JP7087841B2 - Series axial flow fan - Google Patents

Description

The present disclosure relates to a series axial flow fan.

Conventionally, a series type axial flow fan in which two axial flow fans are connected in the axial direction to increase the amount of air blown is known. In the series-type axial flow fan, the airflow sent from the front-stage axial flow fan that sucks the air outside the series-type axial flow fan is sucked into the rear-stage axial flow fan. The airflow whose flow velocity is increased by the axial flow fan in the subsequent stage is sent from the axial flow fan in the subsequent stage to the outside of the series axial flow fan. Here, the flow of the airflow sent from the axial flow fan in the previous stage has the same swirling component as the rotation direction of the impeller in addition to the axial component. However, it is difficult for the swirling component of the air flow to flow in the axial direction by the axial flow fan in the subsequent stage.

Therefore, for example, in the unit type fan of JP-A-2003-56498, by locating the static blade fan frame structure between the two heat-dissipating fans, interference between the two heat-dissipating fans is suppressed and heat is dissipated. Increases the air volume and pressure of the airflow generated when the fan is operating.

Further, in Chinese Patent Application Publication No. 201246347, a fan casing is attached to the exhaust side of the axial flow fan. In the fan casing, a convex portion having a honeycomb structure is provided, and a plate-shaped frame screwed to the axial flow fan extends from the outer surface of the convex portion in a direction perpendicular to the axial direction. The convex portion having the honeycomb structure guides the airflow sent from the axial flow fan to make the airflow more concentrated.

Japanese Patent Application Laid-Open No. 2003-56498 Chinese Patent Application Publication No. 201246347

By the way, in the connecting portion of the two axial flow fans, a recess recessed in the axial direction from the connecting portion may be provided in the housing of the axial flow fan in order to draw out the lead wire extending from the motor portion to the outside. In this case, a part of the airflow sent from the axial flow fan in the previous stage tends to flow to the outside of the series axial flow fan through the recess. Therefore, turbulence is likely to occur in the vicinity of the recess. The generation of such turbulence affects the ventilation efficiency of the series axial fan.

It is an object of the present disclosure to further improve the ventilation efficiency of a series axial fan.

The exemplary series axial flow fan of the present disclosure is partitioned by a grid-like partition wall from a first axial flow fan, a second axial flow fan connected in series with the first axial flow fan, and axially. It is provided with a straightening vane in which a plurality of hollow cells penetrating are uniformly arranged two-dimensionally up to the outer edge portion. The first axial flow fan has a first impeller having a first blade that can rotate about a central axis extending in the vertical direction, and a first motor unit that drives the first impeller to rotate the first blade. A first housing having a cylindrical shape extending in the axial direction and having a first tubular portion accommodating the first impeller and the first motor portion, and a first lead wire extending from the first motor portion. .. The second axial flow fan includes a second impeller having a second blade that can rotate about the central axis, a second motor unit that drives the second impeller to rotate the second blade, and a shaft. It has a second housing having a cylindrical shape extending in a direction and having a second tubular portion for accommodating the second impeller and the second motor portion, and a second lead wire extending from the second motor portion. The axial lower end of the first housing and the axial upper end of the second housing are directly connected. The straightening vane is provided at a connecting portion between the first housing and the second housing. The lower end portion in the axial direction of the first cylinder portion faces the upper end portion in the axial direction of the second cylinder portion in the axial direction via the straightening vane. The axial end surface of at least one of the axial lower end surface of the first cylinder portion and the axial upper end surface of the second cylinder portion has a recess recessed on the side opposite to the axial connection portion. It will be provided. At least one of the first lead wire and the second lead wire is housed in the recess. At least a part of the recess overlaps with a part of the straightening vane in the axial direction.

According to the exemplary series axial fan of the present disclosure, the ventilation efficiency of the serial axial fan can be further improved.

FIG. 1 is a perspective view showing an example of a series-type axial flow fan according to an embodiment. FIG. 2 is a cross-sectional view of a series axial flow fan along the alternate long and short dash line AA of FIG. FIG. 3 is a cross-sectional view of a series axial flow fan along the alternate long and short dash line BB of FIG. FIG. 4A is a perspective view showing a first example of a band-shaped member covering the first opening. FIG. 4B is a perspective view showing a second example of the band-shaped member covering the first opening. FIG. 4C is a perspective view showing a third example of the band-shaped member covering the first opening. FIG. 5 is a cross-sectional view showing an example of a second recess provided in the second cylinder portion. FIG. 6 is a cross-sectional view showing an example of a second leg portion provided in the second cylinder portion. FIG. 7 is a perspective view showing an example of a straightening vane. FIG. 8 is a cross-sectional view of the series axial flow fan according to the first modification. FIG. 9 is a perspective view showing an example of a series-type axial flow fan according to the second modification. FIG. 10 is a perspective view showing an example of a series-type axial flow fan according to a third modification. FIG. 11 is a cross-sectional view of a series axial flow fan along the alternate long and short dash line EE of FIG. FIG. 12 is a cross-sectional view showing an example of the second wall portion.

An exemplary embodiment of the present disclosure will be described below with reference to the drawings.

In the present specification, in the series axial flow fan 100, the direction parallel to the central axis CA is referred to as "axial direction". In the axial direction, the direction from the second axial flow fan 2 described later to the first axial flow fan 1 described later is called "upper axial direction", and the direction from the first axial flow fan 1 to the second axial flow fan 2 is called. Called "downward in the axial direction". In each component, the upper end in the axial direction is referred to as the "upper end in the axial direction", and the position of the upper end in the axial direction in the axial direction is referred to as the "upper end in the axial direction". Further, the lower end portion in the axial direction is referred to as an "axial lower end portion", and the position of the axial lower end portion in the axial direction is referred to as an "axial lower end portion". Further, on the surface of each component, the surface facing the upper side in the axial direction is referred to as an "upper surface in the axial direction", and the surface facing the lower side in the axial direction is referred to as an "lower end surface in the axial direction". Further, the generic term of "axial upper end surface" and "axial lower end surface" is referred to as "axial end surface".

The direction orthogonal to the central axis CA is referred to as "diametrical direction", and the direction of rotation about the central axis CA is referred to as "circumferential direction". In the radial direction, the direction toward the central axis CA is referred to as "diametrically inner", and the direction away from the central axis CA is referred to as "diametrically outer". In each component, the inner end in the radial direction is referred to as the "inner end in the radial direction", and the position of the inner end in the radial direction is referred to as the "inner end in the radial direction". Further, the end portion on the outer side in the radial direction is referred to as the "outer end portion in the radial direction", and the position of the outer end portion in the radial direction is referred to as the "outer end portion in the radial direction". Further, on the side surface of each component, the side surface facing inward in the radial direction is referred to as "diameter inner side surface", and the side surface facing outward in the radial direction is referred to as "diameter outer surface".

