Rotor and motor

Abstract

The present invention provides a rotor and motor equipped with a rotor having multiple rotor cores arranged in the axial direction, which are less prone to deterioration of motor characteristics and can suppress an increase in the number of parts. [Solution] The motor 1 comprises a rotor 10 and a stator 20. The rotor 10 of the motor 1 comprises a first rotor core 100A having a plurality of first frames 109A arranged in the circumferential direction, a second rotor core 100B having a plurality of second frames 109B arranged in the circumferential direction, and a plurality of magnets 130. In the axial direction X, the magnets 130 are housed in the first frames 109A and the second frames 109B, with a portion of the first frame 109A or a portion of the second frame 109B being separated.

Description

Technical Field

[0001] The present invention relates to a rotor and a motor, and more particularly, to a rotor and a motor including the rotor.

Background Art

[0002] Conventionally, a rotor having a rotor core in which magnet mounting hole portions for mounting permanent magnets are formed on the outside, and a motor including the rotor are known (see, for example, Patent Document 1). Further, Patent Document 1 describes a motor including a rotor in which ends of two rotor cores are connected to each other and attached to a common rotating shaft.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the rotor described in Patent Document 1, as described above, since the magnet mounting hole portions are formed on the outside of the rotor core, a magnetic flux loop is formed in a portion close to the stator in the radial direction. Therefore, due to this magnetic flux loop, the magnetic flux magnetically acting between the stator and the rotor decreases, and as a result, the characteristics of the motor such as the rotational speed of the motor (hereinafter referred to as "motor characteristics") may deteriorate. Further, when the ends of the two rotor cores are connected to each other and attached to a common rotating shaft, in each of the two rotor cores, the magnetic flux magnetically acting between the stator and the rotor decreases, so that the motor characteristics may further deteriorate.

[0005] Furthermore, in the motor described in Patent Document 1, magnets are attached to each magnet mounting hole in each of the rotor cores, which are mounted on a common rotating shaft by connecting the ends of the two rotor cores. As a result, the motor described in Patent Document 1 has an increased number of magnets and therefore an increased number of parts.

[0006] Therefore, the present invention aims to address, as an example, the suppression of a decrease in motor characteristics and the suppression of an increase in the number of parts. [Means for solving the problem]

[0007] (1) The rotor according to the present invention comprises a first rotor core having a plurality of first frames arranged in the circumferential direction, a second rotor core having a plurality of second frames arranged in the circumferential direction, and a plurality of magnets, wherein in the axial direction, the magnets are housed in the first frame and the second frame, and a part of the first frame or a part of the second frame is separated.

[0008] (2) In the rotor relating to (1), parts of the first frame and the second frame may be separated.

[0009] (3) In the rotor relating to (1) or (2), a part of the first frame may be offset from a part of the second frame in the circumferential direction.

[0010] (4): The motor according to the present invention comprises a rotor (one of (1) to (3)) and a stator. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view showing a motor according to an embodiment of the present invention. [Figure 2] This is a cross-sectional view of the motor shown in Figure 1, along the axial direction. [Figure 3] This is a cross-sectional view of the motor shown in Figure 1 along line AA shown in Figure 2. [Figure 4] This is a cross-sectional view of the motor shown in Figure 1 along the line BB shown in Figure 2. [Figure 5] Figure 1 is a perspective view showing the rotor of the motor. [Figure 6] This is a perspective view of the rotor shown in Figure 5, with the line of sight directed in the direction of arrow C shown in Figure 5. [Figure 7] This is a perspective view of the rotor shown in Figure 5, with the line of sight directed in the direction of arrow D shown in Figure 5. [Figure 8] This is a cross-sectional view along the axial direction of the rotor shown in Figure 5, at the position on the EE line shown in Figures 6 and 7. [Modes for carrying out the invention]

[0012] The following examples illustrate embodiments of the rotor and motor according to the present invention, along with the accompanying drawings. The embodiments illustrated below are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. The present invention can be modified and improved from the following embodiments without departing from its spirit. In addition, in the accompanying drawings, the dimensions of each component may be exaggerated or reduced, or hatching may be omitted, in order to facilitate understanding.

