Axial flow fan

Abstract

To provide an axial flow fan which can suppress a rise of a temperature of an internal component even at high-loading without lowering the performance of the fan.SOLUTION: An axial flow fan for blowing air to a blowing direction W comprises: a rotor blade 4 rotating around a rotation axial line X which extends along the blowing direction W; a cylindrical base part 6 located on the rotation axial line X at a downstream side of the rotor blade 4 in the blowing direction W; and an outer frame part 2 in which the rotor blade 4 and the base part 6 are accommodated. The base part 6 has an inclination part 62 which is contracted in a diameter toward the downstream side of the blowing direction W at its end part at the downstream side in the blowing direction W. An opening part 71 which is formed with a prescribed interval in a peripheral direction, and a hollow rib 72 progressing toward the downstream side of the blowing direction W so as to surround a peripheral part of the outside of the opening part 71 in a radial direction, and extending so as to protrude from the inclination part 62 along the rotation axial line X are formed at the inclination part 62.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an axial fan. [Background technology]

[0002] A fan configured to suppress a temperature rise of electronic components on a circuit board arranged in a stator frame is known from Patent Document 1 and the like. According to the fan of Patent Document 1, a first axial through hole is formed on the radial inside of the bottom of the stator frame, and a second axial through hole is formed on the radial outside, and air that flows into the inside of the stator frame from the first axial through hole flows along the surface of the circuit board and flows out to the outside from the second axial through hole, thereby cooling the electronic components. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-210700 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the case of the fan disclosed in Patent Document 1, although it is possible to cool electronic components by circulating air inside the stator frame via the first axial through hole and the second axial through hole, no consideration is given to the fact that the static pressure performance of the fan is reduced by forming the first axial through hole and the second axial through hole at the bottom of the stator frame.

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide an axial fan that is capable of suppressing a rise in temperature of internal components even under high load without degrading fan performance. [Means for solving the problem]

[0006] An axial flow fan according to one aspect of the present invention includes: An axial flow fan that blows air in a blowing direction, A rotor blade that rotates around a rotation axis extending along the air blowing direction; a cylindrical base portion located on the rotation axis line and downstream of the rotor blade in the air blowing direction; an outer frame portion in which the rotor blade and the base portion are housed; Equipped with The base portion is a downstream end portion in the air blowing direction has an inclined portion whose diameter decreases toward the downstream side in the air blowing direction, The inclined portion has Openings provided at predetermined intervals in the circumferential direction; A hollow rib is provided which extends so as to surround the outer periphery of the opening in the radial direction and protrude from the inclined portion along the rotation axis toward the downstream side in the air blowing direction. Effect of the Invention

[0007] According to the present invention, it is possible to provide an axial fan that is capable of suppressing a rise in temperature of internal components even under high load without degrading fan performance. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view of an axial flow fan according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of the axial flow fan shown in FIG. [Diagram 3] FIG. 2 is a front view of the axial flow fan shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. For the sake of convenience, the description of the components having the same reference numbers as those already described in the description of the embodiment will be omitted. Also, for the sake of convenience, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component.

[0010] Fig. 1 is a perspective view of an axial flow fan 1 according to a preferred embodiment of the present invention. Fig. 2 is a cross-sectional view of the axial flow fan 1 shown in Fig. 1 taken along the air blowing direction W. 1 and 2, the axial flow fan 1 includes an outer frame 2, and rotor blades 4 and a base 6 housed within the outer frame 2. Within the outer frame 2, the rotor blades 4 are disposed upstream of the air blowing direction W, and the base 6 is disposed downstream.

[0011] The outer frame 2 forms a cylindrical wind tunnel space 23 that communicates with a wind (air) suction inlet 21 and a wind outlet 22. The rotor blades 4 and the base 6 are housed in the wind tunnel space 23. Wind sucked in from the suction inlet 21 as the rotor blades 4 rotates is sent along the wind tunnel space 23 in a blowing direction W, and is sent out from the wind outlet 22 to the outside.

