Motor and method for manufacturing coil
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
- Filing Date
- 2025-10-03
- Publication Date
- 2026-07-02
Smart Images
Figure JP2025035274_02072026_PF_FP_ABST
Abstract
Description
Method for manufacturing motor and coil
[0001] The present disclosure generally relates to a method for manufacturing a motor and a coil, and more particularly to a method for manufacturing a motor including a coil and a coil.
[0002] Patent Document 1 discloses a stator used for constructing a rotating electric machine such as an electric motor or a generator. The stator includes a stator core and three-phase coil wires of U-phase, V-phase, and W-phase wound around the stator core in a distributed winding manner. The coil wire has a pipe material constituting the outer skin and a heat storage material which is a low melting point metal filled inside the pipe material.
[0003] Japanese Patent Laid-Open No. 2020-89232
[0004] By the way, in the coil wire (coil) used for an electric motor or the like as disclosed in Patent Document 1, it is desired to suppress temperature rise.
[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a method for manufacturing a motor and a coil capable of suppressing temperature rise.
[0006] A motor according to one aspect of the present disclosure includes a magnetic core and a coil. The coil is wound in multiple layers in three or more layers in a layer direction intersecting the winding axis direction of the coil with respect to the magnetic core. The coil has a first portion and a second portion arranged side by side in the wire length direction of the coil. The material of the first portion of the coil contains a predetermined metal material which is copper or aluminum. The material of the second portion of the coil contains the predetermined metal material and vanadium oxide. The content rate of the predetermined metal material in the first portion is higher than the content rate of the predetermined metal material in the second portion. The second portion is arranged in at least one of the coil end portion of the coil and the internal region of the coil.
[0007] A method for manufacturing a coil according to another aspect of the present disclosure forms the coil of the motor by additive manufacturing.
[0008] According to the present disclosure, it is possible to suppress the temperature rise of the coil, and thus the motor using the coil.
[0009] Figure 1 is a schematic diagram showing the configuration of a motor according to the embodiment. Figure 2 is a schematic cross-sectional view showing the main part of the motor according to the embodiment. Figure 3 is another schematic cross-sectional view showing the main part of the motor according to the embodiment. Figure 4 is a schematic cross-sectional view of a coil included in the motor according to the embodiment. Figure 5 is a graph showing the relationship between the volume fraction and latent heat of vanadium dioxide, which is the material of the coil included in the motor according to the embodiment, and the relationship between the volume fraction and thermal conductivity. Figure 6 is a schematic cross-sectional view of a coil included in a motor according to Modification 1.
[0010] Preferred embodiments of this disclosure will be described in detail below with reference to the drawings. Common elements in the embodiments described below are denoted by the same reference numerals, and redundant descriptions of common elements may be omitted. Note that the following embodiments and their variations are only a part of the various embodiments of this disclosure. Furthermore, the following embodiments and their variations can be modified in various ways depending on the design, etc., as long as the objectives of this disclosure are achieved. It is also possible to combine the configurations of the embodiments and their variations as appropriate.
[0011] The figures described in this disclosure are schematic diagrams, and the ratios of the size and thickness of each component in each figure do not necessarily reflect the actual dimensional ratios. Furthermore, the arrows indicating directions in the drawings are examples only and are not intended to specify the direction in which the motor should be used. Also, the arrows indicating directions in the drawings are for illustrative purposes only and do not represent actual dimensions.
[0012] (1) Overview First, an overview of the motor 1 according to this embodiment will be described with reference to Figures 1 to 3.
[0013] Figure 1 is a schematic diagram showing the configuration of the motor 1 according to this embodiment. As shown in Figure 1, the motor 1, which is an AC (alternating current) motor of this embodiment, comprises a plurality of teeth 31 (magnetic cores) (nine in the example of Figure 1) and a plurality of coils 4 (nine in the example of Figure 1). There is a one-to-one correspondence between the plurality of teeth 31 and the plurality of coils 4.
[0014] Figure 2 is a schematic cross-sectional view showing the main parts of the motor 1 according to this embodiment. As shown in Figure 2, the coil 4 is wound in three or more layers on a magnetic core in a layer direction D2 that intersects the winding axis direction D1 of the coil 4. The coil 4 has a first portion 41 and a second portion 42 that are aligned in the direction of the length of the coil 4.
