SINGLE PHASE BRUSHLESS AND SENSORLESS DIRECT CURRENT DYNAMO- TYPE MOTOR ASSEMBLY AND METHOD OF DRIVING USING THEREOF

Technical Field The present invention relates to a single phase brushless and sensorless direct- current dynamo-type motor assembly and a method of dπving using thereof, more particularly, to a so-called single phase brushless and sensorless direct-current (BLSLDC) dynamo-type motor assembly and a method of dπving using thereof which doesn't require a mechanical contact point such as a brush for electrically connecting to a coil and an additional sensor for dπving a rotor

Background Art

A conventional BLDC motor assembly mainly refers to a motor and a related system converting electπcal energy into mechanical energy. As shown in Fig. 1, the conventional BLDC motor assembly compπses a rotor 3 which is an rotating assembled permanent magnet, a stator 2 which is an assembly of multiple coils with multiple phases for generating an impetus corresponding to electπc force, a sensor for detecting a position of the rotor, and a dπve/control circuit thereof.

That is, it is the essential point of the technology shown in Fig. 1 that it employs the rotor being an assembled permanent magnet to remove a brush which is an electromechanical contacting part. As the brush is removed, it provides advantages such as reduced contact noise, extended life cycle, high-speed dπve, and rotating force with high RPM.

Such a conventional BLDC motor may be distinguished as an exteπor-wheel-dπve type having a central shaft being fixed and an exteπor wheel being rotating, and an inteπor-wheel-dπve type having a central shaft being rotating and an exteπor wheel being fixed, based on the arrangement of the rotator consisting the magnetic field of the permanent magnet.

As an additional descπption on the structural characteπstics of the conventional BLDC motor, a gap where magnetic field of the permanent magnet and magnetic field of a coil react each other is formed along an inner peπpheral of the rotator in a direction perpendicular to the central shaft in the exteπor-wheel-dπve type, while the gap is formed along the outer peπpheral of the rotator in a direction parallel with the central shaft in the inteπor-wheel-dπve type Such a conventional exteπor-wheel-dπve type motor is advantageous for constant speed due to a high moment of inertia of the rotator, as well as for high efficiency/high- torque due to magnified volume or size of the permanent magnet. The inteπor-wheel-dπve

type motor is advantageous for high speed.

A linear motor, which is named after its shape, is driven by electromagnetic force applied to the gap between a mover and a stator according to a mutual electromagnetic reaction between magnetic field generated by the permanent magnet and electromotive force generated on the coil by current supplied from a control system. Herein, its performance is determined by fundamental structure and arrangement such as material of the permanent magnet and the number of turns.

Based on the type of model, the linear motor is distinguished as a synchronous type in which one sides of a mover and a stator are formed with a magnetic pole and the other sides thereof are formed with a coil so that the coil is supplied with the power to generate electromagnetic force, and an asynchronous type in which one sides of a mover and a stator are formed with conductive plates and the other sides thereof are formed with flat coil having a groove being inserted with a three-phase winding in order to generate the electromagnetic force according to three-phase indirect current method. Also, based on the structure of the mover or the stator, there exist methods of using the coil as the mover and the permanent magnet as the stator, and vice versa.

Disclosure of Invention

Technical Problem However, in case of conventional technology, the permanent magnets consisting the magnetic circuit of the rotator are basically arranged in opposing polarities regardless of types such as interior-wheel-type, exterior-wheel-type, and linear type. Because of such reason, the coil has a plurality of arrangement having positions synchronized with the magnetic poles of the permanent magnets, which is driven by a power source with multiple phases.

Accordingly, not only manufacturing cost rises due to the complexity of the manufacturing process of the motor and its drive system, but also it has critical weakness that, for most of cases, there exists undrivable areas inevitably due to use of the multi- polarized permanent magnet. Since 1990, studies have been done for minimizing the undrivable area

(theoretically, possible up to zero point), reducing cogging phenomenon, reducing torque ripple, and reducing the manufacturing process. However, all those effort didn't result in economic benefit such as alternative manufacturing process with reduced cost, as the studies are mostly focused on a system perspective such as reliability, sensing of a sensor, solution by a drive method.

Characteristic of the conventional BLDC motor has been described above. For most of the conventional BLDC motors manufactured since 1985, it has been already disclosed

about a plurality of pπor technologies related to the conventional BLDC based on the basic structure descπbed above as well as its analysis and implementation. Accordingly, detail descπptions on technology oπginated separately from such a conventional technology will be omitted. As exemplary pπor arts of conventional BLSLDC motor technology, Korean utility model patent publication Nos. 20-0206537 and 20-0193120 disclose "a direct current generator without a commutator and a brush", which is descπbed schematically in Fig. 2.

As shown in Fig. 2, in case of the direct current generator without a commutator and a brush according to Korean utility model patent publication No. 20-0193120, it is discloses that an armature is wound against a cylindπcal armature core with an armature coil 4 along an axis direction and fixed on a generator main body, magnetic poles are made as dual cylindrical poles which are arranged as a seπes of one particular pole 5 of N pole or S pole in a sequence such as N-N-N poles or S-S-S poles, so that poles are rotated to generate a direct current as the dual cylindπcal poles are inserted into the cylindncal armature core.

However, arranging poles only with one particular pole (with only Ns or Ss) denies the basic law of nature regarding electromagnetics, therefore, it is not feasible. Also, in case of a brushless direct current generator with a commutator having an armature and poles in shape of doughnut according to Korean utility model patent publication No. 20- 0206537, it is disclosed that a pole facing an armature having N polaπty should have N polanty and a pole facing an armature having S polaπty should have S polaπty. However, just like the case mentioned above, a specific implementation method for making poles and armatures of same polaπty facing each other is not disclosed. Besides, it is impossible to realize such an arrangement, which constitutes incomplete invention. Also, a method of winding of armature for an axial flux permanent magnet coreless machines according to Korean patent application no. 10-2004-0002941 may have a disadvantage that there may exit an undπvable area due to the fact that permanent magnets on upper and lower sides opposed to each other have a plurality of magnetic poles on each side. This invention may be advantageous in that coil windings can be disposed evenly. Yet, it still contains another disadvantage that its magnetic flux density deteπorates as it has the intnnsic disadvantage of mechanical durability defect which is caused by magnetic fields not being aligned in the coreless motor.

