Magnet, motor including same, and washing machine including motor

Abstract

A magnet, a motor including the magnet, and a washing machine including the motor are provided. A magnet according to one aspect of the present invention includes: at least one pole region formed in an arc shape and arranged side by side in a circumferential direction, the at least one pole region having a respective magnetic focus center different from a center of an inner diameter of the at least one pole region, the at least one pole region satisfying the following mathematical expression: a magnetic field of the at least one pole region satisfies a magnetic field of the at least one pole region, and a magnetic field of the at least one pole region satisfies a magnetic field of the at least one pole region; # imgabs0 # satisfies Xlt under the condition that at least one polar region is one; 7.5, in the case that at least one of the polar regions is two, Xlt is satisfied; 6, under the condition that the number of at least one polar region is three, Xlt is met; 4.5, when the number of at least one polar region is four, Xlt is satisfied; and 3.5.

Description

Technical Field

[0001] The present invention relates to a magnet, a motor including the magnet, and a washing machine including the motor. More specifically, the present invention relates to a magnet for improving back electromotive force, a motor including the magnet, and a washing machine including the motor. Background Art

[0002] Generally, a washing machine includes an outer tub for containing washing water and an inner tub rotatably disposed in the outer tub and containing laundry such as clothes. As the inner tub rotates, the laundry is washed and dehydrated.

[0003] Washing machines can be divided into: top loading type, in which the rotation center of the inner tank is formed in a direction perpendicular to the floor, so that laundry can be put in from the top; and front loading type, in which the rotation center of the inner tank is formed in a direction horizontal to the floor or inclined in a direction descending as it approaches the rear end, so that laundry can be put in from the front.

[0004] Top-mounted washing machines can be roughly divided into agitator type and pulsator type. The agitator type washes by rotating a washing rod erected in the center of the inner tank, while the pulsator type washes by rotating a disc-shaped pulsator formed at the bottom of the inner tank.

[0005] A front-loading washing machine is generally referred to as a "drum washing machine". A lifter is provided on the inner circumference of an inner tub. As the drum rotates, the lifter lifts and drops the laundry to perform washing.

[0006] The washing machine is driven in two main operation modes (washing mode, dehydration mode) having operation conditions different from each other.

[0007] In order to satisfy the two main operation modes at the same time, the washing machine has a clutch to operate the output shaft with a gear ratio of n:1 at low speed and high torque (washing mode), or with a gear ratio of 1:1 at high speed and low torque (spinning mode).

[0008] In this case, there is a structure in which the power consumption is reduced and the operation efficiency of the motor is improved by adding a planetary gear.

[0009] Generally, an outer rotor motor is installed in a washing machine. An outer rotor motor has a stator wound with coils disposed inside, and a rotor is arranged radially outside the stator like a magnet surrounding the coils of the stator. The rotor includes a plurality of magnets arranged radially.

[0010] Before becoming a magnet, the electrons in a general magnetic body are randomly arranged. In order to magnetize such a magnetic body, the electron arrangement in the magnetic body is first oriented in a predetermined direction, and then the magnetization process is carried out by applying an external magnetic field to polarize the magnetic body, thereby forming a permanent magnet.

[0011] Under the same magnet usage standard, in order to increase the magnitude of the back electromotive force, a method of concentrating the magnetic flux distribution is used, but there is a problem that cracks occur in the magnet as the magnetic flux distribution is concentrated.

[0012] Prior art literature

[0013] Patent Document 1: Korean Publication Patent No. KR10-2020-0089604 Summary of the invention

[0014] An object of the present invention is to provide a magnet capable of increasing the back electromotive force of a motor while reducing the possibility of cracks in the magnet, a motor including the magnet, and a washing machine including the motor.

[0015] In addition, an object of the present invention is to provide a magnet capable of improving the back electromotive force of a motor while saving the material cost of the motor, a motor including the magnet, and a washing machine including the motor.

[0016] Another object of the present invention is to provide a magnet capable of improving the space efficiency of a motor suitable for a washing machine, a motor including the magnet, and a washing machine including the motor.

[0017] A magnet according to one aspect of the present invention for achieving the above-mentioned object comprises: at least one pole region, at least one of the pole regions is formed into a circular arc shape and arranged side by side along the circumferential direction, and at least one of the pole regions has a respective magnetic focus center different from the center of the inner diameter of at least one of the pole regions.

[0018] In this case, at least one of the polar regions may satisfy the following mathematical formula,

[0019] Here, d m is the distance from a straight line connecting the two ends of the magnetic center line of at least one of the polar regions to the central region of the magnetic center line of at least one of the polar regions, d b It is the distance from the straight line connecting the two ends of the magnetic center line of at least one polar region to the central area of ​​the magnetic center line of at least one polar region when at least one polar region has a magnetic focus center that is the same as the center of the inner diameter of at least one polar region.

