KR20240163268A - Sleeve Bearing and Axial Type Fan Using the Same - Google Patents

Abstract

The present invention provides an axial fan that can simplify the manufacturing process, reduce the manufacturing cost, and improve durability by eliminating the insertion of a support sheet by adopting a sleeve bearing with a closed lower end to support a rotating shaft.
A fan according to the present invention comprises: a fan housing having a cylindrical inner circumference; a base connected from a rear surface of the fan housing through a plurality of bridges and having a bearing housing protruding from a central portion integrally formed; a sleeve bearing inserted into the bearing housing; a rotary shaft having a lower portion rotatably supported by the sleeve bearing; a rotor fixed to an upper portion of the rotary shaft; a stator fixed on the base, the inner circumference of which is coupled to the outer circumference of the bearing housing and is arranged with a predetermined gap from the rotor; and an impeller integrally formed on the outer circumference of the rotor and rotated together with the stator; wherein the sleeve bearing is characterized in that the bottom portion of a groove with which a lower portion of the rotary shaft comes into contact is blocked.

Description

Sleeve Bearing and Axial Type Fan Using the Same {Sleeve Bearing and Axial Type Fan Using the Same}

The present invention relates to an axial fan, and more particularly, to a sleeve bearing and an axial fan using the same, which can eliminate the insertion of a support sheet by adopting a sleeve bearing with a closed lower end to support a rotating shaft, thereby simplifying the manufacturing process, reducing the manufacturing cost, and improving durability.

Currently, in order to create a comfortable environment inside a car, the vehicle's air conditioning system measures the temperature, humidity, and fine dust inside the car, and then performs heating and cooling inside the car based on the temperature and humidity data, and operates an electric dust filter based on the fine dust data.

One way to check the temperature and humidity inside the vehicle is to use the motor equipped in the In-Car sensor to create a forced airflow by sucking in indoor air and measure the temperature and humidity to check the environmental conditions inside the vehicle.

In addition, as interest in fine dust has recently increased, the concentration of fine dust is measured to check the indoor condition. Fine dust measurement also uses a method of sucking indoor air using a motor equipped in a fine dust sensor.

In-Car Sensor and Fine Dust Sensor are also installed on the grill or instrument panel of the car, and suck in the car's interior air by aspirator method to detect the temperature and fine dust concentration (or fine dust amount) of the interior air. In this case, the fine dust sensor can measure the fine dust amount by irradiating a certain light on the sucked interior air and measuring the amount of light scattered by fine dust in the air.

Conventional blower fans (i.e. aspiration motors) installed in the engine compartment to suck in interior air of a car are compact and do not require precise and complex speed control, so a single-phase motor with a simple structure and one coil is used.

The above blower fan is an axial fan that draws in outside air from an air intake port on one side of the housing and then discharges it through an air exhaust port on the other side along the axial direction, and can be installed in the passage of the housing. In addition, cooling fans used to prevent overheating of electronic components are also axial fans.

A conventional axial fan motor has a housing made of resin, and a bushing made of brass that acts as a bearing housing is formed in the center by insert injection, and a sleeve bearing is inserted into the bushing to rotatably support the rotational axis of the rotor.

In addition, a support sheet is inserted into the lower part of the bearing housing to reduce the rotational resistance of the rotating shaft, and is impregnated with oil. In this case, when the temperature rises due to the rotation of the rotor, the oil may rise along the rotating shaft and fly as the air and oil inside the bearing housing expand in volume due to thermal expansion. In this case, if the bearing housing made of a metal material is press-fitted into the housing made of a resin, the heat dissipation is poor, so if the temperature rise becomes large, oil fly easily occurs.

Furthermore, conventionally, when a through-type sleeve bearing is adopted, a support sheet is inserted into the lower part of the bearing housing in order to reduce the rotational resistance of the rotational shaft extending to the lower part of the sleeve bearing. However, during the process, the support sheet is sometimes omitted when inserted, and is not placed in a predetermined position, causing various problems. In addition, the problem of reduced durability due to wear of the support sheet also occurs.

In addition, conventional aspiration motors have a problem in which the rotation shaft is disengaged by the lifting force when the rotor (impeller) rotates, and to prevent this, a structure is adopted in which a slit washer is combined with a groove formed at the lower end of the rotation shaft. However, in this case, when the rotation shaft rises due to the lifting force when the rotor (impeller) rotates, a problem occurs in which noise is generated when the slit washer comes into contact with the sleeve bearing.

