Manufacturing method of motor core and manufacturing method of stator

Abstract

A motor core manufacturing method for manufacturing a motor core of a radial gap motor having an annular back yoke and a plurality of teeth extending from the back yoke, the motor core manufacturing method comprising: a preparation step of preparing a plurality of split cores having an arcuate back yoke part and teeth extending from the back yoke part; an insertion step of inserting back yoke portions of the plurality of split cores into a back yoke mold forming an outer circumferential surface and an inner circumferential surface of the back yoke; and a pressing step of pressing the back yoke parts of the plurality of split cores in the back yoke mold after the insertion step.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a motor core and a method for manufacturing a stator. Background Technology

[0002] In radial clearance motors, a motor core (stator core) with multiple teeth extending from a ring-shaped back yoke is used. In this type of motor core, windings are wound around each tooth to generate a magnetic field.

[0003] Previous technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-168413 Summary of the Invention

[0006] The technical problem to be solved by the invention

[0007] In a motor core, multiple teeth are adjacent to each other, so a method called auger winding is used to wind the wire around each tooth. In auger winding, a wire is released from the front end of the auger and the auger is made to wrap around the teeth, thereby winding the wire around each tooth. However, in this type of auger winding, there are limitations to increasing the winding density, making it difficult to increase the magnetic flux density.

[0008] Therefore, a method for increasing magnetic flux density by manufacturing a motor core by joining multiple segmented cores is considered (for example, see Patent Document 1). Each segmented core consists of an arc-shaped back yoke and a tooth extending from the back yoke. In the segmented core, there are no obstructions around the tooth, allowing the winding to be wound densely around it. Therefore, after winding the winding around the teeth of each segmented core, joining multiple segmented cores results in high-density winding of the winding, thus achieving a high magnetic flux density.

[0009] When manufacturing a motor core in this way, one could consider joining adjacent segmented cores by welding or gluing after winding the wire onto the teeth of each segmented core and arranging them in a ring. However, if the multiple segmented cores are not aligned with extremely high precision, the roundness of the back yoke will be low. Therefore, after joining the multiple segmented cores, it is necessary to machine the inner and outer circumferential surfaces of the back yoke to improve its roundness.

[0010] Furthermore, sometimes the pressed powder molded body is used as a motor core. However, since it is difficult to cut the pressed powder molded body with high precision, if multiple segmented cores composed of pressed powder molded bodies are joined by the above method, it is difficult to cut the inner and outer circumferential surfaces of the back yoke to improve the roundness of the back yoke.

[0011] Therefore, the objective of this invention is to provide a method for manufacturing a motor core that can achieve high magnetic flux density and easily improve the roundness of the back yoke, and a method for manufacturing a stator.

[0012] means for solving technical problems

[0013] [1] The method for manufacturing a motor core involved in this invention is a method for manufacturing a radial clearance motor core having an annular back yoke and a plurality of teeth extending from the back yoke. The method for manufacturing a motor core includes: a preparation step, preparing a plurality of segmented cores, the plurality of segmented cores having an arc-shaped back yoke portion and teeth extending from the back yoke portion; an insertion step, inserting the back yoke portions of the plurality of segmented cores into a back yoke mold forming the outer peripheral surface and the inner peripheral surface of the back yoke; and a pressurizing step, after the insertion step, pressurizing the back yoke portions of the plurality of segmented cores in the back yoke mold.

[0014] In this method for manufacturing a motor core, a plurality of segmented cores, each having a yoke and teeth, are used. Therefore, in each of the segmented cores, the winding can be wound onto the teeth. This allows for high-density winding onto the teeth, resulting in high magnetic flux density. Furthermore, the yoke portions of the multiple segmented cores are inserted into a yoke mold, and pressure is applied within the mold. This causes the yoke portions to elongate in a direction different from the pressure direction and be pressed against the mold. By forming the yoke portions of the multiple segmented cores using the mold, the roundness of the yoke formed by the yoke portions of the multiple segmented cores can be easily improved. Additionally, after the pressure application process, by joining adjacent yoke portions or binding the multiple yoke portions with straps, a yoke with multiple segmented cores connected together can be obtained.