[0012] The rotor blades 4 are attached to the outer peripheral surface of the rotor blade case 41. The rotor blade case 41 is formed in a cup shape. A plurality of the rotor blades 4 (five in the illustrated example) are attached at equal intervals around the circumference of the rotor blade case 41. The rotor blade case 41 is arranged with its opening facing the downstream side of the air blowing direction W. A bottom wall 42 of the rotor blade case 41 located on the upstream side of the air blowing direction W is provided with an opening 43 through which outside air can flow into the rotor blade case 41.

[0013] A motor 51 is housed in the rotor blade case 41. The motor 51 is composed of a rotating shaft 52, a rotor 53 having a permanent magnet, and a stator 54 around which a winding is wound. The rotor blade case 41 is fixed to the rotating shaft 52 of the motor 51. The permanent magnets of the rotor 53 are fixed to the inner circumferential surface of the rotor blade case 41. The rotor blades 4 attached to the rotor blade case 41 rotate around the rotation axis X as the rotating shaft 52 rotates.

[0014] The base portion 6 is formed in a cylindrical shape, and is disposed with its opening facing upstream in the air blowing direction W. The base portion 6 is also disposed in the center in the radial direction of the air tunnel space 23 of the outer frame portion 2 so as to be aligned with the rotation axis X. The base portion 6 is disposed so as to face its opening to the opening of the rotor blade case 41 and close the opening of the rotor blade case 41.

[0015] The base portion 6 has a cylindrical portion 61 and an inclined portion 62 continuous with the cylindrical portion 61. The cylindrical portion 61 is provided on the upstream side of the air blowing direction W, and is formed into a cylindrical shape with a constant diameter. The inclined portion 62 is provided on the downstream side of the air blowing direction W, and is tapered so that the diameter decreases toward the downstream side of the air blowing direction W, i.e., toward the air outlet 22 of the outer frame portion 2.

[0016] A downstream portion of the motor 51 in the air blowing direction W is housed within the base portion 6. A stator 54 of the motor 51 is fixed to the base portion 6. A circuit board 55 on which electronic components for controlling the operation of the axial fan 1 are mounted is also housed within the base portion 6. The circuit board 55 is fixed to the stator 54 of the motor 51. The circuit board 55 is fixed with the board surface on which the electronic components are mounted facing the downstream and upstream sides of the air blowing direction W.

[0017] The base portion 6 is fixed to the outer frame portion 2 via the fixed blades 63. The fixed blades 63 are stator blades for connecting the base portion 6 to the outer frame portion 2. In the illustrated example, seven fixed blades 63 are provided. The seven fixed blades 63 are provided at equal intervals in the circumferential direction. The fixed blades 63 connect the base portion 6 to the outer frame portion 2, thereby fixing the base portion 6 to the radial center of the wind tunnel space 23.

[0018] The fixed blades 63 are provided between the inner peripheral surface of the outer frame portion 2 and the outer peripheral surface of the base portion 6. The radially outer ends of the fixed blades 63 are connected to the inner peripheral surface of the outer frame portion 2. The radially inner ends of the fixed blades 63 are connected to the outer peripheral surface of the cylindrical portion 61 of the base portion 6. The fixed blades 63 are provided in the wind tunnel space 23, downstream of the rotor blades 4 in the air blowing direction W.

[0019] A plurality of openings 71 are provided in the inclined portion 62 of the base portion 6. The openings 71 are provided at predetermined intervals in the circumferential direction of the inclined portion 62. In the illustrated example, six openings 71 are provided so as to correspond to the fixed blades 63 in the circumferential direction.

[0020] A hollow rib 72 is provided around the periphery of the opening 71, extending so as to protrude from the inclined portion 62. The hollow rib 72 is provided so as to surround the radially outer side of the periphery of the opening 71, i.e., the side closer to the air tunnel space 23. The hollow rib 72 protrudes from the inclined portion 62 and is provided along the rotation axis X toward the downstream side in the air blowing direction W.

