Multilayer rotary bobbin and transformer

Abstract

Provided are: a multilayer rotary bobbin capable of sufficiently suppressing partial discharge between coils while improving the workability of winding work; and a transformer using the same. The multilayer rotary bobbin 20 has a multilayer structure in which a plurality of cylindrical parts 21-24 having different diameters are connected in a radial direction, is rotatably provided on a magnetic core 10 as a member to be attached, and is configured to be capable of forming a plurality of coils 101, 201, 102, 202 by winding a conductive wire around the respective cylindrical parts 21-24. A transformer 1 comprises: an annular magnetic core 10 having a linear part 10A; the multilayer rotary bobbin 20 having the multilayer structure in which the plurality of cylindrical parts 21-24 having different diameters are connected in the radial direction, and which is rotatably provided to the linear part 10A; and the plurality of coils 101, 201, 102, 202 formed by winding a conductive wire around the respective cylindrical parts 21-24. Spaces LA having a width of 2 mm or more along the radial direction of the multilayer rotary bobbin 20 are formed between the coils 101, 201, 102 and the cylindrical parts 22-24 on the outer side in the radial direction.

Description

Multilayer rotating bobbin and transformer

[0001] The present invention relates to a multi-layer rotating bobbin and a transformer using the same.

[0002] Power supplies with an output exceeding 1 kW, such as switching power supplies and isolated inverters, are typically driven at frequencies between approximately 10 kHz and 80 kHz for efficiency reasons. Mn-Zn ferrite has generally been used as the magnetic core material for transformers used in power supplies driven at such high frequencies. In recent years, soft magnetic alloy materials, such as amorphous materials with high saturation magnetic flux density and nanocrystalline materials, have also been used as transformer core materials in order to achieve miniaturization. Conventional transformers are constructed by butting together a pair of U- or E-shaped magnetic cores (cut cores) within a coilform formed by winding a conductor around a bobbin in advance. The pair of magnetic cores are typically butted together to form a square-shaped, racetrack-shaped, or sun-shaped magnetic path overall.

[0003] However, in the above-described conventional transformer, a small gap occurs between the pair of butted magnetic cores, and this gap causes loss due to leakage flux. In particular, when a magnetic core formed from a soft magnetic alloy ribbon with low resistivity is used, loss due to leakage flux caused by the gap increases. Therefore, in the above-described conventional transformer, especially when a magnetic core formed from a soft magnetic alloy ribbon is used, it is not possible to sufficiently increase the operating magnetic flux density, and it is difficult to say that the design fully utilizes the properties of the soft magnetic alloy material.

[0004] On the other hand, there are transformers, such as toroidal transformers, that use uncut metallic magnetic materials as their magnetic cores. Using uncut metallic magnetic materials as their magnetic cores can suppress the loss due to leakage flux and achieve good magnetic properties. However, with toroidal transformers, it is not possible to attach a bobbin with a pre-formed coil to the magnetic core, so the coil must be wound manually, resulting in low productivity and large variations in characteristics.

[0005] In response to this, for example, Patent Document 1 discloses a technique for efficiently performing winding work. In Patent Document 1, a bobbin with a gear is attached to an uncut magnetic core (hereinafter also referred to as an uncut magnetic core) that forms a closed magnetic circuit in the shape of a square, and the winding work (i.e., the work of winding a conductor around the bobbin to form a coil) is performed while rotating the bobbin using the gear, thereby making it possible to easily perform the winding work.

[0006] Patent Document 2 discloses a transformer including an uncut magnetic core formed by winding or laminating a magnetic alloy ribbon and forming a closed magnetic circuit, a protective member covering at least a portion of the magnetic core, a primary coil, a secondary coil, and at least one bobbin provided for winding the conductors that form the primary coil and the secondary coil. In Patent Document 2, a bobbin with gears is used as the bobbin, and the primary coils and secondary coils are alternately arranged around the bobbin, with a sheet-like insulator arranged between the primary coil and the secondary coil.

[0007] According to Patent Documents 1 and 2, a transformer with good characteristics can be realized by using an uncut magnetic core, and the use of a bobbin with a gear facilitates the winding work when forming a coil.

[0008] Japanese Utility Model Application Publication No. 4-85714 Japanese Patent No. 5861805

[0009] Transformers have a wide variety of uses, but some applications require a high rated capacity, such as 100 kVA, because a high voltage is applied to the primary and secondary coils. Transformers with such high rated capacity require adequate measures to prevent partial discharges between live parts and between live parts and the neutral point (ground).

