JPH0713416Y2 - Axial fan motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is directed to an axial fan motor that cools electronic equipment such as OA equipment by sending air in the axial direction with a resin propeller type impeller. Regarding

[Summary of the Invention] In this invention, a rotor shaft is rotatably supported by a bearing of a stator, and a resin propeller-shaped impeller is fixed to a metal rotor yoke of the rotor, and the rotor yoke is rotated to rotate the rotor. In an axial fan motor configured to blow air in an axial direction with an impeller, an elastic part that is pressed against the shaft in one axial direction of the bearing is integrally formed on the shaft side of the impeller, thereby reducing the number of parts. Also, the number of assembling steps can be reduced, and the manufacturing cost can be further reduced accordingly.

[Prior Art] For example, an electronic device such as an OA device is provided with an axial fan motor that cools the electronic device by blowing air in an axial direction with a resin propeller impeller.
This will be specifically described with reference to FIG. 3. Reference numeral 1 denotes an axial fan motor (cylindrical brushless motor), which is an outer rotor type rotor 2 and a slot type stator 3 rotatably supporting the rotor 2. And an impeller 4 fixed to the rotor 2 and a square tubular mounting frame 5 with the stator 3 fixed in the center.

The rotor 2 has a cylindrical metal-made rotor yoke 11 having an opening at the lower end side, and a disk-shaped center hole 11a formed at the center of the upper portion of the rotor yoke 11, with the upper end portion press-fitted to vertically project downward. The shaft 12, the cylindrical rotor magnet 13 fixed to the inner peripheral surface of the rotor yoke 11, and the blade fixed to the outer peripheral surface of the rotor yoke 11 by being fitted to the outer peripheral surface of the rotor yoke 11 via a thermal caulking portion 14. It consists of a car 4.

The stator 3 includes a stator frame 20 having a cylindrical portion 20a protruding in the center, and a cylindrical portion of the stator frame 20.
A slot-shaped stator yoke 21 fitted and fixed by caulking to 20a, and a cylindrical center hole of this stator yoke 21.
A pair of bearings 22 and 23 fitted to the upper and lower ends of 21a and rotatably supporting the shaft 12 of the rotor 2, and wound around the stator yoke 21 via a laminated core 24,
A plurality of electronic components such as a drive coil 25 of, for example, a two-phase, four-slot, which faces the rotor magnet 13 with a fixed clearance, and a magnetic pole sensor 26 fixed to the upper portion of the stator frame 20 and facing the rotor magnet 13 are provided. It is composed of the provided substrate 27.

Further, the shaft 12 of the rotor 2 is provided between the lower part of the rotor yoke 11 on the shaft 12 side and the upper bearing 22 of the stator yoke 21.
There is interposed a leaf spring 6 press-formed into an inverted substantially conical shape that pierces the shaft 12 and presses the shaft 12 in one axial direction of the bearings 22, 23 of the stator 3. Further, the lower bearing 23 is
It is prevented from coming off by a substantially E-shaped stop ring 7 locked to 12. As a result, the leaf spring 6 is placed on the upper bearing 22.
It acts so as to elastically urge the inner side of the lower part of the bearing, and also acts to push up the lower bearing 23 in the opposite direction, giving a so-called preload to these upper and lower bearings 22, 23, and the axial fan When the motor 1 is driven, the play of the shaft 12 of the rotor 2 in the axial direction is prevented.

Further, the impeller 4 has a plurality of propeller-shaped blades (blades) 4a integrally formed on the outer side of its cylindrical body.
Further, the mounting frame 5 is made of aluminum alloy or the like, and its inner peripheral surface 5a is formed in a cylindrical shape. This inner surface
A stator frame 20 of the stator 3 is attached to a lower portion of the inner peripheral surface 5a so as to be positioned at the center of the inner peripheral surface 5a by a plurality of radially extending stays 8.

When a current is passed through the drive coil 25 of the stator 3 to excite the coil 25, the rotor yoke 13 and the impeller 4 rotate the shaft 12 because a torque is generated due to the excitation of the rotor magnet 13 of the rotor 2. By rotating in a predetermined direction around the center, the wind can be sent out in the direction of the arrow (downward) in the figure.

[Problems to be Solved by the Invention] However, in the conventional axial fan motor 1, the shaft 12 of the rotor 2 is connected to the bearings 22 and 23 of the stator 3 in order to prevent the rotor 2 from rattling in the axial direction. Since it is necessary to separately provide an elastic member such as a leaf spring 6 that applies a so-called preload that is constantly pressed in one direction of the bearing, there is a disadvantage that the number of partial points and the assembling process increase by that amount and the cost increases.

Therefore, the present invention provides an axial fan motor that can reduce the number of parts and reduce the cost.

