JP4935051B2 - Centrifugal fan - Google Patents

Description

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

  Conventionally, in a centrifugal fan that sucks in an axial direction and exhausts in a radial direction, an impeller having a plurality of blades arranged in a circumferential direction around a rotating shaft is provided, and a cup provided at the center of the impeller A cylindrical metal magnet yoke having a magnetic field magnet on the inner surface is press-fitted and attached to the cylindrical portion, so that the impeller can be rotated around the rotation shaft. In such a centrifugal fan, various devices have been devised in order to reduce the noise, improve the air flow characteristics, and suppress the performance deterioration caused by the temperature rise of the motor.

For example, in Patent Document 1, the axial length of the inner surface of the casing is reduced to reduce the gap between the impeller and the side plate (the plate portion under the impeller), thereby realizing noise reduction, and at the same time, a step is formed on the side plate. A centrifugal fan is disclosed in which the flow path portion is thinned and the side plate is thinned to expand the flow path in the axial direction to improve the air flow characteristics. Moreover, in patent document 2, by providing the through-hole for external air suction | attraction in the top | upper surface (bottom surface) of the cup-shaped part of the impeller of an axial fan motor, cooling air is taken in from the through-hole at the time of impeller rotation, and an armature is installed. A technique for cooling and suppressing temperature rise of the axial fan motor is disclosed.
JP 2004-92489 A Japanese Utility Model Publication No. 61-113563

  By the way, in recent years, centrifugal fans for cooling have been rotating at high speed, and the motor current housed in the centrifugal fan increases with high-speed rotation, so the temperature rise of the armature and electronic components is ignored. It tends to increase so much that it cannot be done. In consideration of the demand for further high-speed rotation and the use of a centrifugal fan in a high-temperature environment, it is necessary to forcibly cool the armature and the electronic components.

  In the centrifugal fan of Patent Document 1, the armature is housed in the cup portion of the impeller, and the armature is disposed in the space formed by the housing and the cup, so that the temperature of the armature rises when the motor rotates. If this is the case, the generated heat cannot be released. Further, in the axial fan motor of Patent Document 2, it is difficult to increase the amount of cooling air supplied, and when the temperature of the armature is significantly increased, a cooling effect that is not expected can not be obtained.

  The present invention has been made in view of the above problems, and an object thereof is to efficiently supply air to an armature in a centrifugal fan and suppress an increase in temperature of the armature.

The invention according to claim 1 is a centrifugal fan, which is fixed to a substantially bottomed cylindrical cup part including a cylindrical yoke part centering on a predetermined central axis, and an inner surface of the cup part. A magnet for field, and a plurality of blades connected to the cup portion and arranged in an annular shape around the central axis outside the cup portion, and the cup portion by rotating together with the cup portion An impeller portion that takes in air from the bottom side of the nozzle and discharges the air in a direction away from the central axis, a side wall portion that covers the outer periphery of the impeller portion, a base portion that covers the opening side of the cup portion, and the cup A housing having an air inlet that is opposed to the bottom of the housing, wherein the width of the flow path between the side wall and the impeller gradually widens toward the exhaust port, and the center axis The cup part is Generating a torque centered on the central axis between the bearing mechanism that is rotatably supported with respect to the portion and at least a portion of the bearing mechanism that is fixed to the base portion and located within the cup portion. An armature, and a circuit board mounted between the armature and the base portion , wherein the base portion connects the plurality of blades on the base portion side, and the base portion. A concave portion that partially enlarges the gap between the ring plate and an annular convex portion that protrudes toward the connecting plate and forms the gap, and the upper surface of the concave portion in a direction parallel to the central axis is The circuit board is located below the top surface of the circuit board, and the top surface of the annular protrusion is located above the top surface of the circuit board .

  Invention of Claim 2 is the centrifugal fan of Claim 1, Comprising: The said side wall part is equipped with the delivery wall by the side of the said exhaust port, and the curved wall upstream from the said delivery wall, The concave portion enlarges the gap between the connecting plate and the base portion between the curved wall and the central axis in a range of 30 ° to 180 ° centering on the central axis.