[0015] [2] In the method for manufacturing the motor core described in [1], the connecting end face of the back yoke connected to the adjacent segmented core can be formed as a plane. In this method for manufacturing the motor core, the connecting end face of the back yoke is formed as a plane, thus making it easy to manufacture the segmented core.

[0016] [3] In the manufacturing method of the motor core described in [1], the connecting end face of the back yoke connected to the adjacent segmented core can be bent into an arc shape. In this manufacturing method of the motor core, the connecting end face of the back yoke is bent into an arc shape, so that when the back yokes of multiple segmented cores are inserted into the back yoke mold, it is easy to align the multiple segmented cores.

[0017] [4] In the manufacturing method of the motor core described in [3], the connecting end face on one side of the back yoke can be bent into a convex shape, and the connecting end face on the other side of the back yoke can be bent into a concave shape. In this manufacturing method of the motor core, the connecting end face on one side of the back yoke is bent into a convex shape, and the connecting end face on the other side of the back yoke is bent into a concave shape, so that multiple segmented cores can be made to have the same shape, and the connecting end face of the back yoke can be bent into an arc shape.

[0018] [5] The method for manufacturing a motor core according to any one of [1] to [4] may further include: a connecting step, wherein after the pressing step, adjacent back yoke portions of a plurality of segmented cores are joined. In this method for manufacturing a motor core, after the pressing step, by joining adjacent back yoke portions of a plurality of segmented cores, a back yoke to which the back yoke portions of the plurality of segmented cores are connected can be obtained.

[0019] [6] The method for manufacturing the motor core in any one of [1] to [5] may further include:

[0020] In the connection process, after the pressurization process, multiple segmented cores are bound together with strapping tape. In this method of manufacturing a motor core, after the pressurization process, multiple segmented cores are bound together with strapping tape, thereby obtaining a back yoke with multiple segmented cores connected together.

[0021] [7] In any of the manufacturing methods of the motor core described in [1] to [6], the plurality of segmented cores may each be a powder-pressed molding body. In this manufacturing method of the motor core, since the plurality of segmented cores are powder-pressed molding bodies, it is difficult to perform high-precision cutting. However, as described above, by means of the insertion process and the pressing process, the roundness of the back yoke formed by the back yoke portion of the plurality of segmented cores can be easily improved.

[0022] [8] The stator manufacturing method of the present invention is a method for manufacturing a stator of a radial clearance motor having an annular back yoke, a plurality of teeth extending from the back yoke, and windings respectively wound on the plurality of teeth. The stator manufacturing method includes: a preparation step, preparing a plurality of segmented cores, the plurality of segmented cores having an arc-shaped back yoke portion and teeth extending from the back yoke portion; a winding step, winding the windings on each tooth of the plurality of segmented cores; an insertion step, after the winding step, inserting the back yoke portions of the plurality of segmented cores into a back yoke mold forming the outer and inner peripheral surfaces of the back yoke; and a pressing step, after the insertion step, pressing the back yoke portions of the plurality of segmented cores in the back yoke mold.

[0023] In this stator manufacturing method, a winding is wound onto the teeth of multiple segmented cores. This allows for high-density winding of the winding onto the teeth, resulting in a high magnetic flux density. Then, the back yoke portions of the multiple segmented cores are inserted into a back yoke mold, and pressure is applied within the mold. This causes the back yoke portions to elongate in a direction opposite to the pressure direction and be pressed into the mold. Thus, the back yoke portions of multiple segmented cores are formed using the back yoke mold, making it easier to improve the roundness of the back yoke composed of these portions. Furthermore, after the pressure application process, by joining adjacent back yoke portions or binding the multiple back yoke portions with straps, a back yoke with multiple segmented cores connected together can be obtained.

[0024] [9] In the stator manufacturing method described in [8], after the pressing step, a connecting step may be included, in which adjacent back yoke portions of a plurality of segmented cores are joined after the pressing step. In this stator manufacturing method, after the pressing step, by joining adjacent back yoke portions of a plurality of segmented cores, a back yoke with multiple segmented cores connected together can be obtained.

[0025]

[10] In the stator manufacturing method described in [8] or [9], each of the multiple segmented cores can be a powder-pressed body. In this stator manufacturing method, since each of the multiple segmented cores is a powder-pressed body, it is difficult to perform high-precision cutting. However, as described above, by means of the insertion process and the pressing process, the roundness of the back yoke formed by the back yoke of the multiple segmented cores can be easily improved.