Fig. 3 is a perspective view on a schematic structure of a typical linear motor according to conventional technology. As shown in Fig. 3, the linear motor that has a permanent magnet as a stator 8 and a coil as a mover 7 has an advantage that the mover 7 is light and structure of the stator 8 is simple. Meanwhile, it has a disadvantage that the accurate control of stator 8 is hard due

to interruption on a cable occurring as turning on the power.

Contrary, when the permanent magnet is used as the mover and the coil is used as the stator, the interruption on the mover can be minimized, mobility may be enhanced, and control of the mover becomes easy. However, it still has a problem that it is hard to supply the power to the coil.

To solve all those problems mentioned above, Korean patent no. 10-0399423(refer to Fig. 2) discloses a patent characteπzed in that conducting part of the coil is bent perpendicularly to form "U" shape so that 3 coils can be dπven by three-phase power and that the mover is formed as a mover base having shape of "M" by combining members with a predetermined length. A motor according to this invention has an advantage that it has a high thrust compared to volume and it minimizes interruption caused by a cable.

Although the invention mentioned above allegedly minimizes the interruption caused by the cable, it still has a disadvantage that the power supply to the core is difficult with the three-phase power. Besides, it has a disadvantage that the structure of a coil 9 consisting the permanent magnet is complicate, as shown in Fig. 2, production cost πses as it takes a method of utilizing a sensor to remove undπvable area, and it is difficult to commercialize due to difficulty of installation.

Technical Solution The present invention is devised to solve problems mentioned above. An objective of the present invention is achieved by providing a motor provided with brushless single- phase inteπor and exteπor wheel driving rotor, which has direction of permanent magnets within gaps vertically aligned, and by realizing a dynamotor minimizing torque πpple and cogging and a driving/generating method thereof. An another objective of the present invention is achieved by providing a motor which has a simple structure and requires relatively cheap manufactuπng cost by removing an undπvable area without sensor for detecting a position of a rotor for dπving.

An another objective of the present invention is achieved by providing a high efficient BLDC single phase dynamotor of size ranging from micromini-size to extra large size and driving/generating method thereof which is capable of dπving at high torque/high speed and generating direct current of high voltage/high current.

An another objective of the present invention is achieved by providing a linear motor which has direction of magnetic field of permanent magnets aligned vertically within the gap, has less magnetic field loss, and facilitates supplying power.

Advantageous Effects As descπbed above, the single phase brushless and sensorless direct-current

dynamo-type motor assembly according to the present invention has a direction of the magnetic field within the applying gap aligned linearly, so that magnetic loss can be minimized. Also, it has an advantage of minimizing torqueless πpple and cogging.

Additionally, by providing a single phase method, undπvable area which is a problem the lies within multiple poles method can be removed. In this way, as a sensor for detecting a position of the rotor for dπving is unnecessary, a manufacturing process can be reduced and the manufacturing cost can be minimized relatively.

Also, as dπving at high torque/high speed and generating direct current of high voltage/high current can be possible at size ranging from micromini-size to extra large size, additional effects are expected such as energy conversion of a high efficiency, competitiveness in the market in accordance with the minimized manufactuπng cost, activation of the related industπes requiπng the high efficient electπc power, activation of the related industries requinng clean recycling energy and realization of low cost local generation, competitiveness in the field of components related to motor and generator, procuring additional growth momentum for next generation of the nation

Additionally, with an assumption of an infinitely extended rail made of permanent magnet in the linear motor and a smooth power supply, the present invention can be applied to the express train. Besides, if the rail can be build by a plurality of separate coils, it can be applied to a complete automatic train system.

Description of Drawings

These and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following descπption of the aspects, taken in conjunction with the accompany drawings of which: FIG. l is a plane view of a brushless motor according to conventional technology.

Fig 2 is a schematics of a brushless direct current generator according to conventional technology.

Fig. 3 is a perspective view of a representative structure of a linear motor according to conventional technology. Fig. 4 is a plane view of a coil being a permanent magnet used in a linear motor according to conventional technology.

Fig. 5 is a cross sectional view of a motor assembly provided with an inteπor wheel dπving rotor according to a first embodiment of the present invention.

Fig 6 is an exploded cross sectional view of a motor assembly provided with an inteπor wheel dπving rotor according to a first embodiment of the present invention

Fig. 7a is a cross sectional view of an assembled state of rotor yoke and shaft assembly of a motor assembly provided with an inteπor wheel dπving rotor according to

a first embodiment of the present invention

Fig. 7b is a cross sectional view of stator yoke of a motor assembly provided with an interior wheel dπving rotor according to a first embodiment of the present invention

Fig. 7c is a plane view and cross sectional view of a motor assembly provided with an inteπor wheel and exteπor wheel dπving rotor according to first and second embodiments of the present invention.

Figs. 8a, 8b, and 8c illustrates an operation principle of a motor assembly provided with an interior wheel dπving rotor according to a first embodiment of the present invention. Fig. 9a illustrates an embodiment of a permanent magnet of a motor assembly provided with an inteπor wheel dπving rotor according to a first embodiment of the present invention.

Fig. 9b illustrates an another embodiment of a permanent magnet of a motor assembly provided with an inteπor wheel dπving rotor according to a first embodiment of the present invention.

Fig. 10a illustrates an arrangement of split windings of fixed coil of a motor assembly provided with an inteπor wheel and exteπor wheel dπving rotor according to first and second embodiments of the present invention.

Fig. 10b illustrates a plane view and a partially zoomed cross sectional view of a core yoke and a coil of a motor assembly provided with an inteπor wheel and exteπor wheel dπving rotor according to first and second embodiments of the present invention.'

Fig. 11 is a cross sectional view of a structure of a motor assembly provided with an exteπor wheel dπving rotor according to a second embodiment of the present invention. Fig. 12 is an exploded cross sectional view of a structure of a motor assembly provided with an exteπor wheel dπving rotor according to a second embodiment of the present invention.