[Means for Solving the Problems] A rotor shaft is rotatably supported by a bearing of a stator, while a resin propeller-shaped impeller is fixed to a metal rotor yoke of the rotor, and the rotor yoke is rotated to rotate the rotor. In an axial flow fan motor in which the impeller is capable of sending air in the axial direction, a large-diameter center hole is formed in the center of the rotor yoke, and an inverted conical portion is projected from the center hole to the center of the bottom of the impeller. The shaft is hung at the center of the inverted conical portion, and an elastic portion for pressing the shaft in one axial direction of the bearing is integrally formed on the lower side of the inverted conical portion.

[Operation] Since the elastic portion for pressing the shaft in the axial direction of the stator bearing is integrally formed on the shaft side of the impeller to which the rotor yoke is fixed, the rotor shaft is aligned in the bearing direction of the stator bearing as in the conventional case. Since it is not necessary to separately provide an elastic member such as a leaf spring to be pressed, the number of parts and the number of assembling steps can be reduced, and the cost can be reduced.

[Embodiment] An embodiment of the present invention will be described in detail below with reference to the drawings. still,
The same parts as those of the conventional configuration are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, reference numeral 1 is an axial fan motor, and a rotor 2 and a stator 3 for rotatably supporting the rotor 2 and an impeller 4 fixed to the rotor 2 are provided for the axial fan motor 1.
And a rectangular tubular mounting frame 5 with the stator 3 fixed in the center
And the rotor yoke 11
The stator 3 includes a stator frame 20, a stator yoke 21, a pair of bearings 22 and 23, a drive coil 25, and a substrate 27.
The configuration and the like are similar to the conventional configuration.

Here, the center hole 11a of the rotor yoke 11 is formed to have a large diameter, and the center of the bottom of the impeller 4 projects in an inverted conical shape from the center hole 11a.
The upper end of the shaft 12 is so-called insert-molded by heat welding or the like and hangs down at the center of the shaft. An elastic portion 9 for pressing the shaft 12 in one axial direction of the pair of bearings 22, 23 is integrally formed on the lower side of the inverted conical portion 4b. As shown in FIG. 2, the elastic portion 9 has four body portions 9a protruding radially with a shaft 12 as a center, and extends horizontally at the tip of each body portion 9a, and the upper bearing 22 It comprises a tip portion 9b for pressing and urging the inside of the body, and a cavity portion 9c formed above each of the body portions 9a. The impeller 4 is integrally formed of plastic such as saturated polyester (PBT: polybutylene terephthalate).

According to the axial fan motor 1 of the above embodiment, the elastic portion that presses the shaft 12 of the impeller 4 fixed to the rotor yoke 11 in one axial direction of the bearings 22 and 23 of the stator 3. 9
Since it is integrally molded with plastic such as saturated polyester, the shaft 12 of the rotor 2 is fixed to the stator 3 as in the conventional case.
Leaf springs 6 pressed in one direction of bearings 22 and 23
Since it is not necessary to separately provide such an elastic member, it is possible to reduce the number of parts and the assembling process correspondingly, and it is possible to further reduce the cost of manufacturing the motor.

In addition, according to the above-mentioned embodiment, the motor using the outer rotor has been described, but it goes without saying that the invention can be applied to the motor using the flat rotor having the thin coil on the stator side.

As described above, according to the present invention, a large-diameter center hole is formed in the center of the rotor yoke, and an inverted conical portion is formed in the center of the bottom of the impeller fixed to the rotor yoke. Since the shaft is made to project and the shaft is hung in the center of the inverted conical portion, and the elastic portion for pressing the shaft in the axial direction of the bearing of the stator is integrally formed on the lower side of the inverted conical portion. Since it is not necessary to separately provide an elastic member such as a leaf spring for pressing the rotor shaft in the bearing direction of the stator bearing, the number of parts and the assembly process can be reduced accordingly, and the cost can be further reduced. .

[Brief description of drawings]

FIG. 1 is a sectional view of an axial flow fan motor showing an embodiment of the present invention, FIG. 2 is a bottom view of an essential part of the motor, and FIG. 3 is a sectional view of a conventional axial flow fan motor. 1 ... Axial fan motor, 2 ... Rotor, 3 ... Stator, 4
... impeller, 4b ... inverted conical part, 9 ... elastic part, 11 ... rotor yoke, 11a ... center hole, 12 ... shaft, 22, 23 ... bearing.

Claims (1)

[Scope of utility model registration request] 1. A rotor shaft is rotatably supported by a bearing of a stator, while a resin propeller-shaped impeller is fixed to a metallic rotor yoke of the rotor, and rotation of the rotor yoke causes wind on the impeller. In the axial fan motor that can freely send out in the axial direction, a large-diameter center hole is formed in the center of the rotor yoke,
An inverted conical portion is projected from the center hole to the center of the bottom of the impeller, the shaft is hung at the center of the inverted conical portion, and the shaft is provided on the lower side of the inverted conical portion of the bearing. An axial fan motor characterized by integrally molding an elastic portion that is pressed in one axial direction.