JP4935048B2 - Centrifugal fan - Google Patents

Description

  The present invention relates to an electric centrifugal fan used for blowing air.

  Conventionally, centrifugal fans that intake in the axial direction and exhaust in the radial direction are provided with an impeller having a plurality of blades arranged in the circumferential direction around the rotating shaft, making the centrifugal fan quieter and improving airflow characteristics And in order to suppress the performance fall accompanying the temperature rise of a motor, various devices are made | formed with respect to the impeller.

  For example, Patent Document 1 discloses a multiblade fan in which an inducer is connected to the inside of a blade, and guides an airflow flowing in from a suction port to the blade while suppressing the occurrence of turbulence by the inducer. A technique for reducing noise and improving fan efficiency is disclosed. Patent Document 2 discloses a sirocco having a general shape of the same size by combining the shape of a blade with a turbo fan and a sirocco fan. An impeller that can improve fan efficiency over a fan is disclosed.

  Further, in Patent Document 3, the impeller structure includes a plate-shaped airflow guide means that is perpendicular to the rotation axis inside the blade, and the airflow guide means is provided on the traveling path of the airflow to change the airflow pattern. A technique for reducing noise is disclosed, and Patent Document 4 discloses a technique in which an opening communicating with an air hole between blades is provided at the lower part of an impeller, and noise and current values when the impeller rotates can be reduced. It is disclosed.

Further, in Patent Document 5, a stay that supports the blades is provided from the middle of the cup portion at the center of the impeller so that the rotor hub is not covered with the cup portion of the impeller, so that the air suction port of the small sirocco fan is provided. A technique that can suppress an increase in noise due to a decrease in air flow characteristics due to a decrease in area and an increase in the number of revolutions of a motor is disclosed. A technique for cooling the armature by supplying air to the armature of the outer rotor motor housed in the through hole as an air passage is disclosed.
JP 2002-70793 A JP 2005-69183 A Utility Model Registration No. 3029287 Utility Model Registration No. 3101660 Japanese Patent Laid-Open No. 7-111756 Japanese Utility Model Publication No. 50-133511

  By the way, in a centrifugal fan in which an impeller having a cup portion for housing a motor in the center portion is used, air turbulence tends to occur near the outer surface of the cup portion, and the turbulence flows away from the cup portion to the outside. If it flows into the blades arranged in the direction, the noise of the centrifugal fan will increase. In addition, since air is not easily supplied to the inside of the cup portion, heat generated by the armature stored in the cup portion is accumulated, and it is important to suppress the temperature rise of the armature.

  The present invention has been made in view of the above problems, and has as its main purpose to reduce noise in a centrifugal fan having a cup portion in the center for housing an armature, and further efficiently supplies air to the armature. The purpose is to suppress the temperature rise of the armature.

The invention according to claim 1 is a centrifugal fan, which is fixed to a substantially bottomed cylindrical cup portion having a cylindrical yoke portion centering on a predetermined central axis, and an inner surface of the cup portion. A field magnet and a blade assembly connected to the cup portion and radially disposed in an annular region outside the cup portion, and rotating from the bottom side of the cup portion by rotating together with the cup portion An impeller part for taking in air and discharging the air in a direction away from the central axis; a side wall part covering the outer periphery of the impeller part; a base part covering the opening part side of the cup part; and the bottom part of the cup part A housing having a cover portion formed with an air inlet facing the housing, wherein a width of a flow path between the side wall portion and the impeller portion gradually widens toward the exhaust port, and the cup portion around the central axis To the base An armature that generates torque centered on the central axis between the bearing mechanism that is rotatably supported and at least a part of the bearing mechanism that is fixed to the base portion and is located in the cup portion. The blade assembly is disposed on the outer surface of the cup portion between the plurality of main wings arranged along the outer periphery of the impeller portion, and the outer surface of the cup portion and the plurality of main wings. A plurality of auxiliary wings that are connected and connected directly or indirectly to the plurality of main wings on the base portion side, and the edges of the plurality of auxiliary wings opposite to the base portion are outward. the length of the elongation while being inclined toward the base portion, the central axis direction of the central axis direction of width of the plurality of wings of the impeller portion in between said plurality of auxiliary blades and the plurality of wing 1/3 or less.

