Rotor and stator

Abstract

To provide a rotor and a stator, which can cancel torque fluctuation of an iron core piece or a block, and can be easily manufactured.SOLUTION: A rotor 10 includes a rotor core 11 that has an inner rotor type, and is adopted to a magnet embedded type motor, and is formed by rotating and laminating a plurality of rotor side iron core pieces 13. The rotor core 11 includes a plurality of magnet housing holes 14 with an interval in a peripheral direction. In each magnet housing hole 14, a magnet 15 is housed. By a part between each magnet housing hole 14 from the rotor core 11 and an external peripheral surface 11a of the rotor core 11 positioned to an outer peripheral side of each magnet housing hole 14, an objective region 30 is formed. In a plurality of first objective regions 31, a first notch 33 that is different in an arrangement with a second objective regions 41 is provided. Both of each first objective region 31 and each second objective region 41 are overlapped in a shaft direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a rotor and a stator. [Background technology]

[0002] Patent Document 1 describes a stator core constituting an outer rotor type motor. The stator core described in Patent Document 1 is a laminated body formed by laminating a plurality of stator steel plates, and is arranged inside a cylindrical rotor. The stator steel plate has a ring-shaped core back and a plurality of teeth protruding from the core back toward the radial outside of the core back. The stator steel plate also has a first stator steel plate having one recess in the center part of the tip of each tooth, and a second stator steel plate having two recesses in the center part of the tip of each tooth. The first stator steel plate and the second stator steel plate constituting the stator core cause torque fluctuation due to magnetic interaction with the rotor. The shapes and arrangements of the recesses of the first stator steel plate and the second stator steel plate are set so that the above-mentioned torque fluctuations caused by the first stator steel plate and the second stator steel plate cancel each other out. This suppresses the torque fluctuation of the stator core. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-171802 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, the steel plates (hereinafter referred to as core pieces) constituting the laminates of conventional motor cores including the stator core described in Patent Document 1 are formed by a press device. When forming multiple types of core pieces with different shapes and arrangements of recesses, as in the stator core described in Patent Document 1, it is necessary to prepare a punch for pressing the core pieces for each type of core piece. This causes a problem that the manufacturing process of the motor core becomes complicated. [Means for solving the problem]

[0005] A rotor for solving the above problem is an inner rotor type rotor that is applied to a magnet-embedded motor and has a rotor core formed by rotating and stacking a plurality of iron core pieces or a plurality of blocks formed by stacking a plurality of the iron core pieces, the rotor core has a plurality of magnet accommodating holes spaced apart in the circumferential direction of the rotor, and magnets are accommodated in the magnet accommodating holes.When the portion of the rotor core between the magnet accommodating holes and the outer peripheral surface of the rotor core located on the outer side of the magnet accommodating holes is taken as a target area, at least one of the multiple target areas is provided with an irregularly shaped part that has a shape or arrangement different from the other target areas, and the target area of ​​the iron core piece or block that has the irregularly shaped part and the target area of ​​the iron core piece or block that does not have the irregularly shaped part overlap in the axial direction of the rotor.

[0006] According to this configuration, the torque fluctuation due to the magnetic interaction between the stator and the rotor in the multiple target regions differs depending on the presence or absence of the irregular part. Therefore, the target region having the irregular part and the target region not having the irregular part will generate different torque fluctuations. According to the above configuration, the target region having the irregular part among the core pieces or blocks and the target region not having the irregular part among the core pieces or blocks overlap in the axial direction of the rotor. Therefore, by rotating and stacking multiple core pieces or multiple blocks having the same shape, core pieces or blocks having different torque fluctuation characteristics are stacked. This makes it possible for the stacked core pieces or blocks to cancel out the torque fluctuations of the core pieces or blocks. Therefore, the rotor can be manufactured more easily than when multiple types of core pieces having different shapes and arrangements are stacked.