[0013] Figure 1 is a perspective view showing the motor in this embodiment. As shown in Figure 1, the motor 1 has a columnar shape extending in direction X. In this embodiment, the motor 1 has a cylindrical shape centered on axis CA, which extends in direction X. Hereinafter, direction X will be referred to as "axial direction X". The direction passing through axis CA and perpendicular to axial direction X will be referred to as the "radial direction". Furthermore, in the radial direction, the side relatively closer to axis CA may be referred to as "inside", etc., and the side relatively farther from axis CA may be referred to as "outside", etc., and the "outside". Also, the circumferential direction of the circle centered on axis CA when viewing the motor 1 with the line of sight directed in axial direction X will be referred to as the "circumferential direction".

[0014] Motor 1 comprises a rotor 10 and a stator 20 located outside the rotor 10. In the radial direction, the stator 20 surrounds the rotor 10. Therefore, motor 1 is configured as a so-called inner rotor type motor. In this embodiment, the rotor 10 and the stator 20 are formed concentrically with respect to the axis CA.

[0015] The stator 20 is formed by connecting a plurality of stator elements (divided cores) 200 in the circumferential direction. Specifically, the ends of two adjacent stator elements 200 in the circumferential direction are connected to form a ring-shaped stator. In this embodiment, the number of plurality of stator elements 200 in the stator 20 is 12, but the number of plurality of stator elements 200 is not particularly limited and may be 10 or 20. Figure 2 is a cross-sectional view of the motor 1 along the axial direction X. As shown in Figures 1 and 2, each of the plurality of stator elements 200 extends in the axial direction X.

[0016] Figure 3 is a cross-sectional view along line AA shown in Figure 2. Figure 4 is a cross-sectional view along line BB shown in Figure 2. As shown in Figures 3 and 4, each of the multiple stator elements 200 includes a stator core 201, an insulator 202, and a coil 203.

[0017] The stator core 201 is formed of a magnetic material such as iron, for example, and in this embodiment, it has a generally symmetric shape when viewed with the line of sight directed in the axial direction X. The stator core 201 includes an outer arc-shaped (curved-shaped) outer peripheral portion 210, an extending portion (spoke) 211 that extends radially inward from the outer peripheral portion 210, and a portion 212 connected to the inner end of the extending portion 211. This portion 212 extends in one side and the other side in the circumferential direction with respect to the extending portion 211, and forms a magnetic pole portion facing the rotor 10 in the radial direction. Hereinafter, the portion 212 is referred to as "salient pole 212". A so-called tooth T is constituted by the extending portion 211 and the salient pole 212. In this embodiment, in the circumferential direction, the length of the salient pole 212 is shorter than the length of the outer peripheral portion 210, but it is not limited to this, and it may be the same or longer.

[0018] The insulator 202 includes a (inner) side portion that covers the inner surface of the outer peripheral portion 210 of the stator core 201, a cylinder that covers the extending portion 211, and a (outer) side portion that covers the outer surface of the salient pole 212, and surrounds a part of the stator core 201. That is, the inner peripheral surface 201SA and the outer peripheral surface 201SB of the stator core 201 are exposed from the insulator 202. The coil 203 is wound around the extending portion 211 of the stator core 201 via the insulator 202 and is insulated from the stator core 201.

[0019] The stator 20 is formed by connecting stator elements 200 having such a configuration along the circumferential direction. The outer peripheral surface of the stator 20 is formed by the outer peripheral surfaces 201SB of each of the plurality of stator elements 200. Further, if necessary, the motor 1 may include a housing 1H (frame) that houses the stator 20. In FIG. 1, for the sake of convenience, the general appearance of the housing 1H is shown by a dashed line, and the appearance of the housing 1H is not limited to that shown by the dashed line. When the motor 1 does not include the housing 1H, the outer peripheral surface 1A of the motor 1 may be formed by the plurality of outer peripheral surfaces 201SB. On the other hand, the inner peripheral surface 220 of the stator 20 is formed by the inner peripheral surfaces 201SA of each of the plurality of stator elements 200.

[0020] In the present embodiment, an example in which the stator 20 is formed by connecting the stator elements 200 in the circumferential direction has been described, but the stator may be formed using an annular stator core (that is, one stator core).