  The invention according to claim 2 is the centrifugal fan according to claim 1, wherein the impeller portion has a plurality of openings penetrating in the direction of the central axis between the plurality of auxiliary blades.

  The invention according to claim 3 is the centrifugal fan according to claim 2, wherein the base part side edges of the plurality of auxiliary blades extend outward from the opening of the cup part. The plurality of openings includes an opening end on the base portion side, and the plurality of main wing side portions of the opening end are located on the base portion side relative to the portion on the central axis side. Close to.

A fourth aspect of the present invention is the centrifugal fan according to any one of the first to third aspects, wherein ends of the plurality of main wings on the base portion side are connected by an annular plate centering on the central axis. The outermost part of the plurality of auxiliary wings is connected to the inner part of the annular plate.

A fifth aspect of the present invention is the centrifugal fan according to any one of the first to fourth aspects, wherein each of the plurality of auxiliary wings is continuous with one of the plurality of main wings.

  In the present invention, it is possible to reduce the noise of the centrifugal fan by suppressing the turbulent flow caused by the air flowing near the outer surface of the cup portion by the auxiliary blade. According to the second aspect of the present invention, air can be supplied to the armature by the auxiliary wing and the opening between them, and the temperature rise of the armature can be suppressed. In the third aspect of the invention, the air flowing toward the armature can be suppressed. Supply efficiency can be improved. In the invention of claim 4, the generation of turbulent flow can be efficiently suppressed. In the invention of claim 6, the rigidity of the impeller portion can be improved.

  FIG. 1 is a diagram showing a configuration of a centrifugal fan 1 according to an embodiment of the present invention, and shows a longitudinal section cut along a plane including a central axis J1. FIG. 2 is a plan view showing the centrifugal fan 1. However, in FIG. 1, illustration of the edge part of the housing 10 is abbreviate | omitted on both right and left sides, and FIG. 2 shows the state which removed the cover part (it is attached | subjected the code | symbol 111 in FIG. 1) of the housing 10 upper surface. ing. As shown in FIGS. 1 and 2, the centrifugal fan 1 is connected to the impeller unit 2 that generates an air flow by rotating, and the impeller unit 2 rotates around the predetermined central axis J <b> 1. The impeller unit 2 and the motor 3 are housed in the housing 10. The centrifugal fan 1 is used, for example, as an electric fan for air-cooling electrical products and electronic devices.

  As shown in FIG. 1, the housing 10 includes a cover portion 111 in which an intake port 12 serving as an air intake port is formed, and a base portion 112 to which a stator portion 31 to be described later is attached. Thus, the side wall part 113 which covers the outer periphery of the impeller part 2 is provided. The housing 10 is assembled by attaching the cover portion 111 to the housing main body 11 including the base portion 112 and the side wall portion 113 shown in FIG. 2, and an air flow path is formed by the housing 10 surrounding the impeller portion 2. (That is, the flow of air generated by the rotation of the impeller portion 2 is adjusted by the housing 10 and sent out). The width of the flow path between the side wall portion 113 and the impeller portion 2 is formed so as to gradually widen toward the exhaust port 13 (see FIG. 2), and the base 10 and the side wall portion 113 are blocked in the housing 10. Yes.

  As shown in FIG. 1, the motor 3 is an outer rotor type motor, and includes a stator portion 31 that is a fixed assembly and a rotor portion 32 that is a rotating assembly. The rotor portion 32 includes a bearing mechanism described later. Thus, the stator part 31 is supported so as to be rotatable about the central axis J1. In the following description, for convenience, the rotor part 32 side is described as the upper side and the stator part 31 side is the lower side along the central axis J1, but the central axis J1 does not necessarily coincide with the direction of gravity.

