JP2010185443A - Serial axial flow fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a serial axial flow fan comprising three or more axial flow fans being connected in series, which can solve the problem that the rotating components of the air stream is too increased to efficiently improve the static pressure. <P>SOLUTION: In the serial axial flow fan 1 comprising three axial flow fans 2, 3, 4 being connected, two axial flow fans of the three axial flow fans 2, 3, 4 rotate in the opposite directions, and the stator vane 25 is provided, or stator vanes are provided to every two axial fans at their exhaust side. In the serial axial flow fan comprising four axial flow fans being connected, two set of two axial fans rotating in opposite directions being combined are combined. By these configurations, the rotating components of the air flow delivered by the serial axial flow fan 1 is decreased, and the axial components thereof is increased to improve the static pressure of the air stream to be delivered. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a series axial fan in which three or more axial fans are connected in series.

Conventionally, cooling fans for cooling electronic components have been provided inside the housings of various electronic devices, resulting from an increase in the amount of heat generated due to higher performance of electronic components, miniaturization of the housing, etc. As the arrangement density increases, it is required to improve the static pressure-air volume characteristics of the cooling fan. In recent years, a series-type axial fan in which a plurality of fans are connected in series has been proposed as a cooling fan that secures a sufficient static pressure and air volume.
U.S. Patent Application Publication No. 2008/0124232 discloses an assembly in which three axial fans are connected in series.
Japanese Patent Laying-Open No. 2005-16323 also discloses a serial connection module having a structure in which three fan units are arranged in series on a coupling plate.
US Patent Application Publication No. 2008/0124232 JP 2005-16323 A

  By the way, in a series axial fan in which three or more axial fans are connected in series, compared to a single axial fan or a series axial fan in which two axial fans are connected, the airflow to be sent out can be reduced. Increases static pressure. However, in a series axial fan having a structure in which identical axial fans having a simple structure are connected in series, the swirl component of the air flow becomes large, and the static pressure cannot be improved efficiently.

  An object of the present invention is to improve the static pressure by increasing the axial component of air delivered by a serial axial fan.

  In the first aspect of the present invention, the in-line axial flow fan includes a first impeller positioned closest to the exhaust side, and the first impeller is attached to a rotor portion and rotates the first impeller about a central axis. A first motor unit, a second impeller positioned second from the exhaust side, a second motor unit attached to the rotor unit and rotating the second impeller about the central axis, and an exhaust A third impeller that is located third from the side, and a third motor part that is attached to the rotor part and that rotates the third impeller about the central axis in a direction opposite to the second impeller. A plurality of stationary blades positioned on the exhaust side of the first impeller and extending in a substantially radial direction centered on the central axis; and a cylindrical shape surrounding the outer periphery of the first impeller, the second impeller, and the third impeller With the wind tunnel That.

  In a second aspect of the present invention, the in-line axial fan includes a first impeller located closest to the exhaust side, and the first impeller is attached to a rotor portion and rotates the first impeller about a central axis. A first motor unit, a second impeller positioned second from the exhaust side, and the second impeller is attached to the rotor unit, and the second impeller is disposed in a direction opposite to the first impeller about the central axis A second motor section that rotates, a third impeller that is positioned third from the exhaust side, and a third motor section that is attached to the rotor section and rotates the third impeller about the central axis. A plurality of stationary blades positioned between the second impeller and the third impeller and extending in a substantially radial direction centered on the central axis; the first impeller, the second impeller, and the third impeller; Tube that surrounds the outer circumference And a wind tunnel part.

  In a third aspect of the present invention, the in-line axial flow fan includes a first impeller positioned closest to the exhaust side, and the first impeller is attached to a rotor portion and rotates the first impeller about a central axis. A first motor unit, a second impeller positioned second from the exhaust side, a second motor unit attached to the rotor unit and rotating the second impeller about the central axis, and an exhaust A third impeller located third from the side, a third motor part attached to the rotor part and rotating the third impeller around the central axis, and an exhaust side of the first impeller A plurality of stationary blades that are positioned and extend in a substantially radial direction around the central axis, and a plurality of other stationary blades that are positioned between the first impeller and the second impeller and extend in the substantially radial direction And the first impeller, the first impeller And a tubular air duct surrounding the impeller and the outer periphery of the third impeller.

  In a fourth aspect of the present invention, the in-line axial fan has a first impeller located closest to the exhaust side, and the first impeller is attached to a rotor portion and rotates the first impeller about a central axis. A first motor unit, a second impeller positioned second from the exhaust side, and the second impeller is attached to the rotor unit, and the second impeller is disposed in a direction opposite to the first impeller about the central axis A second motor section that rotates, a third impeller that is positioned third from the exhaust side, and a third motor section that is attached to the rotor section and rotates the third impeller about the central axis. A fourth impeller positioned fourth from the exhaust side, and a fourth motor attached to the rotor portion and rotating the fourth impeller about the central axis in a direction opposite to the third impeller And Comprising serial first impeller, the second impeller, and a cylindrical air channel portion surrounding the outer periphery of the third impeller and the fourth impeller.

ADVANTAGE OF THE INVENTION According to this invention, the static pressure of the air sent out from the series type axial flow fan which connected the 3 or more axial flow fan can be improved.
The first and second aspects of the present invention are series-type axial fans in which three axial fans are connected, and the rotating direction of two of the three axial fans is reversed and the stationary blades are Provided.
The third aspect of the present invention is a series axial fan in which three axial fans are connected, and a stationary blade is provided on each exhaust side of the two axial fans.
A fourth aspect of the present invention is a series axial fan in which four axial fans are connected, and two axial fans whose rotation directions are opposite to each other are combined, and two of them are combined.
With such a configuration, the swirl component in the series axial fan is reduced, and the static pressure of the delivered air is improved.

