Stator and motor

Abstract

Provided are a stator and a motor capable of improving thermal conductivity of insulating parts while maintaining the strength of the insulating parts. A stator (1) comprises a stator core and insulating parts (3) formed integrally with the stator core. A plurality of teeth (5) included in the stator core protrude in the radial direction (12). Each of the plurality of teeth (5) has: a tooth end surface that is positioned at an end in the axial direction (91); and a tooth lateral surface that is positioned at an end in the circumferential direction (13). The insulating parts each have: a high-strength insulating section (6) that covers the boundary part between the tooth end surface and the tooth lateral surface; and a high-thermal-conductivity insulating section (7) that covers the tooth lateral surface. The strength of the high-strength insulating section (6) is greater than the strength of the high-thermal-conductivity insulating section (7). The thermal conductivity of the high-thermal-conductivity insulating section (7) is greater than the thermal conductivity of the high-strength insulating section (6).

Description

Stator and motor

[0001] The present disclosure relates to a stator and a motor. More specifically, it relates to a stator including a stator core and an insulating portion, and a motor including this stator.

[0002] Patent Document 1 describes a motor including a core having a tooth portion with a substantially rectangular cross section, an insulating insulator covering the tooth portion, and a coil portion formed on the tooth portion via the insulator. In this motor, the insulator is composed of a plurality of insulating materials having different thermal conductivities, and a high thermal conductivity material is used in at least a portion covering the corner of the tooth portion in the insulator.

[0003] Japanese Patent Application Laid-Open No. 2010-57211

[0004] However, in the motor described in Patent Document 1, a high thermal conductivity material is used in a portion covering the corner of the tooth portion, and it is difficult to ensure the strength of this portion. Also, a gap is formed between the insulator and the tooth portion, and it is difficult to ensure the strength and thermal conductivity of the insulator and the tooth portion.

[0005] An object of the present disclosure is to provide a stator and a motor capable of improving the thermal conductivity of an insulating portion (insulator) while maintaining the strength of the insulating portion.

[0006] A stator according to one aspect of the present disclosure comprises a stator core and an insulating portion formed integrally with the stator core. The axial direction is defined as the direction in which the axis, which is the rotation center of the rotor facing the stator core, extends. The stator core has a yoke and a plurality of teeth. The plurality of teeth protrude from the yoke toward the rotor. The plurality of teeth protrude in different radial directions perpendicular to the axis. Each of the plurality of teeth has a tooth end face and a tooth side surface. The tooth end face is located at the end in the axial direction. The tooth side surface is located at the end in the circumferential direction perpendicular to the axial and radial directions. The insulating portion has a high-strength insulating portion and a high-thermal-conductivity insulating portion. The high-strength insulating portion has a boundary covering portion and a wall portion. The boundary covering portion covers the boundary between the tooth end face and the tooth side surface. The wall portion extends from the radial end of the tooth end face toward the tooth in the axial direction. The high thermal conductivity insulating section has a side covering section that covers the teeth side. The strength of the high-strength insulating section is greater than the strength of the high thermal conductivity insulating section. The thermal conductivity of the high thermal conductivity insulating section is greater than the thermal conductivity of the high-strength insulating section.

[0007] Another aspect of the present disclosure is an inner-rotor type motor comprising a stator as described above and a rotor disposed on the inner circumference of the stator.

[0008] A motor according to another aspect of the present disclosure comprises a stator and a rotor as described above. The stator core of the stator is divided in the circumferential direction.

[0009] A motor according to yet another aspect of this disclosure comprises a stator and a rotor as described above. The stator core of the stator is integrally formed.

[0010] In the stator and motor of this disclosure, the thermal conductivity of the insulating portion can be improved while maintaining the strength of the insulating portion.

[0011] Figure 1 is a perspective view of a stator according to one embodiment. Figure 2 is a cross-sectional view of a motor having a stator according to one embodiment. Figure 3 is a perspective view of a stator segment of a stator according to one embodiment. Figure 4 is a perspective view of a stator core unit segment of a stator segment according to one embodiment. Figure 5 is a perspective view of a stator core segment of a stator according to one embodiment. Figure 6 is an end view of a stator core segment according to one embodiment, viewed from the axial direction. Figure 7 is a perspective view of an insulating section segment of a stator according to one embodiment. Figure 8 is a side view of an insulating section segment according to one embodiment, viewed from the circumferential direction. Figure 9 is a side view of an insulating section segment according to one embodiment, viewed from one radial direction. Figure 10 is a side view of an insulating section segment according to one embodiment, viewed from the axial direction. Figure 11 is a cross-sectional view of the joint between the electromagnetic steel sheet and the insulating section of a stator core segment according to one embodiment. Figure 12 is a cross-sectional view of the insulating section according to one embodiment.

[0012] (One Embodiment) (1) Overview The stator and motor relating to this disclosure will be described below. The embodiments described below are only a part of the various embodiments of this disclosure, and various modifications are possible in the following embodiments depending on the design, etc., as long as the objectives of this disclosure can be achieved.

[0013] Figure 1 is a perspective view of a stator 1 according to one embodiment of the present disclosure. Figure 2 is a cross-sectional view of a motor 8 having the stator 1 according to one embodiment. Figure 3 is a perspective view of a stator segment 1A constituting the stator 1 according to one embodiment. Figure 4 is a perspective view of a stator core unit segment 10A within the stator segment 1A according to one embodiment. Figure 5 is a perspective view of a stator core segment 2A having in the stator 1 according to one embodiment.

