JP5152703B2 - Centrifugal fan - Google Patents

Description

  The present invention relates to a centrifugal fan used in an apparatus cooling device.

  Conventionally, a housing intended for mobile devices has no room for installing a cooling device for cooling a CPU or the like, so a plurality of cases such as a double-sided air intake that enables thin and efficient cooling. A centrifugal fan with an intake structure was used as a cooling device. For this reason, air inlets are arranged on both sides of the front and back, and the height of the fan and motor is kept low, so that water easily enters, and when the water that has entered reaches the charging part and the bearing part, it breaks down.

  In order to solve such a problem, a centrifugal fan having a waterproof structure is disclosed (Patent Document 1).

Japanese Patent No. 3694224

  However, in the configuration of the centrifugal fan disclosed in Patent Document 1, the height direction of the centrifugal fan cannot be accommodated in the casing due to its size, and the waterproof property is not sufficient. However, it did not have toughness such as light weight and waterproofness.

  SUMMARY OF THE INVENTION Accordingly, the present invention solves the above-described problems, and an object of the present invention is to provide a centrifugal fan excellent in waterproofness having a multiple intake structure that does not impair cooling performance and a structure that suppresses the height of the entire centrifugal fan. And

In the centrifugal fan of the invention of claim 1, a rotating impeller in which a plurality of blades are formed on the circumferential portion of a cup-shaped boss to which a motor rotor is attached, a bottomed case surrounding the impeller, A cover that covers the opening of the case, a spoke that is connected to the periphery of the case, and an island-shaped motor mounting wall on which the motor is installed, and a motor mounting wall of the case and the peripheral portion thereof. a first intake port that is, to face the first intake port, and a second intake port formed in the cover, between the rotor and the blade, and the outer peripheral portion of the boss A gap of a labyrinth structure composed of a plurality of ridges provided alternately on the outer peripheral part of the motor mounting wall is formed, and a ring member is provided on at least one of the ridges, and a part of the gap is wide. portion To form a narrow section, the wider portion of the gap, by the inclined portion formed on the ring member, characterized in that the bag-like portion which is inner side is wider than the inlet side of the gap.

  According to the first aspect of the present invention, sufficient waterproofness can be obtained even in a centrifugal fan having a multiple intake structure such as double-sided intake and a structure in which the height of the entire centrifugal fan is kept low.

It is a perspective view of the centrifugal fan in 1st Example of this invention. It is a bottom view of a centrifugal fan same as the above. It is a perspective view of an impeller same as the above. It is the perspective view which displayed the case and the motor same as the above. It is sectional drawing of a centrifugal fan same as the above. Same as above, results of waterproof test. It is the table | surface which showed the kind of protection grade with respect to water same as the above.

  Hereinafter, preferred embodiments of a centrifugal fan according to the present invention will be described with reference to the accompanying drawings.

  The overall configuration of the centrifugal fan of this embodiment will be described with reference to FIGS. 1 to 5. Reference numeral 1 denotes a rotating impeller, and reference numeral 2 denotes a casing having the impeller 1 therein. The impeller 1 includes a plurality of blades 3 and cup-shaped bosses 4, and the blade 3 as a centrifugal fan main body is radially formed on the circumferential portion of the boss 4 that forms the center of the impeller 1. Formed. Further, a motor 5 serving as a driving unit for the impeller 1 is disposed inside the boss 4. The motor 5 includes a stator 6 having an iron core (core) on which windings are mounted, a rotor (yoke) 7 attached to the inner peripheral portion of the boss 4 and rotated by a magnetic force from the stator 6, the stator 6 and other Each element is mounted and configured by a circuit board 8 as a charging unit constituting an electric circuit as the motor 5.