[0026] Invention Effects

[0027] It can achieve high magnetic flux density and easily improve the roundness of the back yoke. Attached Figure Description

[0028] Figure 1 This is a schematic cross-sectional view of the radial clearance motor involved in the embodiment.

[0029] Figure 2 This is a perspective view of the motor core involved in this embodiment.

[0030] Figure 3 This is a three-dimensional view of the segmented core prepared during the preparation process.

[0031] Figure 4 yes Figure 3 The cross-sectional view of the teeth shown.

[0032] Figure 5 This is a front view used to illustrate the winding process.

[0033] Figure 6 This is the main view used to illustrate the insertion process.

[0034] Figure 7 It is a cross-sectional view used to illustrate the pressurization process.

[0035] Figure 8 It is a cross-sectional view used to illustrate the pressurization process.

[0036] Figure 9 It is a cross-sectional view used to illustrate the pressurization process.

[0037] Figure 10 It is a sectional view used to illustrate the connection process.

[0038] Figure 11 This is a top view of multiple segmented cores in a modified example.

[0039] Figure 12 This is a cross-sectional view of the tooth in a modified example.

[0040] Figure 13 This is a top view of the motor core in a modified example. Detailed Implementation

[0041] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Furthermore, in the drawings, the same or corresponding parts are labeled with the same symbols, and repeated descriptions are omitted. Also, in the drawings, the dimensions and proportions have been appropriately changed for ease of understanding.

[0042] [Radial clearance motor]

[0043] Figure 1 This is a schematic cross-sectional view of the radial clearance motor according to the embodiment. Figure 1 As shown, the radial clearance motor 1 according to this embodiment includes: a stator 2; a rotor 3 configured to rotate relative to the stator 2; and a shaft 4 fixed to the rotor 3. The stator 2 and the rotor 3 are separated in the radial direction of the shaft 4. A shaft hole 5 for inserting the shaft 4 is formed in the center of the rotor 3.

[0044] [stator]

[0045] The stator 2 involved in this embodiment is the stator of a radial clearance motor 1. The stator 2 includes a motor core 6 and a winding 7 wound on the motor core 6. The motor core 6 is the portion of the stator 2 with the winding 7 removed, and is also referred to as the stator core.

[0046] [Motor Core]

[0047] Figure 2 This is a perspective view of the motor core involved in this embodiment. Figure 1 and Figure 2As shown, the motor core 6 according to this embodiment has an annular back yoke 8 and a plurality of teeth 9 extending from the back yoke 8. Here, the axial direction of the back yoke 8 is referred to as the axial direction D1, the radial direction of the back yoke 8 is referred to as the radial direction D2, and the circumferential direction of the back yoke 8 is referred to as the circumferential direction D3. The axial direction D1 is also the thickness direction of the back yoke 8 (the direction of the rotation axis of the rotor 3 in the radial clearance motor 1). The radial direction D2 is also the radial direction of the annulus formed by the back yoke 8 (the radial direction of the rotor 3 in the radial clearance motor 1). The circumferential direction D3 is also the circumferential direction of the annulus formed by the back yoke 8 (the rotation direction of the rotor 3 in the radial clearance motor 1).

[0048] Multiple teeth 9 extend from the back yoke 8 in the radial direction D2 inward. In this embodiment, the case where the motor core 6 has 4 teeth 9 will be described, but the number of teeth 9 is not particularly limited as long as there are 2 or more.

[0049] The outer peripheral surface 8a of the back yoke 8 is formed into a perfect circle. Furthermore, the perfect circle shape includes not only a complete perfect circle but also a shape that is approximately a perfect circle due to manufacturing errors, etc. The inner peripheral surface 8b of the back yoke 8 can be formed into an arc shape, a planar shape, or a polygonal shape.

[0050] [Manufacturing method of motor core and stator]

[0051] Next, the manufacturing method of the motor core and stator according to this embodiment will be described. This manufacturing method is the method for manufacturing the motor core 6 and stator 2 described above.

[0052] The manufacturing methods for motor cores and stators include preparation, winding, insertion, pressing, and connection processes.

