Stator and motor

Abstract

To provide a stator that can make a motor demonstrate good performance and the motor that can demonstrate good performance.SOLUTION: A stator 30 comprises multiple magnetic materials 90 that include an inner peripheral part 91a and multiple protrusions 96 extending inside from the inner peripheral part 91a. The multiple magnetic materials 90 comprise a first magnetic material 94 and a second magnetic material 97 that overlap each other in the axial direction. The positions of the multiple protrusions 96 of the first magnetic material 94 are different from those of the multiple protrusions 96 of the second magnetic material 97 in the circumferential direction. A motor 1 comprises the stator 30 and a rotor 40.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a stator and a motor.

Background Art

[0002] Conventionally, laminated electromagnetic steel sheets have been clamped and integrated. Such integration is generally performed by clamping the tooth portions of each of the plurality of laminated electromagnetic steel sheets, for example, as described in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the teeth are the portions through which the magnetic flux generated by the coil passes. If there are portions clamped in such portions, the magnetic flux passing through the teeth will be affected, and as a result, the performance of the motor may be affected.

[0005] Therefore, one of the problems of the present invention is to provide a stator and a motor that can enable the motor to exhibit good performance.

Means for Solving the Problems

[0006] The stator according to the present invention includes a plurality of magnetic bodies having an inner peripheral portion and a plurality of protruding portions extending inward from the inner peripheral portion. The plurality of magnetic bodies include a first magnetic body and a second magnetic body that overlap in the axial direction. In the circumferential direction, the positions of the plurality of protruding portions of the first magnetic body are different from the positions of the plurality of protruding portions of the second magnetic body.

[0007] Note that the plurality of magnetic bodies include a plurality of first magnetic bodies including the first magnetic body and a plurality of second magnetic bodies including the second magnetic body. In the axial direction, the plurality of first magnetic bodies including the first magnetic body and the plurality of second magnetic bodies including the second magnetic body are stacked. In the axial direction, the plurality of protrusions of the plurality of first magnetic bodies face each other. In the axial direction, the plurality of protrusions of the plurality of second magnetic bodies may face each other.

[0008] Further, the inner peripheral surface of the protrusion may be a cut surface.

[0009] Also, in the axial direction, there is a gap between the plurality of protrusions of the plurality of first magnetic bodies facing each other. In the axial direction, there may be a gap between the plurality of protrusions of the plurality of second magnetic bodies facing each other.

[0010] Further, the magnetic body includes a ring having the inner peripheral portion, a plurality of magnetic pole portions, and a plurality of plate-like portions connecting the ring and the plurality of magnetic pole portions. In the circumferential direction, the width of the protrusion may be smaller than the width of the plate-like portion.

[0011] Also, in the circumferential direction, a portion of the inner peripheral portion of the ring corresponding to the plate-like portion has a recess, and the protrusion may be inside the recess.

[0012] The motor according to the present invention includes the above-described motor and a rotor.

Brief Description of Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0014] Hereinafter, modes for implementing the stator and the motor according to the present invention are illustrated together with the accompanying drawings. The embodiments illustrated below are for facilitating the understanding of the present invention and are not for limiting the interpretation of the present invention. The present invention can be changed and improved from the following embodiments without departing from the gist thereof. Further, in the above accompanying drawings, for ease of understanding, the dimensions of each member may be shown exaggerated or reduced, or hatching or the like may be omitted.

[0015] (First Embodiment) FIG. 1 is a perspective view showing an example of the motor 1 in the embodiment, and is a perspective view seen from one side in the direction of the rotation axis of the motor 1. Hereinafter, the direction of the rotation axis of the motor 1 will be referred to as the "axial direction", and the direction that intersects the rotation axis of the motor 1 and is perpendicular to the axial direction will be referred to as the "radial direction". FIG. 2 is a cross-sectional view in the axial direction of the motor 1. In the present embodiment, the motor 1 is configured as a so-called outer rotor type brushless motor. However, the motor to which the present invention is applied is not limited to an outer rotor type brushless motor.

[0016] As shown in FIGS. 1 and 2, the motor 1 mainly includes a housing 10, a shaft 20 (rotation axis), bearings 21 and 22, a stator 30, and a rotor 40. The shaft 20 includes one end 20a and the other end 20b. FIG. 1 is a view seen from the side of one end 20a of the shaft 20.

[0017] The housing 10 includes a base 12 that forms the bottom of the housing 10 and a frame 11 that forms the side surface and the top surface of the housing 10. The base 12 is disposed on the other side in the axial direction (the side of the other end 20b of the shaft 20).

[0018] In some cases, the side of one end 20a of the shaft 20 (one side in the axial direction) may be described as "up", "upper side", "above", etc., and the side of the other end 20b of the shaft 20 (the other side in the axial direction) may be described as "down", "lower side", "below", etc.

[0019] The base 12 is a disc-shaped member and is arranged perpendicular to the longitudinal direction (axial direction) of the shaft 20. That is, the base 12 extends in the radial direction of the motor 1. In the radial direction, the side closer to the shaft 20 is referred to as the "inner side", and the side farther from the shaft 20 is referred to as the "outer side". A cylindrical tubular portion 13 extending along the axial direction is integrally formed with the base 12 on the central side of the base 12. That is, the housing 10 includes the tubular portion 13. Further, a hole through which the shaft 20 passes is formed on the side (inner side) of the shaft 20 with respect to the inner peripheral surface 13a of the tubular portion 13. Electronic components such as capacitors and resistor elements are mounted on the surface (upper surface) on one end portion 20a side of the base 12, and a substrate (hereinafter referred to as a circuit board) 15 having wirings and terminals is placed thereon. A recess 12a is formed in a part of the base 12, and the base 12 has an opening due to this recess 12a. A connector 16 electrically connected to an external device is arranged in this opening. An electric current is supplied from the outside to a coil 33 (described later) of the stator 30 via the connector 16, the circuit board 15, and connection terminals provided on the stator 30.