[0014] As shown in Figures 1, 3, and 5, the stator 1 according to this disclosure comprises a stator core 2 and an insulating portion 3 integrally formed with the stator core 2. The axial direction 91 is defined as the direction in which the axis 90, which is the rotation center of the rotor 9 (Figure 2) facing the stator core 2, extends. The stator core 2 has a yoke 21 and a plurality of teeth 5. Each of the plurality of teeth 5 protrudes from the yoke 21 toward the rotor 9. The plurality of teeth 5 protrude in different radial directions 12 perpendicular to the axis 90. Each tooth 5 has a tooth end face 51 and a tooth side surface 52. The tooth end face 51 is located at the end in the axial direction 91. The tooth side surface 52 is located at the end in the circumferential direction 13, which is perpendicular to the axial direction 91 and the radial direction 12 and is along the circumference of a circle centered on the axis 90. As shown in Figures 3 and 4, the insulating portion 3 has a high-strength insulating portion 6 and a high-thermal-conductivity insulating portion 7. As shown in Figure 4, the high-strength insulating portion 6 has a boundary covering portion 61 and a wall portion 62. The boundary covering portion 61 covers the boundary portion 53 between the tooth end face 51 and the tooth side surface 52. The wall portion 62 extends from the end of the tooth end face 51 in the radial direction 12 toward the tooth 5 in the axial direction 91. The high-thermal-conductivity insulating portion 7 has a side covering portion 71 that covers the tooth side surface 52. The strength of the high-strength insulating portion 6 is greater than the strength of the high-thermal-conductivity insulating portion 7. The thermal conductivity of the high-thermal-conductivity insulating portion 7 is greater than the thermal conductivity of the high-strength insulating portion 6.

[0015] Furthermore, the motor 8 according to this disclosure is an inner rotor type, comprising the stator 1 described above and a rotor 9 arranged on the inner circumference of the stator 1.

[0016] Furthermore, the motor 8 according to this disclosure comprises the stator 1 and the rotor 9 described above. The stator core 2 of the stator 1 is divided in the circumferential direction 13.

[0017] Furthermore, the motor 8 according to this disclosure comprises the stator 1 and the rotor 9 described above. The stator core 2 of the stator 1 is formed integrally.

[0018] In the stator 1 and motor 8 described above, the thermal conductivity of the insulating portion 3 can be improved while maintaining the strength of the insulating portion 3.

[0019] (2) Details (2.1) Motor As shown in Figure 2, the motor 8 comprises a stator 1 and a rotor 9. The motor 8 in this embodiment is an inner rotor type motor comprising a stator 1 and a rotor 9 arranged on the inner circumference of the stator 1.

[0020] The rotor 9 has a rotation axis 92 and rotates around an axis 90, which is located at the center of the rotation axis 92 and is the center of rotation of the rotor 9. The rotor 9 faces the stator 1.

[0021] Here, the direction in which the axis 90 extends is defined as the axial direction 91. The direction passing through the axis 90 and perpendicular to the axial direction 91 is defined as the radial direction 12. The direction perpendicular to the axial direction 91 and the radial direction 12, and along the circumference of the circle centered on the axis 90, is defined as the circumferential direction 13.

[0022] The rotor 9 has a cylindrical rotor core 93, a plurality of magnets 94 (12 in this embodiment), and a rotating shaft 92. The rotating shaft 92 is held on the inner circumference of the rotor core 93. The plurality of magnets 94 are arranged to form a polygon.

[0023] In the motor 8, the magnetic flux generated from multiple coils 4 (18 in this embodiment) in the stator 1 generates an electromagnetic force that rotates the rotor 9.

[0024] (2.2) Stator As shown in Figure 1, the stator 1 comprises a stator core 2 and an insulating part 3 formed integrally with the stator core 2. As shown in Figure 2, the stator core 2 has a yoke 21 and a plurality of teeth 5 (18 in this embodiment). The stator 1 also comprises a plurality of coils 4. Furthermore, as shown in Figure 1, the stator 1 further comprises a plurality of busbars 11.

[0025] As shown in Figure 2, in this embodiment, the stator 1 is divided into a plurality (18 in this embodiment) of stator segments 1A in the circumferential direction 13, and the stator segments 1A are connected in the circumferential direction 13 to constitute the stator 1.

[0026] (2.3) Stator Core As shown in Figure 2, the stator core 2 has a yoke 21 and a plurality of teeth 5. In other words, the yoke 21 and the plurality of teeth 5 constitute the stator core 2. In this embodiment, the stator core 2 is divided into a plurality of stator core segments 2A in the circumferential direction 13, and the stator core segments 2A are connected in the circumferential direction 13 to constitute the stator core 2. The yoke 21 has an annular shape when a plurality of yoke segments 21A are connected in the circumferential direction 13. One stator core segment 2A is composed of one yoke segment 21A and one tooth 5.

[0027] Multiple teeth 5 protrude from the yoke 21 toward the rotor 9 (more precisely, toward the axis 90 of the rotor 9). In this embodiment, each of the multiple teeth 5 is provided with teeth 5 that protrude from the yoke 21 in the respective radial direction 12 (see Figure 3) at a pitch of 20 degrees in the circumferential direction 13.