[0010] However, although the above-mentioned Patent Documents 1 and 2 can improve the workability of the winding work, there is a problem in that it is not easy to take sufficient measures against partial discharge between the coils.

[0011] Therefore, an object of the present invention is to provide a multi-layer rotating bobbin that can sufficiently suppress partial discharge between coils while improving the workability of winding work. Another object of the present invention is to provide a multi-layer rotating bobbin transformer that can sufficiently suppress partial discharge between coils while improving the workability of winding work.

[0012] In order to solve the above-mentioned problems, one aspect of the present invention provides a multi-layer rotating bobbin having a multi-layer structure in which multiple cylindrical portions of different diameters are connected radially, which is rotatably mounted on a member to be attached, and which is configured so that multiple coils can be formed by winding a conductive wire around each of the multiple cylindrical portions. Furthermore, the cylindrical portion may be constructed by combining a plurality of divided pieces, and may have a first cylindrical portion which is the cylindrical portion with the smallest diameter, and a second cylindrical portion which is the cylindrical portion connected to the first cylindrical portion, and the first cylindrical portion may have a gear portion for rotating the first cylindrical portion by an external driving force, and at least four flange portions formed and spaced apart in the axial direction, and the four flange portions may divide the outer peripheral surface of the first cylindrical portion into at least three regions, namely a first region, a second region, and a third region, from one side to the other in the axial direction, and the second region may have a first coil forming portion for forming a first coil, and the second cylindrical portion may be connected to at least two of the flange portions of the first cylindrical portion, and may have at least a pair of flange portions, and may have a second coil forming portion for forming a second coil between the pair of flange portions of the second cylindrical portion.

[0013] Furthermore, in another aspect of the present invention, in order to solve the above-mentioned problems, there is provided a transformer comprising: a ring-shaped magnetic core having a straight portion; a bobbin having a multilayer structure in which a plurality of cylindrical portions of different diameters are connected in the radial direction and rotatably provided on the straight portion; and a plurality of coils formed by winding a conductor around each of the plurality of cylindrical portions, wherein a space having a width of 2 mm or more along the radial direction of the bobbin is formed between the coil and the cylindrical portion located radially outside the coil. Furthermore, the bobbin is a multilayer rotary bobbin, and has a first cylindrical portion which is the cylindrical portion of the smallest diameter arranged to surround the straight portion of the magnetic core, and a second cylindrical portion which is the cylindrical portion connected to the first cylindrical portion, wherein the cylindrical portion is formed by combining a plurality of divided pieces, and the first cylindrical portion has a gear portion for rotating the bobbin by an external driving force and at least four flange portions formed spaced apart in the axial direction, and the four flange portions define a first region, a second region, and a third region from one side of the axial direction to the other side of the axial direction. The bobbin may be partitioned into at least three regions, a first region, a second region, and a third region, and the second region may include a first coil formed by winding a conductor around the first cylindrical portion while rotating it, the second cylindrical portion may be connected to at least two of the flange portions of the first cylindrical portion and may have at least a pair of flange portions, and a second coil may be formed between the pair of flange portions of the second cylindrical portion by winding a conductor around the second cylindrical portion while rotating it, and a space having a width of 2 mm or more along the radial direction of the bobbin may be formed between the first coil and the second coil.

[0014] According to the present invention, it is possible to realize a multi-layer rotary bobbin that can sufficiently suppress partial discharge between coils while improving the workability of winding work. Also, according to the present invention, it is possible to realize a transformer that can sufficiently suppress partial discharge between coils while improving the workability of winding work.

[0015] FIG. 1 is a front view of a transformer using a multi-layer rotary bobbin according to one embodiment of the present invention. FIG. 2 is an exploded perspective view of the multi-layer rotary bobbin and a perspective view of the magnetic core. FIG. 3 is a perspective view of the multi-layer rotary bobbin. FIG. 4 is a plan view of the first cylindrical portion. FIG. 5 is a perspective view of the edge cover. FIG. 6 is a plan view of the second cylindrical portion. FIG. 7 is a cross-sectional view showing the coil arrangement. FIG. 8 is a cross-sectional view showing a modified coil arrangement. FIG. 9 is an equivalent circuit diagram of the transformer. FIG. 10 is a front view of the transformer provided with a support frame. FIG. 11 is a cross-sectional view of the coil, bobbin, and magnetic core when a spacer material is attached. FIG. 12A is a plan view of one end surface of the multi-layer rotary bobbin. FIG. 12B is a plan view of the other end surface of the multi-layer rotary bobbin. FIG. 13 is a plan view of the transformer when the ends of the coil are connected to terminals.

