Radial Gap Motor

Abstract

To provide a radial gap motor that enables significant weight lightening and cost reducing.SOLUTION: A motor 1 includes a reactor 6. A rotor core 31 is made of a magnetic material having magnetic isotropy. The reactor 6 comprises a pair of reactor cores 61, 71 that are disposed to respectively face both end surfaces 313, 314 of the rotor core 31 in an axial direction, and reactor coils 62, 63 and reactor coils 72, 73 that are respectively wound about the reactor core 61 and the reactor core 71 of the pair of reactor cores 61, 71. For example, the reactor core 61 includes a ring part 611 that is wound by the reactor coils 62, 63, and projection parts 612, 613 that protrude from the ring part 611 to the end surface 313 which is one of the end surfaces of the rotor core 31. A magnetic flux generated in the rind part 611 while the reactor coils 62, 63 are engendered passes from the projection part 613 of the reactor core 61 which is one of the pair of the reactor cores 61, 71 to the projection part 713 of the reactor core 71 which is the other of the pair of the reactor cores 61, 71.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] In electric vehicles that use an electric motor as a power source, a converter that boosts the battery voltage is used in the drive circuit of the motor. One of the key components of the converter is the reactor. In order to make the reactor smaller and lighter, development is being carried out on high-performance soft magnetic materials used in the reactor, as well as on the cooling structure and mechanical structure of the reactor.

[0003] Patent Document 1 discloses a reluctance motor having a space on the radially inner side of a rotor core, in which a reactor is disposed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-174459 A Summary of the Invention [Problem to be solved by the invention]

[0005] Although the technology disclosed in Patent Document 1 can reduce the volume of the space occupied by the motor and the reactor, it is difficult to dramatically reduce the weight due to the weight of the reactor core installed in the space. In addition, with the technology disclosed in Patent Document 1, it is difficult to dramatically reduce the cost due to the cost of the reactor core, etc.

[0006] The present invention has been made in view of the above, and has an object to provide a radial gap motor that can dramatically reduce weight and costs. [Means for solving the problem]

[0007] In order to solve the above problems, the radial gap motor of the present invention is a radial gap motor including a rotor and a stator, the radial gap motor further including a reactor, the rotor has a rotor core that rotates in a circumferential direction of a rotation shaft of the radial gap motor, the stator has a stator core and a stator coil wound around the stator core, at least one of the motor cores of the rotor core and the stator core is molded from a magnetic material having magnetic isotropy, and the reactor is disposed between both ends of the one motor core in the axial direction of the rotation shaft. the pair of reactor cores are arranged facing each other on one side of the motor core, and a reactor coil is wound around each of the pair of reactor cores, each of the pair of reactor cores has a ring portion around which the reactor coil is wound and extending in the circumferential direction, and a protrusion protruding from a part of the ring portion toward the end face of one of the motor cores, and the pair of reactor cores and the reactor coil are arranged so that magnetic flux generated in the ring portion when current is applied to the reactor coil passes from the protrusion of one reactor core to the protrusion of the other reactor core.

[0008] With this configuration, one motor core made of a magnetic material having magnetic isotropy can cooperate with one reactor core and the other reactor core to form a closed magnetic circuit that passes magnetic flux in the axial direction between the one reactor core and the other reactor core. In other words, the one motor core can not only pass magnetic flux in the radial direction to rotate the rotor, but also pass magnetic flux in the axial direction to ensure the energy storage function of the reactor.

[0009] The rotor cores and stator cores of conventional radial gap motors often have a structure in which electromagnetic steel sheets or amorphous foils that extend in the radial direction are laminated in the axial direction. Due to this laminated structure, conventional rotor cores and stator cores are limited to forming a two-dimensional magnetic circuit that only allows magnetic flux to flow mainly in the radial direction.