  A third aspect of the present invention is the centrifugal fan according to the second aspect, wherein the base portion has the gap between the connecting plate and the base portion closer to the exhaust port than the concave portion. Another recess is further provided.

  Invention of Claim 4 is the centrifugal fan in any one of Claim 1 thru | or 3, Comprising: The said connection board is continuing to the said opening part of the said cup part, The said several wing | blade and the said The gap between the cup part is closed.

  A fifth aspect of the present invention is the centrifugal fan according to any one of the first to fourth aspects, wherein the base portion includes an annular convex portion that protrudes toward the connecting plate and forms the gap. The concave portion is provided in the annular convex portion.

The invention according to claim 6 is a centrifugal fan, which is fixed to a substantially bottomed cylindrical cup portion including a cylindrical yoke portion centering on a predetermined central axis, and an inner surface of the cup portion. A magnet for field, and a plurality of blades connected to the cup portion and arranged in an annular shape around the central axis outside the cup portion, and the cup portion by rotating together with the cup portion An impeller portion that takes in air from the bottom side of the nozzle and discharges the air in a direction away from the central axis, a side wall portion that covers the outer periphery of the impeller portion, a base portion that covers the opening side of the cup portion, and the cup A housing having an air inlet that is opposed to the bottom of the housing, wherein the width of the flow path between the side wall and the impeller gradually widens toward the exhaust port, and the center axis The cup part is Generating a torque centered on the central axis between the bearing mechanism that is rotatably supported with respect to the portion and at least a portion of the bearing mechanism that is fixed to the base portion and located within the cup portion. An armature, and a circuit board mounted between the armature and the base portion , wherein the base portion connects the plurality of blades on the base portion side, and the base portion. A concave portion that partially enlarges the gap between the ring plate and an annular convex portion that protrudes toward the connecting plate and forms the gap, and the upper surface of the concave portion in a direction parallel to the central axis is The circuit board is located below the top surface of the circuit board, and the top surface of the annular protrusion is located above the top surface of the circuit board .

The invention according to claim 7 is a centrifugal fan, and is fixed to a substantially bottomed cylindrical cup part including a cylindrical yoke part centering on a predetermined central axis, and an inner surface of the cup part. A field magnet and a plurality of wings extending radially from the outer surface of the cup part, and by rotating together with the cup part, air is taken in from the bottom side of the cup part and away from the central axis. An impeller part for discharging air, 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 a cover part formed with an air inlet facing the bottom part of the cup part A housing in which the width of the flow path between the side wall portion and the impeller portion is gradually widened toward the exhaust port, and the cup portion is rotatably supported with respect to the base portion around the central axis. A bearing mechanism; At least a portion is fixed to the over scan portion is positioned within said cup portion, and an armature that generates torque around the central axis between the field magnet, and the armature and the base portion A circuit board mounted between the base plate and the concave portion that partially enlarges the gap between the base plate and the connecting plate that connects the plurality of blades on the base portion side . An annular convex portion that protrudes toward the connecting plate and forms the gap, and the upper surface of the concave portion is located below the upper surface of the circuit board with respect to the direction parallel to the central axis, The upper surface of the annular convex portion is located above the upper surface of the circuit board .

  The invention according to claim 8 is the centrifugal fan according to claim 6 or 7, wherein the side wall includes a delivery wall on the exhaust port side and a curved wall on the upstream side of the delivery wall. The concave portion enlarges the gap between the opening and the base portion in the range of 30 ° to 180 ° centered on the central axis between the curved wall and the central axis.

  The invention according to claim 9 is the centrifugal fan according to claim 8, wherein the base portion has the gap between the opening and the base portion closer to the exhaust port than the recess. Another recess is further provided.

