ES2652261T3 - Motor and its permanent magnet rotor - Google Patents

Abstract

A rotor to rotate in one direction in an engine, the rotor comprising: a first and a second cavities (608, 618) to contain a first and second permanent magnets (110a, 110b, 110d, 110e) a first and second barriers (606, 616) of flow to communicate with the respective ends of the first and second cavities closest to an outer circumferential surface of the rotor (104, 904); and respective ribs (352, 952) formed between the outer circumferential surface of the rotor (104, 904) and the first and second flow barriers (606, 616) in which a first end of each of the ribs (352, 952) on an upstream side in a direction of rotation of the rotor (104,904) is wider than a second end of the rib (352,952) on a side downstream in the direction of rotation of the rotor (104,904), characterized in that the first and the second cavities (608, 618) are arranged in parallel, in which one of the first and second cavities (608, 618) is arranged to be closer to the outer circumferential surface of the rotor (104, 904) than the other of the first and second cavities (608,618).

Description

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DESCRIPTION

Motor and its permanent magnet rotor

The following description refers to a motor (electric motor) that converts electrical energy into kinetic energy and, more particularly, to a permanent magnet motor in which permanent magnets are coupled to a rotor.

Motors are devices for converting electrical energy into kinetic energy. Various types of engines classified according to their structure and function are used throughout the industry. One of these various types of motors is a radius type motor in which permanent magnets are used in a rotor and arranged in the form of radii. In the radius type motor, local demagnetization can occur at the ends of permanent magnets. This local demagnetization is responsible for degrading the performance of the radio type engine.

EP 1973217 A2 (D1) discloses a lamination for the permanent magnet motor in which the magnets are placed in a V-shape with arched spaces at both ends of the magnet holes provided to prevent flow leakage.

Therefore, a scheme is desired to minimize local demagnetization (or improve a demagnetization resistant force) in the radio type engine to improve the performance of the radio type engine.

Therefore, one aspect of the present disclosure is to minimize demagnetization to improve a demagnetization resistant force in a permanent magnet motor without increasing the thickness of each permanent magnet as well as a distance between each permanent magnet and a stator.

In the description that follows, additional aspects of the disclosure will be set forth in part and, in part, will be obvious from the description, or may be learned through the practice of the disclosure.

In accordance with one aspect of the present disclosure, a rotor is defined according to claim 1. In the rotor, each of the ribs is formed elongated in a circumferential direction of the rotor.

In the rotor, the width of one end of each of the ribs is sharply reduced in the direction of rotation, and the width of the other end of each of the ribs is smoothly reduced in the direction of rotation.

In the rotor, each of the flow barriers is configured so that a width of one end thereof on an upstream side in a direction of rotation of the rotor is narrower than a width of the other end thereof in a downstream side in the direction of rotation.

In the rotor, the cavities, the flow barriers and the ribs are continuously formed from a rotation shaft towards the outer circumferential surface of the rotor.

In the rotor, the cavities are configured such that: a first cavity to contain a first permanent magnet and a second cavity to contain a second permanent magnet constitute a pole; and the first and the second cavity are arranged radially around a rotation shaft of the rotor towards the outer circumferential surface.

In the rotor, the first and second cavity have a V-shape in which they extend from the center of the rotor rotation shaft towards the outer circumferential surface.

According to one aspect of the present disclosure, a rotor of a motor rotates in both directions and includes: cavities configured to contain magnets; flow barriers configured to communicate with the first ends of the cavities and formed adjacent to an outer circumferential surface of the rotor; and nerves formed between the outer circumferential surface of the rotor and the flow barriers. Each of the ribs is elongated in a direction of rotation of the rotor and has a shape in which the widths of its opposite ends are wider than that of an intermediate portion thereof.

In the rotor, each of the flow barriers is configured so that a width of one end thereof on an upstream side in a direction of rotation of the rotor is narrower than a width of the other end thereof in a downstream side in the direction of rotation.

In the rotor, the cavities, the flow barriers and the ribs are continuously formed from a rotation shaft towards the outer circumferential surface of the rotor.

In the rotor, the cavities are configured such that: a first cavity to contain a first permanent magnet and a second cavity to contain a second permanent magnet constitute a pole; and the first and the second cavity are arranged radially around a rotation shaft of the rotor towards the outer circumferential surface.

In the rotor, the first and second cavity have a V-shape in which they extend from the center of the tree

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Rotation of the rotor towards the outer circumferential surface.

According to one aspect of the present disclosure, an engine includes: a stator in which the coils are wound; and a rotor rotatably installed inside the stator and having at least one magnet contained therein. The rotor includes: cavities configured to contain the magnets; flow barriers configured to communicate with the first ends of the cavities and formed adjacent to an outer circumferential surface of the rotor; and nerves formed between the outer circumferential surface of the rotor and the flow barriers. Each of the ribs is configured so that a width of one end thereof on an upstream side in a direction of rotation of the rotor is wider than that of the other end thereof on a side downstream in the direction of rotation.

These and / or other aspects of the disclosure will be apparent and will be more readily appreciated from the following description of the embodiments, taken together with the accompanying drawings, of which:

Figure 1 is a view illustrating an assembly of a stator and a rotor of an engine according to an embodiment of the present disclosure;

Figure 2 is an exploded perspective view of the stator and motor rotor in accordance with an embodiment of the present disclosure;

Figure 3 is a top view of the stator and rotor of the motor according to an embodiment of the present disclosure;

Fig. 4 is a view illustrating the magnetization directions of the plurality of permanent magnets that are magnetized in the motor rotor according to an embodiment of the present disclosure; Figure 5 is a view illustrating a concept of how the magnetic flux of the plurality of permanent magnets is concentrated in a core of magnetic flux concentration;

Figure 6 is a view illustrating detailed shapes of the cavities and flow barriers formed in the motor rotor in accordance with an embodiment of the present disclosure;

Figure 7 is a view illustrating an asymmetric structure of the pair of flow barriers illustrated in Figure 6; Figure 8 is a view illustrating shapes of the rotor ribs in the engine according to an embodiment of the present disclosure;

Figure 9 is a top view of a stator and a rotor of an engine according to an embodiment of the present disclosure;

Figure 10 is a view illustrating detailed shapes of cavities and flow barriers formed in the motor rotor in accordance with an embodiment of the present disclosure;

Figure 11 is a view illustrating an asymmetric structure of the pair of flow barriers illustrated in Figure 10;

Fig. 12 is a view illustrating shapes of the rotor ribs in the engine according to an embodiment of the present disclosure;

Figure 13 is a top view of a stator and rotor of an engine according to an embodiment of the present disclosure;

Figure 14 is a view illustrating detailed shapes of cavities and flow barriers formed in the motor rotor in accordance with an arrangement of the present disclosure;

Figure 15 is a view illustrating a symmetrical structure of the pair of flow barriers illustrated in Figure 14; Figure 16 is a view illustrating shapes of the rotor ribs in the motor according to an arrangement of the present disclosure;

Figure 17 is a top view of a stator and rotor of an engine according to an arrangement of the present disclosure;

Figure 18 is a view illustrating a shape of the rotor nerve in the motor according to an arrangement of the present disclosure;

Figure 19 is a top view of a stator and a rotor of an engine according to an arrangement of the present disclosure;

Figure 20 is a view illustrating a shape of the rotor nerve in the motor according to an arrangement of the present disclosure;

Figure 21 is a top view of a stator and rotor of an engine according to an arrangement of the present disclosure;

Figure 22 is a view illustrating shapes of the rotor ribs in the motor, as illustrated in Figure 21, in accordance with an arrangement of the present disclosure;

Figure 23 is a view illustrating a result of the demagnetization analysis when the nerve shapes of a unidirectional rotary motor are symmetrical;

Fig. 24 is a view illustrating a result of the demagnetization analysis when the unidirectional rotary motor nerves (rotary motor counterclockwise) according to an embodiment of the present disclosure are asymmetric;

Figure 25 is a view illustrating the results of the analysis of the counter-electromotive forces without load and of the harmonics of the bi-directional rotary motor according to an embodiment of the present disclosure and a comparative model; Y

Figure 26 illustrates load lines at the ends of the permanent magnets of the bidirectional rotary motor according to an embodiment of the present disclosure and the comparative model.

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Reference will now be made in detail to the embodiments of the present disclosure, the examples of which are illustrated in the accompanying drawings, in which the same reference numbers refer to similar elements throughout.

Figure 1 is a view illustrating an assembly of a stator and a rotor of an engine according to an embodiment of the present disclosure. As illustrated in Figure 1, a cylindrical rotor 104 is rotatably installed within a cylindrical stator 102. There is a gap between an inner surface of the stator 102 and an outer surface of the rotor 104 so that the rotor 104 can rotate smoothly within the stator 102 without contact. A rotation shaft 108 is provided within the rotor 104. The rotor 104 rotates around the rotation shaft 108.

Stator 102 and rotor 104 may be protected by a box (not shown). The rotation shaft 108 is fixed to the rotor 104 in the center of the rotor 104. In this way, a rotational force of the rotor 104 is transmitted to the rotation shaft 108, and thus the rotor 104 and the rotation shaft 108 rotate together. The rotor 104 and the rotation shaft 108 can rotate in a single direction (for example, clockwise).

In Figure 1, a plurality of teeth 112 are formed on the inner surface of the stator 102. The plurality of teeth 112 is configured such that an inner wall of the stator 102 protrudes a predetermined length towards the rotor 104. The plurality of teeth 112 are all arranged at equal intervals. Between the adjacent teeth (112) a space called slot 114 is defined. The coils 116 are wound around the plurality of teeth 112, respectively. The slots 114 serve as spaces for keeping the coils 116 wound around the respective teeth 112. In the stator 102 illustrated in Figure 1, nine teeth 112 and nine slots 114 are provided. The number of teeth 112 and the number of slots 114 They are not limited to nine, and can be changed according to the desired characteristics (for example, the number of poles) of the motor.

