JP2011185113A - Cooling fan device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling fan device efficiently eliminating the heat of a motor stator. <P>SOLUTION: In this cooling fan device 10, when a multi-blade fan 11 is driven to rotate, air moving in a clearance between a motor control board 60 and a case bottom wall 13 abuts on a part, wherein the motor stator 40 and the case bottom wall 13 are fixed to each other, and flows to the motor stator 40 through a central through-hole 61. Since the central through hole 61 is opened up to a part, wherein a position detecting element 62 is not arranged, in an annular region of the motor control board 60 opposite to a rotor, the central through-hole 61 faces a part of the annular clearance between the inside surface of the motor rotor 50 and the outside surface of the motor stator 40, and air flows into the motor rotor 50 through the central through hole 61. With this structure, the heat of the motor stator 40 can be efficiently eliminated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cooling fan device that feeds air by rotationally driving a multiblade fan with a brushless motor.

  Conventionally, as this type of cooling fan device, a motor rotor of a brushless motor has a cylindrical shape and is disposed in a central cylindrical portion of a multiblade fan, and further, a motor stator is disposed on the inner side thereof ( For example, see Patent Document 1).

Japanese Patent Laid-Open No. 11-346458 (FIG. 1)

  However, the cooling fan device described above has a structure in which the periphery of the motor stator is doubly surrounded by the motor rotor and the cylindrical portion of the multiblade fan, so that heat tends to accumulate in the motor stator. For this reason, the brushless motor has been stopped due to abnormal heat generation, and in order to avoid the abnormal heat generation, the output rotational speed of the brushless motor has been lowered, resulting in insufficient airflow.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a cooling fan device capable of efficiently removing heat from a motor stator.

  The cooling fan device (10, 10V) according to the invention of claim 1 made to achieve the above object comprises rotating the multi-blade fan (11) with a brushless motor (30) and rotating the multi-blade fan (11). ) And a cooling fan device (10) for supplying air from a suction port (14) on one end surface of the fan case (12) containing the brushless motor (30) to a discharge port (15) on the side surface, 30), the motor rotor (50) of the brushless motor (30) is disposed in the cylindrical portion (16) in the center of the multiblade fan (11), and the motor stator (40) of the brushless motor (30) is placed on the motor rotor (50). One end of the motor stator (40) is fixed to the case bottom wall (13) on the opposite side of the suction port (14) of the fan case (12), and the brushless motor (30). The motor control board (60) is provided with a central through hole (61, 71, 72, 73, 74) that is loosely fitted to the outside of the fixed portion between the motor stator (40) and the case bottom wall (13) to control the motor. The substrate (60) is disposed with a gap between the case bottom wall (13) and the multiblade fan (11), and the rotor facing the end surface of the motor rotor (50) in the motor control substrate (60). A position detecting element (62) for detecting the rotational position of the motor rotor (50) is mounted in the opposed annular region, and the portion of the rotor opposed annular region where the position detecting element (62) is not disposed It is characterized in that the central through hole (61, 71, 72, 73, 74) is open.

  According to a second aspect of the present invention, in the cooling fan device (10, 10V) according to the first aspect, the conical shape protrudes from the case bottom wall (13), and one end surface of the motor stator (40) is fixed to the tip. A conical pedestal portion (23) is provided, and the air between the motor control board (60) and the case bottom wall (13) is passed through the central through hole (23A) by the inclined side surface (23A) of the conical pedestal portion (23). 61, 71, 72, 73, 74) can be guided into the motor rotor (50).

  According to a third aspect of the present invention, in the cooling fan device (10V) according to the first or second aspect, the motor control board projects from either the motor control board (60) or the case bottom wall (13) toward the other, (60) and the case bottom wall (13) are characterized in that a guide protrusion (70) is provided for guiding the air flowing between the central through hole (61) and the air flowing between the case bottom wall (13).

  According to a fourth aspect of the present invention, in the cooling fan device (10, 10V) according to any one of the first to third aspects, the central through hole (61, 71) has a shape that is elongated in one direction. It has the characteristics in that place.