  A tenth aspect of the present invention is the centrifugal fan according to any one of the sixth to ninth aspects, wherein the base portion includes an annular convex portion that protrudes toward the opening and forms the gap. The concave portion is provided in the annular convex portion.

  The invention according to claim 11 is the centrifugal fan according to claim 2 or 8, wherein the recess is provided upstream from a position facing a boundary between the delivery wall and the curved wall.

  Invention of Claim 12 is the centrifugal fan of Claim 3 or 9, Comprising: The said recessed part is provided in the upstream rather than the position facing the boundary of the said delivery wall and the said curved wall, The said Another recess includes a position facing the boundary, or is provided downstream of the position.

The invention of claim 13 is a centrifugal fan according to any one of claims 1 to 12, with respect to a direction perpendicular to the front Symbol central axis, said recess between said circuit board and said armature Opposite the gap.

  In the present invention, air can be efficiently supplied to the armature, and the temperature rise of the armature can be suppressed. In the inventions of claims 3, 9 and 12, the air intake efficiency can be improved, and in the invention of claim 13, the temperature rise of the electronic component can be suppressed.

  FIG. 1 is a diagram showing a configuration of a centrifugal fan 1 according to a first embodiment of the present invention, and shows a longitudinal section cut along a plane including a central axis J1. FIG. 2 is an exploded perspective view showing the main configuration of the centrifugal fan 1. As shown in FIG. 1, the centrifugal fan 1 includes an impeller portion 2 that generates an air flow by rotating, and a motor 3 that is connected to the impeller portion 2 and rotates the impeller portion 2 around a central axis J1. The impeller unit 2 and the motor 3 are accommodated in the housing 10. As shown in FIGS. 1 and 2, the housing 10 is assembled by attaching a cover portion 12 having an intake port 121 to the housing body 11, and surrounds the impeller portion 2 to form an air flow path (that is, The air flow generated by the rotation of the impeller unit 2 is adjusted to send out the air). The centrifugal fan 1 is used, for example, as an electric fan for air-cooling electrical products and electronic devices.

  FIG. 3 is a plan view of the housing body 11 and the stator portion 31 described later in FIGS. 1 and 2. As shown in FIGS. 1 to 3, the housing main body 11 that is a part of the housing 10 includes a base portion 112 to which the stator portion 31 is attached and a side wall portion 113 that covers the outer periphery of the impeller portion 2. And the impeller portion 2 have a structure in which the width of the flow path gradually increases toward the exhaust port 13 (see FIG. 3). The side wall 113 includes a delivery wall 1131 on the exhaust port 13 side and a curved wall 1132 on the upstream side of the delivery wall 1131 (that is, a portion far from the exhaust port 13 along the inner surface of the housing body 11).

  In addition, in the centrifugal fan 1, the delivery wall 1131 is planar, and the curved wall 1132 is approximately cylindrical with the central axis J1 as the center, but the delivery wall 1131 may be curved to some extent. Also in this case, the (average) radius of curvature of the substantially flat plate-like portion corresponding to the delivery wall 1131 is made larger than the (average) radius of curvature of the curved wall 1132, and the flow is changed by the large change in the radius of curvature. The position where the road width starts to be greatly expanded can be specified as the boundary between the delivery wall and the curved wall (corresponding to the position indicated by reference numeral 1133 in FIG. 3). Further, as shown in FIGS. 2 and 3, in the vicinity of the exhaust port 13, in order to prevent the generated air flow from returning to the uppermost stream of the flow path, the impeller portion 2 and the base portion 112 A step portion 1134 for reducing the gap between the two is provided.

  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 that is the lower surface of the housing body 11 and holds each portion of the stator portion 31. The cylindrical portion formed in the central portion of the base portion 112 has a substantially cylindrical shape centered on the central axis J1 and a bearing holding portion 311 that protrudes upward from the base portion 112 (that is, the rotor portion 32 side). Is attached. Inside the bearing holding portion 311, ball bearings 312 and 313, which are part of the bearing mechanism, are provided at the upper and lower portions in the direction of the central axis J1, 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 fixed to the inner surface, and a shaft 323 projecting 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).

