KR20040065529A - A brushless dc motor - Google Patents

Abstract

PURPOSE: A brushless DC motor is provided to reduce vibration of a stator due to electromagnetic force when driving the motor and improve stability for the insulation and the corrosion. CONSTITUTION: A brushless DC motor comprises a cylinder type stator molding body(10), a first housing(20), a second housing(30), a rotor(40), and a motor driving control circuit board(50). The first housing includes a shaft supporting hole and coupled to the stator molding body to form space between one side of the stator molding body and the inside surface at one side of the stator molding body. The second housing includes a shaft supporting hole and coupled to the stator molding body at the other side of the stator molding body.

Description

Brushless DC Motors {A BRUSHLESS DC MOTOR}

The present invention relates to a brushless direct current motor, and more particularly, because the stator is molded with a resin to minimize the vibration of the stator due to the electromagnetic force during rotation of the rotor and to maintain the concentricity to influence the alignment of the motor shaft as well as insulation and The present invention relates to a brushless DC motor capable of increasing stability against corrosion.

Brushless DC motors (BLDC Motors) are characterized by the absence of mechanical contacts, namely brushes and commutators, compared to conventional brushed DC motors. It is often used depending on the development of parts and materials. In general, BLDC motors are classified into radial gap type and axial gap type, and radial gap type BLDC motors have outer rotor type according to the arrangement of the magnet rotor. ) And Inner Rotor Type. The present invention relates to an internal rotor type BLDC motor mainly used where the motor structure can be configured relatively simply and where relatively sensitive controllability is required.

In general, the internal rotor type BLDC motor has a structure in which a rotor of a cylindrical structure is rotatably supported inside a donut-shaped stator. The stator has a structure in which a coil is wound around a core formed by stacking iron pieces, and the stator is fixed inside the case or housing of the motor.

However, the conventional brushless DC motor has a problem such that noise is generated by the stator vibrating by the electromagnetic force when the motor rotates. In particular, since the core of the stator is formed by stacking iron pieces, noise caused by vibration of the iron pieces in the stator is particularly problematic.

In addition, in the conventional brushless DC motor, since the stator is fixed inside the housing or the case and the rotor is rotatably supported by the housing or the case, it is difficult to maintain the concentricity of the stator and the rotor that influence the alignment of the motor shaft.

In addition, the conventional brushless DC motor has a disadvantage that the insulation and the outside is incomplete because the core and the coil is exposed, it is vulnerable to corrosion.

The object of the present invention is to solve the problems as described above is an object of the present invention by molding the stator with a resin is fixed stator to prevent noise caused by the vibration of the stator due to the electromagnetic force during the rotation of the motor, integrally with the stator By combining the housing supporting the rotor shaft with the molded body, the brushless DC motor can easily maintain the concentricity that determines the alignment of the motor shaft, and improve the insulation and corrosion stability by enclosing the core and coil with resin. To provide.

1 is an exploded perspective view showing a brushless DC motor according to an embodiment of the present invention;

2 is a partial cross-sectional view showing a brushless DC motor according to an embodiment of the present invention.

3 is an exploded perspective view showing a stator molding body of a brushless DC motor according to an embodiment of the present invention;

4 is a plan view and a side view showing a stator molding body of a brushless DC motor according to an embodiment of the present invention;

5 is a plan view illustrating a stator of a brushless DC motor according to an embodiment of the present invention.

6 is an exploded perspective view showing a coupling relationship between a stator molding body and a motor drive control circuit board of a brushless DC motor according to an embodiment of the present invention;

7A and 7B are cross-sectional views conceptually illustrating a state in which a stator of a brushless DC motor according to an embodiment of the present invention is accommodated in a mold;

8 is a partial cross-sectional view showing the rotor of the brushless DC motor according to an embodiment of the present invention.

9 is a cross-sectional view showing a cross section in A-A of FIG.

