Fan casing and fan apparatus

A fan casing includes: an air duct communicating with an air inlet and outlet; a frame body forming an outer peripheral surface of the air duct; a hub portion forming an inner peripheral surface of the air duct on the outlet side; and a stator blade portion provided in the air duct, the stator blade portion coupling the frame body to the hub portion. The hub portion includes a cylindrical-shaped cylindrical portion and a tapered portion provided next to the cylindrical portion and provided in such a manner as to increase the width of the air duct toward the outlet. The stator blade portion couples the cylindrical portion to the frame body.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Japanese Patent Application No. 2015-002176 filed with the Japan Patent Office on Jan. 8, 2015, the entire content of which is hereby incorporated by reference.

BACKGROUND

1. Technical Field

An embodiment of the present disclosure relates to a fan casing and a fan apparatus including the fan casing.

2. Description of the Related Art

In recent years, what is called an axial fan apparatus such as described in JP-A-05-133398 has been widely used as a cooling fan of an electronic apparatus such as a server. The axial fan apparatus rotates rotor blade portions pivotally supported by a motor in an air duct of a fan casing to blow air through the air duct.

SUMMARY

A fan casing includes: an air duct communicating with an air inlet and outlet; a frame body forming an outer peripheral surface of the air duct; a hub portion forming an inner peripheral surface of the air duct on the outlet side; and a stator blade portion provided in the air duct, the stator blade portion coupling the frame body to the hub portion. The hub portion includes a cylindrical-shaped cylindrical portion and a tapered portion provided next o the cylindrical portion and provided in such a manner as to increase the width of the air duct toward the outlet. The stator blade portion couples the cylindrical portion to the frame body.

DESCRIPTION OF EMBODIMENT

Improving performance of the air flow has been proposed in a known fan apparatus. There is a case where the size of an air duct of a fan casing is restricted by a drive component such as a motor, and the performance of the motor or the like is constant. In this case, it is not easy to improve the performance of the air flow beyond the restrictions on the size of the air duct of the fan casing and the like.

In order to improve the performance of the air flow of the fan apparatus here, the static pressure in the air duct of the fan casing is also considered. Generally, the fan apparatus has air flow-static pressure characteristics where the static pressure is reduced with increasing air flow. Such a fan apparatus is required to increase the air flow at a static pressure of approximately zero and improve the performance of the air flow of when the static pressure is acting.

One object of the present disclosure is to provide a fan casing and a fan apparatus that have high performance of the air flow.

A fan casing according to one embodiment of the present disclosure (the fan casing) includes: an air duct communicating with an air inlet and outlet; a frame body forming an outer peripheral surface of the air duct; a hub portion forming an inner peripheral surface of the air duct on the outlet side; and a stator blade portion provided in the air duct, the stator blade portion coupling the frame body to the hub portion. The hub portion includes a cylindrical-shaped cylindrical portion and a tapered portion provided next to the cylindrical portion and provided in such a manner as to increase the width of the air duct toward the outlet. The stator blade portion couples the cylindrical portion to the frame body.

The tapered portion may be inclined toward a central axis of the cylindrical portion, or may have an arc shape.

The stator blade portion may extend toward the outlet beyond a coupled part between the stator blade portion and the cylindrical portion, and may be placed around the tapered portion, spaced from the tapered portion.

A fan apparatus according to one embodiment of the present disclosure includes: the fan casing; a motor; and a rotor blade portion pivotally supported by the motor, and rotated by drive of the motor to blow air through the air duct.

According to the embodiment of the preset disclosure, the performance of the air flow against static pressure can be improved.

One embodiment of the present disclosure is described hereinafter.FIG. 1is a perspective view of a fan apparatus50being an axial fan.FIG. 2is a cross-sectional explanatory view illustrating across section A inFIG. 1.

The fan apparatus50at least includes a motor20, rotor blade portions30for blowing air, and a fan casing10surrounding the motor20and the rotor blade portions30.

The fan casing10includes an air duct40. The air duct40communicates with an air inlet41and outlet42. The fan casing10includes a frame body1, a hub portion2, and eight stator blade portions3. The frame body1forms outer peripheral surface of the air duct40. The hub portion2forms an inner peripheral surface of the air duct40on the outlet side. The stator blade portions3couple the frame body1to the hub portion2.

In the embodiment, the fan casing10includes eight stator blade portions3. However, the number of the stator blade portions3is not limited to eight, and may be equal to or more than mine or equal to or less than seven.

The hub portion2is configured including a cylindrical-shaped cylindrical portion2bon the inlet41side while including a tapered portion2aon the outlet42side.

The tapered portion2ais coupled to (is provided next to) the cylindrical portion2b. As illustrated inFIG. 2, the tapered portion2ais provided in such a manner as to increase the width of the air duct40toward the outlet42. In other words, the tapered portion2ais configured in such a manner as to be inclined toward a central axis of the hub portion2.

In the embodiment, the tapered portion2ahas a linear slope. Instead of this, the tapered portion2amay be configured having a curved slope or an arc shape.