  The shaft 323 is press-fitted and fixed to the bottom of the cup portion 321, inserted into the bearing holding portion 311, and rotatably supported by ball bearings 312 and 313. A locking member 3231 that locks the spring 314 is attached in the vicinity of the lower end of the shaft 323, and 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 held at appropriate positions. The In the centrifugal fan 1, the shaft 323 and 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 <b> 1. The driving current supplied to the child 315 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 and The impeller part 2 attached to the cup part 321 rotates around the central axis J1 together with the cup part 321.

  As shown in FIGS. 1 and 2, the impeller portion 2 is connected to the cup portion 321 and arranged in an annular shape around the central axis J1 outside the cup portion 321 (away from the cup portion 321). The plurality of blades 22 and the lower opening 3211 on the lower side of the cup portion 321 are extended outward (that is, in a direction away from the central axis J1) and the plurality of blades 22 are disposed on the lower side (that is, the base portion 112 side). An annular connecting plate 23 to be connected is provided. The inside of the cup part 321 is a substantially bottomed cylindrical yoke member 3212 including a cylindrical yoke part 321a centering on the central axis J1, and the yoke member 3212 is formed of a magnetic metal, A field magnet 322 is attached to the inner surface of the yoke portion 321a and faces the armature 315. The outside 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. The structure of the cup part 321 is not limited to the structure of FIG. 1. For example, the yoke member 3212 may have a cylindrical shape, or the outer cup part 3213 is omitted as shown in FIG. It may be directly connected to the opening of the yoke member 3212.

  Each of the plurality of blades 22 extends from the upper surface of the connecting plate 23 (that is, the main surface on the bottom side of the cup portion 321) substantially parallel to the central axis J1, and the upper ends of the plurality of blades 22 are connected by the annular portion 24. The In the centrifugal fan 1, the base part 112 covers the opening part 3211 side of the cup part 321, the cover part 12 is formed with an air inlet 121 facing the bottom part of the cup part 321, and the impeller part 2 together with the cup part 321. By rotating, air is taken in from the inlet 121 and discharged in a direction away from the central axis J1. Then, air flows through the flow path between the impeller portion 2 and the side wall portion 113 and is guided to the exhaust port 13.

  As shown in FIGS. 1 to 3, the base portion 112 includes an annular convex portion 1121 that protrudes toward the coupling plate 23 of the impeller portion 2. As shown in FIG. A predetermined small gap 14 is formed between the portion 112. The size of the gap 14 is determined based on the shape accuracy and assembly accuracy so that the impeller portion 2 and the base portion 112 do not contact each other. When the gap between the connecting plate 23 and the base portion 112 is large, stagnation of the air flow occurs and the noise value of the centrifugal fan 1 increases, but in the centrifugal fan 1, the gap between the connecting plate 23 and the base portion 112. By reducing the noise level, the noise level is suppressed.

  However, if the gap 14 is reduced in order to reduce the noise value, the space formed by the cup portion 321 and the base portion 112 becomes close to a sealed state, and the armature 315 and the circuit board 316 are located in this space. The temperature of the armature 315 and the circuit board 316 will rise. Therefore, in the centrifugal fan 1, as shown in FIGS. 1 to 3, between the curved wall 1132 of the side wall 113 and the central axis J1, 30 ° to 180 ° (preferably 60 °) centering on the central axis J1. A recess 1122 that partially enlarges the gap 14 (see FIG. 1) in the range of 120 ° to 120 °, more preferably 80 ° to 100 ° is provided in the annular convex portion 1121. Further, from the viewpoint of efficiently supplying air to the armature 315, the recess 1122 is provided from the position facing the boundary 1133 (see FIG. 3) between the delivery wall 1131 and the curved wall 1132 toward the upstream side. Is preferred.