  According to a fifth aspect of the present invention, in the cooling fan device (10, 10V) according to the fourth aspect, one end in the longitudinal direction of the central through hole (61, 71) is connected to the motor stator (40) and the discharge port ( 15), the fan case (12) is characterized by being arranged between the fan case (12) and the open end (15K).

  According to a sixth aspect of the present invention, in the cooling fan device (10, 10V) according to the fifth aspect, the FET (63) of the inverter circuit for generating the motor driving current is connected to the outlet of the motor control board (60). It is characterized by being arranged between (15) and the motor stator (40).

[Invention of Claim 1]
In the cooling fan device (10, 10V) of claim 1, when the multiblade fan (11) is rotationally driven by the brushless motor (30), the inside of the fan case (12) is changed from the suction port (14) to the discharge port (15). And air flows. Then, the air in the gap between the case bottom wall (13) of the fan case (12) and the multiblade fan (11) also flows toward the discharge port (15), and the motor control board (60) disposed in the gap. ) Heat is removed. Then, the air flowing through the gap between the motor control board (60) and the case bottom wall (13) is transferred from the central through hole (61, 71, 72, 73, 74) of the motor control board (60) to the motor stator ( Head to 40). Here, in the present invention, the central through hole (61) opens to the rotor-facing annular region facing the end surface of the motor rotor (50) in the motor control board (60). Air that has passed through the central through holes (61, 71, 72, 73, 74) easily flows into the annular gap between the inner surface and the outer surface of the motor stator (40). As a result, air around the motor stator (40) flows and heat of the motor stator (40) can be efficiently removed, and abnormal heat generation of the brushless motor (30) can be prevented. By increasing the output rotational speed of the brushless motor (30), it becomes possible to increase the amount of blown air.

[Invention of claim 2]
In the cooling fan device (10, 10V) according to claim 2, the motor control board (60) and the case bottom wall are guided by the inclined side surface (23A) of the conical pedestal portion (23) raised from the case bottom wall (13). Air between (13) flows smoothly from the central through hole (61, 71, 72, 73, 74) toward the motor stator (40), and the heat of the motor stator (40) can be efficiently removed. It becomes possible.

[Invention of claim 3]
According to the cooling fan device (10V) of the third aspect, the air flowing between the motor control board (60) and the case bottom wall (13) is collected by the guide protrusion (70) from the central through hole (61). It can be directed to the motor stator (40), and the efficiency of heat removal of the motor stator (40) is further improved.

[Invention of claim 4]
In the cooling fan device (10, 10V) according to claim 4, since the central through hole (61, 71) has a shape elongated in one direction, both sides of the central through hole (61, 71) in the short direction. Alternatively, by arranging the position detection element (62) on one side, the distance from the position detection element (62) to the opening edge of the central through hole (61, 71) in the motor control board (60) is widened, and the motor The strength of the vicinity of the position detection element (62) on the control board (60) can be sufficiently secured.

[Invention of claim 5]
In the cooling fan device (10, 10V) according to claim 5, one end in the longitudinal direction of the central through hole (61, 71) is an inner surface of the fan case (12) among the motor stator (40) and the discharge port (15). Therefore, air can be efficiently directed to the motor stator (40) through the central through holes (61, 71).

[Invention of claim 6]
According to the cooling fan device (10, 10V) of claim 6, since the FET (63) is disposed between the discharge port (15) and the motor stator (40) of the motor control board (60), the FET ( The heat of 63) can be prevented from moving toward the motor stator (40), and the FET (63) can be efficiently cooled by the air collected at the discharge port (15).

