Sleeve Bearing and Axial Type Fan Using the Same

Abstract

The present invention relates to a sleeve bearing that eliminates the insertion of a support seat by employing a sleeve bearing with a closed lower end to support a rotating shaft, and an axial-flow fan using the same. The fan according to the present invention comprises: a fan housing having a cylindrical inner circumference; a base connected from the rear surface of the fan housing through a plurality of bridges and having a bearing housing integrally formed with a protruding central portion; a sleeve bearing inserted into the bearing housing; a rotating shaft whose lower portion is rotatably supported by the sleeve bearing; a rotor fixed to the upper portion of the rotating shaft; a stator fixed on the base, having an inner circumference coupled to the outer circumference of the bearing housing and positioned with a certain gap from the rotor; and an impeller integrally formed on the outer circumference of the rotor and rotating together with it; wherein the sleeve bearing is characterized in that the bottom portion of the groove contacted by the lower portion of the rotating shaft is closed.

Description

Technology Field

[0001] The present invention relates to an axial flow fan, and more specifically, to a sleeve bearing and an axial flow fan using the same, which can simplify the manufacturing process, reduce manufacturing costs, and improve durability by employing a sleeve bearing with a closed lower end to support a rotating shaft, thereby eliminating the insertion of a support seat. Background Technology

[0002] Currently, to create a comfortable environment inside a vehicle, the vehicle's air conditioning system measures indoor temperature, humidity, and fine dust, then performs heating and cooling based on temperature and humidity data, and operates electrostatic precipitator filters based on fine dust data.

[0003] One method of checking indoor temperature and humidity is to use a motor equipped in an in-car sensor to draw in indoor air and create a forced airflow to measure temperature and humidity, thereby checking the environmental conditions inside the vehicle.

[0004] In addition, with the recent increase in interest regarding fine dust, indoor conditions are checked by measuring the concentration of fine dust. Fine dust measurement is also performed using a method that draws in indoor air using a motor equipped in the fine dust sensor.

[0005] In-Car sensors and fine dust sensors are also installed on the grille or instrument panel of a vehicle, and detect the temperature and concentration (or amount of fine dust) of the indoor air by drawing in indoor air using an aspirator method. In this case, the fine dust sensor can measure the amount of fine dust by irradiating the inhaled indoor air with a predetermined light and measuring the amount of light scattered by the fine dust in the air.

[0006] Conventional blower fans (i.e., aspiration motors) installed in the air passage to draw in indoor air of a vehicle are small and do not require precise and complex speed control, so single-phase motors using a single coil are used, which have a simple structure.

[0007] The above-mentioned blower fan is an axial-flow type fan that draws in external air from an air intake on one side of the housing and discharges it along the axial direction to an air outlet on the other side, and can be installed in the flow path of the housing. In addition, cooling fans used to prevent overheating of electronic components are also axial-flow type fans.

[0008] In conventional axial-flow fan motors, a brass bushing serving as a bearing housing is formed in the center by insert injection molding within a resin housing, and a sleeve bearing is inserted into the bushing to rotatably support the rotor's rotation axis.

[0009] Additionally, a support sheet is inserted into the lower part of the bearing housing to reduce rotational resistance of the rotating shaft, and the housing is impregnated with oil. In this case, as the temperature rises due to the rotation of the rotor, the air and oil inside the bearing housing expand in volume due to thermal expansion, causing the oil to rise along the rotating shaft and scatter. In this situation, if a metal bearing housing is press-fitted into a resin housing, the heat dissipation is poor, making it prone to oil scattering if the temperature rises significantly.

[0010] Furthermore, conventionally, when using a through-type sleeve bearing, a support seat is inserted into the lower part of the bearing housing to reduce rotational resistance of the rotating shaft extending below the sleeve bearing. However, during the manufacturing process, the support seat is often omitted and cannot be placed in a predetermined position, causing various problems, and there is also a problem of reduced durability due to wear of the support seat.

[0011] In addition, conventional aspiration motors have a problem in which the rotating shaft detaches due to lift force when the rotor (impeller) rotates, and to prevent this, a structure is adopted in which a slit washer is coupled to a groove formed at the bottom of the rotating shaft. However, in this case, when the rotating shaft rises due to lift force when the rotor (impeller) rotates, the slit washer comes into contact with the sleeve bearing, causing a problem of noise.

[0012] Furthermore, conventional fan motors can configure the rotor by attaching a magnet to the impeller using adhesive along with the back yoke, or by insert molding the magnet and back yoke during impeller injection.

[0013] The aforementioned insert molding type and bond assembly method result in increased unit costs and, due to the existence of assembly tolerances, cause problems that negatively affect balance; therefore, balance correction is performed by inserting balance correction chips or other weights.

