Motor

Abstract

To provide a motor in which an excessive load applied to a coil is suppressed.SOLUTION: The motor includes a stator (20) having a core part (42) around which a coil (22) is wound. The core part (42) has first surfaces (44, 45, 64) oriented in the direction of a rotation axis of the motor, and second surfaces (46, 47, 66, 67) oriented in a circumferential direction of the motor and continuous with the first surfaces (44, 45, 64). At a boundary between the first surfaces (44, 45, 64) and the second surfaces (46, 47, 66, 67), R parts (49, 71, 72) are formed which bulge toward the coil (22) side and come into contact with the coil (22).SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] In recent years, efforts to realize a low-carbon or carbon-free society have become more active, and research and development into motors as an electrification technology is being conducted in order to reduce CO2 emissions and improve energy efficiency in vehicles. Patent Document 1 describes a technology related to a motor stator formed by stacking electromagnetic steel sheets. Patent Document 1 discloses a technology for maintaining the stacked state of the electromagnetic steel sheets by providing a member that bundles the electromagnetic steel sheets in the stacking direction. Specifically, Patent Document 1 discloses a steel sheet fastening member that has pressure sections disposed on both axial sides of the back yoke section of the stator, and a connecting section that connects the pressure sections together via at least one of the outer and inner sides of the back yoke section. Patent Document 2 describes a technology in which a resin insulator is interposed between the stator and coil of a motor. That is, Patent Document 2 discloses a technology in which the core of the stator around which the coil is wound is formed by the teeth of the stator and the insulator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-55556 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-172478 Summary of the Invention [Problem to be solved by the invention]

[0004] In motor technology, a coil is wound around the core of the stator, but a problem arises in that the corners of the core come into contact with the coil, causing the coil to receive a localized excessive load from the corners. The present invention has been made in view of the above circumstances, and has an object to provide a motor in which the application of an excessive load to the coil is suppressed, thereby contributing to improvement of energy efficiency. [Means for solving the problem]

[0005] The motor is characterized in that it has a stator having a core portion around which a coil is wound, the core portion having a first surface that is oriented in the direction of the rotation axis of the motor, and a second surface that is continuous with the first surface and oriented in the circumferential direction of the motor, and an R portion that bulges toward the coil and contacts the coil is formed at the boundary between the first surface and the second surface. [Effects of the Invention]

[0006] This makes it possible to provide a motor in which excessive load is prevented from being applied to the coil, which in turn contributes to improving energy efficiency. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing an electric motor according to a first embodiment of the present invention; [Figure 2] FIG. 2 is a view showing a stator segment as viewed in the axial direction. [Figure 3] FIG. 2 is a perspective view of a stator segment. [Figure 4] FIG. [Figure 5] FIG. 3 is a cross-sectional view taken along line VV in FIG. 2. [Figure 6] FIG. 2 is an exploded perspective view of a stator core portion. [Figure 7] 10A and 10B are diagrams illustrating an example of a method for assembling stator segments. [Figure 8] FIG. 6 is a cross-sectional view of a stator segment according to a second embodiment of the present invention. [Figure 9] FIG. 10 is a cross-sectional view of a stator segment according to a third embodiment of the present invention. [Figure 10]FIG. 10 is a cross-sectional view of a stator segment according to a fourth embodiment of the present invention. [Figure 11] FIG. 10 is a cross-sectional view of a stator segment according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] [First embodiment] FIG. 1 is a diagram showing an electric motor 1 according to a first embodiment of the present invention. The electric motor (motor) 1 includes a casing 10, a stator 20 housed in the casing 10, and a rotor 30 rotatably supported by the casing 10.

[0010] The stator 20 has a substantially cylindrical stator core 21. Coils 22 are wound around the stator core 21 at predetermined angular intervals in the circumferential direction. In this embodiment, the stator core 21 has a structure divided in the circumferential direction. The stator core 21 is formed by stator segments 23, each having a coil 22, connected in the circumferential direction.

