JP2019090343A - Blower device - Google Patents

Abstract

To provide a blower device capable of blowing air while securing air volume characteristics even when there is no sufficient space near an intake port arranged in the lateral face of the device.SOLUTION: A blower device 100 includes an impeller as part of a centrifugal fan, and a duct housing 300 including a space via which fluid is guided to the impeller, the duct housing 300 having an intake port 304 and an exhaust port 305 opening in a direction perpendicular to the rotation axis of the impeller, the impeller being located between the intake port 304 and the exhaust port 305, the duct housing 301 having a first curved surface and a second curved surface 301d provided inside, the second curved surface 301d being provided with a plurality of protruded parts 307.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a blower apparatus.

  Blower devices using centrifugal fans are widely used for cooling of home appliances, office automation equipment, industrial equipment, ventilation, air conditioning, cooling of equipment for vehicles, and the like. For example, a blower apparatus using a centrifugal fan for cooling a battery pack mounted on a hybrid vehicle or an electric vehicle is known (see, for example, Patent Document 1).

  The cooling blower 10 described in Patent Document 1 is disposed adjacent to the side surface of the battery pack 100. By driving the blower motor of the motor unit 14 and rotating the blower fan 12 having a plurality of blades, air is sucked into the blower fan 12 from the air inlet 18 and is fed as the blower fan 12 rotates. The pumped air is guided along the inner peripheral wall of the case 16 to the spout of the case 16. Then, the battery pack 100 is supplied to the battery pack 100 via a duct connected to the spout, and the battery cells disposed in the battery pack 100 are cooled.

  However, in Patent Document 1, the cooling blower 10 disposed adjacent to the side surface of the battery pack 100 has the intake port 18 located on the side surface of the cooling blower 10. In other words, the intake port 18 is located in the direction orthogonal to the direction of supply to the battery pack 100. Depending on the environment of the space in which the cooling blower 10 is disposed, another device or apparatus may be disposed in proximity to the space in the vicinity of the intake port 18. In such an environment, the air can not be sufficiently sucked into the blower fan 12 from the intake port 18, and a required air flow characteristic can not be obtained. As a result, the ability to cool the battery cells of the battery pack 100 is reduced.

  As in the case of the cooling blower of Patent Document 1, when it is difficult to suck in air directly from the air intake, a blower provided with a suction flow path for guiding the air from the one direction to the air intake along the side of the air intake is used. (See, for example, Patent Document 2). The blower shown in Patent Document 2 includes a centrifugal impeller 1 and a scroll 2 having a suction port 3 (corresponding to the suction port of Patent Document 1) facing the centrifugal impeller 1. The suction port of the scroll 2 In a blower comprising a suction passage 9 for guiding the suction port 3 from one direction along a side surface 2a on the three side, an air inflow direction and the centrifugal impeller are at the inlet side of the suction passage 9 A tongue guide 10 whose axial width G 'is set to be smaller than the axial width B of the suction passage 9 is provided on the side opposite to the rotational direction 1 of the suction passage 9, and the suction air flow It flows in through the clearance S2 formed between the suction flow passage 9 and the suction passage 9. Further, a swirl flow suppressing means 11 for suppressing a swirl flow of the suction air flow is provided at a flow passage width intermediate portion on the inlet side of the suction flow passage 9. With this structure, performance stability in a large air volume range, improvement of air volume-static pressure characteristics, and reduction of operation noise are achieved.

JP, 2016-107703, A JP, 2006-299953, A

  However, in the case of the air blower described in Patent Document 2, since the inlet of the suction flow passage 9 is formed to be large, the middle of the flow passage width on the inlet side of the tongue guide 10 and the suction flow passage 9 is Although it is possible to provide the swirl flow suppressing means 11 for suppressing the swirl flow of the suction air flow, if the inlet of the suction flow passage 9 can not be formed large due to the restriction of the space where the blower is installed, the suction flow passage 9 Will reduce the number of entrances. As a result, there is a possibility that the air volume characteristic of the blower may be lowered.

  An object of the present invention is to provide a blower apparatus having a good air volume characteristic even when a sufficient space can not be secured in the vicinity of the side surface.

  The present invention comprises an impeller constituting a centrifugal fan, and a duct housing provided with a space for introducing a fluid to the impeller, wherein the duct housing includes an air inlet and an exhaust opening in a direction orthogonal to the rotation axis of the impeller. A port is provided, the impeller is positioned between the air inlet and the air outlet, and a first curved surface and a second curved surface are provided inside the duct housing, and the second curved surface is provided And a plurality of protrusions are provided.