  In other words, in the fan-shaped region inside the curved wall 1132, the central axis J <b> 1 extends in the direction opposite to the rotation direction of the impeller portion 2 from the intersection position of the line segment connecting the boundary 1133 and the central axis J <b> 1 and the annular convex portion 1121. It is preferable that the concave portion 1122 is provided on the annular convex portion 1121 within a range of 30 ° to 180 ° centering on the annular convex portion 1121. The boundary between the annular convex portion 1121 and the concave portion 1122 is an inclined surface in which the height of the annular convex portion 1121 gradually decreases toward the concave portion 1122, and air is smoothly guided into the cup portion 321. In FIG. 3, a parallel oblique line is attached to the bottom region of the recess 1122.

  The recess 1122 reduces the degree of sealing of the space formed by the cup portion 321 and the base portion 112 in the centrifugal fan 1, and air is supplied to the stator portion 31 via the recess 1122 by the rotation of the impeller portion 2. The

  As described above, in the centrifugal fan 1, the base portion 112 is provided with the annular convex portion 1121 that protrudes toward the connecting plate 23 so as to reduce the gap 14, thereby suppressing the stagnation of the wind flowing through the gap 14. While reducing the noise value, a concave portion 1122 that enlarges the gap 14 is provided in a part of the annular convex portion 1121, whereby air is supplied to the space formed by the cup portion 321 and the base portion 112, and the electric machine The temperature rise of the child 315 can be reduced.

  In particular, in the direction perpendicular to the central axis J1, the recess 1122 faces the gap between the armature 315 and the circuit board 316, thereby efficiently supplying air to both the armature 315 and the circuit board 316. Temperature rise of electronic components mounted on the child 315 and the circuit board 316 can be suppressed. As a result, the impeller portion 2 of the centrifugal fan 1 can be rotated more quickly while improving the derating of the electronic component, and the air flow characteristics can be improved. Further, since the heat generation of the armature 315 is suppressed, the temperature rise near the bearing mechanism can be suppressed, and the lifetime of the centrifugal fan 1 can be extended.

  Further, in the centrifugal fan 1, the connecting plate 23 continues to the opening 3211 of the cup portion 321, and the space between the plurality of blades 22 and the cup portion 321 is closed so that the armature 315 is connected to the armature 315 from the inside of the blade 22. It is particularly preferable that the recess 1122 is provided in the base portion 112 because no air flow occurs. Note that the gap 14 can be reduced by increasing the height of the impeller portion 2 instead of providing the annular convex portion 1121, but if the plurality of blades 22 become unnecessarily long, the current value of the motor 3 increases. Therefore, when it is desired to suppress the power consumption while maintaining the air flow characteristic, it is preferable to provide the annular convex portion 1121 and provide the concave portion 1122 on the annular convex portion 1121.

  In the above structure, as the range of the recess 1122 is increased, the cooling efficiency of the armature 315 can be improved. However, simply expanding the recess 1122 may increase the noise value, so the recess 1122 is provided at a harmonious position and range that suppresses the noise value and the temperature rise of the armature 315. In which position and range the recess 1122 is provided depends on the shape of the impeller 2 and the housing 10, the required air volume and static pressure characteristics, and the design of the recess 1122 is appropriately changed according to the application of the centrifugal fan 1. The

  5 and 6 are plan views showing other preferable examples of the housing main body 11. In FIGS. 5 and 6 as well, parallel oblique lines are given to the bottom area of the recess 1122 as in FIG. In the example shown in FIG. 5, a concave portion that enlarges the gap 14 (see FIG. 1) toward the upstream side from a position on the annular convex portion 1121 that is substantially opposite to the boundary 1133 between the delivery wall 1131 and the curved wall 1132 of the side wall portion 113. 1122 is provided on the annular convex portion 1121, and its range is 180 ° centered on the central axis J1. Thereby, air is supplied to the stator part 31 (refer FIG. 3) from a wider range.