[0007] Moreover, a stator for solving the above problem is an inner rotor type, and is applied to an embedded magnet motor, and has a stator core formed by rotating and stacking a plurality of iron core pieces or a plurality of blocks formed by stacking a plurality of the iron core pieces, the stator core has an annular yoke and a plurality of teeth protruding from the yoke in the radial direction of the yoke, a coil is wound around the teeth, at least one of the plurality of teeth is provided with an irregularly shaped portion having a shape or arrangement different from the other teeth, and the teeth of the iron core pieces or blocks having the irregularly shaped portion and the teeth of the iron core pieces or blocks not having the irregularly shaped portion overlap in the axial direction of the stator.

[0008] According to this configuration, the torque fluctuation due to the magnetic interaction between the stator and the rotor in the multiple teeth differs depending on whether or not there is an irregular part. Therefore, the teeth with the irregular part and the teeth without the irregular part generate different torque fluctuations. According to the above configuration, the teeth with the irregular part among the core pieces or blocks and the teeth without the irregular part among the core pieces or blocks overlap in the axial direction of the stator. Therefore, by rotating and stacking multiple core pieces or multiple blocks having the same shape, the core pieces or blocks having different torque fluctuation characteristics are stacked. This makes it possible for the stacked core pieces or blocks to cancel out the torque fluctuations of the core pieces or blocks. Therefore, the stator can be manufactured more easily than when multiple types of core pieces with different shapes and arrangements are stacked. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of the motor. [Diagram 2] FIG. 2 is a cross-sectional view of the motor centered on the area of ​​interest in FIG. [Diagram 3] FIG. 3 is a graph showing the relationship between torque fluctuation and time for the rotors of this embodiment, Comparative Example 1, and Comparative Example 2. [Figure 4] FIG. 4 is a plan view showing a rotor core of the first modified example. [Diagram 5] FIG. 5 is a plan view showing a rotor core of the second modified example. [Figure 6] FIG. 6 is a cross-sectional view of the motor of the third modified example, centering on the target area. [Figure 7] FIG. 7 is a cross-sectional view of a motor according to a fourth modified example, focusing on a target area. [Figure 8] FIG. 8 is a cross-sectional view of the motor of the fifth modified example, focusing on the target area. [Figure 9] FIG. 9 is a cross-sectional view of a motor according to a sixth modified example, centered on the first and second notches of a stator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, one embodiment of a rotor will be described with reference to FIGS. As shown in Fig. 1, the motor includes a rotor 10 and a stator 20. The motor is an inner rotor type and an embedded magnet type.

[0011] <Rotor 10> 1, rotor 10 includes a cylindrical rotor core 11 having a center hole 12 and a plurality of magnet accommodating holes 14, magnets 15 accommodated in magnet accommodating holes 14, and resin 16 that fills magnet accommodating holes 14 and fixes magnets 15 to rotor core 11. In addition, rotor core 11 is formed with a target area 30.

[0012] In the following description, the axial direction, radial direction, and circumferential direction of rotor core 11 will be simply referred to as the axial direction, radial direction, and circumferential direction, respectively. The rotor core 11 is formed by a laminate in which a plurality of rotor-side core pieces 13 are rotated and stacked. The rotor-side core pieces 13 are made of electromagnetic steel sheets.

[0013] The magnet accommodating holes 14 are provided at intervals from each other in the circumferential direction. The magnet accommodating holes 14 are inclined with respect to the circumferential direction. A pair of magnet accommodating holes 14 adjacent to each other in the circumferential direction are provided so as to have an axis of line symmetry with respect to an imaginary straight line LS extending in the radial direction (see FIG. 2). In other words, the inclination directions of a pair of magnet accommodating holes 14 with respect to the circumferential direction are opposite to each other. In this embodiment, the pair of magnet accommodating holes 14 are inclined so that the closer they are to the imaginary straight line LS in the circumferential direction, the more radially inward they are located. Furthermore, eight pairs of magnet accommodating holes 14 are provided at intervals in the circumferential direction.

[0014] The central hole 12 and each magnet accommodating hole 14 penetrate the rotor core 11 along the axial direction. The magnet 15 has a rectangular parallelepiped shape extending along an axis C.

[0015] (Target Area 30) 1, the target area 30 is formed by a portion of the rotor-side core piece 13 between the magnet accommodating hole 14 and the outer circumferential surface 11a of the rotor-side core piece 13 located on the outer circumferential side of the magnet accommodating hole 14. A plurality of target areas 30 are provided corresponding to each magnet accommodating hole 14 of the rotor-side core piece 13.