  The casing 2 that forms the outline of the centrifugal fan includes a bottomed case 9 that surrounds the impeller 1 and a cover 10 that covers the upper opening of the case 9, both of which are formed of members having excellent heat conductivity. The Further, the case 9 is formed with an island-shaped motor mounting wall 12 connected to the periphery thereof by spokes 11. The motor 5 is installed on the motor mounting wall 12, and the motor 5 except for the motor mounting wall 12 side is installed. Almost the entire surface is surrounded by a cup-shaped boss 4. More specifically, a cylindrical bearing 13 is erected substantially at the center of the motor mounting wall 12 which is a motor 5 mounting portion, while a shaft 14 which is a rotating shaft is mounted at the center of the boss 4. The shaft 14 is rotatably supported by the bearing 13.

  The rotor 7 and the impeller 1 around the shaft 14 are rotated by the electromagnetic action of the magnet 15 attached to the inner peripheral surface of the rotor 7 and the stator 6 facing the magnet 15. Reference numeral 16 denotes a lead wire for electrical connection with the stator 6.

  The impeller 1 is rotatably mounted by a bearing 13 and a shaft 14, and a rotor 7 is provided inside the impeller 1, and the rotor 7 has a positional relationship facing the outer periphery of the stator 6. . The rotor 7 rotates with the fan by the rotating magnetic field of the stator 6 so that wind is generated.

  The motor mounting wall 12 forms a part of the case 9, and the case 9 is formed with an exhaust port 17 and a casing 2 in the discharge direction of the impeller 1. Further, the case 9 is formed with a first air inlet 18 in a direction perpendicular to the discharge direction of the impeller 1, and the cover 10 attached to the case 9 is opposed to the first air inlet 18. However, another second air inlet 19 is formed in a direction perpendicular to the discharge direction of the impeller 1. The first air inlet 18 is formed by partially connecting the motor mounting wall 12 of the case 9 and the peripheral portion with the spoke 11. Further, the opening area of each intake port 18 and 19 may be appropriately determined in consideration of the suction amount of each intake port 18 and 19.

  Subsequently, the outer periphery of the boss 4 is arranged concentrically with the shaft 14 and is arranged in parallel in the radial direction of the shaft 14 at a predetermined interval, and the axial direction of the shaft 14 projects toward the motor mounting wall 12 side. Two first and second ridges 20 and 21 formed by two cylindrical ribs are formed integrally. On the other hand, the outer peripheral portion of the motor mounting wall 12 is disposed concentrically with the shaft 14 and is arranged in parallel with a predetermined interval in the radial direction of the shaft 14, and the axial direction of the shaft 14 projects toward the boss 4 side. Two third and fourth protrusions 22 and 23 formed of two cylindrical ribs are formed integrally.

  As shown in FIG. 5, the fourth ridge portion 23 is waterproofed to the distal end side of the fourth ridge portion 23 so as to cover the distal end side of the fourth ridge portion 23 and half of the outer periphery of the distal end side. A ring 24 is fitted and attached.

  The waterproof ring 24 is an annular body having a substantially inverted L-shaped cross section, and the motor mounting wall extends in the axial direction of the shaft 14 such that the bottom surface facing the motor mounting wall 12 is directed radially outward of the shaft 14. It is formed as a tapered inclined portion 25 close to the 12 side.

  Here, the waterproof ring 24 is substantially the same in outer diameter in the radial direction of the shaft 14 with the stepped portion 26 projecting in an annular shape on the outer periphery of the base end of the fourth protrusion 23 on the motor mounting wall 12 side. A cylindrical body 27 concentric with the third protrusion 22 is constituted by the waterproof ring 24 and the fourth protrusion 23. In the middle in the axial direction of the outer peripheral surface of the cylindrical body 27, an annular groove 28 that is surrounded by the bottom surface portion of the waterproof ring 24, the outer peripheral surface of the fourth protrusion 23 and the step portion 26, and concentric with the shaft 14. It has. The cross-sectional shape of the annular groove 28 in the axial direction of the shaft 14 is such that the opening area extends from the opening edge disposed on the outer peripheral surface of the cylindrical body 27 toward the radially inner side of the shaft 14, and the inclined portion 25 of the waterproof ring 24. The shape gradually increases along the inclination.