  The stator portion 31 is fixed to the base portion 112 which is the lower surface of the housing 10, and a cylindrical portion formed in the central portion of the base portion 112 has a substantially cylindrical shape centered on the central axis J <b> 1. A bearing holding portion 311 that protrudes upward from 112 (that is, the rotor portion 32 side) is attached. Ball bearings 312 and 313 serving as a bearing mechanism are provided at the upper and lower portions in the direction of the central axis J1 inside the bearing holding portion 311, and a preload spring 314 is provided below the ball bearing 313.

  The stator portion 31 is also fixed to the outer periphery of the bearing holding portion 311 (that is, fixed to the base portion 112 around the bearing holding portion 311), and the armature 315 and the base portion 112. And a circuit board 316 on which electronic components for current control to the armature 315 are mounted.

  The rotor portion 32 has a substantially bottomed cylindrical shape centered on the central axis J1, and the opening portion 3211 faces downward (that is, the opening portion 3211 faces the base portion 112). A substantially cylindrical field magnet 322 that is fixed to the inner surface and faces the armature 315, and protrudes downward from the bottom of the cup portion 321 (that is, a substantially disc-shaped portion at the upper end of the cup portion 321). A shaft 323 is provided.

  The shaft 323 is attached to the cup portion 321 by being press-fitted and fixed to a bush 324 fixed to the bottom portion of the cup portion 321, inserted into the bearing holding portion 311, and rotatably supported by ball bearings 312 and 313. The A locking member 3231 for locking the spring 314 is attached in the vicinity of the lower end of the shaft 323. Preload is applied to the ball bearing 313 by the spring 314, so that the shaft 323 and the ball bearings 312 and 313 are positioned at appropriate positions. Retained.

  In the centrifugal fan 1, the ball bearings 312 and 313 serve as a bearing mechanism that rotatably supports the cup portion 321 with respect to the base portion 112 around the central axis J 1, and the armature 315 is provided via the circuit board 316. The supplied drive current is controlled to generate torque (that is, rotational force) about the central axis J1 between the armature 315 and the field magnet 322, so that the shaft 323 together with the cup portion 321 and The impeller part 2 having the blade assembly 22 connected to the cup part 321 rotates around the central axis J1. The shaft 323 may be directly attached to the cup portion 321 without using the bush 324.

  In the centrifugal fan 1, the opening 3211 side of the cup portion 321 is covered by the base portion 112, and the inside of the cup portion 321 includes a cylindrical yoke portion 321a having a central axis J1 as a center, and a substantially bottomed cylindrical yoke member. 3212. The yoke member 3212 is made of a magnetic metal, and a field magnet 322 is attached to the inner surface of the yoke portion 321a, and a bush 324 is attached to the center of the bottom thereof. The outer side of the cup part 321 is a substantially bottomed cylindrical outer cup part 3213 made of resin, and is molded integrally with the entire impeller part 2, and the yoke member 3212 is press-fitted and fixed. The structure of the cup part 321 is not limited to the structure of FIG. 1. For example, the yoke member 3212 may be cylindrical, and the outer cup part 3213 may be connected to the shaft 323 or the bush 324. 3213 may be omitted and the impeller portion 2 may be directly connected to the opening of the yoke member 3212.

  FIG. 3 is a perspective view showing the impeller portion 2 and the outer cup portion 3213 formed integrally with the impeller portion 2. As shown in FIGS. 1 to 3, the impeller portion 2 includes blade assemblies 22 arranged radially in an annular region (centered on the central axis J <b> 1) outside the cup portion 321. In the centrifugal fan 1, when the impeller portion 2 rotates together with the cup portion 321, air is taken in from the intake port 12 facing the upper side of the impeller portion 2 (that is, the bottom side of the cup portion 321) and leaves the central axis J <b> 1. The air is discharged in the direction, and the air is guided to the exhaust port 13 along the side wall portion 113 as described above.

