small gap and is wound with a winding to form a stator 6; the stator core 6-1 is a Venturi It is fixed to and held on the outer peripheral surface of the small-diameter cylindrical portion 1-2 that forms an integral part with the case 1 and forms a bearing housing.

In this example, the bearing box 1-2 is formed as an inner peripheral surface of a small-diameter cylindrical portion 1-2 for holding a stator core 6-1 of the electric motor 6, and in order to secure stability during rotational driving, The bearing members 9 are fitted to step portions provided near both ends, and the rotor shaft 8 is disposed so as to penetrate the both bearing members 9. The rotor permanent magnet 5 integrally held via the rotor hub 3 faces the outer peripheral surface of the stator core 6-1 via a small gap, and is rotatably supported by the rotor shaft 8. .

As described above, the small-diameter cylindrical portion 1-2 integral with the venturi case 1 has an inner peripheral surface formed as a bearing box and an outer peripheral surface fixedly holds the stator core 6-1. Adhesion or press-fitting is frequently used for both fixing means, and the fixing means depends on fixing and holding.

[0005]

SUMMARY OF THE INVENTION The above-mentioned conventional constructions have been improved in terms of work environment problems in handling adhesives as chemical substances and difficulties in disassembly related to resource recycling. Was expected.

[0006]

An axial fan according to the present invention faces a venturi case having a cylindrical wind tunnel portion and a small-diameter cylindrical portion forming a bearing housing via a small gap to the inner peripheral surface of the wind tunnel portion. An impeller having a plurality of blades and a rotor hub in which the blades are implanted, is connected and fixed to a rotor shaft, and is rotatably supported by a bearing member fitted and held in the bearing box, An electric motor comprising a rotor mainly composed of a permanent magnet fixed to the inner peripheral surface of the rotor hub for driving the impeller, and a stator opposed to the rotor with a small gap therebetween. And a configuration in which the stator is held by screwing the female screw-forming inner peripheral surface of the stator with the male screw-forming outer peripheral surface of the small-diameter cylindrical portion. A female screw with the same specifications as the female screw formed on the The cylindrical member is screwed into the male screw forming portion of the outer peripheral surface of the small-diameter cylindrical portion so that the cylindrical member comes into contact with the stator end surface, and the axially pressed state of the two members is in the axial direction. It is configured to function as a rotation direction restraining means (so-called double nut) of the stator.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

[0008]

1 is a sectional view of an example of an axial fan according to the present invention. The difference from the example of the prior art shown in FIG. 6 is that a small diameter cylinder forming a stator core 6-1 and a bearing box is provided. It is a means for bonding and fixing to the part 1-2.

[0009] As shown in the figure, the maintenance of the fastening force in the rotating direction is not only the so-called double nut fixing force due to the contact crimping of the small-diameter cylindrical portion 1-2 step portion and one end surface of the stator core, but also Any auxiliary means can be invoked.

FIG. 4 is a sectional view showing a second embodiment of the present invention. The first embodiment is formed on the inner peripheral surface of the stator core shown in FIG. The female member 6-12 is used in combination with the cylindrical member 10 having the female screw 10-1 of the same specification.

In this configuration, the cylindrical member 1 used in combination is
The press-contact state between the end face 0 and the other face of the stator iron core produces a double nut effect, and exerts an effect on strengthening the fastening force in the rotation direction.

[0012]

The axial-flow fan according to the present invention can improve the working environment by eliminating the need for an adhesive which is a chemical substance when manufacturing the fan, and can also improve the resource recycling by facilitating disassembly. Has been realized.

[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 a sectional view illustrating a stator core according to the example of FIG. 1;

FIG. 3 is a side view illustrating a small-diameter cylindrical portion of the venturi case according to the example of FIG. 1;

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

FIG. 5 is a sectional view illustrating a cylindrical member according to FIG. 4;

FIG. 6 is a sectional view of an example of an axial fan according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Venturi case 1-1 Wind tunnel 1-2 Small diameter cylindrical part (bearing box) 1-21 Outer peripheral surface of small diameter cylindrical part 1-22 External thread forming part of outer peripheral surface of small diameter cylindrical part 2 Impeller 3 Rotor hub 3-1 Cylindrical Part 4 Back yoke 5 Permanent magnet 6 Electric motor 6-1 Stator core 6-11 Inner peripheral surface of stator core 6-12 Internal thread forming part of inner peripheral surface of stator core 7 Control circuit 8 Rotor shaft 9 Bearing member 10 Double nut 10-1 Internal thread forming part on inner peripheral surface of cylindrical member

Claims (2)

[Claims] 1. A venturi case having a cylindrical wind tunnel portion and a small-diameter cylindrical portion forming a bearing box, a plurality of blades opposed to the inner peripheral surface of the wind tunnel portion via a small gap, and a rotor having the blade installed therein. An impeller fixedly connected to a rotor shaft and rotatably supported by a bearing member fitted and held in the bearing box; and a rotor hub for driving the impeller. In an axial fan including an electric motor including a rotor having a permanent magnet as a main member fixed to an inner peripheral surface thereof and a stator disposed to face the rotor with a small gap therebetween,
A female screw is formed on the inner peripheral surface of the stator, and a male screw is formed on the outer peripheral surface of the small-diameter cylindrical portion. An axial flow fan, wherein the stator is held in some cases. 2. A cylindrical member having a female screw having the same specification as a female screw formed on the stator is provided on an inner peripheral surface thereof, and the cylindrical member is brought into contact with the stator end surface so that the cylindrical member comes into contact with the stator end surface. The small-diameter cylindrical portion is screwed to the external thread forming portion on the outer peripheral surface, and the pressure contact state in the axial direction of both is configured to function as rotation direction restraining means (so-called double nut) of the stator. The axial flow fan according to claim 1, wherein