FIG. 1 is a cross-sectional view showing an inline axial fan according to the first embodiment. FIG. 2 is a bottom view of the first axial fan. FIG. 3 is a bottom view of the second axial fan. FIG. 4 is a bottom view of the third axial fan. FIG. 5 is a cross-sectional view of an in-line axial fan according to the second embodiment. FIG. 6 is a cross-sectional view of a series axial fan according to the third embodiment. FIG. 7 is a cross-sectional view of a series axial fan according to the fourth embodiment. FIG. 8 is a cross-sectional view of a series axial fan according to another example. FIG. 9 is a bottom view of the stationary blade portion. FIG. 10 is a cross-sectional view of a series axial fan according to still another example.

  FIG. 1 is a longitudinal sectional view showing a serial axial fan 1 according to a first embodiment of the present invention. The serial axial fan 1 is used as a cooling fan for air-cooling electronic equipment such as a server. It is done. The serial axial fan 1 includes a first axial fan 2, a second axial fan 3, and a third axial fan 4. The first axial fan 2 is located on the lower side in FIG. The second axial fan 3 is connected to the upper side of the first axial fan 2 along the central axis J1, and the third axial fan 4 is connected to the upper side of the second axial fan 3 along the central axis J1. It is connected to the. The central axis J1 coincides with the central axes of the first axial fan 2, the second axial fan 3, and the third axial fan 4. The coincidence of the central axes is the same in the following embodiments.

  In the serial axial fan 1, air flows in a direction along the central axis J1 so that air is taken in from the upper side in FIG. 1 and sent out to the lower side. In the following description, in the direction of the central axis J1, the upper side in FIG. 1 on which air is taken in is referred to as “upper side” or “intake side”, and the lower side in FIG. It is called “lower side” or “exhaust side”. The expressions “upper” and “lower” do not necessarily coincide with the upper and lower sides with respect to the direction of gravity.

The first axial fan 2 includes a first impeller 21, a first motor unit 22, a first housing 23, and a plurality of stationary blades 25. The first motor unit 22 generates an air flow by rotating the first impeller 21 around the central axis J1. The first housing 23 is a cylindrical housing that surrounds the outer periphery of the first impeller 21. The plurality of stationary blades 25 are blade-shaped support ribs that are located on the exhaust side of the first impeller 21 and extend in a substantially radial direction with the central axis J1 as the center. The stationary blade 25, the first housing 23, and the base portion 24 of the first motor portion 22 are formed as one member by injection molding resin. The first housing 23 and the base part 24 are connected via the stationary blade 25.
In FIG. 1, for convenience of illustration, the schematic shapes of the blades 211 and the stationary blades 25 of the first impeller 21 are shown on the left and right of the central axis J1. Moreover, the 1st motor part 22 is exaggerated and enlarged, and illustration of the hatching with respect to the cross section of each component is abbreviate | omitted. The second axial fan 3 and the third axial fan 4 are also illustrated in the same manner. The same applies to other sectional views of the following axial fan.

  The first impeller 21 extends from the outer surface of the cup 212 that covers the outside of the first motor portion 22 toward the outside in the radial direction with the center axis J1 as the center. It has a plurality of blades 211 arranged at equal pitches in the circumferential direction around the axis J1. The first motor unit 22 includes a first rotor unit 221 that is a rotating body and a first stator unit 222 that is a fixed body. The first rotor part 221 is positioned above the first stator part 222 along the central axis J1.

  The first rotor portion 221 includes a substantially cylindrical metal yoke 2211 with a center axis J1 as a center, a substantially cylindrical field magnet 2212 fixed to the inside of the yoke 2211, and an upper center of the yoke 2211. A shaft 2213 protruding downward is provided. The first impeller 21 is attached to the first rotor portion 221 so that the cup 212 covers the yoke 2211.

  The first stator portion 222 includes a substantially disc-shaped base portion 24, a substantially cylindrical bearing holding portion 2221 protruding upward from the center of the base portion 24, a stator 2222 attached to the outer periphery of the bearing holding portion 2221, and a stator A circuit board 2223 electrically connected to the stator 2222 is provided on the lower side of 2222. The stator 2222 faces the field magnet 2212 in the radial direction centered on the central axis J1 (hereinafter simply referred to as “radial direction”). A torque about the central axis J1 is generated between the stator 2222 and the field magnet 2212. Inside the bearing holding portion 2221, ball bearings 2224 and 2225 which are bearing mechanisms are provided at the upper and lower portions in the direction of the central axis J1. A shaft 2213 inserted into the bearing holding portion 2221 is rotatably supported by ball bearings 2224 and 2225.

The 2nd axial flow fan 3 has the same structure as what inverted the 1st axial flow fan 2 up and down except for one part shape. The second axial fan 3 includes a second impeller 31, a second motor unit 32, a second housing 33, and a plurality of rod-shaped support ribs 35. The second impeller 31 has a plurality of blades 311 that extend radially outward from the outer surface of the bottomed substantially cylindrical cup 312. The second motor unit 32 rotates the second impeller 31 to generate an air flow in the same direction as the first impeller 21. The second housing 33 has a cylindrical shape surrounding the outer periphery of the second impeller 31, and is connected to the first housing 23 along the central axis J1. The plurality of rod-shaped support ribs 35 connect the base portion 34 of the second motor portion 32 and the second housing 33. The second housing 33, the base portion 34, and the second support rib 35 are formed as one member by resin injection molding.
In the following description, the support rib 35 of the second axial fan 3 is referred to as a “second support rib 35”.

  The second motor unit 32 has substantially the same structure as the first motor unit 22. The second motor part 32 includes a second rotor part 321 that is a rotating body and a second stator part 322 that is a fixed body. The second rotor part 321 is located below the second stator part 322. The second rotor portion 321 includes a bottomed substantially cylindrical yoke 3211, a field magnet 3212 fixed to the inside of the yoke 3211, and a shaft 3213 protruding upward from the center of the yoke 3211. The second impeller 31 is attached to the second rotor portion 321 so that the cup 312 covers the yoke 3211.