The stator blade portions3are configured in such a manner as to be coupled to the frame body1at the cylindrical portion2bon the inlet41side. In other words, the stator blade portions3couple the cylindrical portion2bof the hub portion2to the frame body1. The stator blade portions3are not coupled to the tapered portion2aon the outlet42side. In other words, the stator blade portions3are configured in such a manner as to avoid coupling to the tapered portion2aof the hub portion2. The stator blade portions3extend toward the outlet42beyond the parts coupled to the cylindrical portion2b, and are placed around the tapered portion2a, spaced from the tapered portion2a.

Moreover, the cross section A illustrated inFIG. 1is perpendicular to the central axis of the hub portion2and the rotation direction of the rotor blade portion30. The stator blade portion3has a shape inclined in a curved fashion (for example, an arc shape) with respect to the cross section A.

In the embodiment, the stator blade portion3is inclined in a curved fashion with respect to the cross section A. Instead of this, the stator blade portion3may be formed in such a manner as to be linearly inclined with respect to the cross section A. Alternatively, the stator blade portion3may be formed in such a manner as to have a linear shape (for example, a flat-plate shape) parallel to the cross section A. Furthermore, the stator blade portion3may be formed in such a manner as to have a spiral shape with respect to the central axis of the hub portion2. Especially, the shape of the stator blade portion3can be changed in design in accordance with the shape of the rotor blade portion30, as appropriate.

Moreover, as illustrated inFIG. 2, a stator blade upper surface portion3U of the stator blade portion3on the outlet42side is placed at a position lower by approximately several millimeters than a hub upper surface portion2U of the hub portion2on the outlet42side. In the embodiment, the stator blade upper surface portion3U is placed at the position lower by approximately several millimeters than the hub upper surface portion2U. Instead of this, the stator blade upper surface portion3U and the hub upper surface portion2U may be placed at positions at substantially the same height.

When the tapered portion is provided to the hub portion, the stator blade portions owe typically coupled also to the tapered portion to pull out a mold from the inlet side. Therefore, it is difficult to cause the stator blade portions and the tapered portion to be spaced apart.

According to the shape of the fan casing10in the embodiment, the stator blade portions3can be spaced from the tapered portion2aby removing all parts that cannot be molded. The removal of all the parts that cannot be molded enables the vertical pull-out of two molds, a first mold on the inlet41side and a second mold on the outlet42side. As a result, the fan casing10in the embodiment can be produced very easily.

As illustrated inFIG. 2, the motor20is provided inside the hub portion2. The motor20(the fan apparatus50) includes a circuit board that controls the motor20, bearings22uand22d, a stat23, a coil24wound around the stator23, and a rotor25.

In the embodiment, the fan apparatus50is configured including the circuit board21. Instead of this, the fan apparatus50may not include the circuit board21.

The rotor25is connected to the rotatable rotor blade portions30. When the motor20is driven, the rotor blade portions30are rotated to take in air from the inlet41side, The air taken in is blown toward the outlet42. In other words, the motor20supports the rotor blade portions30pivotally. The motor20is driven to rotate the rotor blade portions30. Air is then blown through the air duct40.

The number of the rotor blade portions30is seven that is less by one than the eight stator blade portions3. The number of the rotor blade portions30is not limited to seven, but may be equal to or more than eight, or equal to or less than six. However, the number of the rotor blade portions30is desired to be less than the number of the stator blade portions3.

Next, the relationship between air flow and static pressure in the fan apparatus50according to the embodiment is described.

FIG. 3is a diagram illustrating the relationships between air flow and static pressure in the fan apparatus50according to the present embodiment and a known fan apparatus500(seeFIG. 4). In the relationship diagram between air flow and static pressure illustrated inFIG. 3, the vertical axis indicates static pressure, and the horizontal axis indicates air flow. Furthermore, a solid line indicates air flow-static pressure characteristics of the fan apparatus50in the embodiment. A dotted line indicates air flow-static pressure characteristics of the known fan apparatus500.

The known fan apparatus500is briefly described usingFIGS. 4 and 5.FIG. 4is a perspective view of the known fan apparatus500.FIG. 5is a cross-sectional explanatory view illustrating across section B inFIG. 4. The same reference numerals as those inFIGS. 1 and 2are assigned to the same portions as those of the fan apparatus50of the embodiment. Their descriptions are omitted.

The known fan apparatus500at least includes the motor20, the rotor blade portions30, and a fan casing100surrounding the motor20and the rotor blade portions30. Moreover, the known fan casing100includes a frame body101, a hub portion102, and eight stator blade portions103that couple the frame body101to the hub portion102.

In the known fan apparatus500, the hub portion2has a cylindrical shape and does not have a tapered portion on the outlet42side unlike the fan apparatus50according to the embodiment.

Thus, in the known fan apparatus500, the hub portion102is formed such that an entire side surface of the hub portion102is perpendicular to upper surface of the hub portion102, as illustrated inFIG. 5. As is clear from a comparison ofFIGS. 2 and 5, a substantially triangular space in cross-sectional view, which has two sides, the tapered portion2aand a stator blade cross section3a, and is illustrated inFIG. 2, is not formed in the known fan apparatus500.