[0028] Figure 6 is an end view of a stator core segment 2A as seen from the axial direction 91 according to one embodiment. As shown in Figures 5 and 6, the teeth 5 have a tooth end face 51, a tooth side surface 52, and a protruding surface 54. The tooth end face 51 is located at the end in the axial direction 91. In this embodiment, the tooth end face 51 is a flat surface, and a total of two tooth end faces 51 are provided at each end of the axial direction 91. The tooth side surface 52 is located at the end in the circumferential direction 13. In this embodiment, the tooth side surface 52 is a flat surface, and tooth end faces 51 are provided at each end of the circumferential direction 13. The protruding surface 54 is located at the end facing the axis 90 in the radial direction 12.

[0029] In this embodiment, the boundary 53 between the tooth end face 51 and the tooth side surface 52 is formed by the intersection line (ridge line) of the tooth end face 51 and the tooth side surface 52, since the tooth end face 51 and the tooth side surface 52 are flat.

[0030] At the boundary between the tooth side surface 52 and the protruding surface 54, a retaining projection 55 is formed that protrudes circumferentially 13 from the end of the tooth side surface 52 near the protruding surface 54, so that the protruding surface 54 extends in the circumferential direction 13. The retaining projection 55 prevents the coil 4, which is wound around one tooth 5 via the insulating portion 3, from coming out radially 12.

[0031] As shown in Figure 5, a fitting projection 25 is formed on one end face of the yoke 21 of the stator core segment 2A in the circumferential direction 13, and a fitting recess 26 is formed on the other end face. The fitting recess 26 of one stator core segment 2A is fitted into the fitting projection 25 of the other stator core segment 2A, thereby connecting the two adjacent stator core segments 2A. By repeating this connection, an annular yoke 21 (stator core 2) is formed as shown in Figure 2.

[0032] In this embodiment, the stator core 2 is constructed by laminating a plurality of electromagnetic steel sheets 23 (see Figure 11). In the stator core 2, a yoke section 21A and one tooth 5 are integrally formed for each stator core section 2A.

[0033] (2.4) Insulation Figure 7 is a perspective view of the insulating section 3A of the stator 1 according to one embodiment. Figure 8 is a side view of the insulating section 3A according to one embodiment as seen from the circumferential direction 13. Figure 9 is a side view of the insulating section 3A according to one embodiment as seen from the radial direction. Figure 10 is a side view of the insulating section 3A according to one embodiment as seen from the axial direction 91.

[0034] As shown in Figure 3, the insulating portion 3 is interposed between the stator core 2 and the coil 4 to electrically insulate the stator core 2 and the coil 4. The insulating portion 3 is formed of a resin material which is an insulator. In this embodiment, as the stator core 2 (stator 1) is divided into a plurality of stator core divisions 2A (stator divisions 1A) in the circumferential direction 13, the insulating portion 3 is composed of a plurality of insulating portion divisions 3A corresponding to each of the plurality of stator core divisions 2A (stator divisions 1A). As shown in Figures 7 to 9, the insulating portion 3 has a high-strength insulating portion 6 and a high-thermal-conductivity insulating portion 7.

[0035] (2.4.1) High-strength insulating section The high-strength insulating section 6 is formed in the part of the insulating section 3 where a large force is applied from the coil 4, so as to prevent damage to the insulating section 3 (high-strength insulating section 6) when the coil 4 is wound around it. Here, "large force" refers to the largest (or above average) force among the forces that the insulating section 3 receives from the coil 4. As shown in Figure 7, the high-strength insulating section 6 has a boundary covering section 61, a wall section 62, and an end-face covering section 63.

[0036] The boundary covering portion 61 covers the boundary portion 53 between the tooth end face 51 and the tooth side surface 52. The boundary portion 53 is the ridge line between the tooth end face 51 and the tooth side surface 52, and the boundary covering portion 61 is formed in a region having a predetermined width on both the tooth side surface 52 and the tooth end face 51, centered on the boundary portion 53 which is made up of the ridge line. In this embodiment, a total of four boundary covering portions 61 are provided on the insulating portion divided body 3A.

[0037] The portion of the insulating portion 3 corresponding to the boundary portion 53 is a part of the insulating portion 3 that is prone to damage because it comes into contact with the coil 4 wound around the teeth 5 and receives a large force from the coil 4. For this reason, a boundary cover portion 61, which is a high-strength insulating portion 6, is provided to cover the boundary portion 53, which requires high strength. Here, "high strength" refers to the highest (or above average) strength among the required strength (destruction resistance, resistance to breakage) within the insulating portion 3.

[0038] The end face covering portion 63 is provided so as to cover the tooth side surface 52. In this embodiment, the end face covering portion 63 is provided between both boundary covering portions 61 of one of the tooth end faces 51 at both ends in the axial direction 91, and a total of two end face covering portions 63 are provided for one insulating portion 3. The end face covering portion 63 and the boundary covering portions 61 on both sides are formed integrally. In this case, the entire portion corresponding to the tooth end face 51 may be made into the end face covering portion 63, and the boundary portion 53 consisting of a ridge and the portion corresponding to the tooth side surface 52 may be made into the boundary covering portion 61. Alternatively, as described above, the portion corresponding to a region having a predetermined width on both the tooth side surface 52 and the tooth end face 51 with the boundary portion 53 consisting of a ridge as the center may be made into the boundary covering portion 61, and only the portion in between (i.e., a part of the portion corresponding to the tooth end face 51) may be made into the end face covering portion 63.