[0053] Figure 3 This is a three-dimensional view of the segmented core prepared during the preparation process. Figure 4 yes Figure 3 The cross-sectional view of the teeth shown. (As shown) Figure 3 and Figure 4 As shown, in the preparation process, multiple segmented cores 10 are prepared. These multiple segmented cores 10 are, for example, identical in shape to each other. Each of the multiple segmented cores 10 has an arc-shaped back yoke portion 11 and teeth 9 extending from the back yoke portion 11. Here, the direction in which the back yoke portion 11 extends in an arc shape is called the arc direction D4, the radial direction of the arc formed by the back yoke portion 11 is called the radial direction D5, and the direction orthogonal to the arc direction D4 and the radial direction D5 is called the thickness direction D6. The arc direction D4 is also the circumferential direction D3 of the motor core 6. The radial direction D5 is also the radial direction D2 of the motor core 6. The thickness direction D6 is also the axial direction D1 of the motor core 6.

[0054] The back yoke portion 11 is formed by dividing the back yoke 8 along the circumferential direction D3. Furthermore, the back yoke portions 11 of multiple segmented cores 10 are connected in a ring configuration to form the back yoke 8 of the motor core 6. The two end faces of the back yoke portion 11 in the arc direction D4 become connecting end faces that connect with the back yoke portions 11 of adjacent segmented cores 10. The connecting end face on one side of the back yoke portion 11 is referred to as the first connecting end face 13, and the connecting end face on the other side of the back yoke portion 11 is referred to as the second connecting end face 14. The first connecting end face 13 and the second connecting end face 14 are formed as planes along the radial direction D5 and the thickness direction D6.

[0055] The tooth 9 is one of the multiple teeth 9 of the motor core 6. That is, one tooth 9 is provided on one segmented core 10. The tooth 9 has a winding surface 15 for the winding wire 7 to be wound. The winding surface 15 is the surface of the tooth 9 surrounding the radial direction D5. The winding surface 15 has a first winding face 15a and a second winding face 15b opposite to the thickness direction D6, and a third winding face 15c and a fourth winding face 15d opposite to the arc direction D4. The first winding face 15a and the second winding face 15b are adjacent to the third winding face 15c on one side in the arc direction D4, and the first winding face 15a and the second winding face 15b are adjacent to the fourth winding face 15d on the other side in the arc direction D4. Furthermore, one side of the third winding face 15c and the fourth winding face 15d in the thickness direction D6 is adjacent to the first winding face 15a, and the other side of the third winding face 15c and the fourth winding face 15d in the thickness direction D6 is adjacent to the second winding face 15b. Moreover, the winding surface 15 of the tooth 9 is formed into a rectangle by the first winding face 15a, the second winding face 15b, the third winding face 15c, and the fourth winding face 15d.

[0056] Multiple segmented cores 10 are, for example, compacted bodies formed by pressing soft magnetic powder covered with insulating material. The multiple segmented cores 10, as compacted bodies, can be formed individually using commercially available compaction equipment. The raw materials for the soft magnetic powder are, for example, pure iron, iron-silicon, or iron-cobalt. The average particle size of the soft magnetic powder is, for example, 3 μm or more and 300 μm or less, 30 μm or more and 200 μm or less, or 50 μm or more and 150 μm or less. The raw materials for the insulating material are, for example, insulating films containing phosphate, silicone, etc. Furthermore, the average particle size of the soft magnetic powder is measured using a robotic sieve (model: RPS-205) manufactured by Seishin Enterprise Co., Ltd. Additionally, the multiple segmented cores 10 can each be a laminate formed by stacking multiple electromagnetic steel sheets.

[0057] The winding process can be performed at any time as long as it precedes the insertion process. For example, the winding process can be performed before, after, or simultaneously with the preparation process. Figure 5 This is a front view used to illustrate the winding process. For example... Figure 5 As shown, in the winding process, the winding wire 7 is wound onto each tooth 9 of the plurality of dividing cores 10. Regarding winding the winding wire 7 onto the tooth 9, for example, it can be done by rotating the dividing cores 10 to wind the winding wire 7 onto the winding surface 15 of the tooth 9, such as spindle winding, wire nozzle winding, or fly fork winding.

