Cooling fan

Abstract

The present invention relates to a cooling fan having a waterproof structure of a printed circuit board (PCB) on which a motor driving circuit is mounted. The cooling fan of the present invention is characterized by comprising: a fan housing forming an air discharge port discharging air at a front surface and an air inflow port allowing air to flow in at a back surface; a rotating shaft supported in a rotatable manner by the fan housing at a lower portion; a rotor fixed to an upper portion of the rotating shaft; a stator disposed at an inner side of the rotor with a predetermined interval from the rotor; an impeller connected to an outer periphery of the rotor and rotating together with the rotor; a printed circuit board disposed at a lower side of the stator, connecting a power source to the stator, and mounting various circuit components for controlling the motor driving circuit of the cooling fan; and a printed circuit board housing box connected to the back surface of the fan housing by a plurality of bridge portions, for housing the printed circuit board at a center, the coil of the stator and the printed circuit board being electrically connected by a pin terminal, the pin terminal being connected and fixed by being welded at an upper end, the lower end of the pin terminal being connected to the printed circuit board located inside the printed circuit board housing box by a waterproof rubber plate and the printed circuit board housing box.

Description

TECHNICAL FIELD

[0001] The present application relates to a cooling fan, and more particularly, to a cooling fan having a waterproof structure of a printed circuit board (PCB) in which a motor driving circuit is installed. BACKGROUND

[0002] A cooling fan is installed in an electrical component of a computer or the like electronic device, a light emitting diode lighting, or an automobile, and is mainly used to prevent various electronic components such as a microprocessor from overheating.

[0003] A cooling fan disclosed in Korean Patent Laid-Open Publication No. 10-2019-0066898 (Patent Document 1) includes a rotating shaft rotatably supported by a fan housing, a rotor fixed to the rotating shaft, a stator fixed to the fan housing and disposed at a predetermined interval from the rotor, an impeller fixed to the rotor and rotating together with the rotor, and a printed circuit board disposed at a lower portion of the stator and installed with a motor driving circuit for controlling the cooling fan.

[0004] In the cooling fan of Patent Document 1, the printed circuit board in which the motor driving circuit is installed is assembled in a state of being exposed to the outside of the housing. Therefore, when the cooling fan is used by being built in the inside of a housing of an electronic device, a waterproof problem does not occur.

[0005] However, when the cooling fan is used in a state of being exposed to an external environment such as rain, wind, and snow, especially, in a rainy season or a heavy snowfall, the motor driving circuit of the cooling fan can be easily affected by waterproofing.

[0006] Also, for a general motor, after a pin terminal is pressed into a wire shaft and a coil wound around a stator core is wound around a lower end of the pin terminal, the lower end of the pin terminal is inserted into an insertion hole of a printed circuit board in which the motor driving circuit is installed and a lower surface of the printed circuit board is dipped to be fixed, thereby fixing the lower end of the pin terminal to the printed circuit board.

[0007] As described above, a structure in which the lower end of the pin terminal is inserted into a large-sized insertion hole of the printed circuit board in a state of winding the coil around the lower end of the pin terminal is not sufficient to achieve face waterproofing of the printed circuit board.

[0008] On the other hand, the existing cooling fan does not have any protective net at an air discharge port on an upper side of the impeller. Therefore, when a user does not notice, an accident can occur and foreign substances can penetrate into the air discharge port and collide with the impeller.

[0009] Generally, the cooling fan can be used for heat dissipation of important components such as a microprocessor (CPU), and when the cooling fan malfunctions, the microprocessor, which is the most important element of a control electronic circuit or a control system, can be hindered from normal operation or a malfunction can occur. SUMMARY

[0010] TECHNICAL PROBLEM

[0011] Therefore, the present application has been proposed to solve the above problems of the prior art, and an object of the present application is to provide a cooling fan having a waterproof structure in which a printed circuit board (PCB) housing is provided in a fan housing, and a PCB on which a motor driving circuit is mounted is assembled, thereby separating a coil end of a stator from a PCB structure.

