KR100213571B1 - Double rotor/single stator and coreless-type bldc motor using one-body type stator - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coreless brushless DC motor (hereinafter referred to as a coreless type BLDC) motor, and more particularly to an integral type stator using a rectangular bobbin coil or a bobbin non- And a double-rotor / single-stator type coreless BLDC motor using the same.

The coreless type BLDC motor of the present invention comprises first and second rotors arranged in a disk shape in which a plurality of sets of N-pole and S-pole magnets are alternately arranged at a predetermined interval, An upper and a lower case rotatably supporting the rotary shaft, and an electromagnetic force in a direction opposite to the first and the second rotor is applied to the first and second rotors, respectively, with a predetermined gap between the first and second rotors, A plurality of stator coils wound around a plurality of rectangular bobbins are supported by a molding filler to form an annular disc-shaped stator.

Therefore, the motor of the present invention is a structure in which the axial direction is small in vibration, high in torque, excellent in durability, and low in manufacturing cost.

Description

Double-rotor / single-stator coreless bi-DC motor with integrated stator

FIG. 1 is an axial sectional view showing a conventional coreless BLDC motor structure; FIG.

FIG. 2 is an axial cross-sectional view showing a double-rotor / stator type coreless type BLDC motor structure having the same driving principle as the present invention.

3 is a plan view showing the rotor structure shown in FIG. 2; FIG.

Figures 4a and 4b are a top view and side view, respectively, showing another structure of the rotor shown in Figure 2;

5a and 5b are a top view and a cross-sectional view taken along line A-A of the stator assembly according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view of a partially-bladed single-stator coreless BLDC motor using a stator assembly according to a first embodiment of the present invention.

7 is an explanatory view showing the arrangement relationship between the stator coil and the rotor magnet in Fig. 6; Fig.

FIG. 8 is a partial cross-sectional view showing a coreless BLDC motor structure of a two-stage further rotor / stator type according to a first embodiment of the present invention; FIG.

9a and 9b are a top view, a partially cut front view, and a rear view, respectively, of a stator assembly according to a second embodiment of the present invention.

10 is a partial cut-away axial cross-sectional view of a single-stage double-row / single-stator type coreless BLDC motor using the stator assembly of the second embodiment according to the present invention.

FIG. 11 is a partial cross-sectional view of a coreless BLDC motor of a two-stage double rotor / single stator type according to a second embodiment of the present invention; FIG.

FIG. 12 is a partially cutaway sectional view showing a modification to the motor case. FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

1: annular magnet 3: yoke

5: Rotor 5A, 5B: Magnet

7: rotating shaft 9: PCB

11: stator coil 13:

15: Bearing 17: Buffer spring

20A, 20B: Left / right case 21: PCB

23: bushing 25, 26: bobbinless stator coil

27, 29: first and second stator 31:

33, 35: first and second rotors 37: yoke

39, 41: bearings 43A, 43B: E-ring

44: Connector 45A to 45H: Magnet

51: stator assembly 53: square bobbin

55: coil 57: auxiliary PCB

59: stator body 61: through hole

63A, 63B: upper / lower terminal 65: through hole

67: outer peripheral portion 71A, 71B: upper / lower case

73A, 73B: upper / lower rotors 75A, 75B: bushing

77: rotating shaft 79: supporting body

81A and 81B: Magnets 83A and 83B: Magnet yoke

85: auxiliary magnet 87: control PCB

89: Hall element 91: female connector

93A, 93B: Bearing 95: Spacing bushing

97: Fixing screw 99: Power IC

101: Through hole 103: Aℓ disk

251: stator assembly 255: bobbinless coil

253A: keyway 253B: projecting key

257A: short ring 257B: auxiliary PCB

259A: stator holder 259B: stator body

263A: upper terminal 263B: lower terminal

297A: Through hole F1: Repulsive force

F2: Suction power

The present invention relates to a coreless brushless DC motor (hereinafter referred to as a coreless type BLDC) motor, and more particularly to a coreless brushless DC motor which is inexpensive to manufacture by using a rectangular bobbin coil manufactured by a general- Rotor type single-stator type coreless type BLDC motor having a connection structure in which mutual connection between adjacent stages can be easily performed.

