Rotor and motor

Abstract

To provide a rotor and a motor that can improve the torque of a motor.SOLUTION: The rotor has a plurality of magnets and a rotor core. The magnets are arranged in a circumferential direction around a center axis extending vertically. The rotor core is a laminate body formed by laminating a steel plate in an axial direction. At least one layer of the rotor core has a first steel plate and a plurality of second steel plates. The first steel plate has a first core center part SP111a and a first core magnetic part SP121a. The first core magnetic part SP121a is arranged radially outward of the first core center part SP111a. The second steel plate has a second core magnetic part SP121b. The second core magnetic part SP121b is arranged in a circumferential direction radially outward of the first core center part SP111a. The second steel plate is arranged to be separate from the first core center part SP111a.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Conventionally, rotors having a rotor core and a plurality of magnets arranged circumferentially around a central axis are known (see, for example, Patent Document 1). Patent Document 1 describes a rotor including a cylindrical rotor core fitted and fixed to the outside of a rotating shaft, and a plurality of resin magnets arranged in a line along the circumferential direction on the rotor core. A plurality of magnet storage holes are formed in the rotor core. Slits are formed at the radial outer ends of the magnet storage holes. The magnets are arranged inside the magnet storage holes and exposed on the outer peripheral surface of the rotor core. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-144386 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the rotor of Patent Document 1, the magnet is filled in the magnet storage hole. That is, the radially inner end face of the magnet contacts the rotor core located between the magnet and the rotating shaft. Therefore, the magnetic flux of the magnet easily flows through the rotor core between the magnet and the rotating shaft. The magnetic flux flowing through the rotor core between the magnet and the rotating shaft does not contribute to the rotational torque of the rotor. Therefore, it is difficult to improve the torque of the motor with the rotor of Patent Document 1.

[0005] The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a rotor and a motor that are capable of improving the torque of the motor. [Means for solving the problem]

[0006] An exemplary rotor of the present invention includes a plurality of magnets and a rotor core. The plurality of magnets are arranged in a circumferential direction around a central axis extending vertically. The rotor core is a laminate in which steel plates are stacked in the axial direction. At least one layer of the rotor core includes a first steel plate and a plurality of second steel plates. The first steel plates are In the one layer, The rotor includes a first core central portion and a first core magnetic pole portion. The first core magnetic pole portion is disposed radially outward of the first core central portion. , connected to the first core central portion The second steel plate has a second core magnetic pole portion. The second core magnetic pole portion is In the one layer The second steel plate is disposed in the circumferential direction on the radially outer side of the first core central portion. Without being connected by steel plates The rotor core has a resin portion that covers at least a portion of the rotor core and the periphery of the plurality of magnets in a cross section passing through the central axis.

[0007] An exemplary motor of the present invention includes the rotor described above and a stator. The stator is disposed radially outward of the rotor. Effect of the Invention

[0008] According to an exemplary embodiment of the present invention, a rotor and a motor capable of improving the torque of the motor can be provided. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing the structure of a motor having a rotor according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view showing the structure of the rotor of the embodiment of the present invention with the resin portion removed. [Diagram 3] FIG. 3 is an exploded perspective view of a portion of the rotor core according to one embodiment of the present invention. [Figure 4] FIG. 4 is a plan view showing the structure of a first plate member according to an embodiment of the present invention. [Diagram 5]FIG. 5 is a plan view showing the structure of a second plate member according to an embodiment of the present invention. [Figure 6] FIG. 6 is a plan view showing the structure of a third plate member according to an embodiment of the present invention. [Figure 7] FIG. 7 is a plan view showing the structure of a third plate member according to an embodiment of the present invention. [Figure 8] FIG. 8 is a perspective view showing the structure of a rotor according to one embodiment of the present invention. [Figure 9] FIG. 9 is a cross-sectional view showing a state in which the rotor core and magnets according to one embodiment of the present invention are covered with a resin portion using a lower mold and an upper mold. [Figure 10] FIG. 10 is a cross-sectional view for explaining a manufacturing method of a rotor according to an embodiment of the present invention, showing a state in which the rotor core is placed in a jig. [Figure 11] FIG. 11 is a partial enlarged view of the first plate member, the second plate member, and the third plate member of the rotor according to one embodiment of the present invention. [Figure 12] FIG. 12 is a plan view showing the structure of a second plate member of a first modified example of an embodiment of the present invention. [Figure 13] FIG. 13 is a plan view showing the structure of a first plate member and a second plate member according to a second modified example of the embodiment of the present invention. [Figure 14] FIG. 14 is a plan view showing the structure of a first plate member and a second plate member according to a third modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and description thereof will not be repeated.

[0011] In this specification, for convenience, the direction of the central axis AX of the motor (see FIG. 1) may be described as the up-down direction. In this specification, the up-down direction is defined for convenience of explanation and does not need to coincide with the vertical direction. In addition, the up-down direction is defined merely for convenience of explanation and does not limit the orientation of the rotor and motor according to the present invention when used and assembled. Furthermore, the direction parallel to the central axis AX of the motor is simply described as the "axial direction AD", and the radial direction and circumferential direction centered on the central axis AX of the motor are simply described as the "radial direction RD" and the "circumferential direction CD". In addition, "plan view" refers to viewing an object from the axial direction AD. In this specification, "parallel direction" also includes a direction that is approximately parallel. In addition, "upper in the axial direction AD" can be described as "one side of the axial direction AD", and "lower in the axial direction AD" can be described as "other side of the axial direction AD".

[0012] A motor 1 having a rotor 10 according to an embodiment of the present invention will be described with reference to Fig. 1 to Fig. 11. First, the motor 1 will be described with reference to Fig. 1. Fig. 1 is a cross-sectional view showing the structure of a motor 1 having a rotor 10 according to an embodiment of the present invention. In Fig. 1 and Figs. 9 and 10 described later, for ease of understanding, a cross section passing through the central axis AX and the core magnetic pole portion 121 is shown on the left side, and a cross section passing through the central axis AX and the magnet 11 is shown on the right side.

