KR20040002349A - Brushless Direct Current Motor of Radial Core Type Having a Structure of Double Rotors - Google Patents

Abstract

PURPOSE: A BLDC motor using a radial core type double rotor method is provided to increase the output and the torque and reduce a manufacturing cost by using separative stator cores. CONSTITUTION: A BLDC motor using a radial core type double rotor method includes a rotary shaft(52), an inside rotor(53) and an outside rotor(54), and an integrated stator(62). The rotate shaft(52) is rotatably installed at a stator support portion(50). The inside rotor(53) and the outside rotor(54) are installed at a center of a case. The inside rotor(53) and an outside rotor(54) include an inside yoke(55), an outside yoke(56), and a plurality of magnets(57c,58a,58c). The integrated stator(62) is installed between the inside rotor(53) and an outside rotor(54). The integrated stator(62) is formed with a coil assembly having separative cores(59a,59c) and coils(60a,60c) wound around the separative cores(59a,59c) and a stator support(61).

Description

Brushless Direct Current Motor of Radial Core Type Having a Structure of Double Rotors}

The present invention relates to a radial core type BLDC motor, and more particularly, to a magnetic circuit as an inner / outer rotor and each stator core by arranging the rotor in a radial core type BLDC motor in double and inside the stator. The present invention relates to a radial core type double rotor type BLDC motor that can achieve a complete division of the stator core to increase productivity and motor output.

When the BLDC motor is classified according to the presence of the stator core, it is generally divided into a core type (or radial type) and a coreless type (or axial type) having a cup (cylindrical) structure.

The core type BLDC motor has an inner magnet type of FIG. 2 consisting of a rotor composed of a cylindrical stator and a cylindrical permanent magnet wound with coils to have an electromagnet structure on a plurality of protrusions formed on the inner circumference, and a plurality of stators formed on the outer circumference. The coil is wound up and down in the up and down direction of the projection of and is classified into the external magnet type of FIG. 1 composed of a rotor made of a cylindrical permanent magnet magnetized outside.

In the case of the external magnet type, as shown in FIG. 1, a stator core 1a wound with a coil (not shown in the drawing) is installed as a stator on a base through a support, and a cup-shaped rotor 1c is provided as a center portion. It is installed through the rotating shaft (1d) in the free rotation through the bearing installed in the center of the stator, the permanent magnet (1b) is attached to the inner side of the rotor in a circular shape, the predetermined gap, that is, the gap (G) with respect to the stator Formed.

When power is applied, a magnetic field is formed in the coil wound around the stator core 1a of the stator, and the rotor case rotates by the interaction with the magnetic flux by the permanent magnet 1b installed in the rotor 1c.

The main path of the magnetic flux in the conventional BLDC motor as described above proceeds in the permanent magnet of the rotor and forms a magnetic circuit that travels in the direction of the permanent magnet and the yoke again through the stator of the stator through the gap.

In the case of the inner magnet type, as shown in Fig. 2, a plurality of "T-shaped" core portions 2c of the stator core 2a on which the coil is wound are formed to protrude from the outside inward, and the inner end of each core portion is formed. The rotor forms a circle of constant diameter, and a rotor 2f having a ring-shaped permanent magnet 2b attached to a cylindrical permanent magnet including a rotating shaft 2d in a space therein or a cylindrical yoke 2e including a rotating shaft in a center thereof. Is mounted. The method of rotating the motor is the same as the external magnet type.

Since the core type BLDC motor has a structure in which the magnetic circuit is symmetrical in the radial direction about the axis, there is little vibrational noise in the axial direction, suitable for low speed rotation, and extremely small portion of the air gap in the direction of the magnetic path. High magnetic flux density can be obtained even by using low magnet or reducing the amount of magnet, which has the advantage of high torque and high efficiency.

However, this yoke structure has a high material loss of yoke when manufacturing stator, and due to the complicated structure of yoke, it is necessary to use a special expensive winding machine for winding coils on yoke. It has a disadvantage of high facility investment cost due to high mold investment cost.