  Here, between the rotor 7 and the blade 3 of the impeller 1, the first and second protrusions 20, 21 provided on the outer periphery of the boss 4 and the first provided on the outer periphery of the motor mounting wall 12 are provided. The three ridges 22 and the cylindrical body 27 (the fourth ridges 23 and the waterproof ring 24) are in a non-contact state with respect to the radial direction of the shaft 14 alternately and at a predetermined interval. The labyrinth structure 29 is formed side by side with respect to the motor 5 installed on the motor mounting wall 12 formed in the abutting portion 30 between the outer peripheral portion of the boss 4 and the outer peripheral portion of the motor mounting wall 12. The gap 31 for allowing the fan to rotate is formed in a gap shape in which irregularities are continuously formed in the radial direction of the shaft 14.

  In the gap 31 between the first protrusion 20 and the cylindrical body 27, a narrow part 32 formed between the inner peripheral surface of the first protrusion 20 and the waterproof ring 24 or the step part 26, A wide portion 33 formed between the inner peripheral surface of the first protrusion 20 and the outer peripheral surface of the third protrusion 22 in the annular groove 28 is provided. The gap 31 includes a wide portion 33 and an inclined portion 25 formed on the end face of the waterproof ring 24 so that the annular groove 28 constituting a part of the gap 31 has a deeper inner side than the inlet side in the radially outer direction. A bag-like portion 34 having a wide side is formed.

  Here, the inclined portion 25 is an outer peripheral portion 25 </ b> A that is a side close to the gap 31 in the bottom surface portion of the waterproof ring 24, which is a facing portion facing the flow direction F of a fluid such as water that has entered the gap 31 from the butt portion 30. It is formed so as to be inclined from the upstream side to the downstream side in the flow direction F from the inner peripheral portion 25 </ b> B that is far from the inner circumferential portion.

  Next, the operation of the above configuration will be described. The centrifugal fan in this embodiment is mounted in a casing of a mobile device (not shown) in order to cool a heat-generating component mounted on a mobile device such as a notebook personal computer. Then, when electric power is supplied to the stator 6 of the motor 5 and the impeller 1 is rotated in the direction of the arrow by the electromagnetic action of the stator 6 and the magnet 15 attached to the inner peripheral surface of the rotor 7, Warm air existing in the gap 31 between the upper surface of the casing 2 and the lower surface of the casing and the casing 2 is sucked from the intake ports 18 and 19, respectively. The air taken in from the intake ports 18 and 19 circulates outside the impeller 1 to reach the exhaust port 17, from which it is discharged to the outside of the centrifugal fan and the casing.

  Subsequently, the first and second protrusions 20 and 21 provided on the outer periphery of the boss 4, the third protrusion 22 provided on the outer periphery of the motor mounting wall 12, and the cylindrical body 27 (fourth The protrusions 23 and the waterproof ring 24) are provided with labyrinth structures 29 arranged alternately in the radial direction of the shaft 14 at predetermined intervals, and the outer periphery of the boss 4 and the outer periphery of the motor mounting wall 12 By forming the gap 31 between the outer peripheral portion of the boss 4 and the outer peripheral portion of the motor mounting wall 12 by forming the gap 31 between the outer peripheral portion of the boss 4 and the outer peripheral portion of the motor mounting wall 12 by forming the gap 31 with the unevenness continuously formed in the radial direction of the shaft 14. Water is prevented from entering the space formed between the boss 4 and the motor mounting wall 12 from the gap 31 formed in the above. For the water that has entered from the abutting portion 30 between the outer peripheral portion of the boss 4 and the outer peripheral portion of the motor mounting wall 12 to the middle of the gap 31 of the labyrinth structure 29, the first and second protrusions 20, 21, the third protrusion 22, and the cylindrical body 27 (the fourth protrusion 23 and the waterproof ring 24), the water that has entered through the groove-shaped gap 31 is used as the circumference of the centrifugal fan. The water is discharged to the outside through the gap 31 corresponding to the portion where the installation posture is lowered on either the case 9 side or the cover 10 side of the casing 2 by flowing in the direction. As a result, the water 5 that has entered the gap 31 between the outer peripheral portion of the boss 4 and the outer peripheral portion of the motor mounting wall 12 through the gap 31 is provided in the space surrounded by the boss 4 and the motor mounting wall 12. Can be prevented.