<Short description of the major reference symbols>

10 Stator molding 11 core

12 bobbins and 13 coils

13a terminal pin 14 stator

15 Resin 16 Through Hole

17 Heat radiation fins 18 Blowing duct

19 Sensor support groove 20 First housing

22 Outlet port 26 Terminal pin support

26a pin hole 26b taper of terminal pin support

30 2nd housing 32 Inlet

40 rotor 41 rotor shaft

41a turning or groove 43 magnet

43a pole split 45 magnet ring

45a protrusion or groove 50 motor drive control circuit board

51 Sensor 52 Terminal Socket

53 pin fixing hole 60 blower

61 Blower Fan 63 Blower Guide

65 ventilation housing 70 mold

71 Pin insertion hole 71a Taper part of pin insertion hole

In order to achieve the above object, in the brushless DC motor according to the present invention, a plurality of coils are arranged at regular intervals in a circumferential direction on a core having a through-hole in the center thereof, and a stator having both ends of each of the coils A cylindrical stator molding body integrally molded and enclosed with a resin so as to protrude to one side in the axial direction, and an axial support hole is formed in the center, between one side of the stator molding body and an inner surface at one side of the stator molding body. A first housing coupled to the stator molding body to form a space, a shaft support hole formed in the center, a second housing coupled to the stator molding body on the other side of the stator molding body, and a cylinder fixed to the rotor shaft One end of the rotor shaft supports the shaft of the first housing so that a magnet having a shape is accommodated in the stator molding body and rotated. A circuit for controlling rotation of the rotor, the rotor being supported by the hole and the other end of the rotor shaft being rotated and supported by the shaft support hole of the second housing, and a through hole through which the rotor shaft passes. And a PCB for sensing a rotational position of the rotor, wherein both terminals of each of the coils exposed to one side of the stator molding body are connected to a circuit, and the sensor is connected to one side of the stator molding body. And a motor driving control circuit board accommodated in a space formed by one side of the stator molding body and the inner surface of the first housing so as to be positioned.

Since the stator is molded and enclosed with resin, the iron pieces constituting the stator not only vibrate but also have high stability against insulation and corrosion.

In addition, since the stator is integrated into the stator molding body and the housing in which the rotor shaft is supported is coupled to the stator molding body, the concentricity of the stator and the rotor can be easily maintained, and the assembly of the motor can be facilitated.

In addition, in the brushless DC motor according to the present invention, both terminals of each of the coils are terminal pins protruding to one side of the stator molding body, and the terminal pins are inserted into the motor driving control circuit board so as to be connected to a circuit. Characterized in that the hole is formed for.

The terminal pin is inserted into the end of the hole formed in the mold for molding the stator molding body. As the terminal pin is inserted into the hole of the mold as described above, the resin pin is molded while the bent or twisted terminal pin is positioned at the correct position. Accordingly, the terminal pin is exactly matched to the hole formed in the motor drive control circuit board. Easy to assemble

In addition, the brushless DC motor according to the present invention, the stator molding body is a resin in a state in which the stator is accommodated in the mold formed in the tapered portion having a diameter decrease in the depth direction at the inlet of the pin insertion hole into which the terminal pin is inserted Characterized in that formed by molding.

Accordingly, when the stator is placed in the mold, the terminal pin is easily inserted into the hole of the mold. In addition, one side of the drive control circuit board and the stator molding body is fixed by engaging the drive control circuit board with a tapered portion of the inlet of the hole into which the terminal pin is inserted to wrap the bottom of the terminal pin. To maintain the spacing.

In addition, in the brushless DC motor according to the present invention, the stator molding body is formed by arranging the pin holes for inserting each of the terminal pins in an annular shape and inserted into the taper portion of the pin insertion hole in each of the pin holes. An annular terminal pin support having a tapered portion protruding to the opposite side of the stator molding body is accommodated in the mold in a state in which it is coupled to the stator, and is molded with resin.

The terminal pin supporter inserts the terminal pin of the stator into the pin hole and is pre-coupled to the stator so that the terminal pin of the stator is always inserted to a predetermined depth into the pin insertion hole of the mold, and both ends of the terminal pin and the coil are soldered. In the bonding process, the solder buried in the terminal pin is prevented from being caught in the pin insertion hole of the mold.

In addition, the brushless DC motor according to the present invention is characterized in that a sensor support groove is formed on one side of the stator molding to support a part of the sensor is inserted.

The sensor protrudes from the driving control circuit board toward one side of the stator molding body. As the part of the protruding sensor is accommodated in the sensor support groove, the sensor is seated at the correct position. It will not vibrate.