  In the present invention, as the impeller rotates, a swirling flow is formed inside the duct housing around the direction of the rotational axis of the impeller, and the swirling direction of the swirling flow is opposite to the rotational direction of the impeller. And a structure that is

  The present invention comprises an impeller constituting a centrifugal fan, and a duct housing provided with a space for introducing a fluid to the impeller, wherein the duct housing includes an air inlet and an exhaust opening in a direction orthogonal to the rotation axis of the impeller. A port is provided, the impeller is positioned between the air inlet and the air outlet, a first curved surface and a second curved surface are provided inside the duct housing, and the first curved surface is The second curved surface is at a position sandwiching at least a part of a suction port for sucking the fluid to the inside of the impeller with respect to the first curved surface. The second curved surface may be provided with a plurality of protrusions.

  In the present invention, the second curved surface may have a structure closer to the intake port than the first curved surface. In the present invention, the second curved surface may have a structure not directed to the direction of the air inlet. In the present invention, a casing for housing the impeller is accommodated inside the duct housing, the casing is opened in the axial direction, and a suction port for sucking the fluid into the impeller is provided, and the first There is a structure in which at least a part of the suction port is located between the curved surface of the second and the second curved surface. In the present invention, the projection includes a rib structure extending in the direction of the rotation axis of the impeller.

  According to the present invention, even when sufficient space can not be secured in the vicinity of the side surface, a blower device having good air volume characteristics can be obtained.

It is a perspective view of a blower device using the present invention. It is a disassembled perspective view of the blower apparatus shown in FIG. It is a perspective view for demonstrating the position of the rib formed in the upper duct housing. FIG. 5 is a perspective view of a ribbed upper duct housing. The drawing substitute photograph (A) showing the flow velocity distribution of the swirling flow when the upper duct housing is not provided with ribs and the drawing substitution photo (B) showing the flow velocity distribution of the swirling flow when the upper duct housing is provided with ribs is there. It is sectional drawing of the blower apparatus shown in FIG. FIG. 2 is a perspective view of an impeller assembly. FIG. 5 is an exploded perspective view of an impeller assembly.

(1) Basic Structure Hereinafter, a basic structure of a blower apparatus 100 utilizing the present invention will be described with reference to FIGS. 1 to 3. The blower apparatus 100 has a centrifugal fan structure, and includes a blower 200 and a duct housing 300. The duct housing 300 is composed of an upper duct housing 301 covering one side of the blower 200, and a lower duct housing 303 integrally formed with the lower casing 202b, and the duct housing 300 has an inlet 304 formed therein. It is done. The upper duct housing 301 and the lower duct housing 303 are formed by resin molding.

  As shown in FIGS. 3 and 4, three ribs 307 are provided on the inner surface of the upper duct housing 301. The number of ribs 307 is not limited to three, but is preferably two or more. The rib 307 is a projection having a convex shape in cross section extending in the axial direction (direction of the rotation axis of the impeller 201). The rib 307 is formed at a portion where the swirling flow formed by the fluid (for example, air) flowing in from the intake port 304 substantially goes around and approaches the intake port 304.

  That is, the air flowing from the air inlet 304 into the internal space 310 of the upper duct housing 301 flows along the plane 301 a → the curved surface 301 b → the plane 301 c → the curved surface 301 d inside the upper duct housing 301 to form a swirling flow. Here, three ribs 307 are formed on the curved surface 301 d of a portion immediately before the swirling flow makes a round and return to the vicinity of the air inlet 304.

  That is, the curved surface 301 b is located opposite to the opening surface of the intake port 304 (the curved surface 301 b is at the back when the intake port 304 is viewed from the front), and the flow of air sucked into the internal space 310 from the intake port 304 The air sucked into the interior space 310 from the air inlet 304 strikes the curved surface 301 b and flows along the curved surface 301 b in the direction of the plane 301 c. The lower part of the plane 301 c is a curved surface 301 b, and the above-described air flows along the curved surface 301 b and flows back in the direction of the air inlet 304. As a result, when viewed from the viewpoint of FIG. 4B, a flow of air (turning flow in a left turn) that turns in a counterclockwise direction is generated. In the case of the viewpoint of FIG.

  As shown in FIG. 2, the upper casing 202 a is accommodated inside the upper duct housing 301, and the upper casing 202 a is provided with a suction port 203 for sucking air into the impeller 201. The air flowing into the upper duct housing 301 from the air inlet 304 flows into the impeller 201 from the air inlet 203 while forming the above-described swirling flow.