[0013] As shown in FIG. 1, the motor 1 includes a rotor 10, a stator 20, a shaft 2, a casing 3, a first cover member 4, a first bearing 41, a second cover member 5, a second bearing 51, and a substrate 6.

[0014] The rotor 10 rotates about a central axis AX extending vertically. The rotor 10 is housed in an internal space S. The internal space S is a space surrounded by a casing 3, a first cover member 4, and a second cover member 5. The detailed structure of the rotor 10 will be described later.

[0015] The stator 20 is disposed in an annular shape about the central axis AX. The stator 20 is housed in a casing 3. The stator 20 is molded from resin integrally with the casing 3. The stator 20 is disposed outward in the radial direction RD of the rotor 10. That is, the motor 1 of this embodiment is an inner rotor type motor.

[0016] The stator 20 includes a stator core 21, an insulator 22, and a plurality of coils 23. The stator core 21 is, for example, a laminate in which steel plate materials are laminated in the axial direction AD. The steel plate material constituting the stator core 21 is, for example, an electromagnetic steel plate. The insulator 22 faces the rotor 10 in the radial direction RD. The insulator 22 is, for example, an insulating member such as a resin. The insulator 22 covers the stator core 21 except for at least the surface of the stator core 21 that faces the rotor 10. The coil 23 is wound around the stator core 21 via the insulator 22. When a driving current is supplied to the coil 23, a magnetic flux is generated around the coil 23. Then, a torque in the circumferential direction CD is generated by the action of magnetic repulsion and attraction between the stator 20 and the rotor 10. Therefore, the rotor 10 rotates around the central axis AX.

[0017] The shaft 2 extends along a central axis AX. The shaft 2 is a substantially cylindrical member. The shaft 2 is fixed to the rotor 10 and rotates about the central axis AX in response to the rotation of the rotor 10.

[0018] The casing 3 houses the rotor 10 and the stator 20. Specifically, the casing 3 is substantially cylindrical and centered on a central axis AX that extends vertically. The casing 3 is open at its axially upper side. The first cover member 4 covers the opening of the casing 3. The casing 3 contains resin as a material.

[0019] The first cover member 4 is disposed in an upper portion of the motor 1 in the axial direction AD. The second cover member 5 is disposed in a lower portion of the motor 1 in the axial direction AD. The first cover member 4 has a cylindrical first bearing retaining portion 42 and a through hole formed in the center of the first bearing retaining portion 42. The shaft 2 passes through the through hole. The first bearing retaining portion 42 retains the first bearing 41. The second cover member 5 has a cylindrical second bearing retaining portion 52. The second bearing retaining portion 52 retains the second bearing 51. The first bearing 41 and the second bearing 51 rotatably support the shaft 2. In other words, the first bearing 41 and the second bearing 51 rotatably support the rotor 10. The first bearing 41 and the second bearing 51 are, for example, rolling bearings. The first cover member 4 and the second cover member 5 are fixed to the casing 3.

[0020] The substrate 6 is accommodated in the internal space S. The substrate 6 is disposed substantially perpendicular to the axial direction AD. For example, the substrate 6 is a printed circuit board on which wiring is printed, and has various electronic components.

[0021] Next, the structure of the rotor 10 will be described in detail with reference to Fig. 2. Fig. 2 is a perspective view showing the structure of the rotor 10 of this embodiment excluding the resin part 12. As shown in Fig. 2, the rotor 10 has a plurality of magnets 11 and a rotor core 100.

[0022] The magnet 11 is a permanent magnet. The magnet 11 has a substantially rectangular parallelepiped shape. The magnets 11 are arranged in a circumferential direction CD around a central axis AX. The magnets 11 are arranged at equal intervals in the circumferential direction CD. Both end faces of the magnet 11 in the circumferential direction CD are magnetic pole faces (N pole or S pole). The magnetic pole faces of adjacent magnets 11 facing each other in the circumferential direction CD have the same pole.

[0023] The rotor core 100 has a shaft connecting portion 110 and a plurality of magnetic pole portions 120. The shaft connecting portion 110 has a generally cylindrical shape centered on the central axis AX. The shaft connecting portion 110 has a through hole 110a that penetrates along the central axis AX. The shaft 2 is disposed inside the through hole 110a. The shaft connecting portion 110 is connected to the shaft 2. Therefore, when the rotor core 100 rotates, the shaft 2 rotates.

[0024] The magnetic pole portion 120 has a generally sector shape in a plan view. The multiple magnetic pole portions 120 are arranged radially outward of the shaft coupling portion 110 in the radial direction RD. The multiple magnetic pole portions 120 are arranged in the circumferential direction CD around the central axis AX. The multiple magnetic pole portions 120 are arranged at equal intervals in the circumferential direction CD. The magnets 11 are located between the magnetic pole portions 120 adjacent to each other in the circumferential direction CD. That is, the magnetic pole portions 120 and the magnets 11 are arranged alternately in the circumferential direction CD.

[0025] Next, the structure of the rotor core 100 will be described in further detail with reference to Figures 2 and 3. Figure 3 is an exploded perspective view of a portion of the rotor core 100 of this embodiment.

[0026] As shown in Figs. 2 and 3, the rotor core 100 is a laminate in which steel plate materials are laminated in the axial direction AD. That is, the rotor core 100 has a plurality of layers. The steel plate material constituting the rotor core 100 is, for example, an electromagnetic steel plate. The shaft connecting portion 110 has a plurality of layers. Each of the plurality of magnetic pole portions 120 has a plurality of layers. Specifically, each layer of the rotor core 100 has one circular core center portion 111 having a hole 111a at the center, and a plurality of core magnetic pole portions 121 having a substantially sector shape. The shaft connecting portion 110 is formed by laminating a plurality of core center portions 111. Each magnetic pole portion 120 is formed by laminating a plurality of core magnetic pole portions 121.