Fig. 13a illustrates a combined state of rotor yoke, a beaπng combination part, and a housing of a motor assembly provided with an exteπor wheel dπving rotor according to a second embodiment of the present invention.

Fig 13b is a cross sectional view of a stator yoke of a motor assembly provided with an exteπor wheel dπving rotor according to a second embodiment of the present invention.

Figs. 14a, 14b, and 14c illustrates an operation pπnciple of a motor assembly provided with an exteπor wheel dπving rotor according to a second embodiment of the present invention

Fig 15a is a cross sectional view of an embodiment of a permanent magnet of a

motor assembly provided with an exteπor wheel dπving rotor according to a second embodiment of the present invention.

Fig. 15b is a cross sectional view of an another embodiment of a permanent magnet of a motor assembly provided with an exteπor wheel dπving rotor according to a second embodiment of the present invention.

Fig. 16 is a cross sectional view of a structure of a linear motor according to a third embodiment of the present invention.

Fig. 17 is a cross sectional view of a fixed coil of a linear motor according to a third embodiment of the present invention. Figs. 18a, 18b, and 18c illustrates an operation pπnciple of a linear motor according to a third embodiment of the present invention.

Fig. 19 is a cross sectional view of an embodiment of a permanent magnet of a linear motor according to a third embodiment of the present invention.

Fig. 20 is a cross sectional view of an another embodiment of a permanent magnet of a linear motor according to a third embodiment of the present invention.

Fig. 21 is a plane view and partially zoomed cross sectional view of a fixed coil of a linear motor according to a third embodiment of the present invention.

Best Mode it is an aspect of the present invention to provide a single phase brushless and sensorless direct-current dynamo-type motor assembly provided with an inteπor wheel driving rotor of permanent magnetic flux circulating type, compπses: a rotor yoke 20 provided with an axial combining hole 23 in the middle and including permanent magnets 21 and 21' having an accommodation space for a core C on an inner wall thereof; a second aggregated protrusion 22 formed on both ends of the permanent magnets 21 and 21', respectively, on the rotor yoke 20; a stator yoke 30 surrounding peπpherals of the rotor yoke 20; a shaft assembly 50 provided with a shaft 51 axially combining with the axial combining hole 23 of the rotor yoke 20 and rotating; a first aggregated protrusion 34 protruding toward the rotor yoke 20 in the middle of the stator yoke 30; a third aggregated protrusion 35 protruding on both ends of the stator yoke 30 to face the second aggregated protrusion 22 and form a second transfer gap 42 in-between; and a core C being surrounded by the permanent magnets 21 and 21' with a distance as much as the length of an applying gap 40 while being fixed on the first aggregated protrusion 34 with a first transfer gap 41 of length as much as the thickness of a fixed coil 32, and being made as a fixed coil 32 winding around the outer peπpheral of the core yoke 31 made of ferromagnetic substance.

Additional aspects and advantages of the invention will be set forth in part in the

description which follows and, in part, will be obvious from the descπption, or may be learned by practice of the invention.

Mode for Invention To achieve purposes mentioned above, an inteπor wheel dnving type motor of a single phase brushless and sensorless direct-current dynamo-type motor assembly according to the present invention comprises: a rotor yoke 20 including an axial combining hole 23 in the center and a permanent magnet 21 having a core accommodation space on the inner wall; a second aggregated protrusion 22 formed around both ends of the permanent magnet 21 of the rotor yoke 20; a stator yoke 30 configured to surround the outer peripheral of the rotor yoke 20; a shaft assembly 50 provided with a shaft 51 combined with the axial combining hole 23 of the rotor yoke 20 and rotating; a first aggregated protrusion 34 protruding around the center of the stator yoke 30 toward the rotor yoke 20; a third aggregated protrusion 35 protruding from the opposite sides of the stator yoke 30 to face the second aggregated protrusion 22 and forming a second transfer gap 42 in-between; and a core C, which is made as a fixed coil 32 winding around the outer peripheral of the core yoke 31 made of ferromagnetic substance, fixed on the first aggregated protrusion 34 with the first transfer gap 41 of length as much as the thickness of a fixed coil 32 and surrounding and being distant as much as the length of an applying gap 40 by the permanent magnet 21.

Also, a method of dnving the motor according to the present invention compπses: a first step of forming a magnetic force of single polaπty from inner wall of the permanent magnet 21 formed on the rotor yoke 20; a second step of linearly transferring lines of magnetic force of the permanent magnet 21 from the whole area of the gap formed between the permanent magnet 21 and the fixed coil 32 to the core yoke C inside the fixed coil 32 provided on the core C; a third step of transferring the lines of magnetic force to the stator yoke 30 through the gap between the core C and the stator yoke 30; a fourth step of transferring the lines of magnetic force to the body of the rotor yoke 20 through the gap between the stator yoke 30 inducing concentration of the magnetic force along the body of the stator yoke 30 and the protrusion formed on the rotor yoke 20; a fifth step of circulating the lines of the magnetic force by returning the lines of the magnetic force toward the outer surface of the permanent magnet 21; and a sixth step of rotating the rotor yoke 20 using the magnetic force generated by implementing the first step through the fifth step, wherein the method of generating is implemented in a reversed order of the order descπbed above.

Hereinbelow, preferred embodiments of the present invention will be descπbed in reference with the attached drawings. The drawings are not in accordance with the exact

scale, and the same components will be referred by same numeral in each drawing.

The motor assembly according to the present invention is descπbed and distinguished as a first embodiment of an inteπor wheel dπving type motor assembly having an inner wheel as a dπving rotor, a second embodiment of an exteπor wheel dπving type motor assembly having an exteπor wheel as a dπving rotor, and a third embodiment of a linear motor having a linear movement. Hereinbelow, the first embodiment will be descπbed in reference with Figs. 5 through 10, the second embodiment will be descπbed in reference with Figs. 11 through 15, and the third embodiment will be descnbed in reference with Figs. 16 through 21. Fig. 5 is a cross sectional view of an inteπor wheel dπving type motor assembly which is a first embodiment according to the present invention. Fig. 6 is an exploded sectional view of a dynamotor assembly provided with an inteπor wheel dπving rotor according to the present invention.