[0012] Another object of the present application is to provide a cooling fan in which an assembly of a protective net to a fan housing is easily achieved by pressing a coupling ring of the protective net into a coupling hole of the fan housing and fastening an anti-vibration coupling member through the coupling ring and the coupling hole.

[0013] TECHNICAL SOLUTION

[0014] To achieve the above object, a cooling fan according to an embodiment of the present application is characterized by including: a fan housing in which an air discharge hole through which air is discharged is formed in a front surface, and an air inflow hole through which air flows in is formed in a back surface; a rotating shaft which is rotatably supported by the fan housing at a lower portion; a rotor which is fixed to an upper portion of the rotating shaft; a stator which is disposed at an inner side of the rotor with a predetermined interval from the rotor; an impeller which is connected to an outer periphery of the rotor and rotates together with the rotor; a printed circuit board which is disposed at a lower side of the stator, connects a power source to the stator, and has various circuit components for controlling a motor driving circuit of the cooling fan mounted; and a printed circuit board housing which is connected to the back surface of the fan housing by a plurality of bridge portions, and is used to house the printed circuit board at a center, in which an electrical connection between a coil of the stator and the printed circuit board is achieved by a pin terminal, the pin terminal is fixed by being welded at an upper end, and a lower end of the pin terminal is connected to the printed circuit board which is located inside the printed circuit board housing by a waterproof rubber plate and the printed circuit board housing.

[0015] A waterproof molding material can be formed at a lower side of the printed circuit board housing, and a cover portion can be assembled at a lower portion of the printed circuit board housing.

[0016] Also, the printed circuit board housing can include: a disc portion in which the stator is placed at an upper portion; a circular wall which extends downward from an outer periphery portion of the disc portion, and forms a circular housing groove at an inside; and a plurality of bridge portions which are connected between the circular wall and the fan housing, one of the plurality of bridge portions including a plate-shaped bridge portion having a housing groove structure to house an output terminal connected to the printed circuit board.

[0017] The cooling fan of the present application can further include: a bearing housing having a stator fixed to an outer circumferential portion and having an upper bearing and a lower bearing rotatably supporting a rotating shaft at an inner circumferential portion; a first extension portion extending downward from a through-hole formed at the center of a disc portion of a printed circuit board housing case along a lower end portion of the bearing housing to increase an area of contact with the lower end portion of the bearing housing; and a second extension portion extending upward from a through-hole formed at the center of a cover portion coupled to a bottom surface of the printed circuit board housing case along the lower end portion of the bearing housing.

[0018] Further, a plurality of guides for receiving a protective tape of output terminals at the bottom portion can be protrusively formed at the plate-shaped bridge portion of the printed circuit board housing case, and the cover portion of the printed circuit board housing case is assembled to be snap-coupled to the printed circuit board housing case and the plate-shaped bridge portion.

[0019] Furthermore, the cooling fan can be configured of a single phase motor having one coil, and connection of the coil of the stator to a printed circuit board assembled at the printed circuit board housing case is implemented using three pin terminals to respectively connect a start terminal, an end terminal, and a ground terminal of the one coil.

[0020] The pin terminals can penetrate the upper and lower insulators of the stator and be welded and fixed to the coil of the stator at upper end portions of the pin terminals in a press-fitted state, and lower end portions of the pin terminals are welded and fixed to the printed circuit board disposed at the printed circuit board housing case after passing through the disc portion of the printed circuit board housing case.

[0021] The cooling fan of the present application can further include a protective net having a plurality of holes formed at an upper side to prevent foreign substances from penetrating through an air discharge port at an upper side of the impeller.

[0022] In this case, the protective net can further include four coupling rings each having a ring shape and extending in a downward direction from a side of an outermost concentric circle portion in which the plurality of holes are formed, and the fan housing includes: a cylindrical portion receiving the rotor, the stator, the impeller, and the printed circuit board housing case; and four extension portions corresponding to the plurality of coupling rings and extending in a manner of forming a square at an outer circumferential portion of the cylindrical portion, four coupling holes coupling the four coupling rings being formed at four corners of the square.

