ES2363665T3 - CONTINUOUS CURRENT MOTOR WITHOUT RADIAL CORE BRUSHES THAT HAS A STRUCTURE OF DOUBLE ROTORS AND METHOD TO MANUFACTURE THE SAME. - Google Patents

Abstract

Brushless DC motor (BLDC) having a double-rotor radial core structure, comprising the BLDC motor: a rotating shaft (9) adapted to be rotatably mounted in a housing (2) of an apparatus in which it can the motor (1) BLDC, a double rotor (5) including an internal rotor (5a) and an external rotor (5b), being mounted, combining the central parts of the internal rotor (5a) and the external rotor (5b) with the shaft (9) rotating by means of a bearing (7) for the rotating support, a plurality of magnets (6a, 6b) of pole N and pole S being arranged alternately in annular form in the internal and external rotor (5a, 5b), respectively, so that the annular shape of the magnets in the internal rotor is concentric to the annular shape of the magnets in the external rotor and the magnets (6a) in the internal rotor (5a) have a predetermined distance and a polarity different from that of the corresponding opposite magnets (6b) in the external rotor (5b) , and an annular stator (3) adapted to be fixed to the housing (2) and installed between the internal and external rotors (5a, 5b), the stator (3) comprising several sets (3c '') of different stator cores, comprising each a stator core (3a, 3a ') and a coil (3b), a magnetic circuit that is formed by opposite magnets in the internal and external rotors (5a, 5b) that have different polarities and the cores (3a; 3a ') of separate stator located between the internal rotor (5a) and the external rotor (5b), characterized in that each set (3c' ') of stator cores comprises an insulation reel (30) having flanges (30a, 30b ) internal and external and surrounding a corresponding stator core (3a; 3a '), the coil (3b) is wound around the outer circumference of the reel (30), an annular core support plate (4' ') houses and supports the sets (3c '') of stator cores on a surface thereof with a predetermined interval between them, first and second projections (30c, 30d) of coupling extend from the bottom of the flanges (30a, 30b ) internal and external, respectively, of the insulation reels (30), and several first and second holes (47c, 47d) are formed in the ring core support plate (4 '') into which the first and second outgoing (30c, 30d) coupling so that the assemblies (3c '') of stator cores are placed on the annular support plate in radial and circumferential direction, and a stator support (3e) is formed between the annular core support plate (4 '') and the various assemblies (3c '') of stator cores by insert molding with thermosetting resin in order to integrate the sets (3c '') of stator cores into the ring core support plate (4 '') in a single body of annular shape, and an extension part (40a) extends inwardly from the core support plate (4 '') and is adapted to engage with the housing (2) of the apparatus.

Description

Technical sector

The present invention relates to a brushless DC motor (BLDC) having a radial core double rotor structure according to the preamble of claim 1.

State of the art

A BLDC motor can be classified as a core (or radial) and without a core (or axial), each having a generally cup-like structure (cylindrical), depending on whether or not there is a stator core.

A BLDC motor of a core structure is classified as an internal magnet of Figure 2 which includes a cylindrical stator in which coils are wound in several projections formed in the internal circumferential part thereof in order to form an electronic magnet structure , and a rotor formed of a cylindrical permanent magnet, and in an external magnet of Figure 1 that includes a stator in which coils are wound up and down in several projections formed in the outer circumferential part thereof, and a rotor formed of a permanent cylindrical magnet in whose external part are magnetized multiple poles.

In the external magnet BLDC motor as shown in Figure 1, stator cores (101a) are installed around which coils (not shown) are wound at the base of a stator through a support element, respectively . A cup-shaped rotor (101c) is installed through a central rotating shaft (101d), in which the rotor (101c) is freely rotated through a support installed in the center of the stator, and a magnet ( 101b) cylindrical permanent is attached to the internal circumferential part of the rotor, to form a predetermined fissure, that is, an air gap (G) with respect to the stator.

When power is applied to the motor of Figure 1, a magnetic field is created around the coils wound in the stator cores (101a) of the stator. Accordingly, the permanent magnet (101b) mounted on the rotor (101c) rotates a rotor cover by mutual action with a magnetic flux.

In the conventional BLDC motor, a main magnetic flux path is a magnetic circuit that forms a closed circuit that starts from the permanent magnet and continues to the permanent magnet again and a cylinder head through the air gap and the stator core of the stator.

In the internal magnet BLDC motor as shown in Figure 2, a plurality of T-shaped core parts (202c) in a stator core around which coils are wound, protrude inwards. In addition, the inner sides of the respective core parts form a cylinder of a predetermined diameter. In addition, a rotor (202f) having a cylindrical permanent magnet that includes a rotating shaft (202d), or a permanent ring-shaped magnet (202b) attached to a cylindrical cylinder head (202) that includes a central rotating shaft, is mounted in the inner part of the cylinder surrounded by the core parts (202c). The BLDC internal magnet motor rotates in the same way as the external magnet BLDC motor.

The magnetic circuit in the BLDC core motor described above has a symmetrical structure in the radial direction around the rotating shaft. Consequently, the BLDC core motor has less axial vibration noise, and is suitable for low speed rotation. In addition, since a part occupied by an air gap with respect to the direction of the magnetic path is extremely small, a high magnetic flux density can be obtained even if a low performance magnet is used or the number of magnets is reduced. As a result, great torque and high efficiency can be obtained.

However, such a cylinder head structure causes the loss of cylinder head material when the stator is manufactured. In addition, an exclusive, expensive, specialized winding machine must be used to wind the coils around the cylinder head during mass production, because the cylinder head structure is complicated. In addition, since a mold for manufacturing a stator is expensive, the initial investment costs are high.

Meanwhile, in order to improve the defects of the core BLDC motor described above, a conventional coreless BLDC motor proposed by the same applicant as that of the present invention is disclosed in U.S. Patent No. 5,945,766, as an axial type that is a double rotor BLDC motor to compensate for the axial vibration generated when the rotors rotate and that simultaneously increases the motor torque more than twice.

Between the first and second rotors, a stator is installed in the BLDC motor without the previous conventional core at a distance of a predetermined air gap with respect to the first and second rotors. A plurality of reels without reels are wound around the stator to apply an electromagnetic force to the first and second rotors in response to an applied DC current. In addition, current is applied to the coils so that magnetic fluxes having identical axial polarities are generated when the magnets corresponding to the first and second rotors have opposite polarities, and current is applied to the first and second rotors so that forces are generated electromagnetic in opposite directions to each other.

In the case of the BLDC double axial rotor motor, a stator is arranged in the middle of the first and second rotors, so that a magnetic circuit of a symmetrical structure with respect to the stator and the rotating shaft is formed. Therefore, due to the first and second rotors and the stator, the number of stator coils is increased twice and the number of field magnets is also increased twice with respect to a single rotor structure. Therefore, the drive current and the magnetic flux density are increased twice. As a result, the BLDC axial double rotor motor can obtain a torque of at least twice that of an identical structure of a single axial rotor.