Hereinbelow, the first embodiment according to the present invention will be descπbed mainly in reference with Figs. 5 and 6. The inteπor wheel type dynamotor shown as the first embodiment compπses a dπving body 10 having an overall round shape and formed with an axial combining hole 23 in the middle, and a shaft assembly 50 positioned on opposite sides of the dπving body 10 and being axially combined with the axial combining hole 23 of the dπving body 10. The driving body 10 includes: a rotor yoke 20 being provided with the permanent magnet 21, initially implementing a function of magnetic field path through which magnetic force of the permanent magnet 21 passes, and rotating by the generated force; and a stator yoke 30 formed with a core C made as a fixed coil 32 having a constant winding direction and flux linkage rotating direction winds a core yoke 31 inside, enhancing transferπng magnetic force generated from the permanent magnet 21 of the rotor yoke 20, and being provided with an external terminal 36 and an external electrode point 37 for electncally connecting a wire 36a formed on the fixed coil 32.

Fig 7A is a cross sectional view of a rotor yoke 20 of a dynamotor assembly provided with an inteπor wheel dπving rotor which is a first embodiment according to the present invention.

To explain the shaft assembly 50 in more detail, the shaft assembly 50 compπses the shaft 51 axially combined with the rotor yoke 20, the beaπng 52 ensuπng a proper rotating force of the shaft by reducing mechanical fπction, and the beaπng guide 53 as a housing accommodating such beaπng 52. Such a shaft assembly 50 is provided as a pair on left and πght of the rotor yoke 20 for keeping a constant distance and ensuπng a smooth moving between the stator yoke 30 and the rotor yoke 20. Also, a fastener such as a bolt 54 passes through each component of the shaft assembly 50 to couple to the

combimng hole 24 of the rotor yoke 20, a combination between the shaft assembly 50 and the rotor yoke 20 can be ensured, components such as the shaft 51 and the shaft assembly 50 are made of non-magnetic substance or diamagnetic substance. The beaπng 52 may be adopt one of ball beaπng, oilless slippery beaπng, not departing from the pπnciple of the present invention.

The rotor yoke 20 forms an inner space around the peπpheral of the center except for the axial combining hole 23. This is to provide a structure for accommodate the permanent magnet and the core C which will be descπbed later. Specifically, the permanent magnet 21 is preferably made of NdFeB and mounted on an inner wall of the rotor yoke 20, herein the inside thereof is formed as a hollow to accommodate the core C, forming a shape of doughnut or cylinder, and a structure of cross section is similar to a shape or "U" or horse shoes. Such a permanent magnet 21 is basically formed extending along an inner wall of the rotor yoke 20, but the permanent magnet 21 may be provided to be split into a proper number on the inner wall of the rotor yoke 20. Figs. 9A and 9B are modified examples of the permanent magnet 21' used in the first and second embodiments according to the present invention. The drawings show cross sections of an arrangement structure different from the permanent magnet 21 shown above.

The permanent magnets 21 and 21' are possibly formed continuously along the inner wall of the rotor yoke 20, as descπbed above, but it is also possible to be formed minimally within a range not interrupting a smooth path of the magnetic field applied perpendicularly toward the core C. Specifically, the permanent magnet 21' may be provided as 3 separate units perpendicularly along the inner wall of the rotor yoke 20, or as 2 separate units facing each other. Due to the minimal structure of the permanent magnet 21, perpendicular magnetic field can be ensured according to the present invention

An inner side and an outer side of the permanent magnet 21 take polaπty opposed to each other. As an example, if one side takes N polaπty, the other side takes S polaπty naturally and vice versa. To implement in real, the permanent magnet 21 according to the present invention is preferably made as a combination of two separate split halves of a horse shoe.

Both ends of the permanent magnet 21 provided on the rotor yoke 20 are formed with protrusions protruding outward with a certain length. This protrusion is called a second aggregated protrusion 22 in the present invention. (Although the protrusions are indistinguishable in the drawings, they exit on an end of the rotor yoke as miniscule protrusions.)

The second aggregated protrusion 22, which will be descπbed later, takes an

important function of magnetic path transferring the magnetic force as it faces a third aggregated protrusion 35 formed on the stator yoke 30.

Fig 7B is a cross sectional view of a combined state of the stator yoke 30 and the shaft assembly 50 of the dynamotor assembly provided with the inteπor wheel dπving rotor which is the first embodiment according to the present invention.

In reference with Fig. 7B, although the stator yoke 30 being made of ferromagnetic substance is not indicated with the reference numeral, it is fixed as one body by a beaπng guide additionally mounted on the outer side as shown in the drawings. Such an additional beaπng guide may be separately provided on inside and outside for a proper mechanical endurance of the stator yoke 30.

In reference with Figs. 5, 6, 7B, the stator yoke 30 is provided with the first aggregated protrusion 34 protruding toward a perpendicular center line of the rotor yoke 20. Herein the first aggregated protrusion 34 take a function of fixing/close-combimng between the fixed coil 32 and the wound core C. Besides, both ends of the first aggregated protrusion 34 are formed with a third aggregated protrusion 35 to correspond with the second aggregated protrusion 22. A gap between the second aggregated protrusion 22 and the third aggregated protrusion 35 is named as a second transfer gap 42.

Such a second transfer gap 42 has a disadvantage of having a greater loss as the distance of the gap gets bigger. However, without such a gap, a unnecessary mechanical friction may occur as the rotor yoke 20 rotates. So, to solve such a problem and improve ferromagnetic substance density, ferro-hquid may be additionally injected for positioning.

An end of the first aggregated protrusion 34 is formed with the core C including a core yoke 31 wound by the fixed coil 32. The core C has a gap against the first aggregated protrusion 34 with a distance as much as the thickness of the fixed coil 32. This gap is named as a first transfer gap 41.

The core yoke 31 is made of ferromagnetic substance, and functions as a body, or a bobbin, wound by the fixed coil 32. The fixed coil 32 passes through the center line of the first aggregated protrusion 34 to be electrically connected to a wire 36a connected to outer end of the stator yoke 30. Herein, each extended end of the wire 36a is connected to the external terminal plate 36 formed on the outer end of the stator yoke 30, and the external terminal plate 36 is formed with a plurality of external electrode points 37.