[0027] 3, at least one layer of the rotor core 100 has a first plate member 101 and a plurality of second plate members 102. The first plate member 101 has a core central portion 111 and a core magnetic pole portion 121 arranged outward in the radial direction RD of the core central portion 111. The second plate member 102 has a core magnetic pole portion 121 arranged in the circumferential direction CD outward in the radial direction RD of the core central portion 111. The core magnetic pole portion 121 of the second plate member 102 is arranged with a gap between it and the core central portion 111 of the first plate member 101.

[0028] The first plate member 101 in at least one layer (see layers L2 to L5 in FIG. 3) of the rotor core 100 has a plurality of core magnetic pole portions 121. The plurality of core magnetic pole portions 121 of the first plate member 101 are connected to the core central portion 111 at equal intervals in the circumferential direction CD. For example, in this embodiment, each first plate member 101 has two core magnetic pole portions 121. The two core magnetic pole portions 121 of each first plate member 101 are connected to the core central portion 111 at intervals of 180° in the circumferential direction CD.

[0029] In a layer (see layers L2 to L5 in FIG. 3) having a first plate member 101 and a plurality of second plate members 102, the core magnetic pole portions 121 of the first plate members 101 are arranged to be shifted in the circumferential direction CD relative to the core magnetic pole portions 121 of the first plate members 101 of other layers. The laminated structure of the first plate members 101 is not particularly limited, but in this embodiment, the first plate members 101 are laminated so that the core magnetic pole portions 121 of adjacent first plate members 101 are shifted by one pitch (e.g., 36°) in the circumferential direction CD. Note that, for example, a plurality of first plate members 101 may be laminated so that the core magnetic pole portions 121 are shifted by several pitches in the circumferential direction CD.

[0030] The rotor core 100 has a third plate member 103 in a layer (see layer L1 in FIG. 3) different from the layer having the first plate member 101 and the plurality of second plate members 102. The third plate member 103 has a core central portion 111 and a plurality of core magnetic pole portions 121 arranged on the radially outer side of the core central portion 111 in the radial direction RD. The third plate member 103 has all of the core magnetic pole portions 121 arranged on the radially outer side of the core central portion 111 in the radial direction RD. The number of the core magnetic pole portions 121 of the third plate member 103 is the same as the number of the magnetic pole portions 120 of the rotor core 100. In other words, the number of the core magnetic pole portions 121 of the third plate member 103 is the same as the number of the magnets 11. In other words, the number of the core magnetic pole portions 121 of the third plate member 103 is the same as the number of the poles of the rotor 10.

[0031] The third plate members 103 may be disposed in any layer of the rotor core 100, but in this embodiment, for example, they are disposed at both ends in the axial direction AD of the rotor core 100. That is, the third plate members 103 are disposed in the uppermost layer UL and the lowermost layer LL of the rotor core 100 (see FIG. 2).

[0032] Next, the structure of the first plate member 101 will be further described with reference to Fig. 4. Fig. 4 is a plan view showing the structure of the first plate member 101 of this embodiment. As shown in Fig. 4, the first plate member 101 further has a core coupling portion 131. The core coupling portion 131 extends along the radial direction RD. The core coupling portion 131 couples the core magnetic pole portion 121 and the core central portion 111 in the radial direction RD.

[0033] The first plate member 101 further has an inner circumferential protruding portion 141. In this embodiment, the first plate member 101 has two inner circumferential protruding portions 141 for one core connecting portion 131. The inner circumferential protruding portions 141 protrude from the core connecting portion 131 in the circumferential direction CD. Therefore, the inner circumferential protruding portions 141 can restrict the magnet 11 from moving inward in the radial direction RD. The inner circumferential protruding portions 141 are an example of the "circumferential protruding portion" in the present invention.

[0034] The first plate member 101 further has an outer circumferential protruding portion 151. In this embodiment, the first plate member 101 has two outer circumferential protruding portions 151 for one core magnetic pole portion 121. The outer circumferential protruding portions 151 protrude in the circumferential direction CD from the outer end portion in the radial direction RD of the core magnetic pole portion 121. Therefore, the outer circumferential protruding portions 151 can restrict the movement of the magnet 11 outward in the radial direction RD.

[0035] Next, the structure of the second plate member 102 will be further described with reference to Fig. 5. Fig. 5 is a plan view showing the structure of the second plate member 102 of this embodiment. As shown in Fig. 5, the second plate member 102 further has an outer circumferential protruding portion 151, similar to the first plate member 101. In this embodiment, the second plate member 102 has two outer circumferential protruding portions 151. The structure of the outer circumferential protruding portions 151 of the second plate member 102 is similar to the structure of the outer circumferential protruding portions 151 of the first plate member 101.

[0036] Next, the structure of the third plate member 103 will be further described with reference to Fig. 6. Fig. 6 is a plan view showing the structure of the third plate member 103 of this embodiment. As shown in Fig. 6, the third plate member 103 further has a core coupling portion 131, similar to the first plate member 101. The structure of the core coupling portion 131 of the third plate member 103 is similar to the structure of the core coupling portion 131 of the first plate member 101.

[0037] Similarly to the first plate member 101, the third plate member 103 further has inner circumferential protruding portions 141. In this embodiment, the third plate member 103 has two inner circumferential protruding portions 141 for one core coupling portion 131. The structure of the inner circumferential protruding portions 141 of the third plate member 103 is similar to the structure of the inner circumferential protruding portions 141 of the first plate member 101.