  The wing assembly 22 includes a plurality of main wings 221 arranged along the outer periphery of the impeller portion 2 while being spaced from the outer surface 321b of the cup portion 321 (the outer cup portion 3213), and the outer surface 321b of the cup portion 321. And a plurality of auxiliary wings 222 arranged between the cup portion 321 and the plurality of main wings 221. In FIG. 2, the tip of the main wing 221 is hidden except for a part, but each of the plurality of main wings 221 is a forward wing inclined toward the rotation direction 51 of the impeller 2 while moving outward. The plurality of main wings 221 are connected by an annular plate 23 having a lower end on the base portion 112 side perpendicular to the central axis J1 and centering on the central axis J1, and an upper end connected by an annular connecting portion 24. Molded. In FIG. 2, a part of the connecting portion 24 is deleted to show the shape of the main wing 221 (the same applies to FIGS. 4 to 7).

  As shown in FIG. 2, each of the plurality of auxiliary wings 222 is a reverse wing that faces outward and is inclined to the opposite side to the rotation direction 51 of the impeller portion 2, and is outside the outer cup portion 3213 of the cup portion 321. While being connected to the side surface 321 b, the outermost part of the auxiliary wing 222 is connected to the inner part of the annular plate 23. As shown in FIGS. 1 and 2, the auxiliary wings 222 are directly connected to one main wing 221 every two main wings 221 on the base portion 112 side, and each of the plurality of auxiliary wings 222 includes a plurality of auxiliary wings 222. It is continuous with one of the main wings 221. Thereby, the site | part between the main wing | blade 221 and the auxiliary wings 222 functions as a rib, and also the auxiliary wings 222 themselves function as a rib, and the rigidity of the impeller part 2 is improved.

  In particular, when the impeller portion 2 is molded from resin, the main wing 221 and the auxiliary wing 222 are connected to each other while using the annular plate 23 on the base portion 112 side to form the impeller portion 2 (resin injection or gold And the like can be easily removed from the mold. Of course, if there is no problem in the rigidity and molding of the impeller portion 2, the main wing 221 and the auxiliary wing 222 are separated and the plurality of auxiliary wings 222 are indirectly connected to the plurality of main wings 221 via the annular plate 23. May be. The auxiliary blade 222 may be connected to the outer surface of the yoke member 3212 (see FIG. 1) by insert molding or the like.

  By the way, in the blade assembly 22, it is preferable that the main wing 221 and the auxiliary wing 222 are continuous from the viewpoint of smoothly flowing air from the auxiliary wing 222 to the main wing 221. On the other hand, the air inflow efficiency into the main wing 221 can be improved when there is no obstacle between the cup portion 321 and the main wing 221. Therefore, the centrifugal fan 1 is designed such that the main wing 221 and the auxiliary wing 222 are made continuous and the width of the impeller portion 2 in the direction of the central axis J1 between the main wing 221 and the auxiliary wing 222 is small. Thus, it is possible to reduce the influence of the auxiliary blades 222 on the characteristics (for example, static pressure-air volume characteristics) of the centrifugal fan 1 due to the airflow generated in the main blades 221 while obtaining the turbulent flow suppressing effect of the auxiliary blades 222. it can. As a specific preferable design condition, the width in the direction of the central axis J1 of the impeller portion 2 between the plurality of main wings 221 and the plurality of auxiliary wings 222 (indicated by a symbol W in FIG. 1) is the plurality of main wings 221. 1/3 or less of the length in the direction of the central axis J1 (labeled L). Further, since the turbulent flow area is widened near the lower portion of the outer surface by the air flowing on the outer surface of the cup portion 321, in the centrifugal fan 1, as shown in FIG. The edge 2222 is inclined toward the base portion 112 while extending outward from the outer surface 321b of the cup portion 321, and the width of the auxiliary wing 222 in the direction of the central axis J1 is such that the cup portion 321 extends from the outer peripheral side of the impeller portion 2. It is gradually increased toward. As a result, generation of turbulent flow is efficiently suppressed without deteriorating fan characteristics.