A plurality of permanent magnets 110 is contained in the rotor 104. The plurality of permanent magnets 110 may be contained radially so that it is symmetrical with respect to the rotation shaft 108 and so that it is oriented to an outer circumferential surface of the rotor 104. In the rotor 104 of the motor according to an embodiment of the present disclosure, Six pairs of permanent magnets 110 are contained as illustrated in Figure 1. The rotor 104 is formed with a plurality of cavities 208 (see Figure 2) to contain the permanent magnets and a plurality of flow barriers 106. Aqm, each flow barrier 106 may be air. In addition, the flow barriers 106 can be filled with a non-magnetic material. Next, a structure of rotor 104 will be described in detail with reference to Figures 2 and 3.

Figure 2 is an exploded perspective view of the stator and motor rotor according to an embodiment of the present disclosure. As illustrated in Figure 2, the rotor 104 is formed by stacking a plurality of rotor cores 202. Each of the plurality of rotor cores 202 is formed with the plurality of cavities 208 to contain permanent magnets 110 and a plurality of rivet holes 204. When the plurality of rotor cores 202 are stacked in an aligned state, the spaces, that is, the cavities 208, are formed, in which the permanent magnets 110 can be contained. Furthermore, when the plurality of rotor cores 202 are stacked in an aligned state, spaces are formed, that is, the rivet holes 204, in which the rivets 206 can be inserted. When the rivets 206 are fastened after passing through of the rivet holes 204, the plurality of rotor cores 202 can be mechanically coupled.

Figure 3 is a top view of the stator and rotor of the motor according to an embodiment of the present disclosure. As described above with reference to Figures 1 and 2, the coils 116 are wound around the nine teeth 112 formed in the stator 102. Next, a structure will be described in which the coils 116 are wound around the teeth 112 of stator 102 using two adjacent teeth 112a and 112b as an example. That is, as illustrated in Figure 3, when the coil 116a is wound around the tooth 112a, the wound coil 116a occupies the left and right spaces (grooves) of the tooth 112a. Also, when the coil 116b is wound around the tooth 112b, the wound coil 116b occupies the left and right spaces (grooves) of the tooth 112b.

The six pairs of, that is, the twelve, permanent magnets 110 are contained in the rotor 104 in a radial form so that they are symmetrical with respect to the rotation shaft 108 and so that they are oriented towards the outer circumferential surface of the rotor 104. Due Since the plurality of permanent magnets contained in the radial form in this way is in the form of radii, the concentrated flow type motor illustrated in Figures 1 to 3 is also known as the radius type motor. A pair of permanent magnets 110 constitutes a pole. Therefore, the motor illustrated in Figures 1 to 3 is a motor with a 6-pole rotor 104. A portion indicated by reference number 350 in Figure 3 denotes a portion corresponding to a pole at stator 102 and rotor 104. As can be seen from the portion indicated by reference number 350, a pair of magnets 110 permanent has a "V" shape in which they extend from the rotation shaft 108 to an outer circumference of the rotor 104. The number of permanent magnets 110 is not limited to twelve (six pairs), and can be changed to obtain the desired characteristics (for example, the number of poles) of the motor.

In the state in which the plurality of permanent magnets 110 are inserted in the rotor 104, the flow barriers 106 are formed at opposite ends of each permanent magnet 110. In addition, a rib 352 is formed between the outer circumferential surface of the rotor 104 and the flow barriers 106. The forms of flow barriers and

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The nerve in the motor is in close connection with the generation of an electromagnetic excitation force, the formation of a magnetic flux path, an increase / decrease in the demagnetization force and so on. A procedure to minimize demagnetization, that is, to maximize demagnetization resistant force, in the permanent magnet includes a procedure to increase the thickness of the permanent magnet or a procedure to increase the distance between the permanent magnet and the stator. The former may be responsible for an increase in the cost of production of the motor because a larger permanent magnet is required, and the latter may be responsible for an increase in the volume of the rotor (or motor) because a wider space is required for the disposition of the permanent magnet. In the motor according to the realization of the present disclosure, a rotor nerve structure will be proposed to minimize demagnetization in the permanent magnets of the motor without increasing the sizes of the permanent magnets or the volume of the motor.

Figures 4 and 5 are views illustrating the magnetization and magnetic flux concentration of the plurality of permanent magnets. Figure 4 is a view illustrating the magnetization directions of the plurality of permanent magnets 110 in the rotor 104. Figure 5 is a view illustrating a concept of how the magnetic flux of the plurality of permanent magnets 110 is concentrated in a 428 core of magnetic flux concentration.

The magnetization directions of the permanent magnets of Figure 4 will be described in detail below. The plurality of permanent magnets 110 can be divided when two of them are opposite each other through an axis d and two of them are opposite each other through an axis q. Permanent magnets 110 that are opposite each other across the q axis are magnetized at equal polarities between sf (N and N poles or S and S poles), while permanent magnets 110 that are opposite each other across sf through the d axis are magnetize at different polarities between sf (poles N and S or poles S and N).

For example, assuming that a combination of a first and second permanent magnets 110a, 110b adjacent to the d-axis forms a first combination 110C of permanent magnets and that a combination of a second and third permanent magnets 110b, 110d adjacent to the q-axis form a second combination 110f of permanent magnets, the second permanent magnet 110b of the second and third permanent magnets 110b and 110d adjacent to the q axis can be magnetized so that the poles S and N are arranged sequentially in a circumferential direction clockwise, and the third Permanent magnet 110d can be magnetized so that the N and S poles are arranged sequentially in the circumferential direction clockwise. In addition, the first and second permanent magnets 110a and 110b located on both sides of the d-axis can be magnetized so that the poles S and N are arranged sequentially in the circumferential direction clockwise.

Figure 6 is a view illustrating detailed shapes of the cavities and flow barriers formed in the motor rotor in accordance with an embodiment of the present disclosure. In detail, Figure 6 illustrates a structure of a portion of the rotor 104 which is a circular sector 350 indicated by dashed dashed lines in Figure 3, that is, structures of a pair of permanent magnets constituting a pole and its surroundings. In Figure 6, for a detailed description of the cavities and flow barriers, new reference numbers are given to the cavities and the flow barriers. In Figure 6, the cavities and flow barriers to which the new reference numbers are given include a first cavity 608, a second cavity 618, a first flow barrier 606, a second flow barrier 616, a third barrier 610 flow and a fourth flow barrier 620.

Figure 6 (A) illustrates a state in which permanent magnets (for example, 110 of Figure 2) are not contained in cavities 608 and 618, and Figure 6 (B) illustrates a state in which magnets permanent (for example, 110 of Figure 2) are contained in cavities 608 and 618. In Figure 6 (B), the permanent magnets 110 contained are indicated by a shading pattern.

As illustrated in Figure 6 (A), the first flow barrier 606, the first cavity 608 and the third flow barrier 610 are continuously formed on the right side of the axis q from the outer circumferential surface towards the central axis of the rotor 104. In Figure 6 (A), the first flow barrier 606, the first cavity 608 and the third flow barrier 610 are divided by broken lines, which is a virtual division to distinguish them.

The second flow barrier 616, the second cavity 618 and the fourth flow barrier 620 are continuously formed on the left side of the axis q from the outer circumferential surface towards the central axis of the rotor 104. In Figure 6 (A), the second flow barrier 616, the second cavity 618 and the fourth flow barrier 620 are divided by broken lines, which is a virtual division to distinguish them.

In the engine according to an embodiment of the present disclosure, two of the flow barriers formed on the left and right sides of the axis have a structure in which the shapes and positions thereof are asymmetrical. For example, the first flow barrier 606 and the second flow barrier 616 illustrated in Figure 6 (A) and Figure 6 (B) have a structure in which the shapes and positions thereof are asymmetric. This is in consideration of a rotation direction of the rotor 104. In the engine according to an embodiment of the present disclosure, the asymmetric structure of the first flow barrier 606 and the second flow barrier 616 is established in view of the In which case the rotor rotates clockwise in the top view as illustrated in Figure 3. This asymmetric structure of the two flow barriers will be described in detail below with reference to Figure 7.

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Figure 7 is a view illustrating the asymmetric structure of the pair of flow barriers illustrated in Figure 6. To aid in the understanding, the flow barriers and the cavities of the different adjacent poles between each other through the axis d are illustrated in Figure 7. For example, the first flow barrier 606, the first cavity 608 and the third flow barrier 610 of Figure 7 are elements that constitute a part of a first pole, and the second flow barrier 616, the second cavity 618 and the fourth flow barrier 620 are elements that constitute a part of a second pole adjacent to the first pole.

In Fig. 7, in comparison with the positions of the first and second cavity 608 and 618 to contain the permanent magnets 110, the second cavity 618 is closer to the outer circumferential surface of the rotor 104 than the first cavity 608. By therefore, there is a position difference indicated by the reference number 732 along the axis d between the first cavity 608 and the second cavity 618. However, the first cavity 608 has the same length as the second cavity 618. The Difference in position between the first cavity 608 and the second cavity 618 serves to make the positions of the permanent magnets 110 contained in the first and second cavity 608 and 618 different. Due to the difference in position, it is possible to reduce the demagnetization that occurs in permanent magnets.