[0014] In addition, conventional fan motors have a problem of reduced productivity because bonding and caulking operations on the contact surface between the stator and the bushing are essential to prevent the stator from detaching or rotating when assembling the stator to the bushing. Prior art literature

[0015] : Korean Published Patent Application No. 10-2019-0066898 The problem to be solved

[0016] Accordingly, the present invention is proposed to solve the problems of the aforementioned prior art, and its purpose is to provide a sleeve bearing and an axial-flow fan using the same, which can simplify the manufacturing process, reduce manufacturing costs, and improve durability by eliminating the insertion of a support seat through the adoption of a sleeve bearing with a closed lower end to support a rotating shaft.

[0017] Another objective of the present invention is to provide an axial-flow fan that prevents oil splashing without using a separate oil splashing prevention washer and simultaneously suppresses the detachment of the rotating shaft caused by lift by inserting a stopper washer so that the outer circumference is positioned between the bobbin extension and the stepped portion at the top of the bearing housing and the inner circumference is positioned close to the groove preventing detachment of the rotating shaft.

[0018] Another objective of the present invention is to provide an axial-flow fan that can simply prevent the stator from detaching and rotating by coupling a plurality of connecting protrusions extending from the bearing housing to the through holes of the stator when assembling the stator to the bearing housing, and then fixing the exposed tip portions by a high-frequency heat fusion method.

[0019] Another objective of the present invention is to provide an axial-flow fan that can omit the back yoke by using a plastic magnet to integrally form the entire impeller and the magnet portion, insert-molding only the shaft, and then magnetizing only the desired inner portion to form an N / S magnet. means of solving the problem

[0020] To achieve the above-mentioned purpose, a sleeve bearing according to one feature of the present invention is a sleeve bearing that rotatably supports a rotating shaft, comprising: a main body formed in the shape of a cylindrical rod and compressed into the inner circumference of a groove of a bearing housing; a middle section having an outer diameter smaller than that of the main body through an inclined section on the lower side of the main body; and a lower section extending from the lower side of the middle section; wherein a circular groove into which the rotating shaft is inserted is formed in the central part from the upper part of the main body to the middle section, and the bottom portion of the groove contacted by the lower section of the rotating shaft is closed.

[0021] The sleeve bearing according to the present invention may further include at least one slot forming an oil circulation path extending from the groove to the outside.

[0022] A fan according to one feature of the present invention comprises: a fan housing having a cylindrical inner circumference; a base connected from the rear surface of the fan housing through a plurality of bridges and having a bearing housing integrally formed with a protruding central portion; a sleeve bearing inserted into the bearing housing; a rotating shaft whose lower portion is rotatably supported by the sleeve bearing; a rotor fixed to the upper portion of the rotating shaft; a stator fixed on the base, having an inner circumference coupled to the outer circumference of the bearing housing and positioned with a certain gap from the rotor; and an impeller integrally formed on the outer circumference of the rotor and rotating together with it; wherein the sleeve bearing is characterized by having a structure in which the bottom portion of a groove contacted by the lower portion of the rotating shaft is closed.

[0023] A fan according to one feature of the present invention may further include a stopper washer in which the outer circumference is disposed on the stepped portion at the top of the bearing housing and the inner circumference is close to the anti-detachment groove of the rotation shaft.

[0024] In addition, the inner diameter of the through hole formed in the inner circumference of the stuffer washer can be set to be smaller than the outer diameter of the rotation shaft and larger than the outer diameter of the anti-detachment groove. Effects of the invention

[0025] As described above, in the present invention, by employing a sleeve bearing with a closed lower end to support the rotation axis, the insertion of a support seat is eliminated, thereby simplifying the manufacturing process, reducing manufacturing costs, and improving durability.

[0026] As a result, conventionally, a support seat is inserted into the lower part of the bearing housing to reduce rotational resistance of the rotating shaft by employing a through-type sleeve bearing. However, during the manufacturing process, the support seat is not inserted in a predetermined position, causing various problems, and there is also a problem of reduced durability due to wear of the support seat. In contrast, the present invention employs a sleeve bearing with a closed lower end and eliminates the insertion of the support seat, thereby simplifying the manufacturing process, reducing manufacturing costs, and resolving the problem of reduced durability caused by wear of the support seat.

[0027] In addition, in the present invention, by inserting a stopper washer in which the outer circumference is positioned between the bobbin extension and the stepped portion at the top of the bearing housing and the inner circumference is close to the groove preventing the rotation shaft from coming off, it is possible to prevent oil splashing without using a separate oil splashing prevention washer and at the same time suppress the rotation shaft from coming off due to lifting force. Furthermore, reliability can be increased by minimizing the open space between the bobbin and the sleeve bearing to prevent oil leakage as much as possible.

