Motor

Abstract

A purpose of the present invention is to efficiently diffuse heat that is generated in the coils of a motor without machining the coils. A stator (3) includes a stator yoke (32), teeth (33), coils (34), a first heat conduction member (35), a second heat conduction member (36), and an insulating member (37). The coils (34) are wound around the teeth (33) and have a plurality of gaps that separate adjacent portions of conductive wires (34a). The first heat conduction member (35) is formed along the side surfaces of the stator yoke (32) and the teeth (33). The second heat conduction member (36) protrudes from the first heat conduction member (35) so as to be provided in at least one of the gaps. The insulating member (37) is filled between the coils (34), the first heat conduction member (35), and the second heat conduction member (36). The first heat conduction member (35), the second heat conduction member (36), and the insulating member (37) have electrical insulation properties. The first heat conduction member (35) and the second heat conduction member (36) have higher thermal conductivity than that of the insulating member (37).

Description

Motor

[0001] The present disclosure generally relates to a motor, and more particularly to a motor having wound conducting wires.

[0002] In Patent Document 1, there is described a winding component and its heat dissipation structure capable of efficiently discharging the heat generated by a coil to the outside, reducing the product temperature, and thus enabling miniaturization and weight reduction.

[0003] In the winding component in Patent Document 1, in a laminated inductor having a coil formed by alternately laminating a metal plate and an insulating plate and a core that surrounds the coil to form a closed magnetic path, a heat dissipation extension portion that extends outside the coil and is thermally connected to a housing having a heat dissipation function is formed on the metal plate located in the middle portion in the lamination direction. Further, in the winding component in Patent Document 1, on the insulating plate adjacent to the metal plate on which the heat dissipation extension portion is formed, an insulating extension portion that is interposed between the heat dissipation extension portion and the housing when thermally connecting the heat dissipation extension portion to the housing and insulates between the heat dissipation extension portion and the housing is formed along the heat dissipation extension portion.

[0004] Japanese Patent Application Laid-Open No. 2015-198181

[0005] In Patent Document 1, by providing an extension portion on the coil and transferring the generated heat to a housing having a heat dissipation function, the temperature can be reduced. However, since it is necessary to perform processing on the coil to provide the extension portion, it is difficult to efficiently diffuse the heat generated in the coil without performing processing on the coil.

[0006] In view of the above problems, the present disclosure aims to provide a motor capable of efficiently diffusing the heat generated in the coil without performing processing on the coil.

[0007] A motor according to one aspect of the present disclosure comprises a rotor and a stator. The rotor includes a rotor yoke and permanent magnets. The rotor yoke is cylindrical and has a rotation axis with its axis as the center of rotation. The permanent magnets are arranged on the side surface of the rotor yoke. The stator includes a stator yoke, teeth, a coil, a first heat conduction member, a second heat conduction member, and an insulating member. The stator yoke is hollow cylindrical with its outer surface concentric with the rotor. The teeth project from the circumferential position of the rotor yoke toward the rotation axis on the inner surface of the stator yoke. The coil has a wire wound around the teeth and has a plurality of gaps that separate adjacent portions of the wire. The first heat conduction member is molded along the inner surface of the stator yoke and the side surface of the teeth. The second heat conduction member projects from the first heat conduction member so as to be provided in at least one of the plurality of gaps. The insulating member is filled between the coil, the first heat conduction member, and the second heat conduction member, respectively. The first heat conduction member, the second heat conduction member, and the insulating member all possess electrical insulating properties, and the first heat conduction member and the second heat conduction member have higher thermal conductivity than the insulating member.

[0008] According to one aspect of the present disclosure, the motor can efficiently dissipate the heat generated in the coil without any processing of the coil.

[0009] Figure 1 is a perspective view of the rotor of the motor according to this embodiment. Figure 2 is a top view of the motor according to this embodiment. Figure 3 is a schematic cross-sectional view showing the main parts of the motor according to this embodiment. Figure 4 is a schematic cross-sectional view showing the main parts of the motor according to Modification 2. Figure 5 is a schematic cross-sectional view showing the main parts of the motor according to Modification 3. Figure 6 is a schematic cross-sectional view showing the main parts of the motor according to Modification 4. Figure 7 is a schematic cross-sectional view showing the main parts of the motor according to Modification 5. Figure 8 is a schematic cross-sectional view showing the main parts of the motor according to Modification 6. Figure 9 is a schematic cross-sectional view showing the main parts of the motor according to Modification 7.

[0010] The embodiments and modifications described below are merely examples of the present disclosure, and the present disclosure is not limited to these embodiments and modifications. Various modifications are possible, such as design changes, without departing from the technical concept of the present disclosure, even if they are not described below.

[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 1 is used. Also, the arrows indicating directions in the drawings are for illustrative purposes only and do not represent actual dimensions.

[0012] (Embodiment) Hereinafter, the motor 1 according to this embodiment will be described with reference to Figures 1 to 3.

[0013] (1) Schematic Figure 1 is a perspective view of the rotor 2 of the motor 1 according to this embodiment. Figure 2 is a top view of the motor 1 according to this embodiment. Figure 3 is a schematic cross-sectional view showing the main parts of the motor 1 according to this embodiment. As shown in Figure 1, the motor 1 according to this embodiment comprises a rotor 2 and a stator 3. The rotor 2 includes a cylindrical rotor yoke 22 and permanent magnets 23. The rotor yoke 22 has a rotation axis 21 with axis Ax1 as the rotation center. The permanent magnets 23 are arranged on the side surface of the rotor yoke 22. As shown in Figure 3, the stator 3 includes a hollow cylindrical stator yoke 32, teeth 33, coils 34, a first heat conductive member 35, a second heat conductive member 36, and an insulating member 37. The outer circumferential surface of the stator yoke 32 is arranged concentrically with the rotor 2. The teeth 33 protrude toward the rotation axis 21 from multiple positions in the circumferential direction of the rotor yoke 22 on the inner surface of the stator yoke 32. The coil 34 has a conductor 34a wound around teeth 33, and has a plurality of gaps between adjacent portions separated by a first interval D3 along a first direction D1 which is the winding axis direction of the conductor 34a. The first heat conductive member 35 is formed along the inner surface of the stator yoke 32 and the side surface of teeth 33. The second heat conductive member 36 protrudes from the first heat conductive member 35 so as to be provided in at least one of the plurality of gaps. The insulating member 37 is filled between the coil 34, the first heat conductive member 35, and the second heat conductive member 36. The first heat conductive member 35, the second heat conductive member 36, and the insulating member 37 are electrically insulating. The first heat conductive member 35 and the second heat conductive member 36 have a higher thermal conductivity than the insulating member 37.