[0010] In contrast, the one motor core of the present invention can form a three-dimensional magnetic circuit that can not only pass magnetic flux in the radial direction to drive the rotor to rotate, but also pass magnetic flux in the axial direction to ensure the energy storage function of the reactor. As a result, the radial gap motor of the present invention can share a part of the one motor core as the reactor core, so that the weight and cost of the reactor core can be reduced. The cooling structure of the reactor can be integrated with the cooling structure of the rotor and the stator, so that the weight and cost of the cooling structure of the motor can be reduced. Moreover, since the one motor core of the present invention can form a three-dimensional magnetic circuit as described above, the design freedom of the magnetic circuit is improved. As a result, the one motor core of the present invention can easily form a magnetic circuit that can suppress interference between the magnetic flux that drives the rotor to rotate and the magnetic flux generated in the reactor and passing through the one motor core. Therefore, the radial gap motor of the present invention can reduce the weight and cost of the reactor core and the weight and cost of the cooling structure of the motor without impairing the functions of the motor and the reactor. Therefore, the radial gap motor of the present invention can dramatically reduce weight and cost.

[0011] In a further preferred embodiment, a pair of the reactor coils are wound around the ring portion, and the winding directions of the pair of reactor coils are opposite to each other.

[0012] According to this aspect, each of the pair of reactor cores can easily merge the magnetic flux generated in the ring portion when one of the reactor coils is energized and the magnetic flux generated in the ring portion when the other of the reactor coils is energized toward a specific protruding portion, simply by winding the reactor coil, without complicating the electric circuit of the converter. The magnetic flux merged at the specific protruding portion flows from the one of the reactor cores having this protruding portion through the one of the motor cores to the protruding portion of the other of the reactor cores. Therefore, the one of the motor cores of the present invention can easily form a closed magnetic path that allows the magnetic flux to pass between the one of the reactor cores and the other of the reactor cores. Therefore, the radial gap motor of the present invention can easily reduce the weight and cost of the reactor core and the weight and cost of the cooling structure of the motor. Therefore, the radial gap motor of the present invention can dramatically and easily achieve weight reduction and cost reduction.

[0013] In a further preferred embodiment, the magnetic material is soft magnetic metal powder with an insulating coating.

[0014] In this embodiment, the degree of freedom in shape of the one motor core is improved, so that the above-mentioned three-dimensional magnetic circuit can be formed more easily. Therefore, the radial gap motor of the present invention can more easily reduce the weight and cost of the reactor core and the weight and cost of the motor cooling structure. Therefore, the radial gap motor of the present invention can dramatically and easily achieve weight and cost reduction. Effect of the Invention

[0015] According to the present invention, it is possible to provide a radial gap motor that can dramatically reduce weight and cost. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is an external perspective view of a radial gap motor according to a first embodiment. [Diagram 2]FIG. 2 is a top view of the rotor and the stator shown in FIG. 1 as viewed from the axial direction. [Diagram 3] FIG. 2 is a perspective view of the reactor shown in FIG. [Figure 4] FIG. 2 is a schematic cross-sectional view of the radial gap motor shown in FIG. [Diagram 5] FIG. 2 is a diagram (part 1) showing a magnetic circuit formed by each core of the rotor, the stator, and the reactor shown in FIG. [Figure 6] FIG. 2 is a diagram (part 2) showing a magnetic circuit formed by each core of the rotor, the stator, and the reactor shown in FIG. [Figure 7] FIG. 2 is a diagram showing an electric circuit for driving the radial gap motor shown in FIG. 1. [Figure 8] FIG. 6 is a schematic cross-sectional view of a radial gap motor according to a second embodiment. [Figure 9] FIG. 9 is a diagram (part 1) showing a magnetic circuit formed by each core of the rotor, the stator, and the reactor shown in FIG. [Figure 10] 9 is a diagram (part 2) showing a magnetic circuit formed by each core of the rotor, the stator, and the reactor shown in FIG. 8. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Components with the same reference numerals in each embodiment have the same functions in each embodiment unless otherwise specified, and description thereof will be omitted.

[0018] [Embodiment 1] A radial gap motor 1 of the first embodiment will be described with reference to FIGS.