[0039] Furthermore, the end face covering portion 63 is not subjected to as great a force as the boundary covering portion 61. For this reason, the end face covering portion 63 does not require high strength, but because the end face covering portion 63 can integrally connect both boundary covering portions 61 that sandwich the end face covering portion 63 in the circumferential direction 13, the end face covering portion 63, together with the boundary covering portion 61, constitutes a high-strength insulating portion 6.

[0040] The wall portion 62 extends from the end of the tooth end face 51 in the radial direction 12 toward one tooth 5 in the axial direction 91. Specifically, the wall portion 62 is formed as an inner wall portion 621 projecting in the axial direction 91 from the end of the radial direction 12 toward the axis 90, and an outer wall portion 622 projecting in the axial direction 91 from the end of the radial direction 12 toward the opposite axis 90. Furthermore, the inner wall portion 621 is formed as an inner wall portion 621 projecting to one side of the axial direction 91 and an inner wall portion 621 projecting to the other side. Similarly, the outer wall portion 622 is formed as an outer wall portion 622 projecting to one side of the axial direction 91 and an outer wall portion 622 projecting to the other side. The wall portion 62 requires high strength to resist the force when the coil 4 moves and receives force from the coil 4, thereby preventing the coil 4 from falling off.

[0041] (2.4.2) High thermal conductivity insulating part The high thermal conductivity insulating part 7 is formed in a part of the insulating part 3 where no large force is applied from the coil 4 (that is, where high strength is not required). As shown in FIG. 7, the high thermal conductivity insulating part 7 has a side covering part 71 that covers the tooth side surface 52, and flange parts 72 that project in the circumferential direction 13 from both ends in the radial direction 12 of the side covering part 71. As described above, since the boundary covering part 61 has a predetermined width from the boundary part 53 formed of a ridge line to the tooth side surface 52, the side covering part 71 covers only a part of the tooth side surface 52 (that is, a part of the tooth side surface 52) excluding the part covered by the boundary covering part 61 at both ends in the axial center direction 91. The side covering part 71 integrally connects both boundary covering parts 61 that sandwich the side covering part 71 in the axial center direction 91. The flange part 72 is continuous with the inner wall part 621 and the outer wall part 622.

[0042] (2.4.3) Material of the insulating part FIG. 12 is a cross-sectional view of the insulating part 3 according to an embodiment. As shown in FIG. 12, the insulating part 3 (the high-strength insulating part 6 and the high thermal conductivity insulating part 7) includes, as materials, a base resin 31, a reinforcing material 32, and a thermal conductivity filler 33. The base resin 31 has electrical insulation properties. It is preferable that the reinforcing material 32 and the thermal conductivity filler 33 also have electrical insulation properties. The reinforcing material 32 contributes to improving the strength of the insulating part 3. The thermal conductivity filler 33 contributes to improving the thermal conductivity of the insulating part 3.

[0043] Note that the reinforcing material 32 is inferior to the thermal conductivity filler 33 in contributing to the improvement of the thermal conductivity of the insulating part 3. Also, the thermal conductivity filler 33 is inferior to the reinforcing material 32 in contributing to the improvement of the strength of the insulating part 3. Also, the thermal conductivity of the reinforcing material 32 may be higher, lower, or the same as the thermal conductivity of the base resin 31. Also, the strength of the thermal conductivity filler 33 may be higher, lower, or the same as the strength of the base resin 31.

[0044] As the base resin 31, for example, thermoplastic resins such as LCP (Liquid Crystal Polymer), PBT (Poly Butylene Terephthalate), PET (Poly Ethylene Terephthalate), PA (Polyamide), etc. are preferably used, but it is not limited to these thermoplastic resins, and other thermoplastic resins can be used. Further, the base resin 31 is not limited to thermoplastic resins, and for example, thermosetting resins can be used. The base resin 31 included in the high-strength insulating portion 6 and the base resin 31 included in the high thermal conductivity insulating portion 7 are of the same type of resin material.

[0045] FIG. 11 is a cross-sectional view of the joint portion between the electromagnetic steel sheet 23 and the insulating portion 3 of the stator core 2 according to an embodiment. As shown in FIG. 11, the insulating portion 3 (high-strength insulating portion 6 or high thermal conductivity insulating portion 7) is filled in the gap 24 formed between two of the plurality of electromagnetic steel sheets 23. Further, the opposing surfaces 20 and 30 of the insulating portion 3 and the stator core 2 that face each other are joined to each other.

[0046] As shown in FIG. 12, the base resin 31 included in the high-strength insulating portion 6 and the base resin 31 included in the high thermal conductivity insulating portion 7 are integrally connected. That is, there is no interface for the base resin 31 between the high-strength insulating portion 6 and the high thermal conductivity insulating portion 7.