[0014] In this configuration, the first heat conduction member 35 and the second heat conduction member 36 are formed as heat dissipation paths that have an electrical insulation function for the coil 34. In other words, it is possible to perform electrical insulation and heat dissipation simultaneously without processing the coil 34. That is, the heat generated in the coil 34 can be efficiently diffused without processing the coil 34.

[0015] (2) The motor 1 is, for example, an inner rotor type servo motor. During high-load operation such as servo lock, the output of the motor 1 is, for example, about 350% of the rated output. The motor 1 transmits rotational force to industrial machinery such as conveying machines or machine tools, or to loads such as robots, and drives the loads. Power is supplied to the motor 1 from, for example, a control device.

[0016] As shown in Figure 1, the motor 1 comprises a rotor 2, a stator 3, and a motor housing 4.

[0017] The motor housing 4 houses the rotor 2 and the stator 3. The motor housing 4 has the function of protecting the rotor 2 and the stator 3.

[0018] (2.1) The rotor 2 comprises a rotor yoke 22 and permanent magnets 23. Here, the rotor 2 comprises a plurality of permanent magnets 23.

[0019] The rotor yoke 22 is located inside the stator 3. The rotor yoke 22 has a hollow cylindrical shape centered on the axis Ax1. The rotor yoke 22 is made of, for example, iron. However, the rotor yoke 22 may also be made of silicon steel, permalloy, or ferrite. A circular hole is provided in the center of the rotor yoke 22. The rotating shaft 21 is inserted into the hole in the rotor yoke 22. The rotating shaft 21 is fixed to the inner circumference of the rotor yoke 22. The rotating shaft 21 has a cylindrical shape. The rotor yoke 22 holds a plurality of permanent magnets 23.

[0020] The multiple permanent magnets 23 are, for example, neodymium magnets. As shown in Figure 2, the multiple permanent magnets 23 are mounted on the outer circumference of the rotor yoke 22 at equal intervals, with the north poles and south poles alternating. The multiple permanent magnets 23 face the multiple teeth 33 and the multiple tooth protrusions 33a, which will be described later, with air gaps between them.

[0021] Due to the interaction of the magnetic fields generated by the multiple permanent magnets 23 and the magnetic fields generated by the current flowing through the multiple coils 34 included in the stator 3, the rotor yoke 22 and the rotation shaft 21 rotate integrally around the axis Ax1.

[0022] (2.2) As shown in Figure 3, the stator 3 includes a stator yoke 32, teeth 33, a coil 34, a first heat conductive member 35, a second heat conductive member 36, and an insulating member 37. In this embodiment, the stator 3 further includes a third heat conductive member 38.

[0023] Here, as shown in Figure 2, the stator 3 includes a plurality of teeth 33 (9 in the illustrated example). As shown in Figure 2, the stator 3 includes a plurality of coils 34 (9 in the illustrated example) corresponding to each of the plurality of teeth 33. For each tooth 33, the stator 3 includes a plurality of first heat conductive members 35 (2 in the illustrated example), as shown in Figure 3. That is, the stator 3 includes a number of first heat conductive members 35 obtained by multiplying the number of teeth 33 by the number of first heat conductive members 35 provided per tooth 33. As shown in Figure 3, the stator 3 includes a plurality of second heat conductive members 36 (4 in the illustrated example) for each first heat conductive member 35 provided per tooth 33. In other words, the stator 3 includes a number of second heat conductors 36 obtained by multiplying the number of first heat conductors 35 provided per tooth 33 by the number of second heat conductors 36 provided per first heat conductor 35, and then further multiplying that number by the number of teeth 33. The stator 3 includes a plurality (two in the illustrated example) of third heat conductors 38 for each tooth 33, as shown in Figure 3. In other words, the stator 3 includes a number of third heat conductors 38 obtained by multiplying the number of teeth 33 by the number of third heat conductors 38 provided per tooth 33. The stator 3 includes a plurality (two in the illustrated example) of insulating members 37 for each plurality of sets of corresponding coils 34, first heat conductors 35, second heat conductors 36, and third heat conductors 38, as shown in Figure 3. In other words, the stator 3 includes the same number of insulating members 37 as the first heat conductive member 35 and the third heat conductive member 38.

[0024] The stator core 31 is hollow and cylindrical. The stator core 31 is composed of a stator yoke 32 and a plurality of teeth 33. The stator core 31 has the function of transferring heat from the first heat conduction member 35 to the motor housing 4.

[0025] (2.2.1) Stator Yoke The stator yoke 32 is made of, for example, iron. The stator yoke 32 is formed in a hollow cylindrical shape. The outer surface of the stator yoke 32 is arranged concentrically with the rotor 2. That is, the central axis of the hollow cylindrical stator yoke 32 coincides with the axis Ax1 of the rotation axis 21 of the rotor yoke 22. In this embodiment, as shown in Figure 2, a regular nonagonal hole is provided in the center of the stator yoke 32. Note that the shape of this hole is not limited to a regular nonagon. It may be circular or a regular octagon. On the inner surface of the stator yoke 32, as shown in Figure 2, a plurality of teeth 33 protrude toward the rotation axis 21 so as to be arranged at equal intervals in the circumferential direction of the rotor yoke 22. In this embodiment, the teeth are configured to protrude from approximately the middle of each side of the regular nonagonal hole in the center of the stator yoke 32. Each of the plurality of teeth 33 is fixed to the stator yoke 32 by, for example, welding to the stator yoke 32.

[0026] (2.2.2) Teeth Each of the multiple teeth 33 is made of, for example, iron. Each of the multiple teeth 33 is arranged at equal intervals in the circumferential direction of the rotor yoke 22, as shown in Figure 2, and each of the multiple teeth 33 faces the rotor yoke 22 in the radial direction of the axis Ax1. When the rotor 2 is positioned inside the stator 3, the teeth 33 and the outer circumferential surface of the rotor 2 face each other with a gap in between.