[0058] The insertion process is performed after the preparation and winding processes. Figure 6 This is the main view used to illustrate the insertion process. For example... Figure 6 As shown, in the insertion process, the back yoke portions 11 of multiple segmented cores 10 are inserted into the back yoke mold 20. The back yoke mold 20 is the back yoke 8 that forms the motor core 6 (see reference). Figure 2 The forming mold for the outer peripheral surface 8a and the inner peripheral surface 8b of the yoke 8. The back yoke mold 20 has an outer mold portion 21 that forms the outer peripheral surface 8a of the back yoke 8 and an inner mold portion 22 that forms the inner peripheral surface 8b of the back yoke 8.

[0059] The outer mold portion 21 has an outer mold forming surface 21a for forming the outer peripheral surface 8a of the back yoke 8. The outer mold forming surface 21a is formed into a perfect circle shape corresponding to the outer peripheral surface 8a of the back yoke 8.

[0060] The inner mold portion 22 has a plurality of inner mold forming surfaces 22a for forming the inner peripheral surface 8b of the back yoke 8. The plurality of inner mold forming surfaces 22a are each formed in a shape corresponding to the portion between adjacent teeth 9 of the inner peripheral surface 8b of the back yoke 8.

[0061] The outer mold portion 21 and the inner mold portion 22 can be one mold or another mold. When the outer mold portion 21 and the inner mold portion 22 are different molds, the outer mold portion 21 can, for example, be formed as an annular shape with the outer mold forming surface 21a as its inner circumferential surface. Furthermore, when the outer mold portion 21 and the inner mold portion 22 are different molds, the inner mold portion 22 can, for example, be a mold having multiple inner mold forming surfaces 22a, or it can be a mold having multiple arc-shaped inner mold forming surfaces 22a, each with multiple arc-shaped features.

[0062] Furthermore, multiple segmented cores 10 are inserted into the back yoke mold 20 so that the teeth 9 of the multiple segmented cores 10 are arranged between the multiple inner mold forming surfaces 22a. Thus, the back yoke portions 11 of the multiple segmented cores 10 are arranged in a ring shape, similar to the back yoke 8 of the motor core 6. In addition, during the winding process performed before the insertion process, the winding wire 7 is wound on the teeth 9, so the back yoke mold 20 (inner mold portion 22) is formed so that it does not interfere with the winding wire 7 wound on the teeth 9 during the winding process.

[0063] The pressurization process is performed after the insertion process. Figures 7-9 This is a cross-sectional view used to illustrate the pressurization process. Additionally, Figure 7 and Figure 8 yes Figure 6 The sectional view shown is taken along line VII-VII. Figure 9 yes Figure 8 The sectional view shown is taken along line IX-IX. Figures 7-9 As shown, in the pressing process, the back yoke portions 11 of the multiple segmented cores 10 are pressed within the back yoke mold 20. That is, the back yoke portions 11 of the multiple segmented cores 10 are pressed along the thickness direction D6. The thickness direction D6 is both the direction of the central axis of the back yoke portions 11 of the multiple segmented cores 10 arranged in a ring and the axial direction D1 of the motor core 6. In this way, the back yoke portions 11 of the multiple segmented cores 10 inserted into the back yoke mold 20 shrink in the pressing direction and elongate in a direction different from the pressing direction. Moreover, the back yoke portions 11 of the multiple segmented cores 10 are pressed along the thickness direction D6 until the back yoke portions 11 of the multiple segmented cores 10 are elongated and pressed against the outer mold portion 21 (outer mold forming surface 21a) and the inner mold portion 22 (inner mold forming surface 22a) of the back yoke mold 20. Therefore, the back yoke portions 11 of the multiple segmented cores 10 are formed by the outer mold portion 21 (outer mold forming surface 21a) and the inner mold portion 22 (inner mold forming surface 22a) of the back yoke mold 20. Thus, even if the back yoke portions 11 of the multiple segmented cores 10 are not precisely aligned, by applying pressure to the back yoke portions 11 of the multiple segmented cores 10 within the back yoke mold 20 and pressing the back yoke portions 11 of the multiple segmented cores 10 against the back yoke mold 20, the back yoke portions 11 of the multiple segmented cores 10 are in a state of high-precision alignment.