[0011] The rotor 30 is disposed radially inside the stator 20. The rotor 30 has a cylindrical rotor core 31. The rotor core 31 is formed by laminating electromagnetic steel sheets. Magnets (not shown) are disposed in the rotor core 31 at predetermined angular intervals in the circumferential direction. A motor shaft (rotating shaft) 32 is fixed to the radial center of the rotor core 31. The motor shaft 32 is fixed to the rotor core 31 while passing through the rotor core 31. When electric power is supplied to the electric motor 1, a magnetic field is generated by the coils 22 of the stator 20, the rotor 30 receives a force from the magnetic field and rotates, causing the motor shaft 32 to rotate.

[0012] Fig. 2 is a diagram showing the stator segment 23 as viewed in the axial direction. Fig. 3 is a perspective view of the stator segment 23. Fig. 4 is a perspective view of the stator core portion 40. Fig. 4 shows the stator segment 23 of Fig. 3 with the coils 22 omitted. In the description of this embodiment, when simply referring to the axial direction, it means the axial direction of the motor shaft 32. Therefore, an axial view means viewing in the axial direction of the motor shaft 32. Furthermore, when simply referring to the radial direction, it means the radial direction of the motor shaft 32. Furthermore, when simply referring to the circumferential direction, it means the circumferential direction of the motor shaft 32. One axial side, the other axial side, one circumferential side, the other circumferential side, the radial outer side, and the radial inner side are respectively indicated in the drawings by arrows A1, A2, C1, C2, R1, and R2.

[0013] The stator segment 23 has a stator core portion 40 around which the coil 22 is wound. The stator core portion 40 is formed in a substantially T-shape when viewed in the axial direction. The stator core portion 40 has a back yoke portion 41 extending in the circumferential direction. Teeth portions (core portions) 42 (see FIG. 4) extending in the radial direction are formed in the circumferential center of the back yoke portion 41. Widened portions 43 that are formed to be wider in the circumferential direction than the teeth portions 42 are formed at the radial inner ends of the teeth portions 42. The coil 22 is wound around the teeth portions 42 between the widened portions 43 and the back yoke portion 41.

[0014] A fixing hole 41a is formed in the circumferential center of the back yoke portion 41, penetrating in the axial direction. A convex portion 41b that protrudes in the circumferential direction is formed at the other circumferential end of the back yoke portion 41. Furthermore, a concave portion 41c (see FIG. 2) that is recessed in the circumferential direction is formed at one circumferential end of the back yoke portion 41. When viewed in the axial direction, the convex portion 41b of another stator core portion 40 is fitted into the concave portion 41c, connecting the stator segments 23 in the circumferential direction. By repeating this process, an annular stator 20 (see FIG. 1) is formed.

[0015] Fig. 5 is a cross-sectional view taken along line VV in Fig. 2. Fig. 5 corresponds to a view showing the stator segment 23 as viewed in the radial direction. The tooth portions 42 are generally prismatic. That is, the tooth portions 42 have planar axial faces (first faces) 44, 45 formed on both axial sides. The tooth portions 42 also have planar circumferential faces (second faces) 46, 47 formed on both circumferential sides. The axial faces 44, 45 are faces oriented in the axial direction. The circumferential faces 46, 47 are faces oriented in the circumferential direction. When viewed in the radial direction, the length of the axial faces 44, 45 is shorter than the length of the circumferential faces 46, 47. Therefore, the length of the axial faces 44, 45 in the winding direction of the coil 22 is shorter than that of the circumferential faces 46, 47.

[0016] At the boundary between the axial surfaces 44, 45 and the circumferential surfaces 46, 47, there is formed a rounded portion 49 that bulges toward the coil 22 and contacts the coil 22. The rounded portion 49 is formed so that the axial surfaces 44, 45 and the circumferential surfaces 46, 47 are not directly continuous with each other. That is, the rounded portion 49 is formed at a position where the axial surfaces 44, 45 and the circumferential surfaces 46, 47 do not form corners. In this embodiment, the rounded portion 49 is formed at both circumferential ends of the axial surfaces 44, 45. The rounded portion 49 has a predetermined radius of curvature. The predetermined radius of curvature is a radius large enough to allow the coil 22 to come into contact with the circumferential surfaces 46, 47 when the coil 22 is wound around the tooth portion 42 without applying a large local force to the coil 22. The predetermined radius of curvature is set based on experiments, etc. In this embodiment, the rounded portion 49 has a semicircular cross section. When viewed in the radial direction, the rounded portion 49 is formed in a semicircular shape that smoothly curves from the circumferential surfaces 46, 47. In other words, the rounded portion 49 is connected flush with the circumferential surfaces 46, 47 when viewed in the radial direction.