The axial coreless motor has several types of advantages. However, since a part occupied by windings of the armature includes an air gap, the magnetic resistance is high and therefore, the magnetic flux density is low compared to the number of magnets.

In other words, in the case of a magnetic circuit formed by magnets m1 to m4 as shown in Figure 3, the magnetic resistance is greatly increased in an air gap G formed between the magnets m1 and m2 and between the magnets m3 and m4, and therefore, a loss of magnetic flux occurs. As a result, the efficiency of the engine decreases.

In addition, it requires that an air gap be made wider in order to increase the number of turns of the armature windings to implement a high torque motor. For this reason, the magnetic flux density would decrease considerably, and therefore the engine efficiency would be further decreased.

Therefore, the motor without axial core must use higher performance magnets and a larger number of magnets, compared to a radial core motor of equivalent power, and finally production costs can be raised.

However, although the air gap motor without axial core has the various types of advantages described above, it is in a more disadvantageous position than the radial motor, in view of axial vibration.

Meanwhile, in the case of a radial core motor, a specialized exclusive winding machine must be used to wind the coils around the integrated stator core described above. Consequently, several proposals have been made in order to solve the problems that the initial investment cost is very high and that the winding productivity of the coils around the stator core is low.

For example, in order to separate the internal / external wheels that form a core in an internal magnet core motor, the stator structure has been altered from a type of integration to a type of division, thus facilitating the winding of the coils, or the method of winding coils for cores has been altered without changing the integration core structure, thus improving the ease of work on the winding of the coils.

Meanwhile, an internal / external double rotor motor for a radial core motor has been proposed. However, this motor has only proposed to simply increase the number of permanent magnets and use an empty space, to thereby improve the motor performance, and the stator structure still has an integration structure. Therefore, there are still problems of poor workability of winding the coils, high material loss, high investment cost for the winding machine, etc., and the winding windings must be provided double-sided internal / external stator core.

In addition, a winding machine cannot be commonly used to wind coils on the inner side of the core and to wind coils on the outer side of the core. As a result, the investment cost for winding machines increases more than engine performance increases.

In addition to the conventional technique described above, a plurality of split core structure motors for a radial core motor have been proposed, in order to increase the winding productivity of the stator core coils and reduce the investment cost. For winding machines.

JP 7 143 710 discloses an electric motor in which an attractive force and a repulsive force are generated to act between both poles of an electromagnet and a permanent magnet. One pole of an electromagnet is oriented towards permanent magnets that are arranged in the circumference of a rotor, and the other pole is oriented towards a permanent magnet disposed on a side opposite the rotor by inserting the electromagnet so that it corresponds to the permanent magnets arranged in the circumference of the rotor. When the rotor rotates, the permanent magnet arranged in a housing opposite the rotor does not rotate.

JP 2001 218 431 discloses an engine that has a compact structure and high torque. This is achieved by a first rotor fixed to a tree, a second rotor fixed to a tree by a frame, and a stator arranged between the first and second rotors, in which the stator has a first groove in which the first is housed coil for the first rotor, and a second slot in which the second coil for the second rotor is housed, and in which an insulation plate is inserted between the first slot and the second slot to avoid mutual interference.

Document EP 0 779 085 A1 discloses a drive for transport facilities that improves the starting characteristics of the facilities. This is achieved by providing a drive for transport facilities comprising a shaft with a stator and a rotor assembly that can rotate on the shaft to form an electric motor, and a flange. The drive has permanent magnets, coils with coils, and transducers. The rotor appears as concentric envelopes and is connected to the flange. The stator is interposed between the permanent magnets and carries the coils with the cores, said coils being connected peripherally to the stator and being arranged in a spaced relationship with respect to the permanent magnets. The coils are mounted in a winding that has two or more phases subdivided into phase zones belonging n coils to the same phase. The cores with the stator are subject to straps. The envelopes are composed of a soft magnetic material and are interconnected through a non-magnetic wall. The rotor is closed with a cover.

JP 11 341757 discloses an electric motor that can be used as an energy transmission device for a hybrid car in which the engine has a split-core stator double rotor structure. A unit core unit is formed by laminating a plurality of electromagnetic steel plates, an insulation layer is formed on the surface of the unit core unit, and the unit unit core laminated is secured by a fixing bolt. The unit core unit is mounted between support flanges using pins in the support flanges. The double rotor includes an internal rotor that has permanent magnets and an external rotor that has a coil wound between the grooves of the rotor core. The coil is not connected to an external power source. Therefore, the external rotor functions as an induction machine. The internal rotor is connected to an internal rotor shaft and the external rotor is connected to an external rotor shaft. The internal rotor is a BLDC motor of IPM (permanent internal magnet) in which permanent magnets are inserted into the rotor core radially.

Object of the invention

An object of the present invention is to provide a brushless direct current motor (BLDC) having a radial core double rotor structure in which permanent magnet rotors are arranged on the inner and outer sides of a stator core, respectively , to thus form a magnetic circuit by means of the permanent internal and external magnets and rotor cylinder heads and thereby allow a complete division of a stator core and thus greatly increase the productivity of the coil windings and the motor performance.

Another object of the present invention is to provide a brushless direct current motor (BLDC) having a radial core double rotor structure that can obtain most of the advantages of an axial double rotor and a radial core one and Improve their disadvantages.

Still another object of the present invention is to provide a brushless direct current motor (BLDC) having a radial core double rotor structure that can greatly improve the productivity of mounting a stator by means of a stator structure that can wind coils by placing and automatically fixing a plurality of stator core assemblies to a core support plate when a split stator core structure and double rotor is employed.

Still another object of the present invention is to provide a brushless direct current motor (BLDC) that has a radial core double rotor structure that has an integrated double rotor structure that can improve durability and reliability by solidary molding. of internal and external rotors and bearings by an insert molding method using thermosetting resin.

Still another object of the present invention is to provide a brushless direct current motor (BLDC) having a radial rotor double rotor structure adapted as a driving source of a drum for a washing machine that requires impermeability by solidary molding of a stator by an insert molding method using thermosetting resin and combining the stator together with the integrated double rotors.

A further object of the present invention is to provide a method of manufacturing a brushless direct current motor (BLDC) having a radial rotor double rotor structure. The foregoing objects are achieved by a brushless DC motor comprising the features according to claim 1. Preferred embodiments of the motor of the present invention are claimed in claims 2 to 7.

The present invention adopts the advantages of the double rotor BLDC motor, and therefore provides a motor in which a stator core is perfectly divided. That is, the BLDC motor according to the present invention adopts the advantages of increasing performance and torque and eliminates the disadvantages of increasing the cost of material caused by using the high performance magnetic material of the axial double rotor motor, and adopts the advantages of producing the small axial vibration and eliminates disadvantages such as the high inversion of expensive molds, the winding cost of the coil caused by using a single integrated stator core, and the investment cost of the installation caused by using an exclusive winding machine .