  The second stator portion 322 includes a substantially disk-shaped base portion 34, a bearing holding portion 3221 that protrudes downward from the center of the base portion 34, and a field magnet 3212 that is attached to the outer periphery of the bearing holding portion 3221. And a circuit board 3223 disposed above the stator 3222, and a shaft 3213 inserted into the bearing holding portion 3221 is rotatably supported by ball bearings 3224 and 3225.

  The third axial fan 4 has substantially the same structure as that obtained by inverting the second axial fan 3 upside down. The third impeller 41 and the third impeller 41 centered on the central axis J1 are opposite to the second impeller 31. Of the third motor part 42 that generates the air flow in the same direction as the first impeller 21 by rotating in the direction, the cylindrical third housing 43 that surrounds the outer periphery of the third impeller 41, and the third motor part 42 A plurality of rod-shaped support ribs 45 connecting the base portion 44 and the third housing 43 are provided. In the following description, the support rib 45 of the third axial fan 4 is referred to as a “third support rib 45”.

  The third impeller 41 has a plurality of blades 411 extending radially outward from the outer surface of the cup 412, and the third housing 43 is connected to the second housing 33 along the central axis J <b> 1. Moreover, the 3rd housing 43, the base part 44, and the 3rd support rib 45 are formed as one member by injection molding of resin.

  The third motor part 42 includes a third rotor part 421 and a third stator part 422 located below the third rotor part 421. The third rotor portion 421 includes a covered cylindrical yoke 4211, a field magnet 4212 fixed to the inside of the yoke 4211, and a shaft 4213 protruding downward from the center of the yoke 4211 so that the cup 421 covers the yoke 4211. Thus, the third impeller 41 is attached to the third rotor portion 421.

  The third stator portion 422 includes a substantially disc-shaped base portion 44, a bearing holding portion 4221 that protrudes upward at the center of the base portion 44, a stator 4222 that is attached to the outer periphery of the bearing holding portion 4221, and a lower portion of the stator 4222. The circuit board 4223 is provided on the side, and the base part 44 abuts on the base part 34 of the second axial fan 3. In the third motor portion 42, the shaft 4213 inserted into the bearing holding portion 4221 is rotatably supported by ball bearings 4224 and 4225.

  FIG. 2 is a bottom view of the first axial fan 2. The lower end portion 231 of the first housing 23 is substantially square, and the upper end portion (end portion on the intake side) has the same shape. The stationary vanes 25 are inclined with respect to a direction parallel to the central axis J1 and a plane perpendicular to the central axis J1. The radially outer end is located at the central portion 2312 between the two adjacent corner portions 2311 of the first housing 23.

  Further, in the first axial fan 2, a notch 241 is provided in the base portion 24 so that a part of the lower surface of the circuit board 2223 is exposed, and the lower end portion 231 of the first housing 23 is near the upper right corner portion 2311 in FIG. Is provided with a groove 2311a extending from the inner surface to the outer surface. As shown in FIG. 2, the two lead wires 26 connected to the circuit board 2223 are guided in the radial direction to the upper right corner 2311 in FIG. 2 through the notch 241, and the first housing through the groove 2311a. 23 is pulled out to the outside. The lead wire 26 is led to the intake side of the serial axial fan 1 along the outer surfaces of the housings 23, 33, and 43 of the axial fans 2, 3, and 4 shown in FIG. Connected.

  FIG. 3 is a bottom view of the second axial fan 3. Like the first housing 23 shown in FIG. 2, the lower end portion 331 and the upper end portion (end portion on the intake side) of the second housing 33 are substantially square. The The radially inner ends of the four second support ribs 35 are equally spaced on the outer periphery of the base portion 34, and the radially outer ends are between the two adjacent corner portions 3311 of the second housing 33. It is located in the central part 3312. Further, unlike the stationary blade 25 of the first axial fan 2 shown in FIG. 2, the second support rib 35 has a reduced width in the circumferential direction around the central axis J1, and as shown in FIG. The width in the direction parallel to the axis J1 is also reduced.

  At the upper end of the second housing 33 shown in FIG. 3 (the back side in FIG. 3), a groove extending from the inner surface to the outer surface in the vicinity of the upper right corner in FIG. 3 in the same manner as the first housing 23 shown in FIG. The two lead wires 36 connected to the circuit board 3223 (see FIG. 1) are pulled out to the outside of the second housing 33 through the grooves, and the second housing 33 and the third housing 43 (see FIG. 1) are drawn out. ) Is led to the intake side of the serial axial fan 1. In FIG. 3, the lead wire 26 (see FIG. 2) of the first axial fan 2 guided along the outer surface of the second housing 33 along with the lead wire 36 to the intake side of the second housing 33 is omitted. is doing. In the second axial fan 3, only the second support rib 35 and the lead wire 36 exist in the air flow path between the second housing 33 and the second motor unit 32 (see FIG. 1).

  FIG. 4 is a bottom view of the third axial fan 4. The third housing 43 has substantially the same shape as the second housing 33 shown in FIG. 3, and four third support ribs 45 are equally spaced between the inner surface of the third housing 43 and the outer periphery of the base portion 44. Be placed. Unlike the stationary blade 25 of the first axial fan 2 shown in FIG. 2, the third support rib 45 has a reduced width in the circumferential direction around the central axis J1, and as shown in FIG. The width in the direction parallel to is also reduced. The 3rd support rib 45 is located between the 3rd impeller 41 and the 2nd impeller 31 with the 2nd support rib 35, and the 2nd support rib 35 and the 3rd support rib 45 mutually overlap in the direction parallel to central axis J1. . That is, the edge (or surface) of the second support rib 35 facing the third impeller 41 and the edge (or surface) of the third support rib 45 facing the second impeller 31 are substantially parallel to the central axis J1. Overlapping over the entire length.