[0021] FIG. 5 is a perspective view showing the rotor 10. FIG. 6 is a perspective view of the rotor 10 seen with the line of sight directed in the direction of arrow C shown in FIG. 5 (the direction from one side to the other side in the axial direction X). FIG. 7 is a perspective view of the rotor 10 seen with the line of sight directed in the direction of arrow D shown in FIG. 5 (the direction from the other side to the one side in the axial direction X). As shown in FIGS. 5 to 7, the rotor 10 includes a rotor core 150 and a plurality of magnets 130. In FIGS. 6 and 7, for the sake of explanation, the illustration of one of the plurality of magnets 130 included in the rotor 10 is omitted.

[0022] The rotor core 150 includes a plurality (two in this embodiment) of rotor cores 100 having similar configurations. Specifically, the rotor core 150 includes a rotor core 100 located on one side in the axial direction X (hereinafter, for convenience, the term "upper side," etc., may be used to refer to it) (hereinafter referred to as the "first rotor core 100A") and a rotor core 100 located on the other side in the axial direction X (hereinafter, for convenience, the term "lower side," etc., may be used to refer to it) (hereinafter referred to as the "second rotor core 100B"). The first rotor core 100A and the second rotor core 100B are connected and arranged in the axial direction X with axis CA concentric.

[0023] Here, the first rotor core 100A and the second rotor core 100B have the same configuration as described above. Therefore, the components of the second rotor core 100B are denoted by the same reference numerals as those of the first rotor core 100A, and the description of the components of the second rotor core 100B is omitted unless necessary.

[0024] As shown in Figures 5 and 6, the first rotor core 100A has a cylindrical shape (in this embodiment, cylindrical) and is made of a magnetic material such as iron. As shown in Figure 2, in the axial direction X, the length of the first rotor core 100A may be about half the length of the stator core 201 of the stator element 200. Returning to Figures 5 and 6, when viewed along the axial direction X, the first rotor core 100A includes a first annular portion 101, a plurality of spokes 102, a second annular portion 103, a plurality of protrusions 104, and a plurality of outer peripheral portions 105.

[0025] The first annular portion 101 is formed in an annular shape (circular in this embodiment) and has a cylindrical inner circumferential surface 100SB. This inner circumferential surface 100SB is the inner circumferential surface of the first rotor core 100A and forms a hole 100PH that penetrates the inside of the first rotor core 100A (the center in the radial direction in this embodiment) in the axial direction X. As shown in Figure 2, a rotating shaft 30 with axis CA as its central axis is inserted through this hole 100PH, and the first rotor core 100A is fixed to the rotating shaft 30. In Figure 2, for convenience, the rotating shaft 30 is schematically shown with a dashed line. Also, in drawings other than Figure 2, for convenience, the illustration of the rotating shaft 30 is omitted.

[0026] As shown in Figures 5 and 6, the multiple spokes 102 extend radially outward from the outer surface of the first annular portion 101. The second annular portion 103 is formed in an annular shape (approximately circular in this embodiment). The outer ends of each of the multiple spokes 102 are connected to the second annular portion 103. In the illustrated example, the number of multiple spokes 102 is 14, but this is not particularly limited.

[0027] The first rotor core 100A has multiple holes 108 formed along its circumference, penetrating the first rotor core 100A in the axial direction X, formed by the first annular portion 101, the multiple spokes 102, and the second annular portion 103. These holes 108 can be used to reduce the weight of the first rotor core 100A. In this embodiment, the number of holes 108 is the same as the number of magnets 130 (14 in the illustrated example), and the multiple holes 108 and the multiple magnets 130 are arranged radially in a one-to-one correspondence. The number of holes 108 is not particularly limited; for example, it does not have to be the same as the number of magnets 130. Also, the holes 108 and the magnets 130 do not have to be arranged radially.

[0028] Multiple protrusions 104 project outward from the outer circumferential surface of the second annular portion 103. The number of protrusions 104 is not particularly limited, but in this embodiment, it is 14, the same number as the spokes 102. In this embodiment, multiple protrusions 104 are provided in one-to-one correspondence with multiple spokes 102. Specifically, each protrusion 104 is provided such that its inner end 104A (hereinafter referred to as the "root portion 104A") is located on a straight line extending in the direction in which the spoke 102 corresponding to the protrusion 104 extends. The root portion 104A of the protrusion 104 is the part where the protrusion 104 connects to the second annular portion 103.