On the other hand, in order to improve the disadvantages of the core type BLDC motor described above, the conventional coreless BLDC motor proposed by the present applicant is an axial type axis generated when the rotor rotates through Patent Publication No. 99-213573 It is presented in the form of a double rotor that can cancel directional vibrations and increase torque by more than twice.

Detailed structure of the double rotor type BLDC motor is shown in Figs. 3a and 3b, the first and second rotor in which a plurality of magnets 3b are mounted on the annular first and second yokes 3k, 3l. 3d and 3e, a rotating shaft 3j coupled to the center of the first and second rotors 3d and 3e via a bushing, and first and second cases rotatably supporting the rotating shaft 3j. 3f and 3g and first and second bearings 3h and 3i mounted between the first and second cases 3f and 3g and the rotary shaft 3j so that the rotary shaft 3j can be rotated smoothly. And a stator 3a for preventing axial vibration with respect to the generation of the rotational driving force while generating the rotational driving force for the first and second rotors 3d and 3e.

The plurality of magnets 3b mounted on the first and second rotors 3d and 3e are disposed to have polarities opposite to each other with respect to adjacent magnets, and particularly constitute the first and second rotors 3d and 3e. The first and second yokes 3k and 3l are disposed to have polarities opposite to each other.

In addition, the stator 3a is provided with a predetermined gap between the first and second rotors 3d and 3e, and the first and second rotors 3d and 3e in response to an applied DC current. A plurality of bobbinless coils 3c are wound to apply electromagnetic force to them.

The coil 3c generates a magnetic flux having the same axial polarity direction when the corresponding magnets 3b of the first and second rotors 3d and 3e have opposite polarities, respectively, and the first and second The current is supplied to generate the electromagnetic force applied in the opposite directions to the two rotors 3d and 3e.

The conventional double rotor type BLDC motor has a structure in which a plurality of wound coils 3c are mounted on a PCB in the middle of the first and second rotors 3d and 3e, respectively. ) And a magnetic circuit having a symmetrical structure with respect to the rotation axis 3j.

With this structure, the stator coil is doubled and the field magnet is also doubled by the first and second rotors and the stator, and the driving current and the magnetic flux density are doubled. The result is at least two times more torque than the same axial single rotor structure.

The axial coreless motor has various advantages, but since the portion occupied by the armature winding is formed by the air gap, the magnetic flux density of the air gap is lower than that of the used magnet due to the high magnetic resistance.

In other words, in the magnetic circuit formed by the magnets m1 to m4 as shown in FIG. 6, the magnets are formed at the portion of the gap G formed between the magnet m1 and the magnet m2 and between the magnet m3 and the magnet m4. The motor's efficiency is lowered because the resistance increases so much that loss of magnetic flux occurs.

In addition, to increase the number of turns of the armature winding to realize a high torque motor, the air gap must be further increased, resulting in a decrease in the magnetic flux density, resulting in a further decrease in efficiency.

Therefore, the axial coreless motor has a feature of using a high-performance magnet or increasing the amount of the magnet compared to the radial core type of the equivalent output, and ultimately has a problem of raising the price of the product.

In order to overcome these problems, the applicant has proposed a motor in the form of an axial core as a patent application No. 2001-0087925 (Dec. 29, 2001).

Proposed through the axial core type is to introduce a magnetic core in the center of the armature stator in the existing axial gap type BLDC motor to reduce the magnetic resistance by reducing the gap spacing to minimize the magnetic resistance while increasing the magnetic efficiency It is to provide a BLDC motor that retains the advantages of the conventional axial gap type.

7A to 7C illustrate a structure of a BLDC motor of an axial core type double rotor type according to the above proposal.

BLDC motor according to the proposal is a rotating shaft 15 is rotatably mounted through the bearing (17, 18) in the upper and lower center of the case (10, 11) as shown in Figure 7b; First and second rotors 21 and 22 mounted on the rotary shaft 15 to rotate together; A plurality of magnets 27 and 28 mounted on the first and second rotors 21 and 22 with opposite polarities; A stator (30) installed between the first and second rotors (21, 22); A coil 35 wound around the stator 30; It is composed of a stator core 40 and the like, which are mounted at the core of the stator on which the coil is wound to form a magnetic circuit.