[0027] In this embodiment, as shown in Figure 2, the multiple teeth 33 are arranged in a number corresponding to each side of the regular nonagonal hole in the center of the stator yoke 32 (nine in the illustrated example). Each of the multiple teeth 33 has a one-to-one correspondence with each of the multiple coils 34. That is, each of the multiple teeth 33 is provided with a coil 34 by winding a conductor 34a, which will be described later, around it. Furthermore, as shown in Figures 2 and 3, each of the multiple teeth 33 has two tooth protrusions 33a, two tooth side portions 33c, which will be described later, and two tooth convex side portions 33d, which will be described later, corresponding to each of the two tooth protrusions 33a. Note that each of the multiple teeth 33 does not have to have two tooth protrusions 33a and two tooth convex side portions 33d, which will be described later. Alternatively, it may have one tooth protrusion 33a and a tooth convex side portion 33d, which will be described later.

[0028] As shown in Figures 2 and 3, the two tooth protrusions 33a protrude in different directions from the tip of the tooth 33, which is located in the direction of the rotation axis 21 when viewed from the stator yoke 32, along the circumferential direction of the axis Ax1.

[0029] As shown in Figure 3, the side surface portion 33c of the tooth is the side surface of the tooth 33 along the second direction D2, which is the direction in which the second heat conductive member 36 protrudes from the first heat conductive member 35.

[0030] As shown in Figure 3, the tooth convex side portion 33d is the side of the tooth 33 along the tooth convex portion 33a and is adjacent to the tooth side portion 33c.

[0031] (2.2.3) Coils The coils 34 are edgewise windings constructed by winding multiple layers of flat rectangular wires made of, for example, copper or a copper alloy. In this embodiment, the conductor 34a is a flat rectangular wire without an insulating coating. As shown in Figure 2, the coil 34 is formed by winding the conductor 34a around the teeth 33. In the stator 3, the space factor of a coil 34 using a flat rectangular wire for the conductor 34a is larger than that of a coil 34 using a round wire or a rectangular wire for the conductor 34a. Note that the conductor 34a used to form the coil 34 is not limited to a flat rectangular wire without an insulating coating. It may be a round wire or a rectangular wire. Also, the conductor 34a may have an insulating coating.

[0032] Each of the multiple coils 34 has multiple layers that overlap in a first direction D1 with a first interval D3 between them, in the corresponding teeth 33 of the multiple teeth 33, as shown in Figure 3. The coil ends 34c, which are both ends of the conductor wires 34a constituting the coil 34, are drawn out in a downward direction parallel to the axial direction of the rotation axis 21, for example, as shown in Figure 2.

[0033] (2.2.4) First Heat Conductors Each of the plurality of first heat conductors 35 has electrical insulating properties and a greater thermal conductivity than the insulating member 37. Each of the plurality of first heat conductors 35 is made of, for example, aluminum nitride, alumina, etc. Each of the plurality of first heat conductors 35 is formed along the inner surface of the stator yoke 32 and the tooth side portion 33c and the tooth convex side portion 33d. That is, as shown in Figure 3, each of the plurality of first heat conductors 35 is formed in a U shape.

[0034] In this embodiment, the adhesive 39 is filled between each of the multiple first heat conductive members 35 and the stator core 31. That is, each of the multiple first heat conductive members 35 is bonded and fixed to the stator core 31 by the adhesive 39.

[0035] Since the first heat conduction member 35 has a higher thermal conductivity than the insulating member 37, its thermal resistivity is lower than that of the insulating member 37. In other words, the heat dissipation path that transmits heat generated in the coil 34 to the stator core 31 via the first heat conduction member 35 has better heat transfer efficiency than the heat dissipation path that goes through the insulating member 37. The first heat conduction member 35 also has the function of electrically insulating the coil 34 so that it does not come into contact with the stator core 31.

[0036] Based on the above, the first heat conduction member 35 has the function of efficiently transferring the heat generated in the coil 34 to the stator core 31 and the function of electrically insulating the coil 34 so that it does not come into contact with the stator core 31.

[0037] (2.2.5) Second Heat Conducting Members Each of the plurality of second heat conducting members 36 has electrical insulating properties and a greater thermal conductivity than the insulating member 37. Each of the plurality of second heat conducting members 36 is formed of, for example, aluminum nitride, alumina, etc. In this embodiment, it is formed of the same material as the first heat conducting member 35. Also, the thermal conductivity of the first heat conducting member 35 and the second heat conducting member 36 is the same. Note that the material used for the second heat conducting member 36 may be different from that of the first heat conducting member 35. Also, the first heat conducting member 35 and the second heat conducting member 36 may be integrally molded.

[0038] In this embodiment, each of the multiple second heat conductive members 36 is flat. However, the shape of each of the multiple second heat conductive members 36 is not limited to a flat shape. The shape of the multiple second heat conductive members 36 may be corrugated. Each of the multiple second heat conductive members 36 is provided in all of the multiple gaps in the coil 34 so that adjacent portions of the conductor 34a do not come into contact with each other. Also, in this embodiment, the thickness of the second heat conductive members 36 along the first direction D1 is the same. In the second heat conductive member 36, as shown in Figure 3, the tip portion 36a along the second direction D2 is connected to the third heat conductive member 38. However, the tip portion 36a does not have to be connected to the third heat conductive member 38.

[0039] Since the second heat conduction member 36 has a higher thermal conductivity than the insulating member 37, its thermal resistance is lower than that of the insulating member 37. In other words, the heat dissipation path that transfers heat generated in the coil 34 to the first heat conduction member 35 via the second heat conduction member 36 is more efficient for heat transfer than the path that goes through the insulating member 37. Similarly, the heat dissipation path that transfers heat generated in the coil 34 to the third heat conduction member 38 via the second heat conduction member 36 is more efficient for heat transfer than the path that goes through the insulating member 37. By providing the second heat conduction member 36 in the multiple gaps in the coil 34, it becomes possible to efficiently transfer the heat generated in the coil 34 to the first heat conduction member 35 and the third heat conduction member 38.