[0019] In this embodiment, the direction going around the rotating shaft 2 of the radial gap motor 1 (symbol θ in FIG. 1) is also simply referred to as the "circumferential direction." In this embodiment, the axial direction of the rotating shaft 2 of the radial gap motor 1 (symbol z in FIG. 1) is also simply referred to as the "axial direction." In this embodiment, the radial direction of the rotating shaft 2 of the radial gap motor 1 (symbol r in FIG. 1) is also simply referred to as the "radial direction."

[0020] FIG. 1 is an external perspective view of a radial gap motor 1 of a first embodiment. FIG. 2 is a top view of a rotor 3 and a stator 4 shown in FIG. 1 as viewed from the axial direction. In FIG. 2, a reactor 6 is omitted. FIG. 3 is a perspective view of the reactor 6 shown in FIG. 1. In FIG. 3, the rotor 3 is shown by a virtual line, and the rotating shaft 2 and the stator 4 are omitted. FIG. 4 is a schematic cross-sectional view of the radial gap motor 1 shown in FIG. 1. FIG. 4 shows a schematic cross-section of the motor 1 along the axial direction.

[0021] The radial gap motor 1 (hereinafter also referred to as "motor 1") includes a rotor 3, a stator 4, and a reactor 6. The motor 1 is an electric motor in which a gap 5 is provided between the rotor 3 and the stator 4 in the radial direction. The motor 1 is not particularly limited as long as it is a radial gap motor including the reactor 6. As an example of the motor 1, in this embodiment, an SPM type AC motor in which a permanent magnet 32 ​​is fixed to the surface of an outer circumferential portion 311 of a rotor core 31 will be described. The motor 1 may also be an IPM type AC motor in which a permanent magnet 32 ​​is embedded inside the outer circumferential portion 311 of the rotor core 31.

[0022] The rotor 3 has a rotor core 31 and a permanent magnet 32. The rotor core 31 has a cylindrical shape fixed to the rotating shaft 2 so that its central axis coincides with the rotating shaft 2. The rotor core 31 rotates in the circumferential direction of the rotating shaft 2. The rotor core 31 has an outer peripheral portion 311 and a main portion 312. The outer peripheral portion 311 is a portion of the rotor core 31 that is separated from the rotating shaft 2 in the radial direction. The main portion 312 is a portion of the rotor core 31 that is closer to the rotating shaft 2 in the radial direction than the outer peripheral portion 311. The permanent magnet 32 ​​is fixed to the surface of the outer peripheral portion 311 of the rotor core 31 (the outer peripheral surface of the rotor core 31).

[0023] The stator 4 has a stator core 41 and a stator coil 42. The stator core 41 has a cylindrical shape whose central axis coincides with the rotating shaft 2 and covers the rotor 3 in the circumferential direction. The stator core 41 is fixed to a casing (not shown). The stator core 41 has teeth 411 and a yoke 413. A plurality of teeth 411 are formed on the inner peripheral portion of the stator core 41 at intervals in the circumferential direction and extend from the yoke 413 inward in the axial direction. A slot 412 is formed between adjacent teeth 411, 411. The yoke 413 is a portion of the stator core 41 that is farther away from the rotating shaft 2 in the radial direction than the teeth 411 and the slots 412. The yoke 413 is an outer peripheral portion of the stator core 41.

[0024] The stator coil 42 is a coil wound around the stator core 41. The stator coil 42 is housed in the slots 412 and wound around the teeth 411. The winding method of the stator coil 42 (distributed winding, concentrated winding, single-layer winding, two-layer winding, etc.) is not particularly limited. Note that, although the illustration of the stator coil 42 is simplified in FIG. 2 as if it were housed in only some of the slots 412, the stator coil 42 is housed in all of the slots 412.

[0025] At least one of the two motor cores (hereinafter also referred to as "one motor core") consisting of the rotor core 31 and the stator core 41 is made of a magnetic material having magnetic isotropy. The "magnetic material having magnetic isotropy" refers to a magnetic material in which the magnetization easy axis of the crystal grains of the magnetic material is not aligned in a specific direction and the magnetic properties are isotropic. The magnetic material having magnetic isotropy is, for example, soft magnetic metal powder with an insulating coating. That is, the one motor core may be a powder magnetic core. In this embodiment, the rotor core 31 is made of a magnetic material having magnetic isotropy and corresponds to one motor core of the present invention. In the second embodiment, the stator core 41 is made of a magnetic material having magnetic isotropy and corresponds to one motor core of the present invention.