[0064] Furthermore, when each of the multiple segmented cores 10 is a powder-pressed body, the powder-pressed body is repressed during the pressing process. Moreover, when each of the multiple segmented cores 10 is a powder-pressed body, compared to the case where the multiple segmented cores 10 are a laminated body made of multiple layers of electromagnetic steel plates, the elongation of the multiple segmented cores 10 in a direction different from the repressing direction of the back-to-back yoke 11 is more likely to increase when repressed.

[0065] The connection process is performed after the pressurization process. Figure 10 This is a sectional view used to illustrate the connection process. For example... Figure 10 As shown, in the connecting process, the back yoke portions 11 of multiple segmented cores 10 are connected. The connecting process is performed, for example, with the back yoke portions 11 of the multiple segmented cores 10 inserted into the back yoke mold 20. The connection of the back yoke portions 11 of the multiple segmented cores 10 is performed by joining adjacent back yoke portions 11 of the multiple segmented cores 10. That is, the first connecting end face 13 of an adjacent back yoke portion 11 and the second connecting end face 14 of another adjacent back yoke portion 11 are joined. The joining of adjacent back yoke portions 11 of the multiple segmented cores 10 can be performed by welding, gluing, or the like. Afterwards, the back yoke portions 11 of the multiple segmented cores 10 are removed from the back yoke mold 20.

[0066] Thus, the motor core 6 and stator 2 are obtained. That is, the back yoke portions 11 of the multiple segmented cores 10 are interconnected to form an annular back yoke 8, and the teeth 9 of the multiple segmented cores 10 become multiple teeth 9 extending from the back yoke 8. In addition, by not performing the above-mentioned winding process, it is possible to manufacture a motor core 6 without the winding 7.

[0067] As explained above, in the method for manufacturing a motor core according to this embodiment, a plurality of segmented cores 10 having a back yoke portion 11 and teeth 9 are used to manufacture the motor core 6. Therefore, in each of the plurality of segmented cores 10, the winding 7 can be wound onto the teeth 9. As a result, the winding 7 can be wound onto the teeth 9 with high density, thus obtaining a high magnetic flux density. Furthermore, the back yoke portions 11 of the plurality of segmented cores 10 are inserted into a back yoke mold 20, and pressure is applied to the back yoke portions 11 of the plurality of segmented cores 10 within the back yoke mold 20. As a result, the back yoke portions 11 of the plurality of segmented cores 10 inserted into the back yoke mold 20 are extended in a direction different from the pressure direction and pressed into the back yoke mold 20. As a result, the back yoke portions 11 of the plurality of segmented cores 10 are formed by the back yoke mold 20, thus making it easy to improve the roundness of the back yoke 8 formed by the back yoke portions 11 of the plurality of segmented cores 10.

[0068] In the stator manufacturing method according to this embodiment, the winding 7 is wound onto each tooth 9 of the plurality of segmented cores 10. This allows the winding 7 to be wound onto the teeth 9 with high density, thus achieving a high magnetic flux density. Then, the back yoke portions 11 of the plurality of segmented cores 10 are inserted into a back yoke mold 20, and pressure is applied to the back yoke portions 11 within the back yoke mold 20. This causes the back yoke portions 11 of the plurality of segmented cores 10 inserted into the back yoke mold 20 to elongate in a direction different from the pressure direction and be pressed into the back yoke mold 20. Thus, the back yoke portions 11 of the plurality of segmented cores 10 are formed by the back yoke mold 20, thereby easily improving the roundness of the back yoke 8 formed by the back yoke portions 11 of the plurality of segmented cores 10.

[0069] Furthermore, in the manufacturing methods of the motor core and the stator, the first connecting end face 13 and the second connecting end face 14 of the back yoke 11 are formed as planes, thus making it easy to manufacture the segmented core 10.

[0070] Furthermore, in the manufacturing methods of the motor core and the stator, after the pressing process, by joining adjacent back yoke portions 11 of the multiple segmented cores 10, a back yoke 8 connected with the back yoke portions 11 of the multiple segmented cores 10 can be obtained.

[0071] Furthermore, in the manufacturing methods of the motor core and the stator, the multiple segmented cores 10 are each formed by pressing powder, making it difficult to cut them with high precision. However, as described above, by including the insertion process and the pressing process, the roundness of the back yoke 8, which is composed of the back yoke portions 11 of the multiple segmented cores 10, can be easily improved.

[0072] This invention is not limited to the above-described embodiments; appropriate modifications can be made without departing from the spirit of the invention.