[0040] In this embodiment, the second heat conductive member 36, together with the first heat conductive member 35, serves as a substitute for the insulating coating of the conductor 34a by providing the second heat conductive member 36 in all of the multiple gaps in the coil 34. In other words, electrical insulation treatment of the conductor 34a becomes unnecessary.

[0041] Based on the above, the second heat conduction member 36 has the function of efficiently transferring the heat generated in the coil 34 to the first heat conduction member 35, and the function of electrically insulating adjacent parts of the conductor 34a so that they do not come into contact with each other.

[0042] (2.2.6) Third Heat Conducting Members Each of the plurality of third heat conducting members 38 has electrical insulating properties and a greater thermal conductivity than the insulating member 37. Each of the plurality of third heat conducting members 38 is formed of, for example, aluminum nitride, alumina, etc. In this embodiment, each of the plurality of third heat conducting members 38 is formed of the same material as the first heat conducting member 35. However, each of the plurality of third heat conducting members 38 does not have to be formed of the same material as the first heat conducting member 35.

[0043] Furthermore, as shown in Figure 3, each of the multiple third heat conductive members 38 is connected to the corresponding ends 35b of the first heat conductive member 35. Note that the third heat conductive members 38 do not necessarily have to be connected to the ends 35b of the first heat conductive member 35. Also, the first heat conductive member 35, the second heat conductive member 36, and the third heat conductive member 38 may be integrally molded.

[0044] (2.2.7) Insulating Member The insulating member 37 has electrical insulation properties. The insulating member 37 is, for example, an epoxy resin adhesive or a silicone adhesive or the like. The insulating member 37 is filled between the coil 34, the first heat conducting member 35, the second heat conducting member 36, and the third heat conducting member 38, and the coil 34, the first heat conducting member 35, the second heat conducting member 36, and the third heat conducting member 38 are adhered to each other.

[0045] That is, the insulating member 37 has a function of adhering the coil 34, the first heat conducting member 35, the second heat conducting member 36, and the third heat conducting member 38 to each other, and a function of electrically insulating adjacent portions of the conducting wire 34a from contacting each other.

[0046] (3) Heat Transfer Relationship Here, the heat transfer relationship through the first heat conducting member 35, the second heat conducting member 36, and the third heat conducting member 38 included in the stator 3 will be described.

[0047] In the present embodiment, each of the plurality of first heat conducting members 35 is formed along the inner surface of the stator yoke 32, the corresponding tooth side surface portion 33c, and the corresponding tooth convex side surface portion 33d. The first heat conducting member 35 has a higher thermal conductivity than the insulating member 37. That is, the first heat conducting member 35 is more likely to transfer heat than the insulating member 37. The heat generated in the coil 34 is transmitted to the stator core 31 and the motor housing 4 through the first heat conducting member 35. The first heat conducting member 35 transfers the heat generated in the coil 34 to the stator core 31 more quickly than the insulating member 37. The heat transferred to the stator core 31 finally reaches the motor housing 4.

[0048] Further, the plurality of second heat conducting members 36 are arranged in all the gaps of the layer of the conducting wire 34a. The second heat conducting member 36 has a higher thermal conductivity than the insulating member 37. That is, the second heat conducting member 36 is more likely to transfer heat than the insulating member 37. That is, a heat dissipation path to the plurality of first heat conducting members 35, which are more likely to transfer heat than the insulating member 37, is added, and heat dissipation to the motor housing 4 can be performed more easily and efficiently.

[0049] Furthermore, the third heat conduction member 38 is molded to be combined with both ends 35b of the first heat conduction member 35, which is molded in a U-shape. The third heat conduction member 38 has a higher thermal conductivity than the insulating member 37. In other words, the third heat conduction member 38 conducts heat more easily than the insulating member 37. This means that multiple heat dissipation paths to multiple first heat conduction members 35 corresponding to multiple third heat conduction members 38, which conduct heat more easily than the insulating member 37, are added, and heat dissipation to the motor housing 4 can be performed more easily and efficiently.

[0050] From the above, by including the first heat conductive member 35, the second heat conductive member 36, and the third heat conductive member 38 in the stator 3, the motor 1 can more efficiently dissipate the heat generated in the coil 34 without any processing of the coil 34.

[0051] (4) Advantages As described above, the motor 1 according to this embodiment comprises a rotor 2 and a stator 3, as shown in Figure 1. The rotor 2 includes a cylindrical rotor yoke 22 and permanent magnets 23. The rotor yoke 22 has a rotation axis 21 with axis Ax1 as the rotation center. The permanent magnets 23 are arranged on the side surface of the rotor yoke 22. The stator 3 includes a hollow cylindrical stator yoke 32, teeth 33, coils 34, a first heat conductive member 35, a second heat conductive member 36, an insulating member 37, and a third heat conductive member 38, as shown in Figure 3. The outer circumferential surface of the stator yoke 32 is arranged concentrically with the rotor 2. The teeth 33 protrude toward the rotation axis 21 from multiple positions in the circumferential direction of the rotor yoke 22 on the inner surface of the stator yoke 32. The coil 34 has a conductor 34a wound around teeth 33, and has a plurality of gaps between adjacent portions separated by a first interval D3 along a first direction D1 which is the winding axis direction of the conductor 34a. The first heat conductive member 35 is formed along the inner surface of the stator yoke 32 and the side surface of teeth 33. The second heat conductive member 36 protrudes from the first heat conductive member 35 so as to be provided in at least one of the plurality of gaps. The third heat conductive member 38 is combined with both ends 35b of the first heat conductive member 35 which are formed in a U shape. The insulating member 37 is filled between the coil 34, the first heat conductive member 35, the second heat conductive member 36, and the third heat conductive member 38. The first heat conductive member 35, the second heat conductive member 36, the insulating member 37, and the third heat conductive member 38 are electrically insulating. The first heat conductive member 35, the second heat conductive member 36, and the third heat conductive member 38 have higher thermal conductivity than the insulating member 37.

[0052] In this configuration, the first heat conduction member 35, the second heat conduction member 36, and the third heat conduction member 38 are formed as heat dissipation paths that have an electrical insulation function for the coil 34. In other words, it is possible to perform electrical insulation and heat dissipation simultaneously without processing the coil 34. That is, the heat generated in the coil 34 can be efficiently diffused without processing the coil 34.