  As shown in FIG. 4, in the third axial fan 4, as in the first axial fan 3 shown in FIG. A groove 4311a extending from the outer surface to the outer surface is provided. The two lead wires 46 connected to the circuit board 4223 are pulled out to the outside of the third housing 43 through the groove 4311a and guided to the intake side of the third axial fan 4. In FIG. 4, the lead wires 26 and 36 of the other axial fans 2 and 3 guided along the outer surface of the third housing 43 together with the lead wire 46 to the intake side of the third axial fan 4 (FIG. 2). And the illustration of FIG. 3) is omitted. Also in the third axial fan 4, only the third support rib 45 and the lead wire 46 exist in the air flow path between the third housing 43 and the third motor unit 42.

  When the serial axial fan 1 is driven, the third impeller 41 of the third axial fan 4 shown in FIG. 4 is rotated clockwise as indicated by an arrow 93 by the third motor unit 42, and the second axis shown in FIG. The second impeller 31 of the flow fan 3 is rotated counterclockwise as indicated by an arrow 92 by the second motor unit 32 (see FIG. 1), that is, in the direction opposite to the third impeller 41. Thus, the second axial fan 3 and the third axial fan 4 constitute a so-called counter-rotating fan. Further, the first impeller 21 of the first axial fan 2 shown in FIG. 2 is rotated clockwise as indicated by an arrow 91 by the first motor unit 22 (see FIG. 1). As shown in FIG. 1, the air generated by the first impeller 21, the second impeller 31, and the third impeller 41 is a cylindrical shape formed by the first housing 23, the second housing 33, and the third housing 43. The air flows through the wind tunnel 11 from the intake side toward the exhaust side, and is sent from the serial axial fan 1.

  The series axial fan 1 according to the first embodiment has been described above. However, in the series axial fan 1, the second impeller 31 located second from the exhaust side and the third impeller 41 located third. , The flow of air flowing into the first impeller 21 is adjusted in a direction approximately parallel to the central axis J1. Thereby, a part of the swirling component of the air from the third axial fan 4 is converted into the axial component by the second axial fan 3 and the axial component of the air sent to the first impeller 21 is increased. The ventilation efficiency by the 1st impeller 21 located in the most exhaust side is improved. Further, since the swirl component of the air sent from the first impeller 21 is converted into the axial component by the stationary blade 25 located on the exhaust side of the first impeller 21, the axial component is increased. The static pressure of the air sent from 1 is improved, and the air flow rate is also increased.

  In the serial axial fan 1, if the counter-rotating fan is formed by the second axial fan 3 and the third axial fan 4, the first to third impellers 21, 31, 41 are respectively shown in FIG. Or you may rotate in the reverse direction to the direction shown in FIG. Even in this case, the axial component of the air flowing into the first impeller 21 is increased, and the static pressure of the air sent from the serial axial fan 1 is improved.

  As described above, unlike the stationary blade 25, the second support rib 35 of the second axial fan 3 is reduced in width in the direction parallel to the central axis J1 and in the circumferential direction centered on the central axis J1. It does not increase the axial component of air. That is, the second support rib 35 does not substantially function as a stationary blade. Similarly, the third support rib 45 of the third axial fan 4 does not substantially function as a stationary blade. That is, in the serial axial fan 1, a member that functions as a stationary blade is not provided between the first impeller 21 and the second impeller 31. In the in-line axial fan 1, even with such a structure, the second impeller 31 and the third impeller 41 can be rotated in opposite directions to introduce air with less swirl component into the first impeller 21. It has been realized.

  Further, the second support rib 35 and the third support rib 45 overlap in a direction parallel to the central axis J1, in other words, almost the entire length so that the second support rib 35 and the third support rib 45 are along each other. By overlapping (the same applies to the support ribs that overlap each other in the following other embodiments), the support ribs are prevented from obstructing the flow of air.

  Since the stationary blade 25 of the first axial fan 2 is formed as one member with the first housing 23 and the base part 24 of the first motor part 22, the structure of the first axial fan 2 is simplified. Similarly, the second support rib 35 of the second axial fan 3 is formed as one member with the second housing 33 and the base part 34 of the second motor part 32, and the third support rib of the third axial fan 4. Since 45 is formed as one member with the third housing 43 and the base portion 44 of the third motor portion 42, the structures of the second axial fan 3 and the third axial fan 4 are also simplified. The same applies to the stationary blades and the support ribs in the following other embodiments. In the first to third axial fans 2, 3, and 4, the number of lead wires 26, 36, and 46 may be other than two. The same applies to other embodiments.

  The structure of the series axial fan 1 can be applied to a series axial fan having an odd number of axial fans. In this case, in a plurality of axial fans other than the exhaust fan on the most exhaust side, the impellers adjacent to each other rotate in the opposite direction, so that the axial component of the air generated by the odd-numbered axial fans is It is increased by the even-numbered axial fan located below the axial fan, and the axial fan on the most exhaust side increases the axial component of the air by providing a stationary blade on the exhaust side. The impeller of the exhaust fan on the most exhaust side may rotate in the same direction with respect to the impeller of the second axial fan from the exhaust side, or may rotate in the opposite direction.

  FIG. 5 is a longitudinal sectional view showing a series axial fan 1a according to the second embodiment. In the series axial fan 1a, a second axial fan 3a having substantially the same shape as the first axial fan 2 is provided instead of the second axial fan 3 of FIG. The axial fan 3a and the third axial fan 4 are arranged along the central axis J1. The other structure is the same as that of the serial axial fan 1, and hereinafter, the same components will be described with the same reference numerals.

  The first axial fan 2 includes a first impeller 21 having a plurality of blades 211, a first motor unit 22 that rotates the first impeller 21 around the central axis J1, a first housing 23 that surrounds the outer periphery of the first impeller 21, A plurality of stationary blades 25 that are positioned on the exhaust side of the first impeller 21 and extend in a substantially radial direction are provided, and the stationary blade 25, the first housing 23, and the base portion 24 of the first motor portion 22 are formed by a single injection molding of resin. It is formed as a member. In the first motor part 22, the first rotor part 221 to which the first impeller 21 is attached is located above the first stator part 222.