In addition, the brushless DC motor according to the present invention, characterized in that the heat radiation fin is formed on the outer peripheral surface of the stator molding body.

Heat generated from the stator is smoothly discharged through the heat dissipation fins.

In addition, the brushless DC motor according to the present invention, the inlet is formed through the second housing in place, and the stator molding body in the axial direction from the outside of the stator so that the blower duct is in communication with the inlet Is formed penetrating from the other side of the one side, the discharge port is formed in communication with the blowing duct in place of the first housing, the blowing fan for blowing air to the inlet of the second housing so that the rotor rotates integrally with the rotor And a blower fixed to the rotor shaft extending outwardly of the second housing is installed outside the second housing.

The flow of air generated by the blower as described above cools the heat generated by the stator while passing through the blower duct of the stator molding body. In particular, the brushless DC motor having the above configuration can be used as a blower that can directly suck or blow air, such as a vacuum cleaner or a blow dryer.

In addition, the brushless DC motor according to the present invention is characterized in that the core of the stator is formed by connecting a plurality of core pieces, and the coil is insulated and wound around each of the core pieces.

The stator winds the coil on each of the core pieces and connects it to facilitate winding of the coil.

In addition, the brushless DC motor according to the present invention is characterized in that each of the stator core pieces is inserted into a bobbin of a failure shape, and the coil is wound around the bobbin and insulated from each of the core pieces.

The coil is wound around the bobbin to insert each of the core pieces into the bobbin, thereby facilitating winding of the coil.

In addition, the brushless DC motor according to the present invention, the magnet of the rotor is surrounded by a cylindrical magnet ring, the magnet is characterized in that the molded by injecting a magnet resin in the space between the rotor shaft and the magnet ring .

Accordingly, the magnet is fixed integrally with the rotor shaft, thereby preventing the problem that the magnet is detached from the rotor shaft while breaking the adhesive force caused by bonding and bonding of the rotor shaft by pressing the rotor shaft into a cylindrical magnet and bonding. . In particular, the magnet ring is prevented from scattering the magnet during the high speed rotation of the rotor.

In addition, the brushless DC motor according to the present invention is characterized in that a protrusion or groove is formed on the inner circumferential surface of the magnet ring in contact with the magnet.

Accordingly, the magnet ring is not axially displaced from the magnet, and the magnet and the magnet ring do not turn away from each other.

In addition, the brushless DC motor according to the present invention is characterized in that a protrusion or groove is formed on the outer circumferential surface of the rotor shaft in contact with the magnet.

As a result, the magnet is not axially separated from the rotor shaft, and the magnet and the rotor shaft do not turn away from each other.

Hereinafter, a brushless DC motor according to the present invention will be described in detail with reference to the embodiment shown in the drawings.

1 is an exploded perspective view showing a brushless DC motor according to an embodiment of the present invention, Figure 2 is a partial cross-sectional view showing a brushless DC motor according to an embodiment of the present invention.

Referring to the drawings, the brushless DC motor according to an embodiment of the present invention is a stator molding body 10, the first housing 20, the second housing 30, the rotor 40, the motor drive control circuit board 50, and a blower 60.

The stator molding body 10 is an injection molding of the stator 14 and the resin 15 integrally.

Figure 3 is an exploded perspective view showing a stator molding body of a brushless DC motor according to an embodiment of the present invention, Figure 4 is a plan view showing a stator molding body of a brushless DC motor according to an embodiment of the present invention; Figure 5 is a side view, Figure 5 is a plan view showing a stator of a brushless DC motor according to an embodiment of the present invention.

In the stator molding body 10, a plurality of coils 13 are arranged at regular intervals in a circumferential direction on a core having a through-hole for inserting the rotor 40 in the center thereof, and the stator 14 wound around the stator 14 Both ends of the coils 13a of the coil are exposed to one side in the axial direction so as to be integrally molded with a resin 15 so as to be surrounded by a cylindrical assembly. The rotor 40 is inserted into the through hole 16 formed at the center of the stator molding body 10.

The core of the stator 14 is formed by connecting a plurality of core pieces 11, and the coil 13 is insulated and wound around each of the core pieces. Referring to the drawings, each of the stator core pieces 11 is inserted into a bobbin 12 having a failure shape, and the coil 13 is wound around the bobbin 13 to be insulated from each of the core pieces 11. Terminal pins 13a are fixed to each of the bobbins 13 so as to protrude in the axial direction, and both terminals of the coil 12 are connected to each of the terminal pins 13a.

