Rotor, motor, and auxiliary rotor

Abstract

The present disclosure aims to provide a rotor, motor, and auxiliary rotor that can increase the number of magnets by utilizing the space formed inside the stator coil end, while increasing the utilization efficiency of the increased magnets and preventing a decrease in cost efficiency. [Solution] In the rotor 5 according to this disclosure, each first magnet 22 of the first rotor end 20 and each second magnet 32 ​​of the second rotor end 30 are arranged in a Halbach arrangement along the circumference C, and a single first magnet 22 and a second magnet 32 ​​arranged in a line along the central axis L and the main magnet 12 of the rotor main part 10 are arranged in a Halbach arrangement, and the first rotor end 20 and the second rotor end 30 do not face the stator core 45.

Description

Technical Field

[0001] The present disclosure relates to a rotor, a motor, and an auxiliary rotor.

Background Art

[0002] Conventionally, in order to drive a motor with high torque, a motor is known in which a main magnet element and an auxiliary magnet element are arranged in a Halbach array in the rotational axis direction of a rotor (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional rotor, since each magnet is arranged in a Halbach array, high torque can be obtained. However, in a motor, it is required to further improve to obtain a higher output. On the other hand, there is a space inside the stator coil end of the motor. Researchers considered further increasing the output of the motor by effectively utilizing this space. As a result, it was considered to obtain a high output by extending the magnets of the rotor even into the space formed inside the stator coil end and using magnets longer than the length of the stator core in the rotational axis direction for the rotor.

[0005] In this configuration, the extended magnets increased the magnetic flux, and this increased flux flowed into the stator core. However, since the extended portion of the magnets did not face the stator, the magnetic flux generated by the extended magnets was directed towards the ends of the stator. It was found that the magnetic flux flow in this section resulted in greater magnetic flux resistance compared to the magnetic flux flow when the stator and rotor were positioned facing each other.

[0006] In other words, it was discovered that an increase in magnetic flux proportional to the extension of the magnet could not be expected. Consequently, the utilization efficiency of the magnet decreases, leading to a problem of reduced cost efficiency.

[0007] This disclosure aims to provide a rotor, motor, and auxiliary rotor that can increase the number of magnets by utilizing the space formed inside the stator coil end, while increasing the utilization efficiency of the increased magnets and preventing a decrease in cost efficiency, in order to solve the above problems. [Means for solving the problem]

[0008] The rotor according to this disclosure comprises a rotor main portion that rotates about a central axis, a first rotor end positioned at one end of the rotor main portion in the direction along the central axis, and a second rotor end positioned at the other end of the rotor main portion opposite to the one end in the direction along the central axis, wherein the rotor main portion has a plurality of main magnets, the first rotor end has a plurality of first magnets, and the second rotor end has a plurality of second magnets, and when viewed along the central axis, each of the main magnets, each of the first magnets, and each of the second magnets are arranged in a line along the circumference of a circle having its center on the central axis, and each of the first magnets and each of the second magnets are arranged in a Halbach configuration along the corresponding circumference The magnets are arranged in rows, and when viewed from a direction perpendicular to the central axis, each main magnet, its corresponding first magnet, and its corresponding second magnet are arranged in a line along the central axis. Of the first magnets, second magnets, and main magnets that are arranged in a line corresponding to each other along the central axis, at least one first magnet, its corresponding second magnet, and its corresponding main magnet are arranged in a Halbach arrangement along the central axis. When viewed from a direction perpendicular to the central axis, the rotor main part faces the stator core, and at least a portion of the first rotor end and at least a portion of the second rotor end do not face the stator core.

[0009] The motor according to this disclosure comprises a rotor according to this disclosure and a stator having a stator core.

[0010] The auxiliary rotor according to this disclosure comprises a first auxiliary rotor with a first axis as its central axis and a second auxiliary rotor with a second axis as its central axis, wherein the first auxiliary rotor has a plurality of first auxiliary magnets and the second auxiliary rotor has a plurality of second auxiliary magnets, wherein when viewed along the first axis, each first auxiliary magnet is arranged in a line along the first circumference of a circle centered on the first axis, and when viewed along the second axis, each second auxiliary magnet is arranged in a line along the second circumference of a circle centered on the second axis, and each first auxiliary magnet and each second auxiliary magnet are arranged in a Halbach arrangement along the corresponding first or second circumference, and the first auxiliary rotor and the second auxiliary rotor can be placed on a rotor having a rotor axis, and the first auxiliary rotor and the second auxiliary rotor can be placed at both ends of the rotor core of the rotor in the direction along the rotor axis. [Effects of the Invention]

[0011] According to the rotor, motor, and auxiliary rotor of this disclosure, it is possible to increase the number of magnets by utilizing the space formed inside the stator coil end, while increasing the utilization efficiency of the increased magnets and preventing a decrease in cost efficiency. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram showing a motor according to Embodiment 1. [Figure 2] This is a schematic diagram showing a rotor as an example. [Figure 3] Figure 2 is a schematic diagram showing an example of an improved rotor. [Figure 4] Figure 1 is a schematic diagram illustrating the effect of the rotor. [Figure 5] This is a cross-sectional view along the VV line in Figure 1. [Figure 6] This is a cross-sectional view along the line VI-VI in Figure 1. [Figure 7] This is a cross-sectional view along line VII-VII in Figure 1. [Figure 8] This is a schematic diagram showing the arrangement of the first magnet, the main magnet, and the second magnet in Figure 1. [Figure 9] It is a schematic diagram showing another example of the arrangement of the first magnet, the main part magnet, and the second magnet in FIG. 1. [Figure 10] It is a schematic diagram showing an auxiliary rotor according to Embodiment 2. [Figure 11] It is a cross-sectional view taken along line XI-XI of FIG. 10. [Figure 12] It is a cross-sectional view taken along line XII-XII of FIG. 10. [Figure 13] It is a schematic diagram showing the arrangement of magnets in a state where the auxiliary rotor of FIG. 10 is arranged on the rotor.

Embodiment for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Embodiment 1. FIG. 1 is a schematic diagram showing a motor 1 according to Embodiment 1. The motor 1 includes a housing 2, a stator 4 supported inside the housing 2, and a rotor 5 disposed inside the stator 4 and rotatably supported by the housing 2.

[0014] The motor 1 has a central axis L, and the rotor 5 is rotatable around the central axis L. In FIG. 1, a cross-section along the central axis L of the motor 1 is shown.

[0015] The stator 4 has a cylindrical shape and is supported by the housing 2 such that the central axis of the cylinder is disposed on the central axis L. The stator 4 has a stator core 45 and a coil 50 installed on the stator core 45.

[0016] The stator core 45 is formed by laminating a plurality of metal plates having substantially equal outer shapes in a direction along the central axis L. Note that the configuration of the stator core 45 is not limited to a structure in which a plurality of metal plates are laminated.

[0017] The coil 50 is formed by winding wire around the stator core 45. The stator 4 may also be further provided with a holding member made of resin to allow the coil 50 to be easily wound around the stator core 45, or to hold the coil 50 and the stator core 45 more firmly together.

[0018] The rotor 5 has a rod-shaped rotating shaft 3 that rotates around a central axis in the longitudinal direction, a rotor main section 10, a first rotor end section 20, and a second rotor end section 30. The rotor main section 10, the first rotor end section 20, and the second rotor end section 30 have an annular shape, and a space is formed at the center of each of them into which the rotating shaft 3 is inserted and positioned.

[0019] The rotating shaft 3 is inserted into the spaces formed at the center of the first rotor end 20, the rotor main 10, and the second rotor end 30, and they are fixed to each other. When the rotating shaft 3, the first rotor end 20, the rotor main 10, and the second rotor end 30 are fixed to each other, they are arranged in the order of the first rotor end 20, the rotor main 10, and the second rotor end 30. That is, the first rotor end 20 and the second rotor end 30 are positioned so as to sandwich the rotor main 10 between them.

[0020] The rotor 5 is positioned in the housing 2 such that the longitudinal central axis of the rotation shaft 3 coincides with the central axis L. As a result, the central axes of the rotor main portion 10, the first rotor end portion 20, and the second rotor end portion 30 are also positioned on the central axis L.

[0021] Specifically, the first rotor end 20 is located at one end of the rotor main 10 in the direction along the central axis L. The second rotor end 30 is located at the other end of the rotor main 10, opposite to the one end in the direction along the central axis L. The first rotor end 20, the rotor main 10, and the second rotor end 30 rotate about the central axis L.

[0022] When viewed from a direction perpendicular to the central axis L, the rotor main portion 10 faces the stator core 45. On the other hand, the first rotor end portion 20 and the second rotor end portion 30 do not face the stator core 45. That is, the first rotor end portion 20 and the second rotor end portion 30 are each located in a space formed inside the stator 4.

[0023] Next, the effects of the rotor of this embodiment 1 will be explained. Figure 2 is a schematic diagram showing a rotor 90 as a comparative example. Figure 3 is a schematic diagram showing an improved example of the rotor 90 of Figure 2. Figure 4 is a schematic diagram showing the effects of the rotor 5 of Figure 1.