[0053] (5) Modifications The following are examples of modifications. The modifications described below can be applied in appropriate combination with the above embodiments.

[0054] (5.1) Modification 1 In the above embodiment, the second heat conductive member 36 is provided in all of the multiple gaps in the coil 34, but the configuration is not limited to this. The second heat conductive member 36 may be provided in only one of the multiple gaps in the coil 34.

[0055] (5.2) Modification 2 In the above embodiment, the stator core 31 and the first heat conductive member 35 are fixed together with an adhesive, but the configuration is not limited to this.

[0056] Figure 4 is a schematic cross-sectional view showing the main parts of the motor 1 according to the modified example 2. For example, as shown in Figure 4, the first heat conduction member 35 may be fixed to the stator core 31 by fitting it in using the difference in thermal expansion coefficients. Specifically, the configuration is as follows. The stator core 31 is made of a material with a larger thermal expansion coefficient than the first heat conduction member 35. By heating or cooling either or both the stator core 31 and the first heat conduction member 35, the stator core 31 and the first heat conduction member 35 expand or contract. In other words, the first heat conduction member 35 can be fitted into the stator core 31 by utilizing the difference in thermal expansion coefficients between the stator core 31 and the first heat conduction member 35.

[0057] (5.3) Modification 3 In the above embodiment, the first heat conductive member 35 is fixed to the stator core 31 with an adhesive, but the configuration is not limited to this.

[0058] Figure 5 is a schematic cross-sectional view showing the main part of the motor 1 according to the modified example 3. For example, as shown in Figure 5, the first heat conductive member 35 may be fixed to the teeth 33 by crimping. Specifically, the configuration is as follows: The teeth 33 has a crimp recess 33b on the side surface 33c of the teeth. The first heat conductive member 35 has a crimp projection 35a that protrudes toward the side surface 33c of the teeth from the surface facing the side surface 33c of the teeth. The crimp recess 33b and the crimp projection 35a are provided so that they can be combined with each other. That is, the first heat conductive member 35 can be fixed to the teeth 33 by combining the crimp recess 33b and the crimp projection 35a by crimping.

[0059] (5.4) Modification 4 In this embodiment, the second heat conductive member 36 is provided in all of the multiple gaps in the coil 34, but the embodiment is not limited to this.

[0060] Figure 6 is a schematic cross-sectional view showing the main part of the motor 1 according to the modified example 4. For example, the second heat conductive member 36 may have the configuration shown in Figure 6. Specifically, in the first heat conductive member 35, the portion along the teeth 33 includes a first portion 35c, a second portion 35d, and a third portion 35e in order of proximity to the rotation axis 21. For example, in the first heat conductive member 35, the portion along the teeth 33 is divided into three parts: the first portion 35c, the second portion 35d, and the third portion 35e. Here, in the first heat conductive member 35, the portion along the teeth 33 may be divided into three equal parts. Note that the portion along the teeth 33 is not limited to a configuration of three divisions. It may be divided into four or five divisions. In this case, one or more second heat conductive members 36 are provided in at least one of the multiple gaps in the coil 34. At least one of the one or more second heat conductive members 36 may be configured to protrude from the second portion 35d. In other words, the first heat conductive member 35 may be configured such that the second heat conductive member 36 protrudes from the portion of the tooth 33 that is second closest to the rotation axis 21 among the three portions along the tooth 33. At least one of the one or more second heat conductive members 36 may protrude from the first portion 35c. Furthermore, at least one of the one or more second heat conductive members 36 may protrude from the third portion 35e.

[0061] (5.5) Modification 5 In this embodiment, as shown in Figure 3, the coil 34 is formed by winding multiple layers of conductors 34a, which are flat rectangular wires without an insulating coating, along the teeth 33 such that adjacent portions of the conductors 34a are separated by a first interval D3 from each other. However, the configuration is not limited to this.

[0062] Figure 7 is a schematic cross-sectional view showing the main part of the motor 1 according to the modified example 5. For example, as shown in Figure 7, the coil 34 may be formed by winding multiple layers of conductors 34b along the second heat conductive member 36 so as to separate adjacent portions of the conductors 34b, which are round wires without an insulating coating. Alternatively, the conductors 34b may be round wires with an insulating coating.

[0063] In modified example 5, as shown in Figure 7, the conductor 34b separates adjacent portions along the first direction D1. Furthermore, the conductor 34b separates adjacent portions along the second direction D2. For example, adjacent portions along the first direction D1 are separated by a first interval D3. Also, adjacent portions along the second direction D2 are separated by a second interval D4.

[0064] (5.6) Modification 6 In this embodiment, as shown in Figure 3, each of the multiple second heat conductive members 36 is provided such that the thickness along the first direction D1 of the second heat conductive member 36 is the same, but the configuration is not limited to this. Each of the multiple second heat conductive members 36 may have a different thickness along the first direction D1.

[0065] Figure 8 is a schematic cross-sectional view showing the main parts of the motor 1 according to the modified example 6. For example, the second heat conductive member 36 may have the configuration shown in Figure 8. Specifically, in the first heat conductive member 35, the portion along the teeth 33 includes a first portion 35c, a second portion 35d, and a third portion 35e in order of proximity to the rotation axis 21. For example, in the first heat conductive member 35, the portion along the teeth 33 is divided into three parts: the first portion 35c, the second portion 35d, and the third portion 35e. Here, in the first heat conductive member 35, the portion along the teeth 33 may be divided into three equal parts. Note that the portion along the teeth 33 is not limited to a configuration of three divisions. It may be divided into four or five parts. Three or more second heat conductive members 36 protrude from the first heat conductive member 35. The three or more second heat conduction members 36 include a second heat conduction member 36 protruding from the first portion 35c, a second heat conduction member 36 protruding from the second portion 35d, and a second heat conduction member 36 protruding from the third portion 35e. The second heat conduction member 36 protruding from the second portion 35d may have a greater thickness along the first direction D1 than the second heat conduction members 36 protruding from the first portion 35c and the third portion 35e. The second heat conduction member 36 protruding from the first portion 35c may have a greater thickness along the first direction D1 than the second heat conduction members 36 protruding from the second portion 35d and the third portion 35e. The second heat conduction member 36 protruding from the third portion 35e may have a greater thickness along the first direction D1 than the second heat conduction members 36 protruding from the first portion 35c and the second portion 35d.