In addition, it is possible to automatically position and fix several sets of stator cores to a core support plate, to thereby easily wire each coil to each other and improve the assembly productivity of the stators. In addition, the double rotors and the bearing are molded jointly by a method of insert molding using thermosetting resin, to thereby improve durability and reliability.

In addition, the stator is molded jointly by the use of thermosetting resin, and then combined with the integrated double rotors, thereby providing an appropriate BLDC motor for driving a drum of a washing machine.

Description of the figures

The foregoing and other objects and advantages of the present invention will become more apparent by describing the preferred embodiments thereof in more detail with reference to the accompanying drawings in which:

Figure 1 is a cross-sectional view to explain the structure of a conventional external magnet core BLDC motor;

Figure 2 is a cross-sectional view to explain the structure of a conventional internal magnet core BLDC motor;

Figure 3 is a view for explaining a conventional axial air gap magnetic circuit;

Figures 4A to 4C are seen to explain a permanent toroidal magnet having an air gap;

Figure 5 is a view to explain a conventional magnetic circuit;

Figures 6A to 6D are seen to explain the structure and the principle of operation of a BLDC radial rotor double rotor motor according to a basic embodiment not covered by the invention, Figure 6A being a cross-sectional view schematically showing the motor BLDC cut along the circumferential direction, Figure 6B being a plan view showing the BLDC motor cut along the axial direction, Figure 6C being a perspective view showing a divided stator core, and being Figure 6D a perspective view showing a reel;

Figures 7A and 7B are plan views for comparing a magnetic circuit not covered by the invention with that of the existing external magnet radial core motor;

Figure 8 is a plan view showing an arrangement of cores when the shape of a dividing core is of a T-shape according to a variation not covered by the invention;

Figure 9A is a front view of a radial core double rotor BLDC motor not covered by the invention;

Figure 9B is a cross-sectional view taken along line A-A of Figure 9A;

Figure 9C is a cross-sectional view cut along the line B-B of Figure 9A;

Figure 10A is a perspective view of a perfect division stator core that is not used in the present invention;

Figure 10B is a cross-sectional view taken along line A-A of Figure 10A;

Figure 11A is an exploded perspective view showing a coupling relationship of a set of stator cores and a core support plate according to an embodiment not covered by the invention.

Figure 11B is a partially enlarged perspective view of a core support plate;

Figure 11C is an enlarged view showing a coupling state of the core support plate;

Figure 12A is a bottom view of the core support plate of Figure 11A;

5

fifteen

25

35

Four. Five

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Figure 12B is an enlarged view of part "A" in the core support plate of Figure 12A;

Figures 12C to 12F are cross-sectional views showing a mutual winding structure between the coils;

Figures 13A to 13D are views showing an embodiment not covered by the invention, in which Figure 13A is an exploded perspective view showing a coupling relationship of a stator core assembly and a support plate of core, Figure 13B is an enlarged perspective view of the core support plate, Figure 13C is an enlarged view showing a coupling state of the core support plate, and Figure 13D is a cross-sectional view cut along the line AA of the dividing stator core;

Figure 14A is an exploded perspective view showing a coupling ratio of a stator core assembly and a core support plate according to an embodiment of the present invention;

Figure 14B is an enlarged view showing a dividing stator core;

Figure 15 is a perspective view showing an integrated stator according to the present invention.

Detailed description of the invention

The present invention provides a motor structure that can realize a dividing core structure as a new motor of a double rotor structure in which an internal magnet type and an external magnet type are combined. When the permanent rotors are arranged on both sides of a stator in a BLDC motor with an axial air gap double rotor, performance is improved and a magnetic circuit is formed. The present invention applies the advantages of such an axial air gap double rotor BLDC engine to a radial core double rotor BLDC engine.

Before describing the BLDC radial core double rotor motor according to the present invention, an ideal magnetic circuit will be described. In Figure 4A, a toroidal magnet has a lg air gap. When the air gap lg is filled with an auxiliary magnetic material of high permeability, it is assumed that the state of the magnet is placed at a point "a" in a demagnetization curve of Figure 4C. This position is a point that has the highest magnetic flux density Bmat, the state in which the external magnetic field is not present, and a state that has the lowest magnetic resistance.

If the auxiliary magnetic material is removed from the air gap, a magnetic resistance (reluctance) of the magnetic circuit is increased since the air permeability is lower than that of the auxiliary magnetic material, and the state of the magnet moves towards a point "b" in the demagnetization curve of Figure 4C. That is, a magnetic flux density Bm is decreased.

The magnetic flux is only present in the magnet except for an air gap. The magnetic flux is evenly distributed in the cross section of the magnet. However, the magnetic flux is distributed with little dispersion in the air gap as shown in Figure 4B. Therefore, the cross-sectional area "Ag" of the air gap will be considered to be slightly larger than the cross-sectional area "Am" of the magnet.

When the Ampere integration law is applied to the magnetic field, the following equation 1 is obtained,

image 1

From equation 2 it can be seen that the presence of the air gap induces the effect that a magnetic field of a direction opposite to the direction of advance of the magnetic flux (i.e. a field of demagnetization) in the permanent magnet. In this case, the signs of Hm and Hg are opposite each other. Since the magnetic flux must be continuous throughout the entire circuit, the following equation 3 is established. In addition, the relationship between the magnetic flux density and the magnetic field in an air gap is expressed as equation 4. Therefore, equation 5 can be obtained by equations 1 to 4.

image2

image2

In this case, 0 indicates the vacuum or air permeability, and has a value of 4 X 10-7 [N / A2] or 4 X 10-7 [H / m] in the SI unit system, which It is a coefficient that represents the relationship between the magnetic field and the magnetic flux density distributed in space. The permeability of ferromagnetic materials such as iron

5 amounts to approximately 50000. The magnetic resistance Rm is expressed as l /  S in which l indicates the length of the magnetic circuit through which the magnetic flux passes,  indicates the permeability, and S indicates a cross-sectional area. In this case, it can be seen that the permeability is inversely proportional to the magnetic resistance.

Equation 5 represents a straight line (0, b) of Figure 4C, in which an intersection "b" with the demagnetization curve represents a magnetic state in which an auxiliary magnetic material has been removed (ie a point of operation). A value that represents the slope of the straight line is called the permeation coefficient. Through the above analysis, it can be seen that the operating point of a permanent magnet is

15 determined by the shape of a magnet and a demagnetization curve. However, since the real situation is far from being the ideal case, it can be considered a more realistic situation as shown in Figure 5.