[0020] The frame 11 has a cylindrical first cylindrical portion (hereinafter referred to as a large-diameter cylinder) 11A, a disc-shaped top surface portion (hereinafter referred to as a disc portion) 11B, and a cylindrical second cylindrical portion (hereinafter referred to as a small-diameter cylinder) 11C having an outer shape smaller than that of the large-diameter cylinder 11A. The large-diameter cylinder 11A is fixed to the outer peripheral portion of the base 12 and extends generally upward from the position of the base 12 in the axial direction. The disc portion 11B extends in the radial direction and extends from the upper end of the large-diameter cylinder 11A toward the shaft 20. The small-diameter cylinder 11C extends upward from the inner peripheral portion 11B1 of the disc portion 11B. A through hole 11C2 is formed on the inner side with respect to the inner peripheral surface 11C1 of the small-diameter cylinder 11C. In this embodiment, the large-diameter cylinder 11A, the disc portion 11B, and the small-diameter cylinder 11C are integrally formed.

[0021] Inside the housing 10 having such a configuration, the shaft 20, the bearings 21, 22, the stator 30, the rotor 40, etc. are accommodated.

[0022] The bearing 21 is disposed inside the small-diameter cylinder 11C, and the outer peripheral surface 21a of the bearing 21 is fixed to the inner peripheral surface 11C1 of the small-diameter cylinder 11C. The bearing 22 is disposed inside the inner peripheral surface 13a of the cylindrical portion 13, and the outer peripheral surface of the bearing 22 is fixed to the inner peripheral surface 13a of the cylindrical portion 13. Examples of the bearings 21 and 22 include ball bearings and sleeve bearings. A stepped portion 13b is formed on the inner peripheral surface 13a of the cylindrical portion 13. In the axial direction, the bearing 22 is supported by this stepped portion 13b. The outer peripheral surface of the shaft 20 is supported by the inner peripheral surfaces of the bearing 21 and the bearing 22. Thus, the bearings 21 and 22 rotatably support the shaft 20. One end 20a (upper end) of the shaft 20 projects upward through the disk portion 11B, and the other end 20b (lower end) of the shaft 20 is located inside the cylindrical portion 13.

[0023] The rotor 40 has a holder 41 and a magnet 44. The holder 41 is formed of a magnetic material and has a cylindrical tube portion 43 and an annular portion 42 extending inward from the upper end of the tube portion 43. The annular portion 42 is integrally formed with the tube portion 43. The annular portion 42 is annular when viewed from above and has an inner peripheral portion 42a. The shaft 20 passes through the inner peripheral portion 42a of the annular portion 42 and is fixed to the inner peripheral surface of this inner peripheral portion 42a. Therefore, the holder 41 and the shaft 20 rotate integrally. Also, in the radial direction, a spacer 71, a ring 72, and a second ring 73 having an outer shape (or outer diameter) smaller than that of the spacer 71 or the ring 72 are arranged between the inner peripheral portion 42a of the annular portion 42 and the shaft 20. The tube portion 43 extends downward from the outer peripheral portion 42b of the annular portion 42. In the axial direction, the lower end portion of the tube portion 43 is located below the lower end portion of a stator core 37 of the stator 30 described later. The magnet 44 has an annular shape and is fixed to substantially the entire inner peripheral surface of the tube portion 43. The lower end portion of the magnet 44 is located below the lower end portion of the tube portion 43. Also, in this magnet 44, a plurality of different magnetic poles (N poles and S poles) are alternately formed along the circumferential direction. In the radial direction, the magnet 44 faces the stator core 37 of the stator 30 with an air gap G therebetween.

[0024] Note that the configurations of the housing 10, the shaft 20, the bearings 21, 22, the rotor 40, etc. described above are exemplary and are not limited to the configurations described above.

[0025] Next, the stator 30 of the motor 1 will be described in detail.

[0026] As shown in FIG. 2, the stator 30 is fixed to the housing 10. Specifically, in the present embodiment, the stator 30 is fixed to the cylindrical portion 13 of the housing 10. The stator 30 includes a stator core 37, an insulator 34 formed of an insulating member such as resin, and a plurality of coils 33. The insulator 34 surrounds most of the stator core 37. The stator core 37 is fixed to the cylindrical portion 13. The stator core 37 may be fixed to the cylindrical portion 13 by adhesion, press-fitting, or other methods.

[0027] FIG. 3 is a perspective view showing the stator core 37 of the stator 30, showing the stator core 37 from which the plurality of coils 33 and the insulator 34 have been removed. FIG. 4 is a plan view of the stator core 37 shown in FIG. 3 (viewed from above in the axial direction). FIG. 5 is a view showing a part of the cross-section along the line A-A (cross-section along the axial direction) shown in FIG. 4. As described above, the stator core 37 is fixed to the cylindrical portion 13. In FIG. 4, the cylindrical portion 13 to which the stator core 37 is fixed is shown by a dashed line.

[0028] As shown in FIGS. 3 to 5, the stator core 37 is formed by a plurality of magnetic bodies 90 stacked in the axial direction (hereinafter sometimes referred to as the "magnetic body group 90G"). Therefore, the stator 30 includes a plurality of magnetic bodies 90. Each of the plurality of magnetic bodies 90 constituting the magnetic body group 90G may be formed of the same material, or may be, for example, an electromagnetic steel sheet having substantially the same shape and dimensions. In the present specification, "substantially the same" and "substantially the same" etc. may include differences due to manufacturing errors etc. within a generally recognized range.

[0029] The stator core 37 (magnetic body group 90G) formed by a plurality of magnetic bodies 90 includes an annular (circular annular in this embodiment) ring 31 located on the inner side in the radial direction, a plurality of plate-like portions 32 radially extending outward from the ring 31, and a magnetic pole portion 35 connected to the outer end portion of each of the plurality of plate-like portions 32. That is, each of the plurality of magnetic bodies 90 constituting the magnetic body group 90G includes an annular (circular annular in this embodiment) ring 91 located on the inner side in the radial direction, a plurality of plate-like portions 92 radially extending from the ring 91, and a magnetic pole portion 95 connected to the outer end portion of each of the plurality of plate-like portions 92. In each of the plurality of magnetic bodies 90, the plate-like portion 92 connects the ring 91 and the magnetic pole portion 95. Also, a so-called tooth (outer shape) is formed by the plate-like portion 92 and the magnetic pole portion 95.