[0026] 3, the reactor 6 has a pair of reactor cores 61, 71 and reactor coils 62, 63, 72, 73. The pair of reactor cores 61, 71 are disposed opposite both end faces 313, 314 of the rotor core 31 in the axial direction, respectively. The reactor coils 62, 63 are wound around one of the reactor cores 61. The reactor coils 72, 73 are wound around the other of the reactor cores 71.

[0027] In this embodiment, a pair of reactor cores 61, 71 and reactor coils 62, 63, 72, 73 are provided so that a magnetic flux generated in a ring portion 611 when current is applied to the reactor coils 62, 63 wound around one reactor core 61 passes from a protrusion portion 613 (described later) of one reactor core 61 to a protrusion portion 713 (described later) of the other reactor core 71.

[0028] The reactor core 61 has a ring shape with its central axis coinciding with the rotating shaft 2. The reactor core 61 is disposed facing one end surface 313 of the rotor core 31. The reactor core 61 is fixed to a casing (not shown). The reactor core 61 has a ring portion 611 and a pair of protruding portions 612, 613. The pair of reactor coils 62, 63 are wound around the ring portion 611, and the ring portion 611 has a ring shape extending in the circumferential direction. Each of the pair of protruding portions 612, 613 protrudes from a part of the ring portion 611 toward the one end surface 313 of the rotor core 31. The tip surfaces of each of the pair of protruding portions 612, 613 in the axial direction face the one end surface 313 of the rotor core 31 with a gap 65 therebetween. The pair of protruding portions 612, 613 have a symmetrical shape with respect to the rotating shaft 2, and are disposed at equal intervals in the circumferential direction of the ring portion 611.

[0029] The pair of reactor coils 62, 63 are arranged to be aligned in the circumferential direction of the ring portion 611 via the protruding portion 612 or the protruding portion 613. For example, one reactor coil 62 is wound around one arc portion 611a of the ring portion 611 located between the protruding portions 612 and 613. The other reactor coil 63 is wound around the other arc portion 611b of the ring portion 611 located between the protruding portions 612 and 613. The winding directions of the pair of reactor coils 62, 63 are opposite to each other when viewed in the circumferential direction.

[0030] The reactor core 71 has a ring shape similar to the reactor core 61, and is disposed to face the other end surface 314 of the rotor core 31, which is the one of the motor cores. The reactor core 71 has a ring portion 711 around which a pair of reactor coils 72, 73 are wound and extends in the circumferential direction, similar to the reactor core 61, and a pair of protruding portions 712, 713 protruding from a part of the ring portion 711 toward the other end surface 314 of the rotor core 31, which is the one of the motor cores. The tip surfaces of the pair of protruding portions 712, 713 in the axial direction face the other end surface 314 of the rotor core 31 with a gap 75 therebetween, similar to the pair of protruding portions 612, 613. The pair of reactor coils 72, 73 are disposed to be aligned in the circumferential direction of the ring portion 711 via the protruding portion 712 or the protruding portion 713, similar to the pair of reactor coils 62, 63. The winding directions of the pair of reactor coils 72, 73 are opposite to each other when viewed in the circumferential direction.