[0024] Figure 2-4 shows only the rotors 90, 91, and 5 that make up the motor, and their corresponding stators 4. Each rotor 90, 91, and 5 has a rotation axis 3. The rotors 90, 91, and 5 and the corresponding stators 4 shown in Figure 2-4 each have a central axis L, and the central axis of each rotation axis 3 coincides with the central axis L. That is, each rotor 90, 91, and 5 rotates around the central axis L.

[0025] In Figure 2-4, a portion of the rotors 90, 91, and 5, and the corresponding stator 4, are shown as a cross-section along the central axis L. In Figure 2-4, the magnetic flux from the rotors 90, 91, and 5 toward the stator 4 is indicated by arrows.

[0026] Figure 2 illustrates a comparative example rotor 90. The rotor 90 has a rotating shaft 3 and a rotor main section 10 fixed to the rotating shaft 3. The rotor main section 10 has a main rotor core 11 and a plurality of main magnets 12 fixed to the main rotor core 11.

[0027] The rotor 90 is positioned opposite the stator 4. The rotor 90 and stator 4 are supported by a housing (not shown) and constitute a motor. The stator 4 has a stator core 45 and coils 50 arranged in the stator core 45.

[0028] When the motor in Figure 2 is in operation, a magnetic flux is formed from the rotor 5 toward the stator core 45. The magnetic flux from the rotor 5 toward the stator core 45 is distributed almost uniformly along the central axis L.

[0029] Here, improving the efficiency and performance of motors is always a requirement. It is known that motor output can be improved by increasing the magnetic flux from the rotor to the stator. That is, by making the magnets used in the rotor stronger or increasing the number of magnets, the magnetic flux becomes stronger and the motor output can be improved.

[0030] As shown in Figure 2, a space S is formed on both ends of the stator core 45, in the direction toward the central axis L where the coil 50 is located, that is, on the inner circumference side of the coil 50. Therefore, the researchers considered increasing the amount of magnets by making effective use of space S. In other words, they considered placing the main magnet 12 in space S.

[0031] As a result, as shown in Figure 3, we developed a rotor 91 in which the main rotor core 11 and each main magnet 12 are extended in the direction along the central axis L.

[0032] Like rotor 90, rotor 91 also has a rotating shaft 3 and a rotor main section 10 fixed to the rotating shaft 3. The rotor main section 10 has a main rotor core 11 and a plurality of main magnets 12 fixed to the main rotor core 11.

[0033] The main rotor core 11 and each main magnet 12 extend into space S. That is, each main magnet 12 has a portion A that corresponds to space S, and the main rotor core 11 is also extended to correspond to space S, corresponding to the extended portion A of each main magnet 12.

[0034] In this case, the magnetic flux generated by the main magnet 12 in the extended portion, i.e., portion A, is directed towards the stator core 45, as shown in portion B of Figure 3. This is because the stator core 45 is not located in a direction perpendicular to the central axis L in portion A, i.e., not in a position opposite to portion A. The magnetic flux generated by the main magnet 12 in portion A is directed towards the stator core 45, which is located in an oblique direction. This state is shown in portion B of Figure 3.

[0035] In the magnetic flux flow shown in section B, magnetic flux resistance will be generated or increase. Therefore, it was found that the increase in magnetic flux to match the increase in each main magnet 12 in section A, which is the extension to section A, cannot be expected.

[0036] Researchers have increased the number of magnets and thus the magnetic flux by effectively utilizing space S, but have devised the rotor 5 of this disclosure in order to use the increased magnetic flux with even greater efficiency.

[0037] In Figure 4, the first rotor end 20 and the second rotor end 30 are positioned at both ends of the rotor main section 10, i.e., in the space S. The first rotor end 20 has a first rotor core 21 and a plurality of first magnets 22 fixed to the first rotor core 21. Each first magnet 22 is arranged along the circumference of a circle whose center lies on the central axis L.

[0038] The second rotor end 30 has a second rotor core 31 and a plurality of second magnets 32 fixed to the second rotor core 31. Each second magnet 32 ​​is arranged along the circumference of a circle whose center lies on the central axis L.

[0039] At this time, each first magnet 22 is arranged in a Halbach arrangement along the circumference of a circle whose center lies on the central axis L, and each second magnet 32 ​​is arranged in a Halbach arrangement along the circumference of a circle whose center lies on the central axis L.

[0040] Furthermore, at least one of the sets of the first magnet 22, the main magnet 12, and the second magnet 32, which are arranged in a line corresponding to each other along the central axis L, is arranged in a Halbach arrangement along the central axis L.

[0041] As a result, the magnetic flux originating from each first magnet 22 and the magnetic flux originating from each second magnet 32 ​​are However, as shown in Figure 4, the magnetic flux is directed towards the corresponding main magnet 12. As a result, the magnetic flux generated in the rotor main section 10 and directed towards the stator 4 becomes stronger.

[0042] That is, when viewed from a direction perpendicular to the central axis L, the rotor main portion 10 faces the stator core 45, but the first rotor end portion 20 and the second rotor end portion 30 do not face the stator core 45. At least a portion of the first rotor end portion 20 and at least a portion of the second rotor end portion 30 may be positioned in a location corresponding to the space S.

[0043] In other words, a portion of the first rotor end 20 and a portion of the second rotor end 30 may face the stator core 45. Even when at least a portion of the first rotor end 20 and at least a portion of the second rotor end 30 do not face the stator core 45, the direction of the magnetic flux is similarly controlled appropriately, and the magnetic flux generated in the rotor main section 10 and directed toward the stator 4 becomes stronger.

[0044] By arranging the magnets in a Halbach arrangement as described above, the direction of the magnetic flux can be controlled, resulting in a magnetic flux flow with low magnetic flux resistance. In other words, magnetic flux loss can be reduced. The first magnet 22, the main magnet 12, and the second magnet 32 ​​will be described in detail later.

[0045] Next, the first rotor end 20 will be described in more detail. Figure 5 is a cross-sectional view along the VV line in Figure 1. Figure 5 is a cross-sectional view along the central axis L.

[0046] Multiple first magnets 22 are arranged in a line along the circumference C of a circle whose center lies on the central axis L. In Figure 5, the first rotor core 21 has through holes into which each first magnet 22 can be inserted in a direction perpendicular to the plane of the paper, and each first magnet 22 is supported by the first rotor core 21 by being inserted into and fixed in the corresponding through hole.

[0047] Furthermore, the method of fixing each first magnet 22 to the first rotor core 21 is not limited to inserting and fixing it through a through hole. For example, it may be fixed along the outer circumference of the first rotor core 21.

[0048] In Figure 5, the clockwise direction of the circumference C when viewed along the central axis L is defined as the first direction Ca, and the counterclockwise direction opposite to the first direction Ca is defined as the second direction Cb. Each first magnet 22 is one of the first first magnet 22A, second first magnet 22B, third first magnet 22C, and fourth first magnet 22D, which have different magnetic pole directions when placed on the first rotor core 21.

[0049] The first magnet 22A has a magnetic pole direction perpendicular to the plane of the paper and pointing downward. That is, the first magnet 22A has a magnetic pole direction toward the rotor main part 10 along the central axis L. The second magnet 22B has a magnetic pole direction perpendicular to the plane of the paper and pointing upward.

[0050] In other words, the second first magnet 22B has a magnetic pole direction that is opposite to the magnetic pole direction of the first first magnet 22A. The second first magnet 22B has a magnetic pole direction that is away from the rotor main part 10.

[0051] The third first magnet 22C has a magnetic pole direction equal to the tangential direction of the circumference C along the first direction Ca. The fourth first magnet 22D has a magnetic pole direction equal to the tangential direction of the circumference C along the second direction Cb.

[0052] Furthermore, each first magnet 22 is arranged along the circumference C in the order of first-first magnet 22A, third-first magnet 22C, second-first magnet 22B, and fourth-first magnet 22D, and this order is repeated. Here, each first magnet 22 is arranged along the circumference C in a Halbach arrangement.

[0053] Next, the rotor main section 10 will be described in more detail. Figure 6 is a cross-sectional view taken along the line VI-VI in Figure 1. Figure 6 is a cross-sectional view taken along the central axis L.

[0054] Multiple main magnets 12 are arranged in a line along the circumference C of a circle whose center lies on the central axis L. In Figure 6, the main rotor core 11 has through holes formed in a direction perpendicular to the plane of the paper into which each main magnet 12 can be inserted, and each main magnet 12 is supported by the main rotor core 11 by being inserted into and fixed in the corresponding through hole.

[0055] Furthermore, the method of fixing each main magnet 12 to the main rotor core 11 is not limited to inserting and fixing it through a through hole. For example, it may be fixed along the outer circumference of the main rotor core 11.

[0056] In Figure 6, as in Figure 5, the clockwise direction of the circumference C when viewed along the central axis L is the first direction Ca, and the counterclockwise direction is the second direction Cb. In this case, each main magnet 12 is one of the first main magnet 12A, second main magnet 12B, third main magnet 12C, and fourth main magnet 12D, which have different magnetic pole directions when arranged in the main rotor core 11.