[0016] The plurality of target regions 30 include a first target region 31 and a second target region 41 . The first target regions 31 are provided in the multiple target regions 30. In this embodiment, the first target regions 31 are provided corresponding to eight magnet accommodating holes 14 adjacent to each other in the circumferential direction. A pair of first target regions 31 adjacent to each other in the circumferential direction are provided so as to have an axis of line symmetry with respect to the virtual straight line LS.

[0017] Therefore, in the following, of the pair of first target regions 31, one first target region 31 will be described, and a description of the other first target region 31 will be omitted. As shown in FIG. 2, the first target area 31 has a flat first general portion 32 and a first notch 33 that is formed in the outer circumferential surface 11a of the rotor side core piece 13 and has a generally trapezoidal shape in a plan view.

[0018] The first notch 33 penetrates the rotor side core piece 13 in the thickness direction. The pair of first cutouts 33 are provided so as to have an axis of line symmetry with respect to the imaginary straight line LS. The second target regions 41 are provided in a target region 30 different from the first target region 31 among the multiple target regions 30. In this embodiment, the second target regions 41 are adjacent to each other in the circumferential direction and are provided corresponding to the remaining eight magnet accommodating holes 14 different from the first target region 31. A pair of second target regions 41 adjacent to each other in the circumferential direction are provided so as to have an axis of line symmetry with respect to the virtual straight line LS.

[0019] Therefore, in the following, of the pair of second target regions 41, one second target region 41 will be described, and a description of the other second target region 41 will be omitted. The second target area 41 has a flat plate-shaped second general portion 42 and a second cutout 43 that is formed on the outer circumferential surface 11a of the rotor side core piece 13 and has a generally trapezoidal shape in a plan view.

[0020] The second notch 43 penetrates the rotor side core piece 13 in the thickness direction. The pair of second cutouts 43 are provided so as to have an axis of line symmetry with respect to the imaginary straight line LS. The arrangement of the first notches 33 in the first target region 31 is different from the arrangement of the second notches 43 in the second target region 41. In this embodiment, the pair of second notches 43 are provided at positions farther away from the virtual straight line LS than the pair of first notches 33 in the circumferential direction.

[0021] By rotating and stacking the rotor side core pieces 13, the first target areas 31 and the second target areas 41 overlap alternately in the axial direction. At this time, the first general portion 32 of one rotor side core piece 13 adjacent in the axial direction overlaps in the axial direction with the second notch 43 of the other rotor side core piece 13. In addition, the first notch 33 of one rotor side core piece 13 adjacent in the axial direction overlaps in the axial direction with the second general portion 42 of the other rotor side core piece 13.

[0022] <Stator 20> As shown in FIG. 1, the stator 20 includes a stator core 21 and a coil 27. The stator core 21 has a generally cylindrical shape and has a central hole 22. The stator core 21 and the rotor core 11 are positioned on the same axis C.

[0023] In the following description, the axial direction, radial direction, and circumferential direction of stator core 21 coincide with the axial direction, radial direction, and circumferential direction of rotor core 11. The stator core 21 is formed of a laminate in which a plurality of stator-side core pieces 23 are rotated and stacked. The stator-side core pieces 23 are made of electromagnetic steel sheets.

[0024] The stator core 21 has an annular yoke 24 and a plurality of teeth 25 extending radially inward from the yoke 24 and formed at intervals from one another in the circumferential direction.

[0025] A slot 26 that opens radially inward and extends radially is formed between circumferentially adjacent teeth 25. The slot 26 penetrates the stator core 21 in the axial direction and communicates with the center hole 22 in the radial direction.

[0026] A coil 27 wound around the outer periphery of the tooth 25 is inserted into the slot 26 . Inside the stator 20, the rotor core 11 is rotatably provided. In this embodiment, the first notch 33 corresponds to the irregular portion according to the present invention, and the first target area 31 corresponds to the target area having the irregular portion according to the present invention. Also, in this embodiment, the second target area 41 corresponds to the target area not having the irregular portion according to the present invention.