[0015] The material of the first portion 41 of the coil 4 includes a predetermined metal material, which is copper or aluminum. The material of the second portion 42 of the coil 4 includes the predetermined metal material and vanadium oxide. The content of the predetermined metal material in the first portion 41 is higher than the content of the predetermined metal material in the second portion 42. In this embodiment, the predetermined metal material is copper. However, the predetermined metal material may be aluminum.
[0016] In Figure 2, the area with darker hatching (more hatching lines) is the second part 42, and the area with lighter hatching (fewer hatching lines) is the first part 41.
[0017] Figure 3 is another schematic cross-sectional view showing the main part of the motor 1 according to this embodiment. In Figure 3, the part with dark dot hatching is the second part 42, and the part with light dot hatching is the first part 41. As shown in Figures 2 and 3, the second part 42 is located in at least one of the coil end portion of the coil 4 and the internal region A0 (see Figure 2) of the coil 4.
[0018] Here, vanadium oxide is vanadium dioxide. Vanadium dioxide undergoes a crystalline phase change around a predetermined temperature (for example, 60°C to 70°C). Latent heat is generated in vanadium dioxide due to the crystalline phase change. As a result, when the motor 1 is operating and the temperature of coil 4 reaches around the predetermined temperature, the vanadium dioxide undergoes a crystalline phase change and latent heat is generated. The vanadium dioxide absorbs the Joule heat generated in coil 4, thereby suppressing the temperature rise of coil 4.
[0019] Furthermore, the second part 42 of this embodiment is positioned in areas of the coil 4 where temperature rise is particularly likely to occur, such as the coil end portion of the coil 4 and the internal region A0 of the coil 4. This makes it possible to more effectively suppress the temperature rise of the coil 4.
[0020] (2) Details The detailed configuration of the motor 1 according to this embodiment will be described below with reference to Figures 1 to 4. Figure 4 is a schematic cross-sectional view of the coil 4 provided in the motor 1.
[0021] (2.1) As shown in the motor configuration diagram 1, the motor 1 comprises a stator 2, a rotor 5, and a housing 10. The housing 10 houses the stator 2 and the rotor 5.
[0022] (2.2) Rotor Configuration The rotor 5 has a rotor core 51, a plurality of permanent magnets 52 (eight in the example of Figure 1), and a motor shaft 53.
[0023] The rotor core 51 is located inside the stator 2. The rotor core 51 has a cylindrical shape centered on the motor shaft 53. The rotor core 51 is made of, for example, iron. However, the rotor core 51 may be made of silicon steel, permalloy, or ferrite, etc. The rotor core 51 holds a plurality of permanent magnets 52.
[0024] Multiple permanent magnets 52 are arranged on the outer circumference of the rotor core 51. The multiple permanent magnets 52 are arranged so that north poles and south poles alternate in the circumferential direction of the rotor core 51. The multiple permanent magnets 52 are permanent magnets such as neodymium magnets.
[0025] The motor shaft 53 is fixed to the inner circumference of the rotor core 51. The shape of the motor shaft 53 is cylindrical.
[0026] The interaction between the magnetic fields generated by the multiple permanent magnets 52 and the magnetic fields generated by the current flowing through the multiple coils 4 of the stator 2 causes the rotor core 51 and the motor shaft 53 to rotate around the rotation axis Ax1.
[0027] (2.3) Stator Configuration The overall shape of the stator 2 is cylindrical with the motor shaft 53 at its center. The stator 2 has a stator core 3 (magnetic core) and a plurality of coils 4 (nine in the example in Figure 1).
[0028] The stator core 3 is a magnetic core made of, for example, silicon steel. The stator core 3 has an outer circumference 32 and a plurality of teeth 31 (nine in the example in Figure 1).
[0029] The outer circumference 32 has a cylindrical shape centered on the motor shaft 53.
