Axial flow fan

Abstract

To provide an axial flow fan having PQ characteristics improved, compared to the case of covering a lead with a rib.SOLUTION: The axial flow fan includes an air inlet side fan and an air outlet side fan arranged in series, the air inlet side fan including a center shaft, a first impeller rotatable around the center shaft, a first motor supporting the first impeller on the radial inside, a first motor housing supporting the first motor, a first housing arranged on the radial outside of the first impeller, and a third rib connecting the first motor housing and the first housing, the air outlet fan including a second impeller rotatable around the center shaft, a second motor supporting the second impeller, a second motor housing supporting the second motor, a second housing arranged on the radial outside of the second impeller, and a fourth rib connecting the second motor housing and the second housing. At least parts of the third rib and the fourth rib overlap with each other in the peripheral direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] A known type of axial fan is a double axial fan that consists of an intake fan and an exhaust fan arranged in series. Axial fans are required to have improved PQ characteristics (air volume-static pressure characteristics). The motor that drives the impeller of the axial fan is placed in the center of the axial fan's wind tunnel, and power is supplied from outside the axial fan via lead wires (hereinafter simply referred to as "leads"). Since the leads cross the axial fan's wind tunnel, they vibrate due to the air flow inside the wind tunnel, which causes a decrease in the PQ characteristics.

[0003] The motor that drives the impeller is accommodated in a motor housing, and this motor housing is supported by ribs that extend from the motor housing toward the housing that forms the air tunnel of the axial fan. A structure that reduces vibration of the reeds by covering the reeds with ribs is conventionally known (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4033891 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the reeds are covered with ribs as in the past, there was a problem that the ribs become thicker, the wind tunnel area decreases, and the effect on the air flow becomes larger, degrading the PQ characteristics. For this reason, there was previously room for improvement in the PQ characteristics.

[0006] An object of the present invention is to provide an axial flow fan having improved PQ characteristics compared to a fan in which the reeds are covered with ribs. [Means for solving the problem]

[0007] A first exemplary invention of the present application is an axial flow fan in which an intake side fan and an exhaust side fan are arranged in series, the intake side fan includes a central axis, a first impeller rotatable around the central axis, a first motor supporting the first impeller on the radially inner side, a first motor housing supporting the first motor, a first housing arranged radially outward of the first impeller, a first rib connecting the first motor housing and the first housing, and a first lead extending radially outward from the first motor housing, and the exhaust side fan includes a second impeller rotatable around the central axis, a second motor supporting the second impeller on the radially inner side, a second motor housing supporting the second motor, and a first lead extending radially outward from the first motor housing. The motor housing includes a second housing arranged on the outside, a second rib connecting the second motor housing and the second housing, and a second lead extending radially outward from the second motor housing, wherein at least a portion of the first rib and the second rib overlap when viewed in the axial direction, and at least a portion of the first lead and the second lead overlap when viewed in the axial direction, and the first lead and the second lead are on one circumferential side of the first rib and the second rib on the radially inner side of the first housing and on the other circumferential side of the first rib and the second rib on the radially outer side of the first housing, and the first lead and the second lead are on the exhaust side of the intake side fan than the first rib and on the intake side of the exhaust side fan than the second rib.

[0008] A second exemplary invention of the present application is an axial flow fan having an intake side fan and an exhaust side fan arranged in series, the intake side fan includes a central axis, a first impeller rotatable around the central axis, a first motor supporting the first impeller on the radially inner side, a first motor housing supporting the first motor, a first housing arranged radially outward of the first impeller, and a third rib connecting the first motor housing and the first housing; the exhaust side fan includes a second impeller rotatable around the central axis, a second motor supporting the second impeller, a second motor housing supporting the second motor, a second housing arranged radially outward of the second impeller, and a fourth rib connecting the second motor housing and the second housing, at least a portion of the third rib and the fourth rib overlap in the circumferential direction, The rotor includes a first rib that radially connects the first motor housing and the first housing, and a second rib that radially connects the second motor housing and the second housing, and either the first rib or the second rib has an axial protruding portion that protrudes to one axial side, and the axial protruding portion has an other-side recess that is recessed to the other axial side. Effect of the Invention

[0009] According to the first exemplary aspect of the present application, it is possible to provide an axial flow fan with improved PQ characteristics compared to a case in which the leads are covered with ribs.