[0030] Note that flat and continuous surfaces are formed in the radial direction and the circumferential direction on the ring 31 of the stator core 37 (that is, the ring 91 of each of the plurality of magnetic bodies 90), the plate-like portion 32 of the stator core 37 (that is, the plate-like portion 92 of each of the plurality of magnetic bodies 90), and the magnetic pole portion 35 of the stator core 37 (that is, the magnetic pole portion 95 of each of the plurality of magnetic bodies 90).

[0031] The ring 31 of the stator core 37 is formed in a cylindrical shape (circular cylindrical shape in this embodiment) and has a cylindrical inner peripheral portion 31a (inner peripheral surface). The inner peripheral portion 31a includes the inner peripheral portion 91a (inner peripheral surface) of each of the plurality of magnetic bodies 90 stacked in the axial direction. Inside the inner peripheral portion 31a in the radial direction is a through hole (hole portion) 31h that penetrates the stator core 37 in the axial direction. As shown in FIGS. 2 and 4, the upper portion of the above-described cylindrical portion 13 is disposed in approximately the lower half of this through hole 31h, and approximately the lower half portion of the inner peripheral portion 31a of the ring 31 is fixed to the outer peripheral surface 13e of the upper portion of the cylindrical portion 13. In this way, the stator core 37 is fixed to and supported by the cylindrical portion 13 of the housing 10. Also, the shaft 20 passes through the inside of this through hole 31h.

[0032] As shown in FIGS. 3 and 4, the plurality of plate-like portions 32 of the stator core 37 are arranged at a predetermined interval (equal intervals in the embodiment) in the circumferential direction of the ring 31. When viewed from the axial direction, the plate-like portion 32 has a substantially rectangular plate-like shape. On the other hand, each of the plurality of magnetic pole portions 35 has a length larger than that of the plate-like portion 32 in the circumferential direction and has a flat fan-shaped shape. The plurality of magnetic pole portions 35 are separated from each other in the circumferential direction, and when viewed from the axial direction, a substantially circular locus is drawn by the outer peripheral surface 35of of the plurality of magnetic pole portions 35.

[0033] From the inner peripheral portion 31a of the stator core 37, a plurality of protrusions 36 protrude radially inward. That is, the stator core 37 (the plurality of magnetic bodies 90) has the plurality of protrusions 36. In the present embodiment, the plurality of protrusions 36 have six protrusions 36 when viewed from the axial direction. The six protrusions 36 are arranged at substantially equal intervals (that is, at intervals of 60°) in the circumferential direction and have substantially the same shape and dimensions except for their positions in the circumferential direction. Further, looking at each of the six protrusions 36, as shown in FIG. 4, when viewed from the axial direction, the plate-like portion 32 and the magnetic pole portion 35 are arranged on a straight line La extending in the radial direction through the center C of the stator core 37 (the center C of the shaft 20) and the protrusion 36. Furthermore, each of the protrusion 36, the plate-like portion 32, and the magnetic pole portion 35 has a shape that is substantially line-symmetrical with respect to the straight line La.

[0034] Each of the plurality of magnetic bodies 90 forming the stator core 37 has, in addition to the above-described ring 91 corresponding to the ring 31, the above-described plate-like portion 92 corresponding to the plate-like portion 32, the above-described magnetic pole portion 95 corresponding to the magnetic pole portion 35, and a protrusion 96 corresponding to the protrusion 36.

[0035] Note that the number of the magnetic pole portions 35, the plate-like portions 32, and the protrusions 36 when viewed from the axial direction is not limited to six. Also, the number of the magnetic pole portions 35 and the plate-like portions 32 when viewed from the axial direction does not have to be the same as the number of the protrusions 36 when viewed from the axial direction.

[0036] As shown in FIGS. 3 and 4, the six protrusions 36 include three first protrusions 38 and three second protrusions 39. The three first protrusions 38 are three protrusions 36 arranged at intervals of 120°. The three second protrusions 39 are three protrusions 36 located at positions rotated 60° with respect to the three first protrusions 38. In the present embodiment, as shown in FIG. 5, in the axial direction, a magnetic body 90 having a protrusion 96 forming the first protrusion 38 (hereinafter sometimes referred to as the "first protrusion 98") (hereinafter sometimes referred to as the "first magnetic body 94") and a magnetic body 90 having a protrusion 96 forming the second protrusion 39 (hereinafter sometimes referred to as the "second protrusion 99") (hereinafter sometimes referred to as the "second magnetic body 97") are alternately stacked in the axial direction. Focusing on the first magnetic body 94 and the second magnetic body 97 adjacent to each other in the axial direction, in the present embodiment, the first magnetic body 94 is above the second magnetic body 97. However, the positional relationship between the first magnetic body 94 and the second magnetic body 97 may be reversed (the first magnetic body 94 is below and the second magnetic body 97 is above).

[0037] As shown in FIGS. 3 and 5, the first magnetic body 94 has three first protrusions 98. The three first protrusions 98 of each of the plurality of first magnetic bodies 94 are stacked with a gap approximately equal to the thickness of one magnetic body 90 in the axial direction, forming three first protrusions 38. Therefore, focusing on each of the three first protrusions 38, in the axial direction, the plurality of first protrusions 38 face each other. Further, the second magnetic body 97 has three second protrusions 99. The three second protrusions 99 of each of the plurality of second magnetic bodies 97 are stacked with a gap approximately equal to the thickness of one magnetic body 90 in the axial direction, forming three second protrusions 39. Therefore, focusing on each of the three second protrusions 39, in the axial direction, the plurality of second protrusions 39 face each other. In the circumferential direction, the position of the second protrusion 99 is different from the position of the first protrusion 98. Specifically, the second protrusion 99 is at a position rotated 60° with respect to the first protrusion 98. That is, in the circumferential direction, the positions of the plurality of protrusions 96 (the plurality of first protrusions 98) of the first magnetic body 94 are different from the positions of the plurality of protrusions 96 (the plurality of second protrusions 99) of the second magnetic body 97.