The plurality of magnets 27 and 28 are disposed to have polarities in opposite directions with respect to other adjacent magnets, and the first and second yokes 25 and 26 that constitute the first and second rotors 21 and 22. ) Should be arranged with polarities opposite to each other.

The core 40 is disposed at an air core of the stator 30 disposed between the first and second yokes 25 and 26, and a coil 35 is wound around the core 40.

As shown in FIG. 7C, the structure of the core 40 is formed by stacking silicon steel sheets to prevent magnetic flux loss due to eddy currents that may occur during rotation of the motor, or may have high permeability and high electrical permeability. Sintered soft magnetic compound is used. In this case, the shape of the core can be made more free.

However, it is true that an axial gap type motor with or without such a core has many of the advantages listed above, but is inevitably disadvantageous over a radial type motor in terms of axial vibration. In particular, the axial type motor with the core has the attraction force in the opposite direction between the stator core and the permanent magnets on both sides of the stator core. It also has the weakness of being unstable.

On the other hand, a motor having an internal / external double rotor structure has been proposed by improving its own structure of a radial core type motor (Patent Publication No. 93-22682). However, the purpose of the prior art is merely to increase the amount of permanent magnets and to increase the output of the motor by utilizing the empty space, and the stator core still has an integrated structure, which is a problem of material loss and expensive. It has the same problem as the investment cost of the winding machine and the problem that the winding must be doubled inside and outside of the stator core.

In addition, the winding equipment for the winding inside the core and the winding equipment for the winding outside the core cannot be shared, so the investment cost for the winding machine increases as the output of the motor increases.

In addition to the prior art described above, in the radial core type motor, a plurality of split core structures have been proposed in order to reduce the productivity of the coil winding of the stator and the equipment investment cost for the winding machine.

Accordingly, the present invention has been made in view of the problems of the prior art, and its object is to provide a permanent magnet rotor and rotor yoke inside and outside by arranging the permanent magnet rotor simultaneously inside and outside the stator core. It is possible to provide a BLDC motor of a radial core type double rotor type that can be completely divided by staging cores, which can greatly increase the productivity of the stator core and the output of the motor by means of individual coil windings.

It is another object of the present invention to provide a radial core type double rotor type BLDC motor that can utilize the advantages of the axial double rotor type and the radial core type and improve the disadvantages.

1 is a cross-sectional view for explaining the structure of a conventional external magnetic core type BLDC motor;

2 is a cross-sectional view for explaining the structure of a conventional internal magnet type core type BLDC motor;

3A and 3B are a plan view and a sectional view for explaining the structure of a conventional double rotor type coreless BLDC motor;

4A to 4C are explanatory diagrams for explaining a toroidal permanent magnet having voids;

5 is an explanatory diagram for explaining a conventional magnetic circuit;

6 is an explanatory diagram for explaining a conventional axial gap type magnetic circuit;

7A to 7C are schematic plan views, axial cross-sectional views, and a perspective view of a core for explaining the structure of an axial core type dual rotor type BLDC motor, respectively;

8 is an explanatory diagram for explaining a magnetic circuit of a radial core type double rotor type BLDC motor according to the present invention;

9A to 9D are circumferential cross-sectional views, axial plan views, a perspective view of a divided stator core and a perspective view of a bobbin for explaining the structure of the radial core type double rotor method according to the present invention;

10A and 10B are plan views for comparing a magnetic circuit according to the present invention with a conventional external magnetic radial core type motor;

11 is a plan view showing the core arrangement in the case of taking the shape of the divided core according to the second embodiment of the present invention in the T-shape,

It is a perspective view explaining the assembling process of a T-shaped core and a bobbin.