The first flow barrier 606 connected to the first cavity 608 is formed elongated at one end of the first cavity 608 (at a terminal end oriented to the outer circumferential surface of the rotor 104) in a circumferential direction of the rotor 104 such that its width is gradually reduced at a soft angle and then at a relatively acute angle. In other words, the first flow barrier 606 illustrated in Figure 7 may have a cradle shape that is elongated in the circumferential direction of the rotor 104. In this cradle shape, a portion 712 of a stator-oriented contour 102 is gently inclined, and the other portion 714 is relatively inclined. In the first flow barrier 606, the portion 712 having the gentle inclination is formed downstream in the direction of rotation of the rotor 104, and the other portion 714 having the pronounced inclination is formed upstream in the direction of rotation of the rotor 104. That is, when the rotor 104 rotates, the portion 712 which has the gentle inclination at the first flow barrier 606 is followed by the portion 714 which has a pronounced inclination.

The second flow barrier 616 connected to the second cavity 618 is formed at one end of the second cavity 618 (at a terminal end oriented to the outer circumferential surface of the rotor 104) in a circumferential direction of the rotor 104 such that its width It is gradually reduced with a smooth curvature. In other words, the second flow barrier 616 can be configured so that a complete contour oriented towards the outer circumferential surface of the rotor 104 has a smooth curvature while the width is gradually reduced. In the second flow barrier 616, a narrow width portion is formed downstream in the direction of rotation of the rotor 104, and a wide width portion is formed upstream in the direction of rotation of the rotor 104. That is, when the rotor 104 rotates, the narrow width portion in the second flow barrier 616 is followed by the wide width portion.

The third flow barrier 610 and the fourth flow barrier 620 are elongated in a circumferential direction of the rotation shaft 108 at the other ends of the first cavity 608 and the second cavity 618 (at the terminal ends oriented to the central axis of the rotor 104) such that the width of each of the third flow barrier 610 and the fourth flow barrier 620 becomes narrower in proportion to a distance from the axis d and becomes wider in inverse proportion to the distance from axis d.

In the permanent magnet motor contained, in which the permanent magnets are contained in the cavities, the rotational speed of the rotor can be increased to the permissible tension of each rib that depends on a rotor material. When the rotor rotates, a centrifugal force acts on the rotor and can be structurally concentrated in the nerves of the rotor. The magnetic flux can seep through the nerves. Especially, stacking a larger amount of rotor cores to constitute the rotor results in a greater number of nerves, which can cause more magnetic flux to escape through the nerves. Because the leakage of the magnetic flux is precisely the demagnetization of the permanent magnet, the motor according to an embodiment of the present disclosure is configured to perform the demagnetization minimization (i.e., the improvement of the demagnetization resistant force) by the structures of the nerves.

Figure 8 is a view illustrating shapes of the rotor ribs in the engine according to an embodiment of the present disclosure. Especially, the shape of the rib 352 adjacent to the first flow barrier 606 of the rotor 104 is illustrated in Figure 8. As illustrated in Figure 8, the rib 352 is formed between the first flow barrier 606 and an outer circumferential surface. 804 of rotor 104.

The rib 352 adjacent to the first flow barrier 606 is elongated in the direction of rotation (clockwise in Figure 8) of the rotor 104. In addition, the rib 352 is configured so that its width is gradually reduced in the direction of Rotation of the rotor 104. That is, the width of the rib 352 is wider on one side 812 upstream in the direction of rotation of the rotor 104, and is relatively narrower on one side 814 downstream. The width of the nerve 352 is wider on the side 812 upstream 812 to induce the magnetic flux flowing to the permanent magnet 110 inserted in the first cavity 608 to flow to a side where the width of the nerve 352 is wide when the rotor 104 turns. As illustrated in Figure 5 above, when the magnetic flux flowing from the stator 102 to the rotor 104 flows to the permanent magnet 110 inserted in the first

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cavity 608, a corresponding demagnetization force of permanent magnet 110 is produced. Therefore, as the magnetic flux that flows to the permanent magnet 110 decreases, the demagnetization is reduced by the permanent magnet 110. To this end, in the motor according to an embodiment of the present disclosure, the rib 352 is formed to be wider on the side 812 upstream so that the magnetic flux flowing from the stator 102 to the rotor 104 flows into the permanent magnet 110 of the first cavity 608 as little as possible. That is, more magnetic flux flows to the upstream side 812 in which the width of the rib 352 is wide, and the magnetic flux that flows to the permanent magnet 110 of the first cavity 608 is reduced. In this way, the demagnetization force in the permanent magnet 110 is reduced (ie, the demagnetization resistant force increases).

The width of the rib 352 is relatively narrower on the side 814 downstream to sufficiently secure a size of the first flow barrier 606. If the width of the rib 352 widens on the side 814 downstream, it may be insufficient for the size of the first flow barrier 606 to control the flow of the magnetic flow to a desired level, and thus the control effect can be reduced of expected magnetic flux of the first flow barrier 606. Therefore, the width of the nerve 352 can be formed wider on the side 812 upstream so that more magnetic flux can flow through the nerve 352 and that the width of the nerve 352 is formed relatively narrow on the side 814 downstream of so that the size of the first flow barrier 606 is sufficiently secured.

Fig. 9 is a top view of a stator and a rotor of an engine according to an embodiment of the present disclosure. The rotor can rotate in only one direction (clockwise). However, the rotor 904 can rotate in only one direction (counterclockwise). The coils 916 are wound around nine teeth 912 in a stator 902. Between the adjacent teeth 912 a space called slot 914 is defined. Next, a structure will be described in which the coils 916 are wound around the teeth 912 of the stator 902 using the two adjacent teeth 912a and 912b as an example. That is, as illustrated in Figure 9, when the coil 916a is wound around the tooth 912a, the wound coil 916a occupies the left and right spaces (grooves) of the tooth 912a. In addition, when the coil 916b is wound around the tooth 912b, the wound coil 916b occupies the left and right spaces (grooves) of the tooth 912b.

In the rotor 904 are contained six pairs of, that is, twelve, permanent magnets 910 in a radial form so that they are symmetrical with respect to a rotation shaft 908 and so that they are oriented towards an outer circumferential surface of the rotor 904. Due to that the plurality of permanent magnets contained in the radial form in this manner is in the form of radii, the concentrated flow type motor illustrated in Figure 9 is also known as the radius type motor. A pair of permanent magnets 910 constitutes a pole. Therefore, the motor illustrated in Figure 9 is a motor with a 6-pole rotor 904. A portion indicated by the reference number 950 in Figure 9 denotes a portion corresponding to a pole in the stator 902 and in the rotor 904. As can be seen from the portion indicated by the reference number 950, a pair of magnets Permanent 910 has a "V" shape in which they extend from the rotation shaft 908 to an outer circumference of the rotor 904. The number of permanent magnets 910 is not limited to twelve (six pairs), and can be changed to obtain the desired characteristics (for example, the number of poles) of the motor.

In the state in which the plurality of permanent magnets 910 are inserted in the rotor 904, the flow barriers 906 are formed at opposite ends of each permanent magnet 910. In addition, the ribs 952 are formed between the outer circumferential surface of the rotor 904 and the flow barriers 906. The forms of the flow barriers and the nerves in the motor are in close connection with the generation of an electromagnetic excitation force, the formation of a magnetic flux path, an increase / decrease in the demagnetization force and so on. A procedure to minimize demagnetization, that is, to maximize a force resistant to demagnetization, in the permanent magnet includes a procedure to increase the thickness of the permanent magnet or a procedure to increase the distance between the permanent magnet and the stator. The former may be responsible for an increase in the cost of production of the motor because a larger permanent magnet is required, and the latter may be responsible for an increase in the volume of the rotor (or motor) because a wider space is required for the disposition of the permanent magnet. In the motor according to the realization of the present disclosure, a structure of each rotor rib is proposed to minimize the demagnetization of the motor without increasing the size of the permanent magnet or the volume of the motor.

Figure 10 is a view illustrating detailed shapes of the cavities and flow barriers formed in the motor rotor in accordance with an embodiment of the present disclosure. In detail, Figure 10 illustrates a structure of a portion of the rotor 904 which is a circular sector 950 indicated by dashed dashed lines in Figure 9, that is, structures of a pair of permanent magnets constituting a pole and its surroundings. In figure 10, for a detailed description of the cavities and the flow barriers, new reference numbers are given to the cavities and the flow barriers. In Figure 10, the cavities and flow barriers to which the new reference numbers are given include a first cavity 1008, a second cavity 1018, a first flow barrier 1006, a second flow barrier 1016, a third barrier 1010 flow and a fourth flow barrier 1020. Figure 10 (A) illustrates a state in which permanent magnets 910 are not contained in cavities 1008 and 1018, and Figure 10 (B) illustrates a state in which permanent magnets 910 are contained in cavities 1008 and 1018. In Figure 10 (B), the permanent magnets 910 contained are indicated by shading.

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As illustrated in Figure 10 (A), the first flow barrier 1006, the first cavity 1008 and the third flow barrier 1010 are continuously formed on the left side of the axis q from the outer circumferential surface towards the central axis of the rotor 904. In Figure 10 (A), the first flow barrier 1006, the first cavity 1008 and the third flow barrier 1010 are divided by broken lines, which is a virtual division to distinguish them.

The second flow barrier 1016, the second cavity 1018 and the fourth flow barrier 1020 are continuously formed on the right side of the axis q from the outer circumferential surface towards the central axis of the rotor 904. In Figure 10 (A), the second flow barrier 1016, the second cavity 1018 and the fourth flow barrier 1020 are divided by broken lines, which is a virtual division to distinguish them.