  The blower 200 is a centrifugal fan, and includes an impeller 201 having a large number of blades in the circumferential direction, a spiral casing 202 for housing the impeller 201, and a motor for rotating the impeller 201. The motor is disposed behind the impeller 201 in FIG. 2 and can not be seen in FIGS.

  The spiral casing 202 includes an upper casing 202a and a lower casing 202b which are formed by resin molding, and the upper casing 202a is formed with a suction port 203 opened in the rotational axis direction. Further, an exhaust port 305 is formed in the casing 202 in a direction orthogonal to the rotation axis. The spiral casing 202 is configured by combining two members (upper casing 202 a and lower casing 202 b) at the exhaust port 305.

  The lower casing 202 b is integrally molded with the lower duct housing 303 by resin molding, and is formed of the same member as the lower duct housing 303. The upper casing 202a and the lower casing 202b are each formed with a recess and a protrusion on their mating surfaces, and are coupled by engaging the protrusion with the recess to form the casing 202. In the present embodiment, a convex portion is formed on the mating surface of the upper casing 202a, and a concave portion is formed on the mating surface of the lower casing 202b.

  At the upper casing 202a, one fixing attachment leg 204 is formed, and at the lower casing 202b, two fixing attachment legs 205 are integrally formed. The fixing of the blower device 100 to the mounting base or the housing is performed by inserting a bolt into the through holes formed in the mounting legs 204 and 205 and using the bolt.

  The tongue portion 206 is formed on the inner peripheral surface of the spiral casing 202 in which the upper casing 202a and the lower casing 202b are joined, and the curved surface of the inner peripheral surface (inner peripheral wall) of the casing 202 starts from the tongue portion 206 It is formed of an involute curve.

  The impeller 201 is accommodated in a casing 202 constituted by the upper casing 202a and the lower casing 202b. As shown in FIG. 7, the impeller 201 is composed of a hub 21, a connecting portion 22 and blades 23. A large number of blades 23 are disposed in the circumferential direction with forward blades.

  Since the curved surface of the inner peripheral surface (inner peripheral wall) of the casing 202 is an involute curve starting from the tongue portion 206, the gap 309 between the inner peripheral surface (inner peripheral wall) of the casing 201 and the outer peripheral edge of the impeller 201 (See FIG. 3) gradually increases from the tongue 206 toward the exhaust port 305. The gap 309 has a minimum dimension of the gap of the tongue portion 206 when viewed from the viewpoint of FIG. 3, and the cross-sectional area gradually increases from the tongue portion 206 toward the exhaust port 305 in the counterclockwise direction. It constitutes a road.

  In this example, the lower casing 202a is integrally formed with the lower duct housing 303 by resin molding, and is formed of one member. This is because the upper and lower molds (upper and lower molds) can be easily integrally molded. On the other hand, the upper casing 202a is formed of a separate member from the upper duct housing 301. This is because it is necessary to form the suction port 203 opened in the axial direction in the upper casing 202a, so that resin molding can not be easily performed with the upper and lower molds (upper mold and lower mold). Although the upper casing 202a and the upper duct housing 301 can be integrally formed as one piece, a split mold is required, and the molding process becomes complicated, resulting in an increase in cost.

  When the impeller 201 rotates, air is drawn in from the air inlet 304, and this air swirls inside the duct housing 300 to form a swirling flow, and is sucked into the casing 202 from the air inlet 203. The air drawn in from the suction port 203 is blown radially outward from the outer periphery of the impeller 201, passing from the inner side of the impeller 201 between the blades, and the gap 309 in FIG. It is pumped in the clockwise direction and finally exhausted from the exhaust port 305.

(2) Motor Unit FIGS. 6 and 8 show a motor assembly 400 that constitutes the motor unit. The motor assembly 400 constitutes an inner rotor type motor. The motor assembly 400 includes a resin motor housing 401, a metal bracket 402, a stator 403, a rotor 406, and a circuit board 407. The stator 403 includes a stator core 404 and a coil 405 wound around a salient pole of the stator core 404 via a resin insulator 414. The stator core 404 is configured by laminating a predetermined number of soft magnetic cores, and the insulators 414 are attached from both axial sides, respectively, and the coil 405 is wound around the salient poles extending radially inward via the insulators 414. ing.