[0021] The hollow rib 72 is formed, for example, in an arc shape as a peripheral wall surrounding the outside of the periphery of the opening 71. The hollow rib 72 is formed as a peripheral wall that separates the opening 71 from the wind flowing in the wind tunnel space 23 in the blowing direction W. The hollow rib 72 functions as a peripheral wall that prevents the wind flowing in the wind tunnel space 23 in the blowing direction W from flowing radially inward toward the opening 71. By providing the hollow rib 72 on the inclined portion 62, it becomes possible to allow air to flow from the outside into the base portion 6 through the opening 71 without affecting the flow of the wind flowing in the wind tunnel space 23 in the blowing direction W. The air that has flowed into the base portion 6 is sucked out into the wind tunnel space 23 from the gap 56 between the base portion 6 and the rotor blade case 41 that are arranged opposite to each other.

[0022] The opening 71 and the hollow rib 72 are provided at a position spaced away from the end face 64 of the base part 6 on the downstream side in the air blowing direction W toward the upstream side of the air blowing direction W. In other words, the opening 71 and the hollow rib 72 of the base part 6 are provided at a position recessed from the end face 64 of the base part 6 toward the upstream side of the air blowing direction W.

[0023] A protrusion 73 is provided inside the opening 71, extending radially inward from the outer circumferential wall of the base portion 6. The outer circumferential wall of the base portion 6 may be the outer circumferential wall of the cylindrical portion 61 in the base portion 6, or may be the outer circumferential wall of the inclined portion 62 in the base portion 6. In the illustrated example, the protrusion 73 extends from the outer circumferential wall of the inclined portion 62. The opening 71 is formed as an opening that constitutes a labyrinth structure by providing the protrusion 73 inside. This allows air to flow in while suppressing the inflow of dust from the outside into the base portion 6 through the opening 71.

[0024] Fig. 3 is a front view of the axial flow fan 1. The positional relationship between the openings 71 and the hollow ribs 72 and the fixed blades 63 will be described with reference to Fig. 3.

[0025] 3, the fixed blades 63 are thin plate-like members provided radially on the outer periphery of the base portion 6. In the illustrated example, the fixed blades 63 are attached between the outer frame portion 2 and the base portion 6 with the fixed blade direction B being inclined at a predetermined angle θ with respect to the radial direction R.

[0026] The openings 71 and hollow ribs 72 are provided so as to be included in a circumferential range C in which the inclined fixed blades 63 exist in the circumferential direction of the base portion 6 when viewed in the direction of the rotation axis X, for example, from the front side of the axial fan 1. In other words, the openings 71 and hollow ribs 72 are disposed downstream of the fixed blades 63 so as to overlap with the fixed blades 63 in the airflow direction W, and are provided so as to be shielded by the fixed blades 63 from the wind flowing through the air tunnel space 23 in the airflow direction W. The angle θ of the inclined fixed blades 63 may differ depending on the axial fan.

[0027] As described above, the axial fan 1 of this embodiment includes the rotor blades 4 that rotate around the rotation axis X that extends along the airflow direction W, the cylindrical base portion 6 that is located on the rotation axis X downstream of the rotor blades 4 in the airflow direction W, and the outer frame portion 2 that houses the rotor blades 4 and the base portion 6. The base portion 6 has an inclined portion 62 at an end downstream in the airflow direction W, the inclined portion 62 having a diameter that decreases toward the downstream side of the airflow direction W. The inclined portion 62 is provided with openings 71 that are provided at predetermined intervals in the circumferential direction, and hollow ribs 72 that extend to surround the outer periphery of the openings 71 in the radial direction and protrude from the inclined portion 62 along the rotation axis X toward the downstream side of the airflow direction W. By providing the openings 71 and the hollow ribs 72 that surround the periphery of the openings 71 in the inclined portion 62 of the base portion 6 in this way, the openings 71 can be shielded from the wind flowing in the airflow direction W through the wind tunnel space 23. This makes it possible to suppress a decrease in the air volume and static pressure performance of the axial fan 1 that may occur when the opening 71 is provided in the base 6. Also, air can flow into the base 6 from the outside through the opening 71 without affecting the wind flowing through the air tunnel space 23. Therefore, for example, when the axial fan 1 is under high load, the air that has flowed into the base 6 can be configured to hit the circuit board 55, thereby suppressing a rise in temperature of electronic components, etc. This makes it possible to suppress the amount of heat generated inside the axial fan 1.