Furthermore, conventional fan motors can be configured to have a rotor by using a method of attaching a magnet to an impeller using a bond such as a back yoke, or by insert molding the magnet and back yoke when the impeller is injected.

The above-mentioned insert molding type and bond assembly method result in increased unit price, and since there is an assembly tolerance, there is a problem of adversely affecting the balance, so balance correction is performed by inserting a balance correction chip or other weight.

In addition, conventional fan motors require bonding and caulking work on the contact surface between the stator and the bushing to prevent the stator from detaching and rotating when assembling the stator to the bushing, which reduces productivity.

: Korean Patent Publication No. 10-2019-0066898

Accordingly, the present invention has been proposed to solve the problems of the above-mentioned prior art, and its purpose is to provide a sleeve bearing and an axial fan using the same, which can eliminate the insertion of a support sheet by adopting a sleeve bearing with a closed lower end to support a rotating shaft, thereby simplifying the manufacturing process, reducing the manufacturing cost, and improving durability.

Another object of the present invention is to provide an axial fan capable of preventing oil from splashing and blocking the rotation shaft from coming off due to lift without using a separate oil splash prevention washer by inserting a stopper washer whose outer circumference is arranged between a bobbin extension and a stepped portion at the top of a bearing housing and whose inner circumference is close to a separation-prevention groove of a rotation shaft.

Another object of the present invention is to provide an axial fan that can simply prevent the detachment and rotation of the stator by assembling a plurality of connecting projections extended from the bearing housing into through holes of the stator and then fixing the exposed leading ends by high-frequency heat fusion when assembling the stator to the bearing housing.

Another object of the present invention is to provide an axial fan that can omit a back yoke by forming the entire impeller and the magnet portion as one piece using a plastic magnet, insert-molding only the shaft, and then magnetizing only the desired inner portion to form an N/S magnet.

In order to achieve the above object, a sleeve bearing according to one feature of the present invention is a sleeve bearing that rotatably supports a rotary shaft, the sleeve bearing comprising: a main body formed in a cylindrical shape and press-fitted to an inner circumference of a groove of a bearing housing; a middle portion having an outer diameter smaller than that of the main body through an inclined portion on a lower side of the main body; and a lower portion extended below the middle portion; characterized in that a circular groove into which the rotary shaft is inserted is formed in the central portion from the upper portion of the main body to the middle portion, and a bottom portion of the groove with which the lower portion of the rotary shaft comes into contact is blocked.

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

According to one feature of the present invention, a fan comprises: a fan housing having a cylindrical inner circumference; a base connected from a rear surface of the fan housing through a plurality of bridges and having a bearing housing protruding from a central portion integrally formed therewith; a sleeve bearing inserted into the bearing housing; a rotary shaft having a lower portion rotatably supported by the sleeve bearing; a rotor fixed to an upper portion of the rotary shaft; a stator fixed on the base, the inner portion of which is coupled to the outer circumference of the bearing housing and is arranged with a predetermined gap from the rotor; and an impeller integrally formed on the outer circumference of the rotor and rotated together therewith; wherein the sleeve bearing is characterized in that the bottom portion of a groove with which a lower portion of the rotary shaft comes into contact is blocked.

A fan according to one feature of the present invention may further include a stopper washer having an outer circumference disposed on a stepped portion at the top of the bearing housing and an inner circumference close to a detachment prevention groove of the rotation shaft.

In addition, the inner diameter of the through hole formed in the inner portion of the stuffer washer may be set to be smaller than the outer diameter of the rotating shaft and larger than the outer diameter of the anti-separation groove.

As described above, in the present invention, by adopting a sleeve bearing with a closed lower end to support the rotary shaft, the insertion of a support sheet is eliminated, thereby simplifying the manufacturing process, reducing the manufacturing cost, and improving durability.

As a result, in the past, when a through-type sleeve bearing was adopted, a support sheet was inserted into the lower part of the bearing housing in order to reduce the rotational resistance of the rotational shaft. However, during the manufacturing process, various problems occurred due to the support sheet being omitted and not being placed in a predetermined position, and a problem of reduced durability due to wear of the support sheet also occurred. However, in the present invention, since a sleeve bearing with a closed lower part is adopted and the insertion of the support sheet is eliminated, the manufacturing process is simplified, the manufacturing cost can be reduced, and the problem of reduced durability due to wear of the support sheet is also solved.