In the engine according to an embodiment of the present disclosure, two of the flow barriers formed on the left and right sides of the axis have a structure in which the shapes and positions thereof are asymmetrical. For example, the first flow barrier 1006 and the second flow barrier 1016 illustrated in Figure 10 (A) and Figure 10 (B) have a structure in which the shapes and positions thereof are asymmetrical. This is in consideration of a direction of rotation of the rotor 904. In the engine according to an embodiment of the present disclosure, the asymmetric structure of the first flow barrier 1006 and the second flow barrier 1016 is established in view of the condition that the rotor rotate counterclockwise in the top view as illustrated in Figure 9. This asymmetric structure of the two flow barriers will be described in detail below with reference to Figure 11.

Figure 11 is a view illustrating the asymmetric structure of the pair of flow barriers illustrated in Figure 10. To aid in understanding, the flow barriers and the cavities of the different adjacent poles between each other across the axis d are illustrated. in Figure 11. For example, the first flow barrier 1006, the first cavity 1008 and the third flow barrier 1010 of Figure 11 are elements that constitute a part of a first pole, and the second flow barrier 1016, the Second cavity 1018 and the fourth flow barrier 1020 are elements that constitute a part of a second pole adjacent to the first pole.

In Figure 11, in comparison with the positions of the first and second cavity 1008 and 1018 to contain the permanent magnets 910, the second cavity 1018 is closer to the outer circumferential surface of the rotor 904 than the first cavity 1008. By therefore, there is a position difference indicated by the reference number 1132 along the axis d between the first cavity 1008 and the second cavity 1018. However, the first cavity 1008 has the same length as the second cavity 1018. The Difference in position between the first cavity 1008 and the second cavity 1118 serves to make the positions of the permanent magnets 910 contained (inserted) in the first and second cavity 1008 and 1018 different. Due to the difference in position, it is possible to reduce the demagnetization that occurs in permanent magnets 910.

The first flow barrier 1006 connected to the first cavity 1008 is elongated in a circumferential direction of the rotor 904 at one end of the first cavity 1008 (at a terminal end oriented to the outer circumferential surface of the rotor 904) such that its width is gradually reduced at a soft angle and then at a relatively acute angle. In other words, the first flow barrier 1006 illustrated in Figure 11 may have a cradle shape that is elongated in the circumferential direction of the rotor 904. In this cradle shape, a portion 1112 of a stator-oriented contour 902 is gently inclined, and the other portion 1114 is relatively inclined. In the first flow barrier 1006, the portion 1112 having the gentle inclination is formed downstream in the direction of rotation of the rotor 904, and the other portion 1114 having the steep inclination is formed upstream in the direction of rotation of the rotor 904. That is, when the rotor 904 rotates, the portion 1112 having the smooth inclination at the first flow barrier 1006 is followed by the portion 1114 having the pronounced inclination.

The second flow barrier 1016 connected to the second cavity 1018 is elongated in a circumferential direction of the rotor 904 at one end of the second cavity 1018 (at a terminal end oriented to the outer circumferential surface of the rotor 904) such that its Width is gradually reduced with a smooth curvature. In other words, the second flow barrier 1016 can be configured so that a complete contour oriented to the stator 902 has a smooth curvature while the width is gradually reduced. In the second flow barrier 1016, a narrow width portion is formed downstream in the direction of rotation of the rotor 904, and a wide width portion is formed upstream in the direction of rotation of the rotor 904. That is, when the rotor 904 rotates, the narrow width portion in the second flow barrier 1016 is followed by the wide width portion.

The third flow barrier 1010 and the fourth flow barrier 1020 are elongated in a circumferential direction of the rotation shaft 908 at the other ends of the first cavity 1008 and the second cavity 1018 (at the terminal ends oriented to the central axis of the rotor 904) such that the width of each of the third flow barrier 1010 and the fourth flow barrier 1020 becomes narrower in proportion to a distance from the axis d and becomes wider in inverse proportion to the distance from axis d.

In the permanent magnet motor contained, in which the permanent magnets are contained in the cavities, the rotational speed of the rotor can be increased to the permissible tension of each rib that depends on a rotor material. When the rotor rotates, a centrifugal force acts on the rotor and can

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Structurally focus on the nerves of the rotor. The magnetic flux can seep through the nerves. Especially, stacking a larger amount of rotor cores to constitute the rotor results in a greater number of nerves, which can cause more magnetic flux to escape through the nerves. Because the leakage of the magnetic flux is precisely the demagnetization of the permanent magnet, the motor according to an embodiment of the present disclosure is configured to perform the demagnetization minimization (i.e., the improvement of the demagnetization resistant force) by the structures of the nerves.

Figure 12 is a view illustrating shapes of the rotor ribs in the engine according to an embodiment of the present disclosure. Especially, the shape of the rib 952 adjacent to the first flow barrier 1006 of the rotor 904 is illustrated in Figure 12. As illustrated in Figure 12, the rib 952 is formed between the first flow barrier 1006 and an outer circumferential surface 1204 of rotor 904.

The rib 952 adjacent to the first flow barrier 1006 is formed elongated in the direction of rotation (counterclockwise in Figure 12) of the rotor 904. In addition, the rib 952 is configured so that its width is gradually reduced in the direction of rotation of the rotor 904. That is, the width of the rib 952 is wider on one side 1212 upstream in the direction of rotation of the rotor 904, and is relatively narrower on one side 1214 downstream. The width of the rib 952 is wider on the side 1212 upstream to induce that the magnetic flux flowing to the permanent magnet 910 inserted in the first cavity 1008 flows to a side where the width of the rib 952 is wide when the rotor 904 tour. As illustrated in Figure 5 above, it can be found that the magnetic flux that flows from the stator 902 to the rotor 904 flows to the permanent magnet 910 inserted into the first cavity 1008. The magnetic flux that flows to the permanent magnet inserted into the first cavity 1008 causes a demagnetization force of the permanent magnet 910. Therefore, as the magnetic flux that flows to the permanent magnet 910 decreases, the demagnetization of the permanent magnet 910 can be reduced. To this end, in the motor according to the embodiment of the present disclosure, the rib 952 is formed to be wider on the side 1212 upstream so that the magnetic flux flowing from the stator 902 to the rotor 904 flows into the permanent magnet 910 of the first cavity 1008 as little as possible. That is, more magnetic flux flows to the side 1212 upstream in which the width of the rib 952 is wide, and the magnetic flux that flows to the permanent magnet 910 of the first cavity 1008 is reduced. In this way, the demagnetization force in the permanent magnet 910 is reduced (ie, the demagnetization resistant force increases).

The width of the rib 952 is relatively narrower on the side 1214 downstream to sufficiently secure a size of the first flow barrier 1006. If the width of the rib 952 widens on the side 1214 downstream, it may be insufficient for the size of the first flow barrier 1006 to control the flow of the magnetic flow to a desired level, and thus the control effect can be reduced of expected magnetic flux of the first flow barrier 1006. Therefore, the width of the nerve 952 can be formed wide on the side 1212 upstream so that more magnetic flux can flow through the nerve 952 and that the width of the nerve 952 is formed relatively narrowly on the side 1214 downstream so that that the size of the first flow barrier 1006 is sufficiently secured.

Figure 13 is a top view of a stator and a rotor of an engine according to an arrangement of the present disclosure. The rotor can rotate in only one direction (any one of the clockwise and counterclockwise). However, a rotor 1304 can be rotated in both directions (clockwise and counterclockwise). The coils 1316 are wound around nine teeth 1312 in a stator 1302. Between the adjacent teeth 1312 a space called slot 1314 is defined. Next, a structure will be described in which the coils 1316 are wound around the teeth 1312 of the stator 1302 using the two adjacent teeth 1312a and 1312b as an example. That is, as illustrated in Figure 13, when the coil 1316a is wound around the tooth 1312a, the wound coil 1316a occupies the left and right spaces (grooves) of the tooth 1312a. Also, when the coil 1316b is wound around the tooth 1312b, the wound coil 1316b occupies the left and right spaces of the tooth 1312b.

In the rotor 1304 are contained six pairs of, that is, twelve, permanent magnets 1310 in a radial form so that they are symmetrical with respect to a rotation shaft 1308 and so that they are oriented towards an outer circumferential surface of the rotor 1304. Due to that the plurality of permanent magnets contained in the radial form in this manner is in the form of radii, the concentrated flow type motor illustrated in Figure 13 is known as the radius type motor.

A pair of permanent magnets 1310 constitutes a pole. Therefore, the motor illustrated in Figure 13 is a motor with a 6-pole rotor 1304. A portion indicated by reference number 1350 in Figure 13 denotes a portion corresponding to a pole at stator 1302 and rotor 1304. As can be seen from the portion indicated by reference number 1350, a pair of magnets 1310 permanent has a "V" shape in which they extend from the rotation shaft 1308 to an outer circumference of the rotor 1304. The number of permanent magnets 1310 is not limited to twelve (six pairs), and can be changed to obtain the desired characteristics (for example, the number of poles) of the motor.

In the state in which permanent magnets 1310 of rotor 1304 are inserted, flow barriers 1306 are formed at opposite ends of each permanent magnet 1310. In addition, ribs 1352 and 1354 are formed between the outer circumferential surface of rotor 1304 and flow barriers 1306. The forms of flow barriers and of

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The nerves in the motor are in close connection with the generation of an electromagnetic excitation force, the formation of a magnetic flux path, an increase / decrease in the demagnetization force and so on. A procedure to minimize demagnetization, that is, to maximize a force resistant to demagnetization, in the permanent magnet includes a procedure to increase the thickness of the permanent magnet or a procedure to increase the distance between the permanent magnet and the stator. The former may be responsible for an increase in the cost of production of the motor because a larger permanent magnet is required, and the latter may be responsible for an increase in the volume of the rotor (or motor) because a wider space is required for the disposition of the permanent magnet. In the motor according to the realization of the present disclosure, a structure of each rotor rib is proposed to minimize the demagnetization of the motor without increasing the size of the permanent magnet or the volume of the motor.

