Magnet, motor including same, and washing machine including same

Abstract

Provided are a magnet, a motor including same, and a washing machine including the motor. A magnet, according to an aspect of the present specification, includes a plurality of polar regions formed in an arc shape and disposed side by side in the circumferential direction, each having chamfers formed on the ends thereof on the inner side, and a value obtained by dividing the length of the chamfers in the radial direction by the length of the polar regions in the radial direction is between 0.20 and 0.21.

Description

Magnet, motor including same, and washing machine including same

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

[0002] Typically, a washing machine includes an outer tub that holds laundry water, and an inner tub that is rotatable and accommodates laundry cloths such as clothes. As the inner tub rotates, laundry cloths are washed and dehydrated.

[0003] Washing machines can be classified into a top loading type in which the rotation center of the inner drum is formed in a direction perpendicular to the floor and laundry can be loaded from the top, and a front loading type in which the rotation center of the inner drum is formed in a direction inclined in a direction horizontal to the floor or in a direction that lowers toward the rear and laundry can be loaded from the front.

[0004] Top-loading washing machines can be broadly categorized into agitator type and pulsator type. Agitator type washes clothes by rotating a washing rod raised in the center of the inner tub, while vortex type washes clothes by rotating a disc-shaped pulsator formed at the bottom of the inner tub.

[0005] Front-loading washing machines are commonly called 'drum washing machines', and have a lifter on the inner surface of the drum. As the drum rotates, the lifter lifts and drops laundry, thereby performing the washing.

[0006] Washing machines operate in two main operating modes (wash mode and spin mode) with different operating conditions.

[0007] To meet both of the above two main operating modes, the washing machine is equipped with a clutch, which operates the output shaft at low speed and high torque with a gear ratio of n:1 (washing mode), or at high speed and low torque with a gear ratio of 1:1 (spin mode).

[0008] In this case, there is a structure that adds a planetary gear to reduce power consumption and improve the driving efficiency of the motor.

[0009] Washing machines are typically equipped with outer rotor motors. These motors have a stator with coils wound on the inside, and a rotor positioned radially outside the stator, with magnets surrounding the stator coils. The rotor contains multiple magnets arranged radially.

[0010] Before becoming a magnet, a typical magnetic material has electrons arranged randomly. To magnetize such a material, the electrons within the material are first aligned in a specific direction, and then an external magnetic field is applied to magnetically polarize it. This process allows the formation of a permanent magnet.

[0011] A method of concentrating the magnetic flux distribution is being used to increase the size of the counter electromotive force based on the same magnet usage, but there was a problem of cracks occurring in the magnet due to the concentration of the magnetic flux distribution.

[0012] Additionally, in the case of a magnet having multiple pole areas, there was a problem of lower performance compared to a magnet having a single pole due to the magnetic dividing area connecting the multiple pole areas and the physical dividing area at both ends of the magnet.

[0013] The problem to be solved by this specification is to provide a magnet that can increase the counter electromotive force of the motor while reducing the possibility of cracks occurring in the magnet, a motor including the magnet, and a washing machine including the magnet.

[0014] In addition, the problem to be solved by the present specification is to provide a magnet capable of reducing the cogging torque of a motor and improving the counter electromotive force of the motor, a motor including the magnet, and a washing machine including the magnet.

[0015] According to one aspect of the present specification for achieving the above task, a magnet may be formed in an arc shape and include a plurality of pole areas arranged in parallel in a circumferential direction.

[0016] In this case, a chamfer may be formed on the inner surface of both ends of the above-mentioned polar region.

[0017] Through this, the cogging torque of the motor can be reduced and the counter electromotive force of the motor can be improved.

[0018] Additionally, the value of the radial length of the chamfer divided by the radial length of the pole region may be between 0.20 and 0.21. Preferably, the value of the radial length of the chamfer divided by the radial length of the pole region may be between 0.208 and 0.209.

[0019] Additionally, the value of the circumferential length of the chamfer divided by the circumferential length of the polar region may be between 0.19 and 0.20. Preferably, the value of the circumferential length of the chamfer divided by the circumferential length of the polar region may be between 0.193 and 0.194.

[0020] Additionally, the cross section of the chamfer can be formed in a straight or curved shape.

[0021] According to an aspect of the present specification for achieving the above task, a magnet is formed in an arc shape and includes a plurality of pole regions arranged in parallel in a circumferential direction, and the plurality of pole regions can have their respective magnetic focus centers different from the centers of the inner diameters of the plurality of pole regions.

[0022] In this case, a chamfer may be formed on the inner surface of both ends of the above-mentioned polar region.

[0023] Through this, the cogging torque of the motor can be reduced and the counter electromotive force of the motor can be improved.

[0024] Additionally, the value of the radial length of the chamfer divided by the radial length of the pole region may be between 0.16 and 0.17. Preferably, the value of the radial length of the chamfer divided by the radial length of the pole region may be between 0.166 and 0.167.

[0025] Additionally, the value obtained by dividing the circumferential length of the chamfer by the circumferential length of the polar region may be between 0.155 and 0.165. Preferably, the value obtained by dividing the circumferential length of the chamfer by the circumferential length of the polar region may be between 0.1595 and 0.1605.

[0026] Additionally, the cross section of the chamfer can be formed in a straight or curved shape.

[0027] In addition, the above multiple polar regions are expressed by the following formula: can satisfy.

[0028] Here, d m is the distance from the straight line connecting the two ends of the magnetic center lines of the above plurality of polar regions to the central region of the magnetic center lines of the above plurality of polar regions, and d b is the distance from a straight line connecting both ends of the magnetic center lines of the plurality of polar regions to the central region of the magnetic center lines of the plurality of polar regions when the plurality of polar regions have magnetic focus centers that are the same as the centers of the inner diameters of the plurality of polar regions.

[0029] In addition, when the plurality of polar regions are two, X<6 can be satisfied, when the plurality of polar regions are three, X<4.5 can be satisfied, and when the plurality of polar regions are four, X<3.5 can be satisfied.

[0030] This increases the motor's counter electromotive force while reducing the possibility of cracks in the magnets.

[0031] A motor according to an aspect of the present specification for achieving the above task may include a stator, a rotor core disposed radially outside the stator, and a rotor including a plurality of magnets disposed on an inner surface of the rotor core and facing the stator.

[0032] A washing machine according to an aspect of the present specification for achieving the above task may include a motor.

[0033] The present specification provides a magnet capable of increasing the counter electromotive force of a motor while reducing the possibility of cracks occurring in the magnet, a motor including the same, and a washing machine including the same.

[0034] In addition, the present specification provides a magnet capable of reducing cogging torque of a motor and improving counter electromotive force of the motor, a motor including the same, and a washing machine including the same.

[0035] Figures 1 and 2 are perspective views of a washing machine according to one embodiment of the present specification.

[0036] FIG. 3 is a perspective view of a washing machine drive system according to one embodiment of the present specification.

[0037] FIG. 4 is an exploded perspective view of a washing machine drive system according to one embodiment of the present specification.

[0038] FIG. 5 is an exploded perspective view of a washing machine drive system according to another embodiment of the present specification.

[0039] Figure 6 is a plan view of a rotor according to one embodiment of the present specification.

[0040] Figures 7 to 10 are plan views of a magnet according to one embodiment of the present specification.

[0041] FIG. 11 is a plan view of a rotor according to one embodiment of the present specification.

[0042] Figure 12 is an enlarged view of part A of Figure 11.

[0043] FIG. 13 is a plan view of a polar region according to one embodiment of the present specification.

[0044] FIG. 14 is a graph showing the rate of increase in the counter electromotive force of a motor with respect to the polar anisotropy coefficient of a magnet according to one embodiment of the present specification.

[0045] FIG. 15 is a graph showing the change rate of the material cost of a stator with respect to the polar anisotropy coefficient of a magnet according to one embodiment of the present specification.