* Description of symbols on the main parts of the drawings *

50; Stator support 51; bearing

52; Axis of rotation53,54; Inner / outer rotor

55,56; Inner / outer yoke 57a-57d, 58a-58d; magnet

59,59a-59f; Core 60,60a-60d; coil

61; Stator support 62; Stator

63,63a, 63b; Bobbins 159a-159h; core

In order to achieve the above object, the present invention includes a rotating shaft rotatably mounted on the stator support; A plurality of magnets rotatably mounted to the center of the case through the rotation shaft and mounted to the inner side of the inner yoke and the cup-shaped outer yoke and the inner surface of the outer and outer yokes of the inner yoke and opposed to each other in opposite polarities; An inner and outer rotor including; It is installed with a gap between the inner and outer rotor, characterized in that composed of an integral stator formed by the stator support a plurality of coil assemblies wound around a plurality of coils through a bobbin on each of the plurality of split cores A radial core type double rotor type BLDC motor is provided.

In the present invention, the center of the case is rotatably mounted through a rotating shaft, the inner yoke and the outer yoke are supported on the rotating shaft, and a plurality of or multi-pole opposing magnets are mounted on opposing surfaces of the inner and outer yokes, and the radial double rotor To form.

In addition, an annular stator is formed between the opposing magnets of the double rotor at a predetermined gap, and the stator includes a plurality of split stator cores, and coils are individually wound around each split stator core. The plurality of split stator cores are fixed by a stator support made of resin injected around them to form a fixed annular shape.

The stator core is made of a magnetic material to concentrate the magnetic flux of the magnetic circuit formed by the magnets attached to the inner and outer yokes, and the core is made of a plurality of silicon steel sheets or has excellent magnetic properties and high electrical resistance. Sintered soft magnetic compound material is used.

In the radial core type double rotor type BLDC motor, a magnetic path is formed through an inner and outer rotor and a plurality of stator cores disposed with a gap between the inner rotor and the outer rotor, thereby enabling complete division of the core. do.

On the other hand, the manufacturing method of the motor according to the present invention comprises the steps of molding a plurality of divided core of the "T" shape using a magnetic material; Winding a coil on an insulating bobbin that can cover the outer periphery of the core; Preparing a plurality of split core assemblies having coils wound thereon by inserting a pair of cores having a “T” shape in both directions of the bobbin and bonding the two portions by caulking to the coiled bobbins; Arranging and fixing a plurality of split core assemblies having the coils wound on a printed circuit board (PCB), connecting the coils, and forming a reduced shape by insert molding using a thermosetting resin to prepare an integrated stator; ; And assembling the unitary stator to be located between the radial double rotors.

According to another aspect of the present invention, there is provided a method of manufacturing a motor, comprising: forming a plurality of split cores having a “T” shape using a magnetic material; Winding a coil around each of the plurality of insulated bobbins that can cover the outer periphery of the core; Preparing a plurality of split core assemblies having coils wound by inserting cores having a “T” shape in each of the plurality of bobbins wound with coils; Arranging and fixing a plurality of split core assemblies having the coils wound on a printed circuit board (PCB), connecting the coils, and forming a reduced shape by insert molding using a thermosetting resin to prepare an integrated stator; ; And assembling the unitary stator to be located between the radial double rotors.

According to still another aspect of the present invention, there is provided a method of manufacturing a motor, comprising: forming a plurality of split cores having an “I” shape by using a magnetic material; Forming upper and lower insulating bobbins divided up and down to cover the outer periphery of the core; Preparing a plurality of split core assemblies in which coils are wound by winding coils on the assembled bobbins while the upper and lower bobbins are assembled to the I-type core from above and below; Preparing a unitary stator by molding the plurality of split core assemblies having the coils wound into a reduced shape by insert molding using a thermosetting resin; And assembling the unitary stator to be located between the radial double rotors.

As described above, the present invention takes advantage of the double rotor axial type BLDC motor and provides a motor in which the stator core is completely divided. That is, the BLDC motor of the present invention saves the advantage of increasing the output and torque of the axial double rotor type, and eliminates the disadvantage of the high material cost due to the use of high performance magnetic materials, and the axial vibration of the radial core type motor. Radial core type double rotor type BLDC with divided core structure to take advantage of this small advantage and eliminate the disadvantages of expensive mold investment cost, coil winding cost, and equipment investment cost using dedicated winding machine. Provide a motor.