  The second axial fan 3 a includes a second impeller 31 having a plurality of blades 311, a second motor unit 32 that rotates the second impeller 31 in the same direction as the first impeller 21, and a second impeller surrounding the outer periphery of the second impeller 31. The housing 33 includes four stationary blades 35a that are positioned between the second impeller 31 and the first impeller 21 and extend in a substantially radial direction. The second housing 33 and the base portion 34 are connected via the stationary blade 35a, and the stationary blade 35a, the second housing 33, and the base portion 34 of the second motor portion 32 are formed as one member by resin injection molding. . The second impeller 31 may be rotated in the opposite direction to the first impeller 21.

  The third axial fan 4 is substantially the same as the first axial fan 2 except that rod-like support ribs are provided instead of the stationary blades 25 of the first axial fan 2 and has a plurality of blades 411. The third impeller 41, the third motor portion 42 that rotates the third impeller 41 in the direction opposite to the second impeller 31, the third housing 43 that surrounds the outer periphery of the third impeller 41, and the base portion of the third motor portion 42 A plurality of rod-shaped third support ribs 45 that connect 44 and the third housing 43 are provided.

  When the serial axial fan 1a is driven, the air generated by the rotation of the first impeller 21, the second impeller 31, and the third impeller 41 is formed by the first housing 23, the second housing 33, and the third housing 43. It flows in the wind tunnel portion 11 along the central axis J1 and is sent out from the serial axial fan 1a.

  In the serial axial fan 1a, part of the swirl component of the air sent from the second impeller 31 is converted into an axial component by the stationary blade 35a located on the exhaust side of the second impeller 31, and the axial component is changed. A part of the swirl component of the air flowing into the first impeller 21 while being increased and sent out from the first impeller 21 is converted into an axial component by the stationary blade 25 located on the exhaust side of the first impeller 21 in the axial direction. The components are sent from the serial axial fan 1a while being increased.

  Thus, even if the rotation directions of the first impeller 21 and the second impeller 31 are the same, the axial component of the air flowing through the wind tunnel portion 11 is increased by the stationary blades 25 and 35a. The static pressure of the fan 1a is improved. Further, since the first housing 23, the base portion 24, and the stationary blade 25 are formed as one member, and the second housing 33, the base portion 34, and the stationary blade 35a are formed as one member, the first axial flow The structure of the fan 2 and the second axial fan 3a is simplified. In the serial axial fan 1a, even when the rotation directions of the first impeller 21 and the second impeller 31 are different, the axial component of the air flowing into the first impeller 21 is increased by the stationary blade 35a. Thus, in the second embodiment, the rotation direction of the first to third impellers 21, 31, 41 may be any direction, and the rotation direction of the first to third impellers 21, 31, 41 may be any. The axial component of the air flowing through the wind tunnel portion 11 can be increased by the stationary blades 25 and 35a even if the direction of the airflow is set.

  FIG. 6 is a longitudinal sectional view showing a series axial fan 1b according to the third embodiment. The serial axial fan 1b has a structure in which the arrangement of the first axial fan 2, the second axial fan 2, and the third axial fan 3 in the serial axial fan 1 shown in FIG. A counter-rotating fan is configured by the first axial fan 2b and the second axial fan 3b located on the lower side of FIG. 6, and a third axial fan 4b having a plurality of stationary blades 47 is connected to the series axial fan. An axial fan 1b is configured. The other structure is the same as that of the serial axial fan 1, and the same components are denoted by the same reference numerals.

  The first axial fan 2b includes a first impeller 21, a first motor unit 22 that rotates the first impeller 21 around the central axis J1, a first housing 23 that surrounds the outer periphery of the first impeller 21, and a first impeller. A plurality of rod-shaped first support ribs 27 that are located above 21 and connect the first motor unit 22 and the first housing 23 are provided.

  The second axial fan 3 b includes a second impeller 31, a second motor unit 32 that rotates the second impeller 31 around the central axis J <b> 1 in the direction opposite to the first impeller 21, and an outer periphery of the second impeller 31. 2 housing 33 and a plurality of rod-shaped second support ribs 37 that are located below the second impeller 31 and connect the second motor part 32 and the second housing 33. The second support ribs 37 and the first support ribs 27 are located between the first impeller 21 and the second impeller 31 and overlap substantially the entire length in a direction parallel to the central axis J1.

  The third axial fan 4b includes a third impeller 41, a third motor unit 42 that rotates the third impeller 41 in the same direction as the second impeller 31 around the central axis J1, and a third impeller 41 that surrounds the outer periphery of the third impeller 41. A housing 43 and a plurality of stationary blades 47 that are positioned between the third impeller 41 and the second impeller 31 and extend in a substantially radial direction are provided. The stationary blade 47, the third housing 43, and the base portion 44 of the third motor portion 42 are formed as one member by resin injection molding, and the structure of the third axial fan 4b is simplified.

  The third impeller 41 may be rotated in the opposite direction to the second impeller 21. If the first axial fan 2b and the second axial fan 3b constitute a counter rotating fan, the first impeller 41 may be rotated in the first direction. Or the direction of rotation of the third impellers 21, 31, 41 may be any direction.

  When the serial axial fan 1b is driven, the air sent from the third impeller 41 flows into the second impeller 31 while the swirl component is converted into an axial component by the stationary blade 47 and the axial component is increased. Thus, the air blowing efficiency by the second impeller 31 is increased.

  In the serial axial fan 1b, the width of the first support rib 27 and the second support rib 37 in the direction parallel to the central axis J1 and in the circumferential direction around the central axis J1 is larger than the width of the stationary blade 47 in the same direction. The first support rib 27 and the second support rib 37 do not increase the axial component of air as compared with the stationary blade 47. That is, in the serial axial fan 1b, a member that functions as a stationary blade is not provided between the exhaust side of the first impeller 21 and between the first impeller 21 and the second impeller 31. Even in such a structure, since the first axial fan 2b and the second axial fan 3b are counter-rotating fans, a part of the swirling component of the air generated by the rotation of the second impeller 31 is the first. It is converted into an axial component by the 1 impeller 21, and the axial component of the air sent from the serial axial fan 1b is increased to improve the static pressure.