[0047] As the reinforcing material 32, for example, one or more types (any combination is possible) of materials such as glass fiber, carbon fiber, potassium titanate, aramid fiber, talc, mica, etc. are preferably used, but it is not limited thereto. In the present embodiment, the reinforcing material 32 included in the high-strength insulating portion 6 and the reinforcing material 32 included in the high thermal conductivity insulating portion 7 are of the same type of material (when including a plurality of types of materials, the combination of types is the same).

[0048] As the thermal conductivity filler 33, for example, Al ２ O ３One or more materials (any combination is acceptable) from among aluminum oxide, AlN (aluminum nitride), BN (boron nitride), BeO (beryllium oxide), etc. are preferably used, but are not limited to these. In this embodiment, the thermal conductive filler 33 contained in the high-strength insulating part 6 and the thermal conductive filler 33 contained in the high thermal conductivity insulating part 7 are of the same type of material (if multiple types of materials are included, the combination of types is the same).

[0049] Furthermore, the insulating portion 3 may also contain additives as appropriate. Suitable additives include, but are not limited to, flame retardants and viscosity reducers.

[0050] (2.4.4) Strength The strength of the high-strength insulating section 6 is greater than the strength of the high-thermal-conductivity insulating section 7. In this embodiment, the strength of the high-strength insulating section 6 is made greater than the strength of the high-thermal-conductivity insulating section 7 by making the content of the reinforcing material 32 in the high-strength insulating section 6 greater than the content of the reinforcing material 32 in the high-thermal-conductivity insulating section 7.

[0051] Tensile strength is the primary type of strength used to evaluate the strength of the high-strength insulating part 6 and the high-thermal-conductivity insulating part 7.

[0052] When evaluating the strength of the high-strength insulating section 6 and the high-thermal-conductivity insulating section 7 by tensile strength, a small tensile test specimen is cut from the insulating section 3, and the strength is evaluated by a so-called micro-tensile test (tensile test) which obtains the stress-strain relationship of this tensile test specimen.

[0053] Furthermore, the content may be expressed as a percentage by weight, a percentage by volume, or a ratio of other physical quantities to the total.

[0054] (2.4.5) Thermal Conductivity The thermal conductivity of the high thermal conductivity insulating section 7 is greater than that of the high strength insulating section 6. In this embodiment, the thermal conductivity of the high thermal conductivity insulating section 7 is made greater than that of the high strength insulating section 6 by increasing the content of the thermal conductive filler 33 in the high thermal conductivity insulating section 7 compared to the content of the thermal conductive filler 33 in the high strength insulating section 6.

[0055] As a method for measuring the thermal conductivity of the high-strength insulating section 6 and the high-thermal-conductivity insulating section 7, for example, the so-called xenon flash method is employed. The xenon flash method is a method in which samples of the high-strength insulating section 6 and the high-thermal-conductivity insulating section 7 are cut out from the insulating section 3, processed to be parallel and smooth, and the time response (temperature rise) of the back surface temperature of the sample when pulsed light is irradiated onto the sample is measured non-contact using an IR (infrared) detector.

[0056] (2.5) Coils As shown in Figures 1 to 3, each of the plurality of coils 4 is wound around the outer surface of one tooth 5 with an insulating portion 3 in between. The coil 4 is formed of a conductor 41. In this embodiment, 18 coils 4 are provided on the stator core 2. The cross-sectional shape of the conductor 41 is square. In this embodiment, the coil 4 is a molded coil. A molded coil in this disclosure does not include a coil in which a conductor of a constant width and thickness is simply wound in a spiral shape.

[0057] A molded coil is formed, for example, by preparing multiple rectangular sheets of material with different lengths, widths, or thicknesses, and joining these sheets together by cold pressure welding, welding, or other methods. The material of the sheets is a so-called low-resistance material such as copper or aluminum.

[0058] Alternatively, the formed coil may be formed by so-called casting, which involves melting copper or the like and pouring it into a mold. Alternatively, the formed coil may be formed by bending a plate-shaped wire, pre-formed with varying widths and thicknesses along the way, at predetermined positions. Or, the formed coil may be formed by rolling a plate-shaped wire of constant width and thickness at predetermined points, changing the width and thickness along the way, and then winding it in a spiral shape. In short, the formed coil is formed by a method that involves additional processing beyond simply winding the wire, or by a method different from simply winding.

[0059] (2.6) Busbars The busbars 11 are connected to the conductors 41. The busbars 11 make it easier to pass large currents. The busbars 11 are electrically connected to the conductors 41 of the corresponding coils 4 in order to form connections for the U phase, V phase, and W phase. The busbars 11 are positioned opposite the axis 90 of the coil 4 (i.e., further away from the coil 4 when viewed from the axis 90). In the radial direction, the busbars 11 are adjacent to the coil 4 at a position opposite the axis 90. This makes it easier to suppress an increase in the size of the stator 1 in the axial direction 91.

[0060] Furthermore, the busbar 11 is positioned adjacent to the yoke 21 in the axial direction 91. The stator 1 is composed of the stator core 2, coil 4, insulating section 3, and busbar 11.

[0061] (2.7) Stator Core Unit As shown in Figure 1, the stator core 2 and the insulating part 3 constitute the stator core unit 10. The stator core unit 10 includes the stator core 2 and the insulating part 3, but does not include the coil 4 and the busbar 11. The stator 1 includes the stator core unit 10 (stator core 2 and insulating part 3) and the coil 4.