The part occupied by a magnet (105a) in a magnetic circuit is very small. The trajectory through which most of the magnetic fluxes pass, that is, a pole piece is composed of a material of low magnetic resistance and high permeability. The magnetic circuit includes an air gap in which an auxiliary magnetic material (105b) is inserted. Therefore, most of the fluxes ( g) between the total magnetic flux ( m) generated by the magnet (105th) pass through the pole piece (105c). If the auxiliary magnetic material (105b) is removed, leaks occur in a small number of flows and do not pass through the air gap. As a result, as shown in Figure 5, leaking flows  1 pass through the space formed between the upper and lower pole pieces 105. To represent the situation with previous leaks, a leakage coefficient q such must be included

image3

The leakage coefficient q is defined as (flow in a magnet) / (flow in an air gap). The relationship between Bm and Hm is defined as equation 7.

image2

The following facts should be considered from the equations described above.

-The state of a permanent magnet is determined, that is, the operating point by means of a demagnetization characteristic that is an inherent characteristic of a magnet, the size of the magnet, and the

35 construction of a magnetic circuit. -If the other conditions are the same, the magnetic flux density at the operating point becomes greater when a magnet is magnetized in the longitudinal direction and the surface area perpendicular to the direction of magnetization becomes small. -When a part of high magnetic resistance is present in part of a magnetic circuit, the magnetic flux density decreases. When the length of an air gap is extended, the magnetic flux density decreases. -When the magnetic resistance in a magnetic circuit becomes larger, the magnetic flux density decreases, and the magnetic field Hm of the opposite direction with respect to the magnetic flux in the magnet called the demagnetization field becomes large.

Therefore, the present invention provides a BLDC motor that has advantages of easy manufacturing, easy winding, and low material loss, based on the principle described above, in which the BLDC motor is manufactured by dividing a stator core instead of forming a magnetic circuit providing permanent magnet rotors on the internal and external sides of a stator.

Hereinafter, first, the structure and principle of operation of an engine will be described, and manufacturing embodiments of a stator will be described. Next, the most preferable embodiment of a motor marketed according to the present invention, a stator structure and various manufacturing methods thereof will be described.

Figures 6A to 6C are views to explain the structure and the principle of operation of a BLDC radial-rotor double rotor motor, Figure 6A being a cross-sectional view schematically showing the BLDC motor, Figure 6B being a view in plan showing the BLDC motor, and figure 6C being a perspective view showing a single stator core. Figures 7A and 7B are plan views for comparing a magnetic circuit according to the present invention with that of the existing radial core motor.

Referring to Figures 6A to 6C, in a BLDC radial-rotor double rotor motor, a pair of double rotors (5) that include an internal rotor (5a) and an external rotor (5b) are combined with a support structure of a stator, for example, a rotating shaft (9) which is rotatably supported to the center of a housing through two supports preferably in the housing (2) in the motor body, and an integrated annular stator (3) is arranged between the double rotors (5).

An annular internal cylinder head structure (8a) and an annular external cylinder head structure (8b) are preferably formed jointly in the double rotors (5), and supported in the rotating shaft (9). Several magnets (16a-16d) and (17a-17d) are magnetized in a divided manner on the opposite surface of the internal cylinder head structure (8a) and the external cylinder head structure (8b), or several of the divided magnets are mounted on the same. Several of the opposite magnets (16a-16d) and (17a-17d) placed on the surface oriented towards the internal cylinder head structure (8a) and the external cylinder head structure (8b), are arranged to have different polarities. Simultaneously, adjacent opposite magnets are arranged to have different polarities.

In addition, a predetermined air gap is formed between the opposing magnets in the double rotors. Several cores (3a) (23a-23d) of dividing stator are arranged in the stator (3) arranged annularly. A coil (3b) (13a-13d) is individually wound around each core (23a-23d) of splitting stator. Several dividing stator cores (23a23d) are fixed by stator support materials (3e) that are injection molded in thermosetting resin to achieve a fixed annular shape.

As shown in Figure 6C, the splitting stator cores (23a-23d) are composed of several silicon steel plates by depositing a silicon steel plate over another, or sintering a soft magnetic compound that has high permeance and high electrical resistance, in order to avoid the loss of a magnetic flux due to eddy current that can occur during the rotation of an engine. In this case, the shape of the core can be performed more freely.

Before describing the function of the BLDC radial core double rotor motor having the structure described above, a magnetic circuit in an external magnet motor will be described between conventional radial core motors as shown in Figure 1 with reference to the figure 7B. When power is applied to the coils in a motor of an integrated core structure, a magnetic field is formed in the coils wound around a stator core (1a), so as to rotate the rotor housing by interacting with the magnetic flux generated from a permanent magnet (1b) installed in the rotor (1c).

In this case, in the case of the integrated core motor, as shown, a protruding pole and another protruding pole (1e) in a core part of low magnetic resistance, must be connected to each other and formed in a solidary manner, with the in order to maintain a flow of a magnetic path along the direction A1 of the arrow formed by crossing the integrated stator core 1a, the magnet (1b) and the cylinder head in the rotor.

Therefore, since the coils are wound around a T-shaped core part in the integrated core motor, using an exclusive winding machine, the manufacturing cost and the installation cost become high thereby lowering the competitiveness Also, since a core shape is complicated and large in the conventional integrated radial core motor, a large amount of material is lost and winding work becomes difficult.

Meanwhile, as shown in Figure 7A, a split core motor forms a magnetic circuit along the direction (A10) of the arrow in sequence with a magnet (16a), an internal cylinder head structure 8a, a magnet (16b), and a stator core (23b) in an internal rotor (5a), and a magnet (17b), an external cylinder head structure 8b, a magnet (17a), and a stator core (23a) in a external rotor (5b).

That is, since the permanent magnets (16a-16d) and the cylinder head structure (8a) in the internal rotor (5a) play a role of protruding poles in the integrated core motor, it is not necessary that the core (3a) Stator type is integrated. Therefore, the stator core can be manufactured with several individual cores (23a-23d).

As a result, since a dividing core is small, the loss of silicon steel plate is small. Therefore, since the loss of material for the dividing core is low, and the shape of the dividing core is simplified, it can be easily manufactured. In addition, since the coils can be wound around the cores (23a-23d) divided using a general winding machine, the investment cost for winding the coils and acquiring a winding machine is reduced.

As shown in Figure 6C, a stator manufacturing method includes the steps of molding an I-shaped stator core (3a) using a silicon steel plate, and separating the shaped stator core (3a) I molded into upper and lower parts until it is then stacked in two T-shaped cores (23e and 23f), or by separating a soft magnetic powder agglomerated product into upper and lower parts and manufacturing a dividing core (3a).

