JP2019086005A - Motor mounted on motor base part and blower fan - Google Patents

Abstract

To provide a blower fan capable of minimizing influence of vibrations transmitted to casing via a motor base even when the maximum rotational speed of the blower fan is increased to nearly 20000 rpm by optimizing a shape and an arrangement structure of a reinforcement rib formed on a motor base part.SOLUTION: A motor includes a casing 11, a motor base part 18 formed in a disc shape by providing a plurality of reinforcement ribs 21 extending radially outward from the outer circumferential side of a hollow cylindrical boss part 18a, and a plurality of spokes 20 which connect the motor base part 18 and the casing 11, the spokes and the motor base part being formed integrally with the casing 11. Therein, the number of the plurality of reinforcement ribs 21 is set to be equal to or larger than the number of the spokes 20, and a natural frequency of the casing 11 is set higher than the frequency transmitted to the casing 11 from the motor 15 when the motor 15 is rotated at 20000 rpm.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a blower fan, and more particularly to a blower fan used for cooling the inside of an apparatus such as an electronic device.

  In general, a blower fan has a casing having a hollow portion (opening) in the center, a rotating shaft, an impeller having a plurality of blades and integrally rotating with the rotating shaft, a motor for rotating the rotating shaft, and a motor A motor base portion is provided, and the impeller, the motor and the motor base portion are accommodated in the hollow portion of the casing.

  The motor base portion is integrally formed with a boss portion to which a hollow cylindrical bearing housing provided with a bearing for supporting a rotating shaft is fitted and attached at the center thereof. The stator of the motor is attached to the outside of the bearing housing attached to the boss, and the rotating shaft is rotatably attached to the inside through the bearing. Further, the motor base portion is connected to the casing by a plurality of spokes.

  Then, when the motor is driven, the rotation shaft rotates with the impeller, and the rotation of the impeller causes fluid (air) to be sucked into the impeller from one end side of the hollow portion of the casing, that is, the suction port and pass through the inside of the casing. From the other end side of the hollow portion of the casing, that is, from the discharge port, it is blown out to the outside of the casing. At this time, when it is necessary to increase the pressure of the fluid blown out of the casing, a fixed wing may be provided in the vicinity of the discharge port of the casing, and the spoke may also serve as the fixed wing. The casing, the motor base and the spokes are integrally formed of resin, metal or the like.

  By the way, such a blower fan is attached to an electronic device, and is used for efficiently discharging heat generated from the electronic component inside the electronic device to the outside of the electronic device to cool the electronic component. Therefore, the high air volume of the blower fan (the amount of air delivered by the fan per unit time) is required. Also, in electronic devices such as servers, the high-density mounting inside the housing makes the space through which the air flows smaller and smaller, and for the blower fan that cools the inside of the housing, the high static pressure Power is also required.

  In order to obtain the high air volume and high static pressure of the blower fan, it is necessary to rotate the motor for rotating the impeller at high speed. However, when the motor is rotated at high speed, the vibration accompanying the high speed rotation of the motor is transmitted to the casing through the bearing, and the vibration is also transmitted to the electronic device equipped with the blower fan, and the electronic device also vibrates. There's a problem. In particular, when the vibration accompanying the rotation of the motor resonates with the natural frequency of the casing, the vibration becomes large, and as a result, abnormal vibration may occur in the electronic device to cause a serious problem.

  To solve such problems, a blower fan has been proposed in which a plurality of reinforcing reinforcing ribs are formed on the motor base portion to strengthen the structure of the housing and to suppress the occurrence of vibration (for example, Patent Document 1) reference).

JP, 2006-57631, A

  However, although the technology described in Patent Document 1 is a blower fan in which the structure of the housing is reinforced by forming a plurality of reinforcing reinforcing ribs in the motor base portion, the shape of the reinforcing reinforcing rib formed in the motor base portion It does not fully disclose the structure.

  Therefore, the present invention has been made in view of the above problems, and provides a rotor and a blower fan mounted on a motor base portion that can reduce the influence of vibrations transmitted to a casing through the motor base. The purpose is that.