In addition, in the present invention, by inserting a stopper washer whose outer circumference is arranged between the bobbin extension and the step portion at the top of the bearing housing and whose inner circumference is close to the separation-prevention groove of the rotary shaft, oil can be prevented from being sprayed and the rotary shaft can be prevented from being separated by lift without using a separate oil-spray prevention washer. In addition, by minimizing the open space between the bobbin and the sleeve bearing, oil leakage can be prevented to the greatest extent, thereby increasing reliability.

In the past, noise was generated by combining a slit washer with a 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 using a slit washer and without generating noise.

Furthermore, in the present invention, the entire impeller and the magnet portion are formed using a plastic magnet, only the shaft is insert-molded and injected, and then only the desired inner portion is magnetized to form the N/S magnet, thereby allowing the back yoke to be omitted.

Magnets are usually divided into anisotropic and isotropic magnets, but plastic magnets can be anisotropic if the magnet thickness is 1.5t or more, so there is no need for a back yoke.

As a result, in the present invention, since the back yoke is omitted from the overall structure by using a plastic magnet, and the thickness of the general injection-molded material surrounding the magnet and the back yoke is omitted, the magnet area can be maximized in the same size, thereby increasing the effective magnetic flux density and thus improving the efficiency of the motor. In addition, since it is easy to manufacture and the assembly tolerance is minimized, it is also advantageous in terms of balance and reducing the unit price.

Furthermore, in the present invention, when assembling the stator to the bearing housing, the stator can be simply prevented from detaching and rotating by engaging a plurality of connecting projections extended from the bearing housing into through holes of the stator and then fixing the exposed tip portions by high-frequency heat welding.

That is, in the present invention, by forming the bearing housing integrally with the base, the bushing made of brass that functions as the bearing housing can be omitted, and the problem of reduced productivity due to bonding and caulking work on the contact surface of the stator and the bushing when assembling the stator and the bushing in the past can be easily prevented from detaching and rotating the stator by fixing the tip of the connecting projection extended from the bearing housing by high-frequency heat fusion.

FIGS. 1A and 1B are a perspective view and a bottom view, respectively, of an axial fan according to a preferred embodiment of the present invention.
Figure 2 is an axial cross-sectional view of an axial fan according to a preferred embodiment of the present invention.
Figure 3 is a diametrical cross-sectional view of an axial fan according to a preferred embodiment of the present invention.
Figure 4 is an exploded perspective view of an axial fan according to a preferred embodiment of the present invention.
Figure 5 is an exploded perspective view of each module of an axial fan according to a preferred embodiment of the present invention.
Fig. 6 is a perspective view showing the stator assembled into the bearing housing in Fig. 5.
Figure 7 is an enlarged perspective view of the bobbin.
FIGS. 8A to 8E are a perspective view of an erected state, a perspective view of an unfolded state, a plan view, a bottom view, and a longitudinal cross-sectional view, respectively, of a sleeve bearing according to a preferred embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the attached drawings.

In this process, the size and shape of the components depicted in the drawings may be exaggerated for clarity and convenience of explanation. In addition, terms specifically defined in consideration of the configuration and operation of the present invention may vary depending on the intention or custom of the user or operator. The definitions of these terms should be made based on the contents throughout this specification.

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

The attached FIGS. 1a and 1b are a plan view and a perspective view, respectively, showing an axial fan according to a preferred embodiment of the present invention, and FIG. 2 is a cross-sectional view showing an axial fan according to a preferred embodiment of the present invention.

First, an axial fan (100) according to an embodiment of the present invention, as shown in FIGS. 1A and 2, comprises: a fan housing (10) having an air discharge port (14b) formed on the front through which air is discharged, and an air inlet port (14a) formed on the back through which air is introduced; a base (11) connected from the back of the fan housing (10) through a plurality of bridges (16) and supporting a sleeve bearing (62), a PCB (50), a stator (40), and an impeller (20), etc., and having a bearing housing (61) protruding from the center integrally formed; a sleeve bearing (62) inserted into the bearing housing (61); a rotational shaft (60) whose lower part is rotatably supported by the sleeve bearing (62); a rotor (30) fixed to the upper part of the rotational shaft (60); a stator (40) which is fixedly joined to the outer periphery of the bearing housing (61) and arranged with a predetermined gap from the rotor (30); It includes an impeller (20) formed integrally on the outer periphery of a rotor (30) and rotating together with it, and a printed circuit board (PCB) (50) on which various circuit components of a motor drive circuit for fan control are mounted, which is fixedly positioned between the upper part of the base (11) and the lower part of the stator (40) and supplies a motor drive signal to the stator (40).