It should be noted that the names such as the direction, the end, the position, and the surface described above do not indicate the positional relationship and the direction when they are incorporated in an actual device.

<1. Embodiment>
FIG. 1 is a perspective view showing an example of a series-type axial flow fan 100 according to an embodiment. FIG. 2 is a cross-sectional view of the series axial flow fan 100 along the alternate long and short dash line AA of FIG. FIG. 3 is a cross-sectional view of the series axial flow fan 100 along the alternate long and short dash line BB of FIG. Note that FIG. 2 shows a cross-sectional structure in which the series axial flow fan 100 is cut in a virtual plane perpendicular to the axial direction. Further, FIG. 3 shows a cross-sectional structure when the series axial flow fan 100 is cut in a virtual plane including the central axis CA.

<1-1. Fan motor configuration>
As shown in FIG. 1, the serial axial flow fan 100 includes a first axial flow fan 1, a second axial flow fan 2, and a straightening vane 3. The series-type axial flow fan 100 is a blower device in which a first-stage axial flow fan 1 in the front stage and a second-stage axial flow fan 2 in the rear stage are connected in series with a straightening vane 3 interposed therebetween.

As described above, the series axial flow fan 100 includes a first axial flow fan 1. The first axial flow fan 1 has a first impeller 11, a first motor unit 12, a first housing 13, and a first lead wire 14. The first housing 13 has a first cylinder portion 131, a first flange portion 132, and a first rib 133. Further, the series axial flow fan 100 includes a second axial flow fan 2 as described above. The second axial flow fan 2 is connected in series with the first axial flow fan 1. The second axial flow fan 2 has a second impeller 21, a second motor unit 22, a second housing 23, and a second lead wire 24. The second housing 23 has a second cylinder portion 231, a second flange portion 232, and a second rib 233.

In the following, the generic names of the first housing 13 and the second housing 23 will be referred to as "housings 13 and 23". Further, the generic term of the first lead wire 14 and the second lead wire 24 is referred to as "lead wires 14, 24". Further, the generic name of the first cylinder portion 131 and the second cylinder portion 231 is referred to as "tube portion 131, 231". Further, the generic name of the first flange portion 132 and the second flange portion 232 is referred to as "flange portion 132, 232". Further, the generic name of the first rib 133 and the second rib 233 is referred to as "rib 133, 233". The description of each component of the first axial flow fan 1 and the second axial flow fan 2 will be described later.

The straightening vane 3 is provided at the connecting portion 100a between the first housing 13 and the second housing 23. The rectifying plate 3 provided in the connecting portion 100a between the first housing 13 and the second housing 23 rectifies the airflow sent downward in the axial direction from the first axial flow fan 1. The second axial flow fan 2 sucks the airflow rectified by the rectifying plate 3. The rectified airflow has a small swirling component and easily flows in the axial direction by the second axial flow fan 2. As a result, the pressure and the air volume of the airflow sent from the second axial flow fan 2 increase. As a result, the amount of air sucked or sent out by the series axial fan 100 can be increased. Therefore, the ventilation efficiency of the series axial flow fan 100 can be further improved. The material of the straightening vane 3 is aluminum in this embodiment, but the material is not limited to this example, and other metal materials, ceramic materials, and the like may be used. A more detailed configuration of the straightening vane 3 will be described later.

<1-2. 1st axis flow fan>
Next, each component of the first axial flow fan 1 will be described with reference to FIGS. 1 to 3.

The first axial flow fan 1 has a first impeller 11 as described above. The first impeller 11 has a first blade 111. The first blade 111 is rotatable about a central axis CA extending in the vertical direction. When the first motor unit 12 drives the first impeller 11, the first blade 111 rotates about the central axis CA. As a result, the first axial flow fan 1 sucks air from the axial upper side of the series axial flow fan 100 at the upper end portion in the axial direction of the first axial flow fan 1. The first axial flow fan 1 generates an air flow flowing downward in the axial direction, and sends out the airflow from the lower end portion in the axial direction of the first axial flow fan 1.

As described above, the first axial flow fan 1 has a first motor unit 12. The first motor unit 12 drives the first impeller 11 to rotate the first blade 111. The lower end portion in the axial direction of the first motor unit 12 may be in contact with the upper end surface in the axial direction of the straightening vane 3. Alternatively, the axial lower end portion of the first motor unit 12 may have a gap from the axial upper end surface of the straightening vane 3 and face axially.

The first axial flow fan 1 has a first housing 13 as described above. As described above, the first housing 13 has a first cylinder portion 131. The first cylindrical portion 131 has a cylindrical shape extending in the axial direction, and houses the first impeller 11 and the first motor portion 12 inside. The lower end portion in the axial direction of the first cylinder portion 131 faces the upper end portion in the axial direction of the second cylinder portion 231 via the straightening vane 3. Further, the lower end portion in the axial direction of the first cylinder portion 131 abuts on the upper end surface in the axial direction of the straightening vane 3 in the present embodiment. By doing so, it is possible to prevent the airflow from flowing in the radial direction at the lower end portion in the axial direction of the first cylinder portion 131. Therefore, it is possible to prevent the occurrence of turbulent flow at the lower end portion of the first cylinder portion 131 in the axial direction. However, the present invention is not limited to this example, and there may be a gap between the first cylinder portion 131 and the straightening vane 3 in the axial direction.

Further, in the present embodiment, the lower end surface of the first cylinder portion 131 in the axial direction is provided with the first concave portion 131a recessed on the side opposite to the connecting portion 100a in the axial direction. The first concave portion 131a is recessed upward in the axial direction on the lower end surface in the axial direction of the first tubular portion 131, and penetrates the first tubular portion 131 in the radial direction.

Further, the first housing 13 further has a first flange portion 132 as described above. The first flange portion 132 extends radially outward from the axial end portion on the connecting portion 100a side of the first cylinder portion 131. In other words, the first flange portion 132 extends radially outward from the axial lower end portion of the first cylinder portion 131. Further, a first flat surface portion 132a and a first leg portion 132b are provided on the lower end surface of the first flange portion 132 in the axial direction. The first flat surface portion 132a abuts on the axial upper end surface of the straightening vane 3. The first leg portion 132b projects downward in the axial direction of the first flange portion 132. There are a plurality of first leg portions 132b, each of which is provided in the circumferential direction. The lower end portion in the axial direction of the first leg portion 132b abuts on the second flange portion 232. As a result, in the axial direction, a space for accommodating the straightening vane 3 is provided between the first cylinder portion 131 and the second cylinder portion 231. The axial length df1 shown in FIG. 3 of the first leg portion 132b is equal to or less than the axial length dc shown in FIG. 7, which will be described later, of the straightening vane 3. The axial length df1 of the first leg portion 132b is the axial width between the first plane portion 132a and the axial lower end portion of the first leg portion 132b. Therefore, the straightening vane 3 is sandwiched and held between the lower end portion in the axial direction of the first cylinder portion 131 and the upper end portion in the axial direction of the second cylinder portion 231 in the axial direction. Further, when viewed from the axial direction, the first leg portion 132b is provided radially outside the first recess 131a.