[0020] In addition, when at least one of the pole regions is one, X < 7.5 can be satisfied; when at least one of the pole regions is two, X < 6 can be satisfied; when at least one of the pole regions is three, X < 4.5 can be satisfied; and when at least one of the pole regions is four, X < 3.5 can be satisfied.

[0021] Thus, it is possible to increase the back electromotive force of the motor while reducing the possibility of cracks occurring in the magnet.

[0022] In addition, d b can satisfy the mathematical formula

[0023] Here, r i can be the inner radius of at least one of the pole regions, and r o can be the outer radius of at least one of the pole regions, and p can be the number of at least one pole region.

[0024] In addition, when at least one of the pole regions is one, 6 < X can be satisfied; when at least one of the pole regions is two, 4.5 < X can be satisfied; when at least one of the pole regions is three, 3.5 < X can be satisfied; and when at least one of the pole regions is four, 2.5 < X can be satisfied.

[0025] Thus, it is possible to increase the back electromotive force of the motor while saving the material cost of the motor.

[0026] In addition, when at least one of the pole regions is plural, the distances between each of the magnetic focus centers and at least one of the pole regions can be the same. In this case, the circumferential distances between each of the plural magnetic focus centers can be the same. Furthermore, adjacent pole regions can have different polarities from each other.

[0027] The motor according to one aspect of the present invention for achieving the above object may include: a stator; and a rotor including a rotor core and a plurality of magnets, the rotor core being disposed radially outside the stator, and the plurality of magnets being disposed on the inner side surface of the rotor core facing the stator.

[0028] In this case, each of the plurality of magnets includes at least one pole region, at least one of the pole regions is formed in an arc shape and arranged side by side in the circumferential direction, and at least one of the pole regions may have respective magnetic focus centers different from the center of the inner diameter of at least one of the pole regions.

[0029] In addition, at least one pole region can satisfy the mathematical formula

[0030] Here, dm It can be the distance from the straight line connecting the two ends of the magnetic center line of at least one of the polar regions to the central area of ​​the magnetic center line of at least one of the polar regions, d b It can be the distance from the straight line connecting the two ends of the magnetic center line of at least one polar region to the central area of ​​the magnetic center line of at least one polar region when at least one polar region has a magnetic focus center that is the same as the center of the inner diameter of at least one polar region.

[0031] In this case, when at least one of the polar regions is one, X<7.5 can be satisfied, when at least one of the polar regions is two, X<6 can be satisfied, when at least one of the polar regions is three, X<4.5 can be satisfied, and when at least one of the polar regions is four, X<3.5 can be satisfied.

[0032] This can increase the back electromotive force of the motor and reduce the possibility of cracks in the magnet.

[0033] In addition, when at least one of the polar regions is one, the plurality of the magnets can be 48, when at least one of the polar regions is two, the plurality of the magnets can be 24, when at least one of the polar regions is three, the plurality of the magnets can be 16, and when at least one of the polar regions is four, the plurality of the magnets can be 12.

[0034] This can improve the space efficiency of the motor used in the washing machine.

[0035] According to the present invention, a magnet capable of increasing the back electromotive force of a motor while reducing the possibility of cracks in the magnet, a motor including the magnet, and a washing machine including the motor can be provided.

[0036] In addition, through the present invention, a magnet capable of improving the back electromotive force of the motor while saving the material cost of the motor, a motor including the magnet, and a washing machine including the motor can be provided.

[0037] In addition, according to the present invention, a magnet capable of improving the space efficiency of a motor applicable to a washing machine, a motor including the magnet, and a washing machine including the motor can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 and Figure 2 It is a three-dimensional diagram of a washing machine according to an embodiment of the present invention.

[0039] Figure 3 1 is a perspective view of a driving system for a washing machine according to an embodiment of the present invention.

[0040] Figure 4 1 is an exploded perspective view of a washing machine driving system according to an embodiment of the present invention.

[0041] Figure 5 2 is an exploded perspective view of a driving system for a washing machine according to another embodiment of the present invention.

[0042] Figure 6 FIG. 1 is a top view of a rotor according to an embodiment of the present invention.

[0043] Figures 7 to 10 FIG. 1 is a top view of a magnet according to an embodiment of the present invention.

[0044] Fig.11 FIG. 1 is a top view of a rotor according to an embodiment of the present invention.

[0045] Fig.12 Is magnification Fig.11 Figure 1.

[0046] Fig.13 FIG. 1 is a top view of a polar region according to an embodiment of the present invention.

[0047] Fig.14 This is a graph showing the rate of increase of the back electromotive force of a motor corresponding to the polar anisotropy coefficient of a magnet according to one embodiment of the present invention.

[0048] Fig.15 This is a graph showing the material cost change rate of the stator corresponding to the polar anisotropy coefficient of the magnet according to one embodiment of the present invention.

[0049] Fig.16 This is a graph showing the ratio of rotor manufacturing cost corresponding to the number of pole regions in one magnet according to one embodiment of the present invention.