The stator molding body 10 is formed by injection molding the resin 15 in a state where the stator 14 is accommodated in the mold 70. 7A is a cross-sectional view conceptually illustrating a state in which a stator of a brushless DC motor according to an embodiment of the present invention is accommodated in a mold. Referring to the drawings, the end portion of the terminal pin 13a is inserted into the mold 70 so that the end portion of the terminal pin 13a of the stator 14 protrudes to one side of the stator molding body 10 and is exposed. It is inserted into the hole 71. As described above, when the injection molding of the stator molding body 10 is performed, the terminal pin 13a is inserted into the pin insertion hole 71 to be fixed at the correct position. On the other hand, when the stator 14 is inserted into the mold 70, the terminal pin 13a is inserted into the pin insertion hole 70 so that the inlet of the pin insertion hole 71 has a diameter in the depth direction. This decreasing tapered portion 71a is formed. That is, the inlet of the pin insertion hole 71 has a tapered shape. Accordingly, the resin is filled in the tapered portion 71a so that the bottom of the terminal pin 13a is surrounded by the tapered resin, and the motor drive control circuit 50 is caught by the motor drive control circuit. The substrate 50 is supported apart from one side of the stator molding body at regular intervals. On the other hand, when the terminal pin 13a of the stator 14 is inserted into the pin insertion hole 71 of the mold 70 as described above, it is preferable that the terminal pin 71a is inserted into the pin insertion hole 71 at a constant depth. Do. To this end, the stator molding body 10 is formed by bonding the terminal pin support member 26 to the stator 14 and molding the resin. 3 and 4 illustrate a stator molding body 10 having the terminal pin support 26, and in FIG. 7B, the terminal pin support 26 is coupled to the stator 14 and accommodated in the mold 70. The state is shown conceptually. Referring to the drawings, the terminal pin support 26 is formed in an annular shape in which a pin hole 26a for inserting each of the terminal pins 13a is arranged in an annular shape, and the pin insertion holes are formed in each of the pin holes 26a. A tapered portion 26b for insertion into the tapered portion 71a of 71 is formed to protrude to the opposite side of the stator molding body 10. The terminal pin support 26 inserts the terminal pin 13a of the stator 14 into the pin hole 26a so that the tapered portion 26b is positioned at the distal side of the terminal pin 13a. ) Is combined. The stator 14 to which the terminal pin support 26 is coupled as described above inserts the end of the terminal pin 13a into the pin insertion hole 71 and the taper portion 26b to the tapered portion of the pin insertion hole 71. It inserts into 71a and is accommodated in the metal mold 70. As shown in FIG. As described above, the terminal pin support 26 accommodated in the mold 70 together with the stator 14 is molded in resin integrally with the stator 14 and the resin. As described above, the terminal pin 13a protruding to one side of the stator molding body 10 is inserted into and fixed in the pin fixing hole 53 formed in the motor driving control circuit board 50, and thus the motor driving control circuit board 50 is fixed. Is connected to the circuit formed in On one side of the stator molding body 10, a sensor support groove 19 for inserting and supporting a part of the sensor 51 provided in the motor drive control circuit board 50 is formed. In addition, a heat dissipation fin 17 for dissipating heat generated from the stator 14 is formed on the outer surface of the stator molding body 10. On the other hand, the air blowing duct so that the flow of air formed by the blower 60 is in communication with the inlet 32 of the second housing 30 in the stator molding body 10 to cool the heat generated from the stator 18 is penetrated from one side to the other from the other side of the stator molding body in the axial direction from the outside of the stator. The blower duct 18 communicates with an outlet 22 formed in place of the first housing 20.

The first housing 20 has a shaft support hole formed at the center thereof, and the stator molding body 10 is formed at one side of the stator molding body 10 to form a space between one side and an inner surface of the stator molding body 10. ) Is combined. The motor drive control circuit board 50 is accommodated in a space between the inner surface of the first housing 20 and one side of the stator molding body 10. On the other hand, in place of the first housing 20 is formed with a discharge port 22 for discharging the air blown through the blowing duct 18 of the stator molding body (10).