Further, the first housing 13 further has a first rib 133 as described above. The radial inner end of the first rib 133 supports the first motor portion 12. The radial outer end of the first rib 133 is connected to the first tubular portion 131.

The first rib 133 has a gap with the axial upper end surface of the straightening vane 3 and faces in the axial direction. The minimum axial width of the gap (Wri1 in FIG. 3) is narrower than the width of the straightening vane 3 in the direction perpendicular to the axial direction (for example, the width Wc shown in FIG. 7). By doing so, a gap narrower than the width in the direction perpendicular to the axial direction of the hollow cell 3a is provided between the first rib 133 and the rectifying plate 3, so that the rectifying effect of the first rib 133 is maintained and the rectifying effect is maintained. It is possible to prevent a decrease in the amount of air flow passing through the hollow cell 3a that overlaps with the rib 133 in the axial direction. This is because when there is no gap between the first rib 133 and the straightening vane 3 in the axial direction, the amount of air flow passing through the hollow cell 3a that overlaps the first rib 133 in the axial direction is small. On the other hand, if the axial width of the gap between the first rib 133 and the rectifying plate 3 is too wide, the effect of rectifying the airflow flowing in the axial direction by the first rib 133 is reduced.

Further, the axial width Wri1 of the gap in the radial direction between the first rib 133 and the axial upper end surface of the straightening vane 3 is the radial outer gap between the first rib 133 and the axial upper end surface of the straightening vane 3. It is smaller than the axial width Wro1. In the present embodiment, as shown in FIG. 3, the axial width Wri1 is smaller than the width Wc between the two sides of the hexagonal hollow cell 3a in the straightening vane 3. On the other hand, the axial width Wro1 is larger than the width Wc between the two sides of the hexagonal hollow cell 3a. The optimum value of the axial width of the gap for improving the air pressure and the air volume and suppressing the generation of turbulence differs between the radial inner side and the radial outer side of the first rib 133. In particular, the optimum value is affected by the radial inner surface of the first cylinder portion 131 and the like at the radial outer end portion of the first rib 133. Therefore, by making the axial width Wro1 of the gap larger than the width Wc between the two sides of the hollow cell 3a, the pressure-air volume characteristic of the series axial flow fan 100 can be improved.

Further, the width dr1 of the portion of the first rib 133 facing the straightening vane plate 3 in the axial direction is preferably not more than the width Wc between the two sides of the hexagonal hollow cell 3a. The portion is, for example, the lower end portion in the axial direction of the first rib 133. The width dr1 is, for example, the minimum width in the direction perpendicular to the axial direction of the first rib 133. By doing so, the pressure and the air volume of the airflow flowing through the straightening vane 3 from the first axial flow fan 1 to the second axial flow fan 2 can be improved, and the generation of turbulent flow can be suppressed.

Further, in the present embodiment, the first housing 13 is provided with four first openings 13a as shown in FIG. The first opening 13a is provided at the lower end portion in the axial direction of the first housing 13, and is recessed upward in the axial direction. Further, the first opening 13a penetrates the first housing 13 in the radial direction, and particularly penetrates a part of the first cylinder portion 131 and a part of the first flange portion 132 in the radial direction. In the first opening 13a, the radial outer end surface of the straightening vane 3 is exposed to the outside of the series axial flow fan 100. The radial outer end of the straightening vane 3 is located at the same position as the first opening 13a as shown in FIG. 2, or is radially inside the first opening 13a.

Not limited to the example of FIG. 1, the straightening vane 3 does not have to be exposed at the first opening 13a. For example, the series axial flow fan 100 may further include a strip-shaped member 4 provided on the radial outer surface of the connecting portion 100a. In other words, the strip-shaped member 4 may cover the first opening 13a. 4A to 4C are perspective views showing first to third examples of the band-shaped member 4 covering the first opening 13a, respectively.

For example, as shown in FIG. 4A, all the first openings 13a may be covered with the band-shaped member 4. By doing so, the band-shaped member 4 provided for each first opening 13a can suppress or prevent air leakage in all the first openings 13a of the connecting portion 100a.

Alternatively, as shown in FIG. 4B, a part of the first opening 13a may be covered with the band-shaped member 4. By doing so, since only a part of the plurality of first openings 13a is covered with the band-shaped member 4, the band-shaped member 4 can be saved.

The band-shaped member 4 is provided for each first opening 13a in FIGS. 4A and 4B, but may be provided in a continuous manner as shown in FIG. 4C. That is, the strip-shaped member 4 may be wound around the entire circumference in the circumferential direction on the radial outer surface of the connecting portion 100a. This facilitates the work of providing the strip-shaped member 4.

Next, the first axial flow fan 1 has the first lead wire 14 as described above. The first lead wire 14 extends from the first motor unit 12. In the present embodiment, the first lead wire 14 is housed in the first recess 131a. More specifically, the first lead wire 14 is inserted into the first recess 131a and is drawn out of the first housing 13 through the first recess 131a.

<1-3. 2nd axis flow fan>
Next, each component of the second axial flow fan 2 will be described with reference to FIGS. 1 and 3.

The second axial flow fan 2 has a second impeller 21 as described above. The second impeller 21 has a second blade 211. The second blade 211 is rotatable about a central axis CA extending in the vertical direction. When the second motor unit 22 drives the second impeller 21, the second blade 211 rotates about the central axis CA. As a result, the second axial flow fan 2 sucks the airflow sent from the first axial flow fan 1 at the upper end portion in the axial direction of the second axial flow fan 2 via the straightening vane 3. The second axial flow fan 2 accelerates the flow velocity of the airflow flowing downward in the axial direction, and sends the airflow from the lower end portion in the axial direction of the second axial flow fan 2 to the lower side in the axial direction of the series axial flow fan 100. ..

The second axial flow fan 2 has a second motor unit 22 as described above. The second motor unit 22 drives the second impeller 21 to rotate the second blade 211.

The second axial flow fan 2 has a second housing 23 as described above. The second housing 23 has a second tubular portion 231 as described above. The second cylindrical portion 231 has a cylindrical shape extending in the axial direction, and houses the second impeller 21 and the second motor portion 22 inside. The axial upper end portion of the second tubular portion 231 abuts on the axial lower end surface of the straightening vane 3 in the present embodiment. By doing so, it is possible to prevent the air flow from flowing in the radial direction at the upper end portion in the axial direction of the second cylinder portion 231. Therefore, it is possible to prevent the occurrence of turbulent flow at the upper end portion of the second cylinder portion 231 in the axial direction. However, the present invention is not limited to this example, and there may be a gap between the second cylinder portion 231 and the straightening vane 3 in the axial direction.