[0027] Next, the operation of this embodiment will be described. As shown in FIG. 3, the torque fluctuation caused by the magnetic interaction between the stator 20 and the rotor 10 in the multiple target regions 30 differs depending on whether the first notch 33 and the second notch 43 are present or not.

[0028] In Fig. 3, the change over time in torque fluctuation of the rotor 10 of this embodiment is shown by a solid line. The torque fluctuation of the rotor of Comparative Example 1 is shown by a dashed line, and the torque fluctuation of the rotor of Comparative Example 2 is shown by a dashed double-dashed line. Note that the rotor of Comparative Example 1 differs from the rotor 10 of this embodiment in that all of the target areas 30 of the rotor-side core piece 13 are constituted by the first target area 31 having the first notch 33. Also, the rotor of Comparative Example 2 differs from the rotor 10 of this embodiment in that all of the target areas 30 of the rotor-side core piece 13 are constituted by the second target area 41 having the second notch 43.

[0029] Therefore, the first target region 31 and the second target region 41 generate torque fluctuations different from each other. According to the above configuration, the first target area 31 and the second target area 41 of the rotor side core pieces 13 overlap in the axial direction of the rotor 10. Therefore, by rotating and stacking a plurality of rotor side core pieces 13 having the same shape, rotor side core pieces 13 having different torque fluctuation characteristics are stacked. This makes it possible for the stacked rotor side core pieces 13 to cancel out the torque fluctuations of the rotor side core pieces 13.

[0030] Next, the effects of this embodiment will be described. (1) The first target regions 31 are provided with first notches 33 arranged differently from the second target regions 41. The first target regions 31 and the second target regions 41 overlap in the axial direction.

[0031] According to such a configuration, the above-mentioned effects are achieved, and therefore the rotor 10 can be manufactured more easily than in the case where a plurality of types of rotor-side core pieces having mutually different arrangements are laminated. (2) The first notch 33 and the second notch 43 penetrate the rotor side core piece 13 in the thickness direction. The first target area 31 has a flat first general portion 32 at a portion overlapping with the second notch 43 in the axial direction. The second target area 41 has a flat second general portion 42 at a portion overlapping with the first notch 33 in the axial direction.

[0032] For example, in a configuration in which the irregularly shaped portion protrudes beyond the flat general portion of the rotor side core piece, the irregularly shaped portion will interfere with other rotor side core pieces adjacent to the rotor side core piece having the irregularly shaped portion.

[0033] In this regard, according to the above configuration, when multiple rotor side core pieces 13 are stacked, the flat second general portion 42 and the first notch 33 penetrating the rotor side core piece 13 in the thickness direction are overlapped. For this reason, the first notch 33 does not interfere with other rotor side core pieces 13 adjacent to the rotor side core piece 13 having the first notch 33.

[0034] Furthermore, when multiple rotor side core pieces 13 are stacked, the flat first general portions 32 and the second notches 43 penetrating the rotor side core pieces 13 in the thickness direction are overlapped. For this reason, the second notches 43 do not interfere with other rotor side core pieces 13 adjacent to the rotor side core piece 13 having the second notch 43.

[0035] (3) The first notch 33 and the second notch 43 are notches formed in the outer circumferential surface 11 a of the rotor side core piece 13 . According to this configuration, the gap between the notch formed in the outer peripheral surface 11a of the rotor-side core piece 13 and the stator 20 facing the notch, that is, the so-called air gap, is larger than other parts. Therefore, the magnetic flux distribution around the notch is more likely to change due to the gap than other parts. As a result, the torque fluctuations in the first target area 31 and the second target area 41 are significantly different. Therefore, it is possible to cancel out the torque fluctuations of the rotor-side core piece 13 with a simple configuration.

[0036] (4) A pair of magnet accommodating holes 14 adjacent to each other in the circumferential direction are provided so as to have an axis of line symmetry with respect to the imaginary line LS. A pair of first notches 33 and a pair of second notches 43 are provided so as to have an axis of line symmetry with respect to the imaginary line LS.