The second housing 30 has a shaft support hole formed at the center thereof, and is coupled to the stator molding body 10 at the other side of the stator molding body 10. The blower 60 is coupled to an outer side of the second housing 30, and the air blown by the blower 60 is disposed in the second housing 30 of the stator molding body 10. The inlet 32 is formed to flow into the blowing duct 18.

The rotor 40 has one end of the rotor shaft 41 such that a cylindrical magnet 43 fixed to the rotor shaft 41 is accommodated in the through hole 16 of the stator molding body 10 and rotated therein. Is rotatably supported by the shaft support hole of the first housing 20 and the other end of the rotor shaft 41 is rotatably supported by the shaft support hole of the second housing.

8 is a partial cross-sectional view showing a rotor of a brushless DC motor according to an embodiment of the present invention, Figure 9 is a cross-sectional view showing a cross section in A-A of FIG.

Both ends of the rotor shaft 41 are rotatably supported by the first housing 20 and the second housing 30. The rotor shaft 41 is rotated integrally with the magnet 43 is fixed integrally. The rotor shaft 41 is provided with protrusions or grooves 41a at the portions where the magnets 43 are in contact so that the magnets 43 do not fall out in the axial direction or do not waste. As described below, when the magnet 43 is injection-molded such that it is polarly anisotropically oriented as shown in FIG. 9, even if the magnetic flux of the radially symmetrical shape formed by the magnet 43 is changed by the protrusion or the groove 43a, The projections or grooves of the rotor shaft 41 may be symmetrically formed with respect to the pole splitting point 43a of the magnet 43 so as to be symmetrical with respect to the splitting point 43a. In particular, when the magnet 43 is polar anisotropically oriented as described above, an axis center is formed on an inner circumferential surface of the rotor shaft 41 in which the protrusion or groove 41a is in contact with the magnet 43. It is preferable to form at the pole splitting point 43a of the magnet 43 which is symmetrical with each other as a center. This is because the magnetic flux is relatively weak at the pole splitting point 43a so that the distortion of the magnetic flux due to the projections or grooves 41a formed at the pole splitting points 43a of the magnets 43 which are symmetrical with respect to the axis center can be minimized. It is. The drawing shows an embodiment in which the groove is formed around the rotor shaft 41 in the circumferential direction, but only one embodiment is shown in the drawing. That is, the rotor shaft 43 may be formed with a projection or groove extending in the axial direction, such as the projection (45a) of the magnet ring 45.

The magnet 43 is fixed to the rotor shaft 41 as a permanent magnet for generating magnetic flux and is integrally rotated with the rotor shaft 41. The magnet 43 injects a magnet resin into the space between the rotor shaft 41 and the magnet ring 45 in a state where the rotor shaft 41 is accommodated in a predetermined mold (not shown). It is molded integrally with 41. In the rotor 40 according to the present invention, the magnet 43 is formed by injecting the magnet resin around the rotor shaft 41 as described above and integrally formed with the rotor shaft 41. The breakage of the magnet 43 and the detachment of the magnet 43 due to the lowering of the bonding strength are prevented. In particular, when the rotor shaft 41 is press-fitted into the magnet 43, it is not possible to form protrusions or grooves 43a on the outer circumferential surface of the rotor shaft 41 due to the press-fit structure. On the contrary, the rotor 40 according to the present invention has the rotor shaft 41 and the rotor because the magnet resin encloses the protrusion or penetrates the groove even when the protrusion 40 or the groove 41a is formed on the outer circumferential surface of the rotor shaft 41. The magnets 43 mesh with each other. This is the same as in the case of the projection or groove 45a of the magnet ring 45 described below. On the other hand, the magnet resin is generally composed of a mixture of Sr or Ba Ferrite magnetic powder and nylon 6, Nylon 12, PPS (Polyphenylene sulfide) as a binder (Binder). When the magnet resin is injected into the mold to which the magnetic field is applied, the fine particles of the magnet are oriented in the direction of the magnetic field to cool / solidify. FIG. 9 shows an embodiment in which the magnet 43 is injection molded such that it is polar anisotropically oriented.