[0030] Each of the multiple teeth 31 corresponds one-to-one with one of the multiple coils 4. The multiple teeth 31 are arranged at equal intervals (i.e., equal angular intervals) along the circumferential direction of the outer circumference 32. The multiple teeth 31 protrude from the inner circumferential surface of the outer circumference 32 toward the motor shaft 53 along the radial direction of the motor shaft 53. Each of the multiple teeth 31 is the winding axis of the corresponding coil 4 among the multiple coils 4. In other words, the winding axis direction D1 of the coil 4 (see Figure 2) is along the radial direction of the motor shaft 53.
[0031] Multiple coils 4 are arranged at equal intervals along the circumferential direction of the motor shaft 53. As shown in Figure 2, the coils 4 in this embodiment are made of round wire. Figure 2 is a schematic cross-sectional view obtained by cutting the coils 4 through a virtual plane. Note that the normal direction of the virtual plane in this embodiment is along the axial direction of the motor shaft 53.
[0032] The coil 4 is wound multiple times around the corresponding teeth 31 in both the winding axis direction D1 and the layer direction D2. More specifically, the coil 4 is wound three or more times around the teeth 31 along the winding axis direction D1 of the coil 4. Furthermore, the coil 4 is multi-layered, with three or more layers when viewed from the winding axis direction D1 of the coil 4. The coil 4 is wound around the teeth 31 such that it is layered in the layer direction D2, which is perpendicular to the winding axis direction D1 when viewed from the winding axis direction D1. Note that in this embodiment, "multi-layered, with three or more layers" means that it is sufficient if there is at least one location with three or more layers, and it is not necessary for all parts of the coil 4 to have three or more layers. In the example in Figure 2, in the first layer, which is closest to the teeth 31 in the layer direction D2, the coil 4 is wound six times along the winding axis direction D1. In the second layer, the coil 4 is wound six times along the winding axis direction D1. In the third layer, the coil 4 is wound five times along the winding axis direction D1. Furthermore, in the fourth layer, which is furthest from the teeth 31 in the layer direction D2, the coil 4 is wound twice along the winding axis direction D1.
[0033] Furthermore, the term "orthogonal (perpendicular)" as used in this disclosure includes not only a state where the angle between two objects is exactly 90 degrees, but also a state where the two objects intersect within a certain range of difference. In other words, the angle between two orthogonal objects falls within a certain range of difference from 90 degrees (for example, 5 degrees or less). That is, "orthogonal" as used in this disclosure includes cases where the angle between two objects is between 85 degrees and 95 degrees. Similarly, the term "parallel" as used in this disclosure includes not only a state where two objects do not intersect exactly, but also a state where two objects are aligned within a certain range of difference. For example, "parallel" as used in this disclosure includes cases where the inclination of one object relative to the other is 5 degrees or less. That is, "parallel" as used in this disclosure includes cases where the angle between one object and the other is between -5 degrees and 5 degrees.
[0034] The adjacent portions of the coil 4 (the multiple cross-sections of the coil 4 in Figure 2) are electrically insulated by an insulating member 7 made of polyurethane or the like. In Figure 2, the insulating member 7 is shown with dodge hatching.
[0035] As shown in Figures 3 and 4, the coil 4 of this embodiment has a first portion 41, a second portion 42, and an insulating coating 43. The first portion 41 and the second portion 42 are aligned in the length direction of the coil 4. In this embodiment, the second portion 42 is located in both the coil end portion of the coil 4 and the internal region A0 of the coil 4. However, the second portion 42 only needs to be located in at least one of the coil end portion of the coil 4 and the internal region A0 of the coil 4.
[0036] Here, the "coil end portion of coil 4" refers to the portion of coil 4 that is outside the first end 311 of teeth 31 (upper in Figure 3) and outside the second end 312 of teeth 31 (lower in Figure 3), as shown in Figure 3, in a plan view from the winding axis direction D1. In this embodiment, the "coil end portion of coil 4" refers to the portion of coil 4 that is outside the first end 311 of teeth 31 and outside the second end 312 of teeth 31, in the axial direction of the motor shaft 53. In the example in Figure 3, the portion of coil 4 that is located within region A1 and the portion located within region A2 are the coil end portions. In other words, the portion of coil 4 that is located within region A1 and the portion located within region A2 are the second portion 42.