[0038] Similarly to the first plate member 101 and the second plate member 102, the third plate member 103 further has outer circumferential protruding portions 151. In this embodiment, the third plate member 103 has two outer circumferential protruding portions 151 for one core magnetic pole portion 121. The structure of the outer circumferential protruding portions 151 of the third plate member 103 is similar to the structure of the outer circumferential protruding portions 151 of the first plate member 101 and the second plate member 102.

[0039] Next, the structure of the core magnetic pole portion 121 will be further described with reference to Figs. 2, 3, 6, and 7. Fig. 7 is a plan view showing the structure of the third plate member 103a of this embodiment. As shown in Figs. 2 and 3, each layer of the rotor core 100 has a plurality of core magnetic pole portions 121. In this embodiment, each core magnetic pole portion 121 has at least one hole 121a penetrating in the axial direction AD. The hole 121a of a core magnetic pole portion 121 is continuous with the hole 121a of another core magnetic pole portion 121 adjacent in the axial direction AD.

[0040] The number of holes 121a in each core magnetic pole portion 121 is not particularly limited, but in this embodiment, each core magnetic pole portion 121 has one or two holes 121a. In this embodiment, for example, each core magnetic pole portion 121 of the third plate member 103a (see FIG. 7) arranged in the lowest layer LL of the rotor core 100 has one hole 121a. Each core magnetic pole portion 121 in a layer other than the lowest layer LL of the rotor core 100 has two holes 121a. The structure of the third plate member 103a is similar to the structure of the third plate member 103, except for the number of holes 121a.

[0041] That is, in this embodiment, the number of holes 121a in the core magnetic pole portion 121 at one end in the axial direction AD of the rotor core 100 is different from the number of holes 121a in the core magnetic pole portion 121 at the other end in the axial direction AD of the rotor core 100. Therefore, the top and bottom of the rotor core 100 can be easily distinguished from each other. Note that the number of holes 121a in the core magnetic pole portion 121 at one end in the axial direction AD of the rotor core 100 may be the same as the number of holes 121a in the core magnetic pole portion 121 at the other end in the axial direction AD of the rotor core 100. That is, for example, the bottom layer LL of the rotor core 100 may be the third plate member 103.

[0042] In this embodiment, all of the core central portions 111 of the rotor core 100 have the same shape. However, all of the core central portions 111 do not have to have the same shape. That is, the core central portions 111 may have slightly different shapes. For example, the core central portions 111 in different layers may have different shapes. Also, in this embodiment, all of the core magnetic pole portions 121 of the rotor core 100 have the same shape. However, all of the core magnetic pole portions 121 do not have to have the same shape. That is, the core magnetic pole portions 121 may have slightly different shapes. For example, the core magnetic pole portions 121 in different layers may have different shapes. Also, the core magnetic pole portions 121 in the same layer may have different shapes.

[0043] Next, the rotor core 100 of this embodiment will be further described. As shown in Fig. 3, the first plate member 101 of the layer L5 of the rotor core 100 is the first steel plate SP1, and the second plate member 102 of the layer L5 is the second steel plate SP2. The first plate member 101 of the layer L4 is the third steel plate SP3, and the second plate member 102 of the layer L4 is the fourth steel plate SP4. The third plate member 103 of the layer L1 is the fifth steel plate SP5. The third plate member 103a is also the fifth steel plate SP5. The rotor core 100 will be described using the first steel plate SP1 to the fifth steel plate SP5.

[0044] At least one layer (see layer L5 in FIG. 3) of rotor core 100 has a first steel plate SP1 and a plurality of second steel plates SP2. Rotor core 100 has a plurality of steel plates including the first steel plate SP1 and the second steel plates SP2.

[0045] The first steel plate SP1 has a first core central portion SP111a and a first core magnetic pole portion SP121a. Therefore, the positional accuracy of the first core magnetic pole portion SP121a in the radial direction RD can be improved. In addition, the rigidity for withstanding the centrifugal force acting on the first core magnetic pole portion SP121a during rotation of the rotor 10 can be secured. The first core central portion SP111a is the core central portion 111 of the first plate member 101. The first core magnetic pole portion SP121a is the core magnetic pole portion 121 of the first plate member 101. That is, the multiple steel plates of the rotor core 100 have multiple core magnetic pole portions 121 including the first core magnetic pole portion SP121a. The first core magnetic pole portion SP121a is disposed outward in the radial direction RD of the first core central portion SP111a.

[0046] The second steel plate SP2 has a second core magnetic pole portion SP121b arranged in the circumferential direction CD outside the first core central portion SP111a in the radial direction RD. The second core magnetic pole portion SP121b is the core magnetic pole portion 121 of the second plate member 102. That is, the multiple steel plates of the rotor core 100 have multiple core magnetic pole portions 121 including the second core magnetic pole portion SP121b. The second core magnetic pole portion SP121b is arranged with a gap between it and the first core central portion SP111a. Therefore, the magnetic flux of the magnet 11 is less likely to leak inward in the radial direction RD. As a result, the torque of the motor 1 can be improved.

[0047] Moreover, rotor core 100 has a third steel plate SP3 and a plurality of fourth steel plates SP4 in a layer (see layer L4 in FIG. 3) different from layer L5.

[0048] The third steel plate SP3 has a second core central portion SP111b and a third core magnetic pole portion SP121c. Therefore, the positional accuracy of the third core magnetic pole portion SP121c in the radial direction RD can be improved. In addition, the rigidity required to withstand the centrifugal force acting on the third core magnetic pole portion SP121c during rotation of the rotor 10 can be ensured. The second core central portion SP111b is the core central portion 111 of the first plate member 101. The third core magnetic pole portion SP121c is the core magnetic pole portion 121 of the first plate member 101. The third core magnetic pole portion SP121c is disposed outward in the radial direction RD of the second core central portion SP111b.

[0049] The fourth steel plate SP4 has a fourth core magnetic pole portion SP121d arranged in the circumferential direction CD outward in the radial direction RD from the second core central portion SP111b. The fourth core magnetic pole portion SP121d is the core magnetic pole portion 121 of the second plate member 102. The fourth core magnetic pole portion SP121d is arranged with a gap between it and the second core central portion SP111b.

