JPH05256295A - Fan - Google Patents

Abstract

PURPOSE:To provide a fan easy to manufacture while providing vibration isolating performance similar to in the past by a small number of part items without generating vibration. CONSTITUTION:A ring-shaped opening part 7 is formed in a plate 2b of a fan hub 2. A plate side notched part 8 of communicating with the opening part 7 is formed from a plate side end part of a rib 6 to the vicinity of almost the center, in the rib 6 formed parallelly to a rotary shaft 4 between a boss 5 in a reverse surface side of the fan hub 2 and an internal peripheral surface 2d of a hub main unit 2a. Notched parts 9, 9 in the other end side are formed from an end part in a side mutually opposed to the plate 2b to the vicinity of almost the center so as to interpose this plate side notched part 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan, and more particularly to a fan having an improved vibration damping structure in a fan hub.

[0002]

2. Description of the Related Art A general fan is composed of a cylindrical fan hub and fan blades formed on the outer peripheral surface of the fan hub. Conventionally, in order to directly attach such a fan to a driving motor, the fan hub is actually opened.
A boss portion as shown in Japanese Patent Publication No. 79095 is formed.

FIG. 4 shows a conventional propeller fan, and FIG. 5 shows a boss portion thereof. The propeller fan 11 is constructed by integrally forming a fan hub 12 and a fan blade 13 with a resin material or the like. . And the fan hub 12
A boss portion 15 that is directly attached to a rotating shaft 14 of a motor (not shown) is provided at the center position of the.

The boss portion 15 has a shaft side metal boss 16 fitted with the rotating shaft 14, a rubber boss 17, and a boss side metal boss 18.
The rubber boss 17 absorbs rotationally excited vibration generated by torque unevenness in the rotation direction of the rotating shaft 14 (direction of arrow a), and the fan blade 13 generated by this vibration.
Also, the torsional vibration of the entire propeller fan 11 and the generation of noise are prevented.

Further, the boss side metal boss 18 is provided as a heat insulating layer for preventing the rubber boss 17 from being deformed by the high temperature resin material forming the fan hub 12 when the boss portion 15 is cast into the fan hub 12. In addition, fan hub 1
A plurality of ribs 19 for improving the strength of the fan hub 12 are formed between the boss portion 15 and the outer peripheral surface of the second back surface.

[0006]

However, the fan provided with such a conventional vibration isolation mechanism has the following problems.

1) The rubber boss for absorbing the vibration of the rotary shaft is flexible in all directions with respect to the rotary shaft, and when the fan is unbalanced, the radial direction (arrow b direction) and the vertical direction (arrow direction). Displacement occurs in the (c direction), and new vibration different from the rotationally excited vibration is generated. 2) Since the boss and fan hub are configured as separate parts,
It is difficult to align the shaft centers during molding, and high precision is required for assembly. 3) Since the boss part is made of metal, rubber, and metal, the number of parts is large and the manufacturing cost is high.
Molding time also becomes longer.

The present invention solves the above problems, does not generate vibration even when the fan is unbalanced, has the same vibration isolation performance as the conventional one with a small number of parts, and is easy to manufacture. Intended to provide fans.

[0009]

In order to solve the above-mentioned problems, the first invention of the present application closes a boss portion into which a rotary shaft is fitted, a hub body formed in a cylindrical shape, and one end of the hub body. In a fan in which a fan hub is formed of a plate, a plurality of fan blades are formed on the fan hub, and a plurality of ribs are provided between the boss portion and the inner peripheral surface of the hub body, a ring-shaped opening is formed in the plate. At least one plate-side notch communicating with the opening at the plate-side end of the rib, and at least one other-side notch at the end facing the plate. Then configured.

Further, according to the second aspect of the present invention, the reinforcing rib is integrally formed on the edge of the plate side notch formed in the rib.

[0011]

According to this structure, since the notch is provided on the plate side and the other end side, the rib itself acts as a spring in the rotating direction and is strong in the radial direction and the vertical direction. Until now, it is flexible only in the direction of rotation,
The rotation-induced vibration can be absorbed without using a separate part such as a rubber boss.

[0012]

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

In FIG. 1, a fan 1 is integrally formed with a fan hub 2 and a fan blade 3 by injection molding a synthetic resin material or the like. The fan hub 2 is a cylindrical hub body 2a and this hub. The fan blade 3 includes a plate 2b that closes one end of the opening of the main body 2a.
Are formed on the outer peripheral surface 2c of the hub body 2 at equal intervals.