The perspective view of the cooling fan apparatus which concerns on 1st Embodiment of this invention. Top view of cooling fan device FIG. 2 is a side sectional view of the cooling fan device taken along the line AA in FIG. 2. FIG. 3 is a bottom sectional view of the cooling fan device taken along the line BB in FIG. 3. Bottom sectional view of a part of the cooling fan unit 4 is a side sectional view of the cooling fan device taken along the line CC of FIG. 4 is a side sectional view of the cooling fan device taken along the line DD in FIG. Bottom sectional view of a cooling fan device according to a second embodiment The bottom sectional view which expanded some cooling fan devices concerning the modification of the present invention. The bottom sectional view which expanded some cooling fan devices concerning the modification of the present invention.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the cooling fan device 10 of this embodiment includes a multiblade fan 11 in a fan case 12. The fan case 12 has a structure in which the discharge duct 12B protrudes from the side surface of the flat, substantially cylindrical fan housing portion 12A. The discharge duct 12B includes a first duct side wall 12C extending in a tangential direction from the side surface of the fan housing portion 12A, and a second duct side wall 12D disposed parallel to the first duct side wall 12C and closer to the center of the fan housing portion 12A. It has a rectangular tube shape. The inside of the discharge duct 12B is a discharge port 15.

  A suction port 14 is formed in the ceiling wall 12T at one end of the fan housing portion 12A. As shown in FIG. 2, the suction port 14 is circular. The gap between the opening edge of the suction port 14 and the inner side surface of the fan accommodating portion 12A is the narrowest at a position close to the second duct side wall 12D, and gradually increases from there toward the clockwise direction in FIG. Has been. As shown in FIG. 3, an opening protrusion 14T is formed on the inner surface of the ceiling wall 12T by curving the opening edge of the suction port 14 toward the inside of the fan accommodating portion 12A.

  The entire one end surface of the fan case 12 in the flat direction is constituted by the case bottom wall 13, and the entire remaining part is constituted by the case main body 12 </ b> H. The case bottom wall 13 is screwed to a plurality of fixed protrusions 12V protruding laterally from the position near the case bottom wall 13 on the outer side surface of the case main body 12H. The suction port 14 is formed on the case body 12H side. Further, as shown in FIG. 1, a plurality of case fixing protrusions 12 </ b> W project laterally from the position near the ceiling wall 12 </ b> T on the outer surface of the case main body 12 </ b> H.

  The multi-blade fan 11 is generally called a “sirocco fan” and includes a plurality of blade plates 17 around a central cylindrical portion 16. The multiblade fan 11 is disposed in the fan case 12 so that the center thereof overlaps the center of the suction port 14.

  As shown in FIG. 3, the cylindrical portion 16 of the multiblade fan 11 is formed by closing one end of a cylindrical wall 16A with a top plate 16B, and gradually increases in diameter as the cylindrical wall 16A moves away from the top plate 16B. It is the rotary collar part 16C which protruded to the side in parallel with the top plate 16B. Further, the top plate 16B is disposed at the center in the flat direction of the fan accommodating portion 12A, and the rotating collar portion 16C is disposed near the case bottom wall 13. The top plate 16B may be arranged on either the upper side or the lower side of the center in the flat direction of the fan accommodating portion 12A.

  The blade plate 17 group stands up from the outer edge portion of the rotating collar portion 16 </ b> C and extends higher than the cylindrical portion 16. Further, as shown in FIG. 2, when the multiblade fan 11 is viewed from the axial direction, each blade plate 17 is inclined with respect to the radial direction of the multiblade fan 11. Is rotated in a predetermined direction (the direction of the arrow in FIG. 2), the air inside the blade plate 17 group is fed to the side of the blade plate 17 group. Further, as shown in FIG. 3, the outer edge portion on the side away from the rotation center of the multiblade fan 11 in the blade plate 17 group is covered by the ceiling wall 12T of the fan case 12, and as shown in FIG. It protrudes outward from the rotating collar 16C. As shown in FIG. 3, a wing tip projection 17T protrudes from an end on the ceiling wall 12T side of the outer edge of the wing plate 17 group, and the wing tip projection 17T and the inner surface of the ceiling wall 12T The opening protrusion 14T is opposed to the suction port 14 in the radial direction.