The outer peπpheral of the fixed coil 32 is wound by a coil guide 33 formed along the shape of the outer peπpheral. The coil guide 33 is positioned tightly in the inner space of the permanent magnet 21. Herein, a gap formed in shape of "U" along the arrangement of the permanent magnet 21 and the coil guide 33 is named as an applying gap 40.

Fig. 7C illustrates a plane view and a transparent cross sectional view of configuration of a core C used in the first and second embodiments according to the

present invention.

With reference to Fig. 1C, the core C supplied with the power in a single-phase method is formed of a shape similar to a doughnut. Although it is not shown in the drawing, the wire 36a electrically connected to the motor system provided with wiπng is connected to an external contacting point 37 provided on an external terminal plate 36 being provided on one side of the stator yoke 30 for inputting/outputting the power. Although it is not shown in the drawings, the wire 36a may be configured by extending a protrusion of an additional terminal plate formed inside the core C. The fixed coil 32 winding the core yoke 31 of ferromagnetic substance is wound tightly in one direction, so that it can function to provide power to rotate a shaft 51 of the motor and to collect electromotive force caused by generating.

Figs. 10a and 10b are plane views of another embodiments of the core C used for the first and second embodiments according to the present invention.

As shown in Figs. 10a and 10b, the core C may be provided with an internal terminal plate 32b for connecting modified coil along the peπpheral of the outer surface, and may be provided with a plurality of coil combining electrodes 32c or coil combining grooves 32a around the center so that they the fixed coil 32 can be combined with or wound on them. Accordingly, the core C according to the present invention may utilize a method of arranging coils in a state of split windings with a direct connection which is a already disclosed technology. By using such a method of arranging core C according to the additional embodiment of the present invention, more practical and convenient power supply can be realized and the present invention may be implemented more appropriately at the same time. In such a modified embodiment, it is possible that the wire 36a is configured as an extension of protrusion of the internal terminal plate 32b. In the modified embodiment, the fixed coil 32 takes a principle state of winding the core yoke 31 positioned inside according to the present invention. The fixed coil 32 provided as a plurality is wound to keep a same direction of transferring the power. Also, the core yoke 31 is included within the coil combining electrode 32c for individual configuration. With such a configuration, leakage current may be reduced so that πpple torque can be reduced and eventually the rotation of the shaft can be smoothed.

In reference with Figs. 8a, 8b, and 8c, the operation of the inteπor wheel dπving type motor according to the first embodiment of the present invention will be descπbed.

Fig 8a is a view illustrating a transferring path of the magnetic force generated from the dynamotor according to the present invention. Fig. 8b is a view illustrating a direction of force applied on the core C due to the magnetic force generated from the dynamotor according to the present invention. Fig. 8c is a view illustrating a direction of force applied on the rotor yoke 30 due to the magnetic force generated from the dynamotor

according to the present invention.

To realized the operation of the present invention, same surfaces of the permanent magnet 21 should be of same polarity not like the conventional technology which has multiple polarities of opposite polarities. Also, the outer surfaces of the core yoke 31 being wound with the fixed coil 32 according to transfer of the magnetic force of the applying gap 40 and the fixed coil 32 should be of same polarity.

The gaps 40, 41, and 42 according to the present invention function as a magnetic path. The applying gap 40 transfers the magnetic force of the permanent magnet 21 vertically to the core yoke 30 in order to generate a driving force practically with the magnetic force generated accordingly. The first transfer gap 41 is preferably configured to keep a minimum distance, and is a small gap with a distance corresponding to a thickness of the fixed coil 32 wound around the outer surface of the core yoke 31. It functions to transfer the magnetic force transferred to the core yoke 31 from the permanent magnet 21 to the first aggregated protrusion 34 again. Also, the rotor yoke 20 and the stator yoke 30 are made of ferromagnetic substance to successfully function as a magnetic path without leakage of magnetic force. Lastly, the second transfer gap 42 functions to transfer the magnetic force transferred along the body of the stator yoke 30 to the second aggregated protrusion 22 formed on a surface facing the third aggregated protrusion 35. Particularly, it is important for the second transfer gap 42 between the stator yoke

30 and the rotor yoke 20 to minimize the magnetic force loss by minimizing magnetic resistance. This means that the gap of the second transfer gap 42 is converged to near 0. However, if the second transfer gap 42 is zero, which is a case when the stator yoke 30 and the rotor yoke 20 are close tightly, the rotation of the rotor yoke 30 necessarily has to be limited. Accordingly, it is limited to reduce the gap of the second transfer gap 42.

Therefore, the gap of the second transfer gap 42 has to be determined to satisfy the condition that the stator yoke 30 and the rotor yoke 20 should not close too tight and the movement of the rotor yoke 20 should not be limited. Herein, the liquid ferromagnetic material which does not influence the rotor yoke 20 is needed to increase magnetic force density and reduce the generated magnetic resistance at the same time.

The present invention is configured to additionally use the ferro-fluid in the second transfer gap 42 between the second aggregated protrusion 22 and the third aggregated protrusion 35. However, it has been long since such a ferro-fluid was developed and used for the purpose of preventing leakage of the magnetic force or to concentrate the magnetic force. If the present invention is realized by applying this, it is possible to return the substantial amount of the magnetic force initially generated from the inner surface of the permanent magnet 21 to the other pole on the outer surface of the permanent magnet 21,

regardless of the gap of the second transfer gap 42 having a certain distance. Accordingly, it can be possible to realize the substance of the present invention that the magnetic force with a polaπty generated on the inner surface of the permanent magnet 21 passes through the core C vertically and circulates to the other pole on the outer surface of the permanent magnet 21 The ferro-fluid is deposited on the third aggregated protrusion 35 and it would be preferable that it is replaceable.