[0037] Furthermore, "internal region A0 of coil 4" is a part of coil 4, and is the region surrounded by other parts of coil 4 that are different from that part in the winding axis direction D1 and the layer direction D2. In other words, "internal region A0 of coil 4" is the region surrounded by the end parts in the winding axis direction D1 and the layer direction D2. To put it another way, "internal region A0 of coil 4" is the region excluding the end parts in the winding axis direction D1 and the layer direction D2. In the example in Figure 2, the second turn of the second layer (second from the bottom in Figure 2), the third turn, the fourth turn, and the fifth turn of coil 4, and the fourth turn of the third layer (fourth from the bottom in Figure 2) are located in internal region A0 of coil 4.
[0038] The material of the first portion 41 of the coil 4 includes a predetermined metallic material which is copper or aluminum. In the present embodiment, the predetermined metal is copper, and the first portion 41 is mainly formed of copper. The copper content rate of the first portion 41 is approximately 100%.
[0039] As described above, in the present embodiment, the second portion 42 is disposed in both the coil end portion of the coil 4 and the internal region A0 of the coil 4. The material of the second portion 42 of the coil 4 includes a predetermined metallic material and vanadium oxide. In the present embodiment, the second portion 42 is mainly formed of copper as the predetermined metallic material and vanadium dioxide. The copper content rate and the vanadium dioxide content rate of the second portion 42 are approximately 50% each.
[0040] That is, in the present embodiment, the content rate of the predetermined metallic material (copper) of the first portion 41 is higher than the content rate of the predetermined metallic material (copper) of the second portion 42.
[0041] FIG. 4 is a schematic cross-sectional view showing a cross section of the second portion 42 of the coil 4. As shown in FIG. 4, the second portion 42 of the present embodiment has a plurality (five layers in the example of FIG. 4) of first layer portions 401 and a plurality (four layers in the example of FIG. 4) of second layer portions 402.
[0042] The plurality of first layer portions 401 and the plurality of second layer portions 402 are arranged so as to be alternately arranged in parallel with the wire length direction. That is, the plurality of first layer portions 401 and the plurality of second layer portions 402 are arranged so as to be alternately arranged in a direction orthogonal to the wire length direction. Also, the plurality of first layer portions 401 and the plurality of second layer portions 402 are in parallel with each other in the current path. Also, in the cross section of the second portion 42, the shapes of the plurality of first layer portions 401 and the shapes of the plurality of second layer portions 402 are strip-shaped.
[0043] The material of the plurality of first layer portions 401 is a predetermined metallic material. That is, the plurality of first layer portions 401 of the present embodiment are mainly formed of copper.
[0044] The material of the plurality of second layer portions 402 is vanadium dioxide. That is, the plurality of second layer portions 402 of the present embodiment are mainly formed of vanadium dioxide.
[0045] In this embodiment, the coil 4 is formed by additive manufacturing (AM). In the second portion 42, the portion formed of copper (a predetermined metal material) (first layered portion 401) and the portion formed of vanadium dioxide (second layered portion 402) are layered, making it easy to form the second portion 42 by additive manufacturing.
[0046] Figure 5 is a graph showing the relationship between the volume fraction and latent heat of vanadium dioxide, which is the material of the coil 4 in the motor 1 according to the embodiment, and the relationship between the volume fraction and thermal conductivity. Graph G1 in Figure 5 shows the relationship between the volume fraction and latent heat of vanadium dioxide when copper and vanadium dioxide are combined. Graph G2 in Figure 5 shows the relationship between the volume fraction and thermal conductivity of vanadium dioxide when copper and vanadium dioxide are combined. The horizontal axis of graphs G1 and G2 represents the volume fraction of vanadium dioxide when copper and vanadium dioxide are combined. In the following explanation, the volume fraction of vanadium dioxide when copper and vanadium dioxide are combined may be simply referred to as the "volume fraction of vanadium dioxide".
[0047] As shown in graphs G1 and G2, the magnitude of latent heat and thermal conductivity changes by changing the volume fraction of vanadium dioxide. Note that for many metals, thermal conductivity and electrical conductivity are proportional. In other words, the magnitude of electrical conductivity changes by changing the volume fraction of vanadium dioxide. That is, by changing the amount of vanadium dioxide contained in the second part 42 of the coil 4, the magnitude of latent heat and the magnitude of electrical conductivity can be adjusted when manufacturing the coil 4. For example, by changing the ratio of multiple first layered parts 401 mainly made of copper and multiple second layered parts 402 mainly made of vanadium dioxide, the magnitude of latent heat and the magnitude of electrical conductivity can be adjusted when manufacturing the coil 4.