  In the series axial fan 1b, since the axial component of air is increased by the stationary blade 47 and the first impeller 21 and the second impeller 31, the wind tunnel portion formed by the first to third housings 23, 33, 43 is used. The flow of air in 11 is a flow with little turning. Further, in the first axial fan 2b and the second axial fan 3b, the first support rib 27 and the second support rib 37 overlap each other in the direction parallel to the central axis J1, so that these support ribs flow in the air. Hindering is suppressed.

  FIG. 7 is a longitudinal sectional view showing an inline axial fan 1c according to the fourth embodiment. The serial axial fan 1c is a quadruple serial axial fan. The first axial fan 2b and the second axial fan 3b of the series axial fan 1b shown in FIG. 6 have the same structure as that in which two axial fans having the same structure are connected in series. The series axial fan 1c includes a first axial fan 2b located on the lower side of FIG. 7, a second axial fan 3b connected to the first axial fan 2b along the central axis J1, and a second axial fan. A third axial fan 5 connected to the fan 3b along the central axis J1 and a fourth axial fan 6 connected to the third axial fan 5 along the central axis J1 are provided. In the serial axial fan 1c, the first axial fan 2b and the second axial fan 3b are counter-rotating fans, and the third axial fan 5 and the fourth axial fan 6 are counter-inverting fans. Is done.

  The first axial fan 2 b includes a plurality of rod-shaped first support ribs 27 that connect the first motor unit 22 that rotates the first impeller 21 and the first housing 23. The second axial fan 3 b has a plurality of rod-shaped second support ribs 37 that connect the second motor part 32 that rotates the second impeller 31 in the direction opposite to the first impeller 21 and the second housing 33. . The first support rib 27 and the second support rib 37 are located between the first impeller 21 and the second impeller 31. At the same time, they overlap with each other almost in the direction parallel to the central axis J1.

  The third axial fan 5 has a plurality of rod-shaped third support ribs 54 that connect the third motor unit 52 that rotates the third impeller 51 and the third housing 53. The fourth axial fan 6 includes a plurality of rod-like fourth support ribs 64 that connect the fourth motor unit 62 and the fourth housing 63 that rotate the fourth impeller 61 in the direction opposite to the third impeller 51. Have. The third support rib 54 and the fourth support rib 64 are located between the third impeller 51 and the fourth impeller 61. At the same time, the third support rib 54 and the fourth support rib 64 overlap each other over almost the entire length in a direction parallel to the central axis J1.

  With the above arrangement of the support ribs, in the serial axial fan 1c, the support ribs 27, 37, 54, and 64 are prevented from obstructing the air flow.

  When the serial axial fan 1c is driven, the third third impeller 51 and the fourth impeller 51 from the exhaust side are formed in the cylindrical wind tunnel portion 11 formed by the first to fourth housings 23, 33, 53, 63. The direction of rotation with the fourth impeller 61 is reversed. As a result, part of the swirl component of the air is converted into the axial component, and the air sent from the third impeller 51 is sent to the second impeller 31 in a state where the axial component is increased. As a result, the blowing efficiency by the second impeller 31 is increased. Further, the rotation directions of the first impeller 21 closest to the exhaust side and the second impeller 31 second from the exhaust side are reversed. As a result, a part of the swirl component of air is converted into an axial component, the axial component of the air sent from the serial axial fan 1c is increased, and the static pressure is further improved.

  In the series axial fan 1c, the exhaust side of the first impeller 21, between the first impeller 21 and the second impeller 31, and the second impeller 31, depending on the rotation direction of the impellers 21, 31, 51, 61. A portion for obtaining a wind collecting effect is not provided between the third impeller 51 and between the third impeller 51 and the fourth impeller 61 so as to have a blade shape extending in a substantially radial direction. Improvement of static pressure is realized even in a structure in which a stationary blade that increases the axial component of the air is not provided.

  The serial axial fan 1c has a structure in which four axial fans having the same structure are sequentially connected while being inverted. For this reason, since the members which comprise motor parts, such as a stator core, an insulator, and a circuit board, are unified, the manufacturing cost of serial type axial fan 1c can be reduced. Further, the structure of the series axial fan 1c can be applied to a series axial fan in which three or more pairs of counter rotating fans are connected. In this case, odd-numbered support ribs from the exhaust side are arranged on the intake side of the corresponding axial fan, and even-numbered support ribs are arranged on the exhaust side of the corresponding axial fan. As a result, since the odd-numbered and even-numbered support ribs overlap substantially over the entire length in the direction parallel to the central axis, the support ribs are prevented from obstructing the air flow.

  In the fourth embodiment, the first axial fan 2b and the second axial fan 3b form a counter rotating fan. In addition, if the counter-rotating fan is formed by the third axial fan 5 and the fourth axial fan 6, the rotation directions of the impellers 21, 31, 51, 61 may be arbitrary.

  In particular, when it is necessary to reduce the noise during driving of the series axial fan 1c, the second axial fan 3b and the third axial fan 5 are rotated in the same direction to thereby rotate the second axial fan. Noise between 3b and the third axial fan 5 is reduced. Furthermore, the peak frequency of noise between the second axial fan 3b and the third axial fan 5 corresponds to the noise between the first axial fan 2b and the second axial fan 3b, and the third axial fan. Since it deviates from the peak frequency of the noise between 5 and the fourth axial fan 6, it is possible to prevent the noise from concentrating on a specific frequency.