[0031] When the reactor coils 62 and 63 are energized, magnetic fluxes M61 and M62 are generated in the ring portion 611, passing through the ring portion 611 and heading toward the protruding portion 613. Since the protruding portion 613 is disposed facing one end face 313 of the rotor core 31, the magnetic fluxes M61 and M62 generated in the ring portion 611 join together at the protruding portion 613 and flow from the protruding portion 613 into the one end face 313 of the rotor core 31. Since the rotor core 31 is formed from a magnetic material having magnetic isotropy, the magnetic flux M63 that has flowed into the one end face 313 of the rotor core 31 passes through the rotor core 31 along the axial direction. Since the protruding portion 713 of the other reactor core 71 is disposed facing the other end face 314 of the rotor core 31, the magnetic flux M63 passing through the rotor core 31 flows from the other end face 314 into the protruding portion 713. The magnetic flux M63 that has flowed into the protruding portion 713 is divided into magnetic fluxes M64 and M65 at the protruding portion 713 and passes through the ring portion 711 of the other reactor core 71. The magnetic fluxes M64 and M65 that pass through the ring portion 711 are amplified when the reactor coils 72 and 73 are energized and head toward the protruding portion 712. The magnetic fluxes M64 and M65 heading toward the protruding portion 712 join together at the protruding portion 712 and flow from the protruding portion 712 into the other end surface 314 of the rotor core 31. The magnetic flux M66 that has flowed into the other end surface 314 passes through the rotor core 31 along the axial direction. The magnetic flux M66 that passes through the rotor core 31 flows from one end surface 313 into the protruding portion 613.

[0032] In this manner, in the motor 1, the rotor core 31 formed from a magnetic material having magnetic isotropy can cooperate with one reactor core 61 and the other reactor core 71 to form a closed magnetic circuit that passes the magnetic fluxes M63, M66 in the axial direction between the one reactor core 61 and the other reactor core 71. That is, as shown in Fig. 4, the rotor core 31 can not only pass the magnetic flux M1 in the radial direction to rotate the rotor 3, but also pass the magnetic fluxes M63, M66 in the axial direction to ensure the energy storage function of the reactor. The direction in which the magnetic fluxes M63, M66 flow is approximately perpendicular to the direction in which the magnetic flux M1 flows.

[0033] The rotor cores and stator cores of conventional radial gap motors often have a structure in which electromagnetic steel sheets or amorphous foils that extend in the radial direction are laminated in the axial direction. Due to this laminated structure, conventional rotor cores and stator cores are limited to forming a two-dimensional magnetic circuit that only allows magnetic flux to flow mainly in the radial direction.

[0034] In contrast, the rotor core 31 of the present embodiment can form a three-dimensional magnetic circuit that can not only pass magnetic flux M1 in the radial direction to rotate the rotor 3, but also pass magnetic fluxes M63, M66 in the axial direction to ensure the energy storage function of the reactor 6.

[0035] Fig. 5 is a diagram (part 1) showing a magnetic circuit formed by each core of the rotor 3, stator 4, and reactor 6 shown in Fig. 1. In Fig. 5, only the axial direction component of the magnetic resistance of the rotor core 31 and the stator core 41 is shown, and the radial direction component and the circumferential direction component of the magnetic resistance are omitted. Fig. 6 is a diagram (part 2) showing a magnetic circuit formed by each core of the rotor 3, stator 4, and reactor 6 shown in Fig. 1. In Fig. 6, only the radial direction component of the magnetic resistance of the rotor core 31 and the stator core 41 is shown, and the axial direction component and the circumferential direction component of the magnetic resistance are omitted.

[0036] In Fig. 5 and Fig. 6, a code combining the alphabet letter "R" and a number corresponds to the magnetic resistance of the portion indicated by the number. For example, R611 corresponds to the magnetic resistance of the ring portion 611. In Fig. 5, a broken line extending in the axial direction indicates a magnetic path extending in the axial direction formed in the rotor core 31. The magnetic path indicated by this broken line is a magnetic path for the magnetic flux generated in one reactor core 61 to pass through the rotor core 31 and flow into the other reactor core 71. In Fig. 6, the magnetic resistance "R31+R41+R5" formed in the magnetic path extending radially in the radial direction indicates a magnetic resistance obtained by combining the radial component of the magnetic resistance of the rotor core 31, the radial component of the magnetic resistance of the stator core 41, and the radial component of the magnetic resistance of the gap 5. The magnetic path extending radially in the radial direction and including the magnetic resistance (R31+R41+R5) is a magnetic path for causing the magnetic flux M1 to flow in the radial direction in order to drive the rotor 3 to rotate.