[0038] Also, as shown in FIG. 5, the stator core 37 formed from a plurality of magnetic bodies 90 (magnetic body group 90G) includes a plurality of first magnetic bodies 94 (first magnetic body group) and a plurality of second magnetic bodies 97 (second magnetic body group). In the axial direction, the plurality of first magnetic bodies 94 (first magnetic body group) and the plurality of second magnetic bodies 97 (second magnetic body group) are stacked. In the axial direction, the plurality of protrusions 96 (plurality of first protrusions 98) of the plurality of first magnetic bodies 94 face each other, and in the axial direction, the plurality of protrusions 96 (plurality of second protrusions 99) of the plurality of second magnetic bodies 97 face each other. Specifically, as described above, the first protrusions 98 of a pair of adjacent first magnetic bodies 94 in the axial direction of the first magnetic body group face each other with a gap approximately equal to the thickness (axial length) of one magnetic body 90 (one second magnetic body 97). Also, the second protrusions 99 of a pair of adjacent second magnetic bodies 97 in the axial direction of the second magnetic body group face each other with a gap approximately equal to the thickness (axial length) of one magnetic body 90 (one first magnetic body 94). That is, in the axial direction, there is a gap Gp1 with a length substantially equal to the axial thickness of one magnetic body 90 between the mutually adjacent first protrusions 98, 98, and there is also a gap Gp2 with a length substantially equal to the thickness of one magnetic body 90 between the mutually adjacent second protrusions 99, 99.

[0039] As shown in FIG. 5, the inner peripheral side end faces 96E (inner peripheral surfaces) of the respective plurality of protrusions 96 are cut surfaces for reasons described later. Also, the ends of the protrusions including the end faces 96E (inner peripheral surfaces) are curved and descend as going inward in the radial direction.

[0040] In the present embodiment, as shown in FIG. 4, in the circumferential direction, the width W1 of each of the plurality of (three) protrusions 96 of one magnetic body 90 is smaller than the width W2 of each of the plurality of (three) plate-like portions 92 of one magnetic body 90. That is, in the circumferential direction, the width W1 of each of the plurality of protrusions 36 of the magnetic body group 90G is smaller than the width W2 of each of the plurality of plate-like portions 32 of the magnetic body group 90G.

[0041] As shown in FIG. 2, the insulator 34 surrounds most of the stator core 37 as described above. In this embodiment, the insulator 34 covers the outer portion of the ring 31, the entire plate-like portion 32, and the portion of the magnetic pole portion 35 excluding the outer peripheral surface 35a of the magnetic pole portion 35. That is, the plate-like portion 32 and most of the magnetic pole portion 35 are accommodated in the insulator 34, and the outer peripheral surface 35a of the magnetic pole portion 35 is exposed from the insulator 34. The outer peripheral surface 35a exposed from the insulator 34 and the magnet 44 of the rotor 40 face each other in the radial direction via the air gap G so that a magnetic circuit is formed in the motor 1.

[0042] As shown in FIG. 2, the plurality of coils 33 are wound around each of the plurality of plate-like portions 32 via the insulator 34. In this way, insulation is provided between the plurality of coils 33 and the stator core 37. When current from an external power source flows through the plurality of coils 33 via the connector 16 and the circuit board 15, magnetic lines of force pass through the ring 31, the plate-like portion 32, and the magnetic pole portion 35 of the stator core 37, and a magnetic circuit is formed in the motor 1. As a result, the rotor 40 located outside the stator 30 rotates with respect to the stator 30 about the shaft 20.

[0043] The stator 30 in this embodiment includes the stator core 37 as described above, and this stator core 37 has a plurality of protruding portions 36 extending inward from the inner peripheral portion 31a. Therefore, as shown in FIG. 4, a gap Gs is formed between the cylindrical portion 13 of the housing 10 and the inner peripheral portion 31a of the stator core 37 by the plurality of protruding portions 36. Therefore, when the stator core 37 is adhered to the cylindrical portion 13, it is easy to provide an adhesive in this gap Gs, and the stator 30 and the cylindrical portion 13 can be firmly fixed by filling the gap Gs with the adhesive.

[0044] Also, in the present embodiment, as described above, in the circumferential direction, the positions of the plurality of protrusions 96 (the plurality of first protrusions 98) of the first magnetic body 94 are different from the positions of the plurality of protrusions 96 (the plurality of second protrusions 99) of the second magnetic body 97. According to such a configuration, for the reasons described later, the ring 31, the plate-like portion 32, and the magnetic pole portion 35 of the stator core 37, which are the portions through which the magnetic flux passes, can have flat and continuous surfaces. Therefore, the continuous surfaces of the plurality of stacked magnetic bodies 94 can be brought into contact with a relatively large area. Thus, according to the stator 30 in the present embodiment, a path through which the magnetic flux passing through the ring 31, the plate-like portion 32, and the magnetic pole portion 35 can pass can be ensured. Also, the performance of the motor 1 can be improved (for example, the output of the motor can be improved). That is, the stator 30 of the present embodiment can enable the motor 1 to exhibit good performance, and the motor 1 including such a stator 30 can exhibit good performance.

[0045] Next, an example of a method for manufacturing the stator 30 will be described.

[0046] First, as shown in FIG. 6, a plurality of magnetic plates 500 (electromagnetic steel sheets) having a predetermined shape are prepared (preparation step). This magnetic plate 500 has the same configuration as the above-described magnetic body 90 except for having a central portion 510. Therefore, the magnetic plate 500 is formed of the same material as the magnetic body 90 (each electromagnetic steel sheet forming the magnetic body group 90G) and includes a ring 91, an inner peripheral portion 91a, a plate-like portion 92, a magnetic pole portion 95, and the like.

