JPH1118356A - Small-sized axial flow fan motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized axial flow fan motor wherein miniaturization is easily enabled while the wiring space and the arrangement space of electronic components are ensured, by improving the structure of a shaft, a bearing and a bearing holder, and restraining extension in the radial direction. SOLUTION: In this motor, a releasably supporting member 1 is installed on a frame 12, a stator S is arranged in the outer periphery of the member 1, and a rotor R is rotatably arranged via the member 1. The rotor R is releasably supported above the stator S, so that the space in the radial direction of the rotor releasably supporting part is remarkably reduced and extension in the radial direction can be restrained. As a result miniaturization is easily enabled while the winding space and the arrangement space for electronic components are ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small axial fan motor used for information equipment or power supply equipment.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional fan motor. FIG. 5 is a cross-sectional view of a main part of the radial gap type fan motor. In FIG. 5, a bearing holder 23 is disposed on a shaft 21 via a bearing 22. The bearing holder 23 includes a plurality of thin plates such as a silicon steel plate. Is fixedly attached to the core 24.
The armature coil 25 is provided via a core cover to form a stator S.

A field magnet 27 is attached to the inner periphery of a rotor yoke 26 made of a magnetic material through a predetermined gap with the core 24, and the shaft 21 is integrally formed by resin molding. R. The rotor R is formed with a plurality of impellers 28 around the rotor yoke 26 at the same time as the resin molding.
Is formed.

A circuit board 29 has various electronic components 30 mounted thereon. Terminals of the armature coils 25 are connected to a circuit pattern formed on the circuit board 29. Reference numeral 31 denotes a frame disposed so as to cover the outer periphery of the turning space of the impeller 28, and reference numeral 32 denotes a ring mounted on the shaft 21 for preventing the rotor R from coming off.

[0005]

However, in the above configuration, the bearing holder 23 is disposed on the shaft 21 via the bearing 22, and the core 24 and the circuit board 29 must be assembled on the outer periphery of the bearing holder 23. No.
In such a case, the inner diameter of the core 24 and the circuit board 29 is unavoidably increased, and the fan motor inevitably expands in the radial direction, which makes it very difficult to reduce its size. In recent years, a fan motor having a shape of a 20-sided or smaller fan has been demanded in the market, and the conventional configuration cannot cope with it unless the outer diameter of the core 24 is reduced. In this case, the space for the winding portion is lost, which hinders performance. This is the same for the circuit board 29, and it becomes impossible to secure a space for mounting the electronic components 30 and the like.

If the inner diameter of the core 24 becomes large, there is no space for driving the terminal pins into the core cover.
Since the winding terminals must be directly soldered to the circuit board, workability is poor and fixing of the circuit board is unstable.

Therefore, the present invention solves the above-mentioned problems and improves the structure of the shaft, the bearing and the bearing holder, so that the radial expansion can be suppressed. It is an object of the present invention to provide a small-sized axial fan motor that can easily be downsized while securing an arrangement space.

[0008]

According to the present invention, there is provided a small axial flow comprising a support member provided on a frame, a stator disposed on the outer periphery of the support member, and a rotor rotatably disposed via the support member. In the fan motor, the above-mentioned problem is solved by configuring the rotor to be supported above the stator, whereby the radial space of the rotor support portion is significantly reduced to reduce the diameter. Spreading in the direction can be suppressed, and therefore, downsizing can be easily realized while securing space for windings and space for disposing electronic components.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A small axial fan motor according to the present invention has a support member provided on a frame, a stator disposed around the support member, and a rotor rotatably disposed via the support member. In the above-mentioned small axial fan motor, the rotor is rotatably supported above the stator. Preferably, the bearing member is a boss provided integrally with the frame, wherein the rotor is rotatably disposed above the stator by a bearing disposed on the boss.

[0010] The bearing member may be formed by fixing the shaft and / or the resin inner diameter portion press-fitted into the resin inner diameter portion by resin molding of the stator to the frame. Further, the bearing member may be a sleeve-shaped bearing fixed on the frame.

[0011]

FIG. 1 is a longitudinal sectional view of a main part of a radial gap type fan motor according to an embodiment of the present invention, and FIG. 2 is a cross sectional view of a main part of the radial gap type fan motor in FIG. It is. In the figure, reference numeral 1 denotes a boss provided integrally with a resin frame 12 described later as a support member, and a core 4 formed by laminating a plurality of thin plates such as a silicon steel plate around the boss 1. After the core cover is fitted into the core 4, the armature coil 5 is applied to form the stator S.

Reference numeral 2 denotes a bearing disposed on the boss 1 above the stator S constructed as described above, here a ball bearing. A cylindrical rotor yoke 6 rotates on the boss 1 via the ball bearing 2. It is freely supported. A field magnet 7 is provided on the inner periphery of the rotor yoke 6 with a predetermined gap interposed between the core 4 and the rotor yoke 6 to constitute a rotor R. Further, a plurality of impellers 8 made of synthetic resin are provided at equal intervals on the outer periphery of the yoke 6 in the rotor R.