The configuration of the present invention is as follows.
(1) A rotating shaft, an impeller, a motor for rotating the rotating shaft and the impeller, a casing having a suction port, a motor base portion disposed inside the casing, the casing, and the motor base portion And a bearing for supporting the rotating shaft, the motor includes a cup-shaped magnetic yoke, and a rotor magnet attached to the inner surface of the magnetic yoke. The motor base portion includes a cylindrical boss portion, an outer peripheral side surface, and a plurality of reinforcing ribs connecting the boss portion and the outer peripheral side surface, and the boss portion is a portion of the motor base portion. The boss portion projects from the surface on the suction port side, and the boss portion supports the motor and the rotary shaft via the bearing, and the plurality of reinforcing ribs in the radial direction The end portion of the rotary shaft on the motor base side in the radial direction facing the bearing is opposed to the surface on the suction port side of the plurality of reinforcing ribs or the motor base, The reinforcing rib is formed so that the width gradually decreases from the outer peripheral side of the boss portion to the outer peripheral side of the motor base portion.
(2) In the above (1), the plurality of reinforcing ribs are provided on the surface on the suction port side of the disk-like motor base portion.
(3) In the above (1) or (2), the spokes are joined to the outer peripheral surface of the motor base portion, and the plurality of reinforcing ribs are joined to the outer peripheral side surface of the motor base portion.
(4) In any one of the above (1) to (3), the number of the plurality of reinforcing ribs is the same as or larger than the number of the spokes.
(5) In any of the above (1) to (4), an end of the rotary shaft on the motor base side in the rotary shaft direction is such that the boss and a part of the reinforcing rib are connected. It is also arranged outside with respect to the position.
(6) A motor base portion, a rotary shaft, a rotor, a stator, and a bearing for supporting the rotary shaft provided on the motor base portion, the rotor being attached to the magnetic yoke and the inner surface of the magnetic yoke The motor base portion includes a cylindrical boss portion and a plurality of reinforcing ribs, and the boss portion projects from the surface of the motor base portion on the rotor side. The boss portion supports the rotor and the rotary shaft via the bearing, and the plurality of reinforcing ribs face the bearing in the radial direction, and the motor base portion in the radial direction The end of the rotary shaft on the side faces the surface of the rotor side of the plurality of reinforcing ribs or the motor base portion, and the plurality of reinforcing ribs are the motor from the outer peripheral side of the boss portion Over the width to the outer side of the scan part is formed so as to gradually decrease, the motor mounted on the motor base.
(7) In the above (6), the plurality of reinforcing ribs are provided on the rotor-side surface of the disk-like motor base portion.
(8) In the above (6) or (7), the end of the rotary shaft on the motor base side in the rotary shaft direction is at a position where the boss and a part of the reinforcing rib are connected. In contrast, it is also located outside.
(9) The motor mounted on the motor base in any one of (6) to (8), an impeller, a casing having a suction port, and a spoke for connecting the casing and the motor base The blower fan, wherein the motor base is disposed inside the casing.

  ADVANTAGE OF THE INVENTION According to this invention, the ventilation fan which does not produce an abnormal vibration can be provided.

It is sectional drawing of the ventilation fan shown as one Embodiment of this invention. It is a perspective view which shows the casing of the ventilation fan shown in FIG. The casing of FIG. 2 is shown, (a) is the top view, (b) is the AA expanded sectional view of (a). It is the graph which showed the number of the reinforcing ribs formed in the motor base part, and the value of the natural frequency of a housing.

  Hereinafter, modes for carrying out the present invention (hereinafter, referred to as “embodiments”) will be described in detail based on the attached drawings. In the following description, the expression indicating the upper and lower directions is not absolute, and is appropriate when each part of the blower fan of the present invention is drawn, but when the posture changes. Should be interpreted in response to changes in posture.