[0046] FIG. 16 is a graph showing the ratio of rotor manufacturing cost to the number of pole areas in one magnet according to one embodiment of the present specification.

[0047] FIG. 17 is a graph showing the change rate of the material cost of the motor with respect to the polar anisotropy coefficient of the magnet according to one embodiment of the present specification.

[0048] FIG. 18 is a graph showing the rate of increase in the counter electromotive force of a motor with respect to the polar anisotropy coefficient of a magnet according to one embodiment of the present specification.

[0049] Figures 19 to 21 are plan views of a magnet according to one embodiment of the present specification.

[0050] FIG. 22 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the radial length of the outer chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0051] FIG. 23 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the radial length of the outer chamfer of the pole area of ​​a magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0052] FIG. 24 is a graph showing the average of the weights of the motor according to the percentage of the radial length of the outer chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0053] FIG. 25 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the circumferential length of the outer chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0054] FIG. 26 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the circumferential length of the outer chamfer of the pole area of ​​a magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0055] FIG. 27 is a graph showing the average of the weights of the motor according to the percentage of the circumferential length of the outer chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0056] FIG. 28 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the radial length of the inner chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0057] FIG. 29 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the radial length of the inner chamfer of the pole area of ​​a magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0058] FIG. 30 is a graph showing the average of the weights of the motor according to the percentage of the radial length of the inner chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0059] FIG. 31 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the circumferential length of the inner chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0060] FIG. 32 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the circumferential length of the inner chamfer of the pole area of ​​a magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0061] FIG. 33 is a graph showing the average of the weights of the motor according to the percentage of the circumferential length of the inner chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0062] FIG. 34 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the radial length of the outer chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0063] FIG. 35 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the radial length of the outer chamfer of the pole area of ​​a magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0064] FIG. 36 is a graph showing the average of the weights of the motor according to the percentage of the radial length of the outer chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0065] FIG. 37 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the circumferential length of the outer chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0066] FIG. 38 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the circumferential length of the outer chamfer of the pole area of ​​a magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0067] FIG. 39 is a graph showing the average of the weights of the motor according to the percentage of the circumferential length of the outer chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0068] FIG. 40 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the radial length of the inner chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0069] FIG. 41 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the radial length of the inner chamfer of the pole area of ​​a magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0070] FIG. 42 is a graph showing the average of the weights of the motor according to the percentage of the radial length of the inner chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0071] FIG. 43 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the circumferential length of the inner chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0072] FIG. 44 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the circumferential length of the inner chamfer of the pole area of ​​a magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0073] FIG. 45 is a graph showing the average of the weights of the motor according to the percentage of the circumferential length of the inner chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0074] Fig. 46 is a graph showing the counter electromotive force of a motor according to a conventional method and an embodiment of the present specification.

[0075] Fig. 47 is a graph showing the cogging torque of a motor according to a conventional method and an embodiment of the present specification.

[0076] Hereinafter, the embodiments disclosed in this disclosure will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be given the same reference numbers and redundant descriptions thereof will be omitted.

[0077] When describing the embodiments disclosed herein, it should be understood that when a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to that other component, but there may also be other components present in between.

[0078] In addition, when describing the embodiments disclosed in this specification, if it is determined that a detailed description of a related known technology may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included within the spirit and technical scope of this specification.

[0079] Meanwhile, the term "discloser" can be replaced with terms such as "document," "specification," and "description."

[0080] Figures 1 and 2 are perspective views of a washing machine according to one embodiment of the present specification.

[0081] Referring to FIGS. 1 and 2, a washing machine (10) according to one embodiment of the present specification may include an outer tub (20) and a washing machine driving system (100), but may be implemented excluding some of these configurations, and additional configurations are not excluded.

[0082] A washing machine (10) according to one embodiment of the present specification is described as an example of a front-loading type in which the rotation center of the inner drum is formed to be inclined in a direction horizontal to the floor or in a direction lowering toward the rear end, and laundry can be loaded from the front. However, the detailed configuration of the washing machine drive system (100) can also be applied to a top-loading type washing machine.

[0083] The outer drum (20) may be cylindrical in shape with an open top or front. An inner drum (not shown) may be placed inside the outer drum (20). The outer drum (20) may be formed of a plastic material. The inner drum may be connected to the output shaft (110) of the washing machine drive system (100). The washing machine drive system (100) may be coupled to the inner drum of the washing machine (10) to rotate the inner drum.

[0084] FIG. 3 is a perspective view of a washing machine drive system according to one embodiment of the present disclosure. FIG. 4 is an exploded perspective view of a washing machine drive system according to one embodiment of the present disclosure. FIG. 5 is an exploded perspective view of a washing machine drive system according to another embodiment of the present disclosure. FIG. 6 is a plan view of a rotor according to one embodiment of the present disclosure.

[0085] Referring to FIGS. 3, 4, and 6, a washing machine drive system (100) according to one embodiment of the present specification 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), but may be implemented without some of these configurations, and additional configurations are not excluded.

[0086] As shown in Fig. 5, the washing machine drive system (100) may be implemented excluding the planetary gear set (170) and the clutch (180).

[0087] The output shaft (110) may extend axially. The output shaft (110) may be coupled to the inner body. The output shaft (110) may be rotatably coupled to the housing (120). The output shaft (110) may be bearing-coupled to the housing (120). The output shaft (110) may be coupled to a planetary gear set (170).

[0088] An inner ring may be coupled to the upper region of the output shaft (110). The central region of the output shaft (110) may be bearing-coupled to a housing (120). A first bearing (130) and a second bearing (140) may be arranged between the central region of the output shaft (110) and the housing (120).

[0089] The lower region of the output shaft (110) may be arranged inside the rotor (160). The lower region of the output shaft (110) may be coupled to a planetary gear set (170). The diameter of the lower region of the output shaft (110) may be formed smaller than the diameter of the central region. The axial length of the lower region of the output shaft (110) may be formed shorter than the axial length of the central region of the output shaft (110).

[0090] An output shaft (110) may be rotatably coupled to the housing (120). An inner drum and an outer drum (20) may be arranged on the upper portion of the housing (120). The housing (120) may be coupled to the outer drum (20). A stator (150), a rotor (160), a planetary gear set (170), and a clutch (180) may be arranged on the 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.

[0091] The first bearing (130) may be arranged between the output shaft (110) and the housing (120). The first bearing (130) may be configured to bear-couple the output shaft (110) to the housing (120). The first bearing (130) may be configured to rotatably couple the output shaft (110) to the housing (120). The first bearing (130) may extend in the circumferential direction. The first bearing (130) may be arranged above the second bearing (140).

[0092] 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) in a bearing manner. 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).

[0093] The stator (150) can be coupled to the housing (120). The stator (150) can be positioned inside the rotor (160). The stator (150) can face the rotor (160). The stator (150) can be positioned above the clutch (180). The stator (150) can include a coupling portion coupled to the housing (120), a stator positioned radially outside the coupling portion, and a coil wound around the stator. The stator (150) can rotate the rotor (160) through electromagnetic interaction.

[0094] The rotor (160) can face the stator (150). The rotor (160) can be coupled with a planetary gear set (170). Through this, the rotor (160) can supply rotational force to the output shaft (110).

[0095] The rotor (160) may include a rotor core (164) disposed radially outside the stator (150) and a magnet (162) disposed on the inner surface 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 direction due to electromagnetic interaction.

[0096] The magnet (162) may include a plurality of magnets spaced apart in the circumferential direction. The plurality of magnets may be arranged radially with respect to the central region of the rotor core (164). The plurality of magnets may each face a plurality of stators spaced apart in the circumferential direction.

[0097] The stator (150) and rotor (160) may be referred to as a 'motor'.

