Axial flow fan

Abstract

To provide an axial flow blower that prevents wear.SOLUTION: An axial flow blower 100 comprises a pair of fan units 1. The respective fan units 10 and 30 comprise: rotors comprising impeller cups to be rotated around a rotation axis L, and fans 15 and 35 extending in a radial direction from the impeller cups; motors provided inside the impeller cups; and housings comprising housing parts housing the rotors, and base parts supporting the motors. Connection parts are provided closer to an inner peripheral side than the impeller cups and in axial end surfaces of the respective base parts. The respective fan units 10 and 30 are mutually connected in the direction of the rotation axis L via the mutual connection parts.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] 2. Description of the Related Art Axial flow fans are known that increase the air volume by connecting a pair of fan units in series.

[0003] For example, in the axial flow fan of Patent Document 1, a male screw is provided on the outer periphery of the front fan unit of a pair of fan units, and a female screw is provided on the outer periphery of the rear fan unit, and the pair of fan units are connected in series by fastening the male screw and the female screw together. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-28491 Summary of the Invention [Problem to be solved by the invention]

[0005] In the fan unit of Patent Document 1, the bushings and housing base that support the rotating shaft and bearings are located in the radial center. Therefore, when a pair of fan units are connected to form a counter-rotating fan, the bushings are arranged to contact each other at the center of the fan unit. Because the bushings are not directly connected to each other, there is a risk that the metal bushings will rub against each other due to fan vibration, generating wear powder.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an axial flow fan that is prevented from wearing. [Means for solving the problem]

[0007] An axial flow fan according to one aspect of the present invention comprises: An axial flow fan having a pair of fan units, Each of the fan units comprises: a rotor having an impeller cup that rotates about a rotation axis and a fan that extends radially from the impeller cup; a motor provided inside the impeller cup; a housing having an accommodating portion that accommodates the rotor and a base portion that supports the motor; Equipped with A connecting portion is provided on the axial end surface of each of the base portions, located more inward than the impeller cup, and each of the fan units is connected to each other in the direction of the rotation axis via each of the connecting portions. [Effects of the Invention]

[0008] According to the present invention, it is possible to prevent the generation of wear powder caused by rubbing of the connecting portions against each other due to vibration of the fan. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of an axial flow fan according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional perspective view of AA in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 4] FIG. 2 is a cross-sectional view of BB in FIG. [Figure 5] 1 is a perspective view of a pair of housings according to a first embodiment of the present invention. [Figure 6] FIG. 10 is a perspective view of a pair of housings according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a perspective view of a pair of housings according to a third embodiment of the present invention. [Figure 8] FIG. 10 is a perspective view of a conventional axial flow fan. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. For the sake of convenience, the description of components having the same reference numerals as those already described in the description of the embodiments will be omitted. Furthermore, for the sake of convenience, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component. [First embodiment]

[0011] FIG. 1 is a perspective view showing an example of an axial flow fan according to a first embodiment of the present invention. As shown in Fig. 1, the axial flow fan 100 has a pair of fan units 1. The pair of fan units 1 is configured by connecting a front fan unit 10 and a rear fan unit 30 in series. The fans of the fan units 10, 30 share a common rotation axis L.

[0012] The axial flow fan 100 is a counter-rotating fan in which the fan 15 of the front-stage fan unit 10 and the fan 35 of the rear-stage fan unit 30 rotate in different directions. Air is drawn in by the fan 15 of the front-stage fan unit 10, and the drawn-in air is expelled by the fan 35 of the rear-stage fan unit 30. Note that although the axial flow fan 100 according to this embodiment is a counter-rotating fan in which the fans rotate in different directions, it may also be configured such that the fans rotate in the same direction and are connected in series.