[0029] Furthermore, each protrusion 104 does not necessarily have to be positioned such that its root portion 104A is located on a straight line extending in the direction in which the spoke 102 corresponding to the protrusion 104 extends. In other words, the root portion 104A may be located at a position offset from the straight line extending in the direction in which the corresponding spoke 102 extends.

[0030] The outer peripheral portion 105 is connected to the end of the protruding portion 104 that is opposite (outside) to the root portion 104A (inside). The outer surfaces 100SA of each of the multiple outer peripheral portions 105 form the outer peripheral surface 111 of the first rotor core 100A. As shown in Figures 3 and 4, this outer peripheral surface 111 faces the inner peripheral surface 220 of the stator 20 in the radial direction via an air gap G.

[0031] Furthermore, as shown in Figure 6, the outer periphery 105 extends clockwise in the circumferential direction when viewed from the side of arrow C (when the line of sight is directed from the top to the bottom). Also, when viewed from the side of arrow C, the clockwise side of the outer periphery 105 terminates. That is, the outer periphery 105 includes a termination (end) portion 105E. Therefore, when viewed from the side of arrow C, the termination portion 105E of the outer periphery 105 that connects to any protrusion 104 and the root portion 104A of the protrusion 104 adjacent to that protrusion 104 in the clockwise direction in the circumferential direction are separated radially, and a gap (hereinafter referred to as "separation portion 106") is formed between these termination portion 105E and root portion 104A.

[0032] Furthermore, in this embodiment, when viewed with the line of sight in the axial direction X, the radial thickness of the outer periphery 105 is not constant along the circumferential direction. In other words, the outer periphery 105 includes a thickened portion 105A having a portion with maximum thickness. The position of the thickened portion 105A in the circumferential direction is not particularly limited, but in this embodiment, it is formed in the center of the outer periphery 105 in the circumferential direction.

[0033] In this embodiment, a roughly rectangular space 107 is formed when viewed from the perspective of the axial direction X by an arbitrary outer peripheral portion 105 from among the plurality of outer peripheral portions 105, a protruding portion 104 connected to the arbitrary outer peripheral portion 105, and a portion of the second annular portion 103 that radially faces the arbitrary outer peripheral portion 105 (hereinafter referred to as the "facing portion 103A"). In other words, the outer peripheral portion 105, the protruding portion 104, and the facing portion 103A constitute a frame 109 that defines the space 107. The number of frames 109 and spaces 107 is the same as the number of protruding portions 104 and the number of outer peripheral portions 105, which in this embodiment is 14.

[0034] In addition, the frame 109 of the first rotor core 100A may be referred to as the "first frame 109A," and the frame 109 of the second rotor core 100B may be referred to as the "second frame 109B." In the first rotor core 100A, multiple first frames 109A are arranged in the circumferential direction, and in the second rotor core 100B, multiple second frames 109B are arranged in the circumferential direction.

[0035] The space 107 inside the frame 109 is an open space with an upper end and a lower end, and extends along the entire length of the first rotor core 100A in the axial direction X. As shown in Figure 6, when viewed from the direction of arrow C, the clockwise end of the space 107 of the first frame 109A is the dividing portion 106. On the other hand, as shown in Figure 7, when viewed from the direction of arrow D, the clockwise end of the space 107 of the second frame 109B is the dividing portion 106. Therefore, in this embodiment, a part of each of the first frame 109A and the second frame 109B is divided. A part of a single magnet 130 is placed in each of the spaces 107 of the first frame 109A and the space 107 of the second frame 109B. Specifically, the upper half of the single magnet 130 may be housed in the space 107 of the first frame 109A, and the lower half of the single magnet 130 may be housed in the space 107 of the second frame 109B.

[0036] In the rotor core 150, the second rotor core 100B is a stator core having the same configuration as the first rotor core 100A, but inverted in the axial direction X. Therefore, as described above and as shown in Figure 7, when the rotor 10 is viewed from the direction of arrow D, the clockwise end of the space 107 formed by the second frame 109B is the divided portion 106. That is, the divided portion 106 of the first frame 109A of the first rotor core 100A and the divided portion 106 of the second frame 109B of the second rotor core 100B are formed on opposite sides in the circumferential direction when viewed from the same side in the axial direction X.