[0066] (5.7) Modification 7 In this embodiment, as shown in Figure 3, the tip portion 36a of the second heat conductive member 36 along the second direction D2 is connected to the third heat conductive member 38, but the configuration is not limited to this. Each of the multiple second heat conductive members 36 may have a different length along the second direction D2.

[0067] Figure 9 is a schematic cross-sectional view showing the main part of the motor 1 according to the modified example 7. For example, the second heat conductive member 36 may also have a configuration as shown in Figure 9. Specifically, in the first heat conductive member 35, the portion along the teeth 33 includes a first portion 35c, a second portion 35d, and a third portion 35e in order of proximity to the rotation axis 21. For example, in the first heat conductive member 35, the portion along the teeth 33 is divided into three parts: the first portion 35c, the second portion 35d, and the third portion 35e. Here, in the first heat conductive member 35, the portion along the teeth 33 may be divided into three equal parts. Note that the portion along the teeth 33 is not limited to a configuration of three divisions. It may be divided into four or five parts. Three or more second heat conductive members 36 protrude from the first heat conductive member 35. The three or more second heat conduction members 36 include a second heat conduction member 36 protruding from a first portion 35c, a second heat conduction member 36 protruding from a second portion 35d, and a second heat conduction member 36 protruding from a third portion 35e. The second heat conduction member 36 protruding from the second portion 35d may have a longer length along the second direction D2 than the second heat conduction members 36 protruding from the first portion 35c and the third portion 35e. The second heat conduction member 36 protruding from the first portion 35c may have a longer length along the second direction D2 than the second heat conduction members 36 protruding from the second portion 35d and the third portion 35e. The second heat conduction member 36 protruding from the third portion 35e may have a longer length along the second direction D2 than the second heat conduction members 36 protruding from the first portion 35c and the second portion 35d.

[0068] (5.8) Modification 8 In this embodiment, the second heat conduction member 36 is configured to have the same thermal conductivity as the first heat conduction member 35, but the configuration is not limited to this. Each of the multiple second heat conduction members 36 may be made of a material that has a different thermal conductivity than the first heat conduction member 35.

[0069] For example, the second heat conduction member 36 may have the following configuration. Specifically, in the first heat conduction member 35, the portion along the teeth 33 includes a first portion 35c, a second portion 35d, and a third portion 35e in order of proximity to the rotation axis 21. For example, in the first heat conduction member 35, the portion along the teeth 33 is divided into three parts: a first portion 35c, a second portion 35d, and a third portion 35e. Here, in the first heat conduction member 35, the portion along the teeth 33 may be divided into three equal parts. Note that the portion along the teeth 33 is not limited to a configuration of three divisions. It may be divided into four or five parts. Three or more second heat conduction members 36 protrude from the first heat conduction member 35. Three or more second heat conduction members 36 include a second heat conduction member 36 protruding from the first portion 35c, a second heat conduction member 36 protruding from the second portion 35d, and a second heat conduction member 36 protruding from the third portion 35e. The second heat conduction member 36 protruding from the second portion 35d may have a higher thermal conductivity than the second heat conduction member 36 protruding from the first portion 35c and the third portion 35e. Furthermore, the second heat conduction member 36 protruding from the first portion 35c may have a higher thermal conductivity than the second heat conduction member 36 protruding from the second portion 35d and the third portion 35e. Similarly, the second heat conduction member 36 protruding from the third portion 35e may have a higher thermal conductivity than the second heat conduction member 36 protruding from the first portion 35c and the second portion 35d.

[0070] (5.9) Modification 9 In the above embodiment, each of the plurality of first heat conductive members 35 is formed in a U-shape along the inner surface of the stator yoke 32 and the tooth side portion 33c and the tooth convex side portion 33d, but is not limited thereto. Each of the plurality of first heat conductive members 35 may have a shape along the inner surface of the stator yoke 32 and the corresponding tooth side portion 33c.

[0071] (5.10) Modification 10 In the above embodiment, the third heat conductive member 38 is made of the same material as the first heat conductive member 35, but is not limited to this. The third heat conductive member 38 may have a lower thermal conductivity than the first heat conductive member 35 and the second heat conductive member 36.

[0072] By making the thermal conductivity of the third heat conduction member 38 lower than that of the first heat conduction member 35 and the second heat conduction member 36, the heat transferred to the third heat conduction member 38 is more easily transferred from the third heat conduction member 38 to the first heat conduction member 35 and the second heat conduction member 36.

[0073] (5.11) Modification 11 In the above embodiment, the stator 3 is configured to further include a third heat conductive member 38, but is not limited to this configuration. The stator 3 may also be configured without the third heat conductive member 38.

[0074] (Summary) As described above, the motor (1) of the first embodiment comprises a rotor (2) and a stator (3). The rotor (2) includes a cylindrical rotor yoke (22) and permanent magnets (23). The rotor yoke (22) has a rotation axis (21) with the axis (Ax1) as the center of rotation. The permanent magnets (23) are arranged on the side surface of the rotor yoke (22). The stator (3) includes a hollow cylindrical stator yoke (32), teeth (33), coils (34), a first heat conductive member (35), a second heat conductive member (36), and an insulating member (37). The outer circumferential surface of the stator yoke (32) is arranged concentrically with the rotor (2). The teeth (33) protrude toward the rotation axis (21) from multiple positions in the circumferential direction of the rotor yoke (22) on the inner surface of the stator yoke (32). The coil (34) has wires (34a; 34b) wound around teeth (33), and has multiple gaps that separate adjacent portions of the wires (34a; 34b). The first heat conduction member (35) is formed along the inner surface of the stator yoke (32) and the side surface of the teeth (33). The second heat conduction member (36) protrudes from the first heat conduction member (35) so as to be provided in at least one of the multiple gaps. The insulating member (37) is filled between the coil (34), the first heat conduction member (35), and the second heat conduction member (36). The first heat conduction member (35), the second heat conduction member (36), and the insulating member (37) are electrically insulating. The first heat conduction member (35) and the second heat conduction member (36) have a higher thermal conductivity than the insulating member (37).