[0062] Furthermore, as shown in Figure 4, the stator core segment 2A and the insulating segment 3A constitute the stator core unit segment 10A. The stator core unit segment 10A includes the stator core segment 2A and the insulating segment 3A, but does not include the coil 4 and the busbar 11. The stator segment 1A includes the stator core unit segment 10A (stator core segment 2A and insulating segment 3A) and the coil 4. By connecting the above-described plurality of yoke segments 21A in the circumferential direction 13, the plurality of stator core unit segments 10A are connected to form the stator core unit 10 shown in Figure 1.

[0063] (2.8) Manufacturing of the stator core unit The stator core unit 10, which consists of a stator core 2 and an insulating part 3, can be manufactured, for example, by insert molding in resin injection molding. In this case, the stator core 2 is placed as an insert in the cavity of an injection molding die, and molten resin is injected into the cavity to form an insulating part 3 that is joined to the stator core 2, thereby obtaining the molded product, the stator core unit 10.

[0064] The stator core unit 10 may also be manufactured by other methods. For example, the stator core unit 10 may be obtained by forming an insulating part 3 that is joined to the installed stator core 2 using a so-called 3D printer.

[0065] (2.9) Features As shown in Figure 4, the stator core unit segment 10A has a stator core segment 21A and an insulating part 3 which are formed integrally. Of the insulating part 3, the boundary covering part 61 and the wall part 62 that cover the boundary part 53 which requires high strength are made of high-strength insulating part 6, and the side covering part 71 that covers the tooth side surface 52 which does not require high strength is made of high-thermal-conductivity insulating part 7. The high-thermal-conductivity insulating part 7 which does not require high strength can have a lower content of reinforcing material 32 compared to the high-strength insulating part 6, and by increasing the content of thermal conductive filler 33, the thermal conductivity of the high-thermal-conductivity insulating part 7 can be improved.

[0066] Since the stator core unit 10 (stator 1) has a stator core 2 and an insulating part 3 that are formed integrally, it is possible to suppress the formation of a gap between the stator core 2 and the insulating part 3, making it easier to improve the strength and thermal conductivity of the stator core unit 10 (stator 1). Furthermore, since the insulating part 3 has a high-strength insulating part 6 and a high-thermal-conductivity insulating part 7, it is possible to improve the thermal conductivity of the insulating part 3 while maintaining the strength of the insulating part 3.

[0067] Furthermore, the stator core 2 is divided into multiple stator core segments 2A in the circumferential direction 13. This allows the coil 4 to be attached to each of the stator core segments 2A divided in the circumferential direction 13, thus facilitating the manufacture of the stator 1.

[0068] Furthermore, as shown in Figure 12, the high-strength insulating section 6 and the high-thermal-conductivity insulating section 7 include a base resin 31, a reinforcing material 32, and a thermal-conducting filler 33 as materials. This allows both strength and thermal conductivity to be adjusted simply by adjusting the content of the reinforcing material 32 and the thermal-conducting filler 33, making it easy to adjust strength and thermal conductivity.

[0069] Furthermore, since the base resin 31 included in the high-strength insulating part 6 and the base resin 31 included in the high-thermal-conductivity insulating part 7 are integrally connected, the overall strength of the insulating part 3 can be improved.

[0070] Furthermore, as shown in Figure 11, an insulating portion 3 (high-strength insulating portion 6 or high-thermal-conductivity insulating portion 7) is filled into the gap 24 formed between the electromagnetic steel sheets 23. As a result, the stator core 2 and the insulating portion 3 are firmly fixed to each other, improving the strength and thermal conductivity of the stator core unit 10 (stator 1).

[0071] Furthermore, the opposing surfaces 20 and 30 of the insulating section 3 and the stator core 2 are joined to each other. As a result, no gap is formed between the insulating section 3 and the stator core 2, improving the strength and thermal conductivity of the stator core unit 10 (stator 1).

[0072] (3) Modifications Next, modifications of this embodiment are listed. The following modifications may be implemented by combining them as appropriate.

[0073] Motor 8 is not limited to an inner rotor type motor. Motor 8 may also be an outer rotor type motor.

[0074] The busbar 11 has an arbitrary configuration and does not have to be provided on the stator 1. If the stator 1 does not have a busbar 11, for example, the coils 4 (conductors 41) may be connected to each other by a connecting board, or the coils 4 (conductors 41) may be directly connected to each other by soldering, welding, etc.

[0075] The stator core 2 may be formed as a single unit. In this case, there is no need to assemble the stator core segments 2A that are divided in the circumferential direction 13, making the manufacturing of the stator 1 easier.

[0076] The tooth end face 51 and the tooth side surface 52 do not have to be flat. The boundary 53 between the tooth end face 51 and the tooth side surface 52 does not have to be a ridge. There does not have to be a clear boundary between the tooth end face 51 and the tooth side surface 52; in this case, the boundary 53 is formed by a predetermined size end of the tooth end face 51 on the tooth side surface 52 side and a predetermined size end of the tooth side surface 52 near the tooth end face 51.

[0077] The stator core 2 is not limited to one constructed by laminating multiple electromagnetic steel sheets 23.

[0078] The portion of the insulating portion 3 corresponding to the end face covering portion 63 may be part of the high thermal conductivity insulating portion 7 rather than the high strength insulating portion 6.