[0057] The first main magnet 12A has a magnetic pole direction that is away from the central axis L. The second main magnet 12B has a magnetic pole direction that is toward the central axis L. That is, the second main magnet 12B has a magnetic pole direction that is opposite to the magnetic pole direction of the first main magnet 12A.

[0058] The third main magnet 12C has a magnetic pole direction equal to the tangential direction of the circumference C along the first direction Ca. The fourth main magnet 12D has a magnetic pole direction equal to the tangential direction of the circumference C along the second direction Cb.

[0059] Furthermore, each main magnet 12 is arranged along the circumference C in the order of the first main magnet 12A, the third main magnet 12C, the second main magnet 12B, and the fourth main magnet 12D, and this order is repeated. Here, each main magnet 12 is arranged in a Halbach arrangement along the circumference C.

[0060] Next, the second rotor end 30 will be described in more detail. Figure 7 is a cross-sectional view taken along the line VI-VI in Figure 1. Figure 7 is a cross-sectional view taken along the central axis L.

[0061] Multiple second magnets 32 are arranged in a line along the circumference C of a circle whose center lies on the central axis L. In Figure 7, the second rotor core 31 has through holes into which each second magnet 32 ​​can be inserted in a direction perpendicular to the plane of the paper, and each second magnet 32 ​​is supported by the second rotor core 31 by being inserted into and fixed in the corresponding through hole.

[0062] Furthermore, the method of fixing each second magnet 32 ​​to the second rotor core 31 is not limited to inserting and fixing it through a through hole. For example, it may be fixed along the outer circumference of the second rotor core 31.

[0063] In Figure 7, the clockwise direction of the circumference C when viewed along the central axis L is the first direction Ca, and the counterclockwise direction is the second direction Cb. In this case, each second magnet 32 ​​is one of the first second magnet 32A, second second magnet 32B, third second magnet 32C, and fourth second magnet 32D, which have different magnetic pole directions when placed on the second rotor core 31.

[0064] The first and second magnets 32A have a magnetic pole direction perpendicular to the plane of the paper and pointing upward. That is, the first and second magnets 32A have a magnetic pole direction toward the rotor main part 10 along the central axis L. The second second magnet 32B has a magnetic pole direction perpendicular to the plane of the paper and pointing downward.

[0065] In other words, the second second magnet 32B has a magnetic pole direction opposite to that of the first second magnet 32A. The second second magnet 32B has a magnetic pole direction that moves away from the rotor main body 10.

[0066] The third second magnet 32C has a magnetic pole direction equal to the tangential direction of the circumference C along the first direction Ca. The fourth second magnet 32D has a magnetic pole direction equal to the tangential direction of the circumference C along the second direction Cb.

[0067] Furthermore, each second magnet 32 ​​is arranged along the circumference C in the order of first second magnet 32A, third second magnet 32C, second second magnet 32B, and fourth second magnet 32D, and this order is repeated. Here, each second magnet 32 ​​is arranged along the circumference C in a Halbach arrangement.

[0068] Next, we will explain the arrangement of each first magnet 22, each main magnet 12, and each second magnet 32. Figure 8 is a schematic diagram showing the arrangement of the first magnet 22, main magnet 12, and second magnet 32 ​​in Figure 1. Figure 8 shows a portion of each first magnet 22, each main magnet 12, and each second magnet 32, which are arranged along the circumference C of a circle with its center on the central axis L, unfolded on the paper.

[0069] Figure 8 shows the arrangement of parts of the first magnets 22, main magnets 12, and second magnets 32 of the rotor 5 as viewed from the outer circumference toward the central axis L. In Figure 8, the vertical direction of the paper is considered to be along the central axis L, the direction toward the left of the paper is the first direction Ca, and the direction toward the right of the paper is the second direction.

[0070] As mentioned above, each of the first magnets 22, each of the main magnets 12, and each of the second magnets 32 are arranged in a Halbach arrangement along the circumference C. In Figure 8, the arrangement of magnets in a Halbach arrangement is shown enclosed by a dashed line.

[0071] When viewed from a direction perpendicular to the central axis L, each main magnet 12, its corresponding first magnet 22, and its corresponding second magnet 32 ​​are arranged in a line along the central axis L. Furthermore, the combination of each main magnet 12, its corresponding first magnet 22, and its corresponding second magnet 32 ​​arranged in a line along the central axis L is one of the following four combinations.

[0072] The first combination is the first main magnet 12A, the first first magnet 22A, and the first second magnet 32A. The second combination is the second main magnet 12B, the second first magnet 22B, and the second second magnet 32B.

[0073] The third combination is the third main magnet 12C, the third first magnet 22C, and the third second magnet 32C. The last combination is the fourth main magnet 12D, the fourth first magnet 22D, and the fourth second magnet 32D.

[0074] In this case, the combination of the first main magnet 12A, the first first magnet 22A, and the first second magnet 32A, and the combination of the second main magnet 12B, the second first magnet 22B, and the second second magnet 32B, are in a Halbach arrangement. That is, among the combinations of each main magnet 12, the corresponding first magnet 22, and the corresponding second magnet 32, which are arranged in a line corresponding to each other along the central axis L, at least one or more combinations of the main magnet 12, the corresponding first magnet 22, and the corresponding second magnet 32 ​​are in a Halbach arrangement.

[0075] Next, we will describe a different arrangement of magnets from the arrangement of magnets shown in Figure 8. Figure 9 is a schematic diagram showing another example of the arrangement of the first magnet 22, the main magnet 12, and the second magnet 32 ​​in Figure 1.

[0076] Figure 9 shows, similar to Figure 8, a portion of each first magnet 22, each main magnet 12, and each second magnet 32, arranged along the circumference C of a circle whose center lies on the central axis L, unfolded on the paper.

[0077] Figure 9 shows the arrangement of some of the first magnets 22, main magnets 12, and second magnets 32 of the rotor 5 as viewed from the outer circumference toward the central axis L. In Figure 9, the vertical direction of the paper corresponds to the direction along the central axis L, and the horizontal direction of the paper corresponds to the direction along the circumference C. In Figure 9, the arrangement of magnets in a Halbach arrangement is also shown enclosed by a dashed line.

[0078] As shown in Figure 9, the combinations of each main magnet 12 arranged in a line along the central axis L, the corresponding first magnet 22, and the corresponding second magnet 32 ​​may be one of the following four combinations.

[0079] The first combination is the combination of the fourth main magnet 12D, the first first magnet 22A, and the first second magnet 32A. The second combination is the combination of the third main magnet 12C, the second first magnet 22B, and the second second magnet 32B.

[0080] The third combination is the second main magnet 12B, the fourth first magnet 22D, and the fourth second magnet 32D. The last combination is the first main magnet 12A, the third first magnet 22C, and the third second magnet 32C.

[0081] In this case, the combination of the second main magnet 12B, the fourth first magnet 22D, and the fourth second magnet 32D, and the combination of the first main magnet 12A, the third first magnet 22C, and the third second magnet 32C, are in a Halbach arrangement. That is, even in this case, among the combinations of each main magnet 12, the corresponding first magnet 22, and the corresponding second magnet 32 ​​arranged in a line corresponding to each other along the central axis L, at least one or more combinations of the main magnet 12, the corresponding first magnet 22, and the corresponding second magnet 32 ​​are in a Halbach arrangement.

[0082] Comparing Figure 8 and Figure 9, the combinations of second magnets 32 corresponding to each first magnet 22 are the same in both Figure 8 and Figure 9.

[0083] In other words, the combination of second magnets 32 corresponding to each first magnet 22 arranged along the central axis L is one of the following four combinations: The first combination is the first first magnet 22A and the first second magnet 32A. The second combination is the second first magnet 22B and the second second magnet 32B. The third combination is the third first magnet 22C and the third second magnet 32C. The last combination is the fourth first magnet 22D and the fourth second magnet 32D.

[0084] The overall arrangement is determined by which magnetic pole direction the main magnet 12 has when placed in relation to the combination of the first magnet 22 and the second magnet 32 ​​described above.

[0085] In Embodiment 1, the rotor main section 10 has one main magnet 12 arranged along the central axis L. However, it is not limited to this. For example, multiple main magnets 12 may be arranged along the central axis L. In this case as well, it is sufficient that at least one of the combinations formed by the first magnet 22, multiple main magnets 12, and second magnet 32 ​​arranged in a line corresponding to each other along the central axis L is arranged in a Halbach arrangement.

[0086] Furthermore, in Embodiment 1, each of the first rotor end 20 and the second rotor end 30 has one first magnet 22 and one second magnet 32 ​​arranged in the direction along the central axis L. However, it is not limited to this. Multiple first magnets 22 and multiple second magnets 32 may be arranged in the direction along the central axis L. In this case as well, in the combinations formed by multiple first magnets 22, main magnets 12, and multiple second magnets 32 arranged in a line corresponding to each other in the direction along the central axis L, it is sufficient that at least one of the multiple combinations is arranged in a Halbach arrangement.

[0087] Furthermore, in Embodiment 1, each of the rotor main portion 10, the first rotor end portion 20, and the second rotor end portion 30 has one main portion magnet 12, one first magnet 22, and one second magnet 32 ​​arranged in the direction along the central axis L. However, it is not limited to this. For example, multiple main portion magnets 12, multiple first magnets 22, and multiple second magnets 32 may be arranged in the direction along the central axis L. In this case as well, it is sufficient that at least one of the combinations formed by the multiple first magnets 22, multiple main portion magnets 12, and multiple second magnets 32 arranged in a line corresponding to each other in the direction along the central axis L is arranged in a Halbach arrangement.