[0037] As shown in Figures 5 to 7, the rotor core 150 of this embodiment is constructed by aligning the central axes of the first rotor core 100A and the second rotor core 100B with axis CA, and then aligning and connecting the first rotor core 100A and the second rotor core 100B in the axial direction with a relative offset in the circumferential direction. The length RD of this circumferential offset may be, for example, substantially equal to the length of the root portion 104A of the protrusion 104 in the circumferential direction. With this configuration, in the rotor core 150, in each pair of first frames 109A and second frames 109B (hereinafter referred to as "frame pair 190") that are in contact with each other in the axial direction X, the dividing portion 106 of the second frame 109B is positioned below the protrusion 104 of the first frame 109A, and the protrusion 104 of the second frame 109B is positioned below the dividing portion 106 of the first frame 109A.

[0038] Incidentally, when neither the first frame 109A nor the second frame 109B has a dividing portion 106, if the central axes of the first rotor core 100A and the second rotor core 100B are aligned with axis CA, and then the positions of the first rotor core 100A and the second rotor core 100B are relatively shifted in the circumferential direction and they are connected in the axial direction, then the protruding portion 104 of the second rotor core 100B is located below the protruding portion 104 of the first rotor core 100A.

[0039] Here, Figure 8 is a cross-sectional view of the rotor 10 along the axial direction at the position on the EE line shown in Figures 6 and 7. As described above and as shown in Figure 8, in the rotor 10, the positions of the first rotor core 100A and the second rotor core 100B are relatively offset in the circumferential direction, so that in each of the multiple frame pairs 190, the dividing portion 106 of the second frame 109B is positioned below the protruding portion 104 of the first frame 109A. Therefore, one side 130E in the circumferential direction of the magnet 130 inserted into the first frame 109A of the first rotor core 100A can enter the second frame 109B of the second rotor core 100B without interference from the protruding portion 104 of the second rotor core 100B. In other words, the side portion 130E of the magnet 130 inserted into the first frame 109A of the first rotor core 100A passes through the dividing portion 106 of the second rotor core 100B along the axial direction X, so that the upper portion 130a of one magnet 130 is housed in the first frame 109A of the frame pair 190, and the lower portion 130b of the same magnet 130 is housed in the second frame 109B of the frame pair 190.

[0040] Furthermore, by connecting the first rotor core 100A and the second rotor core 100B with their positions in the circumferential direction offset relative to each other while centered on axis CA, the respective thickened portions 105A, 105A of the first frame 109A and the second frame 109B are positioned offset in the circumferential direction in each of the multiple frame pairs 190.

[0041] In the rotor core 150, as shown in Figures 5 to 7, the inner circumferential surface 110 of the rotor core 150 is formed by the inner circumferential surface 100SB of the first rotor core 100A and the inner circumferential surface 100SB of the second rotor core 100B. Then, as shown in Figure 2, this inner circumferential surface 110 forms a hole 10PH of the rotor core 150, which is formed by the communication of the hole 100PH of the first rotor core 100A and the hole 100PH of the second rotor core 100B. The rotating shaft 30 is inserted into this hole 10PH, and the rotor core 150 is fixed to the rotating shaft 30. Therefore, the rotor 10 can rotate together with the rotating shaft 30.

[0042] In a motor 1 comprising such a rotor 10 and stator 20, when current is supplied to the coil 203 of the stator 20, a magnetic interaction occurs between the outer circumferential surface 111 of the rotor 10 and the inner circumferential surface 220 of the stator 20, as shown in Figures 3 and 4, causing the rotor 10 to rotate around axis CA relative to the stator 20.

[0043] As described above, the motor 1 of this embodiment comprises a rotor 10 and a stator 20. The rotor 10 of the motor 1 comprises a first rotor core 100A having a plurality of first frames 109A arranged in the circumferential direction, a second rotor core 100B having a plurality of second frames 109B arranged in the circumferential direction, and a plurality of magnets 130. In the axial direction X, the magnets 130 are housed in the first frames 109A and the second frames 109B, with a portion of the first frame 109A or a portion of the second frame 109B being separated.