[0028] Conventionally, noise was generated by attaching a slit washer to the rotating shaft to prevent the rotating shaft from coming off, but in the present invention, the rotating shaft can be prevented from coming off without generating noise by not using a slit washer.

[0029] Furthermore, in the present invention, the back yoke can be omitted by using a plastic magnet to form the entire impeller and the magnet portion, insert-molding only the shaft, and then magnetizing only the desired inner portion to form an N / S magnet.

[0030] Ordinarily, magnets are classified into anisotropic and isotropic types. Plastic magnets can be polar anisotropic if the thickness of the magnet is 1.5t or more, so a back yoke is not required.

[0031] As a result, in the present invention, by using a plastic magnet, the back yoke is removed from the overall structure and the wall thickness of the general injection molded part surrounding the magnet and back yoke is reduced, so the magnet area can be maximized within the same size, thereby increasing the effective magnetic flux density and thus increasing the efficiency of the motor. Additionally, it is easy to manufacture and minimizes assembly tolerances, which creates favorable conditions for balance and is advantageous for reducing unit costs.

[0032] Furthermore, in the present invention, when assembling the stator to the bearing housing, the detachment and rotation of the stator can be simply prevented by coupling a plurality of connecting protrusions extending from the bearing housing to the through hole of the stator and then fixing the exposed tip portion by a high-frequency heat fusion method.

[0033] In other words, in the present invention, by integrally forming the bearing housing on the base, the bushing made of brass that serves as the bearing housing can be omitted. Furthermore, the problem of reduced productivity caused by bonding and caulking operations on the contact surfaces of the stator and the bushing when assembling the stator and the bushing in the conventional manner can be simply prevented by fixing the tip of the connecting projection extended from the bearing housing using a high-frequency heat fusion method, thereby preventing the stator from detaching and rotating. Brief explanation of the drawing

[0034] FIGS. 1a and FIGS. 1b are a perspective view and a bottom view, respectively, showing an axial flow fan according to a preferred embodiment of the present invention. FIG. 2 is an axial cross-sectional view of an axial flow fan according to a preferred embodiment of the present invention. FIG. 3 is a radial cross-sectional view of an axial flow fan according to a preferred embodiment of the present invention. FIG. 4 is an exploded perspective view of an axial flow fan according to a preferred embodiment of the present invention. FIG. 5 is an exploded perspective view of an axial flow fan by module according to a preferred embodiment of the present invention. FIG. 6 is a perspective view showing the state in which the stator in FIG. 5 is assembled to the bearing housing. FIG. 7 is an enlarged perspective view of a bobbin. FIGS. 8a to 8e are a perspective view in an upright state, a perspective view in a horizontal state, a top view, a bottom view, and a longitudinal cross-sectional view, respectively, of a sleeve bearing according to a preferred embodiment of the present invention. Specific details for implementing the invention

[0035] Hereinafter, a preferred embodiment according to the present invention will be described with reference to the attached drawings.

[0036] In this process, the size or shape of components depicted in the drawings may be exaggerated for clarity and convenience of explanation. Additionally, terms specifically defined in consideration of the configuration and operation of the present invention may vary depending on the intent or convention of the user or operator. Definitions of such terms should be based on the content throughout this specification.

[0037] The axial flow fan according to the present invention is a fan that draws in external air from an air intake on one side of a housing and discharges it along the axial direction to an air outlet on the other side, and can be used in various ways, such as a blower fan installed in a flow path for a housing for a fine dust sensor or a cooling fan used to prevent overheating of electronic components.

[0038] Figures 1a and 1b attached are a plan view and a perspective view, respectively, showing an axial flow fan according to a preferred embodiment of the present invention, and Figure 2 is a cross-sectional view showing an axial flow fan according to a preferred embodiment of the present invention.

[0039] First, an axial flow fan (100) according to one embodiment of the present invention, as shown in FIGS. 1a to 2, comprises a fan housing (10) having an air discharge port (14b) formed on the front surface for discharging air and an air inlet port (14a) formed on the back surface for introducing air; a base (11) integrally formed with a bearing housing (61) protruding from the central portion, which is connected to the back surface of the fan housing (10) through a plurality of bridges (16) and supports a sleeve bearing (62), a PCB (50), a stator (40), and an impeller (20); a sleeve bearing (62) inserted into the bearing housing (61); a rotating shaft (60) whose lower portion is rotatably supported by the sleeve bearing (62); a rotor (30) fixed to the upper portion of the rotating shaft (60); a stator (40) coupled and fixed to the outer periphery of the bearing housing (61) and arranged with a certain gap from the rotor (30); and the It includes an impeller (20) formed integrally on the outer circumference of the rotor (30) and rotating together with it, and a printed circuit board (PCB) (50) fixedly positioned between the upper side of the base (11) and the lower side of the stator (40) and on which various circuit components of a motor drive circuit for fan control are mounted to supply a motor drive signal to the stator (40).