[0037] In this way, the rotor core 31 formed from a magnetic material having magnetic isotropy forms a three-dimensional magnetic circuit that allows magnetic flux to flow at least in the radial direction and the axial direction. As a result, in the motor 1 of this embodiment, a part of the rotor core 31 can be used as the core of the reactor 6, so that the weight and cost of the core of the reactor 6 can be reduced. In addition, in the motor 1 of this embodiment, the cooling structure of the reactor 6 can be integrated with the cooling structure of the rotor 3 and the stator 4, so that the weight and cost of the cooling structure of the motor 1 can be reduced. Moreover, since the rotor core 31 of this embodiment can form a three-dimensional magnetic circuit as described above, the design freedom of the magnetic circuit is improved, so that a magnetic circuit that can suppress interference between the magnetic flux M1 that rotates the rotor 3 and the magnetic fluxes M63, M66 that are generated in the reactor 6 and pass through the rotor core 31 can be easily formed. Therefore, in the motor 1 of this embodiment, the weight and cost of the core of the reactor 6 and the weight and cost of the cooling structure of the motor 1 can be reduced without impairing the functions of the motor 1 and the reactor 6. Therefore, the motor 1 of this embodiment can dramatically reduce weight and cost.

[0038] Furthermore, in this embodiment, for example, a pair of reactor coils 62, 63 are wound around the ring portion 611, and the winding directions of the pair of reactor coils 62, 63 are opposite to each other. Similarly to the pair of reactor coils 62, 63, the winding directions of the pair of reactor coils 72, 73 wound around the ring portion 711 are also opposite to each other.

[0039] As a result, each of the pair of reactor cores 61, 71 can easily merge, for example, a magnetic flux M61 generated in the ring portion 611 when one of the reactor coils 62 is energized and a magnetic flux M62 generated in the ring portion 611 when the other of the reactor coils 63 is energized toward a specific protruding portion 613, simply by winding the reactor coils 62, 63, without complicating the electric circuit of the converter. The magnetic flux M63 merged at the specific protruding portion 613 flows from one of the reactor cores 61 having this protruding portion 613, through the rotor core 31, to the protruding portion 713 of the other of the reactor cores 71. Therefore, the rotor core 31 of this embodiment can easily form a closed magnetic path through which the magnetic fluxes M63, M66 pass between one of the reactor cores 61 and the other of the reactor cores 71. Therefore, the motor 1 of this embodiment can easily reduce the weight and cost of the core of the reactor 6 and the weight and cost of the cooling structure of the motor 1. Therefore, the motor 1 of this embodiment can dramatically and easily achieve weight and cost reduction.

[0040] Furthermore, in this embodiment, the magnetic material having magnetic isotropy used to form the rotor core 31 is soft magnetic metal powder that is coated with an insulating material.

[0041] This improves the degree of freedom in the shape of the rotor core 31, so that the rotor core 31 of this embodiment can more easily form the above-mentioned three-dimensional magnetic circuit. Therefore, the motor 1 of this embodiment can more easily reduce the weight and cost of the core of the reactor 6 and the weight and cost of the cooling structure of the motor 1. Therefore, the motor 1 of this embodiment can dramatically and easily achieve weight and cost reduction.

[0042] As described above, the pair of reactor cores 61, 71 are disposed to face both end faces 313, 314 of the rotor core 31 in the axial direction. As a more preferable embodiment, the pair of reactor cores 61, 71 may be disposed to face both end faces 313, 314 of the main portion 312 of the rotor core 31. In particular, the protruding portions 612, 613 of the reactor core 61 and the protruding portions 712, 713 of the reactor core 71 may be disposed to face both end faces 313, 314 on the radially inner side (the inner peripheral portion of the rotor core 31) of the main portion 312. As a result, the rotor core 31 of this embodiment can reliably form a magnetic circuit that can suppress interference between the magnetic flux M1 that rotates the rotor 3 and the magnetic fluxes M63, M66 that are generated in the reactor 6 and pass through the rotor core 31. Therefore, the motor 1 of this embodiment can reduce the weight and cost of the core of the reactor 6 and the weight and cost of the cooling structure of the motor 1 without compromising the functions of the motor 1 and the reactor 6.