[0010] According to the second exemplary aspect of the present invention, it is possible to provide an axial flow fan with improved PQ characteristics. [Brief description of the drawings]

[0011] [Figure 1] 1 is a perspective view showing a fan according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of the fan 10, with the exhaust fan 200 oriented in front of the intake fan 100. [Diagram 3] 1 is a side view of the intake fan 100 as viewed from the other axial side. [Figure 4] FIG. 2 is a side view of the exhaust fan 200 as viewed from one axial side. [Diagram 5] 2 is a cross-sectional view of the fan 10 taken perpendicular to the X-axis. [Figure 6]FIG. 11 is a side view of an intake side fan 100A according to a second embodiment of the present invention, as viewed from the axial exhaust port side. [Figure 7] FIG. 11 is a side view of an exhaust fan 200A according to a second embodiment of the present invention, as viewed from the axial intake port side. [Figure 8] 10 is a cross-sectional view perpendicular to the X-axis of a fan according to a second embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a fan according to an embodiment of the present invention will be described with reference to the drawings. Note that in the drawings, the scale and number of components may differ from the actual structure in order to make each component easier to understand.

[0013] In addition, in the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional Cartesian coordinate system. In the XYZ coordinate system, the Y axis direction is a direction parallel to the axis of the central axis J shown in Fig. 1. The Z axis direction is a radial direction relative to the central axis J, which is the up-down direction in Fig. 1. The X axis direction is a direction perpendicular to both the Z axis direction and the Y axis direction. In each of the X axis direction, the Y axis direction, and the Z axis direction, the side indicated by the arrow in the drawing is the + side, and the opposite side is the - side.

[0014] In the following description, the positive side (+Y side) in the Y-axis direction is called the "front side" or "one side", and the negative side (-Y side) in the Y-axis direction is called the "rear side" or "other side". The rear side (other side) and the front side (one side) are names used simply for the purpose of description and do not limit the actual positional relationship and direction. Unless otherwise specified, the direction parallel to the central axis J (Y-axis direction) is simply called the "axial direction", the radial direction centered on the central axis J is simply called the "radial direction", and the circumferential direction centered on the central axis J, i.e., around the axis of the central axis J (θ direction), is simply called the "circumferential direction". The side approaching the central axis J in the radial direction is called the "radial inner side", and the side moving away from the central axis J is called the "radial outer side". In the circumferential direction, the side indicated by the arrow in the figure is the + side, and the opposite side is the - side. The positive circumferential side (+θ side) is referred to as "one side," and the negative circumferential side (-θ side) is referred to as "the other side."

[0015] In this specification, "extending in the axial direction" includes not only extending strictly in the axial direction (Z-axis direction) but also extending in a direction tilted at an angle of less than 45° to the axial direction. In addition, in this specification, "extending in the radial direction" includes not only extending strictly in the radial direction, i.e., in a direction perpendicular to the axial direction (Z-axis direction), but also extending in a direction tilted at an angle of less than 45° to the radial direction. Furthermore, "parallel" includes not only being strictly parallel but also being tilted at an angle of less than 45° to each other.

[0016] [First embodiment] <Overall composition> FIG 1 is a perspective view showing a fan according to a first embodiment of the present invention. Fan 10 is an axial fan. Fan 10 has an intake side fan 100 and an exhaust side fan 200. Fan 10 is configured by arranging intake side fan 100 and exhaust side fan 200 in series. Intake side fan 100 and exhaust side fan 200 are aligned in the axial direction. FIG. 1 is a perspective view showing the fan 10 with the intake fan 100 oriented in front of the exhaust fan 200. FIG. FIG. 2 is a perspective view showing the fan 10 with the exhaust fan 200 oriented in front of the intake fan 100. As shown in FIG.

[0017] As shown in Fig. 1, the intake side fan 100 includes an impeller 120 that is rotatable about a central axis J, and a housing 101 that is arranged radially outside the impeller 120. The impeller 120 rotates in the direction indicated by arrow A in Fig. 1. The impeller 120 rotates on the other circumferential side. The one circumferential side is the front side of the impeller 120 in the rotation direction, and the other circumferential side is the rear side of the impeller 120 in the rotation direction.