Figure 14 is a view illustrating detailed shapes of the cavities and flow barriers formed in the motor rotor in accordance with an arrangement of the present disclosure. In detail, Figure 14 illustrates a structure of a portion of the rotor 1304 which is a circular sector 1350 indicated by dashed dashed lines in Figure 13, that is, structures of a pair of permanent magnets constituting a pole and its surroundings. In figure 14, for a detailed description of the cavities and the flow barriers, new reference numbers are given to the cavities and the flow barriers. In Figure 14, the cavities and flow barriers to which the new reference numbers are given include a first cavity 1408, a second cavity 1418, a first flow barrier 1406, a second flow barrier 1416, a third barrier 1410 flow and a fourth flow barrier 1420.

Figure 14 (A) illustrates a state in which permanent magnets 1310 are not contained in cavities 1408 and 1418, and Figure 14 (B) illustrates a state in which permanent magnets 1310 are contained in cavities 1408 and 1418. In Figure 14 (B), the permanent magnets 1310 contained are indicated by shading.

As illustrated in Figure 14 (A), the first flow barrier 1406, the first cavity 1408 and the third flow barrier 1410 are continuously formed on the left side of the axis q from an outer side to a central portion (i.e. , from the outer circumference towards the central axis) of the rotor 1304. In Figure 14 (A), the first flow barrier 1406, the first cavity 1408 and the third flow barrier 1410 are divided by broken lines, which is a division virtual to distinguish them.

The second flow barrier 1416, the second cavity 1418 and the fourth flow barrier 1420 are continuously formed on the right side of the axis q from the outer side to the central portion (i.e., from the outer circumference to the central axis) of the rotor 1304. In Figure 14 (A), the second flow barrier 1416, the second cavity 1418 and the fourth flow barrier 1420 are divided by broken lines, which is a virtual division to distinguish them.

In the engine according to an embodiment of the present disclosure, two of the flow barriers formed on the left and right sides of the axis have a structure in which the shapes and positions thereof are symmetrical. For example, the first flow barrier 1406 and the second flow barrier 1416 illustrated in Figure 14 (A) and in Figure 14 (B) have a structure in which the shapes and positions thereof are symmetrical. This is in consideration of a rotation direction of the rotor 1304. In the engine according to an embodiment of the present disclosure, the first flow barrier 1406 and the second flow barrier 1416 are configured to have the symmetrical structure in view of The condition that the rotor rotates both clockwise and counterclockwise in the top view as illustrated in Figure 13. This symmetrical structure of the two flow barriers will be described in detail below with reference to Figure 15.

Figure 15 is a view illustrating the symmetrical structure of the pair of flow barriers illustrated in Figure 14. To aid in understanding, the flow barriers and the cavities of the different adjacent poles between each other through the axis d are illustrated. in Figure 15. For example, the first flow barrier 1406, the first cavity 1408 and the third flow barrier 1410 of Figure 14 are elements that constitute a part of a first pole, and the second flow barrier 1416, the Second cavity 1418 and the fourth flow barrier 1420 are elements that constitute a part of a second pole adjacent to the first pole.

In Figure 13, in comparison with the positions of the first and second cavity 1408 and 1418 to contain permanent magnets 1310, the first and second cavity 1408 and 1418 are formed in the same position and length from the center of the rotor 1304. In the engine according to an embodiment of the present disclosure, the first and second cavity 1408 and 1418 are formed in the same position and length from the center of the rotor 1304, which is in consideration of bidirectional rotation (in the sense schedule and counterclockwise) of the engine in accordance with an embodiment of this disclosure.

The first flow barrier 1406 connected to the first cavity 1408 is elongated in a circumferential direction of the rotor 1304 at one end of the first cavity 1008 (at a terminal end oriented to the outer circumferential surface of the rotor 1304) such that its width is gradually reduced at a soft angle and then at a relatively acute angle. In other words, the first flow barrier 1406 illustrated in Figure 15 may have a cradle shape that is elongated in the circumferential direction of the rotor 1304. In this cradle shape, a portion 1512 of a contour oriented to the stator 1302 is inclined

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gently, and the other portion 1514 is relatively inclined. In the first flow barrier 1406, the portion 1512 having the gentle inclination is formed downstream in the direction of rotation (counterclockwise) of the rotor 1304, and the other portion 1514 having the steep inclination is formed upstream in the direction of rotation (counterclockwise) of the rotor 1304. That is, when the rotor 1304 rotates, the portion 1512 having the gentle inclination at the first flow barrier 1406 is followed by the portion 1514 having the pronounced inclination.

The second flow barrier 1416 connected to the second cavity 1418 is formed elongated in a circumferential direction of the rotor 1304 at one end of the second cavity 1418 (at a terminal end oriented to the outer circumferential surface of the rotor 1304) such that its width is gradually reduced at a soft angle and then at a relatively acute angle. In other words, the second flow barrier 1416 illustrated in Figure 15 may have a cradle shape that is elongated in the circumferential direction of rotor 1304. In this cradle shape, a portion 1522 of a stator-oriented contour 1302 is gently inclined, and the other portion 1524 is relatively inclined. In the second flow barrier 1416, the portion 1522 having the gentle inclination is formed downstream in the direction of rotation (clockwise) of the rotor 1304, and the other portion 1524 having the steep inclination is formed upstream in the direction of rotation (clockwise) of the rotor 1304. That is, when the rotor 1304 rotates, the portion 1522 having the smooth inclination in the second flow barrier 1416 is followed by the portion 1524 having the pronounced inclination.

The third flow barrier 1410 and the fourth flow barrier 1420 are elongated in a circumferential direction of the rotation shaft 1308 at the other ends of the first cavity 1408 and the second cavity 1418 (at the terminal ends oriented to the central axis of the rotor 1304) such that the width of each of the third flow barrier 1410 and the fourth flow barrier 1420 becomes narrower in proportion to a distance from the axis d and becomes wider in inverse proportion to the distance from axis d.

In the permanent magnet motor contained in which the permanent magnets are contained in the cavities, the rotational speed of the rotor can be increased to the permissible tension of each rib that depends on a rotor material. When the rotor rotates, a centrifugal force acts on the rotor and can be structurally concentrated in the nerves of the rotor. The magnetic flux can seep through the nerves. Especially, stacking a larger amount of rotor cores to constitute the rotor results in a greater number of nerves, which can cause more magnetic flux to escape through the nerves. Because the leakage of the magnetic flux is precisely the demagnetization of the permanent magnet, the motor according to an embodiment of the present disclosure is configured to perform the demagnetization minimization (i.e., the improvement of the demagnetization resistant force) by the structures of the nerves.

Figure 16 is a view illustrating shapes of the rotor ribs in the motor according to an arrangement of the present disclosure. Especially, the shapes of the first and second rib 1352 and 1354 adjacent to the first and second flow barrier 1406 and 1416 of the rotor 1304 are illustrated in Figure 16. As illustrated in Figure 16, the first rib 1352 is formed between the first flow barrier 1406 and an outer circumferential surface 1604 of the rotor 1304, and the second rib 1354 is formed between the second flow barrier 1416 and the outer circumferential surface 1604 of the rotor 1304. The first rib 1352 and the second rib 1354 they are symmetrical with respect to the d axis. The shape of the first rib 1352 is in consideration of when the rotor 1304 rotates counterclockwise, and the shape of the second rib 1354 is in consideration of when the rotor 1304 rotates clockwise.

The first rib 1352 adjacent to the first flow barrier 1406 is elongated in the direction of rotation (clockwise or counterclockwise) of the rotor 1304. In addition, the first rib 1352 is configured so that its width is gradually reduced in the direction of rotation of the rotor 1304. That is, the width of the first rib 1352 is wider on one side 1612 upstream in the direction of rotation of the rotor 1304, and is relatively narrower on one side 1614 downstream. The width of the first nerve 1352 is wider on the side 1612 upstream to induce the magnetic flux flowing to the permanent magnet 1310 inserted in the first cavity 1408 to flow to a side where the width of the first nerve 1352 is wide when the rotor 1304 rotates. As illustrated in Figure 5 above, it can be found that the magnetic flux that flows from the stator 1302 to the rotor 1304 flows to the permanent magnet 1310 inserted in the first cavity 1408. The magnetic flux that flows to the permanent magnet inserted in the first cavity 1408 causes a demagnetization force of the permanent magnet 1310. Therefore, as the magnetic flux that flows to the permanent magnet 1310 decreases, the demagnetization of the permanent magnet 1310 can be reduced. To this end, in the engine according to the embodiment of the present disclosure, the first rib 1352 is formed to be wider on the side 1612 upstream so that the magnetic flux flowing from the stator 1302 to the rotor 1304 flows to the permanent magnet 1310 of the first cavity 1408 as little as possible. That is, more magnetic flux flows to the upstream side 1612 in which the width of the first rib 1352 is wide, and the magnetic flux that flows to the permanent magnet 1310 of the first cavity 1408 is reduced. In this way, the demagnetization force in the permanent magnet 1310 is reduced (ie, the demagnetization resistant force increases).

The width of the first rib 1352 is relatively narrower on the side 1614 downstream to sufficiently secure a size of the first flow barrier 1406. If the width of the first rib 1352 widens on the side 1614 downstream, it may be insufficient for the size of the first flow barrier 1406 to control the flow of the magnetic flux to a desired level, and thus the effect of expected magnetic flux control of the first flow barrier 1406. Therefore, the width of the first rib 1352 can

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be formed wide on the side 1612 upstream so that more magnetic flux can flow through the first rib 1352 and that the width of the first rib 1352 is formed relatively narrow on the side 1614 downstream so that the size of the first barrier 1406 of flow is sufficiently assured.