[0037] With this configuration, the occurrence of a difference in torque fluctuation characteristics caused by the first notch 33 and the second notch 43 between forward rotation and reverse rotation of the rotor 10 is suppressed. <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0038] In the present embodiment, the first notches 33 are provided in the eight first target regions 31 adjacent to each other in the circumferential direction, and the second notches 43 are provided in the eight second target regions 41 adjacent to each other in the circumferential direction, but the present invention is not limited to this. For example, as shown in FIG. 4, the first notches 133 may be provided in the four first target regions 131 adjacent to each other in the circumferential direction, and the second notches 143 may be provided in the four second target regions 141 adjacent to each other in the circumferential direction. The four first target regions 131 and the four second target regions 141 are alternately arranged in the circumferential direction. Even in this case, the four first target regions 131 and the four second target regions 141 may be overlapped in the axial direction by rotating and stacking the rotor-side core pieces 113. 5, a pair of first target areas 231 adjacent to each other in the circumferential direction may be provided with first notches 233, and a pair of second target areas 241 adjacent to each other in the circumferential direction may be provided with second notches 243. The pair of first target areas 231 and the pair of second target areas 241 are alternately arranged in the circumferential direction. Even in this case, the pair of first target areas 231 and the pair of second target areas 241 may be overlapped in the axial direction by rotating and stacking each rotor side core piece 213.

[0039] 6, the second notch may be omitted in the second target region 341. Even in this case, the shape or arrangement of the notch 333 in the first target region 331 can be appropriately changed so as to cancel out the torque fluctuation characteristic of the second target region 341.

[0040] In the present embodiment, a pair of magnet accommodating holes 14 adjacent to each other in the circumferential direction are arranged so as to have an axis of line symmetry about the virtual line LS, but this is not limited thereto. For example, a virtual line serving as an axis of line symmetry may be provided so that two sets of magnet accommodating holes 14 adjacent to each other in the circumferential direction are line symmetrical. Even in this case, it is sufficient that the first notches 33 in the two sets of magnet accommodating holes 14 are arranged so as to have an axis of line symmetry about the virtual line.

[0041] In the present embodiment, the irregular-shaped portion is configured by the first notch 33, but is not limited thereto. For example, as shown in FIG. 7, the irregular-shaped portion may be a through hole 433 formed in the first target area 431 of the rotor-side core piece 413. Also, as shown in FIG. 8, the irregular-shaped portion may be a through hole 533 communicating with the magnet accommodating hole 514 in the first target area 531 of the rotor-side core piece 513. In addition, in FIG. 7 and FIG. 8, the second target areas 441, 541 are configured only by the plate-shaped second general parts 442, 542. However, when the notches 33, 43 are formed in the rotor-side core piece 13, the gap between the outer peripheral surface 11a of the rotor 10 and the stator 20 is increased by the amount of each notch. Therefore, the magnetic flux acting between the stator 20 and the rotor 10 is reduced, which may reduce the torque acting on the rotor 10. In this regard, according to the above configuration, the irregular-shaped portion is the through-hole 433, 533 formed in the rotor-side core piece 413, 513, so the irregular-shaped portion does not increase the gap between the outer circumferential surface of the rotor 410, 510 and the stator 420, 520. This makes it possible to cancel out torque fluctuations while suppressing a decrease in motor torque caused by the provision of the irregular-shaped portion.

[0042] In the present embodiment, the second general portion 42 is provided in a portion of the target area 30 that overlaps with the first notch 33 in the axial direction, and the first general portion 32 is provided in a portion of the target area 30 that overlaps with the second notch 43 in the axial direction, but this is not limiting. For example, a protruding portion may be provided in a portion of the target area 30 that overlaps with the first notch 33 in the axial direction. Also, a protruding portion may be provided in a portion of the target area 30 that overlaps with the second notch 43 in the axial direction.

[0043] In this embodiment, eight first target regions 31 are provided, but it is sufficient that at least one first target region 31 is provided. In the present embodiment, the first notch 33 and the second notch 43 are arranged differently to generate torque fluctuation characteristics different from each other in the first target region 31 and the second target region 41, but the present invention is not limited to this. For example, the first notch 33 and the second notch 43 may have different shapes to generate torque fluctuation characteristics different from each other in the first target region 31 and the second target region 41.