[0075] According to this embodiment, the first heat conductive member (35) and the second heat conductive member (36) are formed as a heat dissipation path that has an electrical insulation function for the coil (34). In other words, it is possible to perform electrical insulation treatment and heat dissipation treatment simultaneously without performing any processing on the coil (34). That is, the heat generated in the coil (34) can be efficiently diffused without performing any processing on the coil (34).

[0076] In the motor (1) of the second embodiment, the first heat conductive member (35) is fixed to the stator yoke (32) and teeth (33) by adhesive (39).

[0077] According to this embodiment, the first heat conductive member (35) can be fixed to the stator yoke (32) and teeth (33) by adhesive (39).

[0078] In the motor (1) of the third embodiment, in the first or second embodiment, the stator yoke (32) and teeth (33) have a greater coefficient of thermal expansion than the first heat conductive member (35).

[0079] According to this embodiment, the difference in thermal expansion coefficients between the stator core (31) and the first heat conduction member (35) can be used to heat or cool the stator core (31) and the first heat conduction member (35), and the first heat conduction member (35) can be fixed to the stator core (31).

[0080] In the motor (1) of the fourth embodiment, in any of the first to third embodiments, the teeth (33) have crimped recesses (33b) on their sides along the circumferential direction of the rotating shaft (21). The first heat conductive member (35) has a crimped projection (35a) on the surface facing the teeth (33) that protrudes toward the teeth (33). The first heat conductive member (35) is fixed to the teeth (33) by crimping the crimped recess (33b) and the crimped projection (35a) together.

[0081] According to this embodiment, the first heat conductive member (35) can be fixed to the teeth (33) by combining the crimped recess (33b) of the teeth (33) and the crimped protrusion (35a) of the first heat conductive member (35) through a crimping process.

[0082] In the motor (1) of the fifth embodiment, the second heat conductive member (36) is formed on a flat plate in any of the first to fourth embodiments.

[0083] According to this embodiment, by making the second heat conductive member (36) flat, the conductors (34a; 34b) can be easily spaced apart from adjacent portions along the first direction (D1).

[0084] In the motor (1) of the sixth embodiment, the first heat conductive member (35) and the second heat conductive member (36) are integrally molded in any of the first to fifth embodiments.

[0085] According to this embodiment, the first heat conductive member (35) and the second heat conductive member (36) can be molded as a single unit.

[0086] In the seventh embodiment of the motor (1), in any of the first to sixth embodiments, the portion of the first heat conductive member (35) along the teeth (33) includes a first portion (35c), a second portion (35d), and a third portion (35e) in order of proximity to the rotation axis (21). One or more second heat conductive members (36) protrude from the first heat conductive member (35). At least one of the one or more second heat conductive members (36) protrudes from the second portion (35d).

[0087] According to this embodiment, for example, heat can be efficiently dissipated by making the part to be heated protrude.

[0088] In the motor (1) of the eighth embodiment, in any of the first to seventh embodiments, the portion of the first heat conductive member (35) along the teeth (33) includes a first portion (35c), a second portion (35d), and a third portion (35e) in order of proximity to the rotation axis (21). Three or more second heat conductive members (36) protrude from the first heat conductive member (35). The three or more second heat conductive members (36) include a second heat conductive member (36) protruding from the first portion (35c), a second heat conductive member (36) protruding from the second portion (35d), and a second heat conductive member (36) protruding from the third portion (35e). The second heat conductive member (36) protruding from the second portion (35d) has a greater thickness along the winding axis of the conductor (34a; 34b) than the second heat conductive members (36) protruding from the first portion (35c) and the third portion (35e).

[0089] According to this embodiment, for example, by increasing the thickness of the second heat conduction member (36) in the part where heat is to be dissipated, heat can be dissipated efficiently.

[0090] In the motor (1) of the ninth embodiment, in any of the first to eighth embodiments, the portion of the first heat conductive member (35) along the teeth (33) includes a first portion (35c), a second portion (35d), and a third portion (35e) in order of proximity to the rotation axis (21). Three or more second heat conductive members (36) protrude from the first heat conductive member (35). The three or more second heat conductive members (36) include a second heat conductive member (36) protruding from the first portion (35c), a second heat conductive member (36) protruding from the second portion (35d), and a second heat conductive member (36) protruding from the third portion (35e). The second heat conductive member (36) protruding from the second portion (35d) has a longer length in the direction of protrusion from the first heat conductive member (35) than the second heat conductive members (36) protruding from the first portion (35c) and the third portion (35e).

[0091] According to this embodiment, for example, by increasing the length of the second heat conduction member (36) in the part to be heated, heat can be dissipated efficiently.

[0092] In the motor (1) of the tenth embodiment, in any of the first to ninth embodiments, the portion of the first heat conductive member (35) along the teeth (33) includes a first portion (35c), a second portion (35d), and a third portion (35e) in order of proximity to the rotation axis (21). Three or more second heat conductive members (36) protrude from the first heat conductive member (35). The three or more second heat conductive members (36) include a second heat conductive member (36) protruding from the first portion (35c), a second heat conductive member (36) protruding from the second portion (35d), and a second heat conductive member (36) protruding from the third portion (35e). The second heat conductive member (36) protruding from the second portion (35d) has a higher thermal conductivity than the second heat conductive members (36) protruding from the first portion (35c) and the third portion (35e).

[0093] According to this embodiment, for example, by increasing the thermal conductivity of the second heat conduction member (36) in the part to be heated, heat can be dissipated efficiently.

[0094] In the motor (1) of the eleventh embodiment, in any of the first to tenth embodiments, the first heat conduction member (35) is formed in a U-shape. The stator (3) is combined with both ends (35b) of the first heat conduction member (35) and further includes a third heat conduction member (38) which has electrical insulating properties and a thermal conductivity higher than that of the insulating member (37).

[0095] According to this embodiment, by providing the third heat conduction member (38), the number of paths for transferring heat generated in the coil (34) to the first heat conduction member (35) is increased, so that the heat generated in the coil (34) can be dissipated efficiently.

[0096] In the motor (1) of the twelfth embodiment, in any of the first to eleventh embodiments, the third heat conduction member (38) has a lower thermal conductivity than the first heat conduction member (35) and the second heat conduction member (36).