Further, the second housing 23 further has a second flange portion 232 as described above. The second flange portion 232 extends radially outward from the axial end portion on the connecting portion 100a side of the second cylinder portion 231. In other words, the second flange portion 232 extends radially outward from the axial upper end portion of the second cylinder portion 231. The second flange portion 232 is connected to the first flange portion 132. As a result, the axial lower end of the first housing 13 and the axial upper end of the second housing 23 are directly connected. By doing so, it is possible to secure the same assemblability as the configuration in which the straightening vane 3 is not provided in the connecting portion 100a between the first housing 13 and the second housing 23.

A second flat surface portion 232a is provided on the upper end surface of the second flange portion 232 in the axial direction. The second flat surface portion 232a abuts on the lower end surface in the axial direction of the straightening vane 3. In the following, the first flat surface portion 132a and the second flat surface portion 232a are collectively referred to as "flat surface portions 132a and 232a". As described above, in the present disclosure, the first flange portion 132 and the second flange portion 232 are provided with flat surface portions 132a and 232a that abut on the axial end faces of the straightening vane 3. As a result, the straightening vane 3 provided between the first cylinder portion 131 and the second cylinder portion 231 can be sandwiched between the first flat surface portion 132a and the second flat surface portion 232a. Therefore, the straightening vane 3 can be held more reliably in the axial direction. However, the present invention is not limited to this example, and there may be a gap between at least one of the first flange portion 132 and the second flange portion 232 and the straightening vane 3 in the axial direction. By providing such a gap, it is possible to suppress the vibration of the straightening vane 3 and the generation of noise associated therewith.

Further, the second housing 23 further has a second rib 233 as described above. The radial inner end of the second rib 233 supports the second motor portion 22. The radial outer end of the second rib 233 is connected to the second tubular portion 231.

The second axial flow fan 2 has a second lead wire 24 as described above. The second lead wire 24 extends from the second motor unit 22.

<1-4. Modification example of the 1st axis flow fan and the 2nd axis flow fan>
<1-4-1. Deformation example of the first recess>
In the above-described embodiment, as shown in FIG. 3, a first recess 131a for pulling out the first lead wire 14 to the outside of the first housing 13 is provided in the first cylinder portion 131. Similarly, as shown in FIG. 5, a second recess 231a for pulling out the second lead wire 24 to the outside of the second housing 23 may be provided in the second cylinder portion 231. FIG. 5 shows an example of the second recess 231a provided in the second cylinder portion 231. Note that FIG. 5 corresponds to the portion C surrounded by the broken line in FIG. In FIG. 5, a second recess 231a recessed on the side opposite to the axial connecting portion 100a is provided on the axial upper end surface of the second tubular portion 231. The second concave portion 231a is recessed downward in the axial direction on the axial upper end surface of the second tubular portion 231 and penetrates the second tubular portion 231 in the radial direction. The serial axial flow fan 100 may be provided with both the first recess 131a and the second recess 231a, or may be provided with the second recess 231a in place of the first recess 131a. Further, in the following, the generic name of the first recess 131a and the second recess 231a will be referred to as "recess 131a, 231a". As described above, in the present disclosure, the axial end surface of at least one of the axial lower end surface of the first tubular portion 131 and the axial upper end surface of the second tubular portion 231 is the axial end surface of the tubular portion 131 and 231. Recesses 131a and 231a recessed on the opposite side of the connecting portion 100a are provided.

Further, in FIG. 3, the first lead wire 14 is pulled out of the first housing 13 through the first recess 131a, and in FIG. 5, the second lead wire 24 is pulled out of the second housing 23 through the second recess 231a. However, the present invention is not limited to these, and both the first lead wire 14 and the second lead wire 24 may be drawn out of the housings 13 and 23 through the first recess 131a or the second recess 231a. That is, in the present disclosure, at least one of the lead wires 14 and 24 of the first lead wire 14 and the second lead wire 24 is accommodated in the recesses 131a and 231a.

Further, in the present disclosure, at least a part of the recesses 131a and 231a provided in at least one of the axial lower end surface of the first cylinder portion 131 and the axial upper end surface of the second cylinder portion 231 is preferably rectified. It overlaps a part of the plate 3 in the axial direction. By doing so, even if at least one of the lead wires 14 and 24 accommodated in the recesses 131a and 231a is bent, the movement of the lead wires 14 and 24 toward the connecting portion 100a in the axial direction can be suppressed by the straightening vane 3. .. Further, the turbulence of the airflow caused by the recesses 131a and 231a can be suppressed by the straightening vane 3. Therefore, the pressure-air volume characteristic of the series-type axial flow fan 100 can be improved, and the ventilation efficiency of the series-type axial flow fan 100 can be further improved. It is also possible to reduce the noise generated by the series axial flow fan 100.

Further, in the present disclosure, the radial outer end of the straightening vane 3 is preferably the same as the radial outer end of the recesses 131a and 231a, or has a diameter larger than the radial outer end of the recesses 131a and 231a when viewed from the axial direction. Inside the direction. In this way, the radial outer end of the straightening vane 3 is not radially outer than the radial outer ends of the recesses 131a and 231a when viewed from the axial direction. Therefore, for example, as shown in FIG. 3, even when the second lead wire 24 extends axially along the radial outer surface of the second cylinder portion 231 to the radial outer end portion of the first recess 131a, the straightening vane 3 The radial outer end does not become an obstacle. Therefore, the arrangement of the second lead wire 24 can be designed more freely. Further, at this time, since the radial outer end portion of the straightening vane 3 is not pushed inward in the radial direction by the second lead wire 24, deformation of the radial outer end portion of the straightening vane 3 can be prevented.

<1-4-2. Deformation example of the first leg>
In the above embodiment, for example, as shown in FIG. 3, the first leg portion 132b is provided on the first flange portion 132. Similarly, as shown in FIG. 6, a second leg portion 232b projecting upward in the axial direction may be provided on the second flange portion 232. FIG. 6 is a cross-sectional view showing an example of the second leg portion 232b provided in the second cylinder portion 231. Further, FIG. 6 corresponds to the portion D surrounded by the broken line in FIG. The series axial flow fan 100 may be provided with a second leg portion 232b instead of the first leg portion 132b. Alternatively, both the first leg portion 132b and the second leg portion 232b may be provided as shown in FIG. Further, the upper end portion in the axial direction of the second leg portion 232b may abut on the first flange portion 132, or may abut on the first leg portion 132b as shown in FIG. In the following, the generic term for the first leg portion 132b and the second leg portion 232b will be referred to as "leg portion 132b, 232b".