[0050] The first core magnetic pole portion SP121a is arranged offset in the circumferential direction CD with respect to the third core magnetic pole portion SP121c. Therefore, the portion connecting the core magnetic pole portion 121 and the core central portion 111 is offset in the circumferential direction CD. That is, the core coupling portion 131 where magnetic flux leakage occurs is offset in the circumferential direction CD. This can prevent the portions where magnetic flux leakage occurs from overlapping in the axial direction AD. As a result, it is possible to prevent magnetic flux from flowing in the portion connecting the core magnetic pole portion 121 and the core central portion 111. In particular, the smaller the area of ​​the portion connecting the core magnetic pole portion 121 and the core central portion 111, the more likely magnetic saturation occurs, and therefore magnetic flux leakage can be further suppressed.

[0051] The first steel plate SP1 has a plurality of first core magnetic pole portions SP121a. In this embodiment, the first steel plate SP1 has two first core magnetic pole portions SP121a. The first core magnetic pole portions SP121a are connected to the first core central portion SP111a at equal intervals in the circumferential direction CD. This can further prevent deviations in the magnetic characteristics, positional accuracy, and rigidity of the rotor core 100.

[0052] Moreover, the third steel plate SP3 has a plurality of third core magnetic pole portions SP121c. In this embodiment, the third steel plate SP3 has two third core magnetic pole portions SP121c. The third core magnetic pole portions SP121c are connected to the second core central portion SP111b at equal intervals in the circumferential direction CD. This can further prevent deviations in the magnetic characteristics, positional accuracy, and rigidity of the rotor core 100.

[0053] The rotor core 100 has a fifth steel plate SP5 in a layer different from the layer L5 (see the layer L1 in FIG. 3).

[0054] The fifth steel plate SP5 has a third core central portion SP111c and a fifth core magnetic pole portion SP121e. The third core central portion SP111c is the core central portion 111 of the third plate member 103. The fifth core magnetic pole portion SP121e is the core magnetic pole portion 121 of the third plate member 103. The fifth core magnetic pole portion SP121e is disposed radially outward of the third core central portion SP111c. The fifth steel plate SP5 has all the fifth core magnetic pole portions SP121e disposed radially outward of the third core central portion SP111c. The number of the fifth core magnetic pole portions SP121e of the fifth steel plate SP5 is the same as the number of the magnetic pole portions 120 of the rotor core 100. In other words, the number of the fifth core magnetic pole portions SP121e of the fifth steel plate SP5 is the same as the number of the magnets 11. In other words, the number of the fifth core magnetic pole portions SP121e of the fifth steel plate SP5 is the same as the number of poles of the rotor 10. Moreover, all of the fifth core magnetic pole portions SP121e are connected to the third core central portion SP111c. That is, the fifth steel plate SP5 in which all of the core magnetic pole portions 121 are connected to the core central portion 111 is used as one layer of the rotor core 100. This can further enhance the rigidity of the rotor 10.

[0055] The fifth steel plate SP5 may be disposed in any layer of the rotor core 100, but in this embodiment, for example, it is disposed at both ends in the axial direction AD of the rotor core 100. That is, the fifth steel plate SP5 is disposed in the uppermost layer UL and the lowermost layer LL (see FIG. 2) of the rotor core 100. Therefore, the fifth steel plate SP5 can sandwich all layers other than the uppermost layer UL and the lowermost layer LL in the axial direction AD. As a result, for example, even if the rotor core 100 is lifted during the manufacture of the rotor 10, for example, the second steel plate SP2 can be prevented from falling from the rotor core 100.

[0056] The first steel plate SP1 further has a core connecting portion 131. The core connecting portion 131 of the first steel plate SP1 connects the first core pole portion SP121a and the first core center portion SP111a. Therefore, it is possible to suppress leakage of the magnetic flux of the magnet 11 to the inside in the radial direction RD, compared to a case in which the diameter of the first core center portion SP111a is increased and the first core pole portion SP121a is directly connected to the first core center portion SP111a, for example.

[0057] The third steel plate SP3 further has a core connecting portion 131. The core connecting portion 131 of the third steel plate SP3 connects the third core pole portion SP121c and the second core center portion SP111b. Therefore, it is possible to suppress leakage of the magnetic flux of the magnet 11 to the inside in the radial direction RD, compared to a case in which, for example, the diameter of the second core center portion SP111b is increased and the second core center portion SP111b and the third core pole portion SP121c are directly connected.

[0058] The fifth steel plate SP5 further has a core connecting portion 131. The core connecting portion 131 of the fifth steel plate SP5 connects the fifth core pole portion SP121e and the third core center portion SP111c. Therefore, it is possible to suppress leakage of the magnetic flux of the magnet 11 to the inside in the radial direction RD, compared to a case in which, for example, the diameter of the third core center portion SP111c is increased and the third core center portion SP111c and the fifth core pole portion SP121e are directly connected.

[0059] The first steel plate SP1 further has an inner circumferential protruding portion 141. In this embodiment, the first steel plate SP1 has two inner circumferential protruding portions 141 for one first core pole portion SP121a. The inner circumferential protruding portions 141 of the first steel plate SP1 protrude in the circumferential direction CD from the core connecting portion 131. Therefore, the inner circumferential protruding portions 141 of the first steel plate SP1 can restrict the magnet 11 from moving inward in the radial direction RD.

[0060] The third steel plate SP3 further has an inner circumferential protruding portion 141. In this embodiment, the third steel plate SP3 has two inner circumferential protruding portions 141 for one third core pole portion SP121c. The inner circumferential protruding portion 141 of the third steel plate SP3 protrudes from the core coupling portion 131 in the circumferential direction CD.