[0040] The above fan housing (10) is open at the front and back so that air can pass through, as the base (11) is connected through a plurality of bridges (16) from the back.

[0041] Additionally, a plurality of guide protrusions (11a) are spaced apart and protrude from the outer periphery of the base (11) to guide a printed circuit board (PCB) (50) fixed to the upper part of the base (11).

[0042] Furthermore, the fan housing (10) has an inner circumference (10c) that is cylindrical and an outer circumference that is approximately rectangular. At four corners of the rectangle, through holes (10a) are formed that are necessary for fixing the fan (100) to the main body using fixing bolts or fixing screws, and at one corner, a guide projection (10b) is formed to guide and organize the harness (52) that is drawn out from the PCB (50).

[0043] The bearing housing (61) integrally formed on the base (11) is structured such that a circular groove (61a) is formed inside, and the sleeve bearing (62) is press-fitted into the groove (61a), and the lower end of the sleeve bearing (62), which has a closed lower end as described later, is positioned at the bottom of the groove (61a).

[0044] The groove (61a) of the bearing housing (61) is impregnated with oil to reduce the rotational resistance of the rotating shaft (60).

[0045] A second step portion (61c) is formed on the outer periphery of the bearing housing (61) in which the inner periphery of the stator (40) is press-fitted and fixed at an intermediate position, and a third step portion (61d) is formed on the lower side of the outer periphery in which the inner periphery of the PCB (50) is seated.

[0046] The PCB (50) is formed in the shape of a disc with an open center that is inserted into the outer surface of a bearing housing (61), and a harness (52) is connected to one side of the PCB (50) for electrical connection with a main body in which a fan (100) is used, and the front end of the harness (52) is drawn out to the outside and connected to an output connector (51).

[0047] The bearing housing (61) is formed to protrude in a cylindrical shape in the center of the base (11), and the inner circumference of the stator (40) is press-fitted and fixed to its outer surface.

[0048] As shown in FIGS. 4 and 5, the stator (40) comprises a stator core (45) in which the inner circumference is fixed to the outer circumference of a bearing housing (61), a bobbin (43) surrounding the coil winding area of ​​the stator core (45) and the back yoke (42), and a coil (44) wound in the coil winding area of ​​the bobbin (43) to which a motor driving signal is applied.

[0049] The bobbin (43) has four outer guide protrusions (430a-430d) protruding outward to define four coil winding regions corresponding to four teeth (41), and the inner guide (43e) corresponding to the outer guide protrusions (430a-430d) protrudes in a ring shape.

[0050] The above stator core (45) has a plurality of teeth (41) formed in a 'T' shape that extend radially on the outer side of the annular yoke (42). In this case, a single circular projection (42a) with a through hole (42b) formed therein may protrude on the outer side of the annular back yoke (42).

[0051] In the through hole (42b) of the above circular projection (42a), as described later, one of a plurality of, for example, four connecting projections (64a-64d) protruding from the bearing housing (61) to fix the stator (40) after assembling the stator (40) to the outer circumference of the bearing housing (61) can pass through.

[0052] Additionally, three of the four connecting protrusions (64a-64d) are coupled to through holes (42c) formed in three circular protrusions (43a-43c) protruding from the bobbin (43) surrounding the back yoke (42), so that the tip portion protrudes to the upper part of the bobbin (43).

[0053] In this case, the circular protrusions (42a) and (43a-43c) are all placed between the teeth and serve to support the four connecting protrusions (64a-64d).

[0054] Furthermore, the bobbin extension (43f) formed on the upper part of the bobbin (43) is extended to the center, and a through hole (43h) is formed in the center through which the rotation axis (60) of the rotor (30) passes.

[0055] A first stepped portion (61b) is formed in the upper inner portion of the bearing housing (61), and a circular groove space with a trench-shaped cross section is formed between the first stepped portion (61b) and the bobbin extension portion (43f).

[0056] In the above circular groove space, an outer periphery is positioned and a stopper washer (63) is inserted so that the inner periphery is close to the anti-detachment groove (60b) of the rotation shaft (60). In this case, the stopper washer (63) may be a C-ring or an O-ring.

[0057] In this case, the stopper washer (63) is movably positioned in the circular groove space and does not remain in a fixed state. When the stopper washer (63) of the movable C-ring structure is displaceably positioned in the circular groove space in this manner, even if a vertical load is applied to the stopper washer (63) when the impeller (20) rises or falls, the stopper washer (63) of the C-ring structure can be restored to its original position by tension after its outer edge spreads outward in the radial direction.