Through the operation of the gaps 40, 41, and 42, as shown in Fig. 6a, the path of transferring the magnetic force starting from the permanent magnet 21 according to the present invention is descπbed below. generation of the magnetic force with a polaπty from the inner surface of the permanent magnet 21 — > the applying gap 40 — > transferring to the core yoke C inside the fixed coil 32(transfer of the linear magnetic field from the whole area of the applying gap) --> the first transfer gap 41 --> the first aggregated protrusion 34 — > transferring to the third aggregated protrusion 35 inducing the concentration of the magnetic force along the body of the stator yoke 30 --> the second transfer gap 42(also possible to pass through the ferro-fluid) — > the second aggregated protrusion 22 — > transfer to the body of the rotor yoke 20 towar the outer surface of the permanent magnet 21 — > inflow to the outer surface of the permanent magnet 21 (the flow shown so far is for a case when the inner surface of the permanent magnet has N polaπty and the outer surface thereof has S polaπty, meanwhile the flow will be reversed in case when the polarities are reversed.)

Also, the magnetic path of the magnetic field generated from the motor assembly according to the present invention is descπbed below.

1. a direction of the magnetic field of the permanent magnet 21: As the applying gap 40 forming the gap on the inner surface of the permanent magnet 21 exists along the shape of the inner surface of the permanent magnet 21, vertical magnetic field lines toward the core C exist at each point of each applying gap 40, and the same polaπty is formed along the whole side area within the permanent magnet 21 at the same time. Contraπly, the opposite polaπty is formed on the core yoke 31 within the fixed coil 32.

2. a direction of the fixed coil 32: As outer current is induced into the fixed coil 32, due to the mutual reaction of a direction of the magnetic field of the permanent magnet and the fixed coil 32 wound in a direction perpendicular to the magnetic field of the permanent magnet, the direction of the magnetic field ranging from the permanent magnet 21 to the fixed coil 32 is same at all the point of applying gaps 40. Accordingly, the direction of the electromagnetic field generated in the fixed coil 32 is same/constant, likewisely, a movement direction within the applying gap 40 is formed constantly in a same direction at continuous points along the outer surface of the core C.

By the influence of the magnetic field, constant force occurs applying to each part

of core C and the inner surface of the permanent magnet 21 according to the fleming's rule. As shown in Figs. 8b and 8c, the movement directions of the rotor yoke 20 shown vertically seen cross sectionally oppose each other. Accordingly, the rotor yoke 20 rotates and the shaft assembly 50 linked to this also rotates, (in a case when the direction of inducing the current is reversed, the direction of the linked magnetic field is also reversed, which cause the direction of the rotation of the rotor to get reversed.)

In reference with Fig. 8b, the lower part of the core C, or the peπpheral of the first aggregated protrusion 34 is applied with a force opposing to the other parts. Herein, as the core C is fixed as one body to the first aggregated protrusion 34, the opposing force can be cancelled or ignored.

Additionally, by analogizing from the configuration and application descπbed above, as the rotation of the rotor yoke 20 linked to the rotation of the shaft 50 can generate the electromotive force according to the Fleming's rule, the motor according to the present invention has a meaning as a direct current generator(the present invention is referred as the " dynamotor" in such a perspective). That is, when applying external power, the present invention functions to generate power to rotate as a motor, and when applying external rotation force, the present invention functions as a single phase direct current generator.

If it is assumed that the present invention omits the core yoke 31, as it cannot induce the magnetic field lines, the flow of the magnetic field line from the inner surface of the permanent magnet 21 will not pass through the fixed coil 32 vertically, and eventually will return to the other pole on the outer surface of the permanent magnet 21. In such case, the generated force is too weak or cancelled to be near zero. That is, normal rotation of the rotor yoke 20will not be guaranteed, and the implementation of the motor according to the present invention will not be realized accordingly.

As a result, the principle configuration of the motor according to the present invention is that the core yoke 31 of ferromagnetic substance exists inside the fixed coil 32, and the flow of the magnetic field of the permanent magnet 21 is induced due to the ferromagnetic mateπal, so that the magnetic field line of same polaπty generated from the inner surface of the permanent magnet 21 passes through the applying gap 40 and the fixed coil 32 disposed outside the core yoke 31. As a result, maximized attractive/repulsive force can occur at the applying gap 40, which becomes a source of driving the rotor yoke 20.

As the descπption on the inteπor wheel dnving type motor according to the present invention is completed, hereinbelow, the second embodiment of the exteπor wheel dnving type motor according to the present invention will be descnbed in reference with Figs 11 through 15.

The exteπor wheel dnving type motor which is the second embodiment according to the present invention has a similar technical and operational principle with the intenor wheel dnving type motor except for the structural difference to form the exteπor wheel. Accordingly, redundant descπption will be omitted. Fig. 11 is a cross sectional view on a schematics of the exteπor wheel dnving type motor assembly which is the second embodiment of the present invention. Fig 12 is an exploded cross sectional view of the dynamotor assembly provided with the exteπor wheel dnving rotor which is the second embodiment of the present invention.

In reference with Figs. 11 and 12, the configuration of the present invention will be descnbed schematically The extenor wheel dnving type motor assembly according to the present invention compnses' a stator yoke 30 shaped symmetπcal honzontally and vertically from a center line of the shaft 50, a rotor yoke 20 provided on the outer surface of the stator yoke 30 and being axial-combined to rotate on the both ends of the shaft 50 and being provided with a permanent magnet 21 which is a source of generating magnetic force, a beanng combination part 55 being combined to a combining hole 26 formed on the both sides of the rotor yoke 20; and a housing 60 being positioned on the outside of the both sides of the rotor yoke 20 and surrounding the rotor yoke 20.

That is, the rotor yoke 20 functions as a source of the magnetic path which is a path of the magnetic force of the permanent magnet 21 by being provided with the permanent magnet 21, and is a subject of rotating movement which is a basis of dnving force. The stator yoke 30 plays the same role with the center fixing axis. The stator yoke 30 is wound with the fixed coil 32 having a certain direction of winding and flux linkage rotation on the outside thereof, and is formed with the core C including the core yoke 31 formed on the opposing side of the applying gap 40 in order to induce the transfer of the magnetic force of the permanent magnet 21 of the rotor yoke 20. The housing 60 surrounds the outer surface of the rotor yoke 20 to rotate in accordance with the rotation of the rotor yoke 20. The bearing combination part 55 is combined to one side of the shaft 56 formed on the stator yoke 30 to enhance mechanical conveniency.