  The width of the impeller portion 2 between the main wing 221 and the auxiliary wing 222 in the direction of the central axis J1 is one main wing 221 and one auxiliary wing 222 when the main wing 221 and the auxiliary wing 222 are directly connected. (That is, when attention is limited to an annular substantially concave region centered on the central axis J1 between the plurality of main wings 221 and the plurality of auxiliary wings 222, This is the vertical width of the rib-like portion in the annular region.) When the main wing 221 and the auxiliary wing 222 are indirectly connected via the annular plate 23, the thickness of the annular plate 23 is obtained.

  Further, as shown in FIGS. 1 to 3, the impeller portion 2 is provided with a plurality of openings 25 penetrating in the direction of the central axis J <b> 1 between the plurality of auxiliary blades 222. As shown in FIG. 1, the opening ends on the base portion 112 side of the plurality of openings 25 include the edges 2221 on the base portion 112 side of the plurality of auxiliary wings 222, and the portions 251 on the plurality of main wings 221 side of the opening ends (that is, A portion on the inner side of the annular plate 23) is closer to the base portion 112 than a portion 252 on the central axis J1 side (that is, a portion on the opening 3211 side of the cup portion 321). As a result, the open end is inclined toward the gap between the armature 315 and the circuit board 316. In order to incline the opening end, the edge 2221 of the auxiliary wing 222 on the base portion 112 side is inclined toward the base portion 112 while extending outward from the opening portion 3211 of the cup portion 321.

  While the structure of the centrifugal fan 1 has been described above, the centrifugal fan 1 is connected to the outer surface 321b between the outer surface 321b of the cup portion 321 and the main wing 221 and directly connected to the main wing 221 on the base portion 112 side. Since a plurality of auxiliary wings to be connected are provided (may be indirectly connected via the annular plate 23), the air flowing near the outer surface 321b of the cup portion 321 is swept by the auxiliary wings 222. The air can be smoothly and smoothly guided to the main wing 221. As a result, the occurrence of turbulent flow in the vicinity of the outer surface 321b of the cup portion 321 can be suppressed, air can smoothly flow to the main wing 221 and the noise of the centrifugal fan 1 can be reduced.

  Further, in the centrifugal fan 1, since at least a part of the armature 315 is located in the cup portion 321, heat generated in the armature 315 is easily trapped when the motor 3 rotates. Since an opening 25 penetrating in the direction of the central axis J1 is provided between the two, a part of the air flowing along the outer side surface 321b of the cup part 321 also flows into the cup part 321 (a region where air flows out from the cup part 321) In addition, the air flow is generated in the vicinity of the opening 25 by the auxiliary blade 222, so that the air can be efficiently sent into the cup portion 321. Air can be supplied to the armature 315 to suppress the temperature rise. Although depending on the design conditions, it has been confirmed that in the impeller portion where the opening 25 is not provided, when the temperature of the armature 315 is about 115 ° C., the opening 25 is reduced to about 47 ° C.

  Further, the opening ends on the base portion 112 side of the plurality of openings 25 are inclined toward the armature 315 and the circuit board 316 (particularly, toward the gap between the armature 315 and the circuit board 316), so that the electric machine The supply efficiency of the air flowing toward the child 315 can be improved, and the circuit board 316 can be cooled.

  Next, various other shapes of the main wing 221 and the auxiliary wing 222 of the impeller portion 2 will be described. 4 to 9 are diagrams showing other examples of the impeller portion. In the impeller portion 2 shown in FIG. 2, each auxiliary wing 222 is a reverse wing, but the shape of the auxiliary wing is not limited to the reverse wing. For example, in the impeller portion 2a shown in FIG. 222a is a forward wing, and each auxiliary wing 222b of the impeller portion 2b shown in FIG. 5 is a radial wing extending linearly from the cup portion 321 in the radial direction. The main wings 221 of the impeller portion 2a and the impeller portion 2b are forward wings, similar to the impeller portion 2.