Then, as shown in Figure 6D, the coils are wound around an insulating reel (30) by a general transformer manufacturing method. Then, a separate part (23e) of a T-shaped core is inserted into one side of the spool (30) and the other part (23f) separated from the T-shaped core is inserted into the other side of the spool (30) . These two parts of the T-shaped core are joined by a caulking process, to complete a set of stator cores around which the coils are wound. Then, the stator core assemblies around which the coils have been wound are arranged and fixed on a PCB, and the coils are wired. Then, in the state of the PCB in which the stator core assemblies are arranged annularly in a mold (not shown), thermosetting resin is injected by an injection molding method such as an insert molding method , thereby obtaining an integrated annular stator according to the present invention. Another method of manufacturing a stator will be described below with reference to Figure 8.

First, T-shaped split stator cores (24a-24h) are manufactured. Then, as shown in Figure 6D, the coils (13a-13d) are wound around several insulating reels (30). Then, the T-shaped cores (24a, 24c, 24e and 24g) are inserted separately on the reels 30 from above, and the separate T-shaped cores (24b, 24d, 24f and 24h) are inserted into the reels ( 30) from below, thus completing a set of stator cores around which several coils have been wound.

Then, in the same manner as in the embodiment described above, the stator core assemblies around which several coils have been wound are arranged and fixed on a PCB or a core support and the coils are wired. Then, in the state of the PCB in which the stator core assemblies are arranged annularly in a mold (not shown), thermosetting resin is injected by an injection molding method such as an insert molding method , thereby obtaining an integrated annular stator similar to the embodiment described above according to the present invention.

In Figure 8, the reel (30), the coils (3b) wrapped around the reel (30), and the stator support (3e) formed of resin have been omitted in order to illustrate a core structure of the cores Stator (24a-24h).

Like still another method of manufacturing stator, an integrated I-shaped core is manufactured as shown in Figure 6C, and then the reel that has been divided into the upper and lower reels (30i and 30j) as shown in figure 6D. Then, the split reels (30i and 30j) are mounted on the I-shaped core (3a), and then the coils (3b) are wound around the assembled reels (30i and 30j), thereby preparing several sets of stator cores around which the coils have been wound.

Then, in the same manner as the embodiment described above, the stator core assemblies around which several coils have been wound are arranged and fixed on a PCB and the coils are wired. Then, in the state of the PCB in which the stator core assemblies are arranged annularly in a mold (not shown), thermosetting resin is injected by an injection molding method such as an insert molding method , thereby obtaining an integrated annular stator similar to the embodiment described above according to the present invention.

As described above, although it has been described that the reel applied in the embodiments described above has a divided structure, several reels can be annular in order to then make both ends thereof connected to each other.

Then, a rotating shaft (9) and double rotor (5) integrated with the integrated stator (3) completed are combined to thereby complete a BLDC radial rotor double rotor motor of a divided core structure.

Next, a commercialized BLDC engine will be described herein.

Figure 9A is a front view of a radial core double rotor BLDC motor. Figure 9B is a cross-sectional view taken along line A-A of Figure 9A. Figure 9C is a cross-sectional view cut along the line B-B of Figure 9A.

Referring to Figures 9A to 9C, the BLDC motor is installed in the lower part of a washing machine and has an appropriate structure to drive the washing machine drum in the left and right directions, but is not limited thereto. That is, in the case of the BLDC motor (1) shown in Figure 9C, the inner circumferential part of a core support plate (4) is supported in a housing (2) of the washing machine by a variety of coupling elements such as a bolt / nut. The BLDC motor 1 includes a stator (3) in which several fully divided stator cores (3a) are mounted annularly by winding the coils (3b) around the outer circumference of a reel (not shown), a rotor (5 ) of a double rotor structure in which several magnets (6a and 6b) are arranged annularly with a predetermined magnetic air gap in the internal and external circumferences of the stator (3) and an internal rotor (5a) and a rotor (5b ) external are supported in a cylinder head structure (8), and a rotating shaft (9) that is rotatably supported in the housing (2) by means of a support (11) and connected to the center of the cylinder head structure (8) through a support (7).

The stator (3) is formed in a solidary manner by annular thermosetting resin by an insert molding method, in the state of temporarily assembling several sets (3c) of stator cores of Figure 11C by winding the coils (3b) around of the outer circumference of a reel (not shown) with a plate

(4) annular core support that includes an automatic position support / configuration unit, which will be described later.

In this case, the stator support (3e) formed by the insert molding method for the number of stator core assemblies is inserted between the number of stator core assemblies to integrate the number of core assemblies (3c) Stator An extension (40a) extending inwards from the core support plate (4) at the time of performing the insert molding method plays a role in fixing the housing (2) of the washing machine and simultaneously preventing the Water leaking from the washer flows into the engine.

In addition, the core support plate (4) includes a variety of automatic positioning / configuration units that will be described later. Therefore, when several sets (3c) of stator cores are mounted on the core support plate (4), a mounting position is automatically determined and simultaneously mounted in a simple way for an insert molding method, improving that way the ease of assembly work.

In Fig. 9C, the reference number (12) indicates a Hall IC assembly to generate a position signal sensing position of a rotating rotor (5) in order to control a current supply for a coil of three phase stator. Therefore, as shown in Figures 9C and 19A, an internal cylinder head (51a) in an internal cylinder head structure (8a) in the internal rotor (5a) does not extend to the lower end of the internal magnet (6a) and a part opposite to Hall IC has been removed in Hall IC set 12.

A reference number (10) indicates a cooling hole.

Since the rotor (5) of the double rotor structure is rotated by the stator (3) in the motor (1) in the same manner as in the embodiment of Figure 6, the detailed description thereof will be omitted.

That is, since the magnets (6a and 6b) of the internal rotor (5a) and the external rotor (5b) and the dividing stator core (3a) form a single complete magnetic circuit, it is possible to completely divide a stator core . Thus, a stator core can be divided into several dividing stator cores 3a, and the performance of the motor and the motor torque are increased using a double rotor.

However, when a stator core is divided into several dividing stator cores (3a), the coil winding productivity for an individual stator core (3a) is significantly higher than the case of using an integrated stator core, it is say, unique, but the productivity of the whole and the durability of it can be inferior to it.

Hereinafter, a structure will be described in detail to improve the overall productivity and durability of the assembled product of a radial core double rotor motor (1) BLDC.

Figure 10A is a perspective view of a perfect division stator core. Figure 10B is a cross-sectional view cut along the line A-A of Figure 10A. Figure 11A is an exploded perspective view showing the coupling ratio of a set of stator cores and a core support plate. Figure 11B is a partially enlarged perspective view of a core support plate. Figure 11C is an enlarged view showing a coupling state of the core support plate.

As shown in FIGS. 10A and 10B, the dividing stator core (3a) is formed substantially in the form of I. As shown, the coupling grooves (31a and 31b) whose sectional areas are semicircular shaped are vertically formed in opposite positions on both lateral surfaces. The reel (30) composed of an insulating material such as a plastic material is combined in the circumferences of the lateral surfaces. A hollow container is formed in the central part of the reel (30), and flanges (30a and 30b) extend on the inner and outer sides of the container part, respectively. A space is formed in which the coils (3b) are wound between the flanges (30a and 30b).