Fig 13a is a cross sectional view on a combining state of the rotor yoke 20, the beanng combination part 55, and the housing 60 of the dynamotor assembly provided with the extenor wheel dnving rotor which is the second embodiment of the present invention.

In reference with Figs. 11 through 13a, the rotor yoke 20 according to the present invention is basically formed as a cyhnder(Although other shapes other than a cylindncal shape can be utilized, it will be descnbed based on the cylindncal shape), and is provided with an inner space to accommodate the core C which will be descnbed later. An inner wall of one side on a cross section of the stator yoke 20 (shown vertically in Fig. 3) has a shape similar to a horse shoes or "U" The permanent magnet having a shape of a horse

shoes along the shape of the inner wall is provided.

The both ends of the outer wall of the rotor yoke 20 are provided with holes passing through the center thereof for axial combination with the shaft 56 of the stator yoke 20, and formed with the combining hole 26 protruding outward or in a direction toward the housing 60 so that the shaft 56 and the bearing combination part 55 are inserted into it.

The bearing combination part 55 consists of a bearing 57 and a bearing guide 58 accommodating the bearing 57 in order to guarantee a smooth and efficient rotation of the rotor yoke 20. A combining hollow 56a of the housing 60 is provided on the outside of the combining hole 26 of the rotor yok 30 so that the combining hole 26 is inserted into the combining hollow 56a of the housing 60. The bearing combination part 55 is provided as one pair on both ends between the rotor yoke 20 and the stator yoke 30 for keeping a constant distance between the stator yoke 30 and the rotor yoke 20 and for a smooth movement of the rotor yoke 20. The bearing 57 and the bearing guide 58 consisting the bearing combination part 55 are made of nonmagnetic or diamagnetic substance. The ball bearing, the oilless bearing, or the sliding bearing may be employed as the bearing 57 within the scope of the present invention.

The housing 60 is to ensure mechanical endurance of the motor according to the present invention by surrounding the rotor yoke 20, and has a structure symmetric to left and right. A protrusion 59 formed on one side thereof is combined to the combining hole 24 of the other side to endure the firm combining relation to the housing 60 and to form a completed motor assembly according to the present invention.

Fig. 13b is a cross sectional view of the stator yoke 30 of the dynamotor assembly provided with the exterior wheel driving rotor according to the present invention.

In reference with Fig. 13b, the stator yoke 30 is made of soft ferromagnetic substance, and provided on the center of the shaft 56. Herein, the shaft 56 functions as a fixed axis, and the bearing combination part 50, the rotor yoke 20, and the housing 60 are combined sequentially on both ends of the shaft 56.

The core yoke 31 is also made of ferromagnetic substance, and at the same time, functions as a body wound by the fixed coil 32, or a bobbin. The fixed coil 32 passes through the center line of the first aggregated protrusion 34 and extends to the center of the stator yoke 30, and reaches middle point of the shaft 56, where the fixed coil 32 gets bent along a longitudinal direction of the both ends of the shaft 56. Herein, the fixed coil 32 is electrically connected to the wire 36a formed up to the end of the shaft 56. Each ends of the wire 36a, or both ends of the shaft 56 are formed with the external terminal plate 36 for inputting/outputting the power, wherein the external terminal plate 36 is formed with a plurality of external electrode points 37.

Components of the second embodiments according to the present invention shown

in Figs 11 through 13 are not descπbed as it is redundant with the first embodiment. The first embodiment can be referred for such descπption.

An operation of the exteπor wheel dπving type motor which is the second embodiment of the present invention is descπbed in reference with Figs. 14a, 14b, and 14c

Fig 14a illustrates schematically a path of transferring the magnetic force generated in the exteπor wheel dπving type motor which is the second embodiment of the present invention Fig. 14b illustrates schematically a direction of force applied to the core C caused by occurπng magnetic field of the exterior wheel dπving type motor which is the second embodiment of the present invention. Fig. 14c illustrates schematically a direction of force applied to the rotor yoke 20 caused by the magnetic field generated in the exteπor wheel dnving type motor which is the second embodiment of the present invention

A descπption on the specific operation and a direction of the path of the generated magnetic field will be omitted as they are same as the first embodiment. That is, although the operation of the exteπor wheel dπving type motor according to the second embodiment of the present invention is not descπbed in this specification, it is obvious that they can be implemented in accordance with the drawings, the configuration, and the operation of the first embodiment.

Figs. 16 through 21 depicts a linear motor which is a third embodiment according to the present invention. As the basic function and operation of the linear motor is same as the first and second embodiment, hereinbelow the linear motor will be descπbed.

Fig. 16 is a cross sectional view of a single phase linear motor which is the third embodiment of the present invention.

To descπbe the configuration of the present invention schematically in reference with Fig. 16, the linear motor according to the present invention compπses: a stator 30' having shape of a base plate and being provided with a guide rail 38 on both ends and with a core C protruding on the middle toward a mover 20'; and a mover 20' being provided on an upper part of the stator 30' and moving by generation of the force based on the magnetic force and being provided with the permanent magnet 21 being a source of generating magnetic force.

That is, the mover 20' is a component corresponding to the rotor yoke 20 in the first and second embodiments, functions as a magnetic path which is a path of magnetic force of the permanent magnet 21 as one side of the applying gap 40 is provided with the permanent magnet 21, and is a main body moving linearly along the guide rail. The stator 30' is a component corresponding to the stator yoke 30 of the first and second embodiments. The stator 30' is wound on its outside with the fixed coil 32 having a certain direction of winding and flux linkage rotation, and is formed with the core C including

the core yoke 31 formed on the opposite side of the applying gap 40, so that it can induce the transfer of the magnetic force of the permanent magnet 21 provided on the mover 20'. As the guide block 29 of the mover 29' and the guide rail 38 of the stator 30' are combined tightly in convexo-concave manner, a moving direction of the mover 20' can be guided not to deviate outside as the mover 20' moves linearly.