[0013] Fig. 2 is a cross-sectional perspective view taken along line AA in Fig. 1. Fig. 3 is a cross-sectional view taken along line AA in Fig. 1. For the sake of explanation, Fig. 3 shows the configuration of axial flow fan 100 before fan units 10 and 30 are connected. 2 and 3, the fan unit 10 includes a rotor 11, a motor 12, and a resin housing 13. The rotor 11 has an impeller cup 14 that rotates about a rotation axis L, and a fan 15 that extends radially from the impeller cup 14. The motor 12 is provided inside the impeller cup 14. The housing 13 has an accommodating portion 16 that accommodates the rotor 11, and a base portion 17 that supports the motor 12. Similarly, the fan unit 30 includes a rotor 31, a motor 32, and a resin housing 33. The rotor 31 has an impeller cup 34 that rotates about a rotation axis L, and a fan 35 that extends radially from the impeller cup 34. The motor 32 is provided inside the impeller cup 34. The housing 33 has an accommodating portion 36 that accommodates the rotor 31, and a base portion 37 that supports the motor 32. The fan unit 30 has a similar configuration to the fan unit 10. Therefore, in the following description, the same reference numerals are used for the various portions of the fan unit 30, and a detailed description of the fan unit 30 will be omitted, and only the details of the fan unit 10 will be described.

[0014] The impeller cup 14 is a cup-shaped member that opens on one side in the axial direction. The motor 12 is provided inside the impeller cup 14. The impeller cup 14 is connected to a rotor of the motor 12. The motor 12 rotates the fan 15 fixed to the impeller cup 14.

[0015] Fig. 4 is a cross-sectional view taken along line BB perpendicular to the rotation axis L in Fig. 1. As shown in Figs. 3 and 4, the housing 13 has a cylindrical accommodating portion 16 extending in the direction of the rotation axis L, a disk-shaped base portion 17 located at an opening on one side in the axial direction of the accommodating portion 16, and a plurality of spokes 22 connecting the accommodating portion 16 and the base portion 17. The rotor 11 is rotatably housed inside the cylindrical housing portion 16 .

[0016] The base portion 17 has a disk shape extending in a direction perpendicular to the rotation axis L. A circuit board that drives the stator and mover of the motor 12 is fixed to the base portion 17. When viewed from the direction of the rotation axis L, the base portion 17 has the same size and shape as the impeller cup 14. This prevents the airflow generated by the fan 15 extending radially from the impeller cup 14 from being blocked by the base portion 17.

[0017] When viewed from the direction of the rotation axis L, the base portion 17 is disposed apart from the housing portion 16. Spoke portions 22 are provided in the space between the base portion 17 and the housing portion 16. The spoke portions 22 extend radially from the base portion 17 and connect the base portion 17 and the housing portion 16. Note that the spoke portions 22 do not simply connect the base portion 17 and the housing portion 16, but may also be configured as stator vanes that rectify the airflow generated by the fan 15.

[0018] In the fan unit 10 of this embodiment, a connection portion 18 is provided on the axial end face 17E of the base portion 17, which is located more inward than the impeller cup 14. In the example shown, the connection portion 18 is configured as a screw fastening portion. Similarly, in the fan unit 30, a connection portion 38 is provided on the axial end face 37E of the base portion 37, which is located more inward than the impeller cup 34. The axial end face 17E and the axial end face 37E face each other. The front-stage fan unit 10 and the rear-stage fan unit 30 are connected to each other in the direction of the rotation axis L via connecting portions 18, 38.

[0019] In the illustrated example, the fan unit 10 has a bearing 19 that rotatably supports the rotor 11 relative to the base portion 17. An inner ring member of this bearing 19 is fixed to the rotor 11. An outer ring member of the bearing 19 is fixed to a bushing 20 provided on the base portion 17. In other words, the base portion 17 has the bushing 20 that supports the bearing 19.

[0020] The bushing 20 is made of a metal such as aluminum or brass, and is insert-molded into the center of the base portion 17. The bushing 20 is a cylindrical member. The bearing 19 is press-fitted into the inner circumferential surface of the bushing 20. More specifically, a small-diameter portion is provided in the center of the inner circumferential surface of the bushing 20 in the direction of the rotation axis L, and large-diameter portions whose inner diameter is larger than that of the small-diameter portion are provided at both ends in the direction of the rotation axis L. The bearing 19 is press-fitted from this large-diameter portion toward the center in the direction of the rotation axis L, and the position of the bearing 19 in the direction of the rotation axis L is determined by the bearing 19 abutting against the small-diameter portion.