The second rib 1354 adjacent to the second flow barrier 1416 is elongated in the direction of rotation (clockwise or counterclockwise) of the rotor 1304. In addition, the second rib 1354 is configured so that its width is gradually reduced in the direction of rotation of the rotor 1304. That is, the width of the second rib 1354 is wider on one side 1622 upstream in the direction of rotation of the rotor 1304, and is relatively narrower on one side 1624 downstream. The width of the second rib 1354 is wider on the side 1622 upstream to induce the magnetic flux flowing to the permanent magnet 1310 inserted in the second cavity 1418 to flow to a side where the width of the second rib 1354 is wide when the rotor 1304 rotates. As illustrated in Figure 5 above, it can be found that the magnetic flux that flows from the stator 1302 to the rotor 1304 flows to the permanent magnet 1310 inserted in the second cavity 1418. The magnetic flux that flows to the permanent magnet inserted in the second cavity 1418 causes a demagnetization force of the permanent magnet 1310. Therefore, as the magnetic flux that flows to the permanent magnet 1310 decreases, the demagnetization of the permanent magnet 1310 can be reduced. To this end, in the engine according to the embodiment of the present disclosure, the second rib 1354 is formed to be wider on the side 1622 upstream so that the magnetic flux flowing from the stator 1302 to the rotor 1304 flows to the permanent magnet 1310 of the second cavity 1418 as little as possible. That is, more magnetic flux flows to the upstream side 1622 in which the width of the second rib 1354 is wide, and the magnetic flux that flows to the permanent magnet 1310 of the second cavity 1418 is reduced. In this way, the demagnetization force in the permanent magnet 1310 is reduced (ie, the demagnetization resistant force increases).

The width of the second rib 1354 is relatively narrower on the side 1624 downstream to sufficiently secure a size of the second flow barrier 1416. If the width of the second rib 1354 widens on the side 1624 downstream, it may be insufficient for the size of the second flow barrier 1416 to control the flow of the magnetic flux to a desired level, and thus the effect of expected magnetic flux control of the second flow barrier 1416. Therefore, the width of the second rib 1354 can be formed wide on the side 1622 upstream so that more magnetic flux can flow through the second rib 1354 and so that the width of the second rib 1354 is formed relatively narrow on the current side 1624 below so that the size of the second flow barrier 1416 is sufficiently secured.

Figure 17 is a top view of a stator and a rotor of an engine according to an arrangement of the present disclosure. An arrangement of the present disclosure illustrates a motor in which a single permanent magnet 1710 serves as a pole, a rotor 1704 and a rotation shaft 1708 rotate in one direction (for example, clockwise). The coils 1716 are wound around nine teeth 1712 in a stator 1702. Between the adjacent teeth 1712 a space called groove 1714 is defined. Next, a structure will be described in which the coils 1716 are wound around the teeth 1712 of the stator 1702 using the two adjacent teeth 1712a and 1712b as an example. That is, as illustrated in Figure 17, when the coil 1716a is wound around the tooth 1712a, the wound coil 1716a occupies the left and right spaces (grooves) of the tooth 1712a. Also, when the coil 1716b is wound around the tooth 1712b, the wound coil 1716b occupies the left and right spaces of the tooth 1712b.

In the rotor 1704 six permanent magnets 1710 are contained in a radial form so that they are symmetrical with respect to the rotation shaft 1708 and so that they are oriented towards an outer circumferential surface of the rotor 1704. Because the plurality of permanent magnets contained in the Radial shape in this way is in the form of spokes, the concentrated flow type engine illustrated in Figure 17 is called the spoke type engine.

A permanent 1710 magnet serves as a pole. Therefore, the motor illustrated in Figure 17 is a motor with a 6-pole rotor 1704. Each permanent magnet 1710 has a linear "I" shape that is elongated from the rotation shaft 1708 to the outer circumferential surface of the rotor 1704. The number of permanent magnets 1710 is not limited to six, and can be changed to obtain the desired characteristics. (for example, the number of poles) of the motor. The magnetization directions of the permanent magnets of Figure 17 will be described in detail below. The plurality of permanent magnets 1710 are arranged to face each other through an axis d. Permanent magnets 1710 facing each other across the d axis are magnetized at equal polarities between sf (N and N poles or S and S poles). When magnetized along an q axis, each permanent magnet 1710 is magnetized at different polarities between sf (N and S poles or S and N poles).

In the state in which each permanent magnet 1710 is inserted, the flow barriers 1706 are formed at opposite ends of the permanent magnet 1710. In addition, a rib 1752 is formed between one of the flow barriers 1706 of the rotor 1704 and an inner surface of the stator 1702. The shapes of the flow barriers and the nerve in the motor are in close connection with the generation of a force of electromagnetic excitation, the formation of a magnetic flux path, an increase / decrease in the demagnetization force, and so on. A procedure to minimize demagnetization, that is, to maximize a force resistant to demagnetization, in the permanent magnet includes a procedure to increase the thickness of the permanent magnet or a procedure to increase the distance between the permanent magnet and the stator. The former may be responsible for an increase in the cost of production of the engine because a permanent magnet is required more

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large, and the latter may be responsible for an increase in the volume of the rotor (or motor) because a wider space is required for permanent magnet arrangement. In the motor according to the realization of the present disclosure, a structure of each rotor rib is proposed to minimize the demagnetization of the motor without increasing the size of the permanent magnet or the volume of the motor.

Figure 18 is a view illustrating a shape of the rotor nerve in the motor according to an arrangement of the present disclosure. As illustrated in Figure 18, the rib 1752 is formed between the flow barrier 1706 and an outer circumferential surface 1804 of the rotor 1704. The rib 1752 adjacent to the flow barrier 1706 is formed elongated in a direction of rotation (in the direction of schedule in Figure 18) of the rotor 1704. In addition, the rib 1752 has a shape in which its width is gradually reduced in the direction of rotation of the rotor 1704. That is, the width of the rib 1752 is wider on one side 1812 upstream in the direction of rotation of rotor 1704, and is relatively narrower on one side 1814 downstream.

The width of the nerve 1752 is wider on the side 1812 upstream to induce the magnetic flux flowing to the permanent magnet 1710 inserted in a cavity 1808 to flow to one side where the width of the nerve 1752 is wide. As illustrated in Figure 5 above, it can be found that the magnetic flux that flows from the stator 1702 to the rotor 1704 flows to the permanent magnet 1710 inserted in the cavity 1808. The magnetic flux that flows to the permanent magnet inserted in the cavity 1808 causes a demagnetization force of the permanent 1710 magnet. Therefore, as the magnetic flux that flows to the permanent magnet 1710 decreases, the demagnetization of the permanent magnet 1710 can be reduced. To this end, in the engine according to the embodiment of the present disclosure, the rib 1752 is formed to be wider on the side 1812 upstream so that the magnetic flux flowing from the stator 1702 to the rotor 1704 flows to the 1710 permanent cavity 1808 magnet as little as possible. That is, more magnetic flux flows to the side 1812 upstream in which the width of the rib 1752 is wide, and the magnetic flux that flows to the permanent magnet 1710 of the cavity 1808 is reduced. In this way, the demagnetization force in the permanent magnet 1710 is reduced (ie, the demagnetization resistant force increases).

The width of the rib 1752 is relatively narrower on the side 1814 downstream to ensure a sufficiently large size of the flow barrier 1706 to control a flow of the magnetic flow to a desired level. If the width of the rib 1752 widens on the side 1814 downstream, the size of the flow barrier 1706 may be insufficient, and thus the expected magnetic flux control effect of the flow barrier 1706 can be reduced. Therefore, the width of the nerve 1752 can be formed wide on the side 1812 upstream so that more magnetic flux can flow through the nerve 1752 and that the width of the nerve 1752 is formed relatively narrowly on the side 1814 downstream so that that the size of the flow barrier 1706 is sufficiently secured.

Figure 19 is a top view of a stator and a rotor of an engine according to an arrangement of the present disclosure. An arrangement of the present disclosure illustrates a motor in which a single permanent magnet 1910 serves as a pole, a rotor 1904 and a rotation shaft 1908 rotate in one direction (for example, counterclockwise). The coils 1916 are wound around nine teeth 1912 in a stator 1902. Between the adjacent teeth 1912 a space called groove 1914 is defined. Next, a structure will be described in which the coils 1916 are wound around the teeth 1912 of the stator 1902 using the two adjacent teeth 1912a and 1912b as an example. That is, as illustrated in Figure 19, when the coil 1916a is wound around the tooth 1912a, the wound coil 1916a occupies the left and right spaces (grooves) of the tooth 1912a. Also, when the coil 1916b is wound around the tooth 1912b, the coil 1916b wound occupies the left and right spaces of the tooth 1912b.

In a core 1928 of magnetic flux concentration of the rotor 1904 six permanent magnets 1910 are contained in a radial form so that they are symmetrical with respect to the rotation shaft 1908 and so that they are oriented towards an outer circumferential surface of the rotor 1904. Because the plurality of permanent magnets contained in the radial form in this way is in the form of radii, the concentrated flow type motor illustrated in Figure 19 is known as the radius type motor.