[0047] The central portion 510 of the magnetic plate 500 is located radially inside the inner peripheral portion 91a and is provided on the central side in the radial direction of the magnetic plate 500. The central portion 510 includes a portion on the inner side in the radial direction (hereinafter referred to as the "inner portion") 512 and a plurality of spokes 511 that radially extend outward from the inner portion 512. In the present embodiment, the inner portion 512 is ring-shaped and annular, but the shape of the inner portion 512 is not limited to this. In the present embodiment, the number of the plurality of spokes 511 is three, but the number of the plurality of spokes 511 is not limited to three.

[0048] Each of the plurality of (three) spokes 511 extends radially and is connected to the ring 91. That is, the plurality of spokes 511 connect the inner portion 512 and the ring 91. The plurality of (three) spokes 511 are arranged at substantially equal intervals (i.e., at intervals of 120°) in the circumferential direction. Focusing on one spoke 511, the spoke 511, the plate-like portion 92, and the magnetic pole portion 95 are arranged in a line on a straight line La extending radially through the center of the spoke 511 in the circumferential direction. The spoke 511, the plate-like portion 92, and the magnetic pole portion 95 are formed substantially symmetrically with respect to the straight line La. In the present embodiment, in the circumferential direction, the width W1 of the spoke 511 is smaller than the width W2 of the plate-like portion 92.

[0049] On the other hand, focusing on each of the plurality of plate-like portions 92, the plurality of plate-like portions 92 include a spoke 511 on the straight line La extending radially through the plate-like portion 92, a plate-like portion 92 connected to the spoke 511 (hereinafter sometimes referred to as "first plate-like portion 92A"), and a plate-like portion 92 on the straight line La extending radially through the plate-like portion 92 and at a different position from the spoke 511 in the circumferential direction (hereinafter sometimes referred to as "second plate-like portion 92B").

[0050] In this embodiment, as shown in FIG. 6, a magnetic plate 500 (hereinafter sometimes referred to as "magnetic plate 500A") is rotated by a predetermined angle with respect to a magnetic plate 500 (hereinafter sometimes referred to as "magnetic plate 500B") stacked directly above it, and then stacked (trans-stacked). In a pair of adjacent magnetic plates 500, 500 in the axial direction, the lower magnetic plate 500 is the magnetic plate 500A, and the upper magnetic plate 500 is the 500B. In this embodiment, after rotating the magnetic plate 500B by 60° with respect to the magnetic plate 500A, the magnetic plate 500B is stacked directly above the magnetic plate 500A. Therefore, in a pair of magnetic plates 500A, 500B where the magnetic plate 500B is stacked on the magnetic plate 500A, the spoke 511 of the magnetic plate 500B (hereinafter sometimes referred to as "spoke 511B") is at a position shifted by 60° with respect to the spoke 511 of the magnetic plate 500A (hereinafter sometimes referred to as "spoke 511A"), the first plate-shaped portion 92A of the magnetic plate 500B is at a position shifted by 60° with respect to the first plate-shaped portion 92A of the magnetic plate 500A, and the second plate-shaped portion 92B of the magnetic plate 500B is at a position shifted by 60° with respect to the second plate-shaped portion 92B of the magnetic plate 500A.

[0051] When the number of prepared magnetic plates 500 is N (N is a natural number of 2 or more), such trans-stacking is repeated (N - 1) times (trans-stacking process). In this embodiment, for convenience of explanation, N is an even number. FIG. 7 is a perspective view showing a laminate 550 formed by the trans-stacking process. FIG. 8 is a cross-sectional view taken along line B - B shown in FIG. 7.

[0052] As shown in FIGS. 7 and 8, since the laminate 550 is formed by the above-described transfer lamination process, in the axial direction, the first magnetic plate 500A (lower side) and the second magnetic plate 500B (upper side) are alternately stacked from the lower side to the upper side. That is, as shown in FIG. 8, in a pair of adjacent first magnetic plates 500A, 500A in the axial direction among the plurality of first magnetic plates 500A, a gap Gp1 corresponding to the thickness of one second magnetic plate 500B is formed between the respective spokes 511A. Similarly, in a pair of adjacent second magnetic plates 500B, 500B in the axial direction, a gap Gp2 corresponding to the thickness of one first magnetic plate 500A is formed between the respective spokes 511B. On the other hand, in the axial direction, the inner portions 512 of the plurality of magnetic plates 500 are in contact with each other (substantially surface contact) and stacked. In the laminate 550, the stacked spokes 511A may be collectively referred to as a "group of spokes 511A", and the stacked spokes 511B may be collectively referred to as a "group of spokes 511B".

[0053] In the present embodiment, the inner portions 512 of the plurality of magnetic plates 500 constituting the laminate 550 are caulked (caulking step). Specifically, in the circumferential direction of the inner portion 512 of the magnetic plate 500 located at the uppermost side in the laminate 550 (the second magnetic plate 500B in the present embodiment), caulking jigs are applied at equal intervals (at intervals of 60° in the present embodiment), and the caulking jigs are pressed from the upper side toward the lower side. Thereby, the plurality of magnetic plates 500 constituting the laminate 550 are integrated via the caulked portions 515 of the inner portions 512. As described above, since the magnetic plate 500 has the same configuration as the above-described magnetic body 90 except for having the central portion 510, the laminate 550 formed by stacking the magnetic plates 500 also includes the ring 31, the inner peripheral portion 31a, the plurality of plate-like portions 32, and the plurality of magnetic pole portions 35. Further, in the laminate 550, the second magnetic plate 500B corresponds to the above-described first magnetic body 94, and the first magnetic plate 500A corresponds to the above-described second magnetic body 97.

[0054] After integrating the plurality of magnetic plates 500 of the laminate 550 by the clamping process, an insulator 34 (see FIG. 2) is attached to each of the plurality of plate-like portions 32 of the laminate 550, and further, a coil 33 (see FIG. 2) is wound around each of the attached plurality of insulators 34 (attachment process). By this attachment process, the plurality of magnetic plates 500 are further integrated by the wound coils 33.