When the known fan apparatus500such as described above is compared with the fan apparatus50of the embodiment, it can be seen from the illustration ofFIG. 3that the fan apparatus50of the embodiment has higher performance of the air flow against static pressure. Especially, there is a clear difference in maximum air flow. In the fan apparatus50of the embodiment, the maximum air flow is improved approximately 10% as compared to the known fan apparatus500.

In this manner, the fan apparatus50of the embodiment has higher performance of the air flow against static pressure than the known fan apparatus500, One of the reasons is that the hub portion2includes the tapered portion2aand accordingly, it is possible to ensure a large width of the air duct40on the outlet42side and to direct the flow of the air blown from the rotor blade portions30toward the center.

Furthermore, in the fan apparatus50of the embodiment, the height of the stator blade upper surface portion3U of the stator blade portion3is placed close to the height of the hub upper surface portion2U of the hub portion2. Consequently, it is possible to rectify the air blown from the rotor blade portions30. This is also the reason that the fan apparatus50of the embodiment has higher performance of the air flow against static pressure than the known fan apparatus500.

Moreover, as described above, the fan apparatus50of the embodiment has the substantially triangular space in cross-sectional view, which has two sides, the tapered portion2aand the stator blade cross section3a, as illustrated inFIG. 2, Here, if the stator blade portion3is coupled to the tapered portion2a, the air flow can be increased more than the known fan apparatus. However, a vortex and the like may occur at the coupled part between the stator blade portion3and the tapered portion2a. Therefore, the flow of air may be inhibited to reduce the performance of the air flow against static pressure.

According to the fan apparatus50of the embodiment, the substantially triangular space having two sides, the tapered portion2aand the stator blade cross section3a, is formed. Therefore, a vortex and the like hardly occur at the coupled part between the stator blade portion3and the tapered portion2a. As a result, the fan apparatus50can improve the performance of the air flow against static pressure efficiently.

As described above, the fan apparatus50of the embodiment can improve the performance of the air flow against static pressure and obtain suitable air flow-static pressure characteristics.

In the fan apparatus50and the fan casing10of the embodiment, the stator blade portions3are not coupled to the tapered portion2a, and are placed around the tapered portion2a, spaced from the tapered portion2a. Instead of this, the stator blade portions3may be configured in such a manner as to be coupled to the tapered portion2aand also be placed around the tapered portion2a. Also in this case, a large width of the air duct40on the outlet42side can be ensured by the tapered portion2a. Therefore, the air blown from the rotor blade portions30can be directed toward the center. As a result, the performance of the air flow can be improved.

Furthermore, in the fan apparatus50and the fan casing10of the embodiment, the stator blade portions3extend toward the outlet42beyond the coupled parts between the static blade portions3and the cylindrical portion2b. Furthermore, the static blade portions3are placed around the tapered portion2a, spaced from the tapered portion2a. Instead of this, the stator blade portions3may not extend toward the outlet42beyond the coupled parts between the static blade portions3and the cylindrical portion2b. In other words, the static blade portions3may not be placed around the tapered portion2a. Also in this case, a large width of the air duct40on the outlet42side can be ensured by the tapered portion2a. Therefore, the air blown from the rotor blade portions30can be directed toward the center. As a result, the performance of the air flow can be improved.

In the fan apparatus50, the substantially triangular portion having the two sides, the tapered portion2aand the stator blade cross section3a, may be formed as illustrated inFIG. 2.

Embodiments of the present disclosure may be the following first and second fan casings, and first fan apparatus.

The first fan casing is a fan casing having an air duct communicating with an air inlet and outlet, and includes a frame body forming an outer peripheral surface of the air duct, a hub portion forming an inner peripheral surface of the air duct on the outlet side, and a stator blade portion provided in the air duct, the stator blade portion coupling the frame body to the hub portion. The hub portion has a cylindrical-shaped cylindrical portion, and a tapered portion coupled to the cylindrical portion and inclined toward a central axis of the cylindrical portion, or formed into an arc shape, to increase the width of the air duct toward the outlet. The stator blade portion is coupled to the frame body at the cylindrical portion.

In the second fan casing according to the first casing, the static blade portion extends toward the outlet beyond a part coupled to the cylindrical portion, and is located around the tapered portion, spaced from the tapered portion.

The first fan apparatus includes a fan casing having an air duct communicating with an air inlet and outlet, a motor, and a rotor blade portion pivotally supported by the motor, the first fan apparatus being configured to blow air through the air duct by the rotor blade portion being rotated by drive of the motor. The fan casing has a frame body forming an outer peripheral surface of the air duct, a hub portion forming an inner peripheral surface of the air duct on the outlet side, and a stator blade portion provided in the air duct to couple the frame body to the hub portion. The hub portion has a cylindrical-shaped cylindrical portion, and a tapered portion coupled to the cylindrical portion and inclined toward a central axis of the cylindrical portion, or formed into an arc shape, to increase the width of the air duct toward the outlet. The stator blade portion is coupled to the frame body at the cylindrical portion.

The first and second fan casings and the first fan apparatus can improve the performance of the air flow against static pressure.