BLDC motors are divided into a core type (or radial type) and a coreless type (or an axial type) having a cup (cylindrical) structure according to whether they have a stator core or not.

The BLDC motor of the core structure has an inner magnet type comprising a cylindrical stator in which a coil is wound to have an electromagnet structure on a plurality of projections formed on an inner peripheral portion and a rotor made of a cylindrical permanent magnet, A coil is wound in an up / down direction, and a cylindrical permanent magnet, which is multipolar-magnetized outside thereof, is classified into an external magnet type in which the rotor is constituted.

Since the core type BLDC motor has a structure in which the magnetic circuit is symmetrical in the radial direction about the axis, it has advantages of low vibration noise, good in low speed rotation and good in torque, And the cost of equipment investment is high at the time of mass production. Further, the structure of the stator and the rotor is complicated, the thinning is disadvantageous, the high efficiency is difficult to achieve, and cogging torque is generated.

The conventional coreless BLDC motor proposed to improve the disadvantages of the core-type BLDC motor described above has a structure in which a rotor 5 composed of an annular magnet 1 and a yoke 3 as shown in FIG. And has a structure in which the rotating shaft 7 is coupled through a bearing 15 to a stator 13 fixedly coupled to the stator 7 and having a plurality of stator coils 11 wound on a printed circuit board have.

As shown in FIG. 3, the coreless BLDC motor includes a rotor 5 having a plurality of magnets integrally formed thereon, and a stator 13 having a stator coil for generating a large number of sets of electromagnetic force Even if the buffer spring 17 is inserted between the bearings 15 due to the suction or repulsive force of the stator and the uneven magnetism of the stator, The vibration occurs in a large structural manner.

In addition, the vibration in the axial direction causes the resonance of the whole system at the time of rotating the motor, thereby increasing the rotational noise. Therefore, the overall efficiency of the motor during high-speed rotation is good because there is no loss, while vibrational noise is synthesized in the rotating noise, which may cause abnormal noise.

As a result, it is possible to minimize the material loss compared to the core-type BLDC motor, and to achieve mass production, thickness reduction, and downsizing, thereby achieving low cost and high efficiency. However, it has a fatal flaw .

This application claims priority from Japanese Patent Application Nos. 96-976 and 977, filed on Jan. 18, 1996, which disclose a double rotor / stator type rotor which can offset the axial vibrations generated during rotor rotation and increase the torque more than twice A coreless BLDC motor has been proposed.

For example, as shown in FIGS. 2 to 4, the coreless BLDC motor proposed in the above-mentioned Japanese Patent Application No. 96-977 includes a plurality of sets of N-pole and S-pole magnets 5A, 5B: 45A Like first and second rotors 33 and 35 disposed alternately with each other, a rotary shaft 31 coupled to the center of the rotor through a bushing 23, The left and right cases 20A and 20B are respectively provided with a predetermined gap between the first and second rotors and are provided with a plurality of bobbinless stators 20A and 20B for applying electromagnetic force in opposite directions to the first and second rotors, And first and second stator (27, 29) having coils (25, 26).

In FIG. 2, reference numeral 37 denotes a yoke, reference numerals 39 and 41 denote bearings, reference numerals 43A and 43B denote E-rings for fixing a bushing, and reference numeral 44 denotes a drive current supply connector.

In the above-mentioned prior art, a plurality of coiled stator coils 25 and 26 are disposed in the middle of the first and second blotters 33 and 35, respectively, and have a double stator structure in which the stator coils 25 and 26 are mounted on the left and right sides of the PCB 21, 29, and the rotor rotating shaft 31 are formed.

In this case, the corresponding stator coils 25 and 26 of the first and second stator wind the corresponding magnets 45A to 45H of the first and second rotating rotors so as to attract each other or to repel each other, Flow direction is set. The first and second rotors 33 and 35 are subjected to the attractive force F2 or the repulsive force F1 of the same magnitude opposite to each other by the first and second stators 27 and 29, 29 are offset from each other by the attractive force F2 or the striking force F1 acting on the first and second rotors 33, 35, so that the axial vibration of the rotor is minimized.