[0043] As described above, for example, the pair of reactor coils 62, 63 are wound around the ring portion 611, and the winding directions of the pair of reactor coils 62, 63 are opposite to each other. However, the winding directions of the pair of reactor coils 62, 63 may be the same to each other. In this case, currents having polarities opposite to each other are supplied to the reactor coils 62 and the reactor coils 63. As a result, for example, the reactor core 61 can merge the magnetic flux M61 generated in the ring portion 611 when one of the reactor coils 62 is energized and the magnetic flux M62 generated in the ring portion 611 when the other reactor coil 63 is energized toward, for example, the protruding portion 613.

[0044] FIG. 7 is a diagram showing an electric circuit for driving the radial gap motor 1 shown in FIG.

[0045] The electric circuit that drives the motor 1 has a converter 81 and an inverter 82. The converter 81 is an electric circuit that is provided between the inverter 82 and the battery of the electric vehicle, which is a DC power source, and that boosts the battery voltage Vdc. The converter 81 has a reactor 6, a transistor Tr, a diode D, and a capacitor C. The converter 81 charges the capacitor C via the diode D and boosts the voltage by storing and releasing energy in the reactor 6 through the switching operation of the transistor Tr.

[0046] The inverter 82 is an electric circuit that supplies three-phase AC current to the stator coil 42 of the motor 1. The inverter 82 has three legs in which upper arm transistors Tr1 to Tr3 connected to the positive electrode side of the battery and lower arm transistors Tr4 to Tr6 connected to the negative electrode side of the battery are connected in series. Output terminals for three-phase AC voltages of U phase, V phase, and W phase are provided at the connection points of the upper and lower arms included in each of the three legs of the inverter 82. The inverter 82 converts the DC voltage boosted by the converter 81 into AC voltage by switching operations of the transistors Tr1 to Tr6, and supplies the three-phase AC current to the stator coil 42 of the motor 1. As a result, the stator coil 42 can generate a rotating magnetic field and rotate the rotor 3.

[0047] [Embodiment 2] The radial gap motor 1 of the second embodiment will be described with reference to Figures 8 to 10. In the radial gap motor 1 of the second embodiment, the description of the same configuration and operation as in the first embodiment will be omitted.

[0048] Fig. 8 is a schematic cross-sectional view of the radial gap motor 1 of the embodiment 2. Fig. 8 corresponds to Fig. 4. Fig. 9 is a diagram (part 1) showing a magnetic circuit formed by each core of the rotor 3, the stator 4, and the reactor 6 shown in Fig. 8. Fig. 10 is a diagram (part 2) showing a magnetic circuit formed by each core of the rotor 3, the stator 4, and the reactor 6 shown in Fig. 8. Figs. 9 and 10 correspond to Figs. 5 and 6, respectively.

[0049] In the motor 1 of the second embodiment, the stator core 41 may be made of a magnetic material having magnetic isotropy. The pair of reactor cores 61, 71 of the second embodiment may be disposed opposite both end faces 414, 415 of the stator core 41 in the axial direction, respectively.

[0050] In the second embodiment, each of the pair of reactor cores 61 and 71 may have a plurality of pairs of protruding portions. For example, each of the pair of reactor cores 61 and 71 may have three pairs of protruding portions. Figures 9 and 10 show that the reactor core 61 has a pair of protruding portions having magnetic resistances R614 and R615, a pair of protruding portions having magnetic resistances R616 and R617, and a pair of protruding portions having magnetic resistances R618 and R619. Similarly, Figures 9 and 10 show that the reactor core 71 has a pair of protruding portions having magnetic resistances R714 and R715, a pair of protruding portions having magnetic resistances R716 and R717, and a pair of protruding portions having magnetic resistances R718 and R719.