[0017] FIG. 6 is an exploded perspective view of the stator core portion 40. As shown in FIG. In the present embodiment, the R portion 49 is formed by an R portion-forming member (intervening member) 60. That is, the stator core portion 40 has a block-shaped main stator core portion 50 located on the side of the winding axis O22 (see FIG. 5 ) of the coil 22, and the R portion-forming member 60 in the form of a bent plate intervening between the main stator core portion 50 and the coil 22.

[0018] The main stator core portion 50 is formed in a block shape by laminating electromagnetic steel sheets punched to the same shape. The main stator core portion 50 has approximately the same external shape as the stator core portion 40. That is, the main stator core portion 50 has a back yoke portion 51, a main teeth portion (main core portion) 52, and an expanded portion 53 that constitute the back yoke portion 41, the teeth portion 42, and the expanded portion 43 of the stator core portion 40.

[0019] Here, as shown in FIG. 5 , the main teeth 52 of the main stator core 50 are prismatic. That is, the main teeth 52 have planar axial faces 54, 55 on both axial sides. The main teeth 52 also have planar circumferential faces 56, 57 on both circumferential sides. The axial faces 54, 55 are faces oriented in the axial direction. The circumferential faces 56, 57 are faces oriented in the circumferential direction. The axial faces 54, 55 and the circumferential faces 56, 57 are directly continuous with each other in the winding direction. A corner 58 is formed at the boundary between the axial face 54 on one axial side and the circumferential faces 56, 57. A corner 59 is formed at the boundary between the axial face 55 on the other axial side and the circumferential faces 56, 57.

[0020] As shown in FIG. 6 , an R-portion forming member 60 is attached to the main stator core portion 50. In this embodiment, the R-portion forming member 60 is a press-formed product obtained by press-forming an electromagnetic steel plate. The R-portion forming member 60 has a plate-shaped back yoke portion 61 that corresponds to the back yoke portion 51 of the main stator core portion 50. A plate-shaped axial surface 64 that extends radially is formed at the circumferential center of the back yoke portion 61. The axial surface 64 is capable of surface contact with the axial surface 54 of the main stator core portion 50. A flat-plate-shaped widened portion 63 that corresponds to the widened portion 63 of the main stator core portion 50 is formed at the radial inner end of the axial surface 64.

[0021] Slits 64a extending from both circumferential sides toward the circumferential center are formed on both radial sides of the axial surface 64. R-shaped portions 71 protruding to one axial side are formed on both circumferential sides of the axial surface (first surface) 64 in correspondence with the positions of the slits 64a. The R-shaped portions 71 are semicircular.

[0022] In the circumferential direction, circumferential surfaces (second surfaces) 66, 67 are formed from the outer ends of the respective R portions 71, extending toward the other axial direction. The circumferential surfaces 66, 67 are formed to have substantially the same size as the circumferential surfaces 56, 57 of the main stator core portion 50. The circumferential surfaces 66, 67 are capable of surface contact with the circumferential surfaces 56, 57. R portions 72 are formed at the other axial ends of the circumferential surfaces 66, 67, protruding toward the other axial direction. The R portions 72 are semicircular. The R portions 72 protrude toward the other axial direction from the axial surfaces 55. In the circumferential direction, an abutment surface 65 is formed at the inner end of the R portions 72, which is capable of surface contact with the axial surfaces 55 of the main stator core portion 50.

[0023] FIG. 7 is a diagram showing an example of a method for assembling the stator segments 23. In FIG. In this embodiment, a plurality of electromagnetic steel plates are laminated to form a block-shaped main stator core portion 50. The electromagnetic steel plates are press-formed to form a bent plate-shaped R portion forming member 60.