As described above, in the present disclosure, the leg portion 132b protruding in the axial direction is provided on the axial end surface of at least one of the flange portions 132 and 232 of the first flange portion 132 and the second flange portion 232 on the connecting portion 100a side. 232b is provided. The leg portions 132b and 232b provided on one flange portion 132 and 232 abut on the other flange portion 132 and 232 or the leg portions 132b and 232b provided on the other flange portion 132 and 232. By doing so, it is possible to provide a space having the same axial length as the leg portions 132b and 232b between the first cylinder portion 131 and the second cylinder portion 231 in the axial direction. Therefore, by connecting the first flange portion 132 and the second flange portion 232, the first housing 13 and the second housing 23 can be directly connected, and between the first cylinder portion 131 and the second cylinder portion 231. The straightening vane 3 can be accommodated in the space in the axial direction of the above.

Further, the second leg portion 232b is provided radially outside the second recess 231a in FIG. 6. As described above, in the present disclosure, the legs 132b and 232b are provided radially outside the recesses 131a and 231a when viewed from the axial direction. In this way, the legs 132b and 232b do not overlap with the recesses 131a and 231a in the axial direction. Therefore, the lead wires 14 and 24 can be easily accommodated in the recesses 131a and 231a, and the straightening vane 3 and the recesses 131a and 231a can be easily overlapped in the axial direction. Further, in the portion of the straightening vane 3 that overlaps with the recesses 131a and 231a, the airflow can be smoothly flowed in the axial direction without being affected by the legs 132b and 232b. Further, when the housings 13 and 23 having the leg portions 132b and 232b on the flange portions 132 and 232 are molded by the mold, the mold can be opened in the vertical direction. Therefore, the mold structure can be simplified, and the molding steps of the housings 13 and 23 using the mold can be easily carried out.

Further, the axial length df2 shown in FIG. 6 of the second leg portion 232b is equal to or less than the axial length dc shown in FIG. 7 of the straightening vane 3. The axial length df2 of the second leg portion 232b is the axial width between the second plane portion 232a and the axial upper end portion of the second leg portion 232b. In the following, the axial length df1 of the first leg portion 132b and the axial length df2 of the second leg portion 232b are collectively referred to as “axial length df”. As described above, in the present disclosure, the axial length df of the legs 132b and 232b is equal to or less than the axial length dc of the straightening vane 3. The axial length df of the legs 132b and 232b is the axial end of the flanges 132a and 232 on which the legs 132b and 232b are provided, and the axial ends of the legs 132b and 232b on the connecting portion 100a side. Axial width between and. By doing so, the straightening vane 3 can be sandwiched and held between the axial lower end portion of the first cylinder portion 131 and the axial upper end portion of the second cylinder portion 231 in the axial direction.

Further, there are a plurality of second leg portions 232b, each of which is provided in the circumferential direction. That is, there are a plurality of legs 132b and 232b, each of which is provided in the circumferential direction.

<1-5. Rectifying plate>
Next, the configuration of the straightening vane 3 will be described with reference to FIG. 7. FIG. 7 is a perspective view showing an example of the straightening vane 3.

As described above, the series axial flow fan 100 includes a straightening vane 3. The straightening vane 3 includes a plurality of hollow cells 3a and a grid-like partition wall 31. Each of the hollow cells 3a of the straightening vane 3 is partitioned by a partition wall 31 and penetrates in the axial direction. Further, the plurality of hollow cells 3a are uniformly arranged two-dimensionally from the central portion to the outer edge portion of the straightening vane 3. According to such a structure, a frame or the like is not provided on the outer edge portion of the straightening vane 3. Therefore, the rectifying effect of the airflow by the hollow cell 3a can be obtained up to the outer edge portion. Further, the straightening vane 3 can be created without using a mold or the like. In other words, the plurality of hollow cells 3a have a structure partitioned by a grid-shaped partition wall 31 and penetrate the straightening vane 3 in the axial direction. Therefore, the straightening vane 3 can secure the maximum air flow path in the axial direction.

In the present embodiment, the straightening vane 3 has a honeycomb structure in which hexagonal hollow cells 3a are two-dimensionally arranged when viewed from the axial direction. By doing so, by adopting the honeycomb structure for the rectifying plate 3, the effect of rectifying the airflow sent from the first axial flow fan 1 can be improved and the air resistance at the time of rectification can be reduced. Therefore, the pressure-air volume characteristic of the series axial flow fan 100 can be enhanced. However, the present invention is not limited to this example, and the shape of the hollow cell 3a seen from the axial direction may be a polygonal shape other than a hexagonal shape, a circular shape, or the like.

The aperture ratio of the hollow cell 3a of the straightening vane 3 having the honeycomb structure is 90% or more. The aperture ratio here is a ratio of the total area of the openings of all the hollow cells 3a whose entire circumference is partitioned by the partition wall 31 to the total area of the axial end faces of the straightening vane 3. With a straightening vane formed by resin molding or the like, it is difficult to increase the aperture ratio to 90% or more. By setting the aperture ratio of the straightening vane 3 having a honeycomb structure to 90% or more, it is possible to realize a higher rectifying effect and a lower air resistance than the straightening vane having another structure formed by resin molding. ..

The width Wc between the two sides of the hexagonal hollow cell 3a extending in parallel and facing each other is larger than the radial width of the axial end portion of the first cylinder portion 131 and the second cylinder portion 231 on the connecting portion 100a side. .. That is, the width Wc is larger than the radial width dt1 shown in FIG. 2 at the axial lower end of the first cylinder 131 and the radial width of the axial upper end of the second cylinder 231. In this way, in the hollow cell 3a that overlaps the axial end portion on the connecting portion 100a side of the first cylinder portion 131 and the second cylinder portion 231 when viewed from the axial direction, the axial end portion completely covers the hollow cell 3a. You can avoid it. Therefore, when viewed from the axial direction, the hollow cell 3a that overlaps the axial end portion on the connecting portion 100a side of the first cylinder portion 131 and the second cylinder portion 231 can be used near the inner wall of the first cylinder portion 131 and the second cylinder portion 231. The flowing airflow can be rectified. Therefore, it is possible to suppress or prevent the generation of turbulent flow in the vicinity of the inner wall at the axial end portion of the first cylinder portion 131 and the second cylinder portion 231.

<2. Modification example of embodiment>
Next, a modification of the embodiment will be described. Hereinafter, a configuration different from the above-described embodiment will be described. Further, the same components as those in the above-described embodiment are designated by the same reference numerals, and the description thereof may be omitted.

<2-1. First modification>
In the above-described embodiment, the second rib 233 is provided at the lower portion in the axial direction of the second axial flow fan 2 (see FIG. 3). However, the present invention is not limited to this example, and the second rib 233 may be provided at the upper portion in the axial direction of the second axial flow fan 2.