[0021] A connecting portion 18 is provided on an axial end surface 17E of the base portion 17. In the illustrated example, the connecting portion 18 is a cylindrical portion extending in the direction of the rotation axis L. A female thread is provided on the inner peripheral surface of the cylindrical connecting portion 18. The bushing 20 and the connecting portion 18 are configured as an integrated metal member.

[0022] On the other hand, the base portion 37 of the fan unit 30 has a cylindrical bushing 40. A connecting portion 38 is provided on an axial end face 37E of the base portion 17. The connecting portion 38 has a cylindrical shape extending in the direction of the rotation axis L. The outer peripheral surface of this cylindrical connecting portion 38 is provided with a male thread that engages with the female thread of the connecting portion 18. The inner diameter of the inner peripheral surface of the connecting portion 38 is larger than the outer diameter of the bearing 39 so that the press-fitted bearing 39 can be inserted therethrough.

[0023] According to the axial flow blower 100 of this embodiment, connection portions 18, 38 are provided on the axial end faces 17E, 37E of each base portion 17, 37, which are located more inward than the impeller cups 14, 34, and each fan unit 10, 30 is connected to each other in the direction of the rotation axis L via each other's connection portions 18, 38. That is, unlike the axial flow fan of Patent Document 1, in the axial flow fan 100 according to this embodiment, the fan units 10, 30 are connected by the connecting parts 18, 38 provided on the inner periphery side. Therefore, even if the fan units 10, 30 vibrate, the metal bushings 20, 40 located on the inner periphery side can be prevented from rubbing against each other, and the generation of wear powder can be suppressed. In the above-described embodiment, the housings 13 and 33 are made of resin, and the bushings 20 and 40 are made of metal. By making the housings 13 and 33 out of lightweight resin and the bushings 20 and 40 out of metal, which require strength, it is possible to achieve a strong connection structure while reducing the weight of the entire axial flow fan 100.

[0024] Furthermore, as described above, providing the connection parts 18 and 38 on the inner peripheral side makes it easier to handle the lead wires. This effect will be explained using Figures 4 and 8. Figure 8 is a perspective view of a conventional axial flow fan. 8, male threads 202 and female threads 203 (corresponding to connection parts) are provided on the outer periphery of the housing part. Therefore, these male threads 202 and female threads 203 are located in the space on the outer periphery of the housing part, which can interfere with routing of the lead wires drawn out from the housing part to the outer periphery. In contrast, in the axial flow fan 100 according to this embodiment, the connection portions 18, 38 are provided on the inner peripheral side, so the area occupied by the connection portions in the conventional example shown in Fig. 8 can be used for other purposes. Therefore, in the axial flow fan 100 according to this embodiment, as shown in Fig. 4, an outlet space S for lead wires (not shown) connected to the motor is open on the outer peripheral side of the accommodating portion 16 of the housing 13. In other words, no other members exist in the outlet space S, which is the area radially outside the accommodating portion 16. Therefore, this outlet space S can be used freely to arrange the lead wires.

[0025] In the above-described embodiment, a positioning portion for determining the circumferential positions of the fan units 10 and 30 may be provided. FIG. 5 is a perspective view of a pair of housings 13, 33 according to the first embodiment of the present invention. A plurality of positioning portions 21, 41 are provided on the axial end surfaces 17E, 37E of the base portions 17, 37 of the housings 13, 33. The positioning portions 21 are positioning grooves, and the positioning portions 41 are positioning claws. The positioning grooves and positioning claws are shaped to accommodate threaded engagement so that they are guided relative to one another along the rotational direction of the male thread of the connecting portion 38. This makes it easy to position the pair of housings 13, 33 when connecting the front-stage fan unit 10 and the rear-stage fan unit 30. [Second embodiment]