  The metal bracket 402 (see FIG. 8) includes a cylindrical portion 402a and a flange portion 402b extending radially outward of one end of the cylindrical portion 402a. A stator 403 is disposed inside the cylindrical portion 402 a of the metal bracket 402. Further, a metal bracket 402 is attached to a resin motor housing 401. The circuit board 407 is disposed on the rear end side of the shaft 408 serving as the rotation shaft, and is mounted on the motor housing 401 with a screw or the like. The back of the circuit board 407 is covered by a motor cover 308.

  The rotor 406 includes a metal shaft 408, a metal sleeve 409 fitted to the shaft 408, and a hollow cylindrical magnet 410 mounted on the outer periphery of the sleeve 409. The rotor 406 is disposed inside the stator 403 and rotatably supported by the motor housing 401 by a pair of bearings 411 and 412 mounted on the motor housing 401.

(3) Impeller assembly FIG. 7 shows the impeller assembly 500, and FIG. 8 shows the impeller assembly 500 disassembled. The impeller assembly 500 is composed of a motor assembly 400 and an impeller 201. The impeller assembly 500 is obtained by mounting the impeller 201 on the distal end side of the shaft 408 of the motor assembly 400 and fixing the impeller 201 to the shaft 408 by means of the stop washers 413.

  An impeller assembly 500 constituted by the motor assembly 400 and the impeller 201 is mounted on the lower casing 202b, as shown in FIG. This mounting is performed by inserting the motor assembly 400 from the inside of the lower casing 202b into the opening formed in the lower casing 202b and fixing the motor assembly 400 to the lower casing 202b with a screw or the like.

  The impeller assembly 500 in which the impeller 201 is attached to the motor assembly 400 can be attached to the lower casing 202b in a state in which the impeller 201 is attached. Therefore, unbalance of the impeller 201 can be adjusted in a state where the impeller 201 is attached to the motor assembly 400 in advance.

(4) Description As described above, the blower apparatus 100 has the duct housing 300 provided with the impeller 201 constituting the centrifugal fan and the internal space 310 for guiding the fluid to the impeller 201. An intake port 304 and an exhaust port 305 opened in a direction orthogonal to the rotation axis of the impeller 201 are provided, the impeller 201 is positioned between the intake port 304 and the exhaust port 305, and the first duct housing 300 is provided. A curved surface 301b which is a curved surface and a curved surface 301d which is a second curved surface are provided, and as the impeller 201 rotates, a swirling flow is formed inside the duct housing 300 with the direction of the rotation axis of the impeller 201 as an axis. Is located on the downstream side of the swirling flow of the curved surface 301b, and a plurality of projections 307 are provided on the curved surface 301d. It is broken.

  In addition, the blower apparatus 100 has a duct housing 300 provided with an impeller 201 constituting a centrifugal fan and an internal space 310 for guiding a gas to the impeller 201. The duct housing 300 has a direction orthogonal to the rotation axis of the impeller 201. An intake port 304 and an exhaust port 305 are provided, and the impeller 201 is positioned between the intake port 304 and the exhaust port 305. Inside the duct housing 300, a curved surface 301b as a first curved surface and a second curved surface are formed. A curved surface 301d which is a curved surface is provided, the curved surface 301b is at a position facing the opening surface of the air inlet 304, and the curved surface 301d is at least a part of the air suction inlet 203 to the inside of the impeller 201 with respect to the curved surface 301b. And a plurality of protrusions 307 are provided on the curved surface 301 d.

  Further, the curved surface 301 d is located closer to the intake port 304 than the curved surface 301 b, and the curved surface 301 d does not face in the direction of the intake port 304.

  By setting the positions of the inlet 304, the curved surface 301b, the curved surface 301d, the impeller 201, the inlet 203, and the protrusion 307 in the above-described relationship, the swirling flow to the inside of the duct housing 300 by the flow of air taken in from the inlet 304 Is formed. In addition, a phenomenon in which a portion where the flow velocity of the swirling flow is high is concentrated locally is inhibited by the projection 307, and the swirling flow is suppressed by the projection 307, and the air flowing into the suction port 203 of the impeller 201 is Relative speed decreases. For this reason, the resistance to which the air drawn in from the suction port 203 to the inside of the impeller 201 is reduced, and the generation of noise is suppressed.

(5) Features By joining the upper duct housing 301 and the lower duct housing 303, the intake port 304 is formed in the direction orthogonal to the rotation axis. The intake port 304 is in a positional relationship with the exhaust port 305 in the opposite direction (180 °). As a result, even if there is not a sufficient space in the vicinity of the suction port 203 disposed on the side surface of the blower device 100, the blower device 100 can be obtained that can ensure air volume characteristics and can blow air. .