[0050] Fig.17 This is a graph showing the rate of change in material cost of a motor with respect to the polar anisotropy coefficient of a magnet according to an embodiment of the present invention.

[0051] Fig.18 This is a graph showing the rate of increase of the back electromotive force of a motor corresponding to the polar anisotropy coefficient of a magnet according to one embodiment of the present invention.

[0052] Description of Reference Numerals

[0053] 10: Washing machine 20: External tank

[0054] 100: Washing machine drive system 110: Output shaft

[0055] 120: Housing 130: First bearing

[0056] 140: Second bearing 150: Stator

[0057] 160: rotor 162: magnet

[0058] 164: Rotor core 170: Planetary gear set

[0059] 180: Clutch DETAILED DESCRIPTION

[0060] Hereinafter, embodiments disclosed in the present invention will be described in detail with reference to the accompanying drawings, and the same or similar components are given the same reference numerals regardless of the figure numbers, and repeated description thereof will be omitted.

[0061] In the process of describing the embodiments disclosed in the present invention, if it is mentioned that a certain component is "connected" or "linked" to another component, it should be understood that it may be directly connected or linked to the other component, but other components may also be present between them.

[0062] In addition, in the process of describing the embodiments disclosed in the present invention, if it is determined that the specific description of the relevant known technology makes the gist of the embodiments disclosed in the present invention unclear, the detailed description thereof will be omitted. In addition, the drawings are only for helping to understand the embodiments disclosed in the present invention, and the technical ideas disclosed in the present invention are not limited by the drawings, and should be understood to include all changes, equivalents and substitutes within the ideas and technical scope of the present invention.

[0063] In addition, the term disclosure may be replaced by the terms document, specification, description, etc.

[0064] Figure 1 and Figure 2 It is a three-dimensional diagram of a washing machine according to an embodiment of the present invention.

[0065] Reference Figure 1 and Figure 2 The washing machine 10 of one embodiment of the present invention may include an outer tub 20 and a washing machine driving system 100, and may be implemented by removing a portion of the components, and additional components other than the outer tub 20 are not excluded.

[0066] The washing machine 10 of one embodiment of the present invention is described as an example of a front-loading type washing machine in which the rotation center of the inner tank is designed to be formed in a direction horizontal to the floor or inclined in a direction descending as it approaches the rear end, and the laundry can be loaded from the front, but the detailed structure of the washing machine drive system 100 can also be applied to top-loading washing machines.

[0067] The outer tank 20 may be in the shape of a cylinder with an upper portion or a front portion open. An inner tank (not shown) may be disposed inside the outer tank 20. The outer tank 20 may be formed of a plastic material. The inner tank may be connected to the output shaft 110 of the washing machine drive system 100. The washing machine drive system 100 is coupled to the inner tank of the washing machine 10 to rotate the inner tank.

[0068] Figure 3 1 is a perspective view of a driving system for a washing machine according to an embodiment of the present invention. Figure 4 1 is an exploded perspective view of a washing machine driving system according to an embodiment of the present invention. Figure 5 2 is an exploded perspective view of a driving system for a washing machine according to another embodiment of the present invention. Figure 6 FIG. 1 is a top view of a rotor according to an embodiment of the present invention.

[0069] Reference Figure 3 , Figure 4 as well as Figure 6 A washing machine driving system 100 according to an embodiment of the present invention may include an output shaft 110, a housing 120, a first bearing 130, a second bearing 140, a stator 150, a rotor 160, a planetary gear set 170, and a clutch 180. It may also be implemented by removing some of the components, and additional components other than these are not excluded.

[0070] like Figure 5 As shown, the washing machine driving system 100 may also be implemented without the planetary gear set 170 and the clutch 180 .

[0071] The output shaft 110 may extend in the axial direction. The output shaft 110 may be coupled to the inner groove. The output shaft 110 may be rotatably coupled to the housing 120. The output shaft 110 may be coupled to the housing 120 via a bearing. The output shaft 110 may be coupled to the planetary gear set 170.

[0072] An inner groove may be combined in the upper region of the output shaft 110. The central region of the output shaft 110 may be combined with the housing 120 via a bearing. A first bearing 130 and a second bearing 140 may be disposed between the central region of the output shaft 110 and the housing 120.

[0073] The lower region of the output shaft 110 may be disposed inside the rotor 160. The lower region of the output shaft 110 may be coupled to the planetary gear set 170. The diameter of the lower region of the output shaft 110 may be formed to be smaller than the diameter of the central region. The axial length of the lower region of the output shaft 110 may be formed to be shorter than the axial length of the central region of the output shaft 110.

[0074] The output shaft 110 may be rotatably coupled to the housing 120. An inner groove and an outer groove 20 may be disposed at an upper portion of the housing 120. The housing 120 may be coupled to the outer groove 20. A stator 150, a rotor 160, a planetary gear set 170, and a clutch 180 may be disposed at a lower portion of the housing 120. The housing 120 may be coupled to the stator 150. The housing 120 may be formed of a plastic material.