[0044] In this embodiment, the rotor core 11 is formed by rotating and stacking the rotor side core pieces 13, but the rotor core 11 may also be formed by rotating and stacking a plurality of blocks formed by stacking a plurality of rotor side core pieces 13. In this case, it is sufficient that an irregular portion is formed in at least one of a plurality of target areas of the block.

[0045] In this embodiment, the rotor 10 is provided with the irregularly shaped portion, but the stator may be provided with the irregularly shaped portion. For example, as shown in FIG. 9, a tip surface 628 of the teeth 625 is provided with one first notch 633. Also, a tip surface 629 of the other teeth 626 is provided with two second notches 643. The teeth 625 and the other teeth 626 overlap in the axial direction. In this case, the torque fluctuation caused by the magnetic interaction between the stator 620 and the rotor 610 in the teeth 625 differs depending on the presence or absence of the first notch 633. Therefore, the teeth 625 having the first notch 633 and the other teeth 626 not having the first notch 633 generate torque fluctuations different from each other. According to the above configuration, the teeth 625 and the other teeth 626 overlap in the axial direction. Therefore, by rotating and stacking a plurality of stator side core pieces 623 having the same shape, stator side core pieces 623 having different torque fluctuation characteristics are stacked. This makes it possible for the stacked stator side core pieces 623 to cancel out the torque fluctuations of the stator side core pieces 623. Therefore, the stator 620 can be manufactured more easily than when multiple types of core pieces having different shapes are stacked. [Explanation of symbols]

[0046] 10,410,510,610…Rotor 11...Rotor core 11a...Outer surface 12...Center hole 13,413,513...Rotor side core piece 14,514…Magnet housing hole 15…Magnet 16…Resin 20,420,520,620…Stator 21…Stator core 22...Center hole 23,623…Stator core piece 24…York 25,625,626… Teeth 26…Slot 27…Coil 30…Target area 31,431,531…First target area 32…1st general section 33,433,633…First notch 41,441,541…Second target area 42,442,542…2nd general section 43,643…Second notch 333…Notch 533...Through hole 628,629…Tip surface

Claims

1. A rotor that is an inner rotor type and is applied to an embedded magnet motor, and has a rotor core formed by rotating and stacking a plurality of iron core pieces or a plurality of blocks formed by stacking a plurality of the iron core pieces, the rotor core has a plurality of magnet accommodating holes spaced apart in a circumferential direction of the rotor, A magnet is accommodated in the magnet accommodating hole, When a portion of the rotor core between the magnet accommodating hole and an outer peripheral surface of the rotor core located on the outer peripheral side of the magnet accommodating hole is set as a target area, At least one of the plurality of target regions is provided with an irregular portion having a different shape or arrangement from the other target regions; the target area of ​​the core piece or the block having the irregular portion and the target area of ​​the core piece or the block not having the irregular portion overlap in the axial direction of the rotor; Rotor.

2. the deformed portion penetrates the core piece or the block in a thickness direction, The target area of ​​the core piece or the block not having the deformed portion has a flat general portion that overlaps with the deformed portion in the axial direction. The rotor of claim 1 .

3. The deformed portion is a notch formed on the outer peripheral surface of the core piece or the block. A rotor according to claim 2.

4. The irregularly shaped portion is a through hole formed in the core piece or the block. A rotor according to claim 2.

5. a pair of the magnet accommodating holes adjacent to each other in a circumferential direction of the rotor are provided to have an axis of line symmetry with respect to a virtual line extending in a radial direction of the rotor, The pair of irregular shaped portions are provided so as to have an axis of line symmetry with respect to the virtual straight line. A rotor according to any one of claims 1 to 4.

6. A stator that is applied to an inner rotor type and embedded magnet type motor and has a stator core formed by rotating and stacking a plurality of iron core pieces or a plurality of blocks formed by stacking a plurality of the iron core pieces, The stator core has an annular yoke and a plurality of teeth protruding from the yoke in a radial direction of the yoke, A coil is wound around the teeth, At least one of the teeth is provided with a deformed portion having a shape or arrangement different from that of the other teeth, The teeth of the core pieces or the blocks having the irregularly shaped portions and the teeth of the core pieces or the blocks not having the irregularly shaped portions are overlapped in the axial direction of the stator. Stator.

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