  Further, a plurality of protrusions (ribs) 307 are formed in a portion of the upper duct housing 301 inside the lower portion of the air intake port 304. When the flow of the swirling flow sucked into the suction port 203 collides with the projection (rib) 307, the generation of the swirling flow sucked into the suction port 203 is suppressed, and the relative velocity of the air flowing into the suction port 203 decreases. . For this reason, the air volume characteristic is improved and the noise is improved.

  As shown in FIG. 2, the upper casing 202 a is covered by the upper duct housing 301. The bonding between the upper duct housing 301 and the upper casing 202a is performed by forming a step on the bonding surface of each other, and combining the steps. Similarly, in the bonding of the upper duct housing 301 and the lower duct housing 303, a step is formed on the bonding surface of each other, and they are bonded by aligning the steps.

  By joining the upper duct housing 301 and the lower duct housing 303, an air inlet 304 is formed in the direction orthogonal to the rotation axis. The intake port 304 is in a positional relationship with the exhaust port 305 in the opposite direction (180 °). A part of the curved surface of the inner circumferential surface (inner circumferential wall) continuing from the air inlet 304 of the duct housing 300 is on the extension of the involute curve starting from the tongue portion 206.

  The air taken in from the air inlet 304 of the duct housing 300 with the rotation of the impeller 201 is guided along the inner circumferential wall continuing from the air inlet 304 of the duct housing 300 to the air inlet 203 of the upper casing 202a.

  Although the gap between the inner circumferential wall continuing from the air inlet 304 of the duct housing 300 and the casing 202 gradually decreases, the sloped area 306 is provided in the closing region so that the gap becomes the smallest and there is no place to close. . For this reason, the air sucked from the air inlet 304 of the duct housing 300 is guided along the inner peripheral wall continuing from the air inlet 304, and then smoothly flows in the direction of the upper casing 202a by the inclined portion 306 and is guided to the air inlet 203 Be done.

  If there is no inclined portion 306 and there is a place where the gap is minimized and there is a blockage, this place becomes a dead water area (dead space), and an air vortex occurs at this place, and the air flow resistance increases. There is a problem of reduced efficiency.

  Further, in the present embodiment, the provision of the projecting portion 307 in FIG. 4 achieves an improvement in air volume characteristics and a reduction in noise. In the following, the provision of the protrusion 307 improves the air volume characteristics and reduces noise.

  In the present embodiment, when viewed from the axial direction, the air inlet 304 of the duct housing 300 is offset from the air inlet 203. For this reason, the air which flows in from the inlet 304 becomes a flow of air biased with respect to the inlet 203, and a swirling flow is thereby generated.

  Here, when viewed from the viewpoint of FIG. 3, the impeller 201 (see FIG. 2) rotates left, but the swirling flow generated by the flow of air entering the duct housing 300 from the inlet 304 is right rotation. Therefore, in the vicinity of the suction port 203, the swirling flow turning to the right flows into the inside of the impeller 201 rotating to the left, and the relative velocity of the air flow to the impeller 201 becomes large. The increase in the relative velocity increases as the velocity of the swirling flow increases when the rotation conditions of the impeller 201 are constant. The increase of the relative speed causes the reduction of the air volume characteristic of the blower device and the generation of noise.

  The result of having investigated the mode of the rotational flow in the duct housing 300 in case the projection part 307 is not provided by computer simulation is shown by FIG. 4 (A). As shown in FIG. 4A, the swirling flow formed in the duct housing 300 forms a fast-flowing portion in an annular portion around the pivoting center. Then, a portion on the right side of the portion where the annular flow velocity is high overlaps with the suction port 203 as viewed from the axial direction. The flow of air from the fast part of the flow to the inside of the impeller 201 rotating left by the viewpoint of FIG. 5 through the suction port 203 requires a rapid change of the flow direction. This increase in relative velocity to the impeller causes noise generation.

  The result of having investigated the mode of the rotational flow in the upper duct housing 301 in the case (protrusions of this embodiment) in which the projection part 307 is provided is shown by FIG. 4 (B) by computer simulation. A comparison of FIG. 4 (A) with FIG. 4 (B) shows that the portion with a high annular flow velocity (the portion in which the green color is displayed to indicate that the display density is high and the flow velocity is high) is shown. Although clearly visible in A), it is not visible in FIG. 4 (B). This is because, if there are a plurality of projections below the intake port 304 of the upper duct housing 301, the flow of the swirling flow is disturbed, the formation of a portion with a high flow velocity is suppressed, and the flow of air drawn into the suction port 203 Indicates that the relative velocity of is decreasing.