[0075] The first bearing 130 may be disposed between the output shaft 110 and the housing 120. The first bearing 130 may couple the output shaft 110 to the housing 120 through a bearing. The first bearing 130 may rotatably couple the output shaft 110 to the housing 120. The first bearing 130 may extend in a circumferential direction. The first bearing 130 may be disposed above the second bearing 140.

[0076] The second bearing 140 may be disposed between the output shaft 110 and the housing 120. The second bearing 140 may couple the output shaft 110 to the housing 120 through a bearing. The second bearing 140 may rotatably couple the output shaft 110 to the housing 120. The second bearing 140 may extend in the circumferential direction. The second bearing 140 may be disposed below the first bearing 130. The second bearing 140 may be disposed above the planetary gear set 170. The second bearing 140 may be disposed radially inward of the stator 150.

[0077] The stator 150 may be coupled to the housing 120. The stator 150 may be disposed inside the rotor 160. The stator 150 may face the rotor 160. The stator 150 may be disposed above the clutch 180. The stator 150 may include: a coupling portion coupled to the housing 120; a stator disposed radially outside the coupling portion; and a coil wound around the stator. The stator 150 may rotate the rotor 160 through electromagnetic interaction.

[0078] The rotor 160 may face the stator 150. The rotor 160 may be combined with the planetary gear set 170. Thus, the rotor 160 may supply a rotational force to the output shaft 110.

[0079] The rotor 160 may include a rotor core 164 disposed radially outside the stator 150, and a magnet 162 disposed on an inner side of the rotor core 164. The magnet 162 may face the stator 150. The magnet 162 may face the stator of the stator 150. When current is supplied to the coil of the stator 150, the magnet 162 may rotate in one direction or the other through electromagnetic interaction.

[0080] The magnet 162 may include a plurality of magnets spaced apart in the circumferential direction, and the plurality of magnets may be radially arranged with the central region of the rotor core 164 as a reference, and the plurality of magnets may respectively face a plurality of stators spaced apart in the circumferential direction.

[0081] The stator 150 and the rotor 160 may be referred to as a “motor”.

[0082] The planetary gear set 170 may be spline-coupled to the outer circumferential surface of the output shaft 110. The planetary gear set 170 may be coupled to the rotor 160. The planetary gear set 170 may rotate integrally with the rotor 160. The planetary gear set 170 may transmit the rotational force of the rotor 160 to the output shaft 110.

[0083] For example, the planetary gear set 170 can transmit the rotational force of the rotor 160 to the output shaft 110 at a gear ratio of 1:1 or n:1, or can transmit the rotational force of the rotor 160 to the output shaft 110 at a gear ratio of 1:1. Thus, the washing mode and the dehydration mode can be realized without a stop action between the completion of washing and the start of dehydration.

[0084] The clutch 180 may be disposed between the motors 150 and 160 and the planetary gear set 170. A portion of the clutch 180 may be splined with the planetary gear set 170, and another portion may be coupled to the stator 150. The clutch 180 may fix or release a portion of the planetary gear set 170. Thus, the clutch 180 may enable the planetary gear set 170 to transmit the rotational force of the rotor 160 to the output shaft 110 at a 1:1 ratio or transmit it to the output shaft 110 at a reduced gear ratio of n:1.

[0085] Figures 7 to 10 FIG. 1 is a top view of a magnet according to an embodiment of the present invention. Fig.11 FIG. 1 is a top view of a rotor according to an embodiment of the present invention. Fig.12 Is magnification Fig.11 Figure 1.

[0086] like Figure 5 As shown, the magnet 162 according to an embodiment of the present invention may also be applicable to a washing machine 10 driven without the planetary gear set 170 and the clutch 180 .

[0087] Reference Figure 7, the magnet 162 may include single pole regions 1622, 1623. The single pole regions 1622, 1623 may be spaced apart in the circumferential direction. The single pole regions 1622, 1623 may be arranged side by side in the circumferential direction. The single pole regions 1622, 1623 arranged adjacent to each other may have different polarities from each other. For example, the inner side surface of the first pole region 1622 may have an N pole, and the inner side surface of the second pole region 1623 spaced apart from the first pole region 1622 in the circumferential direction may have an S pole.

[0088] The individual polar regions 1622 and 1623 may be formed in an arc shape as a whole. The adjacent individual polar regions 1622 and 1623 may have an inner diameter r of the individual polar regions 1622 and 1623. i The center O of each magnetic focus center b1 and b2 are different. For example, the first magnetic focus center b1 may be the first magnetic orientation m of the first pole region 1622. a The second magnetic focus center b2 may be the second magnetic orientation m of the second pole region 1623. b The distance r between the magnetic focus centers b1 and b2 of the adjacent single pole regions 1622 and 1623 and the single pole regions 1622 and 1623 b Can be identical to each other.