The magnet ring 45 is a cylinder in which a through hole for inserting and receiving the rotor shaft 41 is formed at the center thereof. The magnet ring 45 is integrally attached to the outer circumference of the magnet 43 during injection molding of the magnet 43. That is, the magnet 43 has the rotor shaft 41 and the magnet ring 45 in a state where the rotor shaft 41 is inserted into the through hole of the magnet ring 45 so as to be concentric with the magnet ring 45. It is molded by injecting a magnet resin into the space between them.

On the other hand, a protrusion or groove 45a is formed on the inner circumferential surface of the magnet ring 45 in contact with the magnet 43. The projections or grooves 45a of the magnet ring 45 are similar to the projections or grooves 41a of the rotor shaft 41 so that the magnet rings 45 do not escape from the magnets 43 and do not turn away from each other. It is for. In addition, when the magnet 43 is injection-molded so as to be anisotropically anisotropically oriented, the protrusions or grooves of the magnet ring 45 may be symmetrically formed with respect to the pole splitting point 43a of the magnet 43. desirable. In particular, when the magnet 43 is injection-molded such that it is polar anisotropically oriented, the inner circumferential surface of the magnet ring 45 in contact with the magnet 43 is symmetrical with each other around the axis center. It is preferable that a projection or groove 45a is formed at the split point 43a. In the figure, an embodiment is shown in which the protrusions or grooves 45a extend in the axial direction at the pole splitting points 43a of the magnets 43 which are symmetrical with each other about an axial center on the inner circumferential surface of the magnet ring 43. have.

The motor drive control circuit board 50 is a PCB board on which a circuit for controlling the rotation of the rotor 40 is detected. 6 is an exploded perspective view illustrating a coupling relationship between a stator molding body and a motor driving control circuit board of a brushless DC motor according to an embodiment of the present invention. The through hole for passing the rotor shaft 41 is formed in the center of the motor drive control circuit board 50, and a sensor 51 for sensing the circuit and the rotational position of the rotor is provided. The sensor 51 is for detecting the rotational position of the rotor 40 from the magnetic field of the rotor 40 like the Hall sensor, for example. When the rotational position of the rotor 40 is sensed by the sensor 51 as described above, the current supplied to the stator 14 is controlled by the preconfigured circuit according to the detected position, thereby controlling the rotor 40. ) Is rotated. The motor driving control circuit board 50 has pins fixed at both terminals 13a of the plurality of coils 13 exposed to one side of the stator molding body 10 on the motor driving control circuit board 50. One side of the stator molding body 10 and the first portion are inserted into and fixed to the hole 53 and connected to a circuit, and a part of the sensor 51 is inserted into and supported by a sensor support hole 19 formed at one side of the stator molding body. It is accommodated and installed in a space formed by the inner surface of the housing 20.

The blower 60 is a blower fan 61 fixed to the rotor shaft 41 extending to the outside of the second housing 30 is integrally rotated with the rotor 40 to the second housing ( It is installed on the outside of the second housing 30 to blow air to the inlet 32 of the 30. The flow of air generated by the rotation of the blower fan 61 flows through the blower guide 63 to the blower duct 18 of the stator molding body 10 through the inlet 32 of the housing. The blowing fan 61 and the blowing guide 63 are covered by a blowing housing 65.

In the brushless DC motor according to the present invention having the configuration as described above, the stator is integrally molded with resin and surrounded by resin, thereby preventing vibration of the stator due to electromagnetic force during operation of the motor as well as insulation and corrosion of the core and coil. Stability of the rotor is improved, and the stator and the housing in which the rotor shaft is supported on the stator molding body are integrally coupled to each other, and thus, the concentricity of the stator and the rotor which aligns the alignment of the motor shaft can be easily maintained.

The brushless DC motor described above and illustrated in the drawings is only one embodiment for implementing the present invention, and should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is defined only by the matters set forth in the claims below, and the embodiments which have been improved and changed without departing from the gist of the present invention will be apparent to those skilled in the art. It will be said to belong to the protection scope of the present invention.