[0018] The housing 101 includes a cylindrical portion 103 having a cylindrical shape with an axis along the central axis J, a flange portion 102 arranged on the other axial side of the cylindrical portion 103, and a flange portion 104 arranged on one axial side of the cylindrical portion 103. The surface on the other axial side of the cylindrical portion 103 is flush with the surface on the other axial side of the flange portion 102. The surface on one axial side of the cylindrical portion 103 is flush with the surface on one axial side of the flange portion 104.

[0019] As shown in Fig. 2, the exhaust side fan 200 includes an impeller 220 that is rotatable around a central axis J, and a housing 201 arranged radially outside the impeller 220. The impeller 220 rotates in the direction indicated by the arrow B in Fig. 2. The impeller 220 rotates to one side in the circumferential direction. The rotation direction of the intake side fan 100 is opposite to that of the exhaust side fan 200. The fan 10 is a counter-rotating fan.

[0020] The housing 201 includes a cylindrical portion 203 having a cylindrical shape with an axis along the central axis J, a flange portion 202 arranged on one axial side of the cylindrical portion 203, and a flange portion 204 arranged on the other axial side of the cylindrical portion 203. The surface on one axial side of the cylindrical portion 203 is flush with the surface on one axial side of the flange portion 202. The surface on the other axial side of the cylindrical portion 203 is flush with the surface on the other axial side of the flange portion 204.

[0021] Fan 10 is formed by butting the other axial surface of flange portion 102 against one axial surface of flange portion 202, and fixing intake side fan 100 and exhaust side fan 200 with, for example, bolts. The one axial surface of flange portion 202 faces the other axial surface of flange portion 102 in the axial direction.

[0022] FIG. 3 is a side view of the intake fan 100 as viewed from the other axial side. Intake side fan 100 includes an impeller 120 and a motor 160 (described below) that supports impeller 120. Intake side fan 100 includes a motor housing 130 that supports motor 160, and ribs 140, 145, 146, 147, 148, and 149 that extend radially from motor housing 130 toward housing 101 on the exhaust side of intake side fan 100 and support motor housing 130. Motor housing 130, ribs 140, 145, 146, 147, 148, and 149, and housing 101 are all the same member formed, for example, by die casting.

[0023] The ribs 140 , 145 , 146 , 147 , 148 , and 149 extend straight from the motor housing 130 toward the housing 101 , inclining radially and circumferentially to one side, that is, toward the front side in the rotation direction of the intake fan 100 .

[0024] Intake side fan 100 includes a substrate 131 on which a drive circuit for driving motor 160 is mounted. Intake side fan 100 includes leads 150 extending radially outward from motor housing 130. Motor 160 receives power from the outside via leads 150 that are connected by soldering to terminals 132 of substrate 131. Leads 150 are housed in, for example, a tube, and the cross section of the tube is approximately circular.

[0025] The surfaces of the ribs 140, 145, 146, 147, 148, and 149 on the other axial side may be flush with the surface of the flange portion 102 on the other axial side. The rib 140 has a recess 141 recessed in one axial direction on the surface on the other axial side. The connection point between the terminal 132 and the lead 150, i.e., the radially inner end of the lead 150, is located on one circumferential side of the connection point between the rib 140 and the motor housing 130. The lead 150 fits into the recess 141. The cylindrical portion 103 has a recess 135 recessed in one axial direction on the surface on the other axial side. The recess 135 is located on the other circumferential side of the connection point between the rib 140 and the housing 101. The flange portion 102 has a recess 136 recessed in one axial direction on the surface on the other axial side. The lead 150 fits into the recess 135 and the recess 136.

[0026] FIG. 4 is a side view of the exhaust fan 200 as viewed from one axial side. The exhaust side fan 200 includes an impeller 220 and a motor 260 (described below) that supports the impeller 220. The exhaust side fan 200 includes a motor housing 230 that supports the motor 260, and ribs 240, 245, 246, 247, 248, and 249 that extend radially from the motor housing 230 toward the housing 201 on the intake side of the exhaust side fan 200 and support the motor housing 230. The motor housing 230, the ribs 240, 245, 246, 247, 248, and 249, and the housing 201 are all the same member formed, for example, by die casting.

[0027] The ribs 240 , 245 , 246 , 247 , 248 and 249 extend straight from the motor housing 230 towards the housing 201 , inclining radially and circumferentially to one side, that is, towards the rear side in the rotation direction of the exhaust fan 200 .

