JP2595403Y2 - Axial fan motor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an axial fan motor provided in various OA equipment and the like.

[0002]

2. Description of the Related Art In a case where a large number of electronic circuits are accommodated in a casing, such as various OA equipments, there is a possibility that heat generated by the electronic components is trapped and the electronic components are damaged. Therefore, a ventilation hole is provided in the side wall of the casing, and an axial fan motor is attached to the ventilation hole to release the heat inside the casing to the outside.

The structure of a conventional axial fan motor is as follows.
There is one described in Japanese Patent Application Laid-Open No. H4-172932. The axial fan motor described in this publication uses a hermetic type bearing as a bearing for supporting a shaft serving as a center of rotation. As described above, a sealed bearing (double shielded ball bearing) is generally used as the bearing of the axial fan motor.

[0004]

In the axial fan motor, it is preferable to use a sealed type bearing for the purpose of preventing the grease used for lubricating the shaft from scattering during rotation. Hermetically used sealed bearings are expensive and may be of excessive quality depending on the application of the fan motor.

The present invention has been made in view of this point, and uses an inexpensive open-type bearing which is most frequently used, and which is free from grease for lubrication during rotation. It is an object to provide a fan motor. And, two bearings are arranged in the axial direction so that the rotation of the shaft is stable and the rotating shaft does not vibrate. For the lubrication that oozes from each bearing by covering the outside of the two bearings The grease can be effectively prevented from scattering to the outside.

[0006]

According to the present invention, as a means for solving the above-mentioned problems, a shaft is rotatably supported by inner rings of two bearings arranged in an axial direction, and an impeller is mounted on the shaft. In the axial fan motor, the two bearings are open, the center boss of the impeller connected to the shaft is formed in a cup shape, and the boss and one end of the shaft are fitted. And integrated with the mating part
The inner ring of one of the two bearings
Annular with coil springs to provide preload
A ridge is provided, and an annular protrusion is provided on the outer peripheral side of the boss portion of the impeller.
A ridge is provided in the axial direction to support the two bearings.
A ring for interposing the coil spring at one end of a bearing housing
Between the ridges in the shape of a circle and the ridges provided on the outer peripheral side of the boss portion
And an annular ridge in the axial direction to form a labyrinth structure as further by mounting an end cap covering the end of the bearing housing, Beari the end caps of two said
Support the outer ring of the other bearing in the thrust direction
And the end cap and the labyrinth structure provide a closed structure for covering the two bearing portions.

[0007]

[Function] With such a configuration, it is formed by three ridges.
Since the labyrinth structure covers the outer part of one bearing, even if the lubricating grease oozes from between the inner ring and outer ring of the bearing during rotation of the shaft, this is blocked by the labyrinth structure and Will not scatter. Also, since the outer part of the other bearing is covered with the end cap, even if the lubricating grease oozes from between the inner ring and the outer ring of the bearing while the shaft is rotating, this is blocked by the end cap and Will not scatter.

[0008]

FIG. 1 shows an embodiment of the present invention. Reference numeral 1 denotes a bearing box as a fixed-side member, which has a flange portion 2 and an upright portion 3 located at the center thereof as shown in the figure. The upright portion 3 includes two bearings 4 disposed vertically, that is, in the axial direction of a shaft 11 described later.
5 is supported by fitting. Bearing 4,5
Is an open type (unshielded type ball bearing). A stator core 9 provided with a winding 8 is fitted to the outside of the upright portion 3 of the bearing housing 1 and is fixed by fixing means (not shown).

The printed circuit board 6 includes a winding 8 and a stator core 9.
It is supported by an insulator 10 inserted into the stator core 9 to insulate it from the core. An electronic circuit as a DC brushless motor and a set of components thereof are mounted on the printed board 6 (not shown). Reference numeral 7 denotes a lead wire for supplying power to the electronic circuit. Winding 8
Is supplied with a current from the electronic circuit, and the stator core 9 emits changing magnetic lines of force.

The inner rings of the bearings 4 and 5 support the shaft 11. Thereby, the shaft 11 becomes rotatable with respect to the bearing housing 1. The tip of the shaft 11 projects from the bearing 4, and the central portion of the boss 13 of the impeller 12 is integrated with the projecting portion by fitting. The boss portion 13 is substantially cup-shaped, and a plurality of fans 1
4 are mounted radially.

A portion of the boss portion 13 where the shaft 11 is fitted has an annular ridge 15 directed toward the bearing 4. A coil spring is provided between the inner portion of the ridge 15 and the inner ring of the bearing 4. 16 are interposed in a compressed state. The coil spring 16 applies a preload in the thrust direction to the shaft 11 via the inner ring of the bearing 4 . For this reason, a retaining ring 17 whose inner surface is in contact with the inner ring of the bearing 5 is fitted into the lower portion of the shaft 11 so that the shaft 11 does not come off in the upper part of the figure.