  A brushless motor 30 is housed inside the fan case 12 together with the multiblade fan 11. The motor rotor 50 of the brushless motor 30 has a cylindrical shape and is disposed in the cylindrical portion 16 of the multiblade fan 11, and the motor stator 40 is disposed inside the motor rotor 50. Further, one end of the motor stator 40 is fixed to the case bottom wall 13, and the motor rotor 50 and the multiblade fan 11 are fixed to the motor drive shaft 46 rotatably supported by the motor stator 40 so as to be integrally rotatable. .

  Specifically, the motor stator 40 includes a stator core 44 fitted and fixed to the outside of the stator support tube portion 42. The stator support cylinder portion 42 includes a plurality of teeth (not shown) along the circumferential direction, and has a structure in which an electromagnetic coil (not shown) is wound around the teeth.

  As shown in FIG. 6, a fixed flange 42 </ b> F projecting to the side is provided on a portion of the stator support tube portion 42 that protrudes from the one end surface of the stator core 44 toward the case bottom wall 13. On the other hand, the case bottom wall 13 is provided with a conical pedestal portion 23 for fixing the stator support cylinder portion 42. The cone-shaped pedestal portion 23 has a truncated cone shape in which a part of the case bottom wall 13 is raised toward the inside of the fan case 12, and a center hole 24 is formed through the center of the cone-shaped pedestal portion 23. . A fixing flange 42F of the stator support cylinder 42 is assigned to a flat portion around the center hole 24 in the conical base 23 and screwed.

  Further, the end portion on the case bottom wall 13 side of the stator support tube portion 42 is formed with a diameter-enlarged chamber 42 </ b> A by expanding the inside in a stepped shape. A cap 41 is fitted in the enlarged diameter chamber 42A, and the closed end of the cap 41 protrudes from the fixed flange 42F. Then, the protruding portion is fitted into the center hole 24, so that the stator support tube portion 42 is positioned with respect to the case bottom wall 13.

  Inside the stator support cylinder portion 42, a metal bearing 45 is fitted to a portion excluding the diameter expansion chamber 42A. The motor drive shaft 46 is rotatably inserted inside the enlarged diameter chamber 42A, and one end portion projects toward the enlarged diameter chamber 42A, and a retaining disc 43 is fixed to the projected portion.

  The motor rotor 50 has a structure in which one end of a cylindrical tube wall 50A is closed by a disk wall 50B. The cylindrical wall 50A is magnetized so as to have a plurality of magnetic poles in the circumferential direction. Further, the disk wall 50B is fixed to the middle of a portion of the motor drive shaft 46 that protrudes from the stator support cylinder portion 42 to the opposite side of the case bottom wall 13 so as to be integrally rotatable. It is fixed so that it can rotate together. Specifically, the motor rotor 50 is fixed to the motor drive shaft 46 by, for example, an interference fit. On the other hand, the multiblade fan 11 is fitted to each other so that the cross-sectional shape of the hole in the shaft insertion tube portion 16D provided at the center of the cylindrical portion 16 and the cross-sectional shape of the tip portion of the motor drive shaft 46 are both the same non-circular shape. It is fixed by combining.

  The motor rotor 50 and the retaining disc 43 are provided with sliding washers 44A and 44B at portions facing the end face of the metal bearing 45, respectively.

  As shown in FIG. 6, the motor control board 60 of the brushless motor 30 has a central through hole 61 that is loosely fitted to the outside of the portion of the motor stator 40 that is fixed to the case bottom wall 13 (ie, the fixed flange 42F). Is formed. The central through hole 61 is disposed with a gap between the case bottom wall 13 and the multiblade fan 11, and the motor control board 60 has a conical shape in the axial direction of the motor drive shaft 46. It is arranged between the end surface of the pedestal 23 and the end surface of the motor rotor 50. The motor control board 60 is fixed to the case bottom wall 13 via a plurality of fixed columns 64 (see FIG. 4).

  Further, as shown in FIG. 4, the motor control board 60 has a disk shape that is substantially the same size as the outer shape of the rotary hook part 16 </ b> C of the multiblade fan 11. And the outer edge part of the motor control board 60 is overlaid on the outer edge part of the rotating collar part 16C.