[0098] The planetary gear set (170) can be spline-coupled to the outer surface of the output shaft (110). The planetary gear set (170) can be coupled to the rotor (160). The planetary gear set (170) can rotate integrally with the rotor (160). The planetary gear set (170) can transmit the rotational power of the rotor (160) to the output shaft (110).

[0099] For example, the planetary gear set (170) can transmit the rotational force of the rotor (160) to the output shaft (110) by reducing it with a gear ratio of 1:1 or n:1, or transmit the rotational force of the rotor (160) to the output shaft (110) at 1:1. Through this, the washing mode and the dehydration mode can be implemented without a stopping operation between the end of washing and the start of dehydration.

[0100] A clutch (180) may be disposed between the motor (150, 160) and the planetary gear set (170). A portion of the clutch (180) may be spline-coupled to the planetary gear set (170), and another portion may be coupled to the stator (150). The clutch (180) may lock or unlock a portion of the planetary gear set (170). Through this, the clutch (180) may allow 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 to transmit it to the output shaft (110) at a reduced gear ratio of n:1.

[0101] Figures 7 to 10 are plan views of a magnet according to one embodiment of the present specification. Figure 11 is a plan view of a rotor according to one embodiment of the present specification. Figure 12 is an enlarged view of part A of Figure 11.

[0102] A magnet (162) according to one embodiment of the present specification can also be applied to a washing machine (10) driven without a planetary gear set (170) and a clutch (180), as shown in FIG. 5.

[0103] Referring to FIG. 7, the magnet (162) may include single-pole regions (1622, 1623). The single-pole regions (1622, 1623) may be spaced apart from each other in the circumferential direction. The single-pole regions (1622, 1623) may be arranged in parallel in the circumferential direction. The single-pole regions (1622, 1623) arranged adjacent to each other may have different polarities. For example, the inner surface of the first pole region (1622) may have a north pole, and the inner surface of the second pole region (1623) spaced apart from the first pole region (1622) in the circumferential direction may have a south pole.

[0104] The single pole region (1622, 1623) can be formed in an overall circular arc shape. The adjacent single pole region (1622, 1623) has an inner diameter (r-) of the single pole region (1622, 1623). i) may have different magnetic focal centers (b1, b2) from the center (O) of the first magnetic focal center. For example, the first magnetic focal center (b1) may have a first magnetic orientation (m) of the first polar region (1622). a ) may be the focus center, and the second magnetic focus center (b2) may be the second magnetic orientation (m) of the second pole region (1623). b ) may be the focus center. The distance (r) between the magnetic focus center (b1, b2) of the adjacent single-pole region (1622, 1623) and the single-pole region (1622, 1623) b ) can be identical to each other.

[0105] In one embodiment of the present specification, a case where a magnet (162) is formed as a single pole region (1622, 1623) can be defined as a 'one-pole magnet'.

[0106] Referring to FIG. 8, the magnet (162) may include two pole areas (1624, 1625). The two pole areas (1624, 1625) may be arranged in parallel in the circumferential direction. The two pole areas (1624, 1625) may have different polarities. For example, the inner surface of the third pole area (1624) may have a north pole, and the inner surface of the fourth pole area (1625) may have a south pole.

[0107] The two polar regions (1624, 1625) can be formed in an overall arc shape. The two adjacent polar regions (1624, 1625) have an inner diameter (r-) of the two polar regions (1624, 1625). i ) may have different magnetic focal centers (b3, b4) from the center (O) of the third magnetic focal center. For example, the third magnetic focal center (b3) may have a third magnetic orientation (m) of the third pole region (1624). c ) may be the focus center, and the fourth magnetic focus center (b4) may be the fourth magnetic orientation (m) of the fourth pole region (1625). d) may be the focus center. The distance (r) between the magnetic focus centers (b3, b4) of the two polar regions (1624, 1625) and the two polar regions (1624, 1625) b ) may be identical to each other. The circumferential distances between the magnetic focal centers (b3, b4) of the two polar regions (1624, 1625) and the adjacent magnetic focal centers may be identical to each other.

[0108] In one embodiment of the present specification, a case where a magnet (162) is formed of two pole regions (1624, 1625) can be defined as a 'two-pole magnet'.

[0109] Referring to FIG. 9, the magnet (162) may include three pole regions (1626, 1627, 1628). The three pole regions (1626, 1627, 1628) may be arranged in parallel in the circumferential direction. The three pole regions (1626, 1627, 1628) may have different polarities. For example, the inner surface of the fifth pole region (1626) may have a north pole, the inner surface of the sixth pole region (1627) may have a south pole, and the inner surface of the seventh pole region (1628) may have a north pole.

[0110] The three pole regions (1626, 1627, 1628) can be formed in an overall arc shape. The adjacent three pole regions (1626, 1627, 1628) have an inner diameter (r-) of the three pole regions (1626, 1627, 1628). i ) may have different magnetic focal centers (b5, b6, b7) from the center (O) of the fifth magnetic focal center. For example, the fifth magnetic focal center (b5) may have a fifth magnetic orientation (m) of the fifth pole region (1626). e ) may be the focus center, and the sixth magnetic focus center (b6) may be the sixth magnetic orientation (m) of the sixth pole region (1627). f ) may be the focus center, and the seventh magnetic focus center (b7) may be the seventh magnetic orientation (m) of the seventh pole region (1628). g) may be the focus center. The distance (r) between the magnetic focus centers (b5, b6, b7) of the three polar regions (1626, 1627, 1628) and the three polar regions (1626, 1627, 1628) b ) can be identical to each other. The circumferential distances between the magnetic focal centers (b5, b6, b7) and the adjacent magnetic focal centers of the three polar regions (1626, 1627, 1628) can be identical to each other.

[0111] In one embodiment of the present specification, a case where a magnet (162) is formed of three pole regions (1626, 1627, 1628) may be defined as a 'three-pole magnet'.

[0112] Referring to FIGS. 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 in parallel in the circumferential direction. The four pole regions (1629, 1630, 1631, 1632) may have different polarities. For example, the inner surface of the eighth pole region (1629) may have a N pole, the inner surface of the ninth pole region (1630) may have a S pole, the inner surface of the tenth pole region (1631) may have a N pole, and the inner surface of the eleventh pole region (1632) may have a S pole. The four polar regions (1629, 1630, 1631, 1632) can be formed into an overall arc shape.

[0113] The four adjacent polar regions (1629, 1630, 1631, 1632) are the inner diameters (r-) of the four polar regions (1629, 1630, 1631, 1632). i ) may have different magnetic focal centers (b8, b9, b10, b11) from the center (O). For example, the eighth magnetic focal center (b8) may have the eighth magnetic orientation (m) of the eighth polar region (1629). h) may be the focus center, and the ninth magnetic focus center (b9) may be the ninth magnetic orientation (m) of the ninth pole region (1630). i ) may be the focus center, and the 10th magnetic focus center (b10) may be the 10th magnetic orientation (m) of the 10th pole region (1631). j ) may be the focus center, and the 11th magnetic focus center (b11) may be the 11th magnetic orientation (m) of the 11th pole region (1632). k ) may be the center of focus.

[0114] In this case, the distance (r) between the magnetic focal centers (b8, b9, b10, b11) of the four polar regions (1629, 1630, 1631, 1632) and the four polar regions (1629, 1630, 1631, 1632) b ) can be identical to each other. The circumferential distances between the magnetic focal centers (b8, b9, b10, b11) of the four polar regions (1629, 1630, 1631, 1632) and the adjacent magnetic focal centers can be identical to each other.

[0115] In one embodiment of the present specification, a case where a magnet (162) is formed of four pole regions (1629, 1630, 1631, 1632) may be defined as a '4-pole magnet'.