[0061] The fifth steel plate SP5 further has an inner circumferential protruding portion 141. In this embodiment, the fifth steel plate SP5 has two inner circumferential protruding portions 141 for one fifth core pole portion SP121e. The inner circumferential protruding portion 141 of the fifth steel plate SP5 protrudes in the circumferential direction CD from the core connecting portion 131. The effect of the inner circumferential protruding portions 141 of the third steel plate SP3 and the fifth steel plate SP5 is similar to the effect of the inner circumferential protruding portion 141 of the first steel plate SP1.

[0062] Each layer (see layers L1 to L5 in FIG. 3) of the rotor core 100 has a plurality of core magnetic pole portions 121. The plurality of core magnetic pole portions 121 in at least one layer (see layer L5 in FIG. 3) include a first core magnetic pole portion SP121a and a second core magnetic pole portion SP121b. Each core magnetic pole portion 121 has at least one hole 121a penetrating in the axial direction AD. The hole 121a of the core magnetic pole portion 121 is continuous with the hole 121a of another core magnetic pole portion 121 adjacent in the axial direction AD. A part of the resin portion 12, which will be described later, is disposed inside the hole 121a. Therefore, since the resin is disposed in the hole 121a of the core magnetic pole portion 121, the layers of the rotor core 100 can be fixed more firmly.

[0063] Next, the structure of the rotor 10 according to one embodiment of the present invention will be further described with reference to Fig. 8 and Fig. 9. Fig. 8 is a perspective view showing the structure of the rotor 10 of this embodiment. Fig. 9 is a cross-sectional view showing the rotor core 100 and magnet 11 of this embodiment covered with the resin part 12 using a lower mold 310 and an upper mold 320.

[0064] 8, the rotor 10 further has a resin portion 12. The resin portion 12 covers at least a portion of the rotor core 100 and at least a portion of the multiple magnets 11. This allows the layers of the rotor core 100 and the magnets 11 to be fixed in place. For example, the resin portion 12 covers the rotor core 100 and the multiple magnets 11 except for the periphery of the through holes 110a of the rotor core 100 and the outer circumferential surface of the rotor core 100.

[0065] 8 and 9, the resin part 12 has a plurality of upper holes 12a and a plurality of upper holes 12b. The upper holes 12a are disposed axially above the magnet 11. Therefore, the magnet 11 is exposed axially above through the upper holes 12a. The upper holes 12b are disposed axially above the magnetic pole parts 120 of the rotor core 100. Therefore, the magnetic pole parts 120 are exposed axially above through the upper holes 12b.

[0066] The resin part 12 has a plurality of lower holes 12c and a plurality of lower holes 12d. The lower holes 12c are disposed axially below the magnet 11. Therefore, the magnet 11 is exposed axially downward through the lower holes 12c. The lower holes 12d are disposed axially below the magnetic pole parts 120 of the rotor core 100. Therefore, the magnetic pole parts 120 are exposed axially downward through the lower holes 12d.

[0067] Next, a manufacturing method of the rotor 10 will be described with reference to Fig. 9 to Fig. 11. Fig. 10 is a cross-sectional view for explaining the manufacturing method of the rotor 10 according to this embodiment, and shows a state in which the rotor core 100 is placed in a jig 200. Fig. 11 is a partially enlarged view of the first plate member 101, the second plate member 102, the third plate member 103, and 103a of the rotor 10 according to this embodiment.

[0068] First, a first plate member 101, a second plate member 102, a third plate member 103, and a third plate member 103a are obtained by punching a steel plate using a punching die (not shown). The first plate member 101, the second plate member 102, the third plate member 103, and a third plate member 103a after the punching process are stacked in a predetermined position, in a predetermined order, and in a predetermined number of sheets to obtain the rotor core 100. The first plate member 101, the second plate member 102, and the third plate member 103, and a third plate member 103a are provided with crimping portions to fix the plate members to each other.

[0069] As shown in FIG. 10, the obtained rotor core 100 is placed in a jig 200. The jig 200 has a flat base 201 and a plurality of positioning pins 202. The positioning pins 202 protrude axially upward from the base 201. The positioning pins 202 are placed at positions corresponding to the holes 121a of the rotor core 100. One positioning pin 202 is placed for each magnetic pole portion 120. Specifically, the positioning pin 202 is placed at a position corresponding to the hole 121a on the outer side in the radial direction RD, out of the two holes 121a of the core magnetic pole portion 121. In other words, the positioning pin 202 is placed at a position corresponding to the hole 121a of the third plate member 103a (see FIG. 7). Then, the rotor core 100 is placed in the jig 200 with the third plate member 103a in the lowest layer LL (see FIG. 2). At this time, the third plate member 103 (see FIG. 6) is placed in the uppermost layer UL (see FIG. 2). Additionally, the positioning pin 202 is disposed within the hole 121a.

[0070] Here, since the first plate member 101, the second plate member 102, and the third plate member 103 and 103a are formed by punching, as shown in FIG. 11, the first plate member 101, the second plate member 102, and the third plate member 103 and 103a have sagging P1 and burrs P2. The first plate member 101, the second plate member 102, and the third plate member 103 and 103a are stacked in a state in which the direction of the sagging P1 and the direction of the burrs P2 are aligned. In this embodiment, for example, the sagging P1 is formed on the upper part of the first plate member 101, the second plate member 102, and the third plate member 103 and 103a, and the burrs P2 are formed on the lower part. When the magnet 11 is attached to the rotor core 100, the magnet 11 is inserted from the sagging P1 side toward the burr P2 side, thereby preventing the magnet 11 from getting caught on the rotor core 100. Therefore, in this embodiment, for example, as shown in FIG. 10, the magnet 11 is attached to the rotor core 100 from above in the axial direction.