  Further, in the example shown in FIG. 6, the concave portion 1122 is an annular convex portion from the upstream side to the upstream side from the position on the annular convex portion 1121 facing the boundary 1133 between the delivery wall 1131 and the curved wall 1132 of the side wall portion 113. 1121 and its range is 90 ° centered on the central axis J1. Since the pressure generally increases on the upstream side, in the example shown in FIG. 6, air can be efficiently guided to the armature 315 by providing the concave portion 1122 on the upstream side.

  In the examples of FIGS. 3, 5, and 6, the position of the recess 1122 can be generally expressed as a position on the opposite side of the exhaust port 13. By providing the recess 1122 in this way, the position can be efficiently obtained. Air is supplied to the armature 315. The air supplied from the recess 1122 flows out of the gap 14 on the downstream side and travels toward the exhaust port 13.

  Next, a centrifugal fan according to a second embodiment of the present invention will be described. The centrifugal fan according to the second embodiment is provided with a housing body 11a shown in a plan view of FIG. 7 in place of the housing body 11 shown in FIGS. This is the same as the centrifugal fan 1. FIG. 8 is a perspective view of the housing body 11a. In FIGS. 7 and 8, the same components as those of the centrifugal fan 1 are denoted by the same reference numerals.

  As shown in FIGS. 7 and 8, the base portion 112 of the housing main body 11a is connected to the connecting plate 23 and the base on the upstream side of the position on the annular convex portion 1121 facing the boundary 1133 between the delivery wall 1131 and the curved wall 1132. A recess 1122a that enlarges the gap 14 (see FIG. 1) between the connecting portion 23 and the base portion 112 is provided on the exhaust port 13 side of the recess 1122a. A recess 1122b is provided. In FIG. 7, as in FIG. 3, the regions of the recesses 1122a and 1122b are indicated by parallel oblique lines.

  The concave portion 1122b is provided so as to include a position on the annular convex portion 1121 facing the boundary 1133 between the delivery wall 1131 and the curved wall 1132, and air is taken in from the concave portion 1122a on the upstream side where the air pressure is increased. Air supplied from 1122b to the stator portion 31 (see FIG. 3) is discharged. Thereby, air can be taken into the armature 315 efficiently. Note that the recess 1122b may be provided on the downstream side of the position facing the boundary 1133.

  FIG. 9 is a longitudinal sectional view of a centrifugal fan 1a according to the third embodiment of the present invention. The centrifugal fan 1a is largely different from the centrifugal fan 1 of FIG. 1 in that the plurality of blades 22a extend radially from the outer surface of the cup portion 321. That is, the centrifugal fan 1 in FIG. 1 is a so-called sirocco fan, while the centrifugal fan 1a in FIG. 9 is a so-called turbo fan. Further, in the centrifugal fan 1 a, the annular convex portion 1121 of the base portion 112 is provided so as to protrude toward the opening portion 3211 (the edge thereof) of the cup portion 321, and between the opening portion 3211 of the cup portion 321 and the base portion 112. A concave portion 1122 that partially enlarges the gap is provided in the annular convex portion 1121. Other structures are the same as those of the centrifugal fan 1 of FIG.

  In the case of the centrifugal fan 1a shown in FIG. 9, as in the case of FIG. 1, air is supplied to the armature 315 in the cup portion 321 through the recess 1122, and the temperature rise of the armature 315 can be suppressed.

  FIG. 10 is a longitudinal sectional view of a centrifugal fan 1b according to the fourth embodiment of the present invention. In the sirocco fan type centrifugal fan 1 shown in FIG. 1 and the housing main body shown in FIG. 7, concave portions 1122, 1122a, 1122b that partially enlarge the gap 14 are formed at positions facing the connecting plate 23. In the centrifugal fan 1b shown in FIG. 9, these recesses and gaps 14 are provided to face the opening 3211 (the edge) of the cup part 321 as in the case of the turbofan centrifugal fan shown in FIG. Other points are the same as in the first embodiment.