FIG. 8 is a cross-sectional view showing a first modification of the series axial flow fan 101 according to the first modification. Note that FIG. 8 shows a cross-sectional structure when the series axial flow fan 101 is cut on a virtual plane including the central axis CA. In FIG. 8, the arrangement of each component of the first axial flow fan 1 and the straightening vane 3 is the same as that in FIG. However, the arrangement of each component of the second axial flow fan 2 is reversed in the vertical direction from that of FIG.

In the first modification, the second rib 233 has a gap with the axial lower end surface of the straightening vane 3 and faces in the axial direction. The minimum axial width of the gap (Wri2 in FIG. 8) is preferably narrower than the width of the straightening vane 3 in the direction perpendicular to the axial direction of the hollow cell 3a (for example, the width Wc shown in FIG. 7). By doing so, a gap narrower than the width in the direction perpendicular to the axial direction of the hollow cell 3a is provided between the second rib 233 and the rectifying plate 3, so that the rectifying effect of the second rib 233 is maintained and the rectifying effect is maintained. It is possible to prevent a decrease in the amount of air flow passing through the hollow cell 3a that overlaps the 2 ribs 233 in the axial direction.

As described above, according to the above-described embodiment and the first modification, at least one of the first rib 133 and the second rib 233, the ribs 133 and 233, face each other in the axial direction via the straightening vane 3. The minimum axial width of the gap between the second rib 233 and the straightening vane 3 is preferably narrower than the width Wc between the two sides of the hexagonal hollow cell 3a of the straightening vane 3 having a honeycomb structure. By doing so, the gap between the at least one rib 133, 233 and the straightening vane 3 is provided to be narrower than the width Wc in the direction perpendicular to the axial direction of the hollow cell 3a, so that the at least one rib 133, 233 is formed. While maintaining the rectifying effect, it is possible to prevent a decrease in the amount of air flow passing through the hollow cell 3a axially overlapping with at least one of the ribs 133 and 233. The reason is that when there is no gap between at least one of the ribs 133 and 233 and the straightening vane 3 in the axial direction, the size of the opening on the inlet side and the outlet side of the hollow cell 3a is different. This causes a decrease in the effect of the straightening vane 3. Further, if the axial width of the gap between the at least one rib 133 and 233 and the straightening vane 3 is too wide, the effect of rectifying the airflow flowing in the axial direction by the at least one rib 133 and 233 is reduced. ..

Further, the axial width Wri2 of the gap in the radial direction between the second rib 233 and the axial lower end surface of the straightening vane 3 is preferably the radial outer side of the axial lower end surface of the second rib 233 and the straightening vane 3. It is smaller than the axial width Wro2 of the gap in. In the following, the axial width Wri1 of the gap inside the radial direction between the first rib 133 and the straightening vane 3 and the axial width Wri2 of the gap inside the radial direction between the second rib 233 and the straightening vane 3 are generically referred to. Is called "axial width Wri". Further, the axial width Wro1 of the gap on the radial outer side between the first rib 133 and the straightening vane 3 and the axial width Wro2 of the gap on the radial outer side between the second rib 233 and the straightening plate 3 are collectively referred to as "axis". It is called "direction width Wro".

Further, in the present embodiment, as shown in FIG. 7, the axial width Wri2 is smaller than the width Wc between the two sides of the hexagonal hollow cell 3a in the straightening vane 3. On the other hand, the axial width Wro is larger than the width Wc between the two sides of the hexagonal hollow cell 3a. As described above, in the present disclosure, the axial width Wri of the gap between the radial inner end portion of the ribs 133 and 233 and the straightening vane 3 is smaller than the width Wc between the two sides of the hexagonal hollow cell. On the other hand, the axial width Wro of the gap between the radial outer end of the ribs 133 and 233 and the straightening vane 3 is larger than the width Wc between the two sides of the hexagonal hollow cell 3a. The optimum value of the axial width of the gap for improving the air pressure and air volume and suppressing the generation of turbulence differs between the radial inner end and the radial outer end of the ribs 133 and 233. .. The radial outer ends of the ribs 133 and 233 are susceptible to the radial inner surfaces of the tubular portions 131 and 231. Therefore, by making the axial width Wro of the gap larger than the width Wc between the two sides of the hollow cell 3a, the pressure-air volume characteristic of the series axial flow fan 101 can be improved.

Further, the width of the portion of the second rib 233 facing the straightening vane 3 in the axial direction is preferably not more than the width Wc between the two sides of the hexagonal hollow cell 3a. The portion is, for example, the upper end portion in the axial direction of the second rib 233. The width is, for example, the minimum width in the direction perpendicular to the axial direction of the second rib 233. That is, in the first modification, the width of the portion of at least one of the ribs 133 and 233 that faces the straightening vane 3 in the axial direction is equal to or less than the width (Wc) between the two sides of the hexagonal hollow cell 3a. By doing so, since the hexagonal hollow cell 3a is not blocked by at least one of the ribs 133 and 233, the pressure of the airflow flowing through the straightening vane 3 from the first axial flow fan 1 to the second axial flow fan 2 and The air volume can be improved and the generation of turbulent flow can be suppressed.

Further, in the first modification, the lower end portion in the axial direction of the first motor portion 12 faces the upper end portion in the axial direction of the second motor portion 22 via the straightening vane 3. Here, at least one of the axial lower end portion of the first motor unit 12 and the axial upper end portion of the second motor unit 22 may be in contact with the axial end surface of the straightening vane 3. For example, when both the lower end portion in the axial direction of the first motor unit 12 and the upper end portion in the axial direction of the second motor unit 22 come into contact with the straightening vane 3, the straightening vane 3 is pressed by the first motor unit 12 and the second motor unit 22. Can be pinched and held. Alternatively, both the axial lower end portion of the first motor unit 12 and the axial upper end portion of the second motor unit 22 may face the axial end surface of the straightening vane 3 in the axial direction with a gap.

<2-2. Second modification>
In the above-described embodiment and the first modification, the first opening 13a is provided in the first housing 13. Similarly, the second opening 23a may be provided in the second housing 23. FIG. 9 is a perspective view of the series axial flow fan 102 according to the second modification.

The second opening 23a is provided at the upper end portion in the axial direction of the second housing 23, and is recessed downward in the axial direction. The second opening 23a is provided at the same circumferential position as the first opening 13a. In the following, the first opening 13a and the second opening 23a are collectively referred to as "openings 13a, 23a".

The second opening 23a penetrates the second housing 23 in the radial direction, and particularly penetrates a part of the second cylinder portion 231 and a part of the second flange portion 232 in the radial direction. At the second opening 23a, the radial outer end surface of the straightening vane 3 is exposed to the outside of the series axial flow fan 102. Further, the radial outer end portion of the straightening vane 3 is at the same position as the second opening 23a, or is radially inside the second opening 23a.