[0088] Furthermore, the rotor 5 in Embodiment 1 is shown as an IPM rotor in a rotary inner motor. However, it is not limited to this. For example, it may also be applied to an SPM rotor, a rotary outer rotor motor, an AC servo motor, and a linear motor.

[0089] Furthermore, in Embodiment 1, each main magnet 12 of the rotor 5 uses magnets with equal magnetic force. However, this is not the only option. For example, the first main magnet 12A and the second main magnet 12B may be used as the main pole magnets, and the third main magnet 12C and the fourth main magnet 12D may be used as the auxiliary pole magnets. Moreover, the auxiliary pole magnets may have a weaker magnetic force than the main pole magnets.

[0090] Furthermore, in Embodiment 1, each first magnet 22 and each second magnet 32 ​​of the rotor 5 are magnets having equal magnetic force. However, this is not the only option. For example, the first first magnet 22A, the second first magnet 22B, the first second magnet 32A, and the second second magnet 32B may be used as the main pole magnets, and the third first magnet 22C, the fourth first magnet 22D, the third second magnet 32C, and the fourth second magnet 32D may be used as the co-pole magnets. Moreover, the co-pole magnets may have a weaker magnetic force than the main pole magnets.

[0091] The rotor 5 in Embodiment 1 includes a rotor main section 10 that rotates about a central axis L. The rotor 5 also includes a first rotor end section 20 located at one end of the rotor main section 10 in the direction along the central axis L. The rotor 5 also includes a second rotor end section 30 located at the other end of the rotor main section 10 opposite to the one end in the direction along the central axis L. The rotor main section 10 has a plurality of main magnets 12, the first rotor end section 20 has a plurality of first magnets 22, and the second rotor end section 30 has a plurality of second magnets 32. When viewed along the central axis L, each of the main magnets 12, each of the first magnets 22, and each of the second magnets 32 are arranged in a line along the circumference C of a circle whose center lies on the central axis L. Furthermore, each of the first magnets 22 and each of the second magnets 32 are arranged in a Halbach arrangement along the corresponding circumference C. Furthermore, when viewed from a direction perpendicular to the central axis L, each main magnet 12, its corresponding first magnet 22, and its corresponding second magnet 32 ​​are arranged in a line along the central axis L. In addition, of the first magnets 22, second magnets 32, and main magnets 12 that are arranged in a line corresponding to each other along the central axis L, at least one first magnet 22, its corresponding second magnet 32, and its corresponding main magnet 12 are arranged in a Halbach arrangement along the central axis L. Furthermore, when viewed from a direction perpendicular to the central axis L, the rotor main portion 10 faces the stator core 45, while at least a portion of the first rotor end 20 and at least a portion of the second rotor end 30 do not face the stator core 45. As a result, the first rotor end 20 and the second rotor end 30, which have magnets arranged in a Halbach pattern in the circumferential direction, are positioned inside the stator coil end, and at least one set of the first magnet 22, main magnet 12, and second magnet 32, which are aligned along the central axis L, are arranged in a Halbach pattern. Therefore, the number of magnets can be increased by utilizing the space formed inside the stator coil end, and the utilization efficiency of the increased magnets can be increased. Thus, a rotor 5 can be provided that prevents a decrease in cost efficiency.Furthermore, by installing the first rotor end 20 and the second rotor end 30 on the rotor main part 10, a Halbach array can be formed including the first magnet 22 and the second magnet 32 ​​in addition to the main part magnets 12, thereby increasing the magnetic flux. Consequently, by using the rotor 5, it is possible to increase the motor output and reduce the heat generated by the motor.

[0092] In the rotor 5 according to Embodiment 1, each main magnet 12 is arranged in a Halbach arrangement along the circumference C. As a result, each main magnet 12 also adopts a Halbach arrangement, which allows for increased magnetic flux even when using magnets with weak magnetic flux for the secondary poles. Therefore, a rotor 5 with excellent cost performance of magnets relative to torque can be provided.

[0093] Furthermore, in the rotor 5 according to Embodiment 1, when viewed along the central axis L, one direction in the circumferential direction of the circumference C is the first direction Ca, and the other direction in the circumferential direction of the circumference C opposite to the first direction Ca is the second direction Cb. When viewed along the central axis L, each first magnet 22 is one of the following: a first first magnet 22A having a magnetic pole direction toward the rotor main part 10 along the central axis L; a second first magnet 22B having a magnetic pole direction toward the opposite direction to the magnetic pole direction of the first first magnet 22A; a third first magnet 22C having a magnetic pole direction equal to the tangential direction of the circumference C along the first direction Ca; and a fourth first magnet 22D having a magnetic pole direction equal to the tangential direction of the circumference C along the second direction Cb. Also, each first magnet 22 is arranged along the circumference C in the order of first first magnet 22A, third first magnet 22C, second first magnet 22B, and fourth first magnet 22D, and this order is repeated. Furthermore, when viewed along the central axis L, each second magnet 32 ​​is one of the following: a first second magnet 32A having a magnetic pole direction toward the rotor main part 10 along the central axis L; a second second magnet 32B having a magnetic pole direction opposite to the magnetic pole direction of the first second magnet 32A; a third second magnet 32C having a magnetic pole direction equal to the tangential direction of the circumference C along the first direction Ca; and a fourth second magnet 32D having a magnetic pole direction equal to the tangential direction of the circumference C along the second direction Cb. In addition, the combinations of each first magnet 22 arranged along the central axis L and the corresponding second magnet 32 ​​are one of the following: a first first magnet 22A and a first second magnet 32A; a second first magnet 22B and a second second magnet 32B; a third first magnet 22C and a third second magnet 32C; and a fourth first magnet 22D and a fourth second magnet 32D. As a result, the first magnet 22 and the second magnet 32, which are arranged periodically in the circumferential direction, are arranged symmetrically with respect to each other. Therefore, the regular arrangement of the first magnet 22 and the second magnet 32 ​​results in a symmetrical magnetic flux flow. Consequently, a rotor 5 can be provided in which the magnetic flux flow can be set more easily. Furthermore, a balanced magnetic flux can be generated at both ends in the direction along the central axis L. Thus, a rotor 5 that operates stably can be provided.

[0094] Furthermore, in the rotor 5 according to Embodiment 1, when viewed along the central axis L, each main magnet 12 is one of the following: a first main magnet 12A having a magnetic pole direction away from the central axis L; a second main magnet 12B having a magnetic pole direction toward the central axis L; a third main magnet 12C having a magnetic pole direction equal to the tangential direction of the circumference C along the first direction Ca; and a fourth main magnet 12D having a magnetic pole direction equal to the tangential direction of the circumference C along the second direction Cb. Also, each main magnet 12 is arranged along the circumference C in the order of the first main magnet 12A, the third main magnet 12C, the second main magnet 12B, and the fourth main magnet 12D, and this order is repeated. As a result, each main magnet 12 is arranged with periodicity in the circumferential direction. Therefore, a rotor 5 can be provided in which the magnetic flux flow of the rotor main part 10 can be easily set.

[0095] In the rotor 5 according to Embodiment 1, the combination of each main magnet 12 arranged along the central axis L, the corresponding first magnet 22, and the corresponding second magnet 32 ​​is one of the following: the first main magnet 12A, the first first magnet 22A, and the first second magnet 32A; the second main magnet 12B, the second first magnet 22B, and the second second magnet 32B; the third main magnet 12C, the third first magnet 22C, and the third second magnet 32C; and the fourth main magnet 12D, the fourth first magnet 22D, and the fourth second magnet 32D. This makes it possible to generate a balanced magnetic flux. Therefore, a rotor 5 that operates stably can be provided.

[0096] In the rotor 5 according to Embodiment 1, the combination of each main magnet 12 arranged along the central axis L, the corresponding first magnet 22, and the corresponding second magnet 32 ​​is one of the following: the combination of the fourth main magnet 12D with the first first magnet 22A and the first second magnet 32A; the combination of the third main magnet 12C with the second first magnet 22B and the second second magnet 32B; the combination of the second main magnet 12B with the fourth first magnet 22D and the fourth second magnet 32D; and the combination of the first main magnet 12A with the third first magnet 22C and the third second magnet 32C. This makes it possible to generate a balanced magnetic flux. Therefore, a rotor 5 that operates stably can be provided.