In addition, the reel (30) is injection molded with a general plastic material. Connecting pins (32) are inserted between the sets of individual stator cores for the mutual connection of the coils (3b) wound by phase (see Figure 11C), or through holes (33) through which they can be formed the passage of the coils on one side, both sides, or cross position of the internal flange (30a) on the reel.

In this case, it is preferable that an assembly between the I-shaped stator core (3a) and the reel (30) is molded jointly by an insert molding method using thermosetting resin.

In addition, the inner and outer flanges (30a and 30b) are formed with a relatively smaller area than the opposite outer surface of the inner and outer extensions (34a and 34b) in the I-shaped stator core (3a). In particular , the lower ends of the internal and external extensions (34a and 34b) in the stator core (3a) are separated a predetermined distance from the lower ends of the internal and external flanges (30a and 30b), respectively. The exposed parts that are not covered with the internal and external extensions (34a and 34b) of the stator core 3a in the internal and external flanges (30a and 30b) are housed and supported by internal and external guide flanges (41 and 42) in the core support plate that will be described later. In the meantime, several sets (3c) of stator cores shown in Figure 11C are mounted and an annular core support plate (4) is used as shown in Figure 11B in order to connect both ends of the two coils (3b). The core support plate (4) has a structure such that a pair of internal and external guide flanges (41 and 42) extend vertically from an annular plate 40 towards a lateral direction of the internal and external sides of the plate ( 40) annular, that is, upwards, thus housing and supporting the lower part of the core (3a) of individual stator. That is, the exposed parts that are not covered by the internal and external extensions 34a and 34b of the stator core (3a) in the flanges (30a and 30b9 internal and external of the reel (30) are housed and supported in a space (43 ) between the flanges (41 and 42) internal and external guide.

In addition, in order to automatically determine a mounting position and simultaneously maintain a support state when several sets (3c) of stator cores are mounted at the upper ends of the internal and external guide flanges (41 and 42), several first coupling projections (44a and 44b) whose cross sections are rectangular and several second coupling projections (45a and 45b) whose cross sections are semicircular extend at a predetermined interval in the internal and external guide flanges (41 and 42). In this case, the first and second projections (44a and 45a) of coupling in the internal guide flange (41) are opposed to the first and second projections (44b and 45b) of coupling in the external guide flange (42), respectively.

Therefore, as shown in Figure 11C, in each of the sets (3c) of stator cores, the second coupling projections (45a and 45b) are combined with the coupling grooves (31a and 31b) whose sections Transversals are semicircular in the stator core (3a), and the first coupling projections (44a and 44b) are combined between adjacent stator core (3c) assemblies.

As a result, in the case that several sets (3c) of stator cores are mounted using the core support plate (4), the mounting positions in the radial direction and the circumferential direction of the core sets (3c) of the stator are determined automatically by the first projections (44a and 44b) of coupling and the second projections (45a and 45b) of coupling. Therefore, a non-skilled person can mount several sets of stator cores with the core support plate (4). At the same time, since the support state for an insert molding method can be easily maintained in the following stages, the mounting productivity is truly excellent.

Furthermore, since the internal and external extensions (34a and 34b) in the stator core (3a) form the curved surface inwardly and outwardly with a predetermined curvature, respectively, in the temporarily mounted stator (3d), the Integrity of a circle combined with the internal and external circumferences of the stator core assemblies (3c) becomes high, and therefore a predetermined narrow magnetic air gap can be maintained between the internal rotor (5a) and the external rotor (5b) which are combined with the internal and external parts of the stator (3d).

The reference number (46) in Figure 11B indicates through holes for fixing the sets (3c) of stator cores to the core support plate (40), communicating the stator support body (3e) made of thermosetting resin the upper and lower parts of the core support plate (40) and forming in a solidary manner during the performance of an insert molding method as shown in Figure 9C. Reference number (47) indicates pin connection holes through which pins are combined

(32) for connection to connect the coils (3b).

Meanwhile, in the case where several sets (3c) of stator cores are mounted using the core support plate (4), several conductive lines (48) are deposited inclined on the lower surface of the plate (4) core support as shown in Figures 12A and 12B, from the pin connection holes (47a) that are arranged in the outer circumference to the pin connection holes (47b) that are arranged in the inner circumference a through the adjacent connection hole, in order to connect both ends of the coils (3b) through each phase. In this case, several conductive lines (48) of a structure contained in the recess grooves are formed, respectively (see Figure 12C). The pin connection holes (47a and 47b) are installed to penetrate the center of circular connection pads (49) that are arranged at both ends of the conductive lines (48). However, it is only possible to form a recess in the coil guide recess instead of the conductive lines.

Figures 12C to 12F are cross-sectional views showing a mutual wiring structure between the coils.

As shown in Fig. 12C, in the case of a first coil wiring method between the coils (3b), a pair of connecting pins (32) are jointly inserted into the reel (30) in the assemblies (3c) of stator cores by an insert molding method. In this case, one end and the other end of the coils (3b) are connected to the lower end of the connecting pin (32) in advance. Then, the connecting pins (32) are inserted into the sets (3c) of stator cores and mounted in the pin connection holes (47a and 47b) in the core support plate (4), and the lines (48) conductors formed on the bottom surface of the core support plate and the connecting pins (32) are fixed by welding, thus connecting the coils (3b).

As shown in Figure 12D, in the case of a second coil wiring method, one end of the coils in the stator core assemblies (3c) is passed through the through holes (33) formed in the flange (30a) in the reel and inserted into the pin connection holes (47a and 47b) in the core support plate (4). Each end of the coils and the conductive lines (48) are fixed by welding, thus connecting the coils (3b).

As shown in Fig. 12E, in the case of a third coil wiring method, a connecting pin (32) is inserted in solidarity in the spool (30) in the sets (3c) of stator cores, by an insert molding method, and one end of the coils (3b) is connected to the lower end of the pins

(32) connection in advance.

Then, the connecting pins (32) are inserted into the sets (3c) of stator cores and mounted in the pin connection holes (47a) in the core support plate (4), one end of the coils it is passed through the holes (33) through the flanges (30a) in the reel and inserted into the holes (47b and 47b) of pin connection in the core support plate (4). The coils are wound around the connecting pins (32), along the recess of the coil guide recess, and connected to each other, thus connecting the coils (3b).

As shown in Figure 12F, in the case of a fourth coil wiring method, both ends of the coils in the sets (3c) of stator cores are passed through the through holes (33) formed in the flange (30a) on the reel and inserted into the pin connection holes (47a and 47b) on the plate

(4) core support. Both ends of the coils are fixed by welding, thus connecting the coils (3b).