The double stator assembly of the coreless type BLDC motor of the double rotor / stator type has a bobbin-less angle coil wound up and down using a bonding wire on both sides of the PCB 21, Solder the terminals and connect them.

However, the bonding wires of these bobbinless coils are 1.5 ~ 2 times more expensive than general copper wires and 12 (in case of 60 ° conduction angle) should be arranged concentrically in the double rotor / stator structure. Furthermore, The winding machine is a dedicated winding machine of a hot-air fusing type and has a disadvantage in that it is more expensive to manufacture than a general winding machine and is difficult to be generalized.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a bobbin coil with a universal winding machine, which has reliable insulation between windings, excellent moisture absorption, vibration absorbing and corrosion resistance, Shaped stator assembly capable of manufacturing a stator at a low cost when winding the stator.

It is a second object of the present invention to provide a double rotor / rotor assembly which can be easily interconnected with adjacent stages in a multi-layered structure using a molding stator assembly, A single stator type coreless type BLDC motor.

It is a third object of the present invention to provide a double-rotor / multi-stator coaxial connector in which a control PCB for supplying a driving current to a stator coil is built in an upper / lower case and an electrical / mechanical connection to the stator assembly is automatically performed, A single stator type coreless type BLDC motor.

In order to achieve the above object, according to the present invention, a plurality of sets of N-pole and S-pole magnets are alternately arranged at a predetermined interval from one another, An upper / lower case rotatably supporting the rotary shaft; and a second rotor which is coupled to the rotor via a bushing at a center of the rotor, A control printed circuit board installed in one of the upper and lower cases to apply a driving current to the stator, and a control printed circuit board disposed between the stator and the control printed circuit board, And a connecting means for electrically connecting the substrate to the substrate and automatically connecting the substrates to the opposed positions set mechanically, The electromagnetic driving / axial direction vibration preventing means includes a plurality of stator coils for applying an electromagnetic force to the first and second rotors, and the outer periphery thereof is positioned as a self-aligning structure between the upper and lower cases And a coreless stator which is coupled to the first rotor and the second rotor and has a predetermined gap between the first rotor and the second rotor and is formed in the shape of an annular disk by a molding filler, And a current flows to generate a magnetic flux having the same axial direction of polarity when the corresponding magnet has an opposite polarity and generate an electromagnetic force applied in an opposite direction to the first and second rotors. Type core-less BI DC motor.

According to another aspect of the present invention, there is provided a method of manufacturing a stator for a coreless BLDC motor, comprising: a first step of disposing a plurality of winding coils on an annular printed circuit board at equal intervals to connect and fix terminals of each coil; There is provided a method for manufacturing a stator of a coreless type BLDC motor, characterized in that the outer peripheral surface of the wound coil assembled in Step 1 is molded by a molding method in the form of a disk having a through hole at the center by using a molding filling material .

As described above, in the present invention, the rectangular coil is formed as a bobbin coil using a general-purpose winding machine, and a plurality of bobbin coils thus prepared are assembled together with an auxiliary PCB by an insert molding method.

Therefore, it is possible to manufacture square-shaped coils by using general insulated copper wire without using bonding wires, and by using multi-axis or single-axis general-purpose coils, at low manufacturing cost.

In addition, compared with insert molding, the outside of the coil is sealed as an insulator such as resin, so that insulation performance against each coil, case, and dea metal is excellent, and moisture resistance, corrosion resistance and mechanical strength are also guaranteed.

Further, in the present invention, the stator assembly is manufactured by the insert molding method using a bobbin type coil instead of the bobbin type coil, so that the durability can be improved while increasing the output and efficiency of the motor.