The serial axial flow fan 102 may be provided with a second opening 23a together with the first opening 13a, or may be provided with a second opening 23a in place of the first opening 13a. When the second opening 23a is provided together with the first opening 13a, the second opening 23a is preferably provided at the same circumferential position as the first opening 13a. As described above, in the present disclosure, in the connecting portion 100a, at least one of the first housing 13 and the second housing 23, the housing 13 and 23, has an opening that penetrates the at least one housing 13 and 23 in the radial direction. Parts 13a and 23a are provided.

Here, in FIGS. 4A to 4C, the first opening 13a is covered with the band-shaped member 4. Similarly, the second opening 23a may be covered with the band-shaped member 4. As described above, in the present disclosure, the band-shaped member 4 covers the openings 13a and 23a. In this way, the band-shaped member 4 can suppress or prevent air leakage at the openings 13a and 23a of the connecting portion 100a. Therefore, the pressure-air volume characteristic of the series axial flow fan 102 can be improved. Further, it is possible to suppress or prevent the generation of noise due to air leakage.

More specifically, when there are a plurality of openings 13a and 23a, the band-shaped member 4 may cover all the openings 13a and 23a as in FIG. 4A. In this way, the band-shaped member 4 can suppress or prevent air leakage at all the openings 13a and 23a of the connecting portion 100a.

Alternatively, when there are a plurality of openings 13a and 23a, the strip-shaped member 4 may cover some of the openings 13a and 23a, as in FIG. 4B. By doing so, since only a part of the openings 13a and 23a is covered with the band-shaped member 4, the band-shaped member 4 can be saved. For example, when a plurality of series axial flow fans 102 are installed so that the openings 13a and 23a are adjacent to each other, the openings 13a and 23a suppress or suppress air leakage even if they are not covered with the band-shaped member 4. It is especially effective because it can be prevented.

Alternatively, as in FIG. 4C, the strip-shaped member 4 may be wound around the entire circumference in the circumferential direction on the radial outer surface of the connecting portion 100a. Then, the band-shaped member 4 may cover all the openings 13a and 23a. This facilitates the work of providing the strip-shaped member 4. Further, since the band-shaped member 4 covers all the openings 13a and 23a, it is possible to more reliably prevent air leakage at the openings 13a and 23a. In addition, since the number of tape pasting steps is reduced, the tape pasting work becomes easy.

<2-3. Third variant>
In the above-described embodiment, the first modification, and the second modification, the housings 13 and 23 are provided with openings 13a and 23a. However, the present invention is not limited to these examples, and the openings 13a and 23a may not be provided in the housings 13 and 23.

FIG. 10 is a perspective view of the series axial flow fan 103 according to the third modification. Further, FIG. 11 is a cross-sectional view of the series axial flow fan 103 along the alternate long and short dash line EE of FIG. Note that FIG. 10 shows a cross-sectional structure when the series axial flow fan 103 is cut on a virtual plane including the central axis CA. FIG. 11 shows a cross-sectional structure in which the series axial flow fan 103 is cut in a virtual plane perpendicular to the axial direction.

In the third modification, the openings 13a and 23a are not provided in the housings 13 and 23. On the other hand, as shown in FIGS. 10 and 11, the first housing 13 further has a first wall portion 134. The first wall portion 134 is provided between the first leg portions 132b adjacent to each other in the circumferential direction. That is, one end of the first wall portion 134 in the circumferential direction is connected to one of the first leg portions 132b adjacent to each other in the circumferential direction. The other end of the first wall portion 134 in the circumferential direction is connected to the other of the first leg portions 132b adjacent to each other in the circumferential direction.

Further, the first wall portion 134 is provided at the lower end portion in the axial direction of the first housing 13, and projects downward in the axial direction from the outer end portion in the axial direction of the lower end surface in the axial direction of the first housing 13. Then, the first wall portion 134 comes into contact with the axial upper end surface of the second housing 23. More specifically, in the third modification, the first wall portion 134 is provided on the axial lower end surface of the first cylinder portion 131 and the axial lower end surface of the first flange portion 132. That is, a part of the first wall portion 134 projects downward in the axial direction from the radial outer end portion of the axial lower end surface of the first cylinder portion 131, and abuts on the axial upper end portion of the second cylinder portion. Further, the remaining part of the first wall portion 134 protrudes downward in the axial direction from the radial outer end portion of the axial lower end surface of the first flange portion 132, and hits the axial upper end portion of the second flange portion 232. Contact. As a result, the radial outer surface of the straightening vane 3 is not exposed to the outside of the first housing 13, but is between the first cylinder portion 131 and the second cylinder portion 231 in the axial direction, and from the first wall portion 134. The straightening vane 3 can be accommodated in the space inside in the radial direction. Further, as shown in FIG. 11, for example, the radial outer end portion of the straightening vane 3 abuts on the radial inner surface of at least a part of the first wall portion 134, so that the straightening vane 3 in the direction perpendicular to the axial direction Can be positioned.

As in the case of the first wall portion 134 of FIGS. 10 and 11, the second housing 23 may have the second wall portion 234 as shown in FIG. 12. FIG. 12 is a cross-sectional view showing an example of the second wall portion 234. Note that FIG. 12 corresponds to, for example, a cross-sectional structure along the alternate long and short dash line FF of FIG.

The second wall portion 234 is provided at the upper end portion in the axial direction of the second housing 23. Then, the second wall portion 234 protrudes upward in the axial direction from the radial outer end portion of the axial upper end surface of the second housing 23 and abuts on the axial lower end surface of the first housing 13. For example, the second wall portion 234 abuts on the axial lower end surface of the first cylinder portion 131 and the axial lower end surface of the first flange portion 132. Alternatively, the second wall portion 234 abuts on the axial lower end portion of the first wall portion 134 provided in the first housing 13 as shown in FIG. In the following, the generic name of the first wall portion 134 and the second wall portion 234 will be referred to as "wall portion 134, 234".

As described above, in the present disclosure, at least one of the housings 13 and 23 is located at the axial end portion of the first housing 13 and the second housing 23 on the connecting portion 100a side. Wall portions 134, 234 that project axially from the radial outer end are provided. The wall portions 134 and 234 are provided between the leg portions 132b and 232b adjacent to each other in the circumferential direction. In this way, one of the wall portions 134 and 234 provided at one axial end of the housings 13 and 23 is a wall provided at the other of the housings 13 and 23 or the other axial end of the housings 13 and 23. It abuts on the other side of the portions 134 and 234. As a result, the radial outer surface of the straightening vane 3 is not exposed to the outside of the housings 13 and 23, and is between the first cylinder portion 131 and the second cylinder portion 231 in the axial direction and from the wall portions 134 and 234. The straightening vane 3 can be accommodated in the space inside in the radial direction. Therefore, the leakage of the airflow in the connecting portion 100a can be further suppressed. Therefore, the pressure-air volume characteristic of the series axial flow fan 103 can be improved. Further, it is possible to suppress or prevent the generation of noise due to air leakage. Further, for example, as shown in FIG. 11, the radial outer end portion of the straightening vane 3 abuts on the radial inner surface of at least a part of the wall portions 134 and 234, so that the straightening vane 3 in the direction perpendicular to the axial direction Can be positioned. Therefore, the assembly work of the series-type axial flow fan 103 becomes easy, and the assembly tolerance of the series-type axial flow fan 103 can be reduced.