[0055] After the attachment process, the plurality of (three in this embodiment) spoke 511A groups and the plurality of (three in this embodiment) spoke 511B groups of the laminate 550 are cut (cutting process). The cutting positions of the spoke 511A groups and the spoke 511B groups in the radial direction are not particularly limited, but it is preferable to cut the spoke 511A groups and the spoke 511B groups at positions near the inner peripheral portion 31a in each of the spoke 511A groups and the spoke 511B groups. In this embodiment, as described above, in the circumferential direction, the width W1 of the spoke 511 is smaller than the width W2 of the plate-like portion 92. Therefore, the spoke 511A groups and the spoke 511B groups can be easily cut.

[0056] The method of cutting the spoke 511A groups and the spoke 511B groups is not particularly limited. As one example, as shown in FIG. 9(A), the spoke 511A groups and the spoke 511B groups may be cut using a mold Mo. According to the cutting by the mold Mo, for example, the following cutting portions 511E and cut surfaces 511Ef are formed at the tips (end portions) of the respective spokes 511 of the spoke 511A groups and the tips (end portions) of the respective spokes 511 of the spoke 511B groups. That is, when the mold Mo is moved from the upper side to the lower side in the vertical direction, for example, to cut the spoke 511A groups and the spoke 511B groups, the cutting portion 511E has a shape that inclines downward as it goes from the outside to the inside in the radial direction, and the tip of the cutting portion 511E (cut surface 511Ef) is substantially parallel to the direction in which the mold is moved (vertical direction).

[0057] As another example, as shown in FIG. 9(B), the spokes 511A group and the spokes 511B group may be cut using the laser Lr. According to the cutting by the laser Lr, for example, the following cutting portions 511E and cut surfaces 511Ef are formed at the tips of the respective spokes 511 of the spokes 511A group and the tips of the respective spokes 511 of the spokes 511B group. That is, when the laser Lr is emitted, for example, from the upper side in the vertical direction downward to cut the spokes 511A group and the spokes 511B group, the cutting portion 511E has a shape that slopes downward as it goes from the outside to the inside in the radial direction, and the tip of the cutting portion 511E (cut surface 511Ef) is an inclined surface that slopes downward as it goes from the outside to the inside in the radial direction.

[0058] The end face 96E of each protruding portion 96 of the plurality of magnetic bodies 90 forming the stator core 37 may have a shape like the cut surface 511Ef shown in FIG. 9(A) or (B), and the end portion including the end face 96E in the protruding portion 96 may have a shape like the cutting portion 511E shown in FIG. 9(A) or (B).

[0059] By cutting the spokes 511A group and the spokes 511B group as described above, the central portion 510 of each magnetic plate 500 constituting the laminate 550 is removed except for the portion on the side connected to the inner peripheral portion 31a. Then, the remaining portion on the side connected to the inner peripheral portion 31a becomes the protruding portion 36 of the stator core 37 shown in FIG. 3 (the protruding portion 96 of each of the plurality of stacked magnetic bodies 90). Further, the protruding portion 36 (the protruding portion 96 of each of the plurality of stacked magnetic bodies 90) generated by cutting the spokes 511A group becomes the second protruding portion 39 (the second protruding portion 99 of each of the plurality of stacked second magnetic bodies 97), and the protruding portion 36 (the protruding portion 96 of each of the plurality of stacked magnetic bodies 90) generated by cutting the spokes 511B group becomes the first protruding portion 38 (the first protruding portion 98 of each of the plurality of stacked first magnetic bodies 94).

[0060] According to the present embodiment, the stator 30 can be manufactured by the above-described steps. According to such a method for manufacturing the stator 30, since the laminate 550 is formed by laminating the magnetic plates 500, in each of the spoke 511A group and the spoke 511B group of the laminate 550, between a pair of adjacent spokes 511, 511, intervals (gaps Gp1, Gp2) approximately equal to the thickness (length in the axial direction) of one magnetic plate 500 are formed. That is, according to the above-described steps, in each of the spoke 511A group and the spoke 511B group, it is possible to prevent a plurality of spokes 511 from being densely arranged in the axial direction. Therefore, by cutting the spoke 511A group and the spoke 511B group, it is possible to easily cut and remove each central portion 510 of the magnetic plates 500 stacked in the axial direction, and the stator 30 can be easily manufactured.

[0061] Further, according to this manufacturing method, in order to cut the central portion 510 in which the caulked portion 515 is formed, a portion through which magnetic flux passes in the stator core, such as a ring, a plate-like portion, and a magnetic pole portion, can be continuously formed of a magnetic material, and the stator core can be manufactured.

[0062] (Second Embodiment) Next, the stator according to the second embodiment will be described. The stator of the present embodiment is the same as the stator 30 of the first embodiment except that a part of the stator core is different from the stator core 37 according to the first embodiment. Therefore, hereinafter, for the present embodiment, only the configuration different from that of the first embodiment in the stator core will be described, and the other configurations will be denoted by the same reference numerals as those in the first embodiment and the description thereof will be omitted.

[0063] FIG. 10 is a perspective view showing a stator core 237 according to the present embodiment. As shown in FIG. 10, the stator core 237 has the same configuration as the stator core 37 according to the first embodiment except for the configuration of the ring 231.

[0064] As shown in FIG. 10, in the stator core 237, the cylindrical inner peripheral portion 231a of the ring 231 has a plurality of recesses 231ar that are recessed radially outward. The plurality of (six in this embodiment) recesses 231ar are formed at predetermined intervals (equal intervals in this embodiment) in the circumferential direction, and in this embodiment, they are formed at intervals of 60°. There is a protruding portion 236 inside each of the six recesses 231ar of the stator core 237. Inside the inner peripheral portion 231a is a through hole (hole portion) 231h that penetrates the stator core 237 in the axial direction. The upper portion of the above-described cylindrical portion 13 is disposed approximately in the lower half of this through hole 231h, and approximately the lower half portion of the inner peripheral portion 231a of the ring 231 is fixed to the outer peripheral surface 13e of the upper portion of the cylindrical portion 13. The shaft 20 passes through the inside of this through hole 231h.