  As shown in FIG. 1, the blower fan 10 in an example of the embodiment of the present invention is an axial flow fan, and has a casing 11, a rotating shaft 12, and a plurality of blades 13 on the outer periphery. Supports the bearing housing 17 and the hollow cylindrical bearing housing 17 on which the impeller 14 rotating integrally, the motor 15 for rotating the rotating shaft 12, and a pair of upper and lower bearings 16a and 16b supporting the rotating shaft 12 are mounted The rotary shaft 12, the impeller 14, the motor 15, the bearing housing 17 and the motor base 18 are disposed in the casing 11.

  More specifically, as shown in FIGS. 1 to 3, the casing 11 is formed as a rectangular frame in plan view by providing a circular venting cavity 19 penetrating in the front and back in the center. ing. In the casing 11, the motor base portion 18 is disposed at the center of the hollow portion 19, and a plurality of spokes 20 (7 in the embodiment) between the inner peripheral surface of the hollow portion 19 and the outer peripheral surface of the motor base portion 18 And the motor base portion 18 and the spokes 20 are integrally molded with resin. And as shown in FIG. 1, the suction port 19a and the discharge port 19b are formed in the upper and lower ends of the hollow part 19, respectively.

  The plurality of spokes 20 are disposed on the side of the discharge port 19b of the casing 11 as shown in FIG. 1 and, as shown in FIG. 3A, the motor base portion 18 at an equal angle in the circumferential direction. Are radially formed toward the inner peripheral surface of the hollow portion 19 from the outer peripheral surface of the lower housing 21. The plurality of spokes 20 respectively increase the pressure of the air blown out of the casing 11 and rectify the discharged air so as to be inclined at a predetermined angle with respect to the plane orthogonal to the rotating shaft 12. , Also functions as a fixed wing.

  The motor base portion 18 supported on the casing 11 by the spokes 20 is provided on the discharge port 19 b side of the casing 11 together with the spokes 20. Further, as shown in FIGS. 2 and 3, a hollow cylindrical boss 18a projecting toward the suction port 19a is integrally provided at the center and formed in a disk shape in plan view. In the boss portion 18a, one end side of the bearing housing 17 is fitted and inserted concentrically and fixedly attached. An adhesive is used to fix the bearing housing 17.

  Furthermore, the surface from which the boss 18a of the motor base 18 is projected, ie, the surface facing the suction port 19a, corresponds to the spoke 20 from the outer peripheral surface of the boss 18a to the outer periphery of the motor base 18 A plurality of reinforcing ribs 21 (seven in the embodiment) extending in the direction and radially toward the joint point C between the motor base 18 and the spokes 20 are provided. The respective reinforcing ribs 21 project outward from the back surface of the motor base portion 18 in a mountain shape in cross section, as shown in FIG. 3 (b) as a cross section along line A-A in FIG. 3 (a). It is integrally formed. The cross-sectional shape of the reinforcing rib 21 is not limited to the shape shown in FIG. 3B, and may be formed into another triangle, square, trapezoid or the like.

  As shown in FIGS. 3 (a) and 3 (b), the respective reinforcing ribs 21 have equal angles in the circumferential direction, and all have the same shape, and the distance from the outer peripheral surface of the boss 18a to the joint point C is The same width (circumferential direction) W and the same height (axial direction) H are formed. And by providing the some reinforcement rib 21 in this way, the intensity | strength of the junction location C is heightened, and reinforcement of the whole casing 11 is simultaneously aimed at. As described in more detail later, when the rotation of the motor 15 is rotated at 20000 rpm, the natural frequency of the casing 11 is set to be higher than the frequency at which the rotation of the motor 15 is transmitted to the casing 11.

  Although the casing 11, the motor base portion 18, the spokes 20 and the reinforcing rib 21 are integrally formed of resin, they may be integrally formed of metal or the like. Alternatively, the bearing housing 17 may be resin-molded integrally with the boss 18 a of the motor base 18.