<3. Others>
In the present disclosure, exemplary embodiments have been described. The scope of the present invention is not limited to the present disclosure. The present disclosure can be carried out with various modifications without departing from the gist of the present invention. In addition, the matters described in the present disclosure can be arbitrarily combined as long as they do not cause a contradiction.

The present disclosure is useful for devices in which two axial flow fans 1 and 2 are connected in series.

100, 101, 102, 103 ... series axial flow fan, 100a ... connecting part, 1 ... first axial flow fan, 11 ... first impeller, 111 ... first blade, 12 ... 1st motor part, 13 ... 1st housing, 13a ... 1st opening, 131 ... 1st cylinder part, 131a ... 1st recess, 132 ... 1st flange part , 132a ... 1st flat surface portion, 132a ... 1st leg portion 133 ... 1st rib, 134 ... 1st wall portion, 14 ... 1st lead wire, 2 ... 2-axis flow fan, 21 ... 2nd impeller, 211 ... 2nd blade, 22 ... 2nd motor section, 23 ... 2nd housing, 23a ... 2nd opening, 231 ... 2nd cylinder part, 231a ... 2nd concave part, 232 ... 2nd flange part, 232a ... 2nd flat part part, 233 ... 2nd rib, 234 ... 2nd wall part, 24 ... 2nd lead wire, 3 ... rectifying plate, 3a ... hollow cell, 31 ... partition wall, 4 ... strip-shaped member, CA ... central axis

Claims (15)

With the 1st axis flow fan,
The second axial flow fan connected in series with the first axial flow fan and
A straightening vane that is partitioned by a grid-shaped partition wall and has a plurality of hollow cells that penetrate in the axial direction uniformly arranged two-dimensionally up to the outer edge.
Equipped with
The first axial flow fan is
A first impeller having a first blade that can rotate about a central axis extending in the vertical direction,
A first motor unit that drives the first impeller to rotate the first blade, and
A first housing having a cylindrical shape extending in the axial direction and having a first tubular portion for accommodating the first impeller and the first motor portion.
The first lead wire extending from the first motor unit and
Have,
The second axial flow fan is
A second impeller having a second blade that can rotate about the central axis,
A second motor unit that drives the second impeller to rotate the second blade, and
A second housing having a cylindrical shape extending in the axial direction and having a second tubular portion for accommodating the second impeller and the second motor portion.
The second lead wire extending from the second motor unit and
Have,
The axial lower end of the first housing and the axial upper end of the second housing are directly connected to each other.
The straightening vane is provided at a connecting portion between the first housing and the second housing.
The lower end portion in the axial direction of the first cylinder portion is axially opposed to the upper end portion in the axial direction of the second cylinder portion via the straightening vane.
The axial end surface of at least one of the axial lower end surface of the first cylinder portion and the axial upper end surface of the second cylinder portion has a recess recessed on the side opposite to the axial connection portion. Provided,
At least one of the first lead wire and the second lead wire is accommodated in the recess.
A series-type axial flow fan in which at least a part of the recess is axially overlapped with a part of the straightening vane. The series type according to claim 1, wherein the radial outer end of the rectifying plate is the same as the radial outer end of the recess or radially inside the radial outer end of the recess when viewed from the axial direction. Axial flow fan. The first housing has a first flange portion extending radially outward from an axial end portion on the connecting portion side of the first cylinder portion.
The second housing has a second flange portion that extends radially outward from the axial end portion of the second cylinder portion on the connecting portion side.
According to claim 1 or 2, the axial end surface of at least one of the first flange portion and the second flange portion on the connecting portion side is provided with a leg portion protruding in the axial direction. The series axial flow fan described. The series-type axial flow fan according to claim 3, wherein the legs are provided radially outside the recesses when viewed from the axial direction. The serial axial flow fan according to claim 3 or 4, wherein the axial length of the leg portion is equal to or less than the axial length of the straightening vane. There are a plurality of flange portions on which the legs are provided, and each of them is provided in the circumferential direction.
At the axial end of at least one of the first housing and the second housing on the connecting portion side, a wall portion protruding axially from the radial outer end of the at least one housing is provided. Be,
The series-type axial flow fan according to any one of claims 3 to 5, wherein the wall portion is provided between the legs adjacent to each other in the circumferential direction. The serial axial flow fan according to any one of claims 3 to 6, wherein the first flange portion and the second flange portion are provided with a flat surface portion that abuts on the axial end surface of the straightening vane. .. The straightening vane has a honeycomb structure in which the hollow cells having a hexagonal shape when viewed from the axial direction are two-dimensionally arranged.
The width between the two sides of the hexagonal hollow cell extending in parallel and facing each other is larger than the radial width of the axial end portion of the first cylinder portion and the second cylinder portion on the connecting portion side. The series axial flow fan according to any one of claims 1 to 7. The series-type axial flow fan according to claim 8, wherein the hollow cell of the straightening vane having the honeycomb structure has an opening ratio of 90% or more. The first housing further has a first rib that supports the first motor portion at the radial inner end and the radial outer end is connected to the first cylinder.
The second housing further has a second rib that supports the second motor portion at the radial inner end and connects the radial outer end to the second cylinder.
At least one of the first rib and the second rib has a gap with the straightening vane and faces in the axial direction.
The serial axial flow according to claim 8 or 9, wherein the minimum axial width of the gap is narrower than the width between the two sides of the hexagonal hollow cell of the straightening vane having the honeycomb structure. fan. The serial axial flow fan according to claim 10, wherein the width of the portion of the at least one rib facing the straightening vane in the axial direction is equal to or less than the width between the two sides of the hexagonal hollow cell. The axial width of the gap between the radial inner end of at least one of the ribs and the straightening vane is smaller than the width between the two sides of the hexagonal hollow cell.
Claim 10 or claim 11 that the axial width of the gap between the radial outer end of at least one of the ribs and the straightening vane is larger than the width between the two sides of the hexagonal hollow cell. The series axial flow fan described in. Further, a band-shaped member provided on the radial outer surface of the connecting portion is provided.
In the connecting portion, at least one of the first housing and the second housing is provided with an opening that radially penetrates the at least one housing.
The series-type axial flow fan according to any one of claims 1 to 12, wherein the strip-shaped member covers the opening. There are a plurality of the openings,
The series-type axial flow fan according to claim 13, wherein the band-shaped member covers a part of the openings. The series-type axial flow fan according to claim 13, wherein the strip-shaped member is wound around the entire circumferential direction on the radial outer surface of the connecting portion and covers the entire opening.

Images