[0028] A surface on one axial side of the motor housing 230 faces a surface on the other axial side of the motor housing 130 in the axial direction. A surface on one axial side of the rib 240 faces a surface on the other axial side of the rib 140 in the axial direction. At least a part of the rib 140 and the rib 240 overlap when viewed from the axial direction. A surface on one axial side of the rib 245 faces a surface on the other axial side of the rib 145 in the axial direction. A surface on one axial side of the rib 246 faces a surface on the other axial side of the rib 146 in the axial direction. A surface on one axial side of the rib 247 faces a surface on the other axial side of the rib 147 in the axial direction. A surface on one axial side of the rib 248 faces a surface on the other axial side of the rib 148 in the axial direction. A surface on one axial side of the rib 249 faces a surface on the other axial side of the rib 149 in the axial direction.

[0029] The exhaust side fan 200 includes a board 231 on which a drive circuit for driving a motor 260 is mounted. The exhaust side fan 200 includes leads 250 extending radially outward from a motor housing 230. The motor 260 receives power from the outside via the leads 250 which are connected by soldering to terminals 232 of the board 231. The leads 250 are housed in, for example, a tube, and the cross section of the tube is approximately circular.

[0030] The surfaces of the ribs 240, 245, 246, 247, 248, and 249 on one axial side may be flush with the surface of the flange portion 202 on one axial side. The rib 240 has a recess 241 recessed in the other axial side on the surface on one axial side. The connection point between the terminal 232 and the lead 250, i.e., the radially inner end of the lead 250, is located on one circumferential side of the connection point between the rib 240 and the motor housing 230. The lead 250 fits into the recess 241. The cylindrical portion 203 has a recess 235 recessed in the other axial side on the surface on one axial side. The recess 235 is located on the other circumferential side of the connection point between the rib 240 and the housing 201. The flange portion 202 has a recess 236 recessed in the other axial side on the surface on one axial side. The lead 250 fits into the recess 235 and the recess 236.

[0031] At least a portion of the reeds 150 and 250 overlap when viewed in the axial direction. The reeds 150 and 250 are on one circumferential side of the ribs 140 and 240 on the radially inner side of the housing 101. The reeds 150 and 250 are on the other circumferential side of the ribs 140 and 240 on the radially outer side of the housing 101. The reeds 150 and 250 are on the exhaust side of the intake side fan 100 compared to the ribs 140, and on the intake side of the exhaust side fan 200 compared to the ribs 240.

[0032] The recess 241 faces the recess 141 in the axial direction. The recess 235 faces the recess 135 in the axial direction. The recess 236 faces the recess 136 in the axial direction.

[0033] 5 is a side cross-sectional view of fan 10 taken along a plane perpendicular to the X-axis and passing through central axis J. In Fig. 5, leads 150 and 250 are omitted so that the shape of through hole 300 can be easily seen. The intake side fan 100 includes a motor 160. The impeller 120 is rotated by the motor 160. The motor housing 130 accommodates the motor 160. The exhaust side fan 200 includes a motor 260. The impeller 220 is rotated by the motor 260. The motor housing 230 accommodates the motor 260.

[0034] The motor 160 includes a stator 161, a rotor 162, a shaft 163, bearings 164 and 165, and a substrate 131. The substrate 131 and the stator 161 are fixed to the motor housing 130. The rotor 162 is disposed radially outside the stator 161 via a gap. The rotor 162 has a bottomed cylindrical shape that covers the stator 161 from one axial side. The shaft 163 is disposed along the central axis J and fixed to the center of rotation of the rotor 162. The shaft 163 is rotatably supported by bearings 164 and 165 fixed to the motor housing 130. The impeller 120 is fixed to the rotor 162 and rotates about the central axis J as the rotor 162 rotates.

[0035] The motor 260 includes a stator 261, a rotor 262, a shaft 263, a bearing 264, a bearing 265, and a substrate 231. The substrate 231 and the stator 261 are fixed to the motor housing 230. The rotor 262 is disposed radially outside the stator 261 via a gap. The rotor 262 has a bottomed cylindrical shape that covers the stator 261 from one axial side. The shaft 263 is disposed along the central axis J and fixed to the rotation center of the rotor 262. The shaft 263 is rotatably supported by bearings 264 and 265 fixed to the motor housing 230. The impeller 220 is fixed to the rotor 262 and rotates about the central axis J as the rotor 262 rotates.