(Example)

Hereinafter, with reference to the accompanying drawings showing a preferred embodiment of the present invention described above in more detail.

The present invention focuses on the fact that the permanent magnet rotor is placed on both sides of the stator in the axial gap type dual rotor BLDC motor to increase the output and form a magnetic circuit. As a new motor of this combined type, a motor structure capable of realizing a split core structure is proposed.

Before describing the present invention, an ideal magnetic circuit will be described. As shown in FIG. 4A, when a toroidal magnet having a void lg is filled with a high permeability magnetic aid in the void lg, the state of the magnet may be considered to be a position on the potato curve of FIG. 4C. This state is the highest magnetic flux density (Bm) in the absence of an external magnetic field, and can be said to have the lowest magnetic resistance.

In this state, if the auxiliary of the void is removed, the magnetic permeability (reluctance) of the magnetic circuit increases because the permeability of the air is lower than that of the auxiliary, and the state of the magnet moves to point b on the potato curve of FIG. 4C. That is, the magnetic flux density Bm decreases.

Except for the presence of voids, the magnetic flux will be distributed only within the magnet and will be uniformly distributed in the cross section of the magnet. In the air gap there is a slight spreading phenomenon in the magnetic flux distribution as in FIG. 4B, so the cross-sectional area Ag of the air gap should be considered to be slightly larger than the cross-sectional area Am of the magnet.

The application of the ampere integration law for the magnetic field results in Equation 1 because there is no free current.

It can be seen from Equation 2 that the presence of voids causes an effect such as applying a magnetic field (magnetic field) opposite to the direction of magnetic flux propagation inside the permanent magnet (H _m and H _g Opposition).

Since the magnetic flux must be continuous throughout the circuit, it is established as in Equation 3, and the relationship between the magnetic flux density in the gap and the magnetic field is the same as in Equation 4. Thus, Equation 5 is obtained by Equation 1 to Equation 4. Can be.

Here, μ ₀ is the permeability of vacuum or air and has a value of 4π × 10 ⁻⁷ [N / A ² ] or 4π × 10 ⁻⁷ [H / m] in the SI unit system, and magnetic field and magnetic flux density distributed in space. Coefficient representing the relationship between. Ferromagnetic materials such as iron sometimes have a magnetic permeability of about 5000 μ ₀ . The magnetoresistance R _m can be expressed as l / μS, where l is the length of the magnetic circuit through which the magnetic flux passes and S is the cross-sectional area. In this equation, the permeability is inversely proportional to the magnetoresistance.

Equation 5 is a formula representing the straight line (0, b) of Figure 4c, the intersection of the potato curve b represents the magnetic state (operation point) in the state of removing the auxiliary. The value representing the slope of such a straight line is called a permission coefficient.

The analysis shows that the operating point of the permanent magnet with voids is determined by the shape of the magnet and the potato curve. However, since it is far from the actual situation, a more realistic situation as shown in FIG. 5 can be considered.

The magnet 5a occupies only a part of the magnetic circuit, and most of the magnetic poles have a low magnetic resistance and a high permeability, and have pores in which the magnetic aid 5b is inserted. have. Therefore, as for the total magnetic flux φm generated by the magnet 5a, most of the magnetic flux φg passes through the pole piece 5c as before. If the magnetic aid 5b is removed, some magnetic flux will leak and pass through the space between the upper and lower pole pieces 5c as indicated by? In FIG. In order to indicate this situation, the leakage coefficient q should be included as shown in Equation 6 below.

Q is defined as (magnetic flux in the magnet) / (magnetic flux in the void), and the relationship between B _m and H _m is defined as in Equation (7).

In the above description, the following facts can be seen.

1. The state (operating point) of a permanent magnet is determined by the demagnetization characteristics, the size of the magnet, and the configuration of the magnetic circuit.