Although the first to fourth embodiments have been described above, the above embodiments can be grasped as follows.
In the first embodiment, the first axial fan 2 sends air with a swirl component reduced and an axial component increased compared to a single axial fan without a stationary blade. The second axial fan 3 and the third axial fan 4 have the swirl component reduced and the axial component increased to the first axial fan 2 as compared to a single axial fan having no stationary blade. It plays the role of sending in.
Also in the second embodiment, the first axial fan 2 sends air with a swirl component reduced and an axial component increased compared to a single axial fan that does not have a stationary blade. The second axial fan 3a plays a role of sending air having a reduced swirl component and an increased axial component to the first axial fan 2 as compared to a single fan having no stationary blade.

In the third embodiment, the first axial fan 2b and the second axial fan 3b have the swirl component reduced and the axial component increased as compared to a single axial fan having no stationary blade. Send it out. The third axial fan 4b plays a role of feeding air having a reduced swirl component and an increased axial component to the second axial fan 3b as compared to a single axial fan having no stationary blade.
In the fourth embodiment, the first axial fan 2b and the second axial fan 3b have the swirl component reduced and the axial component increased as compared to a single axial fan having no stationary blade. Send it out. The third axial flow fan 5 and the fourth axial flow fan 6 reduce the swirl component and increase the axial component to the second axial flow fan 3b as compared with a single axial flow fan having no stationary blade. It plays the role of sending in.

  That is, in the above embodiment, the swirl component is reduced and the axial component is increased on the exhaust side of a series axial fan connected with three or more axial fans, compared to a single axial fan without a stationary blade. At least one downstream axial fan for delivering the conditioned air is arranged. In addition, at least one upstream axial fan that feeds air having a reduced swirl component and an increased axial component to the downstream axial fan as compared to a single axial fan that does not have a stationary blade is downstream. It is connected to the intake side of the side axial fan.

  FIG. 8 is a view showing another example of the series axial fan 1 shown in FIG. In the serial axial fan 1 shown in FIG. 8, a rod-shaped first support rib 28 is provided instead of the stationary blade 25 of the first axial fan 2 of the serial axial fan 1 shown in FIG. At the same time, the stationary blade portion 7 is disposed at the end portion on the exhaust side of the first axial fan 2. The other structure is the same as that of the serial axial fan 1 shown in FIG.

  FIG. 9 is a bottom view of the stationary blade portion 7. The stationary blade portion 7 includes an annular portion 71 centering on the central axis J 1, four stationary blades 72 extending radially from the outer periphery of the annular portion 71, and a substantially rectangular frame 73 surrounding the annular portion 71 and the stationary blade 72. ing. The diameter of the outer periphery of the annular portion 71 is substantially the same as the diameter of the outer periphery of the base portion 24 of the first axial fan 2 shown in FIG. The frame 73 is attached to the end of the first housing 23 on the exhaust side. The inner surface of the frame 73 is smoothly connected to the inner surface of the first housing 23. As a result, a smooth air flow path is formed at the end of the in-line axial fan 1 on the exhaust side.

  In the serial axial fan 1, the stationary blade portion 7 is provided on the exhaust side of the first impeller 21, so that the axial component of the air sent from the first impeller 21 is increased as in the case of FIG. The For this reason, the static pressure of the air sent from the serial axial fan 1 is improved. In addition, in the serial axial fans 1a and 1b shown in FIGS. 5 and 6, instead of the stationary blades 25, 35a and 47, rod-shaped support ribs are provided, and the stationary blade portion 7 is provided on the exhaust side of the support ribs. May be attached.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible. For example, in the first embodiment, as shown in FIG. 10, the second axial fan 3 is turned upside down so that the second support rib 35 and the third support rib 45 sandwich the second impeller 31. They may be arranged apart from each other. Similarly, the serial axial fans 1b and 1c may have a structure in which the support ribs of the axial fans adjacent to each other are arranged apart from each other.

  In the fourth embodiment shown in FIG. 7, the first support rib 27 and the third support rib 54 may be disposed on the exhaust side of the first impeller 21 and the third impeller 51, respectively. Further, in addition to the structure, the second support rib 37 and the fourth support rib 64 may be disposed on the intake side of the second impeller 31 and the fourth impeller 61, respectively. In other words, the support rib of the odd-numbered axial fan from the exhaust side is disposed below the impeller of the axial fan, and the support rib of the even-numbered axial fan is the impeller of the axial fan. It may be arranged on the upper side. The vertical relationship between the support rib and the impeller may be further different.

  In FIG. 1, instead of the rod-like second support rib 35 of the second axial fan 3, a plate-like or blade-like shape having a larger width in the direction parallel to the central axis J <b> 1 than the second support rib 35. Support ribs may be provided. Similarly, the third axial fan 4 may be provided with plate-like or blade-shaped support ribs. Consider a case in which one or both of the support ribs of the second axial fan 3 and the support ribs of the third axial fan 4 have a plate shape or a blade shape. Even in this case, these support ribs are located between the first impeller 21 and the second impeller 31. At the same time, overlapping in the direction parallel to the central axis J1 prevents the air flow from being hindered. Also in the case shown in FIG. 10, one or both of the support ribs of the second axial fan 3 and the support ribs of the third axial fan 4 may have a plate shape or a blade shape. Also in other embodiments, the support ribs may be appropriately changed from a rod shape to a plate shape or a wing shape in order to increase the axial component of air by a desired degree.

  In the above embodiment, the series axial fan may be designed so that the number of impeller blades and support ribs adjacent to each other is different. Preferably, the number of impeller blades and support ribs adjacent to each other may be designed to be relatively prime. Thereby, the peak frequency of the noise generated in each of the blades and the support ribs is shifted, and the noise of the entire series axial fan is reduced.

  In the above embodiment, a cylindrical spacer having an inner surface that smoothly connects to the inner surface of each housing may be attached between the two axial fans. Further, one or two or more axial fans may be further connected in series to the intake side of the series axial fans 1, 1a to 1c, and the rotation directions of the impellers of two adjacent axial fans are the same. In some cases, a stationary blade is preferably provided between the two axial fans.

  The present invention can be used as a cooling fan for electronic devices or the like, and can also be used as a fan other than a cooling fan.