The fan housing (10) above is open on the front and back to allow air to pass through as the base (11) is connected from the back through a plurality of bridges (16).

In addition, a plurality of guide protrusions (11a) are protruded from the outer periphery of the base (11) at intervals to guide a printed circuit board (PCB) (50) fixed to the upper portion of the base (11).

Furthermore, the fan housing (10) has an inner periphery (10c) that is formed in a cylindrical shape and an outer periphery that is formed in a roughly rectangular shape. Through holes (10a) necessary for fixing the fan (100) to the main body using fixing bolts or screws are formed at four corners of the rectangle, and a guide protrusion (10b) protrudes from one corner to guide and organize a harness (52) that is pulled out from the PCB (50).

The bearing housing (61) formed integrally with the above base (11) has a structure in which 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), whose lower end is closed as described later, is positioned on the bottom of the groove (61a).

The groove (61a) of the above bearing housing (61) is impregnated with oil to reduce the rotational resistance of the rotation shaft (60).

A second step (61c) is formed on the outer circumference of the bearing housing (61) in which the inner circumference of the stator (40) is press-fitted and fixed at the middle position, and a third step (61d) is formed on the lower side of the outer circumference in which the inner circumference of the PCB (50) is secured.

The above PCB (50) is formed in a circular shape with an open center to be inserted into the outer surface of the bearing housing (61), and a harness (52) is connected to one side of the PCB (50) for electrical connection with the main body in which the fan (100) is used, and the tip of the harness (52) is pulled outward and an output connector (51) is connected.

The above bearing housing (61) is formed in a cylindrical shape protruding from the center of the base (11), and the inner circumference of the stator (40) is press-fitted and fixed to the outer surface thereof.

The above stator (40) includes, as shown in FIGS. 4 and 5, a stator core (45) whose 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 on the coil winding area of the bobbin (43) and to which a motor driving signal is applied.

The above bobbin (43) has four outer guide projections (430a-430d) protruding on the outside to define four coil winding areas corresponding to four teeth (41), and the inner guide (43e) corresponding to the outer guide projections (430a-430d) protrudes in a ring shape.

The above stator core (45) has a plurality of teeth (41) formed in a 'T' shape radially extending on the outside of the annular yoke (42). In this case, a single circular protrusion (42a) having a through hole (42b) formed therein may protrude on the outside of the annular yoke (42).

As described later, after assembling the stator (40) to the outer periphery of the bearing housing (61), one of a plurality of, for example, four, connecting projections (64a-64d) protruding from the bearing housing (61) can pass through the through hole (42b) of the above-mentioned circular projection (42a) to secure the stator (40).

In addition, among the four connecting projections (64a-64d), three connecting projections (64a-64d) are connected to through holes (42c) formed in three circular projections (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).

In this case, both the circular projections (42a) and the circular projections (43a-43c) are arranged between the teeth and serve to support four connecting projections (64a-64d).

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

A first step (61b) is formed on the upper inner circumference of the bearing housing (61), and a circular groove space with a trench-like cross-section is formed between the first step (61b) and the bobbin extension (43f).

In the above circular groove space, a stopper washer (63) is inserted, the outer circumference of which is arranged and the inner circumference thereof is close to the anti-separation groove (60b) of the rotation shaft (60). In this case, the stopper washer (63) can be a C-ring or an O-ring.

In this case, the stopper washer (63) is arranged so as to be movable in the circular groove space, and is not maintained in a fixed state. In this case, when the stopper washer (63) of the C-ring structure that is movable is arranged so as to be displaceable in the circular groove space, 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 surface is spread out in the radial direction.

The above stopper washer (63) can prevent the rotation shaft (60) from being disengaged by lifting force as the inner portion thereof is positioned close to the disengagement prevention groove (60b) of the rotation shaft (60).

In addition, since the stopper washer (63) is set to have an inner and outer diameters such that the outer diameter is positioned at the first step (61b) of the upper inner portion of the bearing housing (61) and the inner diameter approaches the anti-separation groove (60b) of the rotation shaft (60), when the temperature rises due to the rotation of the rotor (30), the oil can return to the inside of the bearing housing (61) while preventing the oil from flying as it comes into contact with the lower surface of the stopper washer (63), even if the oil rises along the rotation shaft (60) due to the volume expansion of the air and oil inside the bearing housing (61) due to thermal expansion.