[0028] Furthermore, in the axial flow fan 1, the hollow rib 72 is formed in an arc shape that surrounds the outer periphery of the opening 71 in the radial direction. By forming the hollow rib 72 in an arc shape in this manner, the opening 71 can be blocked without affecting the wind flowing through the air duct space 23, and a decrease in the air volume and static pressure performance of the axial flow fan 1 can be suppressed.

[0029] Furthermore, in the axial flow fan 1, the openings 71 and the hollow ribs 72 are located at a distance from the downstream end face of the base 6 in the air blowing direction W to the upstream side of the air blowing direction W. In this way, by locating the openings 71 and the hollow ribs 72 at a distance from the downstream end face of the base 6, air can be smoothly introduced into the base 6 from the outside through the openings 71, and deterioration in air volume and static pressure performance can be further suppressed.

[0030] Moreover, in the axial flow fan 1, the opening 71 has a labyrinth structure in which protrusions 73 extending radially inward from the outer circumferential wall of the base 6 are provided within the opening 71. By providing the inside of the opening 71 with this labyrinth structure, it is possible to prevent dust from entering the base 6 from the opening 71.

[0031] The axial fan 1 further includes fixed blades 63 that are provided between the inner circumferential surface of the outer frame 2 and the outer circumferential surface of the base 6 and downstream of the rotor blades 4 in the airflow direction W. The openings 71 and hollow ribs 72 are provided downstream of the fixed blades 63 in the airflow direction W and are provided so as to be included in a circumferential range C in which the fixed blades 63 are provided in the circumferential direction when viewed from the direction of the rotation axis X. By providing the openings 71 and hollow ribs 72 so as to overlap with the fixed blades 63 downstream of the fixed blades 63 in the airflow direction W when viewed from the direction of the rotation axis X, it is possible to reduce the effect on the air flowing through the wind tunnel space 23 and further suppress the deterioration of the air volume and static pressure performance.

[0032] Although the embodiment of the present invention has been described above, it goes without saying that the technical scope of the present invention should not be interpreted as being limited by the description of the embodiment. The embodiment is merely an example, and it is understood by those skilled in the art that various modifications of the embodiment are possible within the scope of the invention described in the claims. The technical scope of the present invention should be determined based on the scope of the invention described in the claims and its equivalents. [Explanation of symbols]

[0033] 1 Axial Fan 2 Outer frame 4 Moving blades 6 Base 23 Wind tunnel space 41 Blade case 51 Motor 52 Rotation axis 53 Rotor 54 Stator 55 Circuit Board 61 Cylindrical part 62 Slope 63 Fixed Blade 71 Opening 72 Hollow Rib 73 Protrusion C Circumferential range W Airflow direction X rotation axis

Claims

1. An axial flow fan that blows air in a blowing direction, A rotor blade that rotates around a rotation axis extending along the air blowing direction; a cylindrical base portion located on the rotation axis line and downstream of the rotor blade in the air blowing direction; an outer frame portion in which the rotor blade and the base portion are housed; Equipped with The base portion is a downstream end portion in the air blowing direction has an inclined portion whose diameter decreases toward the downstream side in the air blowing direction, The inclined portion has Openings provided at predetermined intervals in the circumferential direction; A hollow rib is provided so as to extend from the inclined portion along the rotation axis toward the downstream side in the air blowing direction so as to surround an outer periphery of the opening in the radial direction. Axial fan.

2. The opening and the hollow rib are provided at a position spaced from a downstream end face of the base portion in the air blowing direction to an upstream side in the air blowing direction. The axial fan according to claim 1 .

3. a fixed blade provided between an inner circumferential surface of the outer frame portion and an outer circumferential surface of the base portion and downstream of the rotor blade in the air blowing direction, the opening and the hollow rib are provided downstream of the fixed blade in the air blowing direction, and are provided so as to be included within a circumferential range in which the fixed blade is provided in the circumferential direction when viewed from the direction of the rotation axis.

3. An axial fan according to claim 1 or 2.

4. The hollow rib is formed in an arc shape surrounding the outer periphery of the opening. The axial fan according to any one of claims 1 to 3.

5. The opening has a labyrinth structure in which a protrusion extending from an outer circumferential wall of the base portion toward an inner side in the radial direction is provided within the opening. The axial fan according to any one of claims 1 to 4.

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