[Example]

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

5A and 5B are a plan view and a cross-sectional view taken along line AA of the stator assembly according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view of the BLDC motor of the single- FIG. 7 is an explanatory view showing the arrangement relationship between the stator coil and the rotor magnet in FIG. 7; FIG. 8 is a partial cross-sectional view of the BLDC motor in the two-stage structure according to the present invention;

5A and 5B, the stator assembly 51 is rectangularly wound on a plastic rectangular bobbin 53 by a coil 55. Six such rectangular bobbin coils 55 are inserted into a molding die, (PCB) 57 which allows interconnections to be made with respect to the coils.

A through hole 61 is formed at the center of the auxiliary PCB 57 and the stator body 59. A through hole 61 is formed at one side of the stator body 59 for electrical connection with the control PCB 87 shown in FIG. When the upper terminal 63A and the multi-layered laminate structure are employed, the lower terminal 63B for electrical connection with the stator assembly at the other end is buried.

In the three-phase drive system, the stator cores 55 of the stator assemblies are divided into six groups of six coils and wound around a rectangular bobbin 53 having a sector-shaped through hole 65 at the center thereof, Y system, and in the two-phase-wave magnetic-wave driving system, two stator coils are wound in eight and connected in series.

The bobbin coil 55 can be wound in a general single-shaft and multi-spindle winding machine that is easy to automate using a plastic square bobbin 53 without using a separate dedicated winding machine. Therefore, facility investment can be minimized during mass production.

In this case, the coil used for winding the bobbin coil 55 is not a conventional bonding wire but a general insulated copper wire whose price is 25% to 50% lower than the conventional one can be used, so that the coil cost can be reduced by at least 50% have.

Furthermore, since the bobbin coil 55 forms the stator assembly 51 with the exposed portion of the coil sealed with the resin insulating material, the bobbin coil 55 is reliably insulated between the square-shaped coils 55 wound around the rectangular bobbin 53, It is also excellent in dampproof, vibration absorbing and corrosion resistance.

In addition, since the rectangular coil 55 is wound around the bobbin 53 and molded into a disk shape, the mechanical support strength can be greatly improved as compared with the conventional structure in which the rectangular coil is attached to both surfaces of the PCB with an adhesive .

Meanwhile, in the structure of the present invention, the control PCB 87, which supplies the driving current to the stator 55 through the upper / lower terminals 63A and 63B, can be easily electrically connected to the adjacent stator assembly in the laminated structure, The motor design of the large capacity output for the axial laminated structure is easy and the structure for assembly productivity is high.

A double rotor / single stator type coreless BLDC motor constructed using the above-described stator assembly 51 will be described with reference to FIG.

6, the BLDC motor is formed so that the outer peripheral portion 67 of the stator assembly 51 extends upward / downward in the middle of the upper / lower cases 71A and 71B, and is coupled between them to form a cylindrical case.

An upper rotor 73A and a lower rotor 73B having a predetermined air gap and having a magnet divided multi-pole arrangement structure are mounted on upper and lower portions of the stator assembly 51 via rotary shafts 77 As shown in Fig.

Each of the rotors 73A and 73B includes eight magnets 81A and 81B, that is, four disk type N-pole magnets and four disk type S-pole magnets alternately made of a non-magnetic material such as PET, nylon 66 or PBT 83A and 83B are integrally attached to the back surface of the supporting body 79 integrally formed with the bushings 75A and 75B to form a magnetic circuit for the eight magnets 81 Structure.

The mutual positional relationship between the eight magnets 81A and 81B and the rectangular coil 55 of the stator assembly 51 is such that the disc shaped magnets 81A and 81B with a hatched pattern are arranged in a square shape as shown in FIG. Hole 65 of the bobbin 53, that is, the through-hole 65 of the rectangular coil 55. As shown in Fig.

On the other hand, an auxiliary magnet 85 for detecting the Hall element position is attached to the upper side of the magnet yoke 83A of the upper rotor 73A. The auxiliary magnet 85 is mounted on a control PCB Is disposed opposite to the Hall element (89) of the Hall element (87). Also, at one side of the control PCB 87, a female connector 91 for press-fitting the upper terminal 63A of the stator assembly 51 is provided.

Upper and lower bearings 93A and 93B are fixed to the central portions of the upper case 71A and the lower case 71B and the rotary shaft 77 of the rotors 73A and 73B is connected to the bearings 93A and 93B. Is rotatably supported.