[0097] In the rotor 5 according to Embodiment 1, a plurality of main magnets 12 are arranged in a line along the central axis L. Furthermore, of the first magnets 22, second magnets 32, and plurality of main magnets 12 arranged in a line corresponding to each other along the central axis L, at least one first magnet 22, the corresponding second magnet 32, and the corresponding plurality of main magnets 12 are arranged in a Halbach arrangement along the central axis L. As a result, even if multiple stages of main magnets 12 are arranged in the rotor main portion 10, the rotor has a first rotor end 20 and a second rotor end 30 having magnets arranged in a Halbach arrangement in the circumferential direction, and furthermore, at least one set of the first magnets 22, plurality of main magnets 12, and second magnets 32 arranged along the central axis L is in a Halbach arrangement.Therefore, it is possible to increase the number of magnets by utilizing the space formed inside the stator coil end, and to increase the utilization efficiency of the increased magnets. Thus, a rotor 5 can be provided that prevents a decrease in cost efficiency. Furthermore, by installing the first rotor end 20 and the second rotor end 30 at both ends of the rotor main 10, a Halbach array can be formed including the first magnet 22 and the second magnet 32 ​​in addition to the main magnets 12, thereby increasing the magnetic flux. Consequently, it is possible to increase the output of the motor using the rotor 5 and reduce heat generation.

[0098] The motor 1 according to Embodiment 1 comprises a rotor 5 and a stator 4 having a stator core 45. This allows for an increase in the number of magnets by utilizing the space formed inside the stator coil ends, while simultaneously increasing the utilization efficiency of the increased magnets. Therefore, a motor 1 using a rotor 5 that prevents a decrease in cost efficiency can be provided. Furthermore, by installing the first rotor end 20 and the second rotor end 30 at both ends of the rotor main portion 10, a Halbach array can be formed including the first magnet 22 and the second magnet 32 ​​in addition to the main portion magnets 12, thereby increasing the magnetic flux. Consequently, the output of the motor 1 can be increased and heat generation can be reduced.

[0099] Embodiment 2. The first auxiliary rotor 110 and the second auxiliary rotor 120 of the auxiliary rotor 100 in Embodiment 2 differ from the first rotor end 20 and the second rotor end 30 of Embodiment 1 in that they can be mounted on an existing rotor 150.

[0100] Figure 10 is a schematic diagram showing the auxiliary rotor 100 according to Embodiment 2. Figure 10 shows the auxiliary rotor 100 positioned on the existing rotor 150. Figure 10 shows cross-sections of the rotor 150 and the auxiliary rotor 100 along the rotor axis L150. The rotor axis L150 will be explained later.

[0101] The auxiliary rotor 100 comprises a first auxiliary rotor 110 and a second auxiliary rotor 120. The first auxiliary rotor 110 and the second auxiliary rotor 120 can each be mounted on an existing rotor 150.

[0102] First, let's describe the existing rotor 150. The existing rotor 150 is housed inside a housing (not shown) which contains a stator (not shown), and constitutes a motor. The rotor 150 has a rotor axis L150. The rotor 150 rotates around the rotor axis L150 relative to the housing and the stator.

[0103] The rotor 150 includes a rotating shaft 151, a rotor core 152 positioned on the rotating shaft 151, and a plurality of rotor magnets 153 positioned on the rotor core 152. The rotating shaft 151 and the rotor core 152 are fixed to each other such that their respective central axes lie on the same axis, which is the rotor axis L150.

[0104] Each rotor magnet 153 is arranged on the rotor core 152 along the circumference of a circle whose center lies on the rotor axis L150, when viewed along the rotor axis L150. In this case, each rotor magnet 153 may be arranged on the rotor core 152 in a well-known manner.

[0105] Let's describe the auxiliary rotor 100. The first auxiliary rotor 110 has an annular shape and has a first axis L10 as a central axis passing through the center of the annulus. The first auxiliary rotor 110 has a first auxiliary core 111 and a plurality of first auxiliary magnets 112 arranged on the first auxiliary core 111. Each first auxiliary magnet 112 is arranged along the circumference of a circle whose center lies on the first axis L10 when viewed along the first axis L10.

[0106] The second auxiliary rotor 120 has an annular shape and has a second axis L20 as a central axis passing through the center of the annule. The second auxiliary rotor 120 includes a second auxiliary core 121 and a plurality of second auxiliary magnets 122 arranged on the second auxiliary core 121. Each second auxiliary magnet 122 is arranged along the circumference of a circle whose center lies on the second axis L20 when viewed along the second axis L20.

[0107] When the auxiliary rotor 100 is to be placed on the existing rotor 150, the existing rotor 150 is removed from the housing as necessary. If further necessary, the rotor core 152 and the rotating shaft 151 are disassembled.

[0108] The first auxiliary rotor 110 and the second auxiliary rotor 120 are positioned at both ends of the rotor core 152 in the direction along the rotor axis L150. The first auxiliary rotor 110 and the second auxiliary rotor 120 are positioned such that their first axis L10 and second axis L20 coincide with the rotor axis L150.

[0109] With the first auxiliary rotor 110 and the second auxiliary rotor 120 positioned in contact with both ends of the rotor core 152, the first auxiliary rotor 110, the second auxiliary rotor 120, and the rotor core 152 are positioned and fixed to the rotating shaft 151. In this case, if an existing rotating shaft 151 is used, it may be modified to change its shape as needed. Alternatively, a new component that fits the auxiliary rotor 100 positioned on the rotor core 152 may be used as the new rotating shaft 151.

[0110] Next, the first auxiliary rotor 110 will be described in detail. Figure 11 is a cross-sectional view along the line XI-XI in Figure 10. Figure 11 is a cross-sectional view along the first axis L10.

[0111] Multiple first auxiliary magnets 112 are arranged in a line along the first circumference C10 of a circle whose center lies on the first axis L10. In Figure 11, the first auxiliary core 111 has through holes formed in a direction perpendicular to the plane of the paper into which each first auxiliary magnet 112 can be inserted, and each first auxiliary magnet 112 is supported by the first auxiliary core 111 by being inserted into and fixed in the corresponding through hole.

[0112] Furthermore, the method of fixing each first auxiliary magnet 112 to the first auxiliary core 111 is not limited to being inserted into and fixed through a through hole. For example, they may be fixed along the outer circumference of the first auxiliary core 111.

[0113] In Figure 11, the clockwise direction of the first circumference C10 when viewed along the first axis L10 is defined as the first first direction C10a, and the counterclockwise direction opposite to the first first direction C10a is defined as the second first direction C10b. In this case, each first auxiliary magnet 112 is one of the first first auxiliary magnet 112A, second first auxiliary magnet 112B, third first auxiliary magnet 112C, and fourth first auxiliary magnet 112D, which have different magnetic pole directions when placed on the first rotor core 21.

[0114] The first auxiliary magnet 112A has a magnetic pole direction perpendicular to the plane of the paper and pointing downward. That is, the first auxiliary magnet 112A has a magnetic pole direction pointing in one direction along the first axis L10. The second auxiliary magnet 112B has a magnetic pole direction perpendicular to the plane of the paper and pointing upward.

[0115] In other words, the second auxiliary magnet 112B has a magnetic pole direction opposite to that of the first auxiliary magnet 112A. The second auxiliary magnet 112B has a magnetic pole direction that moves away from the rotor core 152.

[0116] The third first auxiliary magnet 112C has a magnetic pole direction equal to the tangential direction of the first circumference C10 along the first first direction C10a. The fourth first auxiliary magnet 112D has a magnetic pole direction equal to the tangential direction of the first circumference C10 along the second first direction C10b.

[0117] Furthermore, each first auxiliary magnet 112 is arranged along the first circumference C10 in the order of first first auxiliary magnet 112A, third first auxiliary magnet 112C, second first auxiliary magnet 112B, and fourth first auxiliary magnet 112D, and this order is repeated. Here, each first auxiliary magnet 112 is arranged in a Halbach arrangement along the first circumference C10.

[0118] Next, the second auxiliary rotor 120 will be described in detail. Figure 12 is a cross-sectional view along the line XII-XII in Figure 10. Figure 12 is a cross-sectional view along the second axis L20.

[0119] Multiple second auxiliary magnets 122 are arranged in a line along the second circumference C20 of a circle whose center lies on the second axis L20. In Figure 12, the second auxiliary core 121 has through holes into which each second auxiliary magnet 122 can be inserted in a direction perpendicular to the plane of the paper, and each second auxiliary magnet 122 is supported by the second auxiliary core 121 by being inserted into and fixed in the corresponding through hole.

[0120] Furthermore, the method of fixing each second auxiliary magnet 122 to the second auxiliary core 121 is not limited to being inserted into and fixed through a through hole. For example, they may be fixed along the outer circumference of the second auxiliary core 121.

[0121] In Figure 12, the clockwise direction of the second circumference C20 when viewed along the second axis L20 is defined as the first second direction C20a, and the counterclockwise direction opposite to the first second direction C20a is defined as the second second direction C20b. In this case, each second auxiliary magnet 122 is one of the first second auxiliary magnet 122A, second second auxiliary magnet 122B, third second auxiliary magnet 122C, and fourth second auxiliary magnet 122D, which have different magnetic pole directions when arranged on the first rotor core 21.

[0122] The first and second auxiliary magnets 122A have a magnetic pole direction perpendicular to the plane of the paper and pointing upward. That is, the first and second auxiliary magnets 122A have a magnetic pole direction pointing in one direction along the second axis L20. The second auxiliary magnet 122B has a magnetic pole direction perpendicular to the plane of the paper and pointing downward.

[0123] In other words, the second auxiliary magnet 122B has a magnetic pole direction opposite to that of the first auxiliary magnet 122A. The second auxiliary magnet 122B has a magnetic pole direction that moves away from the rotor core 152.