In reference with Fig. 16, the mover 20' according to the present invention has a middle part formed in a halve ellipse shape (although shapes other than ellipse shape can be employed, the present invention will be described on a basis of the ellipse shape), and has both ends being bent perpendicularly and forming a horizontal plate 28 being extending longitudinally and being parallel to the stator 30' so that it can provide an inner space where the core C of the stator 30' can be positioned within. An inner wall of the center part of the cross sectional structure of the stator 30' is shaped similar to a horse shoes or "U". Herein, the permanent magnet 21 having a shape similar to a horse shoes along the inner wall is provided. A lower part of the horizontal plate 28 of the mover 20' is formed with a guide block 29' combining with the guide rail 38 of the stator 30' in a convexo-concave or railing manner, so that the mover 20' can move linearly, not deviating outside on a basis of combination of the guide rail 38 and the guide block 29. The guide rail 38 and the guide block 29 are preferably made of nonmagnetic or diamagnetic substance in order not to influence the deformation of the magnetic path for generating force.

The permanent magnet 21 having same configuration as the first and second embodiments is basically formed extending evenly along the inner wall of the mover 20' in shape of "U". However, the permanent magnet 21 may be provided as a plurality on the inner wall, not being limited to the basic form. Figs. 19 and 20 are modified examples of the permanent magnet 21' according to the present invention, which shows a plane view of arrangement and structure of the permanent magnet 21 different from the permanent magnet described above.

The permanent magnets 21 and 21' may be formed evenly along the inner wall of the mover 20'. However, it can be provided as 3 splitted units perpendicularly along the inner wall of the mover 20' or as 2 separate units facing each other, within a range to ensure a moving path of the magnetic force applying perpendicularly toward the core C, as shown in the drawings. According to the configuration of the permanent magnet 21', it will ensure the mobility of the perpendicular magnetic force. A description on general specifics of the permanent magnet included in the third embodiment is same as the description of the first and second embodiments.

Both ends of the permanent magnet 21 provided on the mover 20' are formed with protrusions protruding outwardly in a constant length(not shown conspicuously in the

drawings). This protrusion is named as the second aggregated protrusion 22 in the present invention and its function is same as descπbed in the first and second embodiments.

The second aggregated protrusion 22 functions as a magnetic path to build a structure of magnetic circuit by being faced with the third aggregated protrusion 35 of the stator 30'.

The stator 30' according to the present invention functions as a fixed base plate by being provided on a flat area such as ground. The stator 30' is made of soft ferromagnetic substance and is formed with the guide rail 38 on the top of the both ends thereof to combine with the guide block 29. Also, the stator 30' is provided with the first aggregated protrusion 34 protruding toward the vertical center line of the mover 20'. The first aggregated protrusion 34 functions to combine tightly with the core C wound with the fixed coil 32 which will be descπbed later.

Additionally, both ends of the first aggregated protrusion 34 are formed with the third aggregated protrusion 35 to face the second aggregated protrusion 22. The gap between the second aggregated protrusion 22 and the third aggregated protrusion 35 is named as the second transfer gap 42.

The second transfer gap 42 profoundly contains a disadvantage that the magnetic loss becomes greater as the distance of the gap becomes bigger. However, if the distance of this gap is removed or minimized to get πd of such a disadvantage by contacting respective protrusions 22 and 35, unnecessary fπction may occur on the contacting area as the mover 30' moves linearly. Accordingly, in order to solve such a problem, the ferro- fluid can be injected to improve magnetic density

Components not descπbed in the other drawings may be understood in reference with descπptions on the first and second embodiment of the present invention.

Fig. 17 is a perspective view illustrating the configuration of the core C included in the third embodiment of the present invention.

In reference with Fig. 17, the core C supplying power in single phase method is formed in shape similar to a doughnut or ellipse, when seen in a cross section, and is supposed to be extending in a longitudinal direction.

Fig. 21 is a plane view and a partial exploded cross sectional view illustrating different embodiment of the core C according to the present invention.

As shown in Fig. 21, the core C according to the present invention can be provided in a split winding state. In other words, the fixed coil 32 is wound separately along a longitudinal direction of the core C. An inner side of the coil windings is provided with the fixed yoke 31. According to such embodiments, the present invention can be implemented more appropπately using practical and efficient generating of electπc power.

In other words, in such modified embodiments, the fixed coil 32 functions as a bobbin being positioned inside and keep a basic structure of winding the core yoke 31. The fixed coil 32 being provided as a plurality is wound to keep a same direction of power transfer. With such configuration, power leakage can be reduced and efficient power supply can be kept to enhance a smooth power supply.

A descπption on the operation of a linear motor which is the third embodiment of the present invention will be descπbed below, in reference with Figs. 18a, 18b, and 18c

Fig. 18a illustrates a transferring path of the magnetic field line generated in the linear motor according to the present invention. Fig. 18b illustrates a direction of the power applied to the core C by the generated electromagnetic field of the linear motor according to the present invention. Fig. 18c illustrates a direction of the power applied to the mover 20' by the electromagnetic field generated in the motor according to the present invention, or a direction of thrust.

As a descπption on the specific operation and a direction of the magnetic path of the generated magnetic field is same as the description of the first and second embodiments, it will be omitted.

Due to the influence of the magnetic field shown in Fig. 19, each core C and inner surface of the permanent magnet 21 are applied with the force according to the Fleming's rule Accordingly, as shown in Figs. 18b and 18c, the mover 20' is moved by the generated thrust. (in a case where a direction of the current input is reversed, a direction of the linked electromagnetic field is reversed, which causes a direction of movement of the mover is reversed too.)

In reference with the Fig. 19, the lower part of the core C, or a portion around the first aggregated protrusion 34 is applied with a force opposing to the other portions. Herein, as the core C is fixed as one body to the first aggregated protrusion 34, such oppostion force can be cancelled or ignored.

The operation of the linear motor according to the third embodiment of the present invention can be obviously implemented in accordance with the drawings and the descπbed configuration and operation of the first and second embodiment of the present invention.

As descπbed above, although the configuration and operation of the single phase brushless and sensorless direct-current dynamo-type motor assembly according to the present invention was descπbed in reference with the drawings, those are only examples which does not limit the scope of the present invention. Vaπous modifications and changes may be employed within the scope not departing from the pπnciple of the present invention.

Although a few embodiments of the present invention have been shown and

described, the preferred embodiments described so far should be understood as an examples. In other words, it will be appreciated by those skilled in the art that changes may be made in these aspects without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.