[0044] With such a rotor 10 and motor 1 equipped with the rotor 10, a portion of the second frame 109B, which is one of the first frame 109A and the second frame 109B, is separated. As a result, the generation of magnetic flux loops on the outer circumference of the second rotor core 100B is suppressed, and consequently, the amount of magnetic flux that magnetically interacts with the stator 20 is suppressed. Therefore, according to this embodiment, in a motor in which multiple rotor cores are arranged in the axial direction X, the decrease in motor characteristics such as the rotational speed of the motor is suppressed.

[0045] Furthermore, with the rotor 10, a portion of the second frame 109B, which is one of the first frame 109A and the second frame 109B, is separated, forming a separated portion 160 in the second frame 109B. This makes it possible to insert one magnet 130 across the first frame 109A of the first rotor core 100A and the second frame 109B of the second rotor core 100B, and to accommodate one magnet 130 in both the first frame 109A and the second frame 109B. Therefore, with the rotor 10, there is no need to separately prepare magnets to be attached to the first rotor core 100A and magnets to be attached to the second rotor core 100B, reducing the number of magnets and suppressing an increase in the number of parts. In addition, with the rotor 10, the process of attaching magnets to the first rotor core 100A and the process of attaching magnets to the second rotor core 100B can be performed in a single process, thus simplifying the manufacturing of motors in which multiple rotor cores are arranged in the axial direction X.

[0046] Furthermore, in the rotor 10 of this embodiment, as described above, not only the second frame 109B, which is one of the first frame 109A and the second frame 109B, but also a part of the other frame, the first frame 109A, is divided. Therefore, the generation of magnetic flux loops on the outer circumference of the first rotor core 100A is suppressed, and the decrease in the amount of magnetic flux that magnetically interacts with the stator 20 is further suppressed. Accordingly, according to this embodiment, the deterioration of motor characteristics is further suppressed in a motor in which multiple rotor cores are arranged in the axial direction X.

[0047] Furthermore, in the rotor 10 of this embodiment, as described above, not only the second frame 109B, which is one of the first frame 109A and the second frame 109B, but also a part of the other frame, the first frame 109A, is divided. Therefore, whether inserting a single magnet 130 from the top to the bottom or from the bottom to the top, it is easy to insert one magnet 130 into the first frame 109A and the second frame 109B of the frame pair 190.

[0048] In the above embodiment, for the sake of explanation, the upper rotor core 100 is designated as the first rotor core 100A, the frame 109 of the upper rotor core 100 is designated as the first frame 109A, the lower rotor core 100 is designated as the second rotor core 100B, and the frame 109 of the lower rotor core 100 is designated as the second frame 109B. However, it is also acceptable to designate the upper rotor core 100 as the second rotor core 100B, the frame 109 of the upper rotor core 100 as the second frame 109B, the lower rotor core 100 as the first rotor core 100A, and the frame 109 of the lower rotor core 100 as the first frame 109A.

[0049] Furthermore, in this embodiment, the rotor 10 has a circumferential misalignment between the first rotor core 100A and the second rotor core 100B, with a portion of the first frame 109A being misaligned with a portion of the second frame 109B. That is, in the rotor 10, the position of the first frame 109A through which the magnetic flux interacting magnetically with the stator 20 in the first rotor core 100A passes, and the position of the second frame 109B through which the magnetic flux interacting magnetically with the stator 20 in the second rotor core 100B passes, are misaligned in the circumferential direction. With this configuration, the phase of the cogging torque acting on the first rotor core 100A when the motor 1 is driven is misaligned with the phase of the cogging torque acting on the second rotor core 100B when the motor 1 is driven, thus reducing the total amount of cogging torque acting on the rotor core 150. Therefore, the rotor 10 can suppress cogging torque when the motor is driven.

[0050] Furthermore, in the rotor 10 of this embodiment, since a thickened portion 105A is formed on the outer circumference 105 of the frame 109, the magnetic flux that magnetically interacts with the stator 20 tends to concentrate in the thickened portion 105A. In addition, in the rotor 10 of this embodiment, since the first rotor core 100A and the second rotor core 100B are offset in the circumferential direction, the position of the thickened portion 105A of the first rotor core 100A and the position of the thickened portion 105A of the second rotor core 100B are offset in the circumferential direction. In this way, because the thickened portions 105A, 105A, where magnetic flux tends to concentrate, are offset in the circumferential direction, the phase (rotation angle) at which the cogging torque acting on the first rotor core 100A peaks and the phase (rotation angle) at which the cogging torque acting on the second rotor core 100B peaks tend to be offset. Therefore, in the rotor 10, the total amount of cogging torque acting on the rotor core 150 can be further reduced.