[0073] For example, in the above embodiment, the case where the connecting end face of the back yoke, which connects to the adjacent segmented core, is formed as a plane has been described, but as... Figure 11 As shown, the connecting end face of the back yoke connected to the adjacent segmented core can be bent into an arc shape.

[0074] Figure 11 This is a top view of multiple segmented cores in a modified example. For example... Figure 11 As shown, in the modified example, the first connecting end face 13A and the second connecting end face 14A of the back yoke portion 11A of each of the plurality of segmented cores 10A are bent into an arc shape. The first connecting end face 13A is the connecting end face on one side of the back yoke portion 11A, and is bent into a convex shape, for example. The second connecting end face 14A is the connecting end face on the other side of the back yoke portion 11A, and is bent into a concave shape, for example.

[0075] Thus, by bending the first connecting end face 13A and the second connecting end face 14A of the back yoke portion 11A into an arc shape, it is easy to align the positions of the multiple segmented cores 10A during the stage of inserting the back yoke portion 11A of the multiple segmented cores 10A into the back yoke mold 20.

[0076] Furthermore, the first connecting end face 13A on one side of the back yoke 11A is bent into a convex shape, and the second connecting end face 14A on the other side of the back yoke 11A is bent into a concave shape, thereby enabling multiple segmented cores 10A to be set to the same shape, and bending the first connecting end face 13A and the second connecting end face 14A of the back yoke 11A into an arc shape.

[0077] Furthermore, in the above embodiment, the case where the winding surface of the gear is formed into a rectangle by the first winding surface, the second winding surface, the third winding surface, and the fourth winding surface has been described, but as... Figure 12 As shown, at least one corner of the winding surface of the gear can be formed into a curved surface.

[0078] Figure 12 This is a cross-sectional view of the tooth in a modified example. Figure 12The tooth 9B of the modified example shown has a winding surface 15B with a first winding surface 15Ba and a second winding surface 15Bb opposite to the thickness direction D6, and a third winding surface 15Bc and a fourth winding surface 15Bd opposite to the arc direction D4. The first winding surface 15Ba and the second winding surface 15Bb are adjacent to the third winding surface 15Bc on one side of the arc direction D4, and the first winding surface 15Ba and the second winding surface 15Bb are adjacent to the fourth winding surface 15Bd on the other side of the arc direction D4. Furthermore, the third winding surface 15Bc and the fourth winding surface 15Bd are adjacent to the first winding surface 15Ba on one side of the thickness direction D6, and the third winding surface 15Bc and the fourth winding surface 15Bd are adjacent to the second winding surface 15Bb on the other side of the thickness direction D6.

[0079] Furthermore, at least one of the following connections—the first wound face 15Ba and the third wound face 15Bc, the first wound face 15Ba and the fourth wound face 15Bd, the second wound face 15Bb and the third wound face 15Bc, and the second wound face 15Bb and the fourth wound face 15Bd—is connected in a curved shape. In this modified example, the first wound face 15Ba and the third wound face 15Bc, the first wound face 15Ba and the fourth wound face 15Bd, the second wound face 15Bb and the third wound face 15Bc, and the second wound face 15Bb and the fourth wound face 15Bd are all connected in a curved shape.

[0080] Thus, on the winding surfaces 15B of each tooth of the plurality of segmented cores, at least one of the following connections—the first winding surface 15Ba and the third winding surface 15Bc, the first winding surface 15Ba and the fourth winding surface 15Bd, the second winding surface 15Bb and the third winding surface 15Bc, and the second winding surface 15Bb and the fourth winding surface 15Bd—is connected in a curved shape. This makes it easier to wind the wire 7 along the winding surface 15B when it is wound around the tooth. Consequently, it is possible to prevent the wire 7 from floating off the winding surface 15B, thereby increasing the magnetic flux density.

[0081] Furthermore, in the above embodiment, the connection process was described as involving adjacent back yokes that join multiple segmented cores, but as... Figure 13 As shown, multiple segmented cores can also be connected by binding multiple segmented cores with straps, or by joining adjacent back yokes of multiple segmented cores and binding multiple segmented cores with straps.