[0024] The R-portion-forming member 60 is expanded starting from the R portion 71 on one axial side so as to separate the circumferential surfaces 66, 67. As a result, the distance between the circumferential surfaces 66, 67 on the other axial end side is wider than the distance between the main teeth 52 of the main stator core portion 50, and the main teeth 52 are inserted between the circumferential surfaces 66, 67. When the R-portion-forming member 60 is pressed into the main stator core portion 50 and the R portion 72 and the abutment surface 65 on the other axial end side of the R-portion-forming member 60 clear the circumferential surfaces 56, 57, the circumferential surfaces 66, 67 of the R-portion-forming member 60 elastically restore their original shape, and the R portion 72 and the abutment surface 65 move onto the axial surface 55 on the other side. Therefore, the R-portion-forming member 60 is caught on the main stator core portion 50 by the R portion 72 and the abutment surface 65.

[0025] 5, an axial surface 64 of the R-portion forming member 60 is in surface contact with an axial surface 54 of the main stator core portion 50. Furthermore, a circumferential surface 66 of the R-portion forming member 60 is in surface contact with a circumferential surface 56 of the main stator core portion 50. Furthermore, a circumferential surface 67 of the R-portion forming member 60 is in surface contact with a circumferential surface 57 of the main stator core portion 50. Then, a contact surface 65 of the R-portion forming member 60 is in surface contact with an axial surface 55 of the main stator core portion 50.

[0026] Furthermore, the R portions 71 on one axial side are positioned so as to cover the corners 58 of the main teeth 52 of the main stator core portion 50. The R portions 72 on the other axial side are positioned so as to cover the corners 59 of the main teeth 52 of the main stator core portion 50. As a result, the R portions 71 on one axial side form the R portions 49 of the axial surfaces 44 of the teeth 42. Furthermore, the R portions 72 on the other axial side form the R portions 49 of the axial surfaces 45 of the teeth 42. In other words, the stator core portion 40 and the R portions 49 are formed by attaching the bent plate-shaped R portion-forming member 60 to the block-shaped main stator core portion 50.

[0027] The teeth portion 42 of the stator core portion 40 is formed by the main teeth portion 52 of the main stator core portion 50, and the axial surface 64, circumferential surfaces 66, 67, abutment surface 65, and R portions 71, 72 of the R portion forming member 60 arranged around the main teeth portion 52.

[0028] Coils 22 are wound around the teeth 42. The coils 22 are wound around the teeth 42 in a predetermined manner. That is, the coils 22 are wound around the teeth 42 while being shifted in the radial direction, and are then wound so as to overlap the wound coils 22. In this way, the coils 22 are wound in multiple stages.

[0029] In this embodiment, the coil 22 is wound while contacting the rounded portions 71 and 72, and therefore does not come into contact with the corners 58 and 59 of the main teeth 52. This makes it difficult for a large force to act locally on the coil 22, and the coil 22 is wound in a state where excessive load is prevented from being applied to the coil 22. In this way, the stator segment 23 is assembled.

[0030] Furthermore, even if the circumferential surfaces 66, 67 are deformed, for example, to a widened state, during assembly of the R-portion forming member 60, the tension generated when winding the coil 22 presses the circumferential surfaces 66, 67 against the main teeth portion 52. Therefore, the R-portion forming member 60 can be easily assembled to the main stator core portion 50 with the deformation of the circumferential surfaces 66, 67 eliminated.

[0031] In this embodiment, the rounded portions 49 are formed not on the circumferential surfaces 46, 47 but on the axial surfaces 44, 45, which have shorter lengths in the winding direction of the coil 22 than the circumferential surfaces 46, 47. The axial surfaces 44, 45 are more likely to receive stress from the coil 22. Therefore, by forming the rounded portions 49 on the axial surfaces 44, 45 side, it is possible to reliably prevent strong interference between the coil 22 and the corners of the core portion.

[0032] In particular, in this embodiment, the R-portion forming member 60 is a press-formed product of an electromagnetic steel sheet. Therefore, the heat resistance temperature of the R-portion forming member 60 is higher than when the material of the R-portion forming member 60 is resin. Therefore, the usable temperature range of the electric motor 1 can be widened without being affected by the material of the R-portion forming member 60.