2. The magnetic flux density at the operating point increases if the magnets are the same in the same direction, and the smaller the area of the plane perpendicular to the magnetization direction is.

3. The magnetic flux density decreases when there is a part of the magnetic circuit with a large magnetic resistance such as a void. The longer the pore length, the lower the magnetic flux density.

4. The greater the magnetic resistance of the magnetic circuit, the lower the magnetic flux density, the larger the magnetic field (H _m , potato) in the opposite direction to the magnetic flux inside the magnet.

Therefore, in the present invention, as in the conventional axial gap type double rotor BLDC motor, the permanent magnet rotor is disposed inside / outside of the stator to form a magnetic circuit instead of forming a magnetic circuit. It provides a BLDC motor with the advantages of low material loss.

9A to 9C are cross-sectional views, a plan view, and a perspective view of a single stator core for explaining the structure of a double rotor type BLDC motor according to the present invention, and FIGS. 10A and 10B show a conventional magnetic circuit of the present invention. It is explanatory drawing for comparing with a radial type.

9A to 9C, the radial core type double rotor type BLDC motor according to the present invention includes a rotating shaft 52 rotatably supported at the center of the case through two bearings 51 on the stator support 50. A pair of double rotors (53, 54) consisting of an inner rotor (53) and an outer rotor (54) are coupled to each other in a radial structure, and an annular core stator (62) is disposed between the double rotors (53, 54). It is.

The double rotors 53 and 54 preferably have an inner yoke 55 having a cylindrical shape and an outer yoke 56 having a cup shape and are integrally formed to be supported by the rotation shaft 52, and the inner yoke 55 is provided. The opposing surfaces of the outer yoke 56 and the plurality of magnets 57a-57d and 58a-58d are separately magnetized or mounted with a plurality of magnets. In addition, the plurality of opposing magnets located on the opposing surfaces of the inner yoke 55 and the outer yoke 56 are arranged to have opposite polarities, and at the same time, they are disposed to have opposite polarities with respect to other adjacent magnets.

Further, in the annularly arranged stator 62 having a predetermined gap between the opposing magnets of the double rotor, a plurality of split stator cores 59: 59a-59d are disposed, and each split stator core ( The coils 60: 60a-60d are individually wound to 59a-59d, and the plurality of split stator cores 59a-59d are formed of stator supports made of resin injected around them to form a fixed annular shape. 61).

The structure of the split cores 59a-59d is formed by stacking a plurality of silicon steel sheets in order to prevent a loss of magnetic flux due to eddy currents that may occur when the motor rotates, as shown in FIG. 9C. In addition, sintered soft magnetic compounds having high permeability and high electrical resistance are used. In this case, the shape of the core can be made more free.

Before explaining the operation of the present invention configured as described above with reference to Figure 10b will be described a magnetic circuit for the external magnet type of the conventional radial core type motor (Fig. 1). In the motor having the integral core structure, when power is applied to the coil, a magnetic field is formed on the coil wound around the stator core 1a of the stator, and thus the interaction with the magnetic flux by the permanent magnet 1b installed on the rotor 1c. The rotor case rotates by this.

In this case, the motor of the integral core type has a magnetoresistance to maintain the flow of the magnetic path along the arrow direction A1 formed to pass through the integrated stator core 1a, the magnet 1b of the rotor and the yoke as shown. The lower core portion of the salient pole and the salient pole 1e should be connected to each other and formed integrally.

Therefore, such an integral core type motor is difficult to be competitive because the work of winding the coil in the "T" type core part is carried out using a dedicated winding machine and the manufacturing cost and equipment cost become high. In addition, the conventional radial integral core type motor has a high material loss rate and a difficult winding because of its complex and large core shape.