  When a comparative experiment of the noise values of the impeller portions 2, 2a, 2b and the impeller portion (not shown) of only the main wing 221 was performed, 54.1 dB (A), 55.2 dB (A), 54.8 dB ( A) and 55.8 dB (A). From this, it can be seen that when the main wing 221 is a forward blade in order to increase the static pressure of the fan, the noise value can be most reduced by using the auxiliary wing 222 as a backward blade. Even if the auxiliary wing is not a reverse wing, it can be said that noise is reduced by providing the auxiliary wing.

  On the other hand, the main wing is not limited to the forward wing as in the impeller portion 2 of FIG. 2, and may be, for example, a main wing 221a that is a radial wing like the impeller portion 2c shown in FIG. A main wing 221b that is a reverse wing may be used as in the impeller portion 2d shown in FIG.

  Further, in the blade assembly 22 of the impeller portion 2, one main wing 221 and one auxiliary wing 222 may be connected for every three or more main wings 221, and as in the impeller portion 2e shown in FIG. The auxiliary wings 222 may be continuously formed on the main wings 221. Further, the shape of the auxiliary wings is not limited to a flat plate shape, and as shown in FIG. 9, when the impeller portion 2 f is viewed from the upper side, each auxiliary wing 222 c moves from the cup portion 321 to the outer peripheral side of the impeller portion 2 f. It may be curved while stretched.

  Further, as shown in FIG. 1, the connection range between the auxiliary wing 222 and the cup portion 321 is not only the range from the middle to the lower end of the outer surface 321b of the cup portion 321 in the direction of the central axis J1, but also as shown in FIG. The range from the upper end to the lower end of the cup portion 321, as shown in FIG. 11, the range from the middle to the middle of the outer surface 321 b in the direction of the central axis J <b> 1, from the upper end to the lower end of the cup portion 321 as shown in FIG. 12. It may be made the range. Further, the lower and upper edges 2221, 2222 of the auxiliary wing 222 may be curved as shown in FIG. 13, and the edges parallel to the upper edge 2222 and the central axis J1 as shown in FIGS. 2223 may be continuous.

  As described above, the shape, number, and size of the blades may be variously changed, and the main wing 221 and the auxiliary wing 222 may be changed based on the equipment on which the centrifugal fan 1 is mounted, the required airflow characteristics, and the like. The shape and the like are determined. In any of the main wings 221 and the auxiliary wings 222, generation of turbulent flow in the vicinity of the outer surface 321b of the cup portion 321 can be suppressed to reduce noise.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the said embodiment, A various change is possible.

  For example, the shape of the upper edge 2222 of the auxiliary wing 222 may be a shape in which a step is provided in the middle as shown in FIG. Further, as shown in FIG. 17, the edges 2221 of the plurality of auxiliary wings 222d extend horizontally from the opening 3211 of the cup portion 321 to the outside, so that the shapes of the plurality of auxiliary wings 222d are substantially triangular, and the plurality of auxiliary wings 222d The outermost part may be connected only to the inner part of the annular plate 23. Also in this case, generation of turbulent flow on the outer side surface 321b of the cup portion 321 can be suppressed to reduce noise, and an opening 25 is provided between two adjacent auxiliary blades 222d. By supplying air into the cup part 321 by the action of 25, the temperature rise of the armature 315 can be suppressed.

  In the embodiment described above, almost the entire armature 315 is accommodated in the cup portion 321. However, when the armature 315 is disposed in a recess formed around the central axis J1 of the base portion 112, the armature 315 is disposed. May be located in the cup portion 321. In addition to the ball bearing, a sleeve bearing or the like may be used as the bearing mechanism.

  The annular plate 23 does not need to be a plate perpendicular to the central axis J1, and for example, a cross section by a plane including the central axis J1 is inclined from a direction perpendicular to the central axis J1, such as a truncated cone-shaped inclined surface. Also good. In the above embodiment, air is supplied from the opening 25 to the armature 315. However, if the opening 25 does not need to be provided because the temperature rise of the armature 315 is within an allowable range, the opening 25 is It may not be provided.