[0033] As described above, according to the first embodiment to which the present invention is applied, in an electric motor 1 equipped with a stator 20 having teeth 42 around which coils 22 are wound, the teeth 42 have axial surfaces 44, 45 that are surfaces oriented in the axial direction of the electric motor 1, and circumferential surfaces 46, 47 that are continuous with the axial surfaces 44, 45 and are surfaces oriented in the circumferential direction of the electric motor 1, and an R portion 49 that bulges toward the coil 22 and contacts the coil 22 is formed at the boundary between the axial surfaces 44, 45 and the circumferential surfaces 46, 47. According to this configuration, rounded portions 49 are formed at the boundaries between the axial surfaces 44, 45 and the circumferential surfaces 46, 47 of the teeth 42, so that when the coil 22 is wound around the teeth 42, the coil 22 is wound in contact with the rounded portions 49, making it difficult for the coil 22 to receive localized force from the teeth 42. Therefore, it is possible to provide an electric motor 1 in which the application of an excessive load to the coil 22 is suppressed.

[0034] In this embodiment, the tooth portion 42 has a main tooth portion 52 located on the winding axis O22 side of the coil 22, and an R portion forming member 60 interposed between the main tooth portion 52 and the coil 22, and the R portion forming member 60 has an axial surface 64 that contacts one axial surface 54 of the main tooth portion 52 in the direction of the motor shaft 32, circumferential surfaces 66, 67 that are continuous from the axial surface 64 and are surfaces oriented in the circumferential direction of the electric motor 1, and R portions 71, 72. According to this configuration, by forming the R-portion forming member 60 having the R-portions 71, 72 into a U-shape that is open on the other axial side when viewed in the axial direction of the winding axis O22 of the coil 22, the circumferential surfaces 66, 67 of the R-portion forming member 60 can be opened in the circumferential direction of the electric motor 1 and easily attached to the main teeth 52. Therefore, the R-portion forming member 60 can easily provide the R-portion 49 on the teeth 42.

[0035] In this embodiment, the axial surfaces 44, 45 have a shorter length in the winding direction of the coil 22 than the circumferential surfaces 46, 47, and the rounded portion 49 bulges out in the axial direction at the axial surfaces 44, 45. According to this configuration, by forming rounded portions 49 on the axial surfaces 44 and 45 sides that are susceptible to stress from coil 22, strong interference between coil 22 and the corners of teeth 42 can be reliably prevented.

[0036] In this embodiment, the R-portion forming member 60 is made of a magnetic material. According to this configuration, the amount of magnetic flux that can pass through the tooth portion 42 can be increased compared to when the material of the R-portion forming member 60 is resin, thereby improving the output of the electric motor 1.

[0037] [Second embodiment] A second embodiment to which the present invention is applied will be described below. In this second embodiment, parts configured in the same manner as in the first embodiment will be given the same reference numerals and descriptions thereof will be omitted.

[0038] Fig. 8 is a cross-sectional view of a stator segment 223 according to the second embodiment of the present invention. Fig. 8 corresponds to Fig. 5 of the first embodiment. A stator segment 223 according to the second embodiment has an R-portion forming member (intervening member) 260 instead of the R-portion forming member 60 of the first embodiment. The R-portion forming member 260 of the second embodiment differs from the R-portion forming member 60 in that the R-portion 271 on one axial side is formed on the circumferential surfaces 66, 67 rather than on the axial surface 64.

[0039] That is, the R portion 271 is formed at one axial end of the circumferential surfaces 66, 67. The R portion 271 is formed in a semicircular shape that protrudes in the circumferential direction. When viewed in the radial direction, the R portion 271 is formed in a semicircular shape that smoothly curves from the axial surface 64. In other words, when viewed in the radial direction, the R portion 271 is connected flush with the axial surface 64.

[0040] In the second embodiment, the coil 22 is also wound while being in contact with the rounded portions 271 and 72, and therefore, the coil 22 is wound in a state in which application of an excessive load to the coil 22 is suppressed.

[0041] Therefore, in the second embodiment, as in the first embodiment, it is possible to provide an electric motor 1 in which application of an excessive load to the coil 22 is suppressed.