  In order to detect the rotational position of the motor rotor 50, for example, three Hall elements 62 (corresponding to “position detection elements” of the present invention) are mounted on the motor control board 60. These Hall elements 62 are arranged at predetermined intervals in the circumferential direction in the rotor facing annular region of the motor control board 60 that faces the end face of the motor rotor 50. Then, the phase of the motor rotor 50 is detected based on the magnetic flux intensity received by each of the Hall elements 62.

  An inverter circuit for generating a three-phase AC motor drive current corresponding to the phase of the motor rotor 50 is mounted on the motor control board 60. This inverter circuit is a general circuit in which six FETs 63 are bridge-connected. These FET 63 groups are arranged near the discharge port 15 in the motor control board 60. Here, the part which connected the edge parts by the side of the fan accommodating part 12A among the 1st duct side wall 12C and the 2nd duct side wall 12D of the discharge duct 12B is used as the opening end 15K in the inner surface of the fan case 12 among the discharge ports 15. Then, the FET 63 group faces the opening end 15K in a line with a gap. The Hall element 62 group and the FET 63 group are arranged on the surface of the motor control board 60 facing the multi-blade fan 11 as shown in FIGS. 6 and 7.

  As shown in FIG. 4, the central through hole 61 has an elliptical shape. The center of the central through hole 61 coincides with the center of the motor drive shaft 46, and the long axis of the central through hole 61 extends toward the discharge port 15. One end of the central through hole 61 in the long axis direction is disposed between the opening end 15 </ b> K of the discharge port 15 and the motor drive shaft 46. Further, as shown in FIG. 5, both end portions on the long axis side of the central through hole 61 are located in the above-described rotor-facing annular region of the motor control board 60. Thereby, a part of the annular gap 40 </ b> S between the inner peripheral surface of the motor rotor 50 and the outer peripheral surface of the stator core 44 faces the case bottom wall 13 through the central through hole 61. On the other hand, both ends of the central through hole 61 on the short axis side are located on the inner side of the rotor facing annular region and are adjacent to the fixing flange 42F.

  The description regarding the structure of the cooling fan apparatus 10 of this embodiment is above. Next, the effect of the cooling fan apparatus 10 is demonstrated. The cooling fan device 10 is attached to the wall surface of an industrial machine control box (not shown). Specifically, for example, a fan case is formed with a ventilation hole formed through the side wall of the control box, and the suction port 14 (see FIG. 1) of the cooling fan device 10 is opposed to the ventilation hole from the inside of the control box. 12 case fixing protrusions 12W group are fixed to the edge of the ventilation hole with bolts B. When the power of the control box is turned on, the cooling fan device 10 receives power from the control box, and the brushless motor 30 rotates the multiblade fan 11.

  When the multiblade fan 11 is driven to rotate, the air in the center of the fan case 12 is sent to the side of the fan case 12 to reduce the pressure in the center, and outside air is taken into the fan case 12 from the suction port 14. On the other hand, the pressure on the side in the fan case 12 increases, and the compressed air is discharged out of the fan case 12 through the discharge port 15. Thereby, outside air is taken in through the cooling fan apparatus 10 from the ventilation hole of a control box, and the heat source in a control box is cooled.

  In addition, you may attach the cooling fan apparatus 10 to a control box so that the air in a control box may be discharged | emitted by the cooling fan apparatus 10 outside.