[0016] [Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0017] (Overall Configuration of Transformer 1) Fig. 1 is a front view of a transformer 1 using a multi-layer rotating bobbin 20 according to this embodiment. Fig. 2 is an exploded perspective view of the multi-layer rotating bobbin 20 used in the transformer 1 of Fig. 1 and a perspective view of a magnetic core 10.

[0018] As shown in FIGS. 1 and 2 , the transformer 1 includes an annular magnetic core 10 and a pair of multilayer rotating bobbins 20 (hereinafter simply referred to as bobbins 20) according to the present embodiment. The transformer 1 is used in power supply devices such as switching power supplies and insulated inverters. As will be described in detail later, the transformer 1 using the multilayer rotating bobbin 20 according to the present embodiment is suitable as a high-power transformer because it can sufficiently suppress partial discharge between the primary coil and the secondary coil. Specifically, the transformer 1 using the multilayer rotating bobbin 20 according to the present embodiment can be used as a transformer with a high rated capacity, for example, of 50 kVA or more. Note that, because larger magnetic cores 10 and bobbins 20 can accommodate higher power, the upper limit of the power that can be applied to the transformer 1 is not particularly limited. For example, the transformer 1 can have a very high rated capacity, such as 500 kVA or 1000 kVA.

[0019] The transformer 1 can be suitably used as a high-frequency transformer with a frequency of, for example, 2 kHz or more. Although there is no particular upper limit to the frequency, a frequency of about 50 kHz or less is practical.

[0020] (Magnetic Core 10) The magnetic core 10 is preferably made of an uncut metallic magnetic material, i.e., an uncut magnetic core. Although a cut magnetic core (split magnetic core, cut core) can also be used as the magnetic core 10, in this case, when the split magnetic cores 10 are butted together to form a closed magnetic circuit, it is difficult to completely eliminate the magnetic gap at the butt joint between the split magnetic cores, and a small magnetic gap occurs in part of the magnetic circuit. By using an uncut magnetic core 10, such a magnetic gap does not occur, thereby improving the magnetic characteristics of the magnetic core 10. With an uncut magnetic core, it is not possible to attach the bobbin 20 to the magnetic core 10 after winding a conductor around the bobbin 20 to form a coil in advance. Therefore, in this embodiment, a multilayered rotating bobbin (multilayer rotating bobbin) 20 is used to facilitate the winding process. This point will be described in detail later.

[0021] The magnetic core 10 is preferably formed by winding a nanocrystalline alloy ribbon. Alternatively, the magnetic core 10 may be formed by stacking nanocrystalline alloy ribbons. The nanocrystalline alloy ribbon used in the magnetic core 10 has a thickness of 20 μm or less, more preferably 14 μm or less, and even more preferably 12 μm or less. The lower limit of the thickness of the nanocrystalline alloy ribbon is not particularly limited, and may be, for example, 8 μm, 9 μm, or 10 μm.

[0022] When the transformer 1 is used as a high-frequency transformer, a skin effect occurs in the magnetic core 10. Therefore, when the transformer 1 is used as a high-frequency transformer, it is preferable to configure the magnetic core 10 using a nanocrystalline alloy ribbon having a thickness of 20 μm or less, preferably 14 μm or less, and more preferably 12 μm or less.

[0023] In this embodiment, magnetic core 10 is formed in a substantially rectangular ring shape (a rectangle with rounded corners). Magnetic core 10 has a pair of straight portions 10A for attaching a pair of bobbins 20. In this embodiment, straight portions 10A correspond to the long sides of magnetic core 10 formed in a rectangular ring shape.

[0024] (Bobbin 20) The bobbin 20 is a member for holding a coil. The bobbin 20 according to this embodiment is a "multi-layer rotary bobbin." Here, "rotary bobbin" refers to a bobbin 20 that is rotatable after being placed on the magnetic core 10. The "multi-layer rotary bobbin" refers to a rotary bobbin with a multi-layer structure in which a plurality of cylindrical portions 21 to 24 with different diameters are connected in the radial direction. The number of layers of the bobbin 20 may be two or more, preferably three or more, and more preferably four or more. In this embodiment, a multi-layer rotary bobbin with a four-layer structure is used as the bobbin 20.