[0042] In particular, in this embodiment, the rounded portion 49 bulges out in the circumferential direction of the electric motor 1 on the circumferential surfaces 46, 47. According to this configuration, an increase in the axial width of the electric motor 1 when the coils 22 are wound around the teeth 42 can be suppressed, and the stator 20 can be made compact in the axial direction.

[0043] [Third embodiment] A third embodiment to which the present invention is applied will be described. In this third embodiment, parts configured in the same manner as in the first or second embodiment will be given the same reference numerals and descriptions thereof will be omitted.

[0044] Fig. 9 is a cross-sectional view of a stator segment 323 according to the third embodiment of the present invention. Fig. 9 corresponds to Fig. 5 of the first embodiment. A stator segment 323 according to the third embodiment has an R-portion forming member (intervening member) 360 instead of the R-portion forming member 60 of the first embodiment. The R-portion forming member 360 of the third embodiment differs from the R-portion forming member 60 in that the R-portion 371 on one axial side is formed so as to straddle the axial surface 64 and the circumferential surfaces 66, 67.

[0045] The rounded portion 371 is formed in an arc shape that protrudes in the axial and circumferential directions.

[0046] In the third embodiment, the coil 22 is also wound while being in contact with the rounded portions 371 and 72, and therefore, the coil 22 is wound in a state in which application of an excessive load to the coil 22 is suppressed.

[0047] Therefore, in the third embodiment, as in the first embodiment, it is possible to provide an electric motor 1 in which application of an excessive load to the coil 22 is suppressed.

[0048] [Fourth embodiment] A fourth embodiment to which the present invention is applied will be described. In this fourth embodiment, parts configured in the same manner as in the first to third embodiments will be given the same reference numerals and descriptions thereof will be omitted.

[0049] Fig. 10 is a cross-sectional view of a stator segment 423 according to a fourth embodiment of the present invention. Fig. 10 corresponds to Fig. 5 of the first embodiment. A stator segment 423 according to the fourth embodiment has an R-portion forming member (intervening member) 460 instead of the R-portion forming member 60 of the first embodiment. The R-portion forming member 460 of the fourth embodiment differs from the R-portion forming member 60 in that a second R-portion 474 is formed between a pair of R-portions 71 on one axial side.

[0050] The second R portion 473 is formed on the axial surface 64. The second R portion 271 is formed in an arc shape that protrudes to one side in the axial direction. The second R portion 473 is formed to protrude a little more than the R portion 71.

[0051] In the fourth embodiment, the coil 22 is also wound while being in contact with the rounded portions 71 and 72, and therefore, the coil 22 is wound in a state in which application of an excessive load to the coil 22 is suppressed. Furthermore, the coil 22 is wound between the pair of R portions 71 so as to be farther away from the main teeth 52 than the contact portion with the pair of R portions 71. In this case, the second R portion 473 between the pair of R portions 71 protrudes more than the R portion 71, so that the coil 22 is likely to come into surface contact with the second R portion 473.

[0052] Here, if the second R portion 273 is not formed, the coil 22 is pulled and wound between the pair of R portions 71, and therefore the coil 22 only comes into contact with the R portions 71. For this reason, heat conduction from the coil 22 tends to occur only from the contact points with the pair of R portions 71. In contrast, in this embodiment, the second R portion 473 also comes into contact with the coil 22, increasing the contact area. Therefore, heat from the coil 22 is more easily transferred to the R portion-forming member 60, and heat dissipation from the coil 22 is more easily improved. In addition, stress during winding of the coil 22 is also more easily alleviated.

[0053] Therefore, in the fourth embodiment, as in the first embodiment, it is possible to provide an electric motor 1 in which application of an excessive load to the coil 22 is suppressed.

[0054] In particular, in this embodiment, a second R portion 473 that bulges out toward the coil 22 and comes into contact with the coil 22 is formed between the two R portions 71 . According to this configuration, the contact area with the coil 22 can be increased, and the heat generated by the coil 22 can be easily transferred to the outside via the rounded portion forming member 60.

[0055] [Fifth embodiment] A fifth embodiment to which the present invention is applied will be described below. In this fifth embodiment, parts configured in the same manner as in the first to fourth embodiments will be given the same reference numerals and descriptions thereof will be omitted.