[0058] The above stopper washer (63) can prevent the rotation shaft (60) from coming off due to lifting force as its inner portion is positioned close to the anti-detachment groove (60b) of the rotation shaft (60).

[0059] Additionally, the stopper washer (63) is positioned so that its outer circumference is located at the first stepped portion (61b) of the upper inner circumference of the bearing housing (61), and the inner circumference is set to have an inner circumference and an outer circumference diameter so as to be close to the anti-detachment groove (60b) of the rotation shaft (60). As a result, even if the oil rises along the rotation shaft (60) due to volume expansion of the air and oil inside the bearing housing (61) caused by the temperature rise due to the rotation of the rotor (30), it can be induced to return to the inside of the bearing housing (61) while preventing the oil from scattering by coming into contact with the lower surface of the stopper washer (63).

[0060] As a result, in the present invention, the stopper washer (63) not only prevents the rotation shaft (60) from coming off, but also prevents oil splashing without using a separate oil splash prevention washer.

[0061] Meanwhile, the rotor (30) includes a magnet (31) that is positioned at a certain gap on the outer surface of the stator (40), formed in a cylindrical shape, and has a structure in which N and S poles are alternately divided and magnetized, and a rotor support (33) formed integrally with the magnet (31) and the impeller (20).

[0062] In the present invention, when forming the entire impeller (20) and the magnet (31) portion of the rotor (30) as a single unit using a plastic magnet, the rotor (30) and the impeller (20) can be formed as a single unit by insert molding only the rotation shaft (60) in the center and injection molding, and then forming N-pole and S-pole magnets (31) by splitting and magnetizing only the desired inner portion.

[0063] Ordinarily, magnets are divided into anisotropic and isotropic types, but plastic magnets can be manufactured as polar anisotropic magnets that do not require a rotor back yoke if the magnet thickness is 1.5t or more.

[0064] In the present invention, the rotor (30) and the impeller (20) are integrally formed by injection molding using a plastic magnet, and when the magnet (31) portion of the rotor (30) is divided and magnetized, the thickness of the magnet (31) is set to be 2.0t or more, thereby manufacturing an extremely anisotropic magnet that does not require a back yoke.

[0065] The above plastic magnet is a polymer bonded magnet, and uses a material produced by mixing a polymer resin with iron oxide (SrO6Fe2O3) mixed with strontium, barium, and ferrite as the main raw material. By using this, the impeller and rotor are injection molded as a single unit, and then magnetizing only the inner part to form an N / S magnet, it is possible to form the interface and omit the back yoke.

[0066] As polymer resins, thermosetting resins such as rubber, phenol, and epoxy resins, and thermoplastic resins such as PVC, chlorinated polyethylene, PP, EVA, and nylon can be used.

[0067] In the present invention, the plastic magnet may be, for example, a mixture of nylon and iron oxide or samarium powder.

[0068] Conventionally, when manufacturing a rotor-integrated impeller, the impeller and rotor support are formed using only nylon resin, and a separately prepared magnet and back yoke are manufactured by insert molding.

[0069] In this regard, when manufacturing a rotor-integrated impeller that can omit the back yoke by using a plastic magnet as in the present invention, it is possible to manufacture it at a lower cost than in the conventional method of manufacturing a rotor-integrated impeller by insert molding a separately prepared magnet and back yoke.

[0070] Therefore, in the present invention, by using a plastic magnet, the back yoke is removed from the overall structure and the wall thickness of the general injection molded part surrounding the magnet and back yoke is also reduced, so the magnet area can be maximized within the same size, thereby increasing the effective magnetic flux density and increasing the efficiency of the motor. Additionally, manufacturing is easy, assembly tolerances are minimized, which creates favorable conditions for balance, and it is advantageous for reducing unit costs.

[0071] The rotor support (33) is manufactured using a plastic magnet together with an impeller (20) and includes a disc portion (33a) formed in the shape of a disc with a rotating shaft (60) connected in the center, and a cylindrical portion (33b) that extends vertically from the edge of the disc portion (33a), has a magnet (31) disposed on its inner surface, and has an impeller (20) formed on its outer surface.

[0072] In the center of the disc portion (33a) of the rotor support (33), a shaft support portion (34) is vertically extended to support the rotation axis (60).

[0073] The impeller (20) is formed integrally with the rotor support (33) and includes a plurality of blades (22) formed radially on the cylindrical portion (33b) of the rotor support (33). That is, insert injection is performed with the rotation axis (60) placed in the mold so that the blades (22) of the impeller (20) and the rotor support (33) are formed integrally, and the rotation axis (60) is fixed to the rotor support (33) by insert molding.