[0116] In one embodiment of the present specification, when there is at least one pole region (1622, 1623), the number of the plurality of magnets spaced apart in the circumferential direction is 48. When there are at least two pole regions (1624, 1625), the number of the plurality of magnets spaced apart in the circumferential direction is 24. When there are at least three pole regions (1626, 1627, 1628), the number of the plurality of magnets spaced apart in the circumferential direction is 24. When there are at least four pole regions (1629, 1630, 1631, 1632), the number of the plurality of magnets spaced apart in the circumferential direction is 12. Through this, the space efficiency of the motor (150, 160) applied to the washing machine (10) can be improved.

[0117] In one embodiment of the present specification, at least one polar region (1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632) is described as having 1 to 4 as examples, but cases where there are 5 or more are not excluded.

[0118] FIG. 13 is a plan view of a polar region according to one embodiment of the present specification.

[0119] Referring to Fig. 13, the polar anisotropy coefficient (X) is explained.

[0120] d m means the distance from a straight line (L2) connecting both ends of the magnetic center line (m2) of at least one polar region (1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632) to the central region of the magnetic center line (m2) of at least one polar region (1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632).

[0121] d b 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) i) has a magnetic focus center such as the center (O) of at least one polar region (1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632), the distance from a straight line (L1) connecting both ends of the magnetic center line (m1) of at least one polar region (1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632) to the central region of the magnetic center line (m1).

[0122] In Fig. 13, d m and d b It is explained based on vertical lines that are spaced left and right, but this is only a diagram to help understanding, and in reality, d m and d b can be interpreted as meaning the length based on overlapping vertical lines.

[0123] Here, d b can satisfy mathematical expression 1.

[0124]

[0125] Here, r i is the inner radius, r, of at least one polar region (1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632). o may mean the outer radius of at least one polar region (1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632), and p may mean the number of poles of at least one polar region (1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632).

[0126] The polar anisotropy coefficient (X) is a coefficient that determines how close the magnetic focus center 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), and can satisfy the following mathematical expression 2.

[0127]

[0128] FIG. 14 is a graph showing the rate of increase in the counter electromotive force of a motor with respect to the polar anisotropy coefficient of a magnet according to one embodiment of the present specification.

[0129] Referring to Fig. 14, the rate of increase in counter electromotive force with respect to the polar anisotropy coefficient (X) of the magnet (162) can be known. As the polar anisotropy coefficient (X) of the magnet (162) increases, the rate of increase in counter electromotive force of the motor (150, 160) increases. Here, the rate of increase in counter electromotive force means the ratio of the counter electromotive force when the polar anisotropy coefficient (X) changes to the counter 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) gets to at least one polar region (1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632), the higher the polar anisotropy coefficient (X).

[0130] As the polar anisotropy coefficient (X) increases, the orientation curve (electron arrangement of a magnetic material) gathers at the center of the circumference of the polar region, weakening the rigidity of the circumferential ends of the polar region, which may cause cracks to occur in the magnet (162). That is, if the polar anisotropy coefficient (X) continues to increase, cracks may occur in the magnet (162).

[0131] Specifically, when the magnet (162) is a 1-pole magnet, a crack occurs in the magnet (162) when the polar anisotropy coefficient (X) reaches 7.5, when the magnet (162) is a 2-pole magnet, a crack occurs in the magnet (162) when the polar anisotropy coefficient (X) reaches 6, when the magnet (162) is a 3-pole magnet, a crack occurs in the magnet (162) when the polar anisotropy coefficient (X) reaches 4.5, and when the magnet (162) is a 4-pole magnet, a crack may occur in the magnet (162) when the polar anisotropy coefficient (X) reaches 3.5.

[0132] Therefore, it is preferable that the polar anisotropy coefficient (X) is less than 7.5 when at least one pole region (1622, 1623) of the magnet (162) is 1, the polar anisotropy coefficient (X) is less than 6 when at least one pole region (1624, 1625) is 2, the polar anisotropy coefficient (X) is less than 4.5 when at least one pole region (1626, 1627, 1628) is 3, and the polar anisotropy coefficient (X) is less than 3.5 when at least one pole region (1629, 1630, 1631, 1632) is 4.

[0133] Through this, the counter electromotive force of the motor (150, 160) can be increased while the possibility of cracks occurring in the magnet (162) can be reduced, thereby preventing damage to the product.

[0134] Fig. 15 is a graph showing the rate of change in the material cost of a stator with respect to the polar anisotropy coefficient of a magnet according to one embodiment of the present disclosure. Fig. 16 is a graph showing the rate of change in the rotor manufacturing cost with respect to the number of pole areas in one magnet according to one embodiment of the present disclosure. Fig. 17 is a graph showing the rate of change in the material cost of a motor with respect to the polar anisotropy coefficient of a magnet according to one embodiment of the present disclosure. Fig. 18 is a graph showing the rate of increase in the counter electromotive force of a motor with respect to the polar anisotropy coefficient of a magnet according to one embodiment of the present disclosure.

[0135] It was confirmed in Fig. 14 that as the polar anisotropy coefficient (X) increases, the counter electromotive force of the motor (150, 160) increases. In general, as the stacking height of the stator core in the core of the same rotor (160) decreases, the counter electromotive force of the motor decreases.

[0136] When the polar anisotropy coefficient (X) is increased to 1 or more, the counter electromotive force can be made equivalent to that when the polar anisotropy coefficient (X) is 1 by reducing the stacking height of the stator core. In other words, when the polar anisotropy coefficient (X) is set to 1 or more, there is an effect of reducing the material cost of the stator by reducing the stacking height of the stator core.

[0137] Referring to FIG. 15, the change rate of the material cost of the stator of the motor (150, 160) according to the polar anisotropy coefficient (X) of the motor (150, 160) can be known. As the polar anisotropy coefficient (X) increases, the counter electromotive force of the motor (150, 160) increases, and since the lamination of the stator of the motor (150, 160) can be reduced, the material cost of the stator can be reduced. Here, the material cost ratio of the stator means 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 set to 1.

[0138] Referring to FIG. 16, the ratio of the manufacturing cost of the rotor (160) to the number of pole areas (1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632) in one magnet can be known. Here, the ratio of the manufacturing cost of the rotor (160) means the manufacturing cost of the rotor when the number of pole areas in one magnet (162) is less than 6 compared to the manufacturing cost of the rotor (160) when one magnet (162) is composed of 6 pole areas.

[0139] Even if the number of pole areas (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 magnet (162) in the rotor (160) does not change significantly.

[0140] However, as the number of polar regions (1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632) in one magnet (162) increases, the number of physical magnets (162) in the rotor (160) decreases. For example, when one magnet (162) has one pole area (1622, 1623), 48 physical magnets (162) of the rotor (160) are required, when one magnet (162) has two pole areas (1624, 1625), 24 physical magnets (162) of the rotor (160) are required, when one magnet (162) has three pole areas (1626, 1627, 1628), 16 physical magnets (162) of the rotor (160) are required, when one magnet (162) has four pole areas (1629, 1630, 1631, 1632), 12 physical magnets (162) of the rotor (160) are required, and If the magnet (162) has six pole areas, eight physical magnets (162) of the rotor (160) are required.

[0141] As the number of physical magnets (162) of the rotor (160) increases, the number of work tasks required to attach the magnets (162) to the inside of the rotor core (164) increases, which in turn increases the work costs. In other words, as the number of pole areas (1622, 1623, 1624, 1625, 1626, 1627, 1628, 1629, 1630, 1631, 1632) of one magnet (162) decreases, the manufacturing cost of the rotor (160) can be seen to increase.

[0142] Referring to Fig. 17, the material cost ratio of the motor (150, 160) to the polar anisotropy coefficient (X) of the magnet (162) can be known. The material cost of the motor (150, 160) can be understood to include the material cost of the stator described in Fig. 15 and the manufacturing cost of the rotor (160) described in Fig. 16.