As a result, in the present invention, the stopper washer (63) not only prevents the rotation shaft (60) from being detached, but also prevents oil from being splashed without using a separate oil splash prevention washer.

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

In the present invention, when forming the entire impeller (20) and the magnet (31) portion of the rotor (30) as one piece using a plastic magnet, only the shaft (60) is insert-molded in the center and injection-molded, and then only the desired inner portion is split-magnetized to form the N-pole and S-pole magnets (31), so that the rotor (30) and the impeller (20) can be formed as one piece.

Magnets are usually divided into anisotropic and isotropic, but plastic magnets can be manufactured as extremely anisotropic magnets that do not require a back yoke of the rotor if the magnet thickness is 1.5t or more.

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

The above plastic magnet is a polymer bonded magnet, and is made by mixing polymer resin with iron oxide (SrO ₆ Fe ₂ O ₃ ) mixed with strontium, barium and ferrite as its main raw material. Using this, the impeller and rotor are integrally injection-molded, and only the inner portion is magnetized to form an N/S magnet, thereby enabling boundary forming and allowing the back yoke to be omitted.

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.

In the present invention, a plastic magnet may be used, for example, a magnet in which iron oxide or samarium powder is mixed with nylon.

In the past, when manufacturing an integrated rotor impeller, the impeller and rotor support were formed using only nylon resin, and separately prepared magnets and back yoke were manufactured by insert molding.

As a result, when manufacturing a rotor-integrated impeller that can omit a 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 case of manufacturing a rotor-integrated impeller by insert molding separately prepared magnets and a back yoke.

Accordingly, in the present invention, since a plastic magnet is used, the back yoke is omitted from the overall structure, and the thickness of the general injection-molded material surrounding the magnet and the back yoke is omitted, so that the magnet area can be maximized in the same size, thereby increasing the effective magnetic flux density and thus improving the efficiency of the motor. In addition, since it is easy to manufacture and the assembly tolerance is minimized, it is also advantageous in terms of balance and reducing the unit price.

The above rotor support (33) is manufactured together with an impeller (20) using a plastic magnet, and includes a disc portion (33a) formed in the shape of a disc with a rotation shaft (60) connected to the center, and a cylindrical portion (33b) extending vertically from an edge of the disc portion (33a), having a magnet (31) arranged on the inner surface thereof, and an impeller (20) formed on the outer surface thereof.

In the center of the disc portion (33a) of the above rotor support (33), a shaft support portion (34) extends vertically to support a rotation axis (60).

The impeller (20) is formed integrally with the rotor support (33) using a plastic magnet, 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 while the rotation shaft (60) is placed in the mold, so that the blades (22) of the impeller (20) and the rotor support (33) are formed integrally, and the rotation shaft (60) is fixed to the rotor support (33) by insert molding.

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

The rotating shaft (60) formed integrally in the center of the rotor support (33) by an insert injection method has a first annular groove (60a) and an annular detachment prevention groove (60b) formed on the upper portion.

The first groove (60a) is intended to prevent separation while increasing the mutual joining area with the rotor support (33), and the detachment prevention groove (60b) is intended to prevent separation of the rotary shaft (60) from the sleeve bearing (62) when the lower end of the rotary shaft (60) passes through the through hole (43h) of the bobbin (43) and then is pressed through the inner peripheral through hole of the stopper washer (63) and is once coupled to the sleeve bearing (62).

In this case, the stopper washer (63) may use a C-ring structure that can be restored to its original position by tension after the outer surface is spread out in the radial direction when a vertical load is applied.

A slanted portion (62f) is formed on the upper portion of the sleeve bearing (62) to guide the lower portion of the rotary shaft (60) to make entry easier when inserted into the through hole (62e).

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

As a result, when the lower part of the rotary shaft (60) is pressed through the through hole of the stopper washer (63) and once coupled to the sleeve bearing (62), even if a lifting force is generated that causes the impeller (20) and the rotary shaft (60) to rise as the rotor (30) rotates, the rotary shaft (60) can be prevented from being separated from the sleeve bearing (62) as the lower part of the separation prevention groove (60b) is caught on the lip of the through hole.