[0089] In one embodiment of the present invention, the case where the magnet 162 is formed of a single pole region 1622, 1623 may be defined as a "single-pole magnet".

[0090] Reference Figure 8 , the magnet 162 may include two polar regions 1624, 1625. The two polar regions 1624, 1625 may be arranged side by side in the circumferential direction. The two polar regions 1624, 1625 may have different polarities from each other. For example, the inner side surface of the third polar region 1624 may have an N pole, and the inner side surface of the fourth polar region 1625 may have an S pole.

[0091] The two polar regions 1624 and 1625 may be formed in an arc shape as a whole. The two adjacent polar regions 1624 and 1625 may have an inner diameter r of the two polar regions 1624 and 1625. i The third magnetic focus center b3 and b4 are different from the center O of the third pole region 1624. For example, the third magnetic focus center b3 may be the third magnetic orientation m c The fourth magnetic focus center b4 may be the fourth magnetic orientation m of the fourth pole region 1625. d The distance r between the magnetic focal centers b3 and b4 of the two polar regions 1624 and 1625 and the two polar regions 1624 and 1625 bThe circumferential distances between the plurality of magnetic focus centers adjacent to the magnetic focus centers b3 and b4 of the two pole regions 1624 and 1625 may be the same as each other.

[0092] In one embodiment of the present invention, the case where the magnet 162 is formed by two polar regions 1624 and 1625 can be defined as a “two-pole magnet”.

[0093] Reference Fig. 9 , the magnet 162 may include three pole regions 1626, 1627, 1628. The three pole regions 1626, 1627, 1628 may be arranged side by side in the circumferential direction. The three pole regions 1626, 1627, 1628 may have different polarities from each other. For example, the inner side surface of the fifth pole region 1626 may have an N pole, the inner side surface of the sixth pole region 1627 may have an S pole, and the inner side surface of the seventh pole region 1628 may have an N pole.

[0094] The three polar regions 1626, 1627, 1628 may be formed in an arc shape as a whole. The three adjacent polar regions 1626, 1627, 1628 may have an inner diameter r of the three polar regions 1626, 1627, 1628. i The center O of each magnetic focus center b5, b6, and b7 are different. For example, the fifth magnetic focus center b5 may be the fifth magnetic orientation m of the fifth pole region 1626. e The sixth magnetic focus center b6 may be the sixth magnetic orientation m of the sixth pole region 1627. f The seventh magnetic focus center b7 may be the seventh magnetic orientation m of the seventh pole region 1628. g The distance r between the magnetic focus centers b5, b6, and b7 of the three polar regions 1626, 1627, and 1628 and the three polar regions 1626, 1627, and 1628 b The circumferential distances between the plurality of magnetic focus centers adjacent to the magnetic focus centers b5, b6, and b7 of the three pole regions 1626, 1627, and 1628 may be the same as each other.

[0095] In one embodiment of the present invention, the situation where the magnet 162 is formed by three polar regions 1626 , 1627 , 1628 may be defined as a “three-pole magnet”.

[0096] Reference Figures 10 to 12, the magnet 162 may include four pole regions 1629, 1630, 1631, 1632. The four pole regions 1629, 1630, 1631, 1632 may be arranged side by side in the circumferential direction. The four pole regions 1629, 1630, 1631, 1632 may have different polarities from each other. For example, the inner side surface of the eighth pole region 1629 may have an N pole, the inner side surface of the ninth pole region 1630 may have an S pole, the inner side surface of the tenth pole region 1631 may have an N pole, and the inner side surface of the eleventh pole region 1632 may have an S pole. The four pole regions 1629, 1630, 1631, 1632 may be formed in an arc shape as a whole.

[0097] The four adjacent polar regions 1629, 1630, 1631, 1632 may have an inner diameter r of the four polar regions 1629, 1630, 1631, 1632. i The center O of each magnetic focus center b8, b9, b10, b11 is different from the center O of each magnetic focus center. For example, the eighth magnetic focus center b8 may be the eighth magnetic orientation m of the eighth pole region 1629. h The ninth magnetic focal center b9 may be the ninth magnetic orientation m of the ninth pole region 1630. i The tenth magnetic focal center b10 may be the tenth magnetic orientation m of the tenth pole region 1631. j The eleventh magnetic focus center b11 may be the eleventh magnetic orientation m of the eleventh pole region 1632. k center of focus.

[0098] In this case, the distances r between the magnetic focus centers b8, b9, b10, b11 of the four polar regions 1629, 1630, 1631, 1632 and the four polar regions 1629, 1630, 1631, 1632 are b The circumferential distances between the plurality of magnetic focus centers adjacent to the magnetic focus centers b8, b9, b10, and b11 of the four pole regions 1629, 1630, 1631, and 1632 may be the same as each other.