Claims (14)

A plurality of coils are arranged at regular intervals in a circumferential direction on a core having a through-hole formed in the center thereof, and a wound stator is integrally molded with resin so that both terminals of each of the plurality of coils are exposed to one side in the axial direction and surrounded by a cylindrical shape. Of stator moldings, A first housing coupled to the stator molding body so that a shaft support hole is formed at a center thereof, and a space is formed between one side of the stator molding body and an inner surface at one side of the stator molding body; A second housing having a shaft support hole formed at a center thereof and coupled to the stator molding body at the other side of the stator molding body; One end of the rotor shaft is rotatably supported by the shaft support hole of the first housing so that the cylindrical magnet fixed to the rotor shaft is accommodated in the stator molding body, and the other end of the rotor shaft is connected to the second housing. A rotor rotatably supported in the shaft support hole, A through-hole is formed at the center of the through-hole for passing the rotor shaft, a circuit board for controlling the rotation of the rotor and a sensor for sensing the rotation position of the rotor, a PCB substrate, exposed to one side of the stator molding body A motor drive control circuit accommodated in a space formed by one side of the stator molding body and an inner surface of the first housing such that both terminals of each of the plurality of coils are connected to a circuit and the sensor is located on one side of the stator molding body. Brushless direct current motor comprising a substrate. The method of claim 1, Both terminals of the coil are terminal pins with one end protruding to one side of the stator molding body, And a pin fixing hole for inserting the terminal pin to be connected to the circuit in the motor driving control circuit board. The method of claim 2, The stator molding body is formed by molding a resin in a state in which the stator is accommodated in a mold having a tapered portion whose diameter decreases in a depth direction at an inlet of a pin insertion hole into which the terminal pin is inserted, wherein the brushless DC motor . The method of claim 3, The stator molding body has a pin hole for inserting each of the terminal pins in an annular shape, and a taper portion for inserting into the taper portion of the pin insertion hole in each of the pin holes protrudes to the opposite side of the stator molding body. Brush-shaped DC motor, characterized in that the ring-shaped terminal pin support is formed in the resin is accommodated in the mold in the state coupled to the stator. The method according to any one of claims 1 to 4, Brushless DC motor, characterized in that the sensor support groove is formed on one side of the stator molding body is inserted and supported by a portion of the sensor. The method according to any one of claims 1 to 4, Brushless DC motor, characterized in that the heat radiation fin is formed on the outer peripheral surface of the stator molding body. The method according to any one of claims 1 to 4, An inlet is formed through the second housing in place, A blower duct is formed in the stator molding body so as to communicate with the inlet through one side from the other side of the stator molding body in the axial direction from the outside of the stator, A discharge port is formed in place of the first housing so as to communicate with the blowing duct, An air blower fixed to the rotor shaft extending outside of the second housing so that a blowing fan for blowing air to the inlet of the second housing is integrally rotated with the rotor; Brushless DC motor. The method according to any one of claims 1 to 4, The core of the stator is formed by connecting a plurality of core pieces, And the coils are insulated and wound around each of the core pieces. The method of claim 8, Each of the stator core pieces is inserted into a bobbin of a failure shape, And the coil is wound around the bobbin and insulated from each of the core pieces. The method according to any one of claims 1 to 4, The magnet of the rotor is surrounded by a cylindrical magnet ring, The magnet is a rotor of a motor, characterized in that molded by injecting a magnet resin in the space between the rotor shaft and the magnet ring. The method of claim 10, Brushless DC motor, characterized in that the projection or groove is formed on the inner peripheral surface of the magnet ring in contact with the magnet. The method of claim 10, Brushless DC motor, characterized in that the projection or groove is formed on the outer peripheral surface of the rotor shaft in contact with the magnet. The method according to any one of claims 1 to 4, An inlet is formed through the second housing in place, The stator molding body has a sensor support groove for supporting a part of the sensor is inserted into one side, a heat radiation fin is formed on the outer peripheral surface, the air duct is in the axial direction from the outside of the stator so as to communicate with the inlet It penetrates from one side of the molding to one side, A discharge port is formed in place of the first housing so as to communicate with the blowing duct, An air blower fixed to the rotor shaft extending outside of the second housing so that a blowing fan for blowing air to the inlet of the second housing is integrally rotated with the rotor; Brushless DC motor. The method of claim 13, The core of the stator is formed by connecting a plurality of core pieces, The coil is wound around each of the core pieces, The magnet of the rotor is surrounded by a cylindrical magnet ring, The magnet is a rotor of a motor, characterized in that molded by injecting a magnet resin in the space between the rotor shaft and the magnet ring.