[0065] The stator core 237 is formed by a plurality of magnetic bodies 290 stacked in the axial direction. Each of the plurality of magnetic bodies 290 includes a ring 291, a plurality of plate-like portions 92, and a magnetic pole portion 95 connected to the outer end of each of the plurality of plate-like portions 92. Teeth are formed by the plate-like portions 92 and the magnetic pole portions 95. Each of the plurality of magnetic bodies 290 includes an inner peripheral portion 291a that constitutes the inner peripheral portion 231a of the ring 231, and six recesses 291ar that form the six recesses 231ar of the ring 231. When viewed from the axial direction, the recesses 291ar are formed in a rectangular or square shape with the inner peripheral side open. Therefore, the recesses 231ar of the stator core 37 formed by stacking the recesses 291ar are formed in a rectangular parallelepiped shape with the upper and lower sides in the axial direction and the inner side in the radial direction open. In the stator core 237, there is a protruding portion 236 inside each of these recesses 231ar.

[0066] Also, focusing on each of the six protruding portions 236, as shown in FIG. 10, when viewed from the axial direction, the plate-like portion 32 and the magnetic pole portion 35 are arranged side by side on a straight line La that extends radially through the center C of the stator core 237 (the center C of the shaft 20) and the protruding portion 236. Further, each of the protruding portion 236, the concave portion 231ar, the plate-like portion 32, and the magnetic pole portion 35 has a shape that is generally line-symmetrical with respect to the straight line La. That is, in the present embodiment, in the circumferential direction, the portion of the inner peripheral portion 231a of the ring corresponding to the plate-like portion 32 (the portion of the inner peripheral portion 231a on the straight line La) has the concave portion 231ar, and the protruding portion 236 is inside this concave portion 231ar.

[0067] The six protruding portions 236 of the stator core 237 include three first protruding portions 238 and three second protruding portions 239. The three first protruding portions 238 are three protruding portions 236 arranged at intervals of 120°. The three second protruding portions 239 are three protruding portions 236 located at positions rotated 60° with respect to the three first protruding portions 238. In the axial direction, a magnetic body 290 having a protruding portion 296 that forms the first protruding portion 238 (hereinafter, may be referred to as the "first protruding portion 298") (hereinafter, may be referred to as the "first magnetic body 294") and a magnetic body 290 having a protruding portion 296 that forms the second protruding portion 239 (hereinafter, may be referred to as the "second protruding portion 299") (hereinafter, may be referred to as the "second magnetic body 297") are alternately stacked in the axial direction.

[0068] The first magnetic body 294 has three first protrusions 298. The three first protrusions 298 of each of the plurality of first magnetic bodies 294 are stacked with a gap approximately equal to the thickness of one magnetic body 290 in the axial direction, so that the three first protrusions 238 are formed inside each of the three recesses 231ar. Further, the second magnetic body 297 has three second protrusions 299. The three second protrusions 299 of each of the plurality of second magnetic bodies 297 are stacked with a gap approximately equal to the thickness of one magnetic body 290 in the axial direction, so that the three second protrusions 239 are formed inside each of the other three recesses 231ar. In the circumferential direction, the second protrusion 299 is at a position rotated 60° with respect to the first protrusion 298.

[0069] According to the stator core 237 in the present embodiment, since each of the plurality of protrusions 236 is inside the recess 231ar, the inner peripheral portion 231a of the stator core 237 can be fitted onto the outer peripheral surface 13e of the cylindrical portion 13 without being interfered by the protrusions 236. Therefore, according to the stator core 237 of the present embodiment, it is easy to attach the stator core 237 to the cylindrical portion 13 by press-fitting.

[0070] Since the stator core 237 in the present embodiment has a plurality of protrusions 2, the ring 231, the plate-like portion 32, and the magnetic pole portion 35 have flat and continuous surfaces. Thus, similar to the first embodiment, a path through which magnetic flux passes through the ring 231, the plate-like portion 32, and the magnetic pole portion 35 can be ensured. That is, according to the present embodiment, it is possible to enable the motor to exhibit good performance, and a motor including such a stator core 237 can exhibit good performance.

[0071] The stator core 237 can be manufactured by clamping the laminate 750 shown in FIG. 11. FIG. 11 is a perspective view showing the laminate 750.

[0072] As shown in FIG. 11, the laminate 750 is configured by axially stacking a plurality of magnetic plates 700, and has substantially the same configuration as the laminate 550 according to the first embodiment. That is, each of the plurality of magnetic plates 700 constituting the laminate 750 has substantially the same configuration as each of the plurality of magnetic plates 500 constituting the laminate 550. On the other hand, the magnetic plate 700 is different from the magnetic plate 500 constituting the laminate 550 in the following points. That is, a plurality of (six in this embodiment) recesses 291ar are formed in the inner peripheral portion 291a of the ring 291 of the magnetic plate 700. In the magnetic plate 700, spokes 711 extend radially inward from three of the six recesses 291ar. In the magnetic plate 700, the three spokes 711 are arranged at equal intervals in the circumferential direction (that is, at intervals of 120°). In the magnetic plate 700, the three spokes 711 are connected to an inner portion 512 having the same configuration as the inner portion 512 of the magnetic plate 500. The magnetic plate 700 has a central portion 710 including the inner portion 512 and the three spokes 711.

[0073] The laminate 750 is configured by rotating the upper magnetic plate (second magnetic plate 700B) 60° with respect to the lower magnetic plate 700 (first magnetic plate 700A) and stacking them. For this reason, as shown in FIG. 11, in a pair of adjacent first magnetic plates 700A, 700A in the axial direction among the plurality of first magnetic plates 700A, a gap corresponding to the thickness of one magnetic plate 700 is formed between the respective spokes 711A. Similarly, in a pair of adjacent second magnetic plates 700B, 700B in the axial direction, a gap corresponding to the thickness of one magnetic plate 700 is formed between the respective spokes 711B. On the other hand, in the axial direction, the inner portions 512 of the plurality of magnetic plates 700 are in contact with each other (substantially in surface contact) and stacked. In the laminate 750, the stacked spokes 711A may be collectively referred to as the "spoke 711A group", and the stacked spokes 711B may be collectively referred to as the "spoke 711B group".