  As shown in FIG. 1, the rotary shaft 12 is rotatably supported through a pair of bearings 16 a and 16 b mounted on the inner periphery of the bearing housing 17, and is rotatably supported at the upper end thereof. Are attached together.

  Although the bearing housing 17 is a separate part in this embodiment, it may be integral with the boss 18a.

  The impeller 14 has a hub 22 that rotates integrally with the rotating shaft 12, and the plurality of blades 13 are provided on the outer peripheral surface of the hub 22.

  The hub 22 is formed by injection molding a general resin material (PBT, synthetic resin such as ABS), and at the time of molding, one end (upper end) side is closed in a molding die (not shown), and the other An end (lower end) side is opened, and a magnetic yoke 24 formed in a substantially cup shape with a circular cross section and having the rotor magnet 23 of the motor 15 attached to the inner peripheral surface, and the rotating shaft 12 are disposed. By injecting a resin material into the mold, as shown in FIG. 1, a disk-like ceiling 22a connected and supported by the rotary shaft 12 and a cylindrical portion 22b extending in the axial direction are provided. It is formed in a substantially cup shape with a circular cross section, with the upper end side closed and the lower end side opened. At the same time, the plurality of blades 13 are integrally formed on the outer peripheral surface of the cylindrical portion 22 b of the hub 22.

  As shown in FIG. 1, the motor 15 comprises a rotor 15a comprising a magnetic yoke 24 on the impeller 14 side and a rotor magnet 23 mounted on the inner peripheral surface of the magnetic yoke 24; The impeller 14 and the rotary shaft 12 are integrally rotated by rotating the rotor 15a with respect to the stator 15b.

  The stator 15b is attached to the outer peripheral surface of the bearing housing 17 from the suction port 19a side, as shown in FIG. The stator 15 b includes an iron core 25 fitted and attached to the outer periphery of the bearing housing 17 and a drive coil 27 wound around the iron core 25 via an insulator 26. Further, a motor drive circuit board 28 mounted with an electronic component for controlling a drive current supplied to the coil 27 is fixedly attached to the insulator 26 at a lower portion of the stator 15b. It is electrically connected to an external power supply (not shown) through a lead (not shown).

  In the blower fan 10 configured as described above, when a drive current is supplied from the circuit board 28 to the coil 27 of the motor 15, the rotor 15a is moved and the rotation shaft 12 and the impeller 14 rotate integrally. Further, when the impeller 14 rotates, air which is a fluid is drawn into the blades 13 of the impeller 14 from the suction port 19 a of the casing 11, passes through the inside of the casing 11, and the outside of the casing 11 from the discharge port 19 b of the casing 11. Be blown out. At this time, the plurality of spokes 20 provided on the discharge port 19b side of the casing 11 rectify the air blown out of the casing 11 and increase the pressure of the air. As a result, in an electronic device such as a server to which the blower fan 10 is attached, ventilation (or air circulation) is performed to perform internal cooling.

  By the way, in electronic devices such as servers, the high-density mounting inside the housing makes the space through which the air flows smaller and smaller, and a high air volume and high static pressure are required for the blower fan 10 for cooling the inside of the housing. Therefore, in order to obtain a high air volume and a high static pressure of the blower fan 10, the maximum number of rotations of the motor 15 that rotates the impeller 14 may be rotated up to 20000 rpm. When the motor 15 is rotated at high speed, the accompanying vibration is transmitted to the casing 11 through the bearings 16a and 16b, and the vibration is also transmitted to the electronic device equipped with the blower fan 10, and as a result, the vibration is also transmitted to the electronic device Will occur. In this case, when the vibration accompanying the rotation of the motor 15 resonates with the natural frequency of the casing 11, the vibration becomes even larger, and as a result, there is a possibility that abnormal vibration may occur in the electronic device.

  Table 1 is a value estimated by analysis of the natural frequency (Hz) of the casing 11 in that case with the number of reinforcing ribs 21 formed on the motor base portion 18 of the casing 11 and the number of spokes 20 as parameters, and The resonant rotation speed of the motor 15 based on FIG. The details of the estimation method by analysis will be omitted.