[0056] Fig. 11 is a cross-sectional view of a stator segment 523 according to a fifth embodiment of the present invention. Fig. 11 corresponds to Fig. 8 of the second embodiment. A stator segment 523 according to the fifth embodiment has an R-portion forming member (intervening member) 560 instead of the R-portion forming member 260 of the second embodiment. The R-portion forming member 560 of the fifth embodiment differs from the R-portion forming member 260 of the second embodiment in that the R-portion 572 on the other axial side is formed on the circumferential surfaces 66, 67 rather than on the abutment surface 65 corresponding to the axial surface.

[0057] That is, the R portion 572 is formed at the other axial end of the circumferential surfaces 66, 67. The R portion 572 is formed in a semicircular shape that protrudes in the circumferential direction. The R portion 572 is formed in a semicircular shape that smoothly curves from the abutment surface 65 when viewed in the radial direction. In other words, the R portion 572 is connected flush with the abutment surface 65 when viewed in the radial direction.

[0058] In the fifth embodiment, the coil 22 is also wound while being in contact with the rounded portions 271 and 572, and therefore, the coil 22 is wound in a state in which application of an excessive load to the coil 22 is suppressed.

[0059] Also in the fifth embodiment, second R portions 573, 574, 575 may be appropriately formed between a pair of adjacent R portions 271, 572 to increase the contact area between the coil 22 and the R portion forming member 560.

[0060] Therefore, in the fifth embodiment, as in the first embodiment, it is possible to provide an electric motor 1 in which application of an excessive load to the coil 22 is suppressed.

[0061] [Other embodiments] The above-described embodiment merely shows one aspect of the present invention, and any modifications and applications are possible without departing from the spirit of the present invention.

[0062] In the above embodiment, the main stator core portion 50 is configured in a block shape by stacking electromagnetic steel plates, but instead, the main stator core portion 50 may be a powder magnetic core formed by solidifying powdered magnetic material.

[0063] In the above embodiment, the R-portion forming member 60 is a press-molded product formed by press-molding an electromagnetic steel plate, but instead, the R-portion forming member 60 may be a resin-molded product formed by injection molding a resin.

[0064] In the above embodiment, the stator core portion 40 is described as being formed by combining the main stator core portion 50 and the R-portion forming members 60, 260, 360, 460, 560, but it may also be an integral structure. That is, for example, the stator core portion 40 may be integrally molded by solidifying powdered magnetic material, and the R portion 49 may also be integrally formed.

[0065] In the above embodiment, the rounded portions 49, 71, 72, 271, 371, 572 and the second rounded portions 473, 573, 574, 575 are configured to be arc-shaped, but are not limited thereto. For example, the rounded portions 49 to 572 and the second rounded portions 473 to 575 may have any shape as long as they are smoothly curved, and may be, for example, a bulging shape.

[0066] [Configuration supported by the above embodiment] The above embodiment supports the following configurations.

[0067] (Configuration 1) A motor having a stator having a core portion around which a coil is wound, the core portion having a first surface that is a surface oriented in the direction of the rotation axis of the motor, and a second surface that is continuous with the first surface and oriented in the circumferential direction of the motor, characterized in that an R portion that bulges toward the coil and contacts the coil is formed at the boundary between the first surface and the second surface. With this configuration, an R portion is formed at the boundary between the first and second surfaces of the core, so when the coil is wound around the core, the coil comes into contact with the R portion and is wound around the core, making it difficult for the coil to receive localized force from the core.As a result, it is possible to provide a motor in which excessive load is prevented from being applied to the coil.

[0068] (Configuration 2) The motor described in Configuration 1, characterized in that the core portion has a main core portion located on the winding axis side of the coil and an intervening member interposed between the main core portion and the coil, and the intervening member has the first surface that contacts one surface of the main core portion in the rotation axis direction, the second surface that is continuous from the first surface and faces in the circumferential direction of the motor, and the R portion. According to this configuration, the intervening member having the R portion is formed in a U-shape with the other side in the rotation axis direction open when viewed in the direction of the coil winding axis, so that the second surface of the intervening member opens in the circumferential direction of the motor and can be easily attached to the main core portion. Therefore, the intervening member can easily provide the R portion to the core portion.