As described above, since coil wiring is made between the sets (3c) of stator cores by passing them through the pin connection holes (47a and 47b) in the core support plate (4) and by welding to the other end as shown in Figures 12C to 12F, a winding part and a wiring part are separated, thus improving the insulating capacity.

In addition, several conductive lines (48) formed on the lower surface of the core support plate (4) and corresponding wiring recess grooves or wiring guiding lines printed by phase are arranged along the positions of the coils to be wired. Therefore, a person welds the connecting pins (32) or coils (3b) that have crossed the pin connection holes (47a and 47b) to the end of the conductive lines (48) (see Figures 12C and 12E) . Otherwise, when the coils are wired along the guide recess grooves or printed wiring lines, any worker can easily wire the coils and the conductive lines (48).

Hereinafter, the stator assembly procedure (3) will be described.

First, each stator core 3a is inserted into a hollow reel container (30), and molded in a solidary manner by an insert molding method so that at least one connecting pin (32) is inserted into the corner part of the flanges (30a and 30b) on the reel.

Then, the coils (3b) are wound around the outer circumferences of the flanges (30a and 30b) in the reel (30) that is molded in solidarity with the stator core (3a), using a general winding machine, thus preparing several sets (3c) of stator cores.

Then, several sets (3c) of stator cores are combined at the top of the core support plate (4) that has been injection molded as shown in Figure 11A, and both ends of the coils are connected by phase on the bottom surface of the core support plate (4) according to the coil wiring method, thus obtaining the 3d stator as shown in Figure 11C.

Meanwhile, when the temporarily mounted stator (3d) of Figure 11C is used as the drive motor for a washing machine, the intensity thereof is weak to withstand a magnetic force generated during the operation of the washing machine. In addition, in order to constantly maintain an air gap between the internal and external magnets and the core, it is necessary to assume concentricity.

For this purpose, except for the opposite external surfaces of the internal and external extensions (34a and 34b) in each stator core (3a), the lower surface of the stator core (3a) is molded with thermosetting resin, for example, BMC (Bulk Molding Compound (bulk molding compound) such as polyester, so that a gap is covered between several sets (3c) of stator cores and a coil wiring part at the bottom of the plate (4) of core support, thereby obtaining a stator (3) shown in Figures 9C and 15. In this case, the extension (40a) connected to the stator support (3e) located at the bottom of the core support plate such As shown in Figure 9C, it is molded in solidarity to be used to engage with the housing (2).

In Figure 15, the reference number (12) indicates a Hall IC set.

As described above, a stator molded with an insulating material over the entire surface is used for a washing machine. Therefore, the motor adopting the stator according to the present invention can be used in a washing machine that operates in high humidity conditions during washing without requiring additional insulating material. In addition, sharp edges that can hurt operators are hidden, thus ensuring safety.

Figures 13A to 13D are views showing another embodiment, Figure 13A being an exploded perspective view showing the coupling ratio of a set of stator cores and a core support plate, Figure 13B being a view in enlarged perspective of the core support plate, FIG. 13C being an enlarged view showing a coupling state of the core support plate, and FIG. 13D being a cross-sectional view cut along the line AA of the dividing stator core of Figure 13A.

Referring to Figures 13A to 13D, a stator is shown. In this case, the cross-sectional structure of the dividing stator core (3rd) differs from that of the other embodiment. That is, the vertically formed coupling grooves are not formed on both side surfaces of the core (3a '), but several first and second projections (44' and 45 ') of coupling to automatically position and support several assemblies (3c') of stator cores in a core support plate (4 ') extend vertically directly from a plate

(40) cancel without having internal and external guide flanges.

The core support plate (4 ') includes several first coupling projections (44') whose cross section is rectangular so that it is formed at a predetermined interval concentrically inwards from the annular plate (40), and several second projections (45 ') of coupling whose cross section is in the form of a cross opposing the first several protrusions (44') of coupling formed at a predetermined interval concentrically outward from the annular plate (40).

Therefore, in this embodiment, when several sets (3c ') of stator cores are mounted on the core support plate (4'), the number of first engagement projections (44 ') is disposed between the inner faces of the number of sets (3c ') of adjacent stator cores, and the number of second projections (45') of coupling are arranged in a cross-shaped space S formed between the outer sides of the number of sets (3c ') of cores of adjacent stator. Finally, the movement of assembled sets of stator cores (3c ’) is limited. Therefore, this embodiment is simpler than the realization in view of the core support plate (4 ’), and the first also more effectively supports the number of stator core assemblies (3c’) than the last.

As described above, an insertion slit (31 ') is formed on the left and right sides between an external extension (34') of a dividing stator core (3a ') and an external flange 30b of the reel (30 ), so that a cross-shaped space S is formed between the outer sides of the sets (3c ') of adjacent stator cores.

Figure 14A is an exploded perspective view showing the coupling ratio of a set of stator cores and a core support plate according to an embodiment of the present invention. Figure 14B is an enlarged view showing a dividing stator core.

Referring to Figures 14A and 14B, in the case of a stator according to the embodiment of the present invention, a structure of several sets (3c ") of stator cores is similar to that of the second embodiment. However, the coupling projections (30c and 30d) whose cross sections are circular or rectangular extend into the internal part of the reel (30) and the internal parts of the external flanges (30c and 30b) are formed, grooves (30e- 30h) guide for wiring and guidance of coils (3b) (not shown) and coupling holes (47c and 47d) corresponding to coupling projections (30c and 30d) are drilled in the bottom of an annular plate (40) instead of several first and second projections (44 'and 45') of coupling so that several sets (3c ") of stator cores are automatically placed and supported on an annular core support plate (4").

That is, the core support plate (4 ") is formed by a press using a BMC (bulk molding compound) different from the injection molded core support plates of the first and second embodiments. In order to fix the number of sets (3c ”) of stator cores, internal and external guide flanges (41 and 42) are formed in the inner and outer circumferences of the annular plate (40), and holes are drilled simultaneously ( 47c and 47) coupling at the bottom of the annular plate. In addition, an extension (40a) in which a through hole (47e) is formed through which a stator is fixed in a housing (2) of a washing machine, is formed jointly in the internal circumference of the plate (40 ) cancel. When combined in the housing (2) of the washer, the extension (40a) plays the role of preventing water leaking from the washer and flowing down from entering the interior of the engine.

Therefore, in the stator of the embodiment of the present invention, the coils are wound around the reel (30) in which a core (3a ') is combined thus preparing sets (3c ") of stator cores, and then they insert projections (30c and 30d) of coupling and are fixed in holes (47c and 47d) formed in the core support plate (4 "). In this case, for example, a fixing structure between the coupling projections (30c and 30d) and the coupling holes (47c and 47d), prevents the front end from thermally splicing and separating after being combined by forced adjustment or a suspension structure.