  In Table 1, Comparative Example 1 is a casing 11 in which four spokes 20 and four reinforcing ribs 21 are formed. Comparative Example 2 is a casing 11 in which six spokes 20 and six reinforcing ribs 21 are formed. Example 1 uses the casing 11 shown in FIGS. 1 to 3 which is an embodiment of the present invention, and has seven spokes 20 and seven reinforcing ribs 21. The reinforcing rib 21 is formed in the same shape of the casing 11 as the comparative example 1, the comparative example 2 and the example 1 so that the reinforcing rib 21 is joined to the portion C where the spoke 20 is joined to the motor base portion 18.

  As shown in Table 1, the natural frequency of the casing estimated in the analysis is about 252 Hz in Comparative Example 1, about 275 Hz in Comparative Example 2, and about 365 Hz in Example 1. From this, it can be seen that when the number of the spokes 20 and the number of the reinforcing ribs 21 are the same, the natural frequency of the casing 11 is increased as the number of the spokes 20 and the number of the reinforcing ribs 21 are increased. Here, in the first embodiment, X (referred to as an oscillating frequency) when the maximum number of rotations of the motor 15 for rotating the impeller 14 of the blower fan 10 is 20000 rpm is a ratio of rotations (365: X = 21910: 20000) ), That is, X = 334, that is, the vibration frequency of the rotation of the motor 15 is about 334 Hz.

  For this reason, when the natural frequency of the casing 11 obtained by analysis in advance is lower than the vibration frequency 334 Hz, the frequency of the casing 11 and the natural frequency of the casing 11 can be resonated due to the rotation of the motor 15 There is sex. As a result, an abnormal vibration may occur in the electronic device or the like.

  From this, as shown in Table 1, in the casings 11 of Comparative Example 1 and Comparative Example 2, the natural frequencies of the casing 11 are 252 Hz and 275 Hz, respectively, which are lower than 334 Hz. Therefore, when the maximum number of revolutions of the motor 15 for rotating the impeller 14 of the blower fan 10 is set to 20000 rpm, the frequency of the casing 11 generated along with this may possibly resonate with the natural frequency of the casing 11 .

  On the other hand, Example 1 shown in FIGS. 1-3 has shown the value (365 Hz) whose intrinsic frequency of the casing 11 is higher than 334 Hz. As a result, even if the maximum rotational speed of the motor 15 for rotating the impeller 14 of the blower fan 10 is 20000 rpm, the resonance point is not reached, and abnormal vibration occurring in the electronic device or the like on which the blower fan 10 is mounted can be prevented. .

  Table 2 sets the number of spokes 20 to seven in the casing 11 in the blower fan 10 (Example 1) which is the embodiment shown in FIGS. 1 to 3 and forms the reinforcing rib 21 formed on the motor base portion 18 In the case where the natural frequency of the casing 11 is estimated by analysis, and the number of resonance rotations of the motor 15 based on the estimated value, respectively. FIG. 4 is a graph showing estimated values of the natural frequency of the casing 11 when the number of reinforcing ribs 21 shown in Table 2 is changed.

  In Table 2, the casing A is a casing in which the number of the spokes 20 is seven and the reinforcing rib 21 is not formed. The casing B is a casing in which the number of the spokes 20 is seven and the number of the reinforcing ribs 21 is four. The casing C is a casing in which the number of the spokes 20 is seven and the number of the reinforcing ribs 21 is five. The casing D is a casing in which the number of the spokes 20 is seven and the number of the reinforcing ribs 21 is six. The casing E is a casing in which the number of the spokes 20 is seven and the number of the reinforcing ribs 21 is seven, and the casing according to the embodiment of the present invention shown in FIGS. 1 to 3 (Example 1) It is. The casing F is a casing in which the number of the spokes 20 is seven and the number of the reinforcing ribs 21 is nine. All the casings have the same shape, and the reinforcing rib 21 is formed so as to be joined to the portion C where the spokes 20 join with the motor base portion 18 only in the casing E of the embodiment 1 which is the embodiment of the present invention.