[0124] The third auxiliary magnet 122C has a magnetic pole direction equal to the tangential direction of the second circumference C20 along the first direction C20a. The fourth auxiliary magnet 122D has a magnetic pole direction equal to the tangential direction of the second circumference C20 along the second direction C20b.

[0125] Furthermore, each second auxiliary magnet 122 is arranged along the second circumference C20 in the order of first second auxiliary magnet 122A, third second auxiliary magnet 122C, second second auxiliary magnet 122B, and fourth second auxiliary magnet 122D, and this order is repeated. Here, each second auxiliary magnet 122 is arranged in a Halbach arrangement along the second circumference C20.

[0126] Returning to Figure 10, we will further explain the arrangement of the auxiliary rotor 100 on the rotor 150. As can be seen in Figure 10, the first auxiliary rotor 110 and the second auxiliary rotor 120 are positioned on both ends of the rotor core 152 such that their respective central axes, the first axis L10 and the second axis L20, overlap with the rotor axis L150 of the rotor 150. Therefore, the rotor axis L150, the first axis L10, and the second axis L20 extend in the same straight line.

[0127] The first auxiliary rotor 110 and the second auxiliary rotor 120 are positioned at both ends of the rotor core 152 such that, when viewed along the rotor axis L150, their first direction C10a and first second direction C20a face the same direction. Similarly, their second first direction C10b and second second direction C20b face the same direction.

[0128] In this state, the first auxiliary rotor 110 and the second auxiliary rotor 120 are positioned and fixed to the rotor 150.

[0129] Figure 13 is a schematic diagram showing the arrangement of magnets when the auxiliary rotor 100 from Figure 10 is positioned on the rotor 150. In Figure 13, the arrangement of some of the first auxiliary magnets 112, rotor magnets 153, and second auxiliary magnets 122 is shown on the paper, when the rotor 150 with the auxiliary rotor 100 positioned is viewed from the outer circumference toward the rotor axis L150.

[0130] In Figure 13, the vertical direction of the paper corresponds to the direction along the rotor axis L150, the first axis L10, and the second axis L20. In Figure 13, the horizontal direction of the paper corresponds to the direction along the first circumference C10 and the second circumference C20. Furthermore, the first first direction C10a and the first second direction C20a correspond to the direction from the right side of the paper to the left side, and the second first direction C10b and the second second direction C20b correspond to the direction from the left side of the paper to the right side.

[0131] As mentioned above, each first auxiliary magnet 112 is arranged in a Halbach arrangement along the first circumference C10, and each second auxiliary magnet 122 is arranged in a Halbach arrangement along the second circumference C20. In Figure 13, the arrangement of magnets in a Halbach arrangement is shown enclosed by a dashed line.

[0132] When viewed from a direction perpendicular to the rotor axis L150, each rotor magnet 153, its corresponding first auxiliary magnet 112, and its corresponding second auxiliary magnet 122 are arranged in a line along the rotor axis L150 in correspondence with each other. Furthermore, the combination of the first auxiliary magnet 112 and the second auxiliary magnet 122, which are arranged in a line along the rotor axis L150 in correspondence with each other, is one of the following four combinations.

[0133] The first combination is the first auxiliary magnet 112A and the first auxiliary magnet 122A. The second combination is the second first auxiliary magnet 112B and the second second auxiliary magnet 122B.

[0134] The third combination is the third-first auxiliary magnet 112C and the third-second auxiliary magnet 122C. The last combination is the fourth-first auxiliary magnet 112D and the fourth-second auxiliary magnet 122D.

[0135] In other words, the first auxiliary rotor 110 and the second auxiliary rotor 120 are arranged on the rotor 150 such that the combination of the first auxiliary magnet 112 and the second auxiliary magnet 122, which are lined up in a row along the rotor axis L150, results in the four combinations described above.

[0136] The first auxiliary rotor 110 and the second auxiliary rotor 120 are positioned on the rotor core 152 such that the first direction C10a and the first second direction C20a point in the same direction to each other. Therefore, the magnetic pole directions of the first auxiliary magnet 112A and the magnetic pole directions of the first second auxiliary magnet 122A are opposite to each other in the direction along the rotor axis L150. The magnetic pole directions of the second first auxiliary magnet 112B and the magnetic pole directions of the second second auxiliary magnet 122B are moving away from each other in the direction along the rotor axis L150.

[0137] Specifically, the first auxiliary rotor 110 and the second auxiliary rotor 120 are arranged such that the magnetic pole directions of the first auxiliary magnet 112A and the magnetic pole directions of the first auxiliary magnet 122A face each other along the rotor axis L150, and the magnetic pole directions of the second auxiliary magnet 112B and the magnetic pole directions of the second auxiliary magnet 122B move away from each other along the rotor axis L150.

[0138] Furthermore, as can be seen in Figure 13, the rotor 150 is arranged in a Halbach arrangement, with each rotor magnet 153 positioned along the circumference of a circle whose center lies on the rotor axis L150. In addition, sets of rotor magnets 153, first auxiliary magnets 112A and first auxiliary magnets 122A, and sets of rotor magnets 153, second auxiliary magnets 112B and second auxiliary magnets 122B are arranged in a Halbach arrangement along the rotor axis L150.

[0139] Specifically, the auxiliary rotor 100 is positioned on the rotor core 152 such that at least one of the multiple sets of first auxiliary magnets 112, rotor magnets 153, and second auxiliary magnets 122, which are arranged in a line corresponding to each other along the rotor axis L150, forms a Halbach arrangement.

[0140] In Embodiment 2, each rotor magnet 153 is arranged in a Halbach arrangement along the circumference of a circle centered on the rotor axis L150. However, it is not limited to this. The rotor 150 on which the auxiliary rotor 100 is arranged may not have each rotor magnet 153 arranged in a Halbach arrangement along the circumference of a circle centered on the rotor axis L150.

[0141] Furthermore, in Embodiment 2, one rotor magnet 153 is arranged in the rotor core 152 in a direction along the rotor axis L150. However, it is not limited to this. For example, multiple rotor magnets 153 may be arranged in the direction along the rotor axis L150. In this case as well, in the combinations formed by the first auxiliary magnet 112, the multiple rotor magnets 153, and the second auxiliary magnet 122, which are arranged in a line corresponding to each other in the direction along the rotor axis L150, at least one of the multiple combinations may be arranged in a Halbach arrangement.

[0142] Furthermore, in Embodiment 2, the first auxiliary rotor 110 has one first auxiliary magnet 112 arranged in the direction along the first axis L10, and the second auxiliary rotor 120 has one second auxiliary magnet 122 arranged in the direction along the second axis L20. However, it is not limited to this. Multiple first auxiliary magnets 112 may be arranged in the direction along the first axis L10, and multiple second auxiliary magnets 122 may be arranged in the direction along the second axis L20. In this case as well, when the auxiliary rotor 100 is positioned on the rotor 150, at least one of the combinations of multiple first auxiliary magnets 112, rotor magnets 153, and multiple second auxiliary magnets 122 arranged in a line corresponding to each other in the direction along the rotor axis L150 may be arranged in a Halbach arrangement.

[0143] Furthermore, the auxiliary rotor 100 in Embodiment 2 is shown as being compatible with an IPM rotor in a rotary inner motor. However, it is not limited to this. For example, it may be applied to an SPM rotor, a rotary outer rotor motor, an AC servo motor, and a linear motor.

[0144] Furthermore, in Embodiment 2, each first auxiliary magnet 112 and each second auxiliary magnet 122 of the auxiliary rotor 100 are magnets having equal magnetic force. However, this is not the only option. For example, the first first auxiliary magnet 112A, the second first auxiliary magnet 112B, the first second auxiliary magnet 122A, and the second second auxiliary magnet 122B may be used as the main pole magnets, and the third first auxiliary magnet 112C, the fourth first auxiliary magnet 112D, the third second auxiliary magnet 122C, and the fourth second auxiliary magnet 122D may be used as the complementary pole magnets. Moreover, the complementary pole magnets may have a weaker magnetic force than the main pole magnets.

[0145] Furthermore, in Embodiment 2, each rotor magnet 153 uses a magnet having the same magnetic force. However, this is not the only option. For example, some of the rotor magnets 153 may be used as main pole magnets and others as co-pole magnets. Moreover, the co-pole magnets may have a weaker magnetic force than the main pole magnets.

[0146] The auxiliary rotor 100 in Embodiment 2 comprises a first auxiliary rotor 110 with a first axis L10 as its central axis, and a second auxiliary rotor 120 with a second axis L20 as its central axis. The first auxiliary rotor 110 has a plurality of first auxiliary magnets 112, and the second auxiliary rotor 120 has a plurality of second auxiliary magnets 122. When viewed along the first axis L10, each first auxiliary magnet 112 is arranged along the first circumference C10 of a circle centered on the first axis L10. When viewed along the second axis L20, each second auxiliary magnet 122 is arranged along the second circumference C20 of a circle centered on the second axis L20. Furthermore, each first auxiliary magnet 112 and each second auxiliary magnet 122 are arranged in a Halbach arrangement along the corresponding first circumference C10 or second circumference C20. The first auxiliary rotor 110 and the second auxiliary rotor 120 can be mounted on a rotor 150 having a rotor axis L150. Furthermore, the first auxiliary rotor 110 and the second auxiliary rotor 120 can be positioned at both ends of the rotor core 152 of the rotor 150, in the direction along the rotor axis L150. This allows the first auxiliary rotor 110 and the second auxiliary rotor 120 to be positioned on the existing rotor 150. Therefore, the number of magnets can be increased by utilizing the space formed inside the stator coil end of the existing rotor 150, while simultaneously increasing the utilization efficiency of the increased magnets. Thus, the existing rotor 150 can be improved without reducing cost efficiency.