  In addition, the labyrinth structure 29 includes first and second protrusions 20 and 21 provided on the outer periphery of the boss 4, a third protrusion 22 and a cylindrical body provided on the outer periphery of the motor mounting wall 12. 27 (fourth protrusions 23 and waterproof ring 24) are arranged in a staggered manner and at a predetermined interval in the radial direction of the shaft 14, and the labyrinth structure 29 is used as the rotor 7 of the impeller 1. And the blade 3 prevents the shape of the butted portion 30 between the outer peripheral portion of the boss 4 and the outer peripheral portion of the motor mounting wall 12 from increasing in the axial direction of the shaft 14. Both sides of the air intake is possible while keeping the height of the air low.

  Further, a waterproof ring 24 is attached to the distal end side of the fourth protrusion 23, and the inner periphery of the first protrusion 20 facing the fourth protrusion 23 and the radially outer side of the shaft 14. Since the bag-like portion 34 is formed in a part of the gap 31 of the labyrinth structure 29 constituted by the surface, the water that has entered the gap 31 between the first ridge portion 20 and the fourth ridge portion 23. Is trapped by the bag-shaped portion 34, and the inclined portion 25 formed in the waterproof ring 24 serves as a check valve for preventing the backflow of water trapped in the bag-shaped portion 34 to return to the gap 31. Since the water trapped in the bag-like portion 34 is quickly discharged to the outside of the gap 31, the flow of the water that has entered the gap 31 in the circumferential direction is further improved, so that more water is stored in the labyrinth structure 29. Even if it has entered the gap 31, the outside of the gap 31 through the bag-like portion 34 To provide a centrifugal fan excellent in waterproofness because it can be discharged and the flow of water toward the motor 5 or the bearing 13 provided in the space surrounded by the boss 4 and the motor mounting wall 12 can be suppressed. Can do. Here, the waterproofness of the centrifugal fan of the present embodiment is as shown in FIG. 6 in the waterproof test in which the water drop dropping direction is the exhaust port 17, the first intake port 18, or the second intake port 19. In either case, protection grades 2 and 3 are achieved. Here, FIG. 7 shows the definition of each protection class.

  The embodiment corresponds to claim 1, and the first and second protrusions 20, 21 provided on the outer peripheral part of the boss 4 as a plurality of protrusions between the rotor 7 and the blade 3, The third ridge 22 and the cylindrical body 27 (fourth ridge 23 and waterproof ring 24) provided on the outer peripheral portion of the motor mounting wall 12 are arranged alternately at a predetermined interval with the shaft 14. The gap 31 of the labyrinth structure 29 formed in parallel with each other in the radial direction is formed, and the fourth ridge which is at least one of the ridge portions 20, 21, 22, 23 is formed. A waterproof ring 24 is provided as a ring member in the portion 23, and as a part of the gap 31, a wide part 33 and a narrow part as a wide part in the gap 31 between the first ridge part 20 and the fourth ridge part 23. While forming the narrow part 32, the wide part 33 is connected to the end face part of the waterproof ring 24. The bottom surface portion that is opposite to the motor mounting wall 12 and faces the flow direction F of a fluid such as water that can flow through the gap 31 that has entered the gap 31 from the abutting portion 30 is closer to the gap 31. A bag-like portion 34 that is formed so that the back side is wider than the inlet side of the gap 31 by the inclined portion 25 that is inclined from the upstream side to the downstream side in the flow direction F toward the inner peripheral portion 25B that is far from the outer peripheral portion 25A. It is said.