[0099] In one embodiment of the present invention, the situation where the magnet 162 is formed by four polar regions 1629 , 1630 , 1631 , 1632 may be defined as a “quadrupole magnet”.

[0100] In one embodiment of the present invention, when there is one at least one polar region 1622, 1623, the number of the plurality of magnets spaced apart in the circumferential direction may be 48, when there are two at least one polar region 1624, 1625, the number of the plurality of magnets spaced apart in the circumferential direction may be 24, when there are three at least one polar region 1626, 1627, 1628, the number of the plurality of magnets spaced apart in the circumferential direction may be 16, and when there are four at least one polar region 1629, 1630, 1631, 1632, the number of the plurality of magnets spaced apart in the circumferential direction may be 12. Thus, the space efficiency of the motors 150, 160 applicable to the washing machine 10 can be improved.

[0101] In one embodiment of the present invention, the case where the number of at least one polar region 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632 is one to four is described as an example, but the case where there are more than five polar regions is not excluded.

[0102] Fig.13 FIG. 1 is a top view of a polar region according to an embodiment of the present invention.

[0103] Reference Fig.13 , the anisotropic coefficient X is explained.

[0104] d m It refers to the distance between the straight line L2 connecting the two ends of the magnetic center line m2 of at least one polar region 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632 and the central area of ​​the magnetic center line m2 of at least one polar region 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632.

[0105] d b It means that at least one polar region 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632 has an inner diameter r of at least one polar region 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632. iWhen the center O is the same as the magnetic focus center, the distance between the straight line L1 connecting the two ends of the magnetic center line m1 of at least one polar region 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632 and the central area of ​​the magnetic center line m1 of at least one of the polar regions 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632.

[0106] exist Fig.13 Medium, d m and d b The illustration is based on the vertical lines separating the left and right sides, but this is only to help understand. In fact, d m and d b It can be interpreted as the meaning of the length based on the overlapping vertical lines.

[0107] Here, d b Mathematical formula 1 can be satisfied.

[0108] [Mathematical formula 1]

[0109]

[0110] Here, r i It may refer to the inner radius of at least one polar region 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632, r o 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632 and p may refer to the number of poles of at least one polar region 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632.

[0111] The polar anisotropy coefficient X is a coefficient that determines the proximity of the magnetic focus center of at least one polar region 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632 to at least one polar region 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632, and can satisfy the following mathematical formula 2.

[0112] [Mathematical formula 2]

[0113]

[0114] Fig.14 This is a graph showing the rate of increase of the back electromotive force of a motor corresponding to the polar anisotropy coefficient of a magnet according to one embodiment of the present invention.

[0115] Reference Fig.14 , it can be seen that the back electromotive force increase rate corresponding to the polar anisotropy coefficient X of the magnet 162. The back electromotive force increase rate of the motors 150 and 160 increases as the polar anisotropy coefficient X of the magnet 162 increases. Here, the back electromotive force increase rate refers to the ratio of the back electromotive force when the polar anisotropy coefficient changes to the back electromotive force when the polar anisotropy coefficient X is 1. The closer the magnetic focus center b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11 of at least one polar region 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632 is to at least one polar region 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632, the higher the polar anisotropy coefficient X can be.

[0116] As the polar anisotropy coefficient X increases, the directional guide (the electronic arrangement of the magnetic body) concentrates at the circumferential center of the polar region and the rigidity of the circumferential end portions of the polar region decreases, so that the magnet 162 may crack. In other words, if the polar anisotropy coefficient X continues to increase, the magnet 162 may crack.

[0117] Specifically, if the polar anisotropy coefficient X reaches 7.5 when the magnet 162 is a one-pole magnet, the magnet 162 may crack; if the polar anisotropy coefficient X reaches 6 when the magnet 162 is a two-pole magnet, the magnet 162 may crack; if the polar anisotropy coefficient X reaches 4.5 when the magnet 162 is a three-pole magnet, the magnet 162 may crack; if the polar anisotropy coefficient X reaches 3.5 when the magnet 162 is a four-pole magnet, the magnet 162 may crack.

[0118] Therefore, preferably, when there is one at least one polar region 1622, 1623 of the magnet 162, the polar anisotropy coefficient X is less than 7.5, when there are two at least one polar region 1624, 1625, the polar anisotropy coefficient X is less than 6, when there are three at least one polar region 1626, 1627, 1628, the polar anisotropy coefficient X is less than 4.5, and when there are four at least one polar region 1629, 1630, 1631, 1632, the polar anisotropy coefficient X is less than 3.5.

[0119] Thus, the possibility of cracks in the magnet 162 is reduced while increasing the back electromotive force of the motors 150 and 160, thereby preventing product damage.