[0048] When motor 1 is in operation, the temperature of coil 4 rises due to Joule heating, and when vanadium dioxide reaches a predetermined temperature, the vanadium dioxide undergoes a crystalline phase change and latent heat is released. The vanadium dioxide absorbs the Joule heat generated in coil 4, thereby suppressing the temperature rise of coil 4.
[0049] Also, the heat storage amount of the second portion 42 of the present embodiment is larger than the assumed Joule heat. The assumed Joule heat is the Joule heat generated in the second portion 42 in one second assumed when the second portion 42 has the same configuration as the first portion 41 and the rated current in the motor 1 flows through the coil 4. In the present embodiment, the assumed Joule heat is the Joule heat generated in the second portion 42 in one second assumed when the second portion 42 is mainly formed of copper and the rated current flows through the coil 4. Here, the rated current in the motor 1 is the current value of the current flowing through the coil 4 defined in the catalog or specification of the motor 1. Since the heat storage amount of the second portion 42 is larger than the assumed Joule heat, further suppression of the temperature rise of the coil 4 can be achieved.
[0050] (3) Coil manufacturing method Next, a method for manufacturing the coil 4 used in the motor 1 which is an AC motor of the present embodiment will be described.
[0051] In the manufacturing method of the coil 4 of the present embodiment, the coil 4 is formed by additive manufacturing (AM).
[0052] More specifically, in the method for manufacturing the coil 4 of this embodiment, the coil 4 is formed by additive manufacturing so that it is wound in three or more layers on the teeth 31 (magnetic core) in the layer direction D2 of the coil 4, which intersects the winding axis direction D1 of the coil 4. In addition, in the method for manufacturing the coil 4 of this embodiment, the coil 4 is formed by additive manufacturing so that it has a first portion 41 and a second portion 42 that are aligned in the length direction of the coil 4. Here, in the method for manufacturing the coil 4 of this embodiment, the first portion 41 is formed by additive manufacturing using a predetermined metal material, which is copper or aluminum, and the second portion 42 is formed using the predetermined metal material and vanadium oxide. Furthermore, in the method for manufacturing the coil 4 of this embodiment, the first portion 41 and the second portion 42 are formed by additive manufacturing such that the content of the predetermined metal material in the first portion 41 is higher than the content of the predetermined metal material in the second portion 42. Furthermore, in the manufacturing method of the coil 4 of this embodiment, the second portion 42 is formed by additive manufacturing such that the second portion 42 is positioned at least one of the coil end portion of the coil 4 and the internal region A0 of the coil 4.
[0053] This makes it possible to manufacture a coil 4 that can suppress temperature rise relatively easily.
[0054] (4) Modifications Below are some modifications of the above embodiment.
[0055] (4.1) Modification 1 Figure 6 is a schematic cross-sectional view of the coil 4 provided in the motor 1 according to Modification 1. In the above embodiment, the case in which the coil 4 is a round wire was illustrated. However, the coil 4 is not limited to a round wire. For example, as shown in Figure 6, the coil 4 of Modification 1 is a rectangular wire. That is, in the coil 4 of Modification 1, the first part 41 and the second part 42 of the coil 4 are rectangular in shape.
[0056] This allows for a larger occupancy rate (or packing ratio) of the coil 4 within the motor 1. In the motor 1 of Modification 1, increasing the packing ratio of the coil 4 reduces the losses of the coil 4 and increases the heat capacity of the coil 4, thereby further suppressing the temperature rise of the coil 4.
[0057] Note that the coil 4 in Figure 6 is a rectangular wire with a rectangular cross-section. However, the coil 4 may be a rectangular wire with a cross-section of other polygonal shapes, such as a hexagon. Also, the coil 4 may be a flat rectangular wire.