  In this case, the labyrinth structure 29 composed of a plurality of cylindrical protrusions 20, 21, 22, and 23 minimizes intrusion of water from the abutting portion 30 between the outer periphery of the boss 4 and the outer periphery of the motor mounting wall 12. However, the water that has entered the middle of the gap 31 of the labyrinth structure 29 is stopped as much as possible, and the first and second protrusions 20 and 21, the third protrusion 22 and the cylindrical body 27 (fourth Water that has entered through the groove-like gap 31 constituted by the protrusion 23 and the waterproof ring 24) flows in the circumferential direction, and the water is discharged to the outside from a portion that is lowered in the installation posture. Further, it is possible to prevent the water that has entered from reaching the circuit board 8 or the bearing 13. Since the labyrinth structure 29 is formed between the rotor 7 and the blade 3 of the impeller 1, the height of the entire centrifugal fan can be kept low and a double-sided intake structure can be adopted. Further, a wide bag-like portion 34 is formed in a groove-like gap 31 formed by attaching the waterproof ring 24 to the distal end side of the fourth protrusion 23 and facing the first protrusion 20. Therefore, the circumferential flow of the invading water is further improved, and even when more water enters the labyrinth structure 29, the water can be discharged to the outside through the bag-like portion 34 having the gap 31 formed wide. In addition, since the flow of water in the direction of the circuit board 8 or the bearing 13 can be suppressed, a centrifugal fan excellent in waterproofness can be provided. Therefore, the height of the entire centrifugal fan and the multiple intake structure such as double-sided intake including the multiple intake portions of the first intake port 18 and the second intake port 19 in the casing 2 that forms the outline of the centrifugal fan are suppressed. Even in a centrifugal fan having a structure, sufficient waterproofness can be obtained.

  In addition, this invention is not limited to the said Example, It can change in the range which does not deviate from the meaning of this invention. For example, the number of protrusions provided on the boss 4 or the motor mounting wall 12 is not limited to two and can be changed as appropriate. In addition, by making the number of protrusions provided on the boss 4 or the motor mounting wall 12 a plurality of three or more, the shape of the gap 31 by the labyrinth structure 29 is further complicated, so that the centrifugal fan It is also possible to further improve waterproofness. Further, the shape of the waterproof ring 24, particularly the inclined portion 25, can be changed as appropriate.

1 impeller 3 blade
4 Boss
5 Motor 7 Rotor
9 cases
10 Cover
11 spokes
12 Motor mounting wall
18 First inlet
19 2nd inlet port 20 1st protrusion part 21 2nd protrusion part 22 3rd protrusion part 23 4th protrusion part
24 Waterproof ring (ring member)
25 Inclined part 29 Labyrinth structure 31 Gap 32 Narrow part (narrow part)
33 Wide part (wide part)
34 Bag-shaped part

Claims (1)

A rotating impeller having a plurality of blades formed on a circumferential portion of a cup-shaped boss to which a motor rotor is attached; a bottomed case surrounding the impeller; a cover covering an opening of the case; The case is connected to the periphery thereof by spokes, and an island-shaped motor mounting wall on which the motor is installed, a first air inlet formed between the motor mounting wall of the case and the periphery, and A second air inlet formed in the cover facing the first air inlet,
Between the rotor and the blade, thereby forming a gap labyrinth structure comprising a plurality of protrusions which are alternately arranged on the outer peripheral part of the outer peripheral portion and the motor mounting wall of the boss, at least the ridges A ring member is provided in one, and a wide portion and a narrow portion are formed in a part of the gap, and the wide portion of the gap is formed on the inner side of the gap by an inclined portion formed on the ring member. A centrifugal fan characterized by having a wide bag-shaped portion.

Images