[0026] In the above-described embodiment, an example has been described in which the pair of connecting portions 18, 38 are connected to each other by screw fitting, but the present invention is not limited to this. FIG. 6 is a perspective view of a pair of housings 13, 33 according to the second embodiment of the present invention. The difference from the first embodiment of the present invention is that the connecting portions 18, 38 are connected by press-fitting rather than by threaded fitting. The connecting portion 18 has a cylindrical recess, and the connecting portion 38 has a ring-shaped protrusion. The inner diameter of the inner circumferential surface of the recess is larger than the outer diameter of the protrusion to allow the press-fitted protrusion to pass through. Furthermore, the multiple positioning portions 21, 41 are shaped to accommodate press-fitting so as to be guided along the direction of the rotation axis L. This makes it easier to assemble (connect) the axial flow fan 100. [Third embodiment]

[0027] Furthermore, in the above-described embodiment, the connecting portions 18, 38 are provided at the center portions of the axial end faces 17E, 37E of the base portions 17, 37, but the present invention is not limited to this. FIG. 7 is a perspective view of a pair of housings 13, 33 according to a third embodiment of the present invention. This embodiment differs from the first embodiment described above in that the connecting portions 18, 38 are provided not only at the central portions of the axial end faces 17E, 37E of the base portions 17, 37 but also over the entire axial end faces 17E, 37E. This makes it possible to ensure a sufficient fitting area for the connecting portions 18, 38, and firmly connect the connecting portions 18, 38 to each other. Furthermore, this embodiment differs from the first embodiment of the present invention in that the housings 13, 33 and the bushes 20, 40 are not made of resin or metal, but are integrally molded from metal such as aluminum. This improves the strength and heat dissipation performance of the entire axial flow fan.

[0028] Although the embodiments of the present invention have been described above, it goes without saying that the technical scope of the present invention should not be construed as being limited by the description of the present embodiments. The present embodiments are merely examples, and it will be understood by those skilled in the art that various modifications of the embodiments 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]

[0029] 1 pair of fan units 10 Front stage fan unit 30 Rear fan unit 11, 31 rotors 12, 32 motor 13, 33 Housing 14, 34 Impeller cup 15, 35 fans 16, 36 storage section 17, 37 Base 17E, 37E Axial end face 18, 38 Connection 19, 39 Bearings 20, 40 Bush 21, 41 Positioning part 22, 42 spokes 100, 200 axial blower 201 Pair of fan units 202 Male thread 203 Internal thread 210 Front fan unit 230 Rear fan unit L rotation axis S Drawer space

Claims

1. An axial flow fan having a pair of fan units, Each of the fan units comprises: a rotor having an impeller cup that rotates about a rotation axis and a fan that extends radially from the impeller cup; a motor provided inside the impeller cup; a housing having an accommodating portion that accommodates the rotor and a base portion that supports the motor; a bearing that rotatably supports the rotor relative to the base portion; Equipped with Each of the base portions has a bushing that supports the bearing; a connecting portion is provided on an axial end surface of the bush of each of the base portions, the connecting portion being located on an inner peripheral side of the impeller cup, and the fan units are connected to each other in the rotation axis direction via each of the connecting portions; In an axial flow fan, in the vicinity of the connection portion, no other members are present on the outer circumferential side of each of the accommodating portions, and a space for drawing out lead wires connected to the motor is open.

2. At least each of the housing portions is made of resin, 2. The axial flow fan of claim 1, wherein each of said bushings is made of metal.

3. the axial flow fan has a bearing that rotatably supports the rotor with respect to the base portion, Each of the base portions has a bush that supports the bearing and a bush support portion that supports the bush, The axial flow fan according to claim 1 , wherein the connecting portion is provided on an axial end surface of each of the bushing supports.

4. The axial flow fan according to claim 3 , wherein at least each of the housing portions is made of metal.

5. The axial flow fan according to claim 1 , wherein the connecting portions are connected to each other by threaded engagement.

6. The axial flow fan according to claim 1 , wherein the connecting portions are connected to each other by press-fitting.

7. The axial flow fan according to claim 1 , wherein a positioning portion is provided on an end surface of each of the base portions in the axial direction.

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