  As shown in FIG. 10, even when the concave portion 1122 of the annular convex portion 1121 is provided below the opening portion 3211 of the cup portion 321 instead of the lower side of the connecting plate 23, as in the first embodiment, Air can be efficiently supplied to the child 315 and the circuit board 316, and the temperature rise of the armature 315 and the circuit board 316 can be suppressed.

  9 and FIG. 10, even when the recess 1122 is provided between the opening 3211 of the cup portion 321 and the base portion 112, the range of the recess 1122 as shown in FIG. 5 and FIG. A plurality of recesses may be provided as shown in FIG.

  Even when the connecting plate 23 is provided on the side surface of the cup portion 321 as in the rotor portion 2 shown in FIGS. 11 and 12, the recess 1122 is provided between the opening portion 3211 and the base portion 112 as shown in FIG. The structure provided by can be used.

  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, in the centrifugal fan 1 shown in FIG. 1, an annular convex portion 1121 that reduces a gap between the connecting plate 23 and the base portion 112 is formed on the base portion 112, and a concave portion 1122 is provided on a part of the annular convex portion 1121. However, as shown in FIG. 13, a recess 1122 c may be formed in the flat base portion 112, and cooling air may be supplied from the recess 1122 c into the cup portion 321. A recess 1122c having a depth equal to or less than the thickness of the base portion 112 may be provided at the position of the recess 1122c, and the back surface of the base portion 112 may be flat, and the base portion 112 may protrude downward at the recess 1122c. May be.

  In addition, the range in which the concave portion provided in the base portion 112 expands the gap 14 is not limited to the above-described angle and number. For example, three or more concave portions may be provided in the annular convex portion 1121.

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

It is sectional drawing which shows the structure of the centrifugal fan which concerns on 1st Embodiment. It is a disassembled perspective view of a centrifugal fan. It is a top view which shows a housing main body and a stator part. It is a figure which shows the other example of a rotor part. It is a top view which shows the other preferable example of a housing main body. It is a top view which shows the other preferable example of a housing main body. It is a top view which shows the housing main body of the centrifugal fan which concerns on 2nd Embodiment. It is a perspective view which shows the housing main body of the centrifugal fan which concerns on 2nd Embodiment. It is sectional drawing which shows the structure of the centrifugal fan which concerns on 3rd Embodiment. It is sectional drawing which shows the structure of the centrifugal fan which concerns on 3rd Embodiment. It is a figure which shows the other example of a rotor part. It is a figure which shows the other example of a rotor part. It is a perspective view which shows the other preferable example of a housing main body.

Explanation of symbols

1, 1a, 1b Centrifugal fan 2 Impeller part 10 Housing 13 Exhaust port 14 Gap 22, 22a Blade 23 Connecting plate 112 Base part 113 Side wall part 312, 313 Ball bearing 315 Armature 316 Circuit board 321 Cup part 321a Yoke part 322 Field Magnet 1121 annular projection 1122, 1122a to 1122c recess 1131 delivery wall 1132 curved wall 1133 boundary 3211 opening J1 central axis

Claims (13)