[0071] That is, in this embodiment, the number of holes 121a (two) of the core magnetic pole portion 121 at one axial AD end of the rotor core 100 is different from the number of holes 121a (one) of the core magnetic pole portion 121 at the other axial AD end of the rotor core 100. Therefore, the top and bottom of the rotor core 100 can be easily distinguished. Thus, the rotor core 100 can be placed in the jig 200 with the layer at one axial AD end of the rotor core 100 facing up. As a result, the magnet 11 can be attached to the rotor core 100 from the sag P1 side. Therefore, chipping of the magnet 11 can be suppressed.

[0072] Next, rotor core 100 and magnet 11 are removed from jig 200. Then, rotor core 100 and magnet 11 are placed on lower die 310 (see FIG. 9). Thereafter, upper die 320 (see FIG. 9) is lowered until it contacts lower die 310, thereby performing die clamping. As shown in FIG. 9, lower die 310 has a plurality of support pins 311 that support the lower surface of magnet 11, and a plurality of support pins 312 that support the lower surface of rotor core 100. Support pins 311 are arranged at positions corresponding to lower hole 12c. Support pins 312 are arranged at positions corresponding to lower hole 12d.

[0073] Upper mold 320 has a plurality of press pins 321 that press the upper surface of magnet 11, and a plurality of press pins 322 that press the upper surface of rotor core 100. Press pins 321 are disposed at positions corresponding to upper holes 12a. Press pins 322 are disposed at positions corresponding to upper holes 12b. Upper mold 320 also has a gate 323. Gate 323 is an injection port through which resin is injected.

[0074] Next, resin is injected from gate 323. Thus, resin portion 12 is formed around rotor core 100 and magnet 11. Thereafter, upper die 320 is elevated, and support pins 311 and 312 are elevated as well. As support pins 311 and 312 are elevated, rotor core 100 and magnet 11 covered with resin portion 12 are removed from lower die 310. That is, support pins 311 and 312 function as ejector pins. In this manner, rotor core 100 shown in FIG. 8 is manufactured.

[0075] Hereinafter, first to third modified examples of this embodiment will be described with reference to Figures 12 to 14. Below, differences from this embodiment shown in Figures 1 to 11 will be mainly described.

[0076] (First Modification) A first modified example of the embodiment of the present invention will be described with reference to Fig. 12. Fig. 12 is a plan view showing the structure of the second plate member 102 of the first modified example of the embodiment. In the first modified example, an example in which the second plate member 102 has a recess 121b will be described.

[0077] As shown in Fig. 12, in the first modified example of this embodiment, the end portion on the inner side in the radial direction RD of the second plate member 102 has a recess 121b recessed outward in the radial direction RD. In other words, the end portion on the inner side in the radial direction RD of the second steel plate SP2 has a recess 121b recessed outward in the radial direction RD. Therefore, the magnetic flux of the magnet 11 (arrow in Fig. 12) flows outward in the radial direction RD so as to avoid the recess 121b. As a result, the magnetic flux of the magnet 11 can be further prevented from flowing inward in the radial direction RD. In addition, the recess 121b is separated from the hole 121a. Note that the recess 121b may extend to the hole 121a and be connected to the hole 121a.

[0078] (Second Modification) A second modified example of the embodiment of the present invention will be described with reference to Fig. 13. Fig. 13 is a plan view showing the structure of a first plate member 101 and a second plate member 102 of the second modified example of the present embodiment. In the second modified example, an example will be described in which an end 121c on the inner side in the radial direction RD of the second plate member 102 is disposed on the outer side in the radial direction RD compared to an end 121d on the inner side in the radial direction RD of the first plate member 101.

[0079] As shown in FIG. 13, in the second modified example of the present embodiment, the length of the second plate member 102 along the radial direction RD is shorter than the length of the first plate member 101 along the radial direction RD. The end 121c on the inner side of the radial direction RD of the second plate member 102 is disposed on the outer side of the radial direction RD compared to the end 121d on the inner side of the radial direction RD of the first plate member 101. In other words, the end 121c on the inner side of the radial direction RD of the second steel plate SP2 is disposed on the outer side of the radial direction RD compared to the end 121d on the inner side of the radial direction RD of the first core magnetic pole portion SP121a of the first steel plate SP1. Therefore, it is possible to further suppress the magnetic flux of the magnet 11 from flowing to the inner side of the radial direction RD of the second steel plate SP2. Note that, although the second plate member 102 has the recess 121b in FIG. 13, the recess 121b may not be included.

[0080] (Third Modification) A third modified example of the embodiment of the present invention will be described with reference to Fig. 14. Fig. 14 is a plan view showing the structure of a first plate member 101 and a second plate member 102 of the third modified example of the present embodiment. In the third modified example, an example in which a radial protrusion 161 is formed in a core central portion 111 will be described.

[0081] 14, in the third modified example of the present embodiment, the first plate member 101 further has a radial protruding portion 161 that protrudes outward in the radial direction RD from the core central portion 111. In other words, the first steel plate SP1 further has a radial protruding portion 161 that protrudes outward in the radial direction RD from the first core central portion SP111a. Therefore, the radial protruding portion 161 can restrict the movement of the magnet 11 inward in the radial direction RD.

[0082] In the third modified example, the first plate member 101 does not have the inner circumferential protruding portion 141, but may have both the radial protruding portion 161 and the inner circumferential protruding portion 141. Although not shown, the third steel plate SP3 and the fifth steel plate SP5 may also have the radial protruding portion 161 like the first steel plate SP1.

[0083] The above describes the embodiments of the present invention (including modified examples) with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various aspects without departing from the gist of the present invention. In addition, various inventions can be formed by appropriately combining multiple components invented in the above embodiments. For example, some components may be deleted from all components shown in the embodiments. For example, components across different embodiments may be appropriately combined. The drawings are mainly shown schematically for each component to make it easier to understand, and the thickness, length, number, spacing, etc. of each component shown in the drawings may differ from the actual ones due to the convenience of drawing. In addition, the material, shape, dimensions, etc. of each component shown in the above embodiments are only examples and are not particularly limited, and various modifications are possible within a range that does not substantially deviate from the effects of the present invention.