  Now, when air passes through the fan case 12 from the suction port 14 to the discharge port 15, the air in the gap between the case bottom wall 13 of the fan case 12 and the multiblade fan 11 also moves toward the discharge port 15. Flowing. Thereby, the heat of the motor control board 60 arrange | positioned in the clearance gap between the case bottom wall 13 and the multiblade fan 11 is removed. Then, the air flowing through the gap between the motor control board 60 and the case bottom wall 13 hits the inclined side surface 23A of the conical pedestal portion 23 in the fixed portion between the motor stator 40 and the case bottom wall 13, and the motor passes through the central through hole 61. It flows toward the stator 40. Here, since the central through-hole 61 is open to the rotor facing annular region of the motor control board 60 that faces the end surface of the motor rotor 50, the central through hole 61 is between the inner surface of the motor rotor 50 and the outer surface of the motor stator 40. Air that has passed through the central through hole 61 easily flows into the annular gap 40S. In addition, since one end of the central through hole 61 in the long axis direction is disposed between the motor stator 40 and the opening end 15K on the inner surface of the fan case 12 in the discharge port 15, the motor control board is efficiently provided. The air moving through the gap between 60 and the case bottom wall 13 can be directed from the central through hole 61 to the motor stator 40.

  As a result, the air around the motor stator 40 flows, the heat of the motor stator 40 can be efficiently removed, the abnormal heat generation of the brushless motor 30 can be prevented, and the output of the brushless motor 30 can be prevented. It is possible to increase the amount of blown air by increasing the rotational speed. Further, since the FET 63 of the motor control board 60 is disposed between the discharge port 15 and the motor stator 40 in the motor control board 60, the heat of the FET 63 can be prevented from moving toward the motor stator 40, and the discharge port The FET 63 group can be cooled by the air collected on the 15 side. Furthermore, in the present embodiment, by disposing the Hall element 62 groups on both sides of the central through hole 61 in the short direction, the distance from the Hall element 62 group to the opening edge of the central through hole 61 in the motor control board 60 is increased. As a result, the strength of the vicinity of the Hall element 62 in the motor control board 60 can be sufficiently secured.

[Second Embodiment]
FIG. 8 shows a cooling fan device 10V according to the second embodiment of the present invention. This cooling fan device 10V differs from the first embodiment only in that a pair of guide protrusions 70 and 70 protrude from the motor control board 60 toward the case bottom wall 13. Specifically, the pair of guide protrusions 70 are formed by, for example, cutting a prismatic resin material into a predetermined length and bonding it to the motor control board 60. The pair of guide protrusions 70, 70 are arranged on the side away from the discharge port 15, extend from the outer edge of the motor control board 60 to the opening edge of the central through hole 61, and toward the central through hole 61. Are close to each other. The configuration of the cooling fan device 10V of the present embodiment is as described above. According to this configuration, the air flowing between the motor control board 60 and the case bottom wall 13 is collected by the guide protrusions 70 and 70 and the central through hole 61 is collected. To the motor stator 40, and the efficiency of heat removal of the motor stator 40 is further improved.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.

  (1) In the first and second embodiments, the central through hole 61 has an elliptical shape. However, the central through hole according to the present invention is a rotor-facing circle that faces the end face of the motor rotor in the motor control board. Any shape including the central through holes 71, 72, 73, 74 illustrated in the following (2) to (5) may be used as long as the ring region is opened.

  (2) The central through hole 71 of the modification according to the present invention shown in FIG. 9A is formed in the circular hole 71A having a size intermediate between the outer diameter of the fixing flange 42F and the inner diameter of the motor rotor 50. The center through-hole 61 of one embodiment is overlapped, and a pair of elliptically curved portions 71B and 71B are projected from the circular hole portion 71A.

  (3) The central through hole 72 of the modification according to the present invention shown in FIG. 9B protrudes from the pair of elliptic curved portions 72B and 72B from the circular hole portion 72A having the same size as the inner diameter of the motor rotor 50. The shape is

  (4) In the modification according to the present invention shown in FIG. 10 (A), the Hall element 62 group is arranged on the outer edge side from the center of the width of the rotor-facing annular region, and the central through hole 73 has the rotor-facing annular ring. It is a circular hole that opens to the center of the width of the region.

  (5) In the modification according to the present invention shown in FIG. 10 (B), the Hall element 62 groups are gathered together at equal intervals in the circumferential direction of the rotor facing annular region, and the inner diameter of the central through hole 74 is set to the Hall element 62. A small diameter portion 74B is provided inside the region where the group is gathered, and a small diameter portion 74B is provided. In the other portion, the inner diameter of the central through hole 74 is opened to the center of the width of the rotor facing annular region, and a large diameter portion 74A is provided. It has a structure.