In FIG. 2, a boss 5 to which a rotary shaft 4 of a motor (not shown) is directly attached is formed at a center position on the back surface side of the fan hub 2, and the boss 5 and the inner peripheral surface of the hub body 2 are formed. A plurality of ribs 6 are formed in parallel with the rotating shaft 4 between the 2d and 2d at equal intervals. The plate 2b of the fan hub 2 has a ring-shaped opening 7 concentric with the fan hub 2 at a position approximately half the radius of the fan hub 2. A plate-side cutout portion 8 that communicates with the opening 7 is formed in the rib 6 from the plate-side end portion of the rib 6 to approximately the center thereof. Further, the other-side cutouts 9 and 9 are formed so as to sandwich the plate-side cutout 8 from the end on the side facing the plate 2b to approximately the vicinity of the center.

Next, the operation will be described based on the above configuration.

The rib 6 is formed with the plate-side cutout portion 8 and the other end-side cutout portions 9 and 9, so that the boss 5 and the hub body 2 are formed.
The inner peripheral surface 2d of a is connected to each other via a U-shaped spring, is flexible in the rotation direction (direction of arrow a), and is radial (direction of arrow b) or vertical direction (direction of arrow b). It has some strength in the direction of arrow c).

Therefore, when the propeller fan 1 is rotated, since the rotation direction (direction of arrow a) is flexible, the rib 6 absorbs the rotation-induced vibration even if torque-induced vibration causes the vibration, and the propeller fan 1 is rotated. It is possible to prevent the generation of noise due to the torsional vibration of the.

Further, in the radial direction (arrow b direction) and the vertical direction (arrow c direction), since the ribs have the same strength as the conventional ribs, even if the fan is unbalanced, the displacement with respect to the rotating shaft is increased. Does not occur, and new vibration different from rotationally excited vibration is not generated.

Furthermore, unlike the conventional case, the boss 5 is not a separate part, so that all the constituent parts can be integrally formed by injection molding or the like, and high precision is not required for assembly. The number of parts is small, the manufacturing cost can be suppressed, and the molding time can be shortened.

FIG. 3 shows another embodiment, in which a plate side cutout 8 is formed.
The reinforcing ribs 10 are formed at the edges of the ribs 6, and the ribs 6 become stronger in the radial direction (the direction of the arrow b) and can be further prevented from being deformed in the radial direction.

In the present embodiment, the rib 6 is provided with one plate-side cutout 8 and two other-end-side cutouts 9. However, the present invention is not limited to this, and at least one rib 6 is provided for each rib 6. Has a function as a spring, so if each is reduced, it becomes a solid spring as to the rotation direction, and if each is increased, it becomes soft. further,
In order to change the performance as a spring, the width of the rib 6 and the width / thickness / length of the notches 8 and 9 may be changed.

In addition, although the propeller fan has been described in this embodiment, the present invention is not limited to this, and a fan provided with a fan hub having a boss portion such as an axial fan is effective.

[0023]

According to the present invention, a fan hub is composed of a boss portion into which a rotary shaft is fitted, a hub body formed in a cylindrical shape, and a plate closing one end of the hub body. In a fan having a blade and a plurality of ribs provided between the boss and the inner circumferential surface of the hub body, a ring-shaped opening is provided in the plate, and the plate-side end of the rib is provided with the above-mentioned opening. By forming at least one plate-side cutout communicating with the opening and forming at least one other-end cutout at the end opposite to the plate, rotationally excited vibration is suppressed as in the conventional case. It is also possible to generate a new vibration different from the rotation excitation vibration.

Since the boss is not a separate part, high precision is not required for assembly, the number of parts is small, the manufacturing cost can be suppressed, and the molding time can be shortened.

[Brief description of drawings]

FIG. 1 is a perspective view showing a fan according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA ′ in FIG.

FIG. 3 is an enlarged view of a main part of a rib according to another embodiment of the present invention.

FIG. 4 is a perspective view showing a conventional fan.

5 is a sectional view taken along line BB ′ in FIG.

[Explanation of symbols]

1 ... Fan, 2 ... Fan hub, 2a ... Hub body, 2b ...
Plate, 2c ... Outer peripheral surface, 2d ... Inner peripheral surface, 5 ... Boss, 4
... Rotary shaft, 6 ... Rib, 7 ... Opening, 8 ... Plate side notch, 9 ... Other end notch

Claims (2)

[Claims] 1. A fan hub is formed of a boss portion into which a rotary shaft is fitted, a hub body formed in a cylindrical shape, and a plate closing one end of the hub body, and a plurality of fan blades are formed on the fan hub. In a fan having a plurality of ribs provided between the boss portion and the inner peripheral surface of the hub body, a ring-shaped opening is provided in the plate, and a plate communicating with the opening is provided at a plate-side end of the rib. A fan characterized in that at least one side cutout is formed, and at least one other end cutout is formed at an end opposite to the plate. 2. The fan according to claim 1, wherein a reinforcing rib is integrally formed on an edge of the plate-side cutout portion.