[0143] In Fig. 17, based on 100% of the material cost of the motor (150, 160), it can be seen that when one magnet (162) has one pole area (1622, 1623), the polar anisotropy coefficient (X) is 6, when there are two pole areas (1624, 1625), the polar anisotropy coefficient (X) is 4.5, when there are three pole areas (1626, 1627, 1628), the polar anisotropy coefficient (X) is 3.5, and when there are four pole areas (1629, 1630, 1631, 1632), the polar anisotropy coefficient (X) is 2.5.

[0144] It can be seen that the material cost of the motor (150, 160) is reduced to less than 100% when the polar anisotropy coefficient (X) exceeds 6 when at least one polar region (1622, 1623) is 1, when at least one polar region (1624, 1625) is 2, when the polar anisotropy coefficient (X) exceeds 4.5, when at least one polar region (1626, 1627, 1628) is 3, when the polar anisotropy coefficient (X) exceeds 3.5, and when at least one polar region (1629, 1630, 1631, 1632) is 4, when the polar anisotropy coefficient (X) exceeds 2.5. This means the lowest threshold for setting the polar anisotropy coefficient (X) within the limited material cost of the motor (150, 160).

[0145] Therefore, referring to FIG. 18, considering the material cost of the limited motor (150, 160) without cracking in the magnet (162), the most optimal polar anisotropy coefficient (X) is to be designed such that the polar anisotropy coefficient (X) is between 6 and 7.5 when at least one pole region (1622, 1623) is 1, the polar anisotropy coefficient (X) is between 4.5 and 6 when at least one pole region (1624, 1625) is 2, the polar anisotropy coefficient (X) is between 3.5 and 4.5 when at least one pole region (1626, 1627, 1628) is 3, and the polar anisotropy coefficient (X) is between 2.5 and 3.5 when at least one pole region (1629, 1630, 1631, 1632) is 4. This can be said to be the orientation of the magnet (162).

[0146] Figures 19 to 21 are plan views of a magnet according to one embodiment of the present specification.

[0147] Referring to FIGS. 19 to 21, a magnet (162) according to one embodiment of the present specification may include a plurality of pole areas (1624, 1625). The magnet (162) may be formed in an arc shape. The plurality of pole areas (1624, 1625) may be arranged in parallel in a circumferential direction.

[0148] A chamfer (165) may be formed on the inner surface of both ends of the polar region (1624, 1625). Through this, the cogging torque of the motor (150, 160) can be reduced and the counter electromotive force of the motor (150, 160) can be improved. Here, the cogging torque refers to a force that prevents the rotation of the rotor (160) when the rotor (160) is about to rotate, and may be generated by a force acting between the magnet (162) of the rotor (160) and the stator of the stator (150).

[0149] With reference to FIG. 19, the chamfer (165) of the third pole region (1624) may include an outer chamfer (1651) positioned on the left and an inner chamfer (1652) positioned on the right, and the chamfer (165) of the fourth pole region (1625) may include an inner chamfer (1653) positioned on the left and an outer chamfer (1654) positioned on the right. The inner chamfer (1652) of the third pole region (1624) and the inner chamfer (1653) of the fourth pole region (1625) may be connected to each other. The inner chamfer (1652) of the third pole region (1624) and the inner chamfer (1653) of the fourth pole region (1625) may be formed in a shape that is symmetrical to each other. The outer chamfer (1651) of the third pole region (1624) and the outer chamfer (1654) of the fourth pole region (1625) can be formed in a shape that is symmetrical to each other.

[0150] In FIG. 19, the case where there are two polar regions (1624, 1625) and two chamfers (165) for each polar region (1624, 1625) is described as an example, but as in FIGS. 20 and 21, there may be four polar regions (1629, 1630, 1631, 1632) and there may be two chamfers (165) for each polar region (1629, 1630, 1631, 1632), or the number of polar regions may be three or five or more.

[0151] In addition, as shown in Fig. 20, the cross-section of the chamfer (165) may be formed in a straight line shape, or as shown in Fig. 21, the cross-section of the chamfer (165) may be formed in a curved shape. In Fig. 21, the cross-section of the chamfer (165) is shown as a curved shape that is concave outward in the radial direction, but may also be a curved shape that is convex inward in the radial direction.

[0152] Here, radially outer may be interpreted as meaning an upward direction based on FIGS. 19 to 21, radially inner may be interpreted as meaning a downward direction based on FIGS. 19 to 21, and circumferential may be interpreted as meaning a left or right direction.

[0153] FIG. 22 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the radial length of the outer chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0154] Referring to FIG. 22, the average rate of change in the counter electromotive force of the motor (150, 160) according to the percentage obtained by dividing the radial length (d2) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625) can be known. That is, it can be seen that the counter electromotive force of the motor (150, 160) decreases as the radial length (d2) of the outer chamfer (1651, 1654) increases.

[0155] Here, the rate of change in counter electromotive force can be interpreted as meaning the counter electromotive force of the motor (150, 160) when there is a chamfer (165) in the magnet (162) compared to the counter electromotive force of the motor (150, 160) when there is no chamfer (165) in the magnet (162).

[0156] FIG. 23 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the radial length of the outer chamfer of the pole area of ​​a magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0157] Referring to FIG. 23, the average rate of change in cogging torque of the motor (150, 160) can be determined according to the percentage obtained by dividing the radial length (d2) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625). That is, as the radial length (d2) of the outer chamfer (1651, 1654) increases, the cogging torque of the motor (150, 160) decreases, and when the value obtained by dividing the radial length (d2) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625) is 0.2083, the cogging torque of the motor (150, 160) is minimized, and when the radial length (d2) of the outer chamfer (1651, 1654) increases further, the cogging torque of the motor (150, 160) increases again.

[0158] Here, the cogging torque change rate can be interpreted as meaning the cogging torque of the motor (150, 160) when the magnet (162) has a chamfer (165) compared to the cogging torque of the motor (150, 160) when the magnet (162) does not have a chamfer (165).

[0159] FIG. 24 is a graph showing the average of the weights of the motor according to the percentage of the radial length of the outer chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0160] Referring to FIG. 24, the average of the weights of the motors (150, 160) according to the percentage obtained by dividing the radial length (d2) of the outer chamfers (1651, 1654) of the pole areas (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole areas (1624, 1625) can be known. Here, the weight of the motors (150, 160) means a value obtained by dividing the rate of change in the counter electromotive force of the motors (150, 160) by the rate of change in the cogging torque of the motors (150, 160).

[0161] That is, as the radial length (d2) of the outer chamfer (1651, 1654) increases, the weight of the motor (150, 160) increases. When the value obtained by dividing the radial length (d2) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625) is 0.2083, the weight of the motor (150, 160) becomes maximum. When the radial length (d2) of the outer chamfer (1651, 1654) increases further, it can be seen that the weight of the motor (150, 160) decreases again.

[0162] FIG. 25 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the circumferential length of the outer chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0163] Referring to FIG. 25, the average rate of change in the counter electromotive force of the motor (150, 160) according to the percentage obtained by dividing the circumferential length (A1) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625) can be known. That is, it can be seen that as the circumferential length (A1) of the outer chamfer (1651, 1654) increases, the counter electromotive force of the motor (150, 160) decreases.

[0164] FIG. 26 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the circumferential length of the outer chamfer of the pole area of ​​a magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0165] Referring to FIG. 26, the average cogging torque change rate of the motor (150, 160) can be determined according to the percentage obtained by dividing the circumferential length (A1) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625). That is, as the circumferential length (A1) of the outer chamfer (1651, 1654) increases, the cogging torque of the motor (150, 160) decreases, and when the value obtained by dividing the circumferential length (A1) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625) is 0.1933, the cogging torque of the motor (150, 160) is minimized, and when the circumferential length (A1) of the outer chamfer (1651, 1654) increases further, the cogging torque of the motor (150, 160) increases again.