  As shown in Table 2 and FIG. 4, when seven spokes 20 of the casing 11 are formed, the impeller 14 of the blower fan 10 is formed by forming six or more reinforcing ribs 21 formed on the motor base portion 18. Even when the maximum rotation speed of the motor 15 to be rotated is 20000 rpm, the natural frequency of the casing 11 can be made higher (337 Hz) than 334 Hz which is a value estimated by analysis.

  However, when the number of reinforcing ribs 21 formed in the motor base portion 18 is six, the value is a value slightly higher than the vibration frequency 334 Hz of the blower fan 10, and it can not be said that there is sufficient margin. Therefore, by forming seven or more reinforcing ribs 21 formed on the motor base portion 18 as the number of the spokes 20, the natural frequency of the casing 11 is more than the vibration frequency 334 Hz of the blower fan 10 High value (365 Hz) can be obtained. As a result, when the number of reinforcing ribs 21 formed on the motor base portion 18 is at least 6 or more, more preferably 7 or more, the maximum rotational speed of the motor 15 for rotating the impeller 14 of the blower fan 10 is 20000 rpm. Even in this case, the influence of the vibration transmitted to the casing 11 through the motor base portion 18 can be reduced to prevent abnormal vibration generated in an electronic device or the like on which the blower fan 10 is mounted.

  When the number of reinforcing ribs 21 formed on the motor base portion 18 is the same as that of the spokes 20, it is desirable that the reinforcing ribs 21 be formed so that the spokes 20 join with the motor base portion 18.

  In the embodiment, although the case where the number of the spokes 20 is seven has been described, the number may be seven or more. When at least seven spokes 20 are formed, if seven or more reinforcing ribs 21 are formed in the motor base portion 18, when the maximum number of revolutions of the motor 15 for rotating the impeller 14 is 20,000 rpm, Since the frequency is higher than the vibration frequency of the rotation of the motor 15, abnormal vibration can be prevented.

  Further, the plurality of reinforcing ribs 21 are extended from the outer peripheral side of the boss portion 18a to the outer peripheral side surface of the motor base portion 18 with the same width (circumferential direction) W and the same height (axial direction) H However, the width W may gradually decrease as it extends from the outer peripheral side of the boss portion 18a to the outer peripheral side of the motor base portion 18, and the height H may be gradually reduced. As described above, the width of the plurality of reinforcing ribs 21 is made wider at the boss portion 18a, and the width is gradually reduced as it extends to the outer peripheral side of the motor base portion 18, thereby efficiently reinforcing the boss portion 18a and excess reinforcement. Thus, the weight of the casing 11 can be reduced.

  Furthermore, the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like as long as the object of the present invention can be achieved are included in the present invention.

DESCRIPTION OF SYMBOLS 10 Blower fan 11 Casing 12 Rotor shaft 13 Blades 14 Impeller 15 Motor 15a Rotor 15b Stator 16a, 16b Bearing 17 Bearing housing 18 Motor base part 19 Cavity part 19a Suction port 19b Discharge port 20 Spoke 21 reinforcement rib

The present invention has been made in view of the above problems, it is possible to reduce the influence of vibration transmitted to the casing via a motor base, motors mounted on the motor base unit, a blower fan It is intended to be provided.