On the other hand, in the present invention having a split core structure, as shown in Fig. 10A, the magnet 57a, the inner yoke 55, the magnet 57b, the stator core 59b, and the outer rotor 54 of the inner rotor 53 are shown. One magnetic circuit is formed along the arrow direction A10 composed of the magnet 58b, the outer yoke 56, the magnet 59a and the stator core 59a of the "

That is, in the structure proposed by the present invention, since the permanent magnets 57a-57d and the yoke 55 of the inner rotor 53 take the role of the salient pole in the conventional integrated core, the stator core 59 may be integrated. no need. Therefore, in the present invention, it is possible to manufacture the stator core into a plurality of individual cores 59a-59d.

As a result, since the split core is small in size, the waste rate of the silicon steel sheet is small, so that there is almost no material loss, the shape is simplified, and the manufacturing is easy, and the winding for the split cores 59a-59d is made using a general-purpose winding machine. Winding becomes possible, which reduces the cost of coil winding and the investment in winding equipment.

Stator manufacturing method of the present invention is first formed using a steel sheet made of silicon steel (silicon steel) material as shown in Figure 9c, respectively, and then formed into a core (59) of "I" shape, and then separated it up and down 2 "T" shape The cores 59e and 59f are laminated, or the soft magnetic powder sintered product is manufactured up and down separately to prepare a split core 59.

After that, the coil is first wound on the insulator bobbin 63 as shown in FIG. 9D by a general transformer manufacturing method, and then, a part of the T-shaped core 59e separated in the bobbin 63 is first inserted, and the opposite direction is obtained. The remaining T-shaped core portion 59f is inserted into the two portions by the caulking to complete the split core assembly on which the coil is wound. Subsequently, a thermosetting resin is formed by injection molding by insert molding in a state in which a plurality of coils are wound and arranged in a printed circuit board (PCB) by arranging and fixing the divided core assemblies. When the injection molding is performed in a reduced shape, the integrated stator of the present invention is completed.

Another stator manufacturing method according to the second embodiment of the present invention will be described below with reference to FIGS. 11 and 12.

First, the split cores 159a-159h are manufactured in a T-shape, and then coils 60a-60d are respectively wound around the plurality of insulator bobbins 63 as shown in FIG. 9D, and then each bobbin 63 is wound. T-shaped cores 159a, 159c, 159e, and 159g separated from each other are inserted in the upper direction as shown in FIG. 12, or T-shaped cores 159b, 159d, 159f, and 159h are inserted into the bobbin 63 from the lower direction, respectively. Multiple coils complete the wound core assembly.

Subsequently, as in the first embodiment, the split core assembly having a plurality of coils wound is arranged and fixed on a printed circuit board (PCB), the coils are connected, and then the insert molding is performed in a state in which the coil is reduced in a mold not shown. When the thermosetting resin is injected into a reduced shape by injection molding, the integrated stator of the present invention similar to the first embodiment is completed.

The stator cores 159a-159h illustrated in FIG. 11 omit the illustration of the bobbin 63, the coil 60 wound thereon, and the stator support 61 formed of a resin in order to show the core structure well.

Another stator manufacturing method according to the third embodiment is to fabricate the " I " type integral core as shown in FIG. 9C, and then, the upper and lower divided bobbins 63a and 63b shown in FIG. The coil 60 is wound around the assembled bobbin in an assembled state from above and below to prepare a plurality of split core assemblies in which the coil is wound.

Subsequently, injection by insert molding in a state in which a plurality of split core assemblies wound with coils are arranged and fixed on a printed circuit board (PCB) in the same manner as in the above embodiment, and then connected to a mold not shown in the figure. When the thermosetting resin is injected into the molding method and manufactured into a reduced shape, the integrated stator of the present invention similar to the first embodiment is completed.

Although the bobbins used in the first to third embodiments exemplify structures divided from each other, a plurality of bobbins may have a structure in which both ends are connected to each other in a reduced form.

Thereafter, when the rotary shaft 52 and the integrated double rotors 53 and 54 are coupled to the integrated stator 62 completed as described above, a BLDC motor of a radial core type double rotor type having a divided core structure is completed.

As described above, the BLDC motor of the present invention provides a motor in which the stator core is completely divided, thereby increasing the output and torque of the axial double rotor type, and using the high-performance magnetic material. Eliminates the disadvantages of the coil winding cost of using the integrated stator core and the equipment investment cost of using a dedicated winding machine.