[0120] Fig.15 This is a graph showing the material cost change rate of the stator corresponding to the polar anisotropy coefficient of the magnet according to one embodiment of the present invention. Fig.16 This is a graph showing the rate of change in rotor manufacturing cost with respect to the number of pole regions in one magnet according to one embodiment of the present invention. Fig.17 This is a graph showing the rate of change in material cost of a motor with respect to the polar anisotropy coefficient of a magnet according to an embodiment of the present invention. Fig.18 This is a graph showing the rate of increase of the back electromotive force of a motor corresponding to the polar anisotropy coefficient of a magnet according to one embodiment of the present invention.

[0121] exist Fig.14 In FIG. 1 , it is confirmed that the back electromotive force of the motors 150 and 160 increases with the increase of the polar anisotropy coefficient X. Generally, in the core of the same rotor 160 , the smaller the stacking height of the stator core is, the smaller the back electromotive force of the motor is.

[0122] When the polar anisotropy coefficient X is increased to 1 or more, the stacking height of the stator core can be reduced to achieve the same level of back electromotive force as when the polar anisotropy coefficient X is 1. That is, when the polar anisotropy coefficient X is 1 or more, the material cost of the stator can be reduced by reducing the stacking height of the stator core.

[0123] Reference Fig.15 , it can be seen that the material cost change rate of the stator of the motor 150, 160 is based on the polar anisotropy coefficient X of the motor 150, 160. It can be seen that the back electromotive force of the motor 150, 160 increases with the increase of the polar anisotropy coefficient X, and the stacking of the stator of the motor 150, 160 can be reduced, so the material cost of the stator can be reduced. Here, the material cost ratio of the stator refers to the ratio of the stator material cost when the polar anisotropy coefficient X changes to the stator material cost when the polar anisotropy coefficient X is 1.

[0124] Reference Fig.16 , it can be seen that the number of pole regions 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632 in one magnet corresponds to the ratio of the manufacturing cost of the rotor 160. Here, the ratio of the manufacturing cost of the rotor 160 refers to the ratio of the manufacturing cost of the rotor when the number of pole regions in one magnet 162 is less than six to the manufacturing cost of the rotor 160 when one magnet 162 is composed of six pole regions.

[0125] Even if the number of pole regions 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632 of one magnet 162 in a rotor 160 of the same size changes, the overall mass of the magnets 162 in the rotor 160 will not change significantly.

[0126] However, the greater the number of pole regions 1622 , 1623 , 1624 , 1625 , 1626 , 1627 , 1628 , 1629 , 1630 , 1631 , 1632 in one magnet 162 , the smaller the number of physical magnets 162 within the rotor 160 . For example, when there is one pole region 1622, 1623 in a magnet 162, 48 physical magnets 162 of the rotor 160 are required, when there are two pole regions 1624, 1625 in a magnet 162, 24 physical magnets 162 of the rotor 160 are required, when there are three pole regions 1626, 1627, 1628 in a magnet 162, 16 physical magnets 162 of the rotor 160 are required, when there are four pole regions 1629, 1630, 1631, 1632 in a magnet 162, 12 physical magnets 162 of the rotor 160 are required, and when there are six pole regions in a magnet 162, 8 physical magnets 162 of the rotor 160 are required.

[0127] As the number of physical magnets 162 of the rotor 160 increases, the number of work steps required to attach the magnets 162 to the inner side of the rotor core 164 increases, and thus the work cost also increases. In other words, it can be considered that as the number of pole regions 1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632 in one magnet 162 decreases, the manufacturing cost of the rotor 160 increases.

[0128] Reference Fig.17 , it can be seen that the material cost ratio of the motors 150 and 160 corresponding to the polar anisotropy coefficient X of the magnet 162. The material cost of the motors 150 and 160 can be understood as including Fig.15 The material cost of the stator and Fig.16 The manufacturing cost of the rotor 160 described in .

[0129] exist Fig.17It can be seen that, based on 100% of the material cost of motors 150 and 160, in one magnet 162, the polar anisotropy coefficient X is 6 when there are one pole region 1622 and 1623, the polar anisotropy coefficient X is 4.5 when there are two pole regions 1624 and 1625, the polar anisotropy coefficient X is 3.5 when there are three pole regions 1626, 1627, and 1628, and the polar anisotropy coefficient X is 2.5 when there are four pole regions 1629, 1630, 1631, and 1632.

[0130] It can be seen that if the polar anisotropy coefficient X exceeds 6 when at least one polar region 1622, 1623 is one, the polar anisotropy coefficient X exceeds 4.5 when at least one polar region 1624, 1625 is two, the polar anisotropy coefficient X exceeds 3.5 when at least one polar region 1626, 1627, 1628 is three, and the polar anisotropy coefficient X exceeds 2.5 when at least one polar region 1629, 1630, 1631, 1632 is four, the material cost of motors 150, 160 can be reduced to less than 100%. This means that the lowest critical value for setting the polar anisotropy coefficient X is within the limited material cost of motors 150, 160.