[0074] Meanwhile, the rotor (30) of the present invention may include a magnet (31) which is formed in a cylindrical shape and arranged with a certain gap on the outer surface of the stator (40) and has a structure in which N poles and S poles are alternately arranged or N poles and S poles are alternately divided and magnetized, a back yoke arranged on the outer surface of the magnet (31), and a rotor support (33) in which the magnet (31) and the back yoke are fixed and the impeller (20) is integrally formed.

[0075] The rotating shaft (60), which is integrally formed in the center of the rotor support (33) by an insert injection method, has an annular first groove (60a) and an annular anti-detachment groove (60b) formed therein.

[0076] The first groove (60a) is intended to prevent separation while increasing the mutual coupling area with the rotor support (33), and the anti-detachment groove (60b) is intended to prevent the rotation shaft (60) from detaching from the sleeve bearing (62) when the lower end of the rotation shaft (60) passes through the through hole (43h) of the bobbin (43) and then presses through the inner circumference through hole of the stopper washer (63) to be coupled to the sleeve bearing (62).

[0077] In this case, when a vertical load is applied, the stopper washer (63) may use a C-ring structure in which the outer edge spreads out in the radial direction and then returns to its original position by tension.

[0078] On the upper part of the sleeve bearing (62), an inclined portion (62f) is formed to guide the lower end of the rotating shaft (60) to enter more easily when it is inserted into the through hole (62e).

[0079] In the present invention, it is preferable that the inner diameter of the stopper washer (63) be smaller than the outer diameter of the rotation shaft (60) and larger than the outer diameter of the anti-detachment groove (60b).

[0080] As a result, when the lower end of the rotating shaft (60) passes through the through hole of the stopper washer (63) by a press-fit method and is once coupled to the sleeve bearing (62), even if a lifting force is generated that causes the impeller (20) and the rotating shaft (60) to rise as the rotor (30) rotates, the lower end of the anti-detachment groove (60b) catches on the edge of the through hole, thereby preventing the rotating shaft (60) from detaching from the sleeve bearing (62).

[0081] Additionally, as shown in FIG. 2, the stopper washer (63) has only a small through hole formed in the center through which the rotation axis (60) of the rotor (30) barely passes, and the bottom surface of the stopper washer (63) is in contact with the upper part of the bearing housing (61).

[0082] As a result, in the present invention, the inner circumference of the stopper washer (63) is formed to be close to the anti-detachment groove (60b) of the rotating shaft (60), so that even if the air and oil inside the bearing housing (61) rise along the rotating shaft (60) due to thermal expansion as the rotor (30) rotates, they are caught on the bottom surface of the stopper washer (63) and return to the inside of the bearing housing (61). Therefore, in the present invention, oil splashing can be prevented without using a separate oil splashing prevention washer, thereby improving the efficiency of man-hours.

[0083] Furthermore, as illustrated in FIGS. 3 to 6, when the stator (40) is assembled to the bearing housing (61), the four connecting protrusions (64a-64d) protruding from the bearing housing (61) are coupled to a through hole (43g) formed in the bobbin extension (43f) of the bobbin (43) and a through hole (42b) of the circular protrusion (42a), so that the tip portion protrudes to the upper part of the bobbin (43). Accordingly, in the present invention, if the four connecting protrusions (64a-64d) protruding to the upper part of the bobbin (43) are fused using a high-frequency heat fusion method, the connection between the bearing housing (61) and the bobbin (43) can be easily formed, and as a result, the detachment and rotation of the stator (40) can be prevented.

[0084] delete

[0085] Meanwhile, in the present invention, as shown in FIGS. 2 and FIGS. 8a to 8e, by employing a sleeve bearing (62) with a closed lower end to support a rotating shaft (60), the insertion of a support seat can be eliminated, thereby simplifying the manufacturing process, reducing manufacturing costs, and improving durability.

[0086] Referring to FIGS. 8a to 8e, the sleeve bearing (62) according to the present invention comprises a main body (62a) located at the upper side, a middle section (62c) having an outer diameter smaller than that of the main body (62a) through an inclined section (62b) at the lower side of the main body (62a), and a lower section (62d) extended at the lower side of the middle section (62c). In this case, the main body (62a) is formed to have a longer length than the middle section (62c) and the lower section (62d).

[0087] The outer circumference of the main body (62a) of the sleeve bearing (62) is fixed as it is compressed and coupled to the inner circumference of the groove (61a) of the bearing housing (61), and the middle part (62c) and the lower part (62d) preferably have an outer diameter smaller than that of the main body (62a) so that they can be easily inserted into the groove (61a) of the bearing housing (61).

[0088] The sleeve bearing (62) is formed in the shape of a cylindrical rod overall, and has a structure in which a circular groove (62e) is formed in the central part facing downward from the main body (62a) to the middle part (62c) and the lower part (62d) is closed.