[0084] For example, in the embodiment shown in Fig. 1 to Fig. 14, an example is shown in which the first plate member 101 has two core magnetic pole portions 121, but the present invention is not limited to this. For example, the first plate member 101 may have one or three or more core magnetic pole portions 121. In other words, for example, the first steel plate SP1 may have one or three or more first core magnetic pole portions SP121a. Furthermore, the third steel plate SP3 may have one or three or more third core magnetic pole portions SP121c.

[0085] 1 to 14 show an example in which the number of holes 121a in core magnetic pole portions 121 at one axial AD end of rotor core 100 is different from the number of holes 121a in core magnetic pole portions 121 at the other axial AD end of rotor core 100, but the present invention is not limited to this. The number of holes 121a in core magnetic pole portions 121 at one axial AD end of rotor core 100 may be the same as the number of holes 121a in core magnetic pole portions 121 at the other axial AD end of rotor core 100.

[0086] 1 to 14, an example has been shown in which rotor core 100 includes third plate member 103, but the present invention is not limited to this. For example, rotor core 100 does not have to include third plate member 103. In other words, rotor core 100 does not have to include fifth steel plate SP5. [Industrial Applicability]

[0087] The present invention can be used in, for example, rotors and motors. [Explanation of symbols]

[0088] 1: Motor 10: Rotor 11: Magnet 12: Resin part 20: Stator 100: Rotor core 121: Core magnetic pole part 121a :hole 121b: recess 121c: End (radially inner end of the second steel plate) 121d: End (the radially inner end of the first core magnetic pole part of the first steel plate) 131: Core connection part 141: Inner circumferential protrusion (circumferential protrusion) 161: Radial protrusion AD: Axial direction AX: Central axis CD: Circumferential direction L1~L5: layer RD: Radial direction SP1: 1st steel plate SP111a: Center of the first core SP111b: Center of the second core SP111c: Center of the 3rd core SP121a: First core pole part SP121b: Second core pole part SP121c: 3rd core pole part SP121d: 4th core magnetic pole part SP121e: 5th core pole part SP2: 2nd steel plate SP3: 3rd steel plate SP4: 4th steel plate SP5: 5th steel plate

Claims

1. A plurality of magnets arranged in a circumferential direction around a central axis extending vertically; Rotor core and having The rotor core is a laminate in which steel plates are laminated in the axial direction, At least one layer of the rotor core includes a first steel plate and a plurality of second steel plates; The first steel plate, in the one layer, A first core central portion; a first core magnetic pole portion disposed radially outward of the first core central portion and connected to the first core central portion; having The second steel plate has a second core pole portion disposed in a circumferential direction radially outward of the first core central portion in the one layer, and disposed without being connected to the first core central portion via a gap by a steel plate material, A rotor having a resin portion that covers at least a portion of the rotor core and the periphery of the plurality of magnets in a cross section passing through the central axis.

2. The rotor core has a third steel plate and a plurality of fourth steel plates in a layer different from the at least one layer, The third steel plate is A second core central portion; a third core magnetic pole portion disposed radially outward of the second core central portion; having the fourth steel plate is disposed radially outward of the second core central portion in a circumferential direction and has a fourth core magnetic pole portion disposed with a gap between it and the second core central portion, The rotor according to claim 1 , wherein the first core pole portion is arranged circumferentially shifted from the third core pole portion.

3. The first steel plate has a plurality of the first core pole portions, The rotor according to claim 1 or 2, wherein the plurality of first core magnetic pole portions are connected to the first core central portion at equal intervals in the circumferential direction.

4. The rotor core has a fifth steel plate in a layer different from the at least one layer, The fifth steel plate is A third core central portion; a fifth core magnetic pole portion disposed radially outward of the third core central portion; having The number of the fifth core magnetic pole parts is the same as the number of poles, The rotor according to claim 1 , wherein all of the fifth core pole portions are connected to the third core central portion.

5. The rotor according to claim 4 , wherein the fifth steel plates are arranged on both axial ends of the rotor core.

6. The rotor according to claim 1 , wherein the first steel plate further has a core connecting portion that connects the first core pole portion and the first core central portion.

7. The rotor according to claim 6 , wherein the first steel plate further has a circumferential protruding portion that protrudes in the circumferential direction from the core connecting portion.

8. The rotor according to claim 6 , wherein the first steel plate further has a radial protruding portion that protrudes radially outward from the first core central portion.

9. The rotor according to claim 1 , wherein a radially inner end of the second steel plate has a recess that is recessed radially outward.

10. 10. The rotor according to claim 1, wherein a radially inner end of the second steel plate is positioned radially outward compared to a radially inner end of the first core pole portion of the first steel plate.

11. The rotor according to claim 1 , wherein the resin portion covers a periphery of the rotor core in a cross section passing through the central axis, except for a periphery of a through hole of the rotor core and an outer circumferential surface of the rotor core.

12. the rotor core has a plurality of steel plates including the first steel plate and the second steel plate, the plurality of steel plates have a plurality of core pole portions including the first core pole portion and the second core pole portion, Each of the core pole portions has at least one hole passing therethrough in the axial direction, the holes of the core magnetic pole portions are continuous with holes of other core magnetic pole portions adjacent in the axial direction, The rotor according to claim 1 , wherein a portion of the resin portion is disposed inside the hole.

13. The rotor according to claim 12 , wherein the number of holes in the core pole portion at one axial end of the rotor core is different from the number of holes in the core pole portion at the other axial end of the rotor core.

14. A rotor according to any one of claims 1 to 13 and a stator, A motor, wherein the stator is disposed radially outward of the rotor.

Images