[0097] According to this embodiment, by providing a difference in thermal conductivity between the first heat conductive member (35), the second heat conductive member (36), and the third heat conductive member (38), the heat generated in the coil (34) can be efficiently dissipated.

[0098] In the motor (1) of the 13th embodiment, in any of the first to 12th embodiments, the stator (3) includes a plurality of teeth (33). The stator (3) includes a plurality of coils (34) corresponding to each of the plurality of teeth (33). The stator (3) includes a plurality of first heat conductors (35) corresponding to each of the plurality of teeth (33). The stator (3) includes a plurality of second heat conductors (36) corresponding to each of the plurality of first heat conductors (35). The stator (3) includes a plurality of insulating members (37) that fill each of the plurality of sets of the coils (34), first heat conductors (35), and second heat conductors (36) that correspond to each other.

[0099] According to this embodiment, by providing multiple teeth (33), coils (34), first heat conductive members (35), second heat conductive members (36), and insulating members (37) to the stator (3), the heat generated by the coils (34) can be dissipated more efficiently.

[0100] The motor of this disclosure allows for efficient dissipation of heat generated in the coil without requiring any processing of the coil. Therefore, the motor of this disclosure is inexpensive, has excellent heat dissipation characteristics, and can be used in various products such as industrial machinery and robots, improving their heat dissipation characteristics and reducing manufacturing costs. Thus, the motor of this disclosure is industrially useful.

[0101] 1 Motor 2 Rotor 3 Stator 21 Rotating shaft 22 Rotor yoke 23 Permanent magnet 32 ​​Stator yoke 33 Teeth 33b Crimped recess 34 Coil 34a, 34b Conductor wire 35 First heat conductive member 35a Crimped protrusion 35b Both ends 35c First part 35d Second part 35e Third part 36 Second heat conductive member 37 Insulating member 38 Third heat conductive member 39 Adhesive Ax1 Axle

Claims

1. A rotor and a stator, wherein the rotor includes a cylindrical rotor yoke having a rotation axis with its axis as the center of rotation, and permanent magnets disposed on the side surface of the rotor yoke, the stator includes a hollow cylindrical stator yoke whose outer surface is concentric with the rotor, teeth projecting from the circumferential position of the rotor yoke toward the rotation axis on the inner surface of the stator yoke, a coil in which a conductor is wound around the teeth and which has a plurality of gaps that separate adjacent portions of the conductor, a first heat conductive member formed along the inner surface of the stator yoke and the side surface of the teeth, a second heat conductive member projecting from the first heat conductive member so as to be provided in at least one of the plurality of gaps, and an insulating member filled between the coil, the first heat conductive member and the second heat conductive member, the first heat conductive member, and the insulating member having electrical insulating properties. A motor in which the first heat conductive member and the second heat conductive member have a higher thermal conductivity than the insulating member.

2. The motor according to claim 1, wherein the first heat conductive member is fixed to the stator yoke and the teeth with an adhesive.

3. The motor according to claim 1, wherein the stator yoke and the teeth have a greater coefficient of thermal expansion than the first heat conductive member.

4. The motor according to claim 1, wherein the teeth have crimp recesses on their sides along the circumferential direction of the rotating shaft, the first heat conductive member has crimp protrusions on its surface facing the teeth that project toward the teeth, and the first heat conductive member is fixed to the teeth by crimping the crimp recess and the crimp protrusion together.

5. The motor according to claim 1, wherein the second heat conductive member is formed into a flat plate shape.

6. The motor according to claim 1, wherein the first heat conductive member and the second heat conductive member are integrally molded.

7. The motor according to claim 1, wherein the portion along the teeth of the first heat conductive member includes a first portion, a second portion, and a third portion in order of proximity to the axis of rotation, one or more second heat conductive members protrude from the first heat conductive member, and at least one of the one or more second heat conductive members protrudes from the second portion.

8. The motor according to claim 1, wherein the portion along the teeth of the first heat conductive member includes a first portion, a second portion, and a third portion in order of proximity to the rotation axis, and three or more second heat conductive members protrude from the first heat conductive member, and the three or more second heat conductive members include a second heat conductive member protruding from the first portion, a second heat conductive member protruding from the second portion, and a second heat conductive member protruding from the third portion, and the second heat conductive member protruding from the second portion has a greater thickness in the direction of the winding axis of the conductor than the second heat conductive members protruding from the first portion and the third portion.

9. The motor according to claim 1, wherein the portion along the teeth of the first heat conduction member includes a first portion, a second portion, and a third portion in order of proximity to the axis of rotation, and three or more second heat conduction members protrude from the first heat conduction member, and the three or more second heat conduction members include a second heat conduction member protruding from the first portion, a second heat conduction member protruding from the second portion, and a second heat conduction member protruding from the third portion, and the length of the second heat conduction member protruding from the second portion is greater in the direction of protrusion from the first heat conduction member than the length of the second heat conduction members protruding from the first portion and the second heat conduction members protruding from the third portion.

10. The motor according to claim 1, wherein the portion along the teeth of the first heat conductive member includes a first portion, a second portion, and a third portion in order of proximity to the axis of rotation, and three or more second heat conductive members protrude from the first heat conductive member, and the three or more second heat conductive members include a second heat conductive member protruding from the first portion, a second heat conductive member protruding from the second portion, and a second heat conductive member protruding from the third portion, and the second heat conductive member protruding from the second portion has a higher thermal conductivity than the second heat conductive members protruding from the first portion and the third portion.

11. The motor according to claim 1, wherein the first heat conductive member is formed in a U-shape, and the stator further includes a third heat conductive member which is combined with both ends of the first heat conductive member, has electrical insulating properties, and has a thermal conductivity higher than that of the insulating member.

12. The motor according to claim 11, wherein the third heat conductive member has a lower thermal conductivity than the first heat conductive member and the second heat conductive member.

13. The motor according to claim 1, wherein the stator includes a plurality of teeth, a plurality of coils corresponding to each of the plurality of teeth, a plurality of first heat conductive members corresponding to each of the plurality of teeth, a plurality of second heat conductive members corresponding to each of the plurality of first heat conductive members, and a plurality of insulating members that fill each of a plurality of sets of the coils, first heat conductive members and second heat conductive members that correspond to each other.

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