[0166] FIG. 27 is a graph showing the average of the weights of the motor according to the percentage of the circumferential length of the outer chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0167] Referring to FIG. 27, the average of the weights of the motors (150, 160) can be determined based on the percentage of the circumferential length (A1) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) divided by the circumferential length (At) of the pole area (1624, 1625).

[0168] That is, as the circumferential length (A1) of the outer chamfer (1651, 1654) increases, the weight of the motor (150, 160) increases. When the value obtained by dividing the circumferential length (A1) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625) is 0.1933, the weight of the motor (150, 160) becomes maximum, and when the circumferential length (A1) of the outer chamfer (1651, 1654) increases further, it can be seen that the weight of the motor (150, 160) decreases again.

[0169] FIG. 28 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the radial length of the inner chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0170] Referring to FIG. 28, the average rate of change in the counter electromotive force of the motor (150, 160) according to the percentage obtained by dividing the radial length (d1) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625) can be known. That is, it can be seen that the counter electromotive force of the motor (150, 160) decreases as the radial length (d1) of the inner chamfer (1652, 1653) increases.

[0171] FIG. 29 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the radial length of the inner chamfer of the pole area of ​​a magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0172] Referring to FIG. 29, the average rate of change in cogging torque of the motor (150, 160) can be determined according to the percentage obtained by dividing the radial length (d1) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625). That is, as the radial length (d1) of the inner chamfer (1652, 1653) increases, the cogging torque of the motor (150, 160) decreases, and when the value obtained by dividing the radial length (d1) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625) is 0.2083, the cogging torque of the motor (150, 160) is minimized, and when the radial length (d1) of the inner chamfer (1652, 1653) increases further, the cogging torque of the motor (150, 160) increases again.

[0173] FIG. 30 is a graph showing the average of the weights of the motor according to the percentage of the radial length of the inner chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0174] Referring to FIG. 30, the average of the weights of the motors (150, 160) can be determined based on the percentage of the radial length (d1) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) divided by the radial length (Mt) of the pole area (1624, 1625).

[0175] That is, as the radial length (d1) of the inner chamfer (1652, 1653) increases, the weight of the motor (150, 160) increases. When the value obtained by dividing the radial length (d1) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625) is 0.2083, the weight of the motor (150, 160) becomes maximum, and when the radial length (d1) of the inner chamfer (1652, 1653) increases further, it can be seen that the weight of the motor (150, 160) decreases again.

[0176] FIG. 31 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the circumferential length of the inner chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0177] Referring to FIG. 31, the average rate of change in the counter electromotive force of the motor (150, 160) according to the percentage obtained by dividing the circumferential length (A2) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625) can be known. That is, it can be seen that as the circumferential length (A2) of the inner chamfer (1652, 1653) increases, the counter electromotive force of the motor (150, 160) decreases.

[0178] FIG. 32 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the circumferential length of the inner chamfer of the pole area of ​​a magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0179] Referring to FIG. 32, the average cogging torque change rate of the motor (150, 160) can be determined according to the percentage obtained by dividing the circumferential length (A2) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625). That is, as the circumferential length (A2) of the inner chamfer (1652, 1653) increases, the cogging torque of the motor (150, 160) decreases, and when the value obtained by dividing the circumferential length (A2) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625) is 0.1933, the cogging torque of the motor (150, 160) is minimized, and when the circumferential length (A2) of the inner chamfer (1652, 1653) increases further, the cogging torque of the motor (150, 160) increases again.

[0180] FIG. 33 is a graph showing the average of the weights of the motor according to the percentage of the circumferential length of the inner chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0181] Referring to FIG. 33, the average of the weights of the motors (150, 160) can be determined based on the percentage of the circumferential length (A2) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) divided by the circumferential length (At) of the pole area (1624, 1625).

[0182] That is, as the circumferential length (A2) of the inner chamfer (1652, 1653) increases, the weight of the motor (150, 160) increases. When the value obtained by dividing the circumferential length (A2) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625) is 0.1933, the weight of the motor (150, 160) becomes maximum. When the circumferential length (A1) of the inner chamfer (1652, 1653) increases further, it can be seen that the weight of the motor (150, 160) decreases again.

[0183] Referring to FIGS. 22 to 33, it can be confirmed that the weight of the motor (150, 160) according to the change in the radial length (d2) of the outer chamfer (1651, 1654) as a whole corresponds to the weight of the motor (150, 160) according to the change in the radial length (d1) of the inner chamfer (1652, 1653), and the weight of the motor (150, 160) according to the change in the circumferential length (A1) of the outer chamfer (1651, 1654) corresponds to the weight of the motor (150, 160) according to the change in the circumferential length (A2) of the inner chamfer (1652, 1653), so that the inner chamfer (1652, 1653) and the outer chamfer (1651, 1654) do not need to be separately distinguished.

[0184] That is, the value obtained by dividing the radial length (d1, d2) of the chamfer (165) by the radial length (Mt) of the polar regions (1624, 1625) may be between 0.20 and 0.21. Preferably, the value obtained by dividing the radial length (d1, d2) of the chamfer (165) by the radial length (Mt) of the polar regions (1624, 1625) may be between 0.208 and 0.209. More preferably, the value obtained by dividing the radial length (d1, d2) of the chamfer (165) by the radial length (Mt) of the polar regions (1624, 1625) may be 0.2083.

[0185] Additionally, the value obtained by dividing the circumferential length (A1, A2) of the chamfer (165) by the circumferential length (At) of the polar regions (1624, 1625) may be between 0.19 and 0.20. Preferably, the value obtained by dividing the circumferential length (A1, A2) of the chamfer (165) by the circumferential length (At) of the polar regions (1624, 1625) may be between 0.193 and 0.194. More preferably, the value obtained by dividing the circumferential length (A1, A2) of the chamfer (165) by the circumferential length (At) of the polar regions (1624, 1625) may be 0.1933.

[0186] Through this, the efficiency of the counter electromotive force of the motor (150, 160) can be improved compared to the cogging torque of the motor (150, 160).

[0187] In FIGS. 22 to 33, the case where the number of multiple polar regions (1624, 1625) is two is described, but this can also be applied to a case where the number of multiple polar regions (1624, 1625) is three or more.

[0188] In FIGS. 22 to 33, a plurality of polar regions (1624, 1625) are formed with an inner diameter (r) of the plurality of polar regions (1624, 1625). i ) has the same magnetic focus center as the center (O), that is, the case where the magnetic focus center of the magnet (162) is not polar anisotropic.

[0189] Below, in FIGS. 34 to 45, a plurality of polar regions (1624, 1625) are formed by the inner diameter (r) of the plurality of polar regions (1624, 1625). i ) does not have a magnetic focus center such as the center (O) of the magnet (162), that is, the magnetic focus center of the magnet (162) is anisotropic. In other words, the case where each of the plurality of polar regions (1624, 1625) has a separate magnetic focus center (b3, b4) is described.

[0190] FIG. 34 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the radial length of the outer chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0191] Referring to FIG. 34, the average rate of change in the counter electromotive force of the motor (150, 160) according to the percentage obtained by dividing the radial length (d2) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625) can be known. That is, it can be seen that the counter electromotive force of the motor (150, 160) decreases as the radial length (d2) of the outer chamfer (1651, 1654) increases.

[0192] FIG. 35 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the radial length of the outer chamfer of the pole area of ​​a magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0193] Referring to FIG. 35, the average rate of change in cogging torque of the motor (150, 160) can be determined according to the percentage obtained by dividing the radial length (d2) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625). That is, as the radial length (d2) of the outer chamfer (1651, 1654) increases, the cogging torque of the motor (150, 160) decreases, and when the value obtained by dividing the radial length (d2) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625) is 0.1667, the cogging torque of the motor (150, 160) is minimized, and when the radial length (d2) of the outer chamfer (1651, 1654) increases further, the cogging torque of the motor (150, 160) increases again.