In the above, the present invention has been illustrated and described with reference to specific preferred embodiments, but the present invention is not limited to the above-described embodiments, and the general knowledge in the technical field to which the present invention pertains does not fall within the spirit of the present invention. Various changes and modifications will be made by those who possess.

Claims (11)

A rotating shaft rotatably mounted to the stator support; A plurality of magnets rotatably mounted to the center of the case through the rotation shaft and mounted to the inner side of the inner yoke and the cup-shaped outer yoke and the inner surface of the outer and outer yokes of the inner yoke and opposed to each other in opposite polarities; An inner and outer rotor including; It is installed with a gap between the inner and outer rotor, characterized in that composed of an integral stator formed by the stator support a plurality of coil assemblies wound around a plurality of coils through a bobbin on each of the plurality of split cores Radial core type double rotor type BLDC motor. The method of claim 1, wherein the unitary stator is Multiple split cores, A plurality of insulating bobbins surrounding the plurality of split cores, A plurality of coils wound around an outer periphery of each of the plurality of bobbins, Radial core type double rotor type BLDC motor, characterized in that consisting of a reduced stator support for supporting a plurality of split core assembly coiled in the bobbin at regular intervals. The radial core type double rotor type BLDC motor according to claim 1 or 2, wherein the plurality of split cores each have an "I" shape. The radial core type double rotor type BLDC motor according to claim 1 or 2, wherein the plurality of split cores each have a "T" shape. A radial core type double rotor type BLDC motor according to claim 1, wherein a magnetic path is formed through a plurality of stator cores disposed with a gap between the inner and outer rotors and the inner rotor and outer rotors. Molding a plurality of split cores having a “T” shape using a magnetic material; Winding a coil on an insulating bobbin that can cover the outer periphery of the core; Preparing a plurality of split core assemblies having coils wound thereon by inserting a pair of cores having a “T” shape in both directions of the bobbin and bonding the two portions by caulking to the coiled bobbins; Arranging and fixing a plurality of split core assemblies having the coils wound on a printed circuit board (PCB), connecting the coils, and forming a reduced shape by insert molding using a thermosetting resin to prepare an integrated stator; ; And a step of assembling the integrated stator to be located between the radial double rotors. Molding a plurality of split cores having a “T” shape using a magnetic material; Winding a coil around each of the plurality of insulated bobbins that can cover the outer periphery of the core; Preparing a plurality of split core assemblies having coils wound by inserting cores having a “T” shape in each of the plurality of bobbins wound with coils; Arranging and fixing a plurality of split core assemblies having the coils wound on a printed circuit board (PCB), connecting the coils, and forming a reduced shape by insert molding using a thermosetting resin to prepare an integrated stator; ; And a step of assembling the integrated stator to be located between the radial double rotors. Molding a plurality of divided cores having an “I” shape using a magnetic material; Forming upper and lower insulating bobbins divided up and down to cover the outer periphery of the core; Preparing a plurality of split core assemblies in which coils are wound by winding coils on the assembled bobbins while the upper and lower bobbins are assembled to the I-type core from above and below; Preparing a unitary stator by molding the plurality of split core assemblies having the coils wound into a reduced shape by insert molding using a thermosetting resin; And a step of assembling the integrated stator to be located between the radial double rotors. The method of claim 6, wherein the forming of the plurality of split cores having a “T” shape comprises: forming a plurality of split cores having an “I” shape using a magnetic material; The method of manufacturing a radial core type double rotor type BLDC motor, comprising: dividing the plurality of split cores having an "I" shape up and down and cutting them into a pair of cores having a "T" shape. The method of manufacturing a radial core type double rotor type BLDC motor according to any one of claims 6 to 8, wherein the plurality of insulating bobbins are connected to each other. The radial core type double rotor method according to any one of claims 6 to 8, wherein the split core is formed by sintering a soft magnetic compound having a high permeability and a high electric resistance. Method for manufacturing BLDC motor