The configuration of the present invention is as follows.
The motor mounted on the motor base portion of the present invention comprises a rotor having a magnetic yoke and a rotor magnet, a stator, a rotary shaft, a bearing housing, and a bearing mounted on the inner periphery of the bearing housing for supporting the rotary shaft. And a motor base portion having a boss portion for supporting the bearing housing and a plurality of reinforcing ribs, wherein the bearing housing and the boss portion are integrated, and the inner surface of the bearing housing facing the bearing is of the rotating shaft. In the longitudinal direction, from one end of the bearing to the other end, along the outer peripheral surface of the bearing, the integral boss portion and the bearing housing project from the rotor side surface of the motor base portion. The reinforcing rib faces the bearing through the integral boss portion and bearing housing, and in the radial direction, the end portion of the rotary shaft on the motor base portion side is plural It is rotor-side surface facing the reinforcing rib or the motor base.
In the above, a plurality of reinforcing ribs may be provided on the rotor-side surface of the disk-shaped motor base portion.
In the above, the plurality of reinforcing ribs on the boss portion side may be wider than the plurality of reinforcing ribs on the outer peripheral side of the motor base portion.
In the above, in the rotation axis direction, the end of the rotation axis on the motor base side may be disposed outside the position where the boss and a part of the reinforcing rib are connected.
A blower fan according to the present invention comprises a motor mounted on the motor base in any of the above , an impeller, a casing having a suction port, and a spoke for connecting the casing and the motor base, Is disposed inside the casing .

Claims (9)

With the rotation axis,
With the impeller,
A motor for rotating the rotating shaft and the impeller;
A casing having a suction port;
A motor base disposed inside the casing;
Spokes connecting the casing and the motor base;
And a bearing for supporting the rotating shaft,
The motor includes a cup-shaped magnetic yoke, and a rotor magnet attached to an inner surface of the magnetic yoke.
The motor base includes a cylindrical boss, an outer peripheral side, and a plurality of reinforcing ribs connecting the boss and the outer peripheral side.
The boss portion projects from a surface on the suction port side of the motor base portion,
The boss portion supports the motor and the rotation shaft via the bearing,
In the radial direction, the plurality of reinforcing ribs face the bearing,
In the radial direction, the end of the rotary shaft on the motor base side is opposed to the surface on the suction port side of the plurality of reinforcing ribs or the motor base,
The plurality of reinforcing ribs are formed such that the width gradually decreases from the outer peripheral side of the boss portion to the outer peripheral side of the motor base portion.
Blower fan.   The blower fan according to claim 1, wherein the plurality of reinforcing ribs are provided on a surface of the disk-like motor base portion on the suction port side. The spokes are joined to the outer peripheral surface of the motor base portion,
The blower fan according to claim 1, wherein the plurality of reinforcing ribs are joined to an outer peripheral side surface of the motor base portion.   The blower fan according to any one of claims 1 to 3, wherein the number of the plurality of reinforcing ribs is equal to or larger than the number of the spokes.   The end portion of the rotary shaft on the motor base portion side in the rotary shaft direction is also disposed outside the position where the boss portion and a part of the reinforcing rib are connected. The blower fan according to any one of claims 1 to 4. Motor base and
A rotating shaft, a rotor, a stator, and a bearing for supporting the rotating shaft, provided on the motor base portion;
The rotor includes a magnetic yoke and a rotor magnet attached to an inner surface of the magnetic yoke.
The motor base includes a cylindrical boss and a plurality of reinforcing ribs.
The boss portion protrudes from a surface on the rotor side of the motor base portion,
The boss portion supports the rotor and the rotation shaft via the bearing,
In the radial direction, the plurality of reinforcing ribs face the bearing,
In the radial direction, the end of the rotating shaft on the motor base side is opposed to the surface of the rotor side of the plurality of reinforcing ribs or the motor base,
The motor mounted on a motor base portion, wherein the plurality of reinforcing ribs are formed so that the width gradually decreases from the outer peripheral side of the boss portion to the outer peripheral side of the motor base portion.   The motor mounted on a motor base according to claim 6, wherein the plurality of reinforcing ribs are provided on a surface of the disk-like motor base on the rotor side.   The end portion of the rotary shaft on the motor base portion side in the rotary shaft direction is also disposed outside the position where the boss portion and a part of the reinforcing rib are connected. A motor mounted on the motor base portion according to claim 6 or claim 7. A motor mounted on the motor base portion according to any one of claims 6 to 8.
With the impeller,
A casing having a suction port;
And a spoke connecting the casing and the motor base.
The blower fan, wherein the motor base portion is disposed inside the casing.

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