[0074] In this embodiment, the inner portion 512 of each of the plurality of magnetic plates 700 constituting the laminate 750 is clamped in the same manner as in the first embodiment (clamping step). As a result, the plurality of magnetic plates 700 constituting the laminate 750 are integrated via the clamped portion 515 of the inner portion 512. The magnetic plate 700 has the same configuration as the magnetic body 290 except for having a central portion 710. Therefore, the laminate 750 formed by stacking the magnetic plates 700 also includes a ring 231, an inner peripheral portion 231a, a plurality of plate-like portions 32, and a plurality of magnetic pole portions 35. Further, in the laminate 750, the second magnetic plate 700B corresponds to the first magnetic body 294 described above, and the first magnetic plate 700A corresponds to the second magnetic body 297 described above.

[0075] After integrating the plurality of magnetic plates 500 of the laminate 750 by the clamping step, in the same manner as in the first embodiment, an insulator 34 (see FIG. 2) is attached to each of the plurality of plate-like portions 32 of the laminate 750, and further, a coil 33 (see FIG. 2) is wound around each of the attached plurality of insulators 34 (attachment step). Then, after the attachment step, the plurality of (three in this embodiment) spoke 711A groups and the plurality of (three in this embodiment) spoke 711B groups of the laminate 550 are cut by the same method as in the first embodiment (cutting step). However, in the cutting step in this embodiment, it should be noted that in each of the spoke 711A group and the spoke 711B group, the spoke 711A group and the spoke 711B group are cut at a location inside the recess 231ar.

[0076] In this way, a stator having the stator core 237 according to this embodiment is manufactured.

[0077] According to this manufacturing method, since the central portion 710 where the clamped portion 515 is formed is cut, a portion through which magnetic flux in the stator core, such as a ring, a plate-like portion, and a magnetic pole portion, can be continuously formed of a magnetic body, and the stator core can be manufactured.

[0078] Note that, in this embodiment, the shape of the concave portion 231ar (concave portion 291ar) is not limited to that described above. For example, a laminate 750A having a concave portion 231arA (concave portion 291arA) as shown in FIG. 12 may be configured. The concave portion 231arA (concave portion 291arA) widens as it goes inward in the radial direction and is formed in a trapezoid shape when viewed from the axial direction. In such a concave portion 231arA (concave portion 291arA), since the space inside the concave portion 231arA is flaring, it is easy to approach the mold Mo or the laser Lr to the cutting portions in the spoke 711A group and the spoke 711B group. Therefore, the spoke 711A group and the spoke 711B group can be cut more easily. And, in the stator core manufactured from such a laminate 750A according to such a modification example, the concave portion flares as it goes inward in the radial direction, and there is a protruding portion inside this concave portion.

[0079] As described above, the present invention has been described by taking the above embodiment and each modification example as examples, but the present invention is not limited thereto.

[0080] In the above-described embodiment, an example in which the first magnetic body and the second magnetic body are alternately stacked in the axial direction has been described. However, after stacking the first magnetic body over one layer or several layers in the axial direction, the second magnetic body may be stacked over several layers. Alternatively, after stacking the first magnetic body over several layers in the axial direction, the second magnetic body may be stacked over one layer or several layers.

[0081] In addition, those skilled in the art can appropriately modify the present invention according to conventionally known knowledge to other types of motors such as an inner rotor type brushless motor, a brushed motor, and a fan motor. As long as the configuration of the present invention is still provided by such a modification, of course, it is included in the scope of the present invention.

Explanation of Reference Numerals

[0082] 1… motor, 30… stator, 40… rotor, 90, 290… magnetic body, 91, 291… ring, 91a, 291a… inner peripheral part, 92… plate-like part, 94… first magnetic body, 95… magnetic pole part, 96… protruding part, 97… second magnetic body, 291ar, 291arA… recess, Gp1, Gp2… gap

Claims

1. Comprising a plurality of magnetic bodies having an inner peripheral portion and a plurality of protruding portions extending inward from the inner peripheral portion, The plurality of magnetic bodies include a first magnetic body and a second magnetic body that overlap in the axial direction, In the circumferential direction, the positions of the plurality of protruding portions of the first magnetic body are different from the positions of the plurality of protruding portions of the second magnetic body, a stator.

2. The plurality of magnetic bodies include a plurality of first magnetic bodies including the first magnetic body and a plurality of second magnetic bodies including the second magnetic body, In the axial direction, the plurality of first magnetic bodies including the first magnetic body and the plurality of second magnetic bodies including the second magnetic body are stacked, In the axial direction, the plurality of protruding portions of the plurality of first magnetic bodies face each other, In the axial direction, the plurality of protruding portions of the plurality of second magnetic bodies face each other, the stator according to claim 1.

3. The inner peripheral surface of the protruding portion is a cut surface, the stator according to claim 1 or 2.

4. In the axial direction, there is a gap between the plurality of protruding portions of the plurality of first magnetic bodies facing each other, In the axial direction, there is a gap between the plurality of protruding portions of the plurality of second magnetic bodies facing each other, the stator according to claim 2.

5. The magnetic body includes a ring having the inner peripheral portion, a plurality of magnetic pole portions, and a plurality of plate-like portions connecting the ring and the plurality of magnetic pole portions, In the circumferential direction, the width of the protruding portion is smaller than the width of the plate-like portion, The stator according to any one of claims 1 to 4.

6. In the circumferential direction, a portion of the inner peripheral portion of the ring corresponding to the plate-like portion has a recess, The protruding portion is inside the recess, the stator according to claim 5.

7. The stator according to any one of claims 1 to 6, And a rotor A motor comprising.

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