Then, the coils taken from the sets (3c ") of stator cores are connected to each other by the guide grooves (30e-30h), and several sets (3c") of stator cores are subjected to an insert molding method using thermosetting resin in a manner similar to the embodiment of Figure 11A, thereby achieving durability and impermeability.

As a result, the number of sets (3c ") of stator cores can be easily mounted with the core support plate (4"). In this case, since the mounting positions in the radial and circumferential directions for the sets (3c ”) of stator cores are determined automatically, the mounting productivity is truly excellent.

Meanwhile, in the BLDC double rotor motor according to the present invention as shown in Figure 9C, the rotor (5) is supported on the cylinder head structure (8) composed of a pair of structures (8a and 8b) of internal and external cylinder head also playing the role of cylinder head internal and external rotors (5a and 5b) in which several magnets (6a and 6b) oppose each other.

As described above, the BLDC motor according to the present invention can obtain great advantages of a double rotor being able to increase the motor efficiency and the torque and eliminate disadvantages of high material cost due to a high performance magnetic material providing a motor in which the stator coils are completely divided. Furthermore, the present invention obtains great advantages of having a small amount of axial vibration of a radial core motor and eliminates the disadvantages of the high coil winding cost due to the use of the integrated stator core and a high investment cost of the installations. Due to the use of an exclusive winding machine.

The present invention can greatly improve the productivity of mounting a stator by easily and mutually connecting coils by automatically placing and fixing a plurality of stator core assemblies to a core support plate when a double rotor structure and stator core is employed. of division.

Furthermore, the present invention can improve durability and reliability by jointly molding the internal and external rotors and bearings by an insert molding method using thermosetting resin. In addition, the double rotor structure according to the present invention is suitable for a drum drive source for a washing machine that requires impermeability and durability by solidary molding a stator by an insert molding method using thermosetting resin and combining the stator together with integrated double rotors.

As described above, the present invention has been described with respect to particularly preferred embodiments. However, the present invention is not limited to the above embodiments, and for a person skilled in the art it is possible to make various modifications and variations, without departing from the appended claims.

Claims (7)

1. Brushless DC motor (BLDC) that has a radial rotor double rotor structure, comprising the BLDC motor: a rotating shaft (9) adapted to be rotatably mounted in a housing (2) of an apparatus in which the BLDC motor (1) can be mounted, a double rotor (5) that includes an internal rotor (5a) and an external rotor (5b), the central parts of the internal rotor (5a) and the external rotor (5b) being combined with the rotating shaft (9) by means of a bearing ( 7) for the rotating support, a plurality of magnets (6a, 6b) of pole N and pole S being arranged alternately in annular form in the internal and external rotor (5a, 5b), respectively, so that the annular shape of the magnets in the internal rotor is concentric to the annular shape of the magnets in the external rotor and the magnets (6a) in the internal rotor (5a) have a predetermined distance and a polarity different from that of the corresponding opposite magnets (6b) in the external rotor (5b), and an annular stator (3) adapted to be fixed to the housing (2) and installed between the internal and external rotors (5a, 5b), the stator (3) comprising several sets (3c ") of different stator cores, each comprising a stator core (3a, 3a ') and a coil (3b), a magnetic circuit that is formed by opposite magnets in the internal and external rotors (5a, 5b) having different polarities and the separate stator cores (3a; 3a ') located between the internal rotor (5a) and the rotor (5b) external, characterized because each set (3c ") of stator cores comprises an insulating reel (30) having internal and external flanges (30a, 30b) and surrounding a corresponding stator core (3a; 3a’), the coil (3b) is wound around the outer circumference of the reel (30), an annular core support plate (4 ") houses and supports the sets (3c") of stator cores on a surface thereof with a predetermined interval between them, first and second projections (30c, 30d) of coupling extend from the bottom of the inner and outer flanges (30a, 30b), respectively, of the insulation reels (30), and several first and second holes (47c, 47d) are formed in the ring core support plate (4 ") in which the first and second projections (30c, 30d) are inserted so that the assemblies ( 3c ") of stator cores are placed on the annular support plate in radial and circumferential direction, and a stator support (3e) is formed between the annular core support plate (4 ") and the various sets (3c") of stator cores by insert molding with thermosetting resin in order to integrate the assemblies (3c " ) of stator cores in the annular core support plate (4 ") in a single annular body, and an extension part (40a) extends inwardly from the core support plate (4 ") and is adapted to engage with the housing (2) of the apparatus. 2. Motor according to claim 1, characterized in that said double rotor comprises: a first cylinder head structure (8a) whose inner end is connected to the bearing (7) and having a first part curved at the other end that is perpendicularly curved to form a cup shape; a second cylinder head structure (8b) which is combined in solidarity with the first cylinder head structure (8a), and whose inner end is connected to the bearing (7), a second curved part being perpendicularly curved at the other end to maintain a equal distance with respect to the first curved part of the first cylinder head structure (8a); a plurality of first magnets (6a) of pole N and pole S alternately arranged annularly on the outer circumferential surface of the first curved part; Y a plurality of second magnets (6b) of pole N and pole S alternately arranged annularly on the inner circumferential surface of the second curved part so that the magnets (6a, 6b) in the first and second curved portions that are arranged opposite each other have different polarities. 3. Motor according to claim 1, characterized in that said double rotor (50) comprises: an internal rotor (50a) having a cylindrical internal cylinder head (51a) and a plurality of first magnets (6a) of pole N and pole S which are alternately arranged annularly on the outer circumferential surface of the cylinder head (51a) internal; an external rotor (50b) having an external cylinder head (51b) having a diameter greater than that of the internal cylinder head (51a) to maintain an equal distance from the internal cylinder head (51a), and a plurality of second magnets (6b) of pole N and pole S alternately arranged annularly on the inner circumferential surface of the outer cylinder head (51b) so that the magnets (6a, 6b) on the inner and outer cylinder heads (51a, 51b) which are arranged opposite they have different polarities with each other; Y an annular rotor support (53) formed in a integral manner that forms a space in which the stator (3) is inserted between the internal and external rotors (50a, 50b), and which is molded with thermosetting resin so that the end Its internal is connected to the outer circumferential surface of the bearing (7a).

Four.

Motor according to claim 1, characterized in that the apparatus for which the rotating shaft (9) is adapted is a washing drum of a washing machine.

5.

Motor according to claim 3, characterized in that several cooling holes (10) are formed to cool the stator coils (3b) in the rotor support (53) between the internal and external rotors (50a and 50b).

6.

Motor according to claim 1, characterized in that several cooling fan blades (54) are formed integrally in the lower surface of the external rotor (50b), so that air cooling for the stator (3) is carried out during the rotation of the rotors (5).

7.

Motor according to claim 1, characterized in that one end of the rotating shaft (9) is connected to the double rotor (5) by means of a bearing (7), and the other end of the rotating shaft (9) is rotatably supported by a support ( 11) adapted to be installed in the housing (2) of a washing machine.