[0194] FIG. 36 is a graph showing the average of the weights of the motor according to the percentage of the radial length of the outer chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0195] Referring to FIG. 36, the average of the weights of the motors (150, 160) can be determined based on the percentage of the radial length (d2) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) divided by the radial length (Mt) of the pole area (1624, 1625).

[0196] That is, as the radial length (d2) of the outer chamfer (1651, 1654) increases, the weight of the motor (150, 160) increases. When the value obtained by dividing the radial length (d2) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625) is 0.1667, the weight of the motor (150, 160) becomes maximum. When the radial length (d2) of the outer chamfer (1651, 1654) increases further, it can be seen that the weight of the motor (150, 160) decreases again.

[0197] FIG. 37 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the circumferential length of the outer chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0198] Referring to FIG. 37, the average rate of change in the counter electromotive force of the motor (150, 160) according to the percentage obtained by dividing the circumferential length (A1) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625) can be known. That is, it can be seen that as the circumferential length (A1) of the outer chamfer (1651, 1654) increases, the counter electromotive force of the motor (150, 160) decreases.

[0199] FIG. 38 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the circumferential length of the outer chamfer of the pole area of ​​a magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0200] Referring to FIG. 38, the average cogging torque change rate of the motor (150, 160) can be determined according to the percentage obtained by dividing the circumferential length (A1) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625). That is, as the circumferential length (A1) of the outer chamfer (1651, 1654) increases, the cogging torque of the motor (150, 160) decreases, and when the value obtained by dividing the circumferential length (A1) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625) is 0.16, the cogging torque of the motor (150, 160) is minimized, and when the circumferential length (A1) of the outer chamfer (1651, 1654) increases further, the cogging torque of the motor (150, 160) increases again.

[0201] FIG. 39 is a graph showing the average of the weights of the motor according to the percentage of the circumferential length of the outer chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0202] The average weight of the motor (150, 160) can be determined by dividing the circumferential length (A1) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625).

[0203] That is, as the circumferential length (A1) of the outer chamfer (1651, 1654) increases, the weight of the motor (150, 160) increases. When the value obtained by dividing the circumferential length (A1) of the outer chamfer (1651, 1654) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625) is 0.16, the weight of the motor (150, 160) becomes maximum, and when the circumferential length (A1) of the outer chamfer (1651, 1654) increases further, it can be seen that the weight of the motor (150, 160) decreases again.

[0204] FIG. 40 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the radial length of the inner chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0205] Referring to FIG. 40, the average rate of change in the counter electromotive force of the motor (150, 160) according to the percentage obtained by dividing the radial length (d1) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625) can be known. That is, it can be seen that the counter electromotive force of the motor (150, 160) decreases as the radial length (d1) of the inner chamfer (1652, 1653) increases.

[0206] FIG. 41 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the radial length of the inner chamfer of the pole area of ​​a magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0207] Referring to FIG. 41, the average rate of change in cogging torque of the motor (150, 160) can be determined according to the percentage obtained by dividing the radial length (d1) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625). That is, as the radial length (d1) of the inner chamfer (1652, 1653) increases, the cogging torque of the motor (150, 160) decreases, and when the value obtained by dividing the radial length (d1) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625) is 0.1667, the cogging torque of the motor (150, 160) is minimized, and when the radial length (d1) of the inner chamfer (1652, 1653) increases further, the cogging torque of the motor (150, 160) increases again.

[0208] FIG. 42 is a graph showing the average of the weights of the motor according to the percentage of the radial length of the inner chamfer of the pole area of ​​the magnet divided by the radial length of the pole area according to one embodiment of the present specification.

[0209] Referring to FIG. 42, the average of the weights of the motors (150, 160) can be determined based on the percentage of the radial length (d1) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) divided by the radial length (Mt) of the pole area (1624, 1625).

[0210] That is, as the radial length (d1) of the inner chamfer (1652, 1653) increases, the weight of the motor (150, 160) increases. When the value obtained by dividing the radial length (d1) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the radial length (Mt) of the pole area (1624, 1625) is 0.1667, the weight of the motor (150, 160) becomes maximum. When the radial length (d1) of the inner chamfer (1652, 1653) increases further, it can be seen that the weight of the motor (150, 160) decreases again.

[0211] FIG. 43 is a graph showing the average rate of change in the counter electromotive force of the motor according to the percentage of the circumferential length of the inner chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0212] Referring to FIG. 43, the average rate of change in the counter electromotive force of the motor (150, 160) according to the percentage obtained by dividing the circumferential length (A2) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625) can be known. That is, it can be seen that the larger the circumferential length (A2) of the inner chamfer (1652, 1653), the smaller the counter electromotive force of the motor (150, 160).

[0213] FIG. 44 is a graph showing the average rate of change in cogging torque of a motor according to the percentage of the circumferential length of the inner chamfer of the pole area of ​​a magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0214] Referring to FIG. 44, the average cogging torque change rate of the motor (150, 160) can be determined according to the percentage obtained by dividing the circumferential length (A2) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625). That is, as the circumferential length (A2) of the inner chamfer (1652, 1653) increases, the cogging torque of the motor (150, 160) decreases, and when the value obtained by dividing the circumferential length (A2) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625) is 0.16, the cogging torque of the motor (150, 160) is minimized, and when the circumferential length (A2) of the inner chamfer (1652, 1653) increases further, the cogging torque of the motor (150, 160) increases again.

[0215] FIG. 45 is a graph showing the average of the weights of the motor according to the percentage of the circumferential length of the inner chamfer of the pole area of ​​the magnet divided by the circumferential length of the pole area according to one embodiment of the present specification.

[0216] Referring to FIG. 5, the average of the weights of the motors (150, 160) can be determined based on the percentage of the circumferential length (A2) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) divided by the circumferential length (At) of the pole area (1624, 1625).

[0217] That is, as the circumferential length (A2) of the inner chamfer (1652, 1653) increases, the weight of the motor (150, 160) increases. When the value obtained by dividing the circumferential length (A2) of the inner chamfer (1652, 1653) of the pole area (1624, 1625) of the magnet (162) by the circumferential length (At) of the pole area (1624, 1625) is 0.16, the weight of the motor (150, 160) becomes maximum, and when the circumferential length (A1) of the inner chamfer (1652, 1653) increases further, the weight of the motor (150, 160) decreases again.

[0218] Referring to FIGS. 34 to 45, a plurality of polar regions (1624, 1625) are formed with an inner diameter (r) of the plurality of polar regions (1624, 1625). i ) has a center (O) of the outer chamfer (1651, 1654) and different magnetic focus centers (b3, b4), the weight of the motor (150, 160) according to the change in the radial length (d2) of the outer chamfer (1651, 1654) as a whole corresponds to the weight of the motor (150, 160) according to the change in the radial length (d1) of the inner chamfer (1652, 1653), and the weight of the motor (150, 160) according to the change in the circumferential length (A1) of the outer chamfer (1651, 1654) corresponds to the weight of the motor (150, 160) according to the change in the circumferential length (A2) of the inner chamfer (1652, 1653), so that the inner chamfer (1652, 1653) and the outer chamfer (1651, 1654) do not need to be distinguished separately. You can check it.

[0219] That is, the value obtained by dividing the radial length (d1, d2) of the chamfer (165) by the radial length (Mt) of the polar regions (1624, 1625) may be between 0.16 and 0.17. Preferably, the value obtained by dividing the radial length (d1, d2) of the chamfer (165) by the radial length (Mt) of the polar regions (1624, 1625) may be between 0.166 and 0.167. More preferably, the value obtained by dividing the radial length (d1, d2) of the chamfer (165) by the radial length (Mt) of the polar regions (1624, 1625) may be 0.1667.