[0023] The coupling rings can have a height difference structure in which an outer diameter of an outer circumferential portion gradually decreases toward a lower end, and the coupling holes have a height difference structure in which an inner diameter gradually decreases from an upper portion toward a lower portion, so as to correspond to the height difference structure of the outer circumferential portion of the coupling rings, the coupling rings being press-coupled to the upper portions of the coupling holes.

[0024] In this case, the four coupling rings can each include a first slit cut on one side of the ring, the four extensions can include a second slit, and the both ends can not be connected to each other but can be terminated apart from each other outside the coupling hole. The coupling ring and the coupling hole can be coupled to the anti-vibration coupling member through the first and second slits. The anti-vibration coupling member can have a through hole formed in the center portion and a flange formed in both end portions. The anti-vibration coupling member can transmit vibration generated by rotation of the impeller during driving of the cooling fan to the body on which the cooling fan is mounted.

[0025] Another feature of the cooling fan according to the present application can include a fan housing, a printed circuit board on which various circuit components forming a motor driving circuit are mounted, a printed circuit board housing case connected to the back of the fan housing through a plurality of bridge portions to house the printed circuit board in the center, a fan motor having a rotor and a stator as a single-phase motor type controlled by the motor driving circuit, an impeller formed integrally on the outer periphery of the rotor, a plurality of pin terminals having coils of the stator connected to upper end portions thereof and connected to the printed circuit board located inside the printed circuit board housing case through lower end portions thereof, and a waterproof rubber plate provided at an upper portion of the printed circuit board housing case, through which the lower end portions of the pin terminals pass before entering the printed circuit board housing case.

[0026] Effects of the Invention

[0027] As described above, in the present application, a cooling fan having a printed circuit board waterproof structure can be provided so that water can be prevented from leaking between coils of a stator and a printed circuit board on which a motor driving circuit is mounted through pin terminals.

[0028] First, in the present application, a sealing structure in which the coil end of the stator is separated from the printed circuit board is adopted by providing a printed circuit board housing case in which the printed circuit board is assembled in the fan housing.

[0029] Also, the coil can be fixed to the upper end of the pin terminal by welding, and the lower end of the pin terminal can be assembled to the printed circuit board located inside the printed circuit board housing case through the waterproof rubber plate and the printed circuit board housing case. Epoxy resin molding for sealing can be performed after the welding of the terminal, to provide a perfect waterproof structure.

[0030] In this case, if the lower end of the pin terminal is inserted into the printed circuit board insertion hole to be welded after the one end of the coil is wound around the lower end of the pin terminal, the welding surface is not always constant, so that water can leak to the waterproof rubber plate when epoxy resin is applied to the surface of the printed circuit board.

[0031] As described above, in this invention, when the coil is soldered and fixed to the upper end of the pin-shaped terminal and the lower end of the pin-shaped terminal is assembled onto the printed circuit board, the lower end of the pin-shaped terminal is assembled onto the printed circuit board located inside the printed circuit board housing in a state where it passes through a waterproof rubber sheet and achieves a first seal. As a result, after the terminal is soldered, even if water leaks into the waterproof rubber sheet during epoxy resin molding, it will not affect the stator coil.

[0032] Furthermore, in this invention, the protective mesh for the fan housing can be easily assembled by pressing the connecting ring of the protective mesh into the connecting hole of the fan housing and fastening the anti-vibration connector by tightening the connecting ring and the connecting hole. As a result, customers using cooling fans can also save the step of separately assembling the protective mesh onto the fan housing.