[0036] The leads 150 and 250 pass through a through hole 300 formed by the recesses 141 and 241. The through hole 300 is elliptical or oblong when viewed from the radial direction. Furthermore, the surfaces of the ribs 140 and 240 that come into contact with the leads 150 and 250 are curved. The leads 150 and 250 are sandwiched and fixed by the ribs 140 and 240. This reduces vibrations caused by air flow and suppresses deterioration of the PQ characteristics.

[0037] In this embodiment, the leads 150 and 250, which are separate wires, are arranged to pass through the through hole 300. However, the leads 150 and 250 may be housed together in a single tube to form a single wire, and the tube may be arranged to pass through the through hole 300.

[0038] <Fun 10 Actions and Effects> Next, the action and effect of the fan 10 will be described.

[0039] In the invention according to the above-mentioned embodiment, there is provided an axial flow fan in which an intake side fan and an exhaust side fan are arranged in series, the intake side fan includes a central axis, a first impeller rotatable around the central axis, a first motor supporting the first impeller on the radially inner side, a first motor housing supporting the first motor, a first housing arranged on the radially outer side of the first impeller, a first rib connecting the first motor housing and the first housing, and a first lead extending radially outward from the first motor housing, and the exhaust side fan includes a second impeller rotatable around the central axis, a second motor supporting the second impeller on the radially inner side, a second motor housing supporting the second motor, and a first lead extending radially outward from the second impeller. the first motor housing includes a second housing arranged radially outward, a second rib connecting the second motor housing and the second housing, and a second lead extending radially outward from the second motor housing, wherein at least a portion of the first rib and the second rib overlap when viewed in the axial direction, and at least a portion of the first lead and the second lead overlap when viewed in the axial direction, the first lead and the second lead are on one circumferential side of the first rib and the second rib on the radially inner side of the first housing and on the other circumferential side of the first rib and the second rib on the radially outer side of the first housing, and the first lead and the second lead are on the exhaust side of the intake side fan than the first rib and on the intake side of the exhaust side fan than the second rib. Since the first lead and the second lead can be fixed by the first rib and the second rib, deterioration of the PQ characteristics can be suppressed compared to a case where the leads are not fixed.

[0040] Moreover, the one circumferential side is a front side in a rotation direction of the first impeller, and the other circumferential side is a rear side in a rotation direction of the first impeller. Since the first and second reeds are located radially outward on the negative pressure side of the first and second ribs, turbulence in the air flow can be suppressed, and high air volume characteristics can be obtained.

[0041] The first rib extends straight from the first motor housing toward the first housing, inclining radially and forward in the rotation direction of the intake fan. As the impeller of the intake fan rotates, it intersects with the first rib sequentially from the outside in the radial direction, thereby reducing air turbulence and suppressing noise.

[0042] In addition, the first rib has a first recess that is recessed toward one axial direction on the other axial side, and the second rib has a second recess that is recessed toward the other axial direction on one axial side at a position axially opposite to the first recess, and the first lead and the second lead pass through a through hole formed by the first recess and the second recess. Since the first lead and the second lead pass through the through hole, the first lead and the second lead are less likely to be damaged.

[0043] Moreover, the through hole may be elliptical or oblong when viewed in a radial direction. The first and second leads enter the tubes extending in the radial direction and are approximately circular when viewed from the radial direction. By making the through holes approximately elliptical or oval when viewed from the radial direction, the leads extend straight in the radial direction and the area blocking the air tunnel can be reduced, so that air turbulence can be reduced and high air volume characteristics can be obtained. The shape of the through holes may be any shape that does not excessively compress the leads passing through them and does not cause large deformation of the leads.

[0044] Moreover, the first rib and the second rib have curved surfaces which come into contact with the first lead and the second lead. The first rib and the second rib come into contact with the first lead and the second lead at their curved surfaces, so that the first lead and the second lead are less likely to be damaged.

[0045] At least a portion of the first rib fits into a recess in the second rib (see FIG. 5). The through holes can be formed by combining recess shapes that are easy to mold with a mold. Also, by making the shape of the through holes such that the leads can easily fit into them, air turbulence is less likely to occur.

[0046] In addition, the intake side fan has a plurality of third ribs extending radially from the first motor housing toward the first housing and supporting the first motor housing on the exhaust side of the intake side fan, and the exhaust side fan has a plurality of fourth ribs extending radially from the second motor housing toward the second housing and supporting the second motor housing on the intake side of the exhaust side fan. The first motor housing and the second motor housing can be stably supported.