[0051] The stator core 41 of the second embodiment, in cooperation with one reactor core 61 and the other reactor core 71, can form a closed magnetic circuit that passes the magnetic fluxes M63, M66 in the axial direction, similar to the rotor core 31 of the first embodiment. That is, the stator core 41 of the second embodiment can form a three-dimensional magnetic circuit that can pass the magnetic fluxes M63, M66 in the axial direction as well as the magnetic fluxes M1 in the radial direction as well as the magnetic fluxes M1 in the axial direction as well as the magnetic fluxes M1 in the radial direction as well as the magnetic fluxes M63, M66 in the axial direction as well. As a result, the motor 1 of the second embodiment can reduce the weight and cost of the core of the reactor 6 and the weight and cost of the cooling structure of the motor 1 as well as the first embodiment. Therefore, the motor 1 of the second embodiment can dramatically reduce the weight and cost as well as the first embodiment.

[0052] The pair of reactor cores 61, 71 of the second embodiment may be disposed to face both end faces 414, 415 of the yoke 413 of the stator core 41. In particular, the protruding portion of the reactor core 61 and the protruding portion of the reactor core 71 may be disposed to face both end faces 414, 415 of the yoke 413. This allows the stator core 41 of the second embodiment to reliably form a magnetic circuit capable of suppressing interference between the magnetic flux M1 that rotates the rotor 3 and the magnetic fluxes M63, M66 that are generated in the reactor 6 and pass through the rotor core 31. Therefore, the motor 1 of the second embodiment can reduce the weight and cost of the core of the reactor 6 and the weight and cost of the cooling structure of the motor 1 without reliably impairing the functions of the motor 1 and the reactor 6.

[0053] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention described in the claims. In the present invention, the configuration of one embodiment can be added to the configuration of another embodiment, the configuration of one embodiment can be replaced with the configuration of another embodiment, or a part of the configuration of one embodiment can be deleted. [Explanation of symbols]

[0054] 1...motor, 2...rotating shaft, 3...rotor, 31...rotor core, 313...one end surface, 314...other end surface, 4...stator, 41...stator core, 414...one end surface, 415...other end surface, 42...stator coil, 6...reactor, 61...reactor core, 611...ring portion, 612, 613...projection portion, 62, 63...reactor coil, 71...reactor core, 711...ring portion, 712, 713...projection portion, 72, 73...reactor coil, z...axial direction, θ...circumferential direction, r...radial direction

Claims

1. A radial gap motor having a rotor and a stator, The radial gap motor further includes a reactor, the rotor has a rotor core that rotates in a circumferential direction of a rotation shaft of the radial gap motor, The stator includes a stator core and a stator coil wound around the stator core. At least one of the rotor core and the stator core is made of a magnetic material having magnetic isotropy, the reactor includes a pair of reactor cores arranged to face each other on both end surfaces of the one motor core in an axial direction of the rotating shaft, and a reactor coil wound around each of the pair of reactor cores, Each of the pair of reactor cores has a ring portion around which the reactor coil is wound and extends in the circumferential direction, and a pair of protruding portions protruding from a part of the ring portion toward the end surface of one of the motor cores and formed opposite to each other with the rotating shaft therebetween, one protruding portion of one reactor core and one protruding portion of the other reactor core are disposed opposite to each other through the one motor core, and the other protruding portion of the one reactor core and the other protruding portion of the other reactor core are disposed opposite to each other through the one motor core, The pair of reactor cores and the reactor coil are provided such that a magnetic flux generated in the ring portion of the one reactor core when the reactor coil is energized flows from the one protruding portion of the one reactor core through the one motor core, into the one protruding portion of the other reactor core, passes through the ring portion of the other reactor core, and flows from the other protruding portion of the other reactor core through the one motor core into the other protruding portion of the one reactor core. A radial gap motor comprising:

2. A pair of the reactor coils are wound around the ring portion, The winding directions of the pair of reactor coils are opposite to each other.

2. The radial gap motor according to claim 1, wherein the rotor is a rotor having a first end and a second end.

3. The magnetic material is a soft magnetic metal powder with an insulating coating.

3. The radial gap motor according to claim 1, wherein the rotor is a rotor having a first end and a second end.

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