In addition, 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) can barely pass, and the bottom surface of the stopper washer (63) is in contact with the upper portion of the bearing housing (61).

As a result, in the present invention, by forming the inner circumference of the stopper washer (63) close to the anti-separation groove (60b) of the rotation shaft (60), even if the air and oil inside the bearing housing (61) rise along the rotation shaft (60) due to thermal expansion as the rotor (30) rotates, they are caught on the lower 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.

Furthermore, as shown in FIGS. 3 to 6, when the stator (40) is assembled to the sleeve bearing (62), four connecting projections (64a-64d) protruding from the bearing housing (61) are joined to a through hole (43g) formed in the bobbin extension (43f) of the bobbin (43) and a through hole (42b) of the circular projection (42a), so that the tip end protrudes to the upper portion of the bobbin (43).

Therefore, in the present invention, by fusing four connecting projections (64a-64d) protruding from the upper portion of the bobbin (43) using a high-frequency heat fusion method, the connection between the bearing housing (61) and the bobbin (43) can be easily made, and as a result, detachment and rotation of the stator (40) can be prevented.

Meanwhile, in the present invention, as shown in FIG. 2 and FIG. 8a to FIG. 8e, by adopting a sleeve bearing (62) with a closed lower end to support a rotation shaft (60), the insertion of a support sheet is eliminated, thereby simplifying the manufacturing process, reducing the manufacturing cost, and improving durability.

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

The outer circumference of the main body (62a) of the above sleeve bearing (62) is maintained in a fixed state by being press-fitted to the inner circumference of the groove (61a) of the bearing housing (61), and it is preferable that the middle portion (62c) and the lower portion (62d) 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).

The above sleeve bearing (62) is formed in an overall cylindrical shape, and has a structure in which a circular groove (62e) is formed in the center and faces downward from the main body (62a) to the middle portion (62c), and the lower portion (62d) is closed.

The lower portion (62d) has a structure in which the bottom of the groove (62e) that the lower portion of the rotary shaft (60) comes into contact with is blocked, and in the illustrated embodiment, a slot (62j) is formed that forms a plurality of, for example, four, oil circulation paths that lead from the groove (62e) to the outside, and can be communicated with the groove (62e). In this case, the lower portion (62d) may also have a structure in which the slot (62j) that leads from the groove (62e) to the outside is not formed and is blocked.

In addition, an inclined portion (62f) may be formed between the upper surface (62g) of the sleeve bearing (62) and the central groove (62e) to smoothly guide the insertion of the rotation shaft (60) into the groove (62e).

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). As the temperature rises with the rotation of the rotor (30) and the rotary shaft (60), the oil inside the bearing housing (61) expands in volume due to thermal expansion, and the oil rises along the rotary shaft (60), then gets caught on the lower surface of the stopper washer (63) and returns to the grooves (62e) inside the bearing housing (61), thereby forming an oil circulation path.

As a result, conventionally, a support sheet is inserted into the lower part of the bearing housing to reduce the rotational resistance of the rotating shaft by adopting a through-type sleeve bearing. However, during the manufacturing process, the support sheet is sometimes omitted when inserted, and is not placed in a predetermined position, causing various problems. In addition, the problem of reduced durability due to wear of the support sheet also occurs.

However, in the present invention, the manufacturing process is simplified and the manufacturing cost can be reduced by eliminating the insertion of the support sheet while adopting a sleeve bearing (62) having a structure in which the bottom part of the groove (62e) with which the lower part of the rotary shaft (60) comes into contact is blocked, and the problem of reduced durability due to wear of the support sheet is also solved.

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

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

In the description of the embodiment of the present invention, a fan motor (80) with a 4-slot-4-magnet structure in a single-phase motor method is disclosed, but it can be configured as a BLDC motor with a 3-phase drive method.

Various circuit components of a motor drive circuit that controls a fan are mounted on the above PCB (50), 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.

In addition, as described later, the stator (40) is press-assembled with three pin terminals (53) penetrating the bobbin (43) and the lower part of the pin terminals (53) being soldered and fixed to the PCB (50), so that stable physical support can be achieved between the stator (40) and the PCB (50).

Below, a fan assembly process according to one embodiment of the present invention is described.

First, the stator (40) is formed integrally by insert molding using resin, with a bobbin (43) having a bobbin extension (43f) extended from the upper portion while covering the coil winding area on the outer periphery of the stator core (45) with an insulator. A coil (44) is wound on the outer periphery of the coil winding area to complete the stator (40).