[0079] The side covering portion 71 may cover the entire surface of the side surface 52 of the teeth.

[0080] The base resin 31 included in the high-strength insulating section 6 and the base resin 31 included in the high-thermal-conductivity insulating section 7 do not necessarily have to be made of the same type of resin material. Furthermore, the reinforcing material 32 included in the high-strength insulating section 6 and the reinforcing material 32 included in the high-thermal-conductivity insulating section 7 do not necessarily have to be made of the same type of material, and the number and combination of materials included in each are not limited. Furthermore, the thermal conductive filler 33 included in the high-strength insulating section 6 and the thermal conductive filler 33 included in the high-thermal-conductivity insulating section 7 do not necessarily have to be made of the same type of material, and the number and combination of materials included in each are not limited.

[0081] The base resin 31 included in the high-strength insulating part 6 and the base resin 31 included in the high-thermal-conductivity insulating part 7 do not need to be integrally connected.

[0082] The flange portion 72 has an arbitrary configuration and does not have to be provided on the insulating portion 3. Also, the flange portion 72 may be provided as part of the high-strength insulating portion 6, rather than as part of the high-thermal-conductivity insulating portion 7.

[0083] (4) Summary As is clear from the embodiments and their modifications described above, the stator (1) of the first embodiment comprises a stator core (2) and an insulating portion (3) integrally formed with the stator core (2). The axial direction (91) is defined as the direction in which the axis (90), which is the rotation center of the rotor (9) facing the stator core (2), extends. The stator core (2) has a yoke (21) and a plurality of teeth (22). The plurality of teeth (22) protrude from the yoke (21) toward the rotor (9). The plurality of teeth (22) protrude in different radial directions (12) perpendicular to the axis (90). Each tooth (5) of the plurality of teeth (22) has a tooth end face (51) and a tooth side surface (52). The tooth end face (51) is located at the end in the axial direction (91). The tooth side surface (52) is located at the end in the circumferential direction (13) perpendicular to the axial direction (91) and one radial direction (12). The insulating portion (3) has a high-strength insulating portion (6) and a high-thermal-conductivity insulating portion (7). The high-strength insulating portion (6) has a boundary covering portion (61) and a wall portion (62). The boundary covering portion (61) covers the boundary portion (53) between the tooth end face (51) and the tooth side surface (52). The wall portion (62) extends from the end of the tooth end face (51) in one radial direction (12) away from each tooth (5) in the axial direction (91). The high-thermal-conductivity insulating portion (7) has a side covering portion (71) that covers the tooth side surface (52). The strength of the high-strength insulating portion (6) is greater than the strength of the high-thermal-conductivity insulating portion (7). The thermal conductivity of the high thermal conductivity insulating part (7) is greater than that of the high strength insulating part (6).

[0084] According to the first embodiment, since the stator (1) has a stator core (2) and an insulating part (3) integrally formed, it is possible to suppress the formation of a gap between the stator core (2) and the insulating part (3), making it easier to improve the strength and thermal conductivity of the stator (1). Furthermore, since the insulating part (3) has a high-strength insulating part (6) and a high-thermal-conductivity insulating part (7), it is possible to improve the thermal conductivity of the insulating part (3) while maintaining the strength of the insulating part (3).

[0085] A second embodiment can be realized by combining it with the first embodiment. In the second embodiment, the high-strength insulating part (6) and the high-thermal-conductivity insulating part (7) include, as materials, a base resin (31), a reinforcing material (32), and a thermal conductive filler (33). The base resin (31) included in the high-strength insulating part (6) and the base resin (31) included in the high-thermal-conductivity insulating part (7) are the same type of resin material. The content of the reinforcing material (32) included in the high-strength insulating part (6) is greater than the content of the reinforcing material (32) included in the high-thermal-conductivity insulating part (7). The content of the thermal conductive filler (33) included in the high-thermal-conductivity insulating part (7) is greater than the content of the thermal conductive filler (33) included in the high-strength insulating part (6).

[0086] According to the second embodiment, both strength and thermal conductivity can be adjusted simply by adjusting the content of the reinforcing material (32) and the thermal conductive filler (33), making it easy to adjust strength and thermal conductivity.

[0087] A third embodiment can be realized by combining it with the second embodiment. In the third embodiment, the base resin (31) included in the high-strength insulating part (6) and the base resin (31) included in the high-thermal-conductivity insulating part (7) are integrally connected.

[0088] According to the third embodiment, the overall strength of the insulating portion (3) can be improved.

[0089] The fourth embodiment can be realized by combining it with any of the first to third embodiments. In the fourth embodiment, the stator core (2) is constructed by laminating a plurality of electromagnetic steel sheets (23). A gap (24) formed between two of the plurality of electromagnetic steel sheets (23) is filled with a high-strength insulating portion (6) or a high-thermal-conductivity insulating portion (7) that constitutes the insulating portion (3).

[0090] According to the fourth embodiment, the stator core (2) and the insulating part (3) are firmly fixed to each other, improving the strength and thermal conductivity of the stator (1).

[0091] The fifth embodiment can be realized by combining it with any of the first to fourth embodiments. In the fifth embodiment, the opposing surfaces of the insulating portion (3) and the stator core (2) that face each other are joined together.