[0147] In Embodiment 2, the auxiliary rotor 100, when viewed along the first axis L10, has one direction in the circumferential direction of the first circumference C10 as the first first direction C10a, and the other direction in the circumferential direction of the first circumference C10 opposite to the first first direction C10a as the second first direction C10b. Furthermore, when viewed along the first axis L10, each first auxiliary magnet 112 is one of the following: a first first auxiliary magnet 112A having a magnetic pole direction toward one direction along the first axis L10; a second first auxiliary magnet 112B having a magnetic pole direction toward the opposite direction to the magnetic pole direction of the first first auxiliary magnet 112A; a third first auxiliary magnet 112C having a magnetic pole direction equal to the tangential direction of the first circumference C10 along the first first direction C10a; and a fourth first auxiliary magnet 112D having a magnetic pole direction equal to the tangential direction of the first circumference C10 along the second first direction C10b. Furthermore, each first auxiliary magnet 112 is arranged along the first circumference C10 in the order of first first auxiliary magnet 112A, third first auxiliary magnet 112C, second first auxiliary magnet 112B, and fourth first auxiliary magnet 112D, and this order is repeated. Also, when viewed along the second axis L20, one direction in the circumferential direction of the second circumference C20 is called the first second direction C20a, and the other direction in the circumferential direction of the second circumference C20, opposite to the first second direction C20a, is called the second second direction C20b. Furthermore, when viewed along the second axis L20, each second auxiliary magnet 122 is one of the following: a first-second auxiliary magnet 122A having a magnetic pole direction pointing in one direction along the second axis L20; a second-second auxiliary magnet 122B having a magnetic pole direction pointing in the opposite direction to the magnetic pole direction of the first-second auxiliary magnet 122A; a third-second auxiliary magnet 122C having a magnetic pole direction equal to the tangential direction of the second circumference C20 along the first-second direction C20a; and a fourth-second auxiliary magnet 122D having a magnetic pole direction equal to the tangential direction of the second circumference C20 along the second-second direction C20b. In addition, each second auxiliary magnet 122 is arranged along the second circumference C20 in the order of first-second auxiliary magnet 122A, third-second auxiliary magnet 122C, second-second auxiliary magnet 122B, and fourth-second auxiliary magnet 122D, and this order is repeated. As a result, the first auxiliary rotor 110 and the second auxiliary rotor 120 each have magnets arranged periodically in the circumferential direction. Therefore, the regular arrangement of the first auxiliary magnet 112 and the second auxiliary magnet 122 makes it easier to predict the flow of magnetic flux. Consequently, an auxiliary rotor 100 can be provided that allows for easier setting of the magnetic flux flow in the existing rotor 150. Furthermore, a balanced magnetic flux can be generated at both ends in the direction along the central axis L. Thus, a rotor 150 that operates stably can be provided.

[0148] In the auxiliary rotor 100 according to Embodiment 2, when the first auxiliary rotor 110 and the second auxiliary rotor 120 are positioned at both ends of the rotor 150 in the direction of the rotor axis L150, the magnetic pole direction of the first auxiliary magnet 112A and the magnetic pole direction of the first auxiliary magnet 122A are directed toward the rotor 150 in the direction along the rotor axis L150. Also, when viewed along the rotor axis L150, the first direction C10a and the first second direction C20a are equal in direction. Furthermore, the combination of each first auxiliary magnet 112 positioned along the rotor axis L150 and the corresponding second auxiliary magnet 122 is one of the following: the first auxiliary magnet 112A and the first auxiliary magnet 122A; the second auxiliary magnet 112B and the second auxiliary magnet 122B; the third first auxiliary magnet 112C and the third second auxiliary magnet 122C; and the fourth first auxiliary magnet 112D and the fourth second auxiliary magnet 122D. As a result, the first auxiliary magnets 112 and the second auxiliary magnets 122, which are arranged periodically in the circumferential direction, are arranged symmetrically with respect to each other. Therefore, the regular arrangement of the first auxiliary magnets 112 and the second auxiliary magnets 122 results in a symmetrical magnetic flux flow. Consequently, an auxiliary rotor 100 can be provided that allows for easier setting of the magnetic flux flow compared to the existing rotor 150. Furthermore, a balanced magnetic flux can be generated at both ends in the direction along the rotor axis L150. Thus, even with the auxiliary rotor 100 installed, the stability of operation can be ensured in the rotor 150.

[0149] In the auxiliary rotor 100 according to Embodiment 2, the rotor 150 has a plurality of rotor magnets 153 arranged in the circumferential direction around the rotor axis L150, and when the first auxiliary rotor 110 and the second auxiliary rotor 120 are positioned at both ends of the rotor 150 in the direction of the rotor axis L150, at least one of the first auxiliary magnets 112, the corresponding second auxiliary magnet 122, and the corresponding rotor magnet 153, which are arranged in a line along the rotor axis L150, are arranged in a Halbach arrangement. As a result, by installing the first auxiliary rotor 110 and the second auxiliary rotor 120 on the existing rotor 150, a Halbach arrangement can be formed including the first auxiliary magnet 112 and the second auxiliary magnet 122 in addition to the rotor magnets 153, thereby increasing the magnetic flux. Therefore, by using the auxiliary rotor 100, it is possible to increase the output of the motor and reduce the heat generated by the motor. Furthermore, since the arrangement of the existing rotor magnets 153, along with the added first auxiliary magnets 112 and second auxiliary magnets 122, forms a Halbach arrangement, the magnetic flux can be increased. Therefore, the output of the motor equipped with the auxiliary rotor 100 can be increased, and heat generation can be reduced. [Explanation of Symbols]

[0150] 1 Motor, 2 Housing, 3 Rotor shaft, 4 Stator, 5 Rotor, 10 Rotor main section, 11 Main rotor core, 12 Main magnets, 12A First main magnet, 12B Second main magnet, 12C Third main magnet, 12D Fourth main magnet, 20 First rotor end, 21 First rotor core, 22 First magnet, 22A First first magnet, 22B Second first magnet, 22C Third first magnet, 22D Fourth first magnet, 30 Second rotor end, 31 Second rotor core, 32 Second magnet, 32A First second magnet, 32B Second second magnet, 32C Third second magnet, 32D Fourth second magnet, 45 Stator core, 50 Coil, 90, 91 Rotor, 100 Auxiliary rotor, 110 First auxiliary rotor, 111 First auxiliary core, 112 First auxiliary magnet, 112A First auxiliary magnet, 112B Second first auxiliary magnet, 112C Third first auxiliary magnet, 112D Fourth first auxiliary magnet, 120 Second auxiliary rotor, 121 Second auxiliary core, 122 Second auxiliary magnet, 122A First second auxiliary magnet, 122B Second second auxiliary magnet, 122C Third second auxiliary magnet, 122D Fourth second auxiliary magnet, 150 Rotor, 151 Rotating axis, 152 Rotor core, 153 Rotor magnet, C Circumference, Ca First direction, Cb Second direction, C10 First circumference, C10a First first direction, C10b Second first direction, C20 Second circumference, C20a First second direction, C20b Second second direction, L Central axis, L10 First axis, L20 Second axis, L150 Rotor axis, S Space.

Claims

1. A rotor main section (10) that rotates about a central axis (L), A first rotor end (20) is positioned at one end of the rotor main portion (10) in the direction along the central axis (L), A second rotor end (30) is positioned at the end of the rotor main portion (10) opposite to one end in the direction along the central axis (L), Equipped with, The rotor main part (10) has a plurality of main magnets (12), The first rotor end (20) has a plurality of first magnets (22), The second rotor end (30) has a plurality of second magnets (32), When viewed along the central axis (L), each of the main magnets (12), each of the first magnets (22), and each of the second magnets (32) are arranged in a line along the circumference (C) of a circle whose center lies on the central axis (L). Each of the first magnets (22) and each of the second magnets (32) are arranged in a Halbach arrangement along the corresponding circumference (C), When viewed from a direction perpendicular to the central axis (L), each of the main magnets (12), the corresponding first magnet (22), and the corresponding second magnet (32) are arranged in a line along the central axis (L). The first magnets (22), the second magnets (32), and the main magnets (12) are arranged in a line corresponding to each other along the central axis (L), and at least one of the first magnets (22), the corresponding second magnets (32), and the corresponding main magnets (12) are arranged in a Halbach arrangement along the central axis (L). When viewed from a direction perpendicular to the central axis (L), the rotor main portion (10) faces the stator core (45), and at least a portion of the first rotor end (20) and at least a portion of the second rotor end (30) do not face the stator core (45). Rotor (5).