Reference numeral 9 denotes a circuit board on which various electronic components 10 are mounted, and the armature coil 5
Are connected to a circuit pattern formed on the circuit board 9 via terminal pins 11 driven into the core cover 4a. Reference numeral 12 denotes a frame arranged so as to cover the outer periphery of the turning space of the impeller 8.

According to this structure, the rotor bearing portion occupies the radial space, as compared with the conventional case, which includes the shaft, the bearing, and the bearing holder. It can be suppressed. Therefore, the inner diameter of the core and the circuit board can be made smaller, so that the winding space can be increased in the core, and the terminal pins are set on the core cover, and the winding terminals are wound around the terminal pins and soldered. Method can be adopted and workability is good.

Further, the space for mounting components on the circuit board is increased, so that there is no restriction on the arrangement of electronic components, and the shaft of another component can be used as a boss, so that the cost can be easily reduced. In this embodiment, 1
Although two ball bearings are used, two ball bearings may be used.

[0016]

Embodiment 2 FIG. 3 is a longitudinal sectional view of a main part of a radial gap type fan motor according to another embodiment of the present invention. That is, in the same figure, resin is also passed through the inner diameter of the core 4 by the core cover 44a formed of resin together with the core 4, the shaft 13 is pressed into the inner diameter portion, and the shaft 13 and / or the resin inner diameter portion 45a are further inserted. It is fixed to 12 on the frame.

A sintered oil-impregnated bearing 14 is disposed on the shaft 13 above the stator S, and the rotor R is rotatably supported by the sintered oil-impregnated bearing. Other configurations are the same as those in the above-described embodiment, and therefore, are denoted by the same reference numerals and description thereof will be omitted. In this case, the material of the core cover is excellent in fluidity, so that the core cover can be made thin, and the same operation and effect as in the above embodiment can be obtained.

[0018]

Embodiment 3 FIG. 4 is a longitudinal sectional view of a main part of a radial gap type fan motor according to still another embodiment of the present invention.
In this embodiment, a sleeve-shaped sintered oil-impregnated bearing 15 directly fixed to the frame 12 is provided in the same figure, and the stator S is constituted by fixing the core 4 to the outer periphery of the sintered oil-impregnated bearing 15. Together with the sintered oil-impregnated bearing 1
A shaft 13 is rotatably mounted on the inner periphery of the rotor 5 and a rotor yoke 6 is attached to the shaft 13 above the stator S.
, It is possible to configure a rotatable rotor R. Even in this case, the same operation and effect as those of the above embodiment can be obtained, and other configurations are the same as those of the above embodiment.

It should be noted that the present invention is not limited to the above embodiments, but can be implemented with appropriate modifications without departing from the gist of the present invention. For example, in the above embodiment, the radial gap type has been described in detail as an example, but the present invention is not limited to this, and it is needless to say that the present invention can be applied to the axial gap type.

[0020]

As described above, according to the present invention, a support member is provided on a frame, a stator is disposed on the outer periphery of the support member, and a rotor is rotatably disposed via the support member. Since the rotor is configured to be supported above the stator, the radial space of the rotor support can be significantly reduced to suppress the radial expansion, and therefore the inner diameter of the core and the circuit board can be reduced. Since the size can be reduced, the size can be easily reduced while securing a space for windings and a space for disposing electronic components.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a radial air gap type fan motor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part of the radial gap type fan motor in FIG.

FIG. 3 is a longitudinal sectional view of a main part of a radial gap type fan motor according to another embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a main part of a radial gap type fan motor according to still another embodiment of the present invention.

FIG. 5 is a sectional view of a main part of a conventional fan motor.

[Explanation of symbols]

 1 ‥‥ boss 2,14,15,22 ‥‥ bearing 4,24 ‥‥ core 4a ‥‥ core cover 45a ‥‥ resin inner diameter 6,26 ‥‥ rotor yoke 9 ‥‥ circuit board 12 ‥‥ frame R ‥‥ rotor S ‥‥ stator

Claims (4)

[Claims] 1. A small axial fan motor comprising: a support member provided on a frame; a stator disposed on an outer periphery of the support member; and a rotor rotatably disposed via the support member. A small axial fan motor, which is axially supported above the stator. 2. The bearing member according to claim 1, wherein the support member is a boss provided integrally with the frame, and the rotor is rotatably disposed above the stator by a bearing disposed on the boss. 2. The small axial flow fan motor according to 1. 3. The small axial flow fan according to claim 1, wherein the bearing member is formed by fixing the shaft press-fitted to the resin inner diameter portion of the stator by resin molding and / or the resin inner diameter portion to the frame. motor. 4. A small axial fan motor according to claim 1, wherein said bearing member is a sleeve bearing fixed on said frame.