In FIG. 6, reference numeral 95 denotes a gap maintaining sleeve and reference numeral 97 denotes a fixing screw (bolt) for fixing the upper and lower cases 71A and 71B.

When the driving current is applied to the stator coil 55 in the same manner as the BLDC motor of the preliminary discharge shown in FIG. 2, the magnetic field is formed in a predetermined setting direction.

The magnets 81A and 81B of the upper and lower rotors 73A and 73B and the magnets 81A and 81B of the upper and lower rotors 73A and 73B, The same repulsive force F1 or attraction force F2 acts between the coils 55 of the coil spring 55. [

Therefore, the repulsive force F1 or the attractive force F2 acts in opposite directions to cancel each other, so that the rotations of the rotors 73A and 73B are performed while the axial vibration is kept at a minimum.

The above-described structure provides a motor with a drive torque twice that of a single stator / single rotor structure on the same principle as the present invention.

In addition, at the same time, the stator can be formed as a single body and the coil can be wound / assembled by using the bobbin, so that high productivity and low manufacturing cost can be realized and the durability of the whole motor can be increased.

FIG. 8 shows a BLDC motor of a two-stage adaptive structure according to the present invention, wherein like reference numerals in FIG. 6 denote like elements.

That is, the BLDC motor of the two-stage structure has a structure in which the two stator assemblies 51A and 51B are surrounded by the upper and lower rotors 73A and 73B and 73C and 73D, respectively.

The motor of the two-stage laminated structure is rotated by the same operation as the motor of the above-described one-stage structure and the rotary shaft 77 is rotated, so that the description thereof is omitted.

As described above, in the structure of the present invention, when the output of the motor is doubled by the laminated structure, the interconnection between the ends is connected to the bushings 75A to 75D through the upper / lower terminals 63A and 63B So that the assembling productivity is high while the overall structure is compact, and the weight can be largely reduced as compared with other motors of the same capacity.

9a and 9b are plan views of a stator assembly according to a second embodiment of the present invention. Figure 9a is a partial cutaway front view and a rear view.

The second embodiment differs from the first embodiment in that in the case of the second embodiment, the stator assembly 251 is integrally formed by the insert molding method using the bobbin response coil 255 instead of the bobbin coil.

In manufacturing the stator assembly 251 of the second embodiment, first, the six bobbin non-return coils 255 are connected by an annular short ring (not shown) made of a conductor for interconnecting the neutral points of six bobbin non- 257A and an annular auxiliary PCB 257B having a larger diameter than the short ring 257A using a coil assembly jig.

Thereafter, the coil assembly is molded with a resin material into a stator body 259B by an insert molding method together with an annular stator holder 259A in which a resin material is molded in advance, thereby manufacturing a stator assembly 251. [

In this case, for example, three upper terminals 263A and a lower terminal 263B connected thereto are embedded in the stator holder 259A so as to protrude to the opposite sides. When fixed to the motor case, bolt fastening through holes 297A Are formed, for example, three.

A key groove 253A and a protruding key 253B for automatically aligning the engaging position at the time of assembling with the motor case or another single stator holder to be described later are formed on the upper and lower outer peripheries of the stator holder 259A .

When the stator assembly is assembled using the bobbinless coil as described above, the coil width of the coil is reduced by the bobbin thickness as compared with the stator assembly of the first embodiment, so that the density of the flux linkage in the air gap is increased. That is, the magnetic flux density increases.

For example, when the bobbin thickness is reduced by 0.5 mm × 2, a reduction of 1 mm is obtained. As a result, the output and efficiency increase of about 4% can be expected if only the air gap is used as the variable in the same specification.

On the other hand, a single-stage double rotor / single stator type coreless type BLDC motor constructed using the stator assembly of the second embodiment is shown in FIG. 10, and a two-stage BLDC motor is shown in FIG. .

In the motor using the second embodiment shown in Figs. 10 and 11, the same parts as those in the first embodiment are given the same reference numerals.