[0220] Additionally, the value obtained by dividing the circumferential length (A1, A2) of the chamfer (165) by the circumferential length (At) of the polar regions (1624, 1625) may be between 0.155 and 0.165. Preferably, the value obtained by dividing the circumferential length (A1, A2) of the chamfer (165) by the circumferential length (At) of the polar regions (1624, 1625) may be between 0.1595 and 0.1605. More preferably, the value obtained by dividing the circumferential length (A1, A2) of the chamfer (165) by the circumferential length (At) of the polar regions (1624, 1625) may be 0.16.

[0221] Through this, the cogging torque of the motor (150, 160)

[0222] The counter electromotive force efficiency of the contrast motor (150, 160) can be improved.

[0223] Referring to FIGS. 22 to 45, it can be seen that when the magnetic focus center of the magnet (162) is polarized, the same efficiency is exhibited even when the radial length (d1, d2) and the circumferential length (A1, A2) of the chamfer (165) are smaller than when the magnetic focus center is not polarized.

[0224] That is, when there is a chamfer (165) in the magnet (162), it can be seen that the efficiency of the counter electromotive force of the motor (150, 160) relative to the cogging torque of the motor (150, 160) increases as the polar anisotropy coefficient (X) increases. However, in order to prevent damage to the magnet (162), when there are two pole regions (1624, 1625), it is preferable that the polar anisotropy coefficient (X) is less than 6, when there are three pole regions (1626, 1627, 1628), it is preferable that the polar anisotropy coefficient (X) is less than 4.5, and when there are four pole regions (1629, 1630, 1631), it is preferable that the polar anisotropy coefficient (X) is less than 3.5.

[0225] In FIGS. 34 to 45, the case where the number of multiple polar regions (1624, 1625) is two is described, but this can also be applied when the number of multiple polar regions (1624, 1625) is three or more.

[0226] Fig. 46 is a graph showing the counter electromotive force of a motor according to a conventional method and an embodiment of the present specification.

[0227] Referring to FIG. 46, it can be seen that the counter electromotive force of the motor (150, 160) having a magnet (162) according to one embodiment of the present specification is substantially the same at 98.9% compared to the base without a chamfer.

[0228] Fig. 47 is a graph showing the cogging torque of a motor according to a conventional method and an embodiment of the present specification.

[0229] Referring to FIG. 47, it can be seen that the cogging torque of the motor (150, 160) is significantly reduced by 23% for the motor (optimized) having the magnet (162) according to one embodiment of the present disclosure compared to the base without the chamfer.

[0230] Any or all of the embodiments of this specification described above are not mutually exclusive or distinct. Any or all of the embodiments of this specification described above may have their respective components or functions combined or used together.

[0231] For example, it means that a configuration A described in a particular embodiment and / or drawing can be combined with a configuration B described in another embodiment and / or drawing. That is, even if a combination between configurations is not directly described, it means that a combination is possible, except in cases where a combination is described as impossible.

[0232] The above detailed description should not be construed as limiting in any respect and should be considered illustrative only. The scope of this specification should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of this specification are intended to be embraced therein.

Claims

1. It comprises a plurality of polar regions formed in an arc shape and arranged in a parallel direction in the circumferential direction, A chamfer is formed on the inner surface of both ends of the above polar region, A magnet in which the radial length of the above chamfer divided by the radial length of the above polar region is between 0.20 and 0.

21.

2. In paragraph 1, A magnet in which the radial length of the above chamfer divided by the radial length of the above polar region is between 0.208 and 0.

209.

3. In paragraph 1, A magnet in which the circumferential length of the above chamfer divided by the circumferential length of the above polar region is between 0.19 and 0.

20.

4. In paragraph 3, A magnet in which the circumferential length of the above chamfer divided by the circumferential length of the above polar region is between 0.193 and 0.

194.

5. In paragraph 1, The cross section of the above chamfer is formed as a straight or curved magnet.

6. It comprises a plurality of polar regions formed in an arc shape and arranged in a parallel direction in the circumferential direction, A chamfer is formed on the inner surface of both ends of the above polar region, A magnet in which the circumferential length of the above chamfer divided by the circumferential length of the above polar region is between 0.19 and 0.

20.

7. In paragraph 6, A magnet in which the circumferential length of the above chamfer divided by the circumferential length of the above polar region is between 0.193 and 0.

194.

8. In paragraph 6, The cross section of the above chamfer is formed as a straight or curved magnet.

9. It comprises a plurality of polar regions formed in an arc shape and arranged in a parallel direction in the circumferential direction, The above plurality of polar regions have their respective magnetic focus centers different from the centers of the inner diameters of the above plurality of polar regions, A chamfer is formed on the inner surface of both ends of the above polar region, A magnet in which the radial length of the above chamfer divided by the radial length of the above pole area is between 0.16 and 0.

17.

10. In paragraph 9, A magnet in which the radial length of the above chamfer divided by the radial length of the above polar region is between 0.166 and 0.

167.

11. In paragraph 9, A magnet in which the circumferential length of the above chamfer divided by the circumferential length of the above polar region is between 0.155 and 0.

165.

12. In paragraph 11, A magnet in which the circumferential length of the above chamfer divided by the circumferential length of the above polar region is between 0.1595 and 0.1605.

13. In paragraph 9, The cross section of the above chamfer is formed as a straight or curved magnet.

14. In paragraph 9, The above multiple polar regions are given by the following formula: and satisfy, (Here, d m is the distance from the straight line connecting the two ends of the magnetic center lines of the above plurality of polar regions to the central region of the magnetic center lines of the above plurality of polar regions, and d b is the distance from the straight line connecting both ends of the magnetic center lines of the plurality of polar regions to the central region of the magnetic center lines of the plurality of polar regions when the plurality of polar regions have a magnetic focus center that is the same as the center of the inner diameter of the plurality of polar regions), If the above multiple polar regions are two, X<6, If the above multiple polar regions are three, then X<4.5, A magnet that satisfies X<3.5 when the above multiple polar areas are four.

15. It comprises a plurality of polar regions formed in an arc shape and arranged in a parallel direction in the circumferential direction, The above plurality of polar regions have their respective magnetic focus centers different from the centers of the inner diameters of the above plurality of polar regions, A chamfer is formed on the inner surface of both ends of the above polar region, A magnet in which the circumferential length of the above chamfer divided by the circumferential length of the above polar region is between 0.155 and 0.

165.

16. In paragraph 15, A magnet in which the circumferential length of the above chamfer divided by the circumferential length of the above polar region is between 0.1595 and 0.1605.

17. In paragraph 15, The cross section of the above chamfer is formed as a straight or curved magnet.

18. In paragraph 15, The above multiple polar regions are given by the following formula: and satisfy, (Here, d m is the distance from the straight line connecting the two ends of the magnetic center lines of the above plurality of polar regions to the central region of the magnetic center lines of the above plurality of polar regions, and d b is the distance from the straight line connecting both ends of the magnetic center lines of the plurality of polar regions to the central region of the magnetic center lines of the plurality of polar regions when the plurality of polar regions have a magnetic focus center that is the same as the center of the inner diameter of the plurality of polar regions), If the above multiple polar regions are two, X<6, If the above multiple polar regions are three, then X<4.5, A magnet that satisfies X<3.5 when the above multiple polar areas are four.

19. Stator; and The rotor comprises a rotor core arranged radially outside the stator, and a rotor including a plurality of magnets arranged on the inner surface of the rotor core and facing the stator, A motor wherein the magnet is a magnet according to any one of claims 1 to 18.

20. A washing machine comprising a motor according to Article 19.

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