[0047] Furthermore, the rotation direction of the intake fan is opposite to that of the exhaust fan. By using counter-rotating fans, in which the rotation direction of the intake fan and the exhaust fan are opposite, it is possible to obtain high static pressure characteristics.

[0048] Furthermore, a counter-rotating fan having a plurality of ribs spaced at different circumferential intervals has the following features and advantages.

[0049] The first rib, the second rib, the plurality of third ribs, and the plurality of fourth ribs are spaced apart from one another in the circumferential direction. By varying the circumferential intervals of the multiple ribs, the timing at which they overlap in the axial direction with the blades of the impeller rotating in the circumferential direction varies, thereby suppressing noise. Here, the first rib and the second rib are shaped so that at least a portion of them overlap in the axial direction and are integrated.

[0050] In addition, the circumferential spacing of the first rib, the multiple third ribs, and the multiple fourth ribs differs in the timing at which they simultaneously overlap in the axial direction with the multiple blades provided on the first impeller rotating in the circumferential direction. Noise can be suppressed by having the multiple ribs and multiple blades overlap at different times in the axial direction.

[0051] In addition, the circumferential spacing of the first rib, the multiple third ribs, and the multiple fourth ribs differs in the timing at which they simultaneously overlap in the axial direction with the multiple blades provided on the second impeller rotating in the circumferential direction. Noise can be suppressed by having the multiple ribs and multiple blades overlap at different times in the axial direction.

[0052] [Second embodiment] A second embodiment of the present invention will now be described. The motor that drives the impeller of the axial fan is placed in the center of the axial fan's wind tunnel, and a rib is provided to support the motor. The ribs of the intake fan and the exhaust fan overlap in the axial direction and are integrated. However, the connection disturbs the air flow, which is a factor in reducing the PQ characteristics. According to this embodiment, it is possible to provide an axial fan with improved PQ characteristics.

[0053] 6 is a side view of an intake side fan 100A according to a second embodiment of the present invention, as viewed from the other axial side. In Fig. 6, the same components as those in the first embodiment are denoted by the same reference numerals. The intake side fan 100A includes a motor housing 130A that supports a motor 160, and ribs 140A, 146A, and 148A that extend radially from the motor housing 130A toward the housing 101A on the exhaust side of the intake side fan 100A and support the motor housing 130A. The motor housing 130A, the ribs 140A, 146A, and 148A, and the housing 101A are all a same member formed, for example, by die casting.

[0054] The ribs 140A, 146A, and 148A extend from the motor housing 130A toward the housing 101A, and also extend to the other axial side and circumferentially overlap at least a portion of the ribs 245A, 247A, and 249A, which will be described later.

[0055] Rib 140A and rib 240A may have a recess 141 recessed toward one axial direction on the surface on the other axial direction side, but it is desirable that the recess's closest axial side is on the other axial side of the surface on the other axial direction of flange portion 102A or 202A.

[0056] 7 is a side view of an exhaust fan 200A according to a second embodiment of the present invention, seen from the air inlet side. In Fig. 7, the same components as those in the first embodiment are denoted by the same reference numerals. The exhaust-side fan 200A includes a motor housing 230A that supports a motor 260, and ribs 240A, 245A, 247A, and 249A that extend radially from the motor housing 230A toward the housing 201A on the intake side of the exhaust-side fan 200A and support the motor housing 230. The motor housing 230A, the ribs 240A, 245A, 247A, and 249A, and the housing 201A are all the same member formed, for example, by die casting.

[0057] Rib 240A extends from motor housing 230A toward housing 201A. The ribs 245A, 247A, and 249A extend from the motor housing 230A toward the housing 201A, and extend to one axial side to overlap at least a portion of the ribs 140A, 146A, and 148A in the circumferential direction.

[0058] A surface on one axial side of the motor housing 230A faces in the axial direction to a surface on the other axial side of the motor housing 130A. A surface on one axial side of the rib 240A faces in the axial direction to a surface on the other axial side of the rib 140A. At least a portion of the rib 140A and the rib 240A overlap when viewed in the axial direction.

[0059] 8 is a cross-sectional view of a fan according to a second embodiment of the present invention taken along a line perpendicular to the X-axis, in which the same components as those in the first embodiment are denoted by the same reference numerals.