[0069] (Configuration 3) The motor described in configuration 1 or 2, characterized in that the first surface has a shorter length in the winding direction of the coil than the second surface, and the R portion bulges out in the direction of the rotation axis on the first surface. According to this configuration, by forming the rounded portion on the first surface side which is more likely to receive stress from the coil, it is possible to reliably prevent strong interference between the coil and the corners of the core portion.

[0070] (Configuration 4) The motor according to configuration 1 or 2, wherein the R portion bulges out in the circumferential direction of the motor on the second surface. With this configuration, it is possible to prevent the width of the motor in the axial direction from increasing when the coil is wound around the core portion, thereby making it possible to make the stator compact in the axial direction of the motor.

[0071] (Configuration 5) The motor according to any one of configurations 1 to 4, characterized in that a second R portion is formed between the two R portions, bulging toward the coil and contacting the coil. According to this configuration, the contact area with the coil can be increased, making it easier to transfer heat generated by the coil to the outside via the intervening member.

[0072] (Configuration 6) The motor according to configuration 2, wherein the intervening member is a magnetic material. With this configuration, the amount of magnetic flux that can pass through the core portion can be increased compared to when the intervening member is made of resin, thereby improving the output of the motor. [Explanation of symbols]

[0073] 1 Electric motor (motor) 20 Stator 22 coils 42 Teeth part (core part) 44 Axial surface (first surface) 45 Axial surface (first surface) 46 Circumferential surface (2nd surface) 47 Circumferential surface (2nd surface) 49 R section 52 Teeth part (main core part) 54 Axial surface (one side in the direction of the rotation axis) 60 R section forming member (intervening member) 64 Axial surface (first surface) 66 Circumferential surface (second surface) 67 Circumferential surface (2nd surface) 71 R section 72 R section 260 R-shaped parts (intermediate parts) 271 R Section 360 R forming parts (intermediate parts) 371 R Section 460 R-section forming material (intermediate material) 473 Part 2R 560 R-shaped parts (intermediate parts) 572 R Section 573 Part 2R 573 Part 2R 574 Part 2R O22 Rewind axis

Claims

1. A motor including a stator (20) having a core portion (42) around which a coil (22) is wound, The core portion (42) has a first surface (44, 45, 64) that is a surface oriented in the rotational axis direction of the motor, and a second surface (46, 47, 66, 67) that is continuous with the first surface (44, 45, 64) and is oriented in the circumferential direction of the motor, an R portion (49, 71, 72, 271, 371, 572) that bulges toward the coil (22) and contacts the coil (22) is formed at the boundary between the first surface (44, 45, 64) and the second surface (46, 47, 66, 67), Motor.

2. The core portion (42) has a main core portion (52) located on the winding axis (O22) side of the coil (22), and an intervening member (60, 260, 360, 460, 560) interposed between the main core portion (52) and the coil (22), the intervening member (60, 260, 360, 460, 560) has the first surface (64) in contact with one surface (54) of the main core portion (52) in the rotational axis direction, the second surface (66, 67) that is continuous with the first surface (64) and oriented in the circumferential direction of the motor (1), and the R portion (49, 71, 72, 271, 371, 572), The motor according to claim 1 .

3. The first surfaces (44, 45, 64) have a shorter length in the winding direction of the coil (22) than the second surfaces (46, 47, 66, 67), The R portion (49, 71, 72, 371) bulges in the rotation axis direction on the first surface (44, 45, 64), 3. The motor according to claim 1 or 2.

4. The R portion (49, 271, 371, 572) bulges in the circumferential direction of the motor (1) on the second surface (46, 47, 66, 67).

3. The motor according to claim 1 or 2.

5. A second R portion (473, 573, 574, 575) is formed between the two R portions (49, 71, 72, 271, 371, 572), bulging toward the coil (22) and contacting the coil (22).

3. The motor according to claim 1 or 2.

6. The intervening member (60, 260, 360, 460, 560) is a magnetic material. The motor according to claim 2 .

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