1, 1a to 1c In-line axial flow fan 11 Wind tunnel portion 21 First impeller 22 First motor portion 23 First housing 24 (first motor portion) base portion 25, 35a, 47 Stator blade 27, 28 First support rib 31 Second impeller 32 Second motor part 33 Second housing 34 (second motor part) Base part 35, 37 Second support rib 41, 51 Third impeller 42, 52 Third motor part 43, 53 Third housing 44 Base part (of the third motor part) 45, 54 Third support rib 61 Fourth impeller 62 Fourth motor part 63 Fourth housing 64 Fourth support rib 221 First rotor part 321 Second rotor part 421 Third rotor part J1 Central axis

Claims (10)

A series axial fan,
A first impeller located closest to the exhaust side;
A first motor unit that is attached to the rotor unit and rotates the first impeller about a central axis;
A second impeller located second from the exhaust side;
A second motor part that is attached to a rotor part and rotates the second impeller about the central axis;
A third impeller located third from the exhaust side;
A third motor part attached to the rotor part to rotate the third impeller around the central axis in a direction opposite to the second impeller;
A plurality of stationary blades positioned on the exhaust side of the first impeller and extending in a substantially radial direction around the central axis;
A cylindrical wind tunnel surrounding the outer periphery of the first impeller, the second impeller, and the third impeller;
A series axial fan characterized by comprising: The series axial fan according to claim 1,
The wind tunnel is
A first housing surrounding an outer periphery of the first impeller;
A second housing surrounding an outer periphery of the second impeller;
A third housing surrounding an outer periphery of the third impeller;
With
The series axial fan, wherein the plurality of stationary blades, the first housing, and the base portion of the first motor portion are formed as one member. The in-line axial fan according to claim 1 or 2,
A plurality of support ribs connecting the second motor part to the wind tunnel part;
A plurality of other support ribs connecting the third motor part to the wind tunnel part;
Further comprising
The series axial fan, wherein the plurality of support ribs and the other plurality of support ribs are located between the second impeller and the third impeller and overlap in a direction parallel to the central axis. . A series axial fan,
A first impeller located closest to the exhaust side;
A first motor unit that is attached to the rotor unit and rotates the first impeller about a central axis;
A second impeller located second from the exhaust side;
A second motor unit that is attached to the rotor unit and rotates the second impeller about the central axis in a direction opposite to the first impeller;
A third impeller located third from the exhaust side;
A third motor unit that is attached to a rotor unit and rotates the third impeller about the central axis;
A plurality of stationary blades positioned between the second impeller and the third impeller and extending in a substantially radial direction around the central axis;
A cylindrical wind tunnel surrounding the outer periphery of the first impeller, the second impeller, and the third impeller;
A series axial fan characterized by comprising: The in-line axial fan according to claim 4,
The wind tunnel is
A first housing surrounding an outer periphery of the first impeller;
A second housing surrounding an outer periphery of the second impeller;
A third housing surrounding an outer periphery of the third impeller;
With
The series axial fan, wherein the plurality of stationary blades, the third housing, and the base portion of the third motor portion are formed as one member. The in-line axial fan according to claim 4 or 5,
A plurality of support ribs connecting the first motor part to the wind tunnel part;
A plurality of other support ribs connecting the second motor part to the wind tunnel part;
Further comprising
The series axial fan, wherein the plurality of support ribs and the other plurality of support ribs are located between the first impeller and the second impeller and overlap in a direction parallel to the central axis. . A series axial fan,
A first impeller located closest to the exhaust side;
A first motor unit that is attached to the rotor unit and rotates the first impeller about a central axis;
A second impeller located second from the exhaust side;
A second motor part that is attached to a rotor part and rotates the second impeller about the central axis;
A third impeller located third from the exhaust side;
A third motor unit that is attached to a rotor unit and rotates the third impeller about the central axis;
A plurality of stationary blades positioned on the exhaust side of the first impeller and extending in a substantially radial direction around the central axis;
A plurality of other stationary blades positioned between the first impeller and the second impeller and extending substantially in the radial direction;
A cylindrical wind tunnel surrounding the outer periphery of the first impeller, the second impeller, and the third impeller;
A series axial fan characterized by comprising: The series axial fan according to claim 7,
The wind tunnel is
A first housing surrounding an outer periphery of the first impeller;
A second housing surrounding an outer periphery of the second impeller;
A third housing surrounding an outer periphery of the third impeller;
With
The base portions of the plurality of stationary blades, the first housing, and the first motor portion are formed as one member, and the base portions of the other plurality of stationary blades, the second housing, and the second motor portion are formed. A series axial fan characterized by being formed as one member. A series axial fan,
A first impeller located closest to the exhaust side;
A first motor unit that is attached to the rotor unit and rotates the first impeller about a central axis;
A second impeller located second from the exhaust side;
A second motor unit that is attached to the rotor unit and rotates the second impeller about the central axis in a direction opposite to the first impeller;
A third impeller located third from the exhaust side;
A third motor unit that is attached to a rotor unit and rotates the third impeller about the central axis;
A fourth impeller located fourth from the exhaust side;
A fourth motor unit that is attached to the rotor unit and rotates the fourth impeller about the central axis in a direction opposite to the third impeller;
A cylindrical wind tunnel surrounding the outer periphery of the first impeller, the second impeller, the third impeller, and the fourth impeller;
A series axial fan characterized by comprising: The in-line axial fan according to claim 9,
A plurality of first support ribs connecting the first motor part to the wind tunnel part;
A plurality of second support ribs connecting the second motor part to the wind tunnel part;
A plurality of third support ribs connecting the third motor part to the wind tunnel part;
A plurality of fourth support ribs connecting the fourth motor part to the wind tunnel part;
Further comprising
The plurality of first support ribs and the plurality of second support ribs are located between the first impeller and the second impeller and overlap in a direction parallel to the central axis, and the plurality of third support ribs And the plurality of fourth support ribs are located between the third impeller and the fourth impeller and overlap in a direction parallel to the central axis.

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