2. Each of the main magnets (12) is arranged in a Halbach arrangement along the circumference (C). The rotor (5) according to claim 1.

3. Viewed along the central axis (L), one direction in the circumferential direction of the circumference (C) is called the first direction (Ca), and the other direction in the circumferential direction of the circumference (C) opposite to the first direction (Ca) is called the second direction (Cb). When viewed along the central axis (L), each of the first magnets (22) is one of the following: a first magnet (22A) having a magnetic pole direction toward the rotor main part (10) along the central axis (L); a second magnet (22B) having a magnetic pole direction opposite to the magnetic pole direction of the first magnet (22A); a third magnet (22C) having a magnetic pole direction equal to the tangential direction of the circumference (C) along the first direction (Ca); and a fourth magnet (22D) having a magnetic pole direction equal to the tangential direction of the circumference (C) along the second direction (Cb). Each of the first magnets (22) is arranged along the circumference (C) in the order of the first first magnet (22A), the third first magnet (22C), the second first magnet (22B), and the fourth first magnet (22D), and this order is repeated. When viewed along the central axis (L), each of the second magnets (32) is one of the following: a first second magnet (32A) having a magnetic pole direction toward the rotor main part (10) along the central axis (L); a second second magnet (32B) having a magnetic pole direction opposite to the magnetic pole direction of the first second magnet (32A); a third second magnet (32C) having a magnetic pole direction equal to the tangential direction of the circumference (C) along the first direction (Ca); and a fourth second magnet (32D) having a magnetic pole direction equal to the tangential direction of the circumference (C) along the second direction (Cb). The combination of each first magnet (22) and the corresponding second magnet (32) arranged along the central axis (L) is one of the following: the first first magnet (22A) and the first second magnet (32A); the second first magnet (22B) and the second second magnet (32B); the third first magnet (22C) and the third second magnet (32C); and the fourth first magnet (22D) and the fourth second magnet (32D). The rotor (5) according to claim 1 or claim 2.

4. When viewed along the aforementioned central axis (L), Each of the main magnets (12) is one of the following: a first main magnet (12A) having a magnetic pole direction away from the central axis (L); a second main magnet (12B) having a magnetic pole direction toward the central axis (L); a third main magnet (12C) having a magnetic pole direction equal to the tangential direction of the circumference (C) along the first direction (Ca); and a fourth main magnet (12D) having a magnetic pole direction equal to the tangential direction of the circumference (C) along the second direction (Cb). Each of the main magnets (12) is arranged along the circumference (C) in the order of the first main magnet (12A), the third main magnet (12C), the second main magnet (12B), and the fourth main magnet (12D), and this order is repeated. The rotor (5) according to claim 3.

5. The combination of each main magnet (12) arranged along the central axis (L), the corresponding first magnet (22), and the corresponding second magnet (32) is one of the following: the combination of the first main magnet (12A), the first first magnet (22A), and the first second magnet (32A); the combination of the second main magnet (12B), the second first magnet (22B), and the second second magnet (32B); the combination of the third main magnet (12C), the third first magnet (22C), and the third second magnet (32C); and the combination of the fourth main magnet (12D), the fourth first magnet (22D), and the fourth second magnet (32D). The rotor (5) according to claim 4.

6. The combination of each main magnet (12) arranged along the central axis (L), the corresponding first magnet (22), and the corresponding second magnet (32) is one of the following: the combination of the fourth main magnet (12D), the first first magnet (22A), and the first second magnet (32A); the combination of the third main magnet (12C), the second first magnet (22B), and the second second magnet (32B); the combination of the second main magnet (12B), the fourth first magnet (22D), and the fourth second magnet (32D); and the combination of the first main magnet (12A), the third first magnet (22C), and the third second magnet (32C). The rotor (5) according to claim 4.

7. Multiple main magnets (12) are arranged in a line along the central axis (L). The first magnets (22), the second magnets (32), and the plurality of main magnets (12) are arranged in a line corresponding to each other along the central axis (L), and at least one of the first magnets (22), the corresponding second magnets (32), and the corresponding plurality of main magnets (12) are arranged in a Halbach arrangement along the central axis (L). The rotor (5) according to claim 1.

8. A rotor (5) according to any one of claims 1, 2, and 7, A stator (4) having a stator core (45), A motor (1) is provided.

9. It comprises a first auxiliary rotor (110) with the first axis (L10) as its central axis, and a second auxiliary rotor (120) with the second axis (L20) as its central axis. The first auxiliary rotor (110) has a plurality of first auxiliary magnets (112), The second auxiliary rotor (120) has a plurality of second auxiliary magnets (122), When viewed along the first axis (L10), each of the first auxiliary magnets (112) is arranged in a line along the first circumference (C10) of a circle centered on the first axis (L10). When viewed along the second axis (L20), each of the second auxiliary magnets (122) is arranged in a line along the second circumference (C20) of a circle centered on the second axis (L20). Each of the first auxiliary magnets (112) and each of the second auxiliary magnets (122) are arranged in a Halbach arrangement along the corresponding first circumference (C10) or second circumference (C20). The first auxiliary rotor (110) and the second auxiliary rotor (120) can be arranged on a rotor (150) having a rotor axis (L150). The first auxiliary rotor (110) and the second auxiliary rotor (120) can be arranged at both ends of the rotor core (152) of the rotor (150) in the direction along the rotor axis (L150). Auxiliary rotor (100).

10. Viewed along the first axis (L10), one direction in the circumferential direction of the first circumference (C10) is called the first first direction (C10a), and the other direction in the circumferential direction of the first circumference (C10) opposite to the first first direction (C10a) is called the second first direction (C10b). When viewed along the first axis (L10), each of the first auxiliary magnets (112) is one of the following: a first auxiliary magnet (112A) having a magnetic pole direction toward one direction along the first axis (L10); a second auxiliary magnet (112B) having a magnetic pole direction toward the opposite direction to the magnetic pole direction of the first auxiliary magnet (112A); a third auxiliary magnet (112C) having a magnetic pole direction equal to the tangential direction of the first circumference (C10) along the first direction (C10a); and a fourth auxiliary magnet (112D) having a magnetic pole direction equal to the tangential direction of the first circumference (C10) along the second direction (C10b). Each of the first auxiliary magnets (112) is arranged along the first circumference (C10) in the order of the first auxiliary magnet (112A), the third auxiliary magnet (112C), the second auxiliary magnet (112B), and the fourth auxiliary magnet (112D), and this order is repeated. When viewed along the second axis (L20), one direction in the circumferential direction of the second circumference (C20) is called the first second direction (C20a), and the other direction in the circumferential direction of the second circumference (C20) opposite to the first second direction (C20a) is called the second second direction (C20b). When viewed along the second axis (L20), each of the second auxiliary magnets (122) is one of the following: a first auxiliary magnet (122A) having a magnetic pole direction pointing in one direction along the second axis (L20); a second auxiliary magnet (122B) having a magnetic pole direction pointing in the opposite direction to the magnetic pole direction of the first auxiliary magnet (122A); a third auxiliary magnet (122C) having a magnetic pole direction equal to the tangential direction of the second circumference (C20) along the first second direction (C20a); and a fourth auxiliary magnet (122D) having a magnetic pole direction equal to the tangential direction of the second circumference (C20) along the second second direction (C20b). Each of the second auxiliary magnets (122) is arranged along the second circumference (C20) in the order of the first second auxiliary magnet (122A), the third second auxiliary magnet (122C), the second second auxiliary magnet (122B), and the fourth second auxiliary magnet (122D), and this order is repeated. The auxiliary rotor (100) according to claim 9.

11. When the first auxiliary rotor (110) and the second auxiliary rotor (120) are positioned at both ends of the rotor (150) in the direction of the rotor axis (L150), The magnetic pole directions of the first auxiliary magnet (112A) and the magnetic pole directions of the first auxiliary magnet (122A) are aligned with the rotor axis (L150) and are directed toward the rotor (150) toward each other. When viewed along the rotor axis (L150), the first direction (C10a) and the first second direction (C20a) are equal in direction to each other. The combination of each of the first auxiliary magnets (112) arranged along the rotor axis (L150) and the corresponding second auxiliary magnet (122) is one of the following: the first auxiliary magnet (112A) and the first second auxiliary magnet (122A); the second first auxiliary magnet (112B) and the second second auxiliary magnet (122B); the third first auxiliary magnet (112C) and the third second auxiliary magnet (122C); and the fourth first auxiliary magnet (112D) and the fourth second auxiliary magnet (122D). The auxiliary rotor (100) according to claim 10.

12. When the rotor (150) has a plurality of rotor magnets (153) arranged in the circumferential direction around the rotor axis (L150), and the first auxiliary rotor (110) and the second auxiliary rotor (120) are positioned at both ends of the rotor (150) in the direction of the rotor axis (L150), Each of the first auxiliary magnets (112), the corresponding second auxiliary magnet (122), and the corresponding rotor magnet (153) arranged along the rotor axis (L150) are arranged in a Halbach arrangement. The auxiliary rotor (100) according to claim 11.

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