[0089] The lower portion (62d) has a structure in which the bottom portion of the groove (62e) contacting the lower portion of the rotating shaft (60) is closed, and in the illustrated embodiment, a slot (62j) is formed to form a plurality, for example, four oil circulation paths extending from the groove (62e) to the outside, and may be connected to the groove (62e). In this case, it is also possible for the lower portion (62d) to have a structure in which the slot (62j) extending from the groove (62e) to the outside is not formed and is closed.

[0090] Additionally, an inclined portion (62f) may be formed between the upper surface (62g) and the central groove (62e) of the sleeve bearing (62) to facilitate the insertion of the rotating shaft (60) into the groove (62e).

[0091] Furthermore, a plurality of grooves (62h) forming an oil circulation path are formed radially on the upper surface (62g) of the sleeve bearing (62), and a plurality of grooves (62i) forming an oil circulation path are formed longitudinally on the outer periphery of the main body (62a). These plurality of grooves (62h, 62i) form an oil circulation path in which, as the temperature rises due to the rotation of the rotor (30) and the rotating shaft (60), the air and oil inside the bearing housing (61) expand in volume due to thermal expansion, causing the oil to rise along the rotating shaft (60), catch on the bottom surface of the stopper washer (63), and return to the groove (62e) inside the bearing housing (61).

[0092] As a result, conventionally, a support seat is inserted into the lower part of the bearing housing to reduce rotational resistance of the rotating shaft by employing a through-type sleeve bearing; however, during the manufacturing process, the support seat is often omitted or fails to be placed in a predetermined position, causing various problems, and a decrease in durability due to wear of the support seat has also occurred.

[0093] However, in the present invention, by adopting a sleeve bearing (62) having a structure in which the bottom portion of the groove (62e) contacted by the lower end of the rotating shaft (60) is closed, the insertion of the support seat is eliminated, thereby simplifying the manufacturing process and reducing the manufacturing cost, and there is an advantage in that the problem of reduced durability due to wear of the support seat is also resolved.

[0094] The sleeve bearing (62) according to the present invention can be manufactured from compressed powder metal, such as bronze or copper, for example.

[0095] In the present invention, three pin terminals (53) are used to connect the coil (44) of the stator (40) and the PCB (50). That is, since the fan motor in the present invention is configured as a single-phase motor suitable for small motors, one coil (44) is wound on the stator core (45). Accordingly, three pin terminals (53) are used to include the start terminal, end terminal, and ground terminal (GND) of one coil (44) for the connection between the coil (44) of the stator (40) and the PCB (50). The ground terminal (GND) can be used to implement EMC or EMI.

[0096] In the description of the embodiments of the present invention, a fan motor (80) with a 4-slot-4-magnet structure is disclosed using a single-phase motor method, but it can be configured with a 3-phase BLDC motor.

[0097] Various circuit components of a motor drive circuit that controls a fan are mounted on the PCB (50), and the coil (44) of the stator (40) is electrically connected to the motor drive circuit through three pin terminals (53), and a Hall sensor (not shown) that generates a rotational position signal of the rotor (30) is also mounted.

[0098] In addition, as described below, the stator (40) has three pin terminals (53) that are press-fitted through the bobbin (43) and the lower end of the pin terminals (53) is soldered and fixed to the PCB (50), thereby providing stable physical support between the stator (40) and the PCB (50).

[0099] The assembly process of a fan according to one embodiment of the present invention is described below.

[0100] First, the stator (40) is integrally formed by insert injection using resin, wherein a bobbin (43) with a bobbin extension (43f) is formed on the upper part while the coil winding area on the outer circumference of the stator core (45) is covered with an insulator. The stator (40) is completed by winding a coil (44) on the outer circumference of the coil winding area.

[0101] After that, three pin terminals (53) are press-fitted through the bobbin (43), and then one of the coil ends of the start terminal, end terminal, and ground terminal of the coil (44) is fixed by soldering to the top of the pin terminal (53).

[0102] Next, the stator (40) is assembled on the upper part of the PCB (50) so that the lower end of the pin terminal (53) passes through the pin insertion hole of the PCB (50) and protrudes downward, and the protruding pin terminal (53) and the printed circuit pattern of the PCB (50) are electrically and physically fixed by soldering.

[0103] Meanwhile, a fan housing (10) is prepared in which a base (11) is connected to the back surface through a plurality of bridges (16) and a bearing housing (61) protrudes from the center of the base (11) to form a single unit.

[0104] Next, a sleeve bearing (62) is assembled inside the bearing housing (61).