  (6) In the above embodiment, the central through hole 61 has an elliptical shape. However, for example, it may have a substantially long hole shape, a substantially rectangular shape, or a shape as shown in FIG. . Even with such a configuration, the strength of the vicinity of the Hall element 62 in the motor control board 60 can be sufficiently secured. Moreover, even if the central through hole has a shape as shown in FIG. 10B, the same effect can be obtained.

  (7) In the above embodiment, the fixed portion between the motor stator 40 and the case bottom wall 13 is composed of a plurality of members (that is, the weight-shaped pedestal portion 23, the stator support cylinder portion 42, and the cap 41). May be an integrally molded product (for example, a die-cast integral molded product) or a resin integral molded product.

10, 10V Cooling fan device 11 Multi-blade fan 12 Fan case 13 Case bottom wall 14 Suction port 15 Discharge port 16 Tube portion 17 Blade plate 23 Conical pedestal portion 23A Inclined side surface 30 Brushless motor 40 Motor stator 42F Fixed flange 44 Stator core 50 Motor rotor 60 Motor control board 61, 71, 72, 73, 74 Central through hole 62 Hall element (position detection element)
63 FET
70 Guide protrusion

Claims (6)

The multiblade fan (11) is rotationally driven by a brushless motor (30), and the side surface from the suction port (14) on one end surface of the fan case (12) housing the multiblade fan (11) and the brushless motor (30) In the cooling fan device (10, 10V) for supplying air to the discharge port (15) of
The motor rotor (50) of the brushless motor (30) is arranged in a cylinder (16) in the center of the multi-blade fan (11) in a cylindrical shape,
The motor stator (40) of the brushless motor (30) is disposed inside the motor rotor (50), and the case bottom wall (13) opposite to the suction port (14) in the fan case (12). To one end of the motor stator (40),
Central through-holes (61, 71, 72, loosely fitted on the motor control board (60) of the brushless motor (30), which are loosely fitted outside the fixed portion between the motor stator (40) and the case bottom wall (13). 73, 74), the motor control board (60) is disposed in a state having a gap between the case bottom wall (13) and the multi-blade fan (11), and the motor control board (60). ), A position detection element (62) for detecting the rotational position of the motor rotor (50) is mounted on the rotor-facing annular region facing the end surface of the motor rotor (50). The cooling fan device (10, 10V), wherein the central through hole (61, 71, 72, 73, 74) is opened to a portion where the position detecting element (62) is not disposed.   A conical pedestal portion (23) is provided which protrudes from the case bottom wall (13) in a conical shape and is fixed at one end surface of the motor stator (40) at the tip, and an inclined side surface of the conical pedestal portion (23). (23A) allows air between the motor control board (60) and the case bottom wall (13) to enter the motor rotor (50) from the central through hole (61, 71, 72, 73, 74). The cooling fan device (10, 10V) according to claim 1, wherein the cooling fan device can be guided.   Air that protrudes from either the motor control board (60) or the case bottom wall (13) toward the other and flows between the motor control board (60) and the case bottom wall (13) is the center. The cooling fan device (10) according to claim 1 or 2, further comprising a guide protrusion (70) for guiding the guide so as to gather on the through hole (61) side.   The cooling fan device (10, 10V) according to any one of claims 1 to 3, wherein the central through hole (61, 71) has a shape elongated in one direction.   One end in the longitudinal direction of the central through hole (61, 71) is between the motor stator (40) and the opening end (15K) on the inner surface of the fan case (12) of the discharge port (15). The cooling fan device (10, 10V) according to claim 4, wherein the cooling fan device is arranged.   An FET (63) of an inverter circuit for generating a motor drive current is arranged between the discharge port (15) and the motor stator (40) in the motor control board (60). The cooling fan device (10V) according to claim 5.

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