It is sectional drawing which shows the structure of the centrifugal fan which concerns on one embodiment of this invention. It is a top view which shows a centrifugal fan. It is a perspective view which shows an impeller part. It is a top view which shows the other example of an impeller part. It is a top view which shows the other example of an impeller part. It is sectional drawing which shows the other example of an impeller part. It is sectional drawing which shows the other example of an impeller part. It is a top view which shows the other example of an impeller part. It is a top view which shows the other example of an impeller part. It is sectional drawing which shows the other example of an auxiliary wing. It is sectional drawing which shows the other example of an auxiliary wing. It is sectional drawing which shows the other example of an auxiliary wing. It is sectional drawing which shows the other example of an auxiliary wing. It is sectional drawing which shows the other example of an auxiliary wing. It is sectional drawing which shows the other example of an auxiliary wing. It is sectional drawing which shows the other example of an auxiliary wing. It is sectional drawing which shows the other example of an auxiliary wing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Centrifugal fan 2,2a, 2b, 2c, 2d, 2e, 2f Impeller part 10 Housing 12 Intake port 13 Exhaust port 22 Blade assembly 23 Annular plate 25 Opening 51 Rotation direction 111 Cover part 112 Base part 113 Side wall part 221,221a , 221b Main wings 222, 222a, 222b, 222c, 222d Auxiliary wings 312 and 313 Ball bearings 315 Armature 321 Cup part 321a Yoke part 321b Outer side face 322 Field magnet 2221, 2222 Edge 3211 Opening part J1 Central axis

Claims (5)

A centrifugal fan,
A substantially bottomed cylindrical cup portion having a cylindrical yoke portion centered on a predetermined central axis;
A field magnet fixed to the inner surface of the cup part;
The wing assembly is connected to the cup portion and radially arranged in an annular region outside the cup portion, and the center is formed by taking air from the bottom side of the cup portion by rotating together with the cup portion. An impeller for discharging the air in a direction away from the shaft;
A side wall portion covering the outer periphery of the impeller portion, a base portion covering the opening side of the cup portion, and a cover portion formed with an air inlet that faces the bottom portion of the cup portion; A housing in which the width of the flow path between the impeller portion gradually widens toward the exhaust port,
A bearing mechanism that rotatably supports the cup portion with respect to the base portion around the central axis;
An armature that is fixed to the base portion and at least a portion thereof is located in the cup portion and generates torque centered on the central axis with the field magnet;
With
The wing assembly is
A plurality of main wings arranged along the outer periphery of the impeller portion;
Between the outer surface of the cup portion and the plurality of main wings, a plurality of auxiliary members connected to the outer surface of the cup portion and connected directly or indirectly to the plurality of main wings on the base portion side With wings,
With
Edges of the plurality of auxiliary wings opposite to the base portion extend outward and are inclined toward the base portion, and the impeller portion between the plurality of main wings and the plurality of auxiliary wings The centrifugal fan, wherein a width in the central axis direction is 1/3 or less of a length in the central axis direction of the plurality of main wings. The centrifugal fan according to claim 1,
The centrifugal fan, wherein the impeller portion has a plurality of openings penetrating in the direction of the central axis between the plurality of auxiliary blades. The centrifugal fan according to claim 2,
Edges on the base part side of the plurality of auxiliary wings are inclined toward the base part while extending outward from the opening part of the cup part, and opening ends on the base part side of the plurality of openings The centrifugal fan including the edge, wherein the plurality of main wing side portions of the open end are closer to the base portion than the central axis side portion. The centrifugal fan according to any one of claims 1 to 3,
End portions on the base portion side of the plurality of main wings are connected by an annular plate centering on the central axis, and the outermost portion of the plurality of auxiliary wings is connected to the inner portion of the annular plate. A centrifugal fan characterized by that. The centrifugal fan according to any one of claims 1 to 4,
Each of the plurality of auxiliary wings is continuous with any one of the plurality of main wings.

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