  By suppressing the formation of the portion where the flow velocity is high in the upper duct housing 301, the relative velocity of the air flow to the centrifugal fan of the above-mentioned right rotation ⇒ left rotation decreases, and the air volume characteristic of the blower device is reduced. Improve. In addition, since sudden changes in the direction of air flow can be suppressed, the generation of noise can be suppressed.

  Measurement of power consumption and noise (OA: overall) in the case where the protrusion 307 is not provided in the structure of FIG. 4 in (Table 1) (no protrusion) and in the case where the structure of FIG. 4 is adopted (this embodiment) Indicates a value.

  As can be seen from Table 1, the provision of the projections 307 can reduce power consumption and noise. The large power consumption indicates that the loss is large and the air volume characteristic is bad. From this, it is understood that the provision of the projection 307 can reduce the loss relating to the flow of air and can improve the air volume characteristic. Also, the ability to reduce noise means that the flow of air has become smoother and the influence of noise generation factors has been suppressed.

  The dimensions of the projection 307 are determined by the power of the motor, the size of the impeller 201, and the required air flow characteristics. As a projection part, the thing of the structure which divided the projection part 307 of FIG. 4 into multiple in the longitudinal direction is also employable. The protrusion is not limited to the protruding or projecting shape illustrated in FIG. 4, and uses a shape that blocks the flow of the swirling flow in front of the air inlet 304 so that a portion with high flow velocity is not formed. it can.

DESCRIPTION OF SYMBOLS 100 ... blower apparatus, 201 ... impeller, 21 ... hub, 22 ... connection part, 23 ... blade | wing, 202 ... casing, 202a ... upper casing, 202b ... lower casing, 203 ... suction port, 204 ... attachment leg, 205 ... attachment Leg 206 206 tongue 300 duct housing 301 upper duct housing 301 a flat surface 301 b curved surface 301 c flat surface 301 d curved surface 303 lower duct housing 304 air intake port 305 exhaust port , 306: a projection, 308: a motor cover, 309: a gap, 310: an internal space of the upper duct housing 301, 400: a motor assembly, 401: a motor housing, 402: a bracket, 403: a stator, 404 ... Stator core, 405 ... coil, 406 ... rotor, 407 ... circuit board, 4 8 ... shaft, 409 ... sleeve, 410 ... magnet 411 ... bearing, 412 ... bearing, 413 ... lock washer, 414 ... insulator, 500 ... impeller assembly.

Claims (7)

An impeller that constitutes a centrifugal fan,
And a duct housing provided with a space for introducing a fluid to the impeller.
The duct housing is provided with an inlet and an outlet that are open in a direction orthogonal to the rotation axis of the impeller.
The impeller is located between the air inlet and the air outlet,
A first curved surface and a second curved surface are provided inside the duct housing,
The blower apparatus provided with the several projection part in the said 2nd curved surface.   According to the rotation of the impeller, a swirling flow is formed inside the duct housing around the direction of the rotational axis of the impeller, and the swirling direction of the swirling flow is opposite to the rotational direction of the impeller. The blower apparatus as described in. An impeller that constitutes a centrifugal fan,
A duct housing provided with a space for introducing a fluid to the impeller;
The duct housing is provided with an inlet and an outlet that are open in a direction orthogonal to the rotation axis of the impeller.
The impeller is located between the air inlet and the air outlet,
A first curved surface and a second curved surface are provided inside the duct housing,
The first curved surface is at a position facing the opening surface of the intake port,
The second curved surface is located at a position sandwiching at least a part of a suction port for sucking the fluid to the inside of the impeller relative to the first curved surface,
The blower apparatus provided with the several projection part in the said 2nd curved surface.   The blower apparatus according to any one of claims 1 to 3, wherein the second curved surface is located closer to the intake port than the first curved surface.   The blower apparatus according to any one of claims 1 to 4, wherein the second curved surface is not directed in the direction of the air inlet. Inside the duct housing, a casing for housing the impeller is accommodated.
The casing is provided with an inlet that is axially open and sucks the fluid into the impeller.
The blower apparatus according to any one of claims 1 to 5, wherein at least a part of the suction port is located between the first curved surface and the second curved surface. The blower apparatus according to any one of claims 1 to 6, wherein the protrusion has a rib structure extending in the direction of the rotation axis of the impeller.

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