A permanent 1910 magnet serves as a pole. Therefore, the motor illustrated in Figure 19 is a motor with a 1904 6-pole rotor. Each permanent magnet 1910 has a linear "I" shape that is elongated from the rotation shaft 1908 to the outer circumferential surface of the rotor 1904. The number of permanent magnets 1910 is not limited to six, and can be changed to obtain the desired characteristics. (for example, the number of poles) of the motor. The magnetization directions of the permanent magnets of Figure 19 will be described in detail below. The plurality of permanent magnets 1910 are arranged to face each other through an axis d. Permanent magnets 1910 facing each other across the d axis are magnetized at equal polarities between sf (N and N poles or S and S poles). When magnetized along a q axis, each permanent 1910 magnet is magnetized at different polarities between sf (N and S poles or S and N poles).

In the state in which each permanent magnet 1910 is inserted, the flow barriers 1906 are formed at opposite ends of the permanent magnet 1910. In addition, a 1952 rib is formed between one of the flow barriers 1906 of the rotor 1904 and an inner surface of the stator 1902.

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The shapes of the flow and nerve barriers in the motor are in close connection with the generation of an electromagnetic excitation force, the formation of a magnetic flux path, an increase / decrease in the demagnetization force, and so on. A procedure to minimize demagnetization, that is, to maximize a force resistant to demagnetization, in the permanent magnet includes a procedure to increase the thickness of the permanent magnet or a procedure to increase the distance between the permanent magnet and the stator. The former may be responsible for an increase in the cost of production of the motor because a larger permanent magnet is required, and the latter may be responsible for an increase in the volume of the rotor (or motor) because a wider space is required for the disposition of the permanent magnet. In the motor according to the realization of the present disclosure, a structure of each rotor rib is proposed to minimize the demagnetization of the motor without increasing the size of the permanent magnet or the volume of the motor.

Figure 20 is a view illustrating a shape of the rotor rib in the motor according to an arrangement of the present disclosure. As illustrated in Figure 20, the rib 1952 is formed between the flow barrier 1906 and an outer circumferential surface 2004 of the rotor 1904. The rib 1952 adjacent to the flow barrier 1906 is elongated in a direction of rotation (in the direction counterclockwise in Figure 20) of the 1904 rotor. In addition, the 1952 rib has a shape in which its width is gradually reduced in the direction of rotation of the 1904 rotor. That is, the 1952 rib width is wider on a 2012 side. upstream in the direction of rotation of rotor 1904, and is relatively narrower on one side 2014 downstream.

The reason why the width of the 1952 nerve is wider on the 2012 side upstream is to induce that the magnetic flux that flows to the permanent 1910 magnet inserted in a 2008 cavity flows to a side where the 1952 nerve width is wide . As illustrated in Figure 5 above, it can be found that the magnetic flux that flows from the stator 1902 to the rotor 1904 flows to the permanent magnet 1910 inserted in the cavity 2008. The magnetic flux that flows to the permanent magnet inserted in the cavity 2008 causes a demagnetization force of the permanent 1910 magnet. Therefore, as the magnetic flux that flows to the permanent magnet 1910 decreases, the demagnetization of the permanent magnet 1910 can be reduced. To this end, in the engine according to the embodiment of the present disclosure, the rib 1952 is formed to be wider on the 2012 side upstream so that the magnetic flux flowing from the stator 1902 to the rotor 1904 flows to the Magnet 1910 permanent cavity 2008 as little as possible. That is, more magnetic flux flows to the 2012 side upstream in which the width of the 1952 rib is wide, and the magnetic flux that flows into the permanent 1910 magnet of the 2008 cavity is reduced. In this way, the demagnetization force in the permanent magnet 1910 is reduced (ie, the demagnetization resistant force increases).

The width of the rib 1952 is relatively narrower on the side 2014 downstream to ensure a large enough size of the flow barrier 1906 to control a flow of the magnetic flow to a desired level. If the width of the rib 1952 widens on the side 2014 downstream, the size of the flow barrier 1906 may be insufficient, and thus the expected magnetic flux control effect of the flow barrier 1906 can be reduced. Therefore, the width of the nerve 1952 can be formed wide on the 2012 side upstream so that more magnetic flux can flow through the 1952 nerve and that the width of the 1952 nerve is formed relatively narrow on the 2014 side downstream so that that the size of the flow barrier 1906 is sufficiently secured.

Figure 21 is a top view of a stator and a rotor of an engine according to an arrangement of the present disclosure. An arrangement of the present disclosure illustrates a motor in which a single permanent magnet 2110 serves as a pole, a rotor 2104 and a rotation shaft 2108 rotate in both directions (for example, clockwise and counterclockwise). The coils 2116 are wound around nine teeth 2112 in a stator 2102. Between the adjacent teeth 2112 a space called groove 2114 is defined. Next, a structure will be described in which the coils 2116 are wound around the teeth 2112 of the stator 2102 using the two adjacent teeth 2112a and 2112b as an example. That is, as illustrated in Figure 21, when the coil 2116a is wound around the tooth 2112a, the wound coil 2116a occupies the left and right spaces (grooves) of the tooth 2112a. Also, when the coil 2116b is wound around the tooth 2112b, the wound coil 2116b occupies the left and right spaces of the tooth 2112b.

In a core 2128 of magnetic flux concentration of the rotor 2104 six permanent magnets 2110 are contained in a radial form so that they are symmetrical with respect to the rotation shaft 2108 and so that they are oriented towards an outer circumferential surface of the rotor 2104. Because the plurality of permanent magnets contained in the radial form in this way is in the form of radii, the concentrated flow type motor illustrated in Figure 21 is known as the radius type motor.

A permanent 2110 magnet serves as a pole. Therefore, the motor illustrated in Figure 21 is a motor with a 6-pole rotor 2104. Each permanent magnet 2110 has a linear "I" shape that is elongated from the rotation shaft 2108 to the outer circumferential surface of the rotor 2104. The number of permanent magnets 2110 is not limited to six, and can be changed to obtain the desired characteristics. (for example, the number of poles) of the motor. The magnetization directions of the permanent magnets of Figure 21 will be described in detail below. The plurality of permanent magnets 2110 are arranged to face each other through an axis d. Permanent magnets 2110 facing each other across the d axis are magnetized at equal polarities between sf (N and N poles or S and S poles). When magnetized along an q axis, each magnet

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Permanent 2110 is magnetized at different polarities between sf (N and S poles or S and N poles).

In the state in which each permanent magnet 2110 is inserted, the flow barriers 2106 are formed at opposite ends of the permanent magnet 2110. In addition, the ribs 2152 and 2154 are formed between one of the flow barriers 2106 of the rotor 2104 and an inner surface of the stator 2102.

The shapes of the flow barriers and the nerves in the motor are in close connection with the generation of an electromagnetic excitation force, the formation of a magnetic flux path, an increase / decrease in the demagnetization force, and so on. A procedure to minimize demagnetization, that is, to maximize a force resistant to demagnetization, in the permanent magnet includes a procedure to increase the thickness of the permanent magnet or a procedure to increase the distance between the permanent magnet and the stator. The former may be responsible for an increase in the cost of production of the motor because a larger permanent magnet is required, and the latter may be responsible for an increase in the volume of the rotor (or motor) because a wider space is required for the disposition of the permanent magnet. In the motor according to the realization of the present disclosure, a structure of each rotor rib is proposed to minimize the demagnetization of the motor without increasing the size of the permanent magnet or the volume of the motor.

Figure 22 is a view illustrating shapes of the rotor ribs in the motor according to an arrangement of the present disclosure. As illustrated in Figure 22, the ribs 2152 and 2154 are formed between the flow barrier 2106 and an outer circumferential surface 2204 of the rotor 2104. The ribs 2152 and 2154 are formed in a body, but two reference numbers are provided for The convenience of the description. This is because the ribs 2152 and 2154 of the motor according to an embodiment of the present disclosure have shapes that take into account the two-way rotation of the rotor 2104. This will be described in detail below. The ribs 2152 and 2154 adjacent to the flow barrier 2106 are formed elongated in the directions of rotation (clockwise and counterclockwise in Figure 22) of the rotor 2104. In addition, each of the ribs 2152 and 2154 has a shape in the that its width is gradually reduced in the direction of rotation of rotor 2104. That is, the width of rib 2152 considering rotation counterclockwise of rotor 2104 is wider on one side 2212a upstream in the direction of rotation (counterclockwise) of rotor 2104, and is relatively narrower on one side 2214 downstream. In addition, the width of the rib 2154 considering the rotation clockwise of the rotor 2104 is wider on one side 2212b upstream in the direction of rotation (counterclockwise) of the rotor 2104, and is relatively narrower on one side 2214 downstream.

The width of the rib 2152 is wider on the side 2212a upstream to induce the magnetic flux flowing to the permanent magnet 2110 inserted in a cavity 2208 to flow to a side where the width of the rib 2152 is wide. As illustrated in Figure 5 above, it can be found that the magnetic flux that flows from the stator 2102 to the rotor 2104 flows to the permanent magnet 2110 inserted in the cavity 2208. The magnetic flux that flows to the permanent magnet inserted in the cavity 2208 causes a demagnetization force of the permanent 2110 magnet. Therefore, as the magnetic flux that flows to the permanent magnet 2110 decreases, the demagnetization of the permanent magnet 2110 can be reduced. To this end, in the motor according to the embodiment of the present disclosure, the rib 2152 is formed to be wider on the side 2212a upstream so that the magnetic flux flowing from the stator 2102 to the rotor 2104 flows to the 2110 permanent magnet of cavity 2208 as little as possible. That is, more magnetic flux flows to the upstream side 2212a in which the width of the rib 2152 is wide when the rotor 2104 rotates clockwise, and the magnetic flux flowing to the permanent magnet 2110 of the cavity 2208 is reduced. In this way, the demagnetization force in the permanent magnet 2110 is reduced (ie, the demagnetization resistant force increases). Similar to nerve 2152, in the case of nerve 2154, more magnetic flux flows to the side 2212b upstream in which the width of nerve 2154 is wide when rotor 2104 rotates counterclockwise, and the magnetic flux flowing to the permanent magnet 2110 of the cavity 2208 is reduced. In this way, the demagnetization force in the permanent magnet 2110 is reduced (ie, the demagnetization resistant force increases).