A centrifugal fan,
A substantially bottomed cylindrical cup portion including a cylindrical yoke portion centered on a predetermined central axis;
A field magnet fixed to the inner surface of the cup part;
A plurality of wings connected to the cup portion and arranged in an annular shape around the central axis on the outside of the cup portion, and by rotating together with the cup portion, air is discharged from the bottom side of the cup portion. An impeller portion for taking in and discharging the air in a direction away from the central axis;
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;
A circuit board mounted between the armature and the base part;
With
The base portion protrudes toward the connecting plate and forms the gap while the concave portion partially enlarges the gap between the connecting plate that connects the plurality of blades on the base portion side and the base portion. And an annular convex portion
With respect to a direction parallel to the central axis, the upper surface of the concave portion is located below the upper surface of the circuit board, and the upper surface of the annular convex portion is located above the upper surface of the circuit board. Centrifugal fan. The centrifugal fan according to claim 1,
The side wall includes a delivery wall on the exhaust port side, and a curved wall on the upstream side of the delivery wall,
The concave portion expands a gap between the connecting plate and the base portion between the curved wall and the central axis in a range of 30 ° to 180 ° centering on the central axis. Centrifugal fan to play. The centrifugal fan according to claim 2,
The centrifugal fan according to claim 1, wherein the base portion further includes another concave portion that enlarges the gap between the connecting plate and the base portion on the exhaust port side of the concave portion. The centrifugal fan according to any one of claims 1 to 3,
The centrifugal fan is characterized in that the connecting plate continues to the opening of the cup portion and closes between the plurality of blades and the cup portion. The centrifugal fan according to any one of claims 1 to 4,
The centrifugal fan, wherein the base portion includes an annular convex portion that protrudes toward the connecting plate and forms the gap, and the concave portion is provided in the annular convex portion. A centrifugal fan,
A substantially bottomed cylindrical cup portion including a cylindrical yoke portion centered on a predetermined central axis;
A field magnet fixed to the inner surface of the cup part;
A plurality of wings connected to the cup portion and arranged in an annular shape around the central axis on the outside of the cup portion, and by rotating together with the cup portion, air is discharged from the bottom side of the cup portion. An impeller portion for taking in and discharging the air in a direction away from the central axis;
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;
A circuit board mounted between the armature and the base part;
With
The base portion protrudes toward the connecting plate and forms the gap while the concave portion partially enlarges the gap between the connecting plate that connects the plurality of blades on the base portion side and the base portion. And an annular convex portion
With respect to a direction parallel to the central axis, the upper surface of the concave portion is located below the upper surface of the circuit board, and the upper surface of the annular convex portion is located above the upper surface of the circuit board. Centrifugal fan. A centrifugal fan,
A substantially bottomed cylindrical cup portion including a cylindrical yoke portion centered on a predetermined central axis;
A field magnet fixed to the inner surface of the cup part;
An impeller portion having a plurality of wings extending radially from the outer surface of the cup portion, and taking in air from the bottom side of the cup portion by rotating with the cup portion and discharging the air in a direction away from the central axis When,
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;
A circuit board mounted between the armature and the base part;
With
The base portion protrudes toward the connecting plate and forms the gap while the concave portion partially enlarges the gap between the connecting plate that connects the plurality of blades on the base portion side and the base portion. And an annular convex portion
With respect to a direction parallel to the central axis, the upper surface of the concave portion is located below the upper surface of the circuit board, and the upper surface of the annular convex portion is located above the upper surface of the circuit board. Centrifugal fan. The centrifugal fan according to claim 6 or 7,
The side wall includes a delivery wall on the exhaust port side, and a curved wall on the upstream side of the delivery wall,
The concave portion enlarges a gap between the opening and the base portion between the curved wall and the central axis in a range of 30 ° to 180 ° centering on the central axis. Centrifugal fan to play. The centrifugal fan according to claim 8,
The centrifugal fan according to claim 1, wherein the base portion further includes another concave portion that enlarges the gap between the opening portion and the base portion on the exhaust port side of the concave portion. The centrifugal fan according to any one of claims 6 to 9,
The centrifugal fan, wherein the base portion includes an annular convex portion that protrudes toward the opening and forms the gap, and the concave portion is provided in the annular convex portion. The centrifugal fan according to claim 2 or 8,
The centrifugal fan, wherein the concave portion is provided toward the upstream side from a position facing a boundary between the delivery wall and the curved wall. The centrifugal fan according to claim 3 or 9,
The recess is provided on the upstream side of a position facing the boundary between the delivery wall and the curved wall, and the other recess includes a position facing the boundary, or on the downstream side of the position. A centrifugal fan characterized by being provided. The centrifugal fan according to any one of claims 1 to 12 ,
With respect to a direction perpendicular to the front Symbol central axis, a centrifugal fan wherein the recess is equal to or facing the gap between the circuit board and the armature.

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