[0105] After that, a stator (40) with a PCB (50) mounted on its lower part is attached to the outer circumference of a bearing housing (61). In this case, the four connecting protrusions (64a-64d) protruding from the bearing housing (61) have their leading ends protruding to the upper part of the bobbin (43) through a through hole (43g) formed in the bobbin extension (43f) of the bobbin (43).

[0106] Next, the connection between the bearing housing (61) and the bobbin (43) is secured by heat-fusing the four connecting protrusions (64a-64d) protruding from the upper part of the bobbin (43) to the upper part of the bobbin (43) using a high-frequency heat-fusing method. As a result, the stator (40) can be prevented from detaching from or rotating from the bearing housing (61).

[0107] Finally, using a plastic magnet, the entire impeller (20) and the magnet (31) portion are integrally formed, and only the shaft (60) is insert-molded and injection-molded, after which only the desired inner portion is magnetized to selectively form an N / S magnet (31).

[0108] Next, the lower end of the rotating shaft (60) is passed through the through hole (43h) of the bobbin (43) and the through hole of the stopper washer (63) and assembled into the sleeve bearing (62).

[0109] Although the present invention has been illustrated and described above with reference to specific preferred embodiments, the present invention is not limited to the embodiments described above, and various changes and modifications may be made by those skilled in the art without departing from the spirit of the invention. Industrial applicability

[0110] The present invention is a fan that can eliminate the insertion of a support seat by employing a sleeve bearing with a closed lower end, and can prevent oil splashing by using a stopper washer without using a separate oil splash prevention washer, while simultaneously blocking the rotation shaft from detaching due to lift force, and can be used as a blower fan for drawing in indoor air of a vehicle or a cooling fan used to prevent overheating of electronic components, etc. Explanation of the symbols

[0111] 10: Housing 10a, 42b, 42c: Through holes 10b,11a: Guide projection 10c: Inner circumference 14a: Air inlet 14b: Air outlet 16: Bridge 20: Impeller 22: Blade 30: Rotor 31: Magnet 32: Back York 33: Rotor support 33a: Disc section 33b: Cylindrical part 34: Axial support part 40: Status 41: Teeth 42: Back yoke 42a,43a-43c: Circular projection 43: Bobbin 43e: Medial guide 43f: Bobbin extension 43g, 43h: Through hole 430a-430d: Guide protrusion 44: Coil 45: Stator Core 50: PCB 51: Output connector 52: Harness 53: Pin terminal 60: Rotation axis 60a: First groove 60b: Anti-detachment groove 61: Bearing housing 61a: Groove 61b-61d: Step section 62: Sleeve bearing 62a; main body 62b; inclined part 62c; middle section 62d; lower section 62e, 62h, 62i; groove 62f; inclined part 62g; top surface 62j; slot 63: Stopper washer 64a-64c: Connecting projection 11: Base 100: Cooling fan

Claims

Claim 1 delete Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete Claim 7 A fan housing having a cylindrical inner circumference; a base integrally formed with a bearing housing having a groove in the center and a protruding outer circumference, connected to a plurality of bridges extending from the rear surface of the fan housing to the center; a sleeve bearing having a circular groove formed in the center from the top to the middle, with the outer circumference inserted and supported into the groove of the bearing housing; a rotating shaft whose lower portion is inserted into the circular groove of the sleeve bearing and is rotatably supported; a rotor fixed to the upper portion of the rotating shaft; and a stator fixed on the base, the outer circumference facing the rotor and the inner circumference coupled to the outer circumference of the bearing housing, and comprising a stator core and a bobbin surrounding the teeth and back yoke of the stator core. A fan comprising: an impeller integrally formed on the outer circumference of the rotor; wherein the bobbin of the stator has a bobbin extension extending from the upper surface of the stator into the interior of the bearing housing; a first stepped portion (61b) is formed on the upper inner circumference of the bearing housing (61); a circular groove space having a trench-shaped cross section is formed between the first stepped portion (61b) and the bobbin extension portion (43f); an outer circumference is disposed in the circular groove space; and a stopper washer (63) of a C-ring structure is movably disposed on the inner circumference so as to be close to the anti-detachment groove of the rotation shaft. Claim 8 A fan according to claim 7, wherein a plurality of outer guide protrusions are protruded on the outer side of the bobbin to define a coil winding area corresponding to the teeth of the stator core, and an inner guide corresponding to the outer guide protrusions is protruded in a ring shape on the inner side. Claim 9 In claim 7, the fan comprises a rotor formed in a cylindrical shape with a certain gap on the outer surface of the stator and having a structure in which N and S poles are alternately divided and magnetized, and a rotor support (33) formed integrally with the magnet and impeller (20) by injection molding using a plastic magnet. Claim 10 delete Claim 11 delete Claim 12 delete Claim 13 delete

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