The width of each of the ribs 2152 and 2154 is relatively narrower on the side 2214 downstream to ensure a sufficient size of the flow barrier 2106 to control a flow of the magnetic flow to a desired level. If the width of each of the ribs 2152 and 2154 widens on the side 2214 downstream, the size of the flow barrier 2106 may be insufficient, and in this way the expected magnetic flux control effect of the barrier can be reduced 2106 flow. Therefore, the width of each of the ribs 2152 and 2154 can be formed wide on each side 2212a and 2212b upstream so that more magnetic flux can flow through each of the ribs 2152 and 2154 and that the width of each of the ribs 2152 and 2154 is formed relatively narrow on the common side 2214 downstream so that the size of the flow barrier 2106 is sufficiently secured.

Figure 23 is a view illustrating the result of the demagnetization analysis when the shapes of the nerves of a unidirectional rotary motor are symmetrical. The shapes of the unidirectional rotary motor nerves according to the embodiment of the present disclosure have the asymmetric structure illustrated in Figure 7 or 11 The unidirectional rotary motor nerves acting as a comparative model illustrated in Figure 23 are symmetrical , and its forms are different from those of the realization of the present disclosure. As a reference, for the demagnetization analysis of Figure 23 an electric current of 50 A (peak) was applied at a temperature of -20 ° C.

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Figure 23 (A) illustrates a magnetic force of a permanent magnet 2310 before the demagnetization analysis of the unidirectional rotary motor in which the ribs have the symmetrical structure, and Figure 23 (B) illustrates the magnetic force of the permanent magnet 2310 after of the demagnetization analysis of the unidirectional rotary motor in which the nerves have the symmetrical structure. In Figures 23 (A) and 23 (B), a level of demagnetization can be recognized after the demagnetization analysis by comparing corner portions 2360 of the permanent magnet 2310 that are oriented to a stator2302.

Figure 23 (C) is a graph for comparing electromotive forces (EMF) before and after the demagnetization analysis of the unidirectional rotary motor in which the nerves have the symmetrical structure. A difference between the EMFs before and after the demagnetization analysis can be found more clearly from the graph illustrated in Figure 23 (C). That is, the EMF before the demagnetization analysis is 33.71075963 V and the EMF after the demagnetization analysis is 32.46415948 V, so it can be seen that the difference is approximately 1.24660015 V. Calculating this in percentage terms , the difference is approximately 3.70%. Consequently, it can be found that a demagnetization rate in the nerve structure as illustrated in Figure 23 is approximately 3.70%.

Figure 24 is a view illustrating the result of the demagnetization analysis when the unidirectional rotary motor nerves (rotary motor counterclockwise) according to an embodiment of the present disclosure are asymmetric. As a reference, for the demagnetization analysis of Figure 24 an electric current of 50 A (peak) was applied at a temperature of -20 ° C.

Figure 24 (A) illustrates a magnetic force of a permanent magnet 2410 before the demagnetization analysis of the unidirectional rotary motor in which the ribs have the symmetrical structure, and Figure 24 (B) illustrates the magnetic force of the permanent magnet 2410 after of the demagnetization analysis of the unidirectional rotary motor in which the nerves have the symmetrical structure. In Figures 24 (A) and 24 (B), a level of demagnetization can be recognized after the demagnetization analysis by comparing corner portions 2460 of the permanent magnet 2410 that are oriented to a stator 2402.

Figure 24 (C) is a graph to compare electromotive forces (EMF) before and after the demagnetization analysis of the unidirectional rotary motor in which the nerves have the symmetrical structure. A difference between the EMFs before and after the demagnetization analysis can be found more clearly from the graph illustrated in Figure 24 (C). That is, the EMF before the demagnetization analysis is 33.55994991 V and the EMF after the demagnetization analysis is 32.57764857 V, so it can be seen that the difference is approximately 0.98230134 V. Calculating this in percentage terms , the difference is approximately

2.93% Accordingly, it can be found that the demagnetization rate in the flow barrier structure according to an embodiment of the present disclosure is approximately 2.93%.

Thus, comparing the result of the demagnetization analysis of the unidirectional rotary motor according to an embodiment of the present disclosure with the result of the demagnetization analysis of the comparative model of Figure 23, the result of the demagnetization analysis of the comparative model of the Figure 23 shows that the demagnetization speed is approximately 3.70%, while the result of the demagnetization analysis of the unidirectional rotary motor, illustrated in Figure 24, in accordance with an embodiment of the present disclosure shows that the speed demagnetization is approximately

2.93% Therefore, it can be found that the speed of demagnetization in the asymmetric nerve structure of the unidirectional rotary motor according to an embodiment of the present disclosure is relatively low.

Accordingly, it can be found that the objective of the present disclosure, that is, to reduce the demagnetization speed (or increase the demagnetization resistant force) of the motor, is reliably achieved through the nerve structure as in the embodiment of the present disclosure. Furthermore, even in the case of the unidirectional rotary motor (rotary motor clockwise) according to an embodiment of the present disclosure, it is possible to obtain a demagnetization speed reduction effect at a level similar to the previous one.

Figure 25 is a view illustrating the results of the analysis of the counter-electromotive forces without load and the harmonics of the bi-directional rotary motor according to an embodiment of the present disclosure and the comparative model. Figure 25 (A) illustrates the results of the analysis of the counter-electromotive forces without load of the bi-directional rotary motor according to an embodiment of the present disclosure and the comparative model, and Figure 25 (B) illustrates the results of the harmonic analysis of the Two-way rotary motor according to an embodiment of the present disclosure and the comparative model. From the results of the analysis of the counter-electromotive forces without load and the harmonics in Figures 25 (A) and 25 (B), it can be found that the demagnetization speed of the two-way rotary motor according to an embodiment of the present disclosure It is relatively low.

Figure 26 illustrates load lines at the ends of the permanent magnets of the bi-directional rotary motor according to an embodiment of the present disclosure and the comparative model. As illustrated in Figure 26, in comparison with the demagnetization forces at the ends of the permanent magnets, it can be found that the demagnetization force of the bidirectional rotary motor according to an embodiment of the present

disclosure is relatively less than that of the comparative model. As a reference, for the analysis of Figure 26 an electric current of 30 A (peak) was applied.

In accordance with the embodiments of the present disclosure, the demagnetization of the permanent magnet motor is minimized and the demagnetization resistant force is improved without increasing the thickness of each permanent magnet 5 nor the distance between each permanent magnet and the stator. Thus, because the thickness of each permanent magnet and the distance between each permanent magnet and the stator do not increase, the cost of production of the motor does not increase and the volume of the motor does not increase. However, the demagnetization resistant motor force can be improved.

Claims (8)

5 10 fifteen twenty 25 30 35 40 1. A rotor to rotate in one direction in an engine, the rotor comprising: a first and second cavities (608, 618) to contain a permanent first and second magnets (110a, 110b, 110d, 110e) a first and a second flow barrier (606, 616) to communicate with the respective ends of the first and second cavities closest to an outer circumferential surface of the rotor (104, 904); and respective ribs (352, 952) formed between the outer circumferential surface of the rotor (104, 904) and the first and second flow barriers (606, 616) in which a first end of each of the ribs (352, 952) on an upstream side in a direction of rotation of the rotor (104,904) is wider than a second end of the rib (352,952) on a side downstream in the direction of rotation of the rotor (104,904), characterized in that the first and the second cavities (608, 618) are arranged in parallel, in which one of the first and second cavities (608, 618) is arranged to be closer to the outer circumferential surface of the rotor (104, 904) than the another of the first and second cavities (608,618). 2. The rotor according to claim 1, wherein the ribs (352, 952) are elongated in a circumferential direction of the rotor (104, 904). 3. The rotor according to claim 2, wherein a width of the first end of each of the ribs (352, 952) is sharply reduced in the direction of rotation of the rotor (104, 904), and a width of the The second end of each of the ribs (352 952) is gently reduced in the direction of rotation of the rotor (104, 904). 4. The rotor according to claim 1, wherein each of the first flow barrier (606) is configured such that a width of one end of the flow barrier (608) on an upstream side in a Rotation direction of the rotor (104,904) is narrower than a width of the other end of the flow barrier on a downstream side in the direction of rotation of the rotor (104, 904). 5. The rotor according to claim 1, wherein the first cavity (608), the first flow barrier (606) and the respective rib (352) are continuously formed in a direction towards the outer circumferential surface of the rotor ( 104, 904). 6. The rotor according to claim 1, wherein the first cavity (608) of a pair of first and second cavities (608, 618) and the next second cavity (618) closest to the next first and second pair of cavities (608, 618) closest in the circumferential direction of the rotor together they constitute a pole, and in which said first and second cavities (608, 618) of two closed pairs are arranged radially around a shaft (108, 908) of rotation of the rotor (104, 904) towards the outer circumferential surface of the rotor (104, 904). 7. The rotor according to claim 6, wherein said first and second cavities (608, 618) of two closed pairs together form a "V" shape in which the first and second cavities (608, 618) they extend from the shaft (108, 908) of rotation of the rotor (104, 904) to the outer circumferential surface of the rotor (104, 904). 8. An engine comprising: a stator (102, 902, 1302, 1702, 1902, 2102, 2302, 2402) in which the coils (116, 916, 1316, 1716, 1916) are wound; Y a rotor according to any one of the preceding claims, rotatably installed inside the stator.