[0092] According to the fifth embodiment, no gap is formed between the insulating part (3) and the stator core (2), and the strength and thermal conductivity of the stator (1) are improved.

[0093] The sixth embodiment can be realized by combining it with any of the first to fifth embodiments. In the sixth embodiment, the motor (8) is an inner rotor type, comprising a stator (1) of any of the first to fifth embodiments and a rotor (9) disposed on the inner circumference of the stator (1).

[0094] According to the sixth embodiment, in an inner rotor type motor (8), the stator (1) has a stator core (2) and an insulating part (3) integrally formed, which suppresses the formation of a gap between the stator core (2) and the insulating part (3), making it easier to improve the strength and thermal conductivity of the stator (1). Furthermore, since the insulating part (3) has a high-strength insulating part (6) and a high-thermal-conductivity insulating part (7), it is possible to improve the thermal conductivity of the insulating part (3) while maintaining the strength of the insulating part (3).

[0095] The seventh embodiment can be realized by combining it with any of the first to fifth embodiments. In the seventh embodiment, the motor (8) comprises a stator (1) of any of the first to fifth embodiments and a rotor (9). The stator core (2) of the stator (1) is divided in the circumferential direction (13).

[0096] According to the seventh embodiment, the coil (4) can be attached to each stator core segment (2A) which is divided in the circumferential direction (13), making it easier to manufacture the stator (1).

[0097] The eighth embodiment can be realized by combining it with any of the first to fifth embodiments. In the eighth embodiment, the motor (8) comprises a stator (1) of any of the first to fifth embodiments and a rotor (9). The stator core (2) of the stator (1) is formed integrally.

[0098] According to the eighth aspect, there is no need to assemble the stator core segments (2A) which are divided in the circumferential direction (13), making it easier to manufacture the stator (1).

[0099] The stator and motor of this disclosure can improve the thermal conductivity of the insulating portion while maintaining its strength. Therefore, the strength and thermal conductivity of the insulating portion and teeth can be improved, resulting in improved motor strength and heat dissipation. Thus, the stator and motor of this disclosure are industrially useful.

[0100] 1 Stator 1A Stator segment 12 Radial direction 13 Circumferential direction 2 Stator core 2A Stator core segment 21 Yoke 21A Yoke segment 23 Electromagnetic steel sheet 24 Gap 3 Insulation part 31 Base resin 32 Reinforcement material 33 Thermal conductive filler 5 Teeth 51 Teeth end face 52 Teeth side surface 53 Boundary part 6 High-strength insulation part 61 Boundary cover part 62 Wall part 621 Inner wall part 622 Outer wall part 7 High thermal conductivity insulation part 71 Side cover part 8 Motor 9 Rotor 90 Axial center 91 Axial direction

Claims

1. The rotor comprises a stator core and an insulating portion formed integrally with the stator core, wherein the direction in which the axis, which is the rotation center of the rotor facing the stator core, extends is defined as the axial direction, the stator core has a yoke and a plurality of teeth projecting from the yoke toward the rotor, the plurality of teeth projecting in different radial directions perpendicular to the axis, each of the plurality of teeth has a tooth end face located at the end in the axial direction and a tooth side surface located at the end in the circumferential direction perpendicular to the axial direction and the one radial direction, the insulating portion has a high-strength insulating portion and a high-thermal-conductivity insulating portion, the high-strength insulating portion has a boundary covering portion that covers the boundary between the tooth end face and the tooth side surface and a wall portion that extends from the end of the tooth end face in the one radial direction toward each of the teeth in the axial direction, and the high-thermal-conductivity insulating portion has a side covering portion that covers the tooth side surface. A stator in which the strength of the high-strength insulating portion is greater than the strength of the high-thermal-conductivity insulating portion, and the thermal conductivity of the high-thermal-conductivity insulating portion is greater than the thermal conductivity of the high-strength insulating portion.

2. The stator according to claim 1, wherein the high-strength insulating portion and the high-thermal-conductivity insulating portion each include, as materials, a base resin, a reinforcing material, and a thermal conductive filler, the base resin included in the high-strength insulating portion and the base resin included in the high-thermal-conductivity insulating portion are of the same type of resin material, the content of the reinforcing material included in the high-strength insulating portion is greater than the content of the reinforcing material included in the high-thermal-conductivity insulating portion, and the content of the thermal conductive filler included in the high-thermal-conductivity insulating portion is greater than the content of the thermal conductive filler included in the high-strength insulating portion.

3. The stator according to claim 2, wherein the base resin included in the high-strength insulating portion and the base resin included in the high-thermal-conductivity insulating portion are integrally connected.

4. The stator according to claim 1, wherein the stator core is constructed by laminating a plurality of electromagnetic steel sheets, and the gaps formed between the plurality of electromagnetic steel sheets are filled with the high-strength insulating portion or the high-thermal-conductivity insulating portion that constitutes the insulating portion.

5. The stator according to claim 1, wherein the opposing surfaces of the insulating portion and the stator core that face each other are joined together.

6. An inner-rotor type motor comprising a stator as described in claim 1 and a rotor disposed on the inner circumference of the stator.

7. A motor comprising a stator as described in claim 1 and a rotor, wherein the stator core of the stator is divided in the circumferential direction.

8. A motor comprising the stator described in claim 1 and the rotor, wherein the stator core of the stator is integrally formed.

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