[0051] Furthermore, it is not necessary to form a thickened portion 105A on the outer circumference 105. Even in such a case, if a part of the first frame 109A is misaligned with a part of the second frame 109B, the total amount of cogging torque acting on the rotor core 150 can be reduced.

[0052] Although the present invention has been described above using the above-described embodiments as examples, the present invention is not limited thereto.

[0053] For example, in the above embodiment, an example was described in which the first rotor core 100A and the second rotor core 100B are misaligned in the circumferential direction (i.e., a part of the first frame 109A is misaligned with a part of the second frame 109B). However, it is not necessary for the first rotor core 100A and the second rotor core 100B to be misaligned in the circumferential direction (modification 1).

[0054] Even with this modified version 1, since parts of the first frame 109A and the second frame 109B are separated, the occurrence of magnetic flux loops on the outer circumference of the first rotor core 100A and the outer circumference of the second rotor core 100B is suppressed. Therefore, in a motor in which multiple rotor cores are arranged in the axial direction X, a deterioration in motor characteristics is suppressed. Furthermore, with this modified version 1, since parts of the first frame 109A and the second frame 109B are separated, it is easy to insert one magnet 130 across the first frame 109A of the first rotor core 100A and the second frame 109B of the second rotor core 100B, and it is easy to house one magnet 130 in the first frame 109A and the second frame 109B. Therefore, even with this modified version 1, in a motor in which multiple rotor cores are arranged in the axial direction X, the number of magnets can be reduced, suppressing an increase in the number of parts, and the manufacturing process can be simplified.

[0055] Furthermore, in the above-described embodiment, an example was explained in which the upper stator core and the lower stator core have the same configuration in the axial direction X. However, the upper stator core and the lower stator core may have different configurations. For example, in the above-described embodiment, since the upper stator core and the lower stator core have the same configuration in the axial direction X, parts of the first frame 109A and the second frame 109B are separated. However, for example, in the upper stator core, a modified example 2 may be constructed in which protrusions 104 are connected to both ends in the circumferential direction of the outer peripheral portion 105. In this modified example 2, only the second frame of the first and second frames has a configuration in which a part of it is separated.

[0056] In this modified example 2, since the frame (second frame) of one of the stator cores (the upper stator core and the lower stator core) is separated, the generation of magnetic flux loops on the outer circumference of one of the stator cores is suppressed. Therefore, in a motor in which multiple rotor cores are arranged in the axial direction X, the deterioration of motor characteristics is suppressed. Furthermore, according to this modified example 2, since a part of the second frame is separated, it is possible to insert one magnet 130 across the first and second frames of the frame pair, and one magnet 130 can be housed in the first and second frames of the frame pair. Therefore, even with this modified example 2, the number of magnets in a motor in which multiple rotor cores are arranged in the axial direction X can be reduced, and the manufacturing process of the motor can be simplified.

[0057] Those skilled in the art can modify the rotor and motor of the present invention as appropriate in accordance with conventionally known knowledge. Such modifications, insofar as they still possess the configuration of the present invention, are of course included within the scope of the present invention. [Explanation of Symbols]

[0058] 1...Motor, 10...Rotor, 20...Stator, 100A...First rotor core, 100B...Second rotor core, 109A...First frame, 109B...Second frame, 130...Magnet

Claims

1. A first rotor core having multiple first frames arranged in the circumferential direction, A second rotor core having multiple second frames arranged in the circumferential direction, Multiple magnets, Equipped with, In the axial direction, the magnet is housed in the first frame and the second frame. A rotor in which a part of the first frame or a part of the second frame is separated.

2. The rotor according to claim 1, wherein a part of the first frame and a part of the second frame are separated.

3. The rotor according to claim 1 or 2, wherein in the circumferential direction, a part of the first frame is offset from a part of the second frame.

4. A rotor according to any one of claims 1 to 3, stator and, A motor equipped with a motor.

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