The operation of the second embodiment is performed in the same manner as that of the first embodiment, and a description thereof will be omitted.

The motor structure shown in FIG. 12 shows an example in which case material is made lighter by using synthetic resin or the like.

In this case, the upper case 71A may be made of a resin material such as a stator holder.

In this example, a through hole 101 for radiating power IC or TR module 99 mounted on the upper surface of the control PCB 87 is formed on one side of the upper case 71A, The lower surface of the power IC 99 is brought into contact with the power IC 99 to be fixed by the fixing bolt 97 with the Aℓ plate 103 serving as a heat sink.

When the motor of the present invention having the above-described configuration has the same output as that of the conventional core-type BLDC motor, the size of the motor can be about 1/2 and the weight can be about 1/3 as shown in Table 1 below. Weight reduction can be achieved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limited to the embodiments set forth herein. Various changes and modifications may be made by those skilled in the art.

For example, the rotor can adopt the integrated multipolar magnetization structure shown in FIG. 3, and the number of bobbinless stator coils mounted on the stator PCB according to the motor drive method can be varied. In addition, the motor output can be easily increased by increasing the motor stacking number in this manner.

Also, the keyway and the protruding key described above can be applied to the first embodiment, and the assembling method of the second embodiment can be applied in the same manner when assembling the first embodiment.

Claims (9)

A first rotor and a second rotor each having a plurality of sets of N-poles and S-poles arranged alternately in a disk shape, the first and second rotors having opposed polarities opposite to each other, An upper / lower case rotatably supporting the rotary shaft, and an electromagnetic driving / shaft for generating a rotary driving force for the rotor and preventing axial vibration in association with the generation of the rotary driving force, A control printed circuit board installed in one of the upper and lower cases for applying a driving current to the stator and a control printed circuit board for electrically connecting the stator and the control printed circuit board, Wherein the electromagnetic driving / axial direction vibration preventing means comprises a connecting means for automatically connecting the electromagnetic driving / And a plurality of stator coils for applying an electromagnetic force to the first rotor and the second rotor, the outer periphery being positioned and coupled as a self-aligning structure between the upper and lower cases, Wherein the coils of the stator have the same polarity as the corresponding magnets of the first and second rotors, respectively, and the coils of the stator have the same polarity as the corresponding magnets of the first and second rotors, And a current flows to generate a magnetic flux having a direction polarity direction and generate an electromagnetic force applied to the first and second rotors in a direction opposite to the first and second rotors. The magnet assembly according to claim 1, wherein each of the rotors comprises: a support made of a disk-shaped non-magnetic material; a plurality of sets of N pole magnet and S pole magnet inserted alternately at equal intervals in the support; And a yoke. The double rotor / single stator coreless bi-DC motor. The stator of claim 1, wherein the stator comprises: a plurality of winding coils; a stator body that supports the square-shaped coils in an annular disc shape as a whole while sealing exposed portions of the winding coils; And an auxiliary printed circuit board for connecting the printed circuit board to the printed circuit board. 4. The double rotor / single stator type coreless type BD motor according to claim 3, wherein the plurality of coils are wound on a bobbin. The double-rotor / single-stator type coreless type Billundishie motor according to any one of claims 1, 3, and 4, further comprising a short ring for interconnecting the neutral points of the plurality of coils. The stator of claim 1 or 3, wherein the stator has a key groove and a protruding key formed on the upper and lower portions of the outer circumferential portion so as to be automatically aligned when assembled with the upper and lower cases. Les Type Bielsis Motor. The printed circuit board according to claim 1, wherein the connecting means comprises: a plurality of first male terminals extending in parallel to the axial direction of the stator; and a plurality of second male terminals formed on the control printed circuit board, And a plurality of second female terminals electrically / mechanically connected to each other. The double rotor / single stator type motor according to claim 1, further comprising a single-stage motor of at least one double rotor / single stator structure stacked in a single-stage motor of a double rotor / Coreless type BIST engine. The double-rotor / single-stator type coreless type BLDC motor according to claim 4, wherein the winding coil is obtained by winding an insulating coil on a rectangular bobbin using a normal winding machine.