[0025] 2 and 3, the bobbin 20 has a four-layer structure in which four cylindrical portions 21 to 24 of different diameters are connected in the radial direction. Of the cylindrical portions 21 to 24, the one located radially innermost is referred to as the first cylindrical portion 21, the one located radially outward of the first cylindrical portion 21 is referred to as the second cylindrical portion 22, the one located radially outward of the second cylindrical portion 22 is referred to as the third cylindrical portion 23, and the one located radially outward of the third cylindrical portion 23, i.e., the one located radially outermost, is referred to as the fourth cylindrical portion 24. Each of the cylindrical portions 21 to 24 has a two-piece configuration divided into two approximately equal parts in the circumferential direction, and has a structure in which a pair of divided pieces are combined.

[0026] (First cylindrical portion 21) The first cylindrical portion 21 is the smallest diameter cylindrical portion located in the first layer (the innermost radial layer) of the cylindrical portions 21 to 24. The first cylindrical portion 21 is formed by butting (combining) a pair of divided pieces 21A and 21B together. The butted portions of the pair of divided pieces 21A and 21B have a fitting structure. A plan view of the divided piece 21A is shown in FIG. 4.

[0027] The first cylindrical portion 21 has gear portions 31 on both ends in the axial direction. The gear portions 31 are formed in a gear-like shape. Note that the gear shape is omitted in FIGS. 2 to 4 . Four flange portions 41 to 44 are formed closer to the center in the axial direction (the direction along the rotation axis of the bobbin 20, the left-right direction in FIG. 4 ) than the gear portion 31. These four flange portions 41 to 44 divide the outer peripheral surface of the first cylindrical portion 21 into three regions 61 to 63. Hereinafter, it will be assumed that the first flange portion 41, the second flange portion 42, the third flange portion 43, and the fourth flange portion 44 are formed from left to right in FIG. 4 . Furthermore, the area of ​​the outer surface of the first cylindrical portion 21 surrounded by the flange portion 41 and the flange portion 42 is referred to as the first area 61, the area surrounded by the second flange portion 42 and the third flange portion 43 is referred to as the second area 62, and the area surrounded by the third flange portion 43 and the fourth flange portion 44 is referred to as the third area 63.

[0028] The flanges 41 to 44 each have a notch 51. A plurality of notches 51 are formed in the circumferential direction of each flange 41 to 44. The notches 51 do not have to be notched, and may be holes that pass through the flanges 41 to 44 in the axial direction. The notches 51 are used to pass conductors, as will be described in detail later.

[0029] The first cylindrical portion 21 is formed in a hollow cylindrical shape, and the straight portion 10A of the magnetic core 10 passes through the hollow portion 21C. In other words, the first cylindrical portion 21 is arranged so as to surround the periphery of the straight portion 10A of the magnetic core 10. The first cylindrical portion 21 is then able to rotate in the circumferential direction while being arranged on the straight portion 10A of the magnetic core 10.

[0030] In the first cylindrical portion 21, a first coil 101 (see FIG. 7 ) is formed in a second region 62 located at the axial center. That is, the first cylindrical portion 21 has a first coil forming portion in the second region 62 for forming the first coil 101. When winding a conductor around this second region 62, a driving force is transmitted to the gear portion 31 of the first cylindrical portion 21, and the conductor winding operation (winding operation) is performed while rotating the first cylindrical portion 21.

[0031] During the winding process, the winding start end must be processed. A certain amount of excess wire is required at the winding start end for connecting the first coil 101 to other components, etc. However, if the winding process is performed with this excess wire at the winding start end extended, it may cause inconveniences, such as hindering the rotation of the bobbin 20. In this embodiment, the first region 61 (or the third region 63) is used as a processing region for the winding start end, and the excess wire at the winding start end is wound around this first region 61. The wire can be transferred between the first region 61 and the second region 62 through the notch 51 in the second flange 42. Similarly, the third region 63 (or the first region 61) can be used as a processing region for the winding end. For example, winding the winding end around the third region 63 makes it possible to process the excess wire at the winding end. The conductor wire can be