[0058] (4.2) Other Modifications In the above embodiment, the case in which motor 1 is an inner rotor type motor was illustrated, but motor 1 may be an outer rotor type motor. Also, in the above embodiment, the case in which motor 1 is a servo motor was illustrated, but motor 1 may be a motor other than a servo motor.
[0059] (Aspects) As is clear from the embodiments and modifications described above, the motor (1) according to the first aspect comprises a magnetic core (teeth 31) and a coil (4). The coil (4) is multi-layer wound in three or more layers on the magnetic core in a layer direction (D2) intersecting the winding axis direction (D1) of the coil (4). The coil (4) has a first portion (41) and a second portion (42) aligned in the length direction of the coil (4). The material of the first portion (41) of the coil (4) includes a predetermined metallic material, which is copper or aluminum. The material of the second portion (42) of the coil (4) includes the predetermined metallic material and vanadium oxide. The content of the predetermined metallic material in the first portion (41) is higher than the content of the predetermined metallic material in the second portion (42). The second portion (42) is located in at least one of the coil end portion of the coil (4) and the internal region (A0) of the coil (4).
[0060] According to this embodiment, it is possible to suppress the temperature rise of the coil (4).
[0061] In the motor (1) according to the second embodiment, the amount of heat stored in the second part (42) is greater than the assumed Joule heat, as in the first embodiment. The assumed Joule heat is the amount of Joule heat that is assumed to be generated in the second part (42) per second, assuming that the second part (42) has the same configuration as the first part (41) and that the rated current in the motor (1) flows through the coil (4).
[0062] According to this embodiment, the temperature rise of the coil (4) can be further suppressed.
[0063] In the motor (1) according to the third embodiment, in the first or second embodiment, the second portion (42) has a plurality of first layered portions (401) and a plurality of second layered portions (402). The plurality of first layered portions (401) and the plurality of second layered portions (402) are arranged alternately in parallel to the wire length direction. The material of the plurality of first layered portions (401) is a predetermined metallic material. The material of the plurality of second layered portions (402) is vanadium oxide.
[0064] According to this embodiment, the second part (42) is easily formed by additive manufacturing.
[0065] Configurations other than those in the first embodiment are not essential to the motor (1) and can be omitted as appropriate.
[0066] The method for manufacturing the coil (4) according to the fourth embodiment involves forming the coil (4) of the motor (1) according to any of the first to third embodiments by additive manufacturing.
[0067] According to this embodiment, a coil (4) that can suppress temperature rise can be manufactured relatively easily.
[0068] The motor of this disclosure can suppress the temperature rise of the coil and, consequently, the motor equipped with said coil. Furthermore, the method for manufacturing the coil of this disclosure allows for the relatively easy manufacture of a coil that can suppress temperature rise. Thus, the motor and the method for manufacturing the coil of this disclosure are industrially useful.
[0069] 1 Motor 31 Teeth (magnetic core) 4 Coil 401 First layer 402 Second layer 41 First part 42 Second part D1 Winding axis direction D2 Layer direction
Claims
1. A motor comprising: a magnetic core; and a coil wound in three or more layers in a layer direction intersecting the winding axis direction with respect to the magnetic core, and having a first portion and a second portion aligned in the length direction of the wire, wherein the material of the first portion of the coil includes a predetermined metal material which is copper or aluminum; the material of the second portion of the coil includes the predetermined metal material and vanadium oxide; the content of the predetermined metal material in the first portion is higher than the content of the predetermined metal material in the second portion; and the second portion is located in at least one of the coil end portion and the internal region of the coil.
2. The amount of heat stored in the second part is greater than the assumed Joule heat, and the assumed Joule heat is the Joule heat that is assumed to be generated in the second part over one second, assuming that the second part has the same configuration as the first part and that the rated current of the motor flows through the coil. The motor according to claim 1.
3. The motor according to claim 1 or 2, wherein the second portion comprises a plurality of first layered portions and a plurality of second layered portions, the plurality of first layered portions and the plurality of second layered portions are arranged alternately parallel to the linear length direction, the material of the plurality of first layered portions is the predetermined metal material, and the material of the plurality of second layered portions is vanadium oxide.
4. A method for manufacturing a coil, wherein the coil of the motor described in claim 1 or 2 is formed by additive manufacturing.