[0082] Figure 13 This is a top view of a modified motor core. Figure 13In the illustrated motor core 6C, multiple segmented cores 10 are connected by being constrained by a strapping 30. The strapping 30 can be made of resin or metal, for example. In the manufacturing method of the motor core 6C and the manufacturing method of the stator having the motor core 6C, in the connection step, the multiple segmented cores 10 are constrained by the strapping 30, and the back yoke portions 11 of the multiple segmented cores 10 are connected.

[0083] Thus, after the pressurization process, multiple segmented cores 10 are constrained with strapping 30, thereby obtaining a back yoke 8 formed by connecting the back yoke portions 11 of multiple segmented cores 10.

[0084] Industrial availability

[0085] This invention can be used as a method for manufacturing motor cores and stators.

[0086] Symbol Explanation

[0087] 1-Radial clearance motor, 2-Stator, 3-Rotor, 4-Shaft, 5-Shaft hole, 6-Motor core, 7-Winding wire, 8-Back yoke, 8a-Outer circumferential surface, 8b-Inner circumferential surface, 9, 9B-Gears, 10, 10A-Divided core, 11, 11A-Back yoke portion, 13, 13A-First connecting end face, 14, 14A-Second connecting end face, 15, 15B-Winding surface, 15a, 15Ba-First winding surface portion 15b, 15Bb - Second winding face, 15c, 15Bc - Third winding face, 15d, 15Bd - Fourth winding face, 20 - Back yoke mold, 21 - Outer mold part, 21a - Outer mold forming surface, 22 - Inner mold part, 22a - Inner mold forming surface, 30 - Strapping strap, D1 - Axial direction, D2 - Radial direction, D3 - Circumferential direction, D4 - Arc direction, D5 - Radial direction, D6 - Thickness direction.

Claims

1. A method for manufacturing a motor core, comprising manufacturing a motor core of a radially spaced motor having an annular back yoke and a plurality of teeth extending from said back yoke. The manufacturing method of the motor core includes: The preparation process involves preparing multiple dividing cores, each dividing core having an arc-shaped back yoke portion and teeth extending from the back yoke portion. In the insertion process, the back yoke portion of the plurality of segmented cores is inserted into the back yoke mold that forms the outer and inner peripheral surfaces of the back yoke; and The pressurization process involves applying pressure to the back yoke portion of the plurality of segmented cores within the back yoke mold after the insertion process.

2. The method for manufacturing a motor core according to claim 1, wherein, The connecting end face of the back yoke, which is connected to the adjacent segmented core, is formed into a planar shape.

3. The method for manufacturing a motor core according to claim 1, wherein, The connecting end face of the back yoke, which is connected to the adjacent segmented core, is bent into an arc shape.

4. The method for manufacturing a motor core according to claim 3, wherein, The connecting end face on one side of the back yoke is bent into a convex shape. The connecting end face on the other side of the back yoke is bent into a concave shape.

5. The method for manufacturing a motor core according to any one of claims 1 to 4, further comprising: The joining process involves joining adjacent back yokes of the plurality of segmented cores after the pressurization process.

6. The method for manufacturing a motor core according to any one of claims 1 to 5, further comprising: In the connection process, after the pressurization process, the plurality of segmented cores are constrained with strapping.

7. The method for manufacturing a motor core according to any one of claims 1 to 6, wherein, The multiple segmented cores are each powder-pressed forming bodies.

8. A method for manufacturing a stator, comprising manufacturing a stator of a radially spaced motor having an annular back yoke, a plurality of teeth extending from the back yoke, and windings respectively wound around the plurality of teeth. The method for manufacturing the stator includes: The preparation process involves preparing multiple dividing cores, each dividing core having an arc-shaped back yoke portion and teeth extending from the back yoke portion. The winding process involves winding the wire onto each of the teeth of the plurality of segmented cores; In the insertion process, after the winding process, the back yoke portion of the plurality of segmented cores is inserted into the back yoke mold that forms the outer and inner peripheral surfaces of the back yoke. and The pressurization process involves applying pressure to the back yoke portion of the plurality of segmented cores within the back yoke mold after the insertion process.

9. The method for manufacturing a stator according to claim 8, further comprising: The joining process involves joining adjacent back yokes of the plurality of segmented cores after the pressurization process.

10. The method for manufacturing a stator according to claim 8 or 9, wherein, The multiple segmented cores are each powder-pressed forming bodies.

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