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

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

Meanwhile, a base (11) is connected to the back surface of the fan housing (10) through a plurality of bridges (16), and a bearing housing (61) protrudes from the center of the base (11) to form an integral part.

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

Thereafter, the stator (40) with the PCB (50) mounted on the lower part is coupled to the outer periphery of the bearing housing (61). In this case, the four connecting projections (64a-64d) protruding from the bearing housing (61) have their ends protruded to the upper part of the bobbin (43) through the through hole (43g) formed in the bobbin extension (43f) of the bobbin (43).

Next, the connection between the bearing housing (61) and the bobbin (43) is secured by heat-melting the four connecting projections (64a-64d) protruding from the upper portion of the bobbin (43) to the upper portion of the bobbin (43) using a high-frequency heat-melting method. As a result, the stator (40) can be prevented from being separated from or rotating in the bearing housing (61).

Finally, using a plastic magnet, the entire impeller (20) and the magnet (31) portion are formed as one piece, and only the shaft (60) is insert-molded and injected, and then only the desired inner portion is magnetized to selectively form the N/S magnet (31).

Next, the lower part of the rotation shaft (60) is assembled to the sleeve bearing (62) by passing it through the through hole (43h) of the bobbin (43) and the through hole of the stopper washer (63).

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

The present invention is a fan which can eliminate the insertion of a support sheet by adopting a sleeve bearing with a closed lower part, and can prevent oil splashing without using a separate oil splash prevention washer by using a stopper washer, and at the same time, can block the rotation shaft from being separated by lift, and can be used in a blower fan that sucks in interior air of a vehicle, a cooling fan used to prevent overheating of electronic components, etc.

10: Housing 10a,42b,42c: Through hole
10b,11a: Guide protrusion 10c: Inner part
14a: Air inlet 14b: Air outlet
16: Bridge 20: Impeller
22: Blade 30: Rotor
31: Magnet 32: Back yoke
33: Rotor support 33a: Disc section
33b: Cylinder 34: Axial support
40: STATER 41: TISS
42: Back yoke 42a,43a-43c: Circular protrusion
43: Bobbin 43e: Inner guide
43f: Bobbin extension 43g, 43h: Through hole
430a-430d: Guide lug 44: Coil
45: Stator core 50: PCB
51: Output connector 52: Harness
53: Pin terminal 60: Rotating shaft
60a: 1st groove 60b: Anti-separation groove
61: Bearing housing 61a: Groove
61b-61d: Stepped section 62: Sleeve bearing
62a; body 62b; slope
62c; middle 62d; bottom
62e,62h,62i; Home 62f; Slope
62g; top surface 62j; slot
63: Stopper washer 64a-64c: Connecting lug
11: Base 100: Cooling Fan

Claims (4)

As a sleeve bearing that rotatably supports a rotating shaft,
A main body having a cylindrical shape and being press-fitted to the inner periphery of the groove of the bearing housing;
A stop portion having an outer diameter smaller than that of the main body through an inclined portion on the lower side of the main body; and
A lower portion extending from the lower side of the above-mentioned stop portion;
A sleeve bearing in which a circular groove is formed in the center from the upper part of the main body to the middle part into which the rotation shaft is inserted, and the bottom part of the groove with which the lower part of the rotation shaft comes into contact is blocked. In the first paragraph,
A sleeve bearing further comprising at least one slot forming an oil circulation path leading from the groove to the outside. A fan housing having a cylindrical inner portion;
A base formed integrally with a bearing housing protruding from the center and connected through a plurality of bridges from the back surface of the fan housing;
A sleeve bearing inserted into the above bearing housing;
A rotary shaft having a lower portion rotatably supported on the sleeve bearing;
A rotor fixed to the upper part of the above rotating shaft;
A stator fixed on the base and having an inner circumference joined to the outer circumference of the bearing housing and positioned with a predetermined gap from the rotor; and
It includes an impeller formed integrally on the outer periphery of the rotor and rotates together with it;
The above sleeve bearing is a fan having a structure in which the bottom part of the groove that makes contact with the lower part of the above rotary shaft is blocked. In the third paragraph
A fan further comprising a stopper washer having an outer circumference disposed on a stepped portion at the top of the bearing housing and an inner circumference close to a separation-prevention groove of the rotation shaft.

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