[0131] Therefore, refer to Fig.18 Considering that the magnet 162 does not crack and the material cost of the motors 150 and 160 is limited, the polar anisotropy coefficient X is designed to be between 6 and 7.5 when at least one polar region 1622, 1623 is 1, the polar anisotropy coefficient X is between 4.5 and 6 when at least one polar region 1624, 1625 is two, the polar anisotropy coefficient X is between 3.5 and 4.5 when at least one polar region 1626, 1627, 1628 is three, and the polar anisotropy coefficient X is between 2.5 and 3.5 when at least one polar region 1629, 1630, 1631, 1632 is four. It can be said that the orientation of the magnet 162 with the optimal polar anisotropy coefficient X is achieved.

[0132] The aforementioned certain embodiments or other embodiments of the present invention are not mutually exclusive or distinct. The various components or functions of the aforementioned certain embodiments or other embodiments of the present invention may be mixed or combined.

[0133] For example, this means that the A configuration described in a specific embodiment and / or drawing can be combined with the B configuration described in another embodiment and / or drawing. In other words, it means that even if the combination between the configurations is not directly described, they can be combined except for the case where it is described that they cannot be combined.

[0134] The above detailed description should not be interpreted as limiting in all aspects, but should be considered as illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.

Claims

1. A magnet, wherein: include: At least one polar region is formed in an arc shape and arranged side by side along the circumferential direction, at least one of the polar regions has a respective magnetic focus center that is different from a center of an inner diameter of at least one of the polar regions, At least one of the polar regions satisfies the following mathematical formula, Here, d m is the distance from a straight line connecting the two ends of the magnetic center line of at least one of the polar regions to the central region of the magnetic center line of at least one of the polar regions, d b is the distance from a straight line connecting the two ends of the magnetic center line of at least one of the polar regions to the central area of ​​the magnetic center line of at least one of the polar regions, when at least one of the polar regions has a magnetic focus center that is the same as the center of the inner diameter of at least one of the polar regions, In the case where at least one of the polar regions is one, X<7.5 is satisfied, In the case where at least one of the polar regions is two, X<6 is satisfied, In the case where at least one of the polar regions is three, X<4.5 is satisfied, When at least one of the polar regions is four, X<3.5 is satisfied.

2. The magnet according to claim 1, wherein d b Satisfies the following mathematical formula, Here, r i is the inner radius of at least one of the polar regions, r o is the outer radius of at least one of the polar regions, and p is the number of at least one of the polar regions.

3. The magnet according to claim 1, wherein In the case where at least one of the polar regions is one, 6 is satisfied <X, In the case where at least one of the polar regions is two, 4.5 is satisfied <X, In the case where at least one of the polar regions is three, 3.5 is satisfied <X, In the case where at least one of the polar regions is four, 2.5 is satisfied <X。 4. The magnet according to claim 1, wherein at least one of the polar regions is plural, The distances between the respective centers of the magnetic focal points and at least one of the pole regions are identical to each other.

5. The magnet according to claim 1, wherein at least one of the polar regions is plural, The circumferential distances between the centers of the plurality of respective magnetic focal points are the same as each other.

6. The magnet according to claim 1, wherein When at least one of the polar regions is in plural, adjacent polar regions have different polarities from each other.

7. A magnet, wherein: include: At least one polar region is formed in an arc shape and arranged side by side along the circumferential direction, at least one of the polar regions has a respective magnetic focus center that is different from a center of an inner diameter of at least one of the polar regions, At least one of the polar regions satisfies the following mathematical formula, Here, d m is the distance from a straight line connecting the two ends of the magnetic center line of at least one of the polar regions to the central region of the magnetic center line of at least one of the polar regions, d b is the distance from a straight line connecting the two ends of the magnetic center line of at least one of the polar regions to the central area of ​​the magnetic center line of at least one of the polar regions, when at least one of the polar regions has a magnetic focus center that is the same as the center of the inner diameter of at least one of the polar regions, In the case where at least one of the polar regions is one, 6 is satisfied <X, In the case where at least one of the polar regions is two, 4.5 is satisfied <X, In the case where at least one of the polar regions is three, 3.5 is satisfied <X, In the case where at least one of the polar regions is four, 2.5 is satisfied <X。 8. A motor, wherein: include: Stator; as well as The rotor comprises a rotor core and a plurality of magnets, wherein the rotor core is arranged on the radially outer side of the stator, and the plurality of magnets are arranged on the inner side surface of the rotor core and face the stator. The magnet is the magnet according to any one of claims 1 to 7.

9. The motor according to claim 8, wherein: In the case where at least one of the polar regions is one, the plurality of the magnets is 48, In the case where at least one of the polar regions is two, the plurality of the magnets is 24, In the case where at least one of the polar regions is three, the plurality of the magnets is 16, In the case where at least one of the pole regions is four, the plurality of the magnets is twelve.

10. A washing machine comprising the motor according to claim 8.

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