An inner wall of a portion of the boss 13 of the impeller 12 to which the fan 14 is attached is connected to the above-described insulator 10.
There is a space at an appropriate distance from the outer periphery of the boss 13, and a ring-shaped magnet 19 is held in this portion of the boss 13 via a ring-shaped yoke 18. As shown in the figure, a slight gap is formed between the magnet 19 and the winding 8, and a magnetic interference between the magnet 19 and the stator core 9 is performed in this gap.

On the outer peripheral side of the boss portion 13, the insulator 10
The portion adjacent to the winding 8 has an annular ridge 20 toward the winding 8 side.
And supports two bearings 4, 5
A coil spring 16 is interposed at one end of the bearing housing 1
An annular ridge 15 is provided. In addition,
An annular ridge 21 is formed on the upright portion 3 so as to face the ridge 20.
Has been established. And these two annular ridges 20, 1
5 and ridges 21 located therebetween and projecting from the opposite side
As a result, a labyrinth structure is formed.

[0014] lower portion of the upright portion 3 of the bearing housing 1 is in a hole 22 for passing the shaft 11, but the end cap 23 is mounted in the bore 22, when covering the end portion of the shaft 11 together
To support the outer ring of the bearing 5 and position it in the thrust direction.
Decisions are made.

Also in the axial fan motor having such a configuration, the electronic circuit receives a supply of electric power from the lead wire 7 to supply a control current to the winding 8, and the interference between the magnetic force line changed by the electric current and the magnetic force line of the magnet 19. As a result, the generation of a rotational force on the impeller 12 is the same as that of the conventional one.

The rotation center of the impeller 12 is the shaft 11
Since the shaft 11 is supported by the inner rings of the bearings 4 and 5, when the shaft 11 rotates, the inner rings of the bearings 4 and 5 also rotate integrally. When rotating, the lubricating grease filled between the inner ring and the outer ring may bleed. In the axial fan motor of the present invention, the bearings 4 and 5 are hermetically sealed by the labyrinth structure formed by the ridges 20 , 21 and 15 at the upper part in the figure of the shaft 11 and by the end cap 23 at the lower part. Even if grease oozes, it does not scatter outside.

As described in the above embodiment, both shafts 11
Since the end is surrounded by an end cap 23 and a hermetically sealed structure of a labyrinth structure formed by ridges 20, 21, and 15, even if the lubricating grease oozes from the bearing 4 , the end is surrounded by an external force. Does not scatter. Also,
Grease from bearing 5
It does not scatter outside even if it bleeds. If a liquid sealant is applied to the labyrinth part, the effect can be further enhanced.

[0018]

[Effects of the Invention] The present invention is an axial fan motor configured as described above. Therefore, the present invention is generally used with a simple structure in which only an end cap and a labyrinth structure are provided at the tip of the shaft. Even if an open type bearing is used, it is possible to effectively prevent the grease for lubrication from scattering to the outside. In addition, if one of them has a labyrinth structure, even if a respiratory action of the bearing occurs due to the rotation of the shaft, it can be absorbed. Since the structure is simple, it can be implemented at low cost. In the case where two bearings are arranged in the axial direction so that the rotation of the shaft is stable and the rotating shaft does not vibrate, the outside of the two bearings is covered. This makes it possible to effectively prevent the grease for lubrication from scattering outside. With a labyrinth structure
Did you cover the outside of the bearing with the end cap?
The bearing can be positioned.
Workability at the time of attachment is remarkably improved. And with a simple structure
The grease can be prevented from scattering.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bearing box 4 Bearing 5 Bearing 11 Shaft 12 Impeller 13 Boss part 14 Fan 20 Protrusion 21 Protrusion 23 End cap

──────────────────────────────────────────────────続 き Continued on the front page (56) References JP-A-2-254952 (JP, A) JP-A-4-208054 (JP, A) JP-A-4-34871 (JP, U) JP-A-3-348 50955 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H02K 5/10 H02K 5/15-5/173 H02K 7/08 H02K 7/14 A

Claims (1)

(57) [Scope of request for utility model registration] 1. An axial fan motor in which a shaft is rotatably supported by inner rings of two bearings disposed in an axial direction and an impeller is mounted on the shaft, wherein the two bearings are open. The boss at the center of the impeller connected to the shaft is formed in a cup shape, the boss and one end of the shaft are fitted and integrated, and the two bases are attached to the fitted portion.
Preload the inner ring of one of the bearings
An annular ridge with a coil spring
An annular ridge is provided on the outer peripheral side of the boss of the impeller in the axial direction.
Bearing box provided in opposite directions and supporting the two bearings
An annular ridge on one end side of which the coil spring is interposed
And a ridge provided on the outer peripheral side of the boss.
To form a labyrinth structure urchin annular ridge is provided in the axial direction, further by mounting an end cap covering the end of the bearing housing, the other of said end cap is the two bearings
Support the outer ring of the other bearing and position it in the thrust direction.
Performs a fit, axial fan motor, characterized in that it has a sealed structure which covers the two bearings part and the labyrinth structure and the end cap.