[0060] <Actions and Effects of the Second Embodiment> Next, the operation and effect of the second embodiment will be described.

[0061] In the above-described embodiment of the invention, An axial flow fan having an intake fan and an exhaust fan arranged in series, The intake side fan is A central axis, A first impeller rotatable around the central axis; A first motor that supports the first impeller on the radially inner side; a first motor housing supporting the first motor; A first housing disposed radially outward of the first impeller; a third rib connecting the first motor housing and the first housing; Equipped with The exhaust side fan is A second impeller rotatable around the central axis; A second motor supporting the second impeller; a second motor housing supporting the second motor; A second housing disposed radially outside the second impeller; a fourth rib connecting the second motor housing and the second housing; Equipped with The third rib and the fourth rib at least partially overlap in the circumferential direction. Since the third rib and the fourth rib overlap in the circumferential direction, the rib can be made seamless in the axial direction. This eliminates air turbulence caused by seams and suppresses deterioration of the PQ characteristics. Furthermore, since the third rib and the fourth rib are made thicker in the axial direction, the strength of the ribs can be increased, thereby suppressing vibration, improving the PQ characteristics, and reducing noise.

[0062] The third rib includes a third protruding portion that protrudes to an exhaust side end surface portion of the fourth rib. By making the exhaust side end surface portions of the third rib and the fourth rib the same, it is possible to make the effects of the third rib and the fourth rib on the PQ characteristics equal.

[0063] The fourth rib includes a fourth protruding portion that protrudes to an intake side end surface portion of the third rib. By making the intake side end surface portions of the fourth rib and the third rib the same, the effects of the fourth rib and the third rib on the PQ characteristics can be made equivalent.

[0064] a first rib that radially connects the first motor housing and the first housing; a second rib that radially connects the second motor housing and the second housing; Equipped with Either the first rib or the second rib further includes an axial protruding portion protruding to one side in the axial direction, The axial protruding portion has an other-side recess that is recessed to the other axial side. By providing the other-side recess in the axial protruding portion, the recess can be provided without impairing the strength of the first rib or the second rib.

[0065] the intake side motor includes a first lead extending radially outward from the first motor housing, the exhaust side motor includes a second lead extending radially outward from the second motor housing, At least a portion of the first lead and the second lead fits into the other-side recess.

[0066] The first rib and the second rib at least partially overlap when viewed in the axial direction. The first rib and the second rib overlap when viewed from the axial direction, thereby forming the other-side recess and a hole. By passing a lead or the like through the hole, vibration of the lead or the like can be suppressed.

[0067] The applications of the motors of the above-described embodiments are not particularly limited. Furthermore, the above-described configurations can be appropriately combined within a range not mutually contradictory.

[0068] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. These embodiments and modifications are included in the scope and gist of the present invention, and are also included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0069] 10 Fan 100 Intake fan 200 Exhaust fan

Claims

1. An axial flow fan having an intake fan and an exhaust fan arranged in series, The intake side fan is A central axis, A first impeller rotatable about the central axis; A first motor that supports the first impeller on a radially inner side; a first motor housing supporting the first motor; A first housing disposed radially outward of the first impeller; a third rib connecting the first motor housing and the first housing; Equipped with The exhaust side fan is A second impeller rotatable around the central axis; A second motor supporting the second impeller; a second motor housing supporting the second motor; A second housing disposed radially outward of the second impeller; a fourth rib connecting the second motor housing and the second housing; Equipped with At least a portion of the third rib and the fourth rib overlap in a circumferential direction, a first rib that radially connects the first motor housing and the first housing; a second rib that radially connects the second motor housing and the second housing; Equipped with Either the first rib or the second rib has an axial protruding portion protruding to one side in the axial direction, The axial protruding portion has an other-side recess recessed to the other axial side. Axial fan.

2. The third rib includes a third protruding portion protruding to an exhaust side end surface portion of the fourth rib. The axial fan according to claim 1 .

3. The fourth rib includes a fourth protruding portion protruding to an intake side end surface portion of the third rib.

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

4. the first motor includes a first lead extending radially outward from the first motor housing; the second motor includes a second lead extending radially outward from the second motor housing; At least a portion of the first lead and the second lead fits into the other-side recess. The axial fan according to claim 1 .

5. At least a portion of the first rib and the second rib overlap when viewed in the axial direction.

5. An axial fan according to claim 1 or 4.

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