[0033] In general motors with protective nets, the protective net can be sold separately or assembled onto the cooling fan using bolts. However, in small fan motors, it is difficult for customers to determine the location of the fastening holes. In this invention, when the retaining ring of the protective net is pressed into the retaining groove of the fan housing and fastened using a vibration-damping fastener, the structure, which can be assembled using the retaining holes of the vibration-damping fastener that can be fastened to the customer's main body, is space-efficient. Attached Figure Description

[0034] Figure 1 A perspective view of a cooling fan according to an embodiment of the present invention.

[0035] Figure 2 for Figure 1 The image shows a top view of the cooling fan.

[0036] Figure 3 for Figure 1 The image shows a bottom view of the cooling fan.

[0037] Figure 4 for Figure 2 Sectional view along line AA in the diagram.

[0038] Figure 5 for Figure 2 BB line section view.

[0039] Figure 6 for Figure 2 The CC line section view.

[0040] Figure 7 This is a partially exploded perspective view of a cooling fan according to an embodiment of the present invention.

[0041] Figure 8 This is a fully exploded perspective view of a cooling fan according to an embodiment of the present invention.

[0042] Figures 9a to 9c An assembly process diagram of a printed circuit board of a cooling fan according to an embodiment of the present application. DETAILED DESCRIPTION

[0043] Hereinafter, preferred embodiments of the present application will be described with reference to the accompanying drawings.

[0044] In this process, the size or shape of the structural elements shown in the drawings can be exaggerated for the sake of clarity and convenience in explanation. Also, terms specifically defined in consideration of the structure and operation of the present application can be changed according to the intention of the user or the custom, and the definition of such terms should be based on the overall content of the specification.

[0045] The cooling fan of the present application is an axial fan that takes in outside air from an air inlet on one side of a fan housing and discharges the air to an air outlet on the other side in the axial direction, and can be used to prevent various electronic components such as microprocessors installed in electronic devices such as computers, light emitting diode illuminations, or electrical components of automobiles from overheating.

[0046] In this case, the cooling fan can be used by being built in the inside of the housing of the electronic device, or can be used in a state exposed to the outside environment such as rain, wind, or snow, and in particular, the motor driving circuit built in the inside of the fan housing of the cooling fan can be easily affected by waterproofing during the rainy season or heavy snowfall. The cooling fan of the present application can also structurally solve the waterproofing problem of the motor driving circuit in such an environment.

[0047] The accompanying drawings, Figure 1 is a perspective view of a cooling fan according to an embodiment of the present application, Figure 2 is Figure 1 is a plan view of the cooling fan shown, Figure 3 is Figure 1 is a bottom view of the cooling fan shown, Figure 4 is Figure 2 is a cross-sectional view taken along line A-A in FIG. 1, Figure 5 is Figure 2 is a cross-sectional view taken along line B-B in FIG. 1, Figure 6 is Figure 2 is a cross-sectional view taken along line C-C in FIG. 1.

[0048] Also, Figure 7 is a partially exploded perspective view of a cooling fan according to an embodiment of the present application, Figure 8 is a fully exploded perspective view of a cooling fan according to an embodiment of the present application.

[0049] First, as Figures 1 to 8As shown, the cooling fan 100 according to an embodiment of the present application includes a fan housing 10 having an air discharge port 14b formed in a front surface thereof to discharge air and an air inflow port 14a formed in a rear surface thereof to allow air to flow in; a rotating shaft 60 rotatably supported by the fan housing 10 at a lower portion thereof; a rotor 30 fixed to an upper portion of the rotating shaft 60; a stator 40 disposed at an upper portion of a printed circuit board housing 15 to be described later, and arranged at a predetermined interval from the rotor 30; an impeller 20 formed integrally with the rotor 30 at an outer circumferential portion of the rotor 30 to rotate together with the rotor 30; and a printed circuit board 50 arranged at a lower side of the stator 40, and having various circuit components for controlling a motor driving circuit of the cooling fan mounted therein to supply a motor driving signal to the stator 40.

[0050] The fan housing 10 is connected between the printed circuit board housing 15 in a semicircular shape and the cylindrical portion 11 by a plurality of bridge portions 16, 16a with the air inflow port 13a formed in a rear surface of the cylindrical portion 11, and has the air discharge port 14b formed in a front surface thereof, and a protective net 70 having a plurality of small holes 73 combined with the front surface of the air discharge port 14b to protect a user and prevent foreign substances from flowing in.

[0051] The fan housing 10 opens a front surface and a rear surface of the cylindrical portion 11 to allow air to pass therethrough, and is connected to the printed circuit board housing 15 for housing the printed circuit board 50 having various circuit components of the motor driving circuit mounted therein by a plurality of bridge portions 16, 16a at a center of the rear surface.

[0052] The printed circuit board housing 15 includes a disc portion 15a having the stator 40 disposed at an upper portion thereof; a circular wall 15b extending from an outer circumferential portion of the disc portion 15a to form a circular housing groove in an inner portion thereof; and a plurality of bridge portions 16, 16a connected between the circular wall 15b and the fan housing 10.

[0053] In this case, one of the plurality of bridge portions 16, 16a includes a plate-shaped bridge portion 16a having a housing groove structure to house an output terminal 51 connected to the printed circuit board 50 and having a strength capable of supporting a weight of the stator 40 and the rotor 30.

[0054] With respect to the printed circuit board housing 15, lower end portions of three pin-shaped terminals 52 extending from the stator 40 are soldered and fixed to the printed circuit board 50 arranged in the printed circuit board housing 15 after passing through the disc portion 15a of the printed circuit board housing 15, and then, epoxy resin molding is performed with respect to the printed circuit board housing 15 to thereby achieve sealing with respect to the printed circuit board 50.

[0055] After that, the cover part 55 is assembled at the lower part of the printed circuit board housing box 15. A plurality of guides 15e for housing the protective tape of the output terminal 51 at the bottom surface are protrudedly formed at the plate-shaped bridge part 16a of the printed circuit board housing box 15, and the cover part 55 assembled thereon is fixed to the printed circuit board housing box 15 and the plate-shaped bridge part 16a by a snap-fit coupling.

[0056] Also, a bearing housing 61 supporting the rotating shaft 60 in a rotatable manner and having the stator 40 fixed thereto is assembled at the lower end of the printed circuit board housing box 15. In this case, in order to increase the area in contact with the lower end of the bearing housing 61, a first extension part 15d is formed at the through hole formed at the center of the disc part 15a of the printed circuit board housing box 15 along the lower end of the bearing housing 61, and in order to increase the area in contact with the lower end of the bearing housing 61, a second extension part 55a is formed at the through hole formed at the center of the cover part 55 coupled to the bottom surface of the printed circuit board housing box 15. As a result, the lower end of the bearing housing 61 is supported in contact with the first extension part 15d and the second extension part 55a with a wide area, and stable support can be achieved.

[0057] The printed circuit board 50 is disposed inside the printed circuit board housing box 15, is in the form of a disc with the center opened and inserted to the outer surface of the bearing housing 61, and has the output terminal 51 connected to one side thereof for electrical connection with the body of the cooling fan 100.

[0058] Various circuit parts of a motor driving circuit for controlling the cooling fan are mounted at the printed circuit board 50, the coil 43 of the stator 40 is electrically connected to the motor driving circuit through the three pin-shaped terminals 52, and a hole sensor (not shown) for generating a rotational position signal of the rotor 30 is mounted.

[0059] As described below, in the stator 40, the three pin-shaped terminals 52 are inserted through the upper and lower insulators 42a and 42b and are fixed by welding at the lower end of the pin-shaped terminals 52 after passing through the disc part 15a of the printed circuit board housing box 15 and being assembled in a press-fit manner to the printed circuit board 50 disposed in the printed circuit board housing box 15, and stable physical support is achieved between the stator 40 and the printed circuit board housing box 15.

[0060] The bearing housing 61 is formed of a metal material and is in the form of a cylinder at the center of the fan housing 10, and the stator 40 is inserted and fixed to the outer surface thereof. Also, the upper and lower bearings 62a and 62b are provided at the upper and lower parts of the inner surface of the bearing housing 61, and the rotating shaft 60 is supported in a rotatable manner by the upper and lower bearings 62a and 62b.

[0061] The stator 40 includes a stator core 41 fixed to the outer circumferential surface of the bearing housing 61, upper and lower insulators 42a and 42b coupled to the upper and lower portions of the stator core 41 and surrounding the stator core 41, and a coil 43 wound around the upper and lower insulators 42a and 42b and supplied with a motor driving signal.

[0062] In the stator core 41, a plurality of teeth extend outward from the annular yoke.

[0063] The rotor 30 includes a magnet 31 disposed on the outer circumferential surface of the stator 40 with a predetermined gap therebetween and having N and S poles alternately arranged, a back yoke 32 disposed on the outer circumferential surface of the magnet 31, and a rotor support 33 fixed to the magnet 31 and the back yoke 32 and integrated with the impeller 20.

[0064] The rotor support 33 includes a disc portion 33a connected to the rotating shaft 60 at the center and having a disc shape, and a cylindrical portion 33b vertically extending from the edge of the disc portion 33a and having the magnet 31 and the back yoke 32 fixed to the inner surface thereof and the impeller 20 formed on the outer surface thereof.

[0065] The impeller 20 includes a plurality of blades 22 formed in a radial direction on the cylindrical portion 33b of the rotor support 33 and integrated with the rotor support 33. That is, the blades 22 of the impeller 20 are integrated with the rotor support 33 by insert molding in a state where the magnet 31, the back yoke 32, and the rotating shaft 60 are disposed in a mold, and the rotating shaft 60, the magnet 31, and the back yoke 32 are fixed to the rotor support 33 by the insert molding.

[0066] In the present application, three pin terminals 52 are used to connect the coil 43 of the stator 40 to the printed circuit board 50 disposed in the printed circuit board housing 15. That is, the fan motor 80 is constructed in a single phase motor mode suitable for a small motor, and thus one coil 43 is wound around the stator core 42. Accordingly, the connection of the coil 43 of the stator 40 to the printed circuit board 50 is achieved using three pin terminals 52 for the start terminal, the end terminal, and the ground terminal of the one coil 43.

[0067] The stator 40 is disposed on the upper portion of the printed circuit board housing 15, and a rubber plate 53 for waterproofing is interposed between the stator 40 and the printed circuit board housing 15. Accordingly, the three pin terminals 52 extending from the stator 40 pass through the rubber plate 53 for waterproofing, are inserted through the pin insertion holes of the printed circuit board housing 15, and extend into the interior of the printed circuit board housing 15 to be connected to the printed circuit board 50. In this case, the three pin terminals 52 are tightly attached to the rubber plate 53 for waterproofing by the elasticity of the rubber plate 53, and thus a sealed state can be maintained.

[0068] Therefore, when the printed circuit board housing 15 is molded with epoxy resin, even if the three pin terminals 52 extending from the stator 40 extend into the interior of the printed circuit board housing 15 through the pin insertion holes of the printed circuit board housing 15, the waterproof rubber sheet 53 can prevent the epoxy resin from leaking through the pin insertion holes.

[0069] The following is for reference Figures 9a to 9c This describes the printed circuit board assembly process of a cooling fan according to an embodiment of the present invention.

[0070] First, for the stator 40, the stator is completed by assembling an upper insulator 42a and a lower insulator 42b on the upper and lower parts of the stator core 42, and winding a coil 43 around the outer periphery of the upper insulator 42a and the lower insulator 42b.

[0071] Subsequently, after the three pin terminals 52 pass through the upper insulator 42a and the lower insulator 42b and are pressed into the assembly, one end of the coil of the coil 43, including the start terminal, the end terminal and the ground terminal, is welded and fixed to the upper end of the pin terminals 52.

[0072] Next, as Figure 9a As shown, by assembling the assembled stator 40 onto the upper part of the disc portion 15a of the printed circuit board housing 15, the lower end of the pin terminal 52 is assembled so that it passes through the waterproof rubber plate 53 and the upper part of the printed circuit board housing 15, and then faces the interior of the printed circuit board housing 15.

[0073] In this case, multiple partitions 15c are formed protruding from the outer side of the bottom surface of the receiving slot of the printed circuit board receiving box 15, so that when the printed circuit board 50 is assembled in the receiving slot, space can be ensured between the printed circuit board 50 and the bottom surface of the receiving slot.

[0074] After that, as Figure 9b As shown, if the printed circuit board 50 is assembled with the printed circuit board housing 15 reversed and the lower end of the pin-shaped terminal 52 passes through the pin insertion hole of the printed circuit board 50 and protrudes upward, then as... Figure 9c As shown, the protruding pin-shaped terminal 52 is electrically and physically fixed to the printed circuit pattern of the printed circuit board 50 by solder balls.

[0075] After the aforementioned terminal soldering, epoxy resin molding is performed on the printed circuit board housing 15 to complete a perfect waterproof structure for the printed circuit board 50. Then, by assembling the cover 55 on the lower side of the printed circuit board housing 15, the connection and assembly between the coil 43 and the printed circuit board 50 is completed.

[0076] In this case, if one end of the coil 43 is wound around the lower end of the pin terminal 52, inserted into the printed circuit board insertion hole, and soldered, the soldered surface is not always constant, so when the epoxy resin is applied to the printed circuit board surface, water can leak to the waterproof rubber plate.

[0077] As described above, in the present application, when the coil 43 is soldered and fixed to the upper end of the pin terminal 52, and the lower end of the pin terminal 52 is assembled to the printed circuit board 50, the lower end of the pin terminal 52 passes through the waterproof rubber plate 53 and is first sealed, and in this state, the lower end is assembled to the printed circuit board 50 located inside the partition of the printed circuit board housing 15. As a result, when the epoxy resin is molded after the pin terminal 52 is soldered, even if water leaks to the waterproof rubber plate 53, it does not affect the coil 43 of the stator 40.

[0078] As described above, in the present application, a sealing structure is adopted in which the coil end of the stator 40 and the printed circuit board 50 are separated by providing the printed circuit board housing 15 in which the printed circuit board 50 is assembled to the outer cover 10.

[0079] Also, in the cooling fan 100 of the present application, a protective net 70 having a plurality of small holes 73 formed in the upper side is provided on the upper side of the impeller 20 to safely partially prevent foreign substances from penetrating into the air discharge port.

[0080] In the protective net 70, a plurality of coupling rings 71, for example, 4 coupling rings 71, extend from the side of the outermost concentric circle 70a among the plurality of concentric circles 70a-70c in the lower side direction, and have a height difference structure in which the outer diameter of the outer peripheral portion gradually decreases toward the lower end. Each coupling ring 71 has a shape in which one side of a ring is cut and a gap 71a is formed, and the anti-vibration coupling member 75 can be coupled to the coupling ring 71 through the gap 71a.

[0081] The anti-vibration coupling member 75 is coupled to the inner side of the coupling ring 71, has a structure in which flanges are formed at both end portions, the lower end portion protrudes from the coupling ring 71 and extends, and a through hole 76 is formed at the center portion.

[0082] The above-described fan outer cover 10 is formed with four extension portions 12 in a square shape formed on the outer periphery of the cylindrical portion 11, and a plurality of coupling holes 13, for example, four coupling holes 13, are formed at the four corners of the square shape to be coupled to the protective net 70.

[0083] The above-described coupling hole 13 can have a height difference structure in which the inner diameter gradually decreases from the upper portion toward the lower portion, so as to correspond to the outer peripheral height difference structure of the coupling ring 71, and the above-described four extension portions 12 are formed with both end portions not connected to each other but terminated at intervals outside the coupling hole 13 and formed with a gap 12a into which the anti-vibration coupling member 75 is inserted and coupled.

[0084] The protective net 70 includes a plurality of concentric circular portions 70a-70c and a plurality of radial connecting portions 72a, 72b radially arranged in a direction orthogonal to the plurality of concentric circular portions 70a-70c, and has a plurality of small holes 73 formed by the plurality of concentric circular portions 70a-70c and the radial connecting portions 72a, 72b.

[0085] The assembly of the protective net 70 of the fan housing 10 can be easily achieved without additional screwing, i.e., after the coupling ring 71 of the protective net 70 is press-fitted into the coupling hole 13 of the fan housing 10, the anti-vibration coupling member 75 is press-fitted through the slit 12a of the coupling hole 13 and the slit 71a of the coupling ring 71.

[0086] The anti-vibration coupling member 75 is formed of a rubber material, and even if the through hole 76 is fixed to the body in which the cooling fan 100 is installed using a fixing bolt or the like, the vibration occurring due to the rotation of the impeller 20 when the cooling fan 100 is driven is prevented from being transmitted to the body in which the cooling fan 100 is installed.

[0087] As described above, in the present application, when the protective net 70 is assembled to the housing 10, after the coupling ring 71 of the protective net 70 is press-fitted into the coupling hole 13 of the fan housing 10, the anti-vibration coupling member 75 can be press-fitted through the slit 12a of the coupling hole 13 and the slit 71a of the coupling ring 71, and as a result, for a customer using the cooling fan 100, a separate process of assembling the protective net 70 to the housing 10 can be omitted.

[0088] A general motor having a protective net sells the protective net alone, or assembles the protective net to a cooling fan using a bolt, and in a small fan motor, it is difficult for a customer to grasp the position of a hole for fastening.

[0089] In the present application, if the fastening is performed using the anti-vibration coupling member 75 after the coupling ring 71 of the protective net 70 is press-fitted into the coupling hole 13 of the fan housing 10, as a structure that can be assembled using a hole capable of being fastened to a body of a customer, it is easy to use space.

[0090] The present application has been illustrated and described above with reference to specific preferred embodiments, but the present application is not limited to the above-described embodiments, and various changes and modifications can be made by those skilled in the art without departing from the spirit of the present application.

[0091] Industrial Applicability

[0092] The present application can be applied to a cooling fan in which a printed circuit board housing is provided in a fan housing, a printed circuit board on which a motor driving circuit is mounted is assembled, and a complete waterproof structure is obtained by separating a coil end from the printed circuit board.

Claims

1. A cooling fan, characterized in that, include: The fan casing has an air outlet on the front surface for exhausting air and an air inlet on the back surface for allowing air to flow in. The rotating shaft is supported at the bottom by the fan casing in a rotatable manner. The rotor is fixed to the upper part of the aforementioned rotating shaft; The stator is disposed inside the rotor at a specified interval from the rotor. The impeller is connected to the outer periphery of the rotor and rotates with it; A protective mesh is installed on the upper side of the impeller. The upper side of the mesh has multiple holes to prevent foreign objects from seeping through the air outlet on the upper side of the impeller. The aforementioned protective net also includes four connecting rings, each in a ring shape. These four connecting rings extend downwards from the outermost concentric circle forming multiple holes in the protective net, creating four connecting holes on the fan casing that connect the four connecting rings. The aforementioned connecting ring has a height difference structure in which the outer diameter of the outer periphery gradually decreases towards the lower end, and the aforementioned connecting hole has a height difference structure in which the inner diameter gradually decreases from the upper part towards the lower part, so as to correspond to the height difference structure of the outer periphery of the connecting ring. The aforementioned connecting ring is pressed into the upper part of the connecting hole, and the anti-vibration connecting member located inside the aforementioned connecting ring is fastened by the aforementioned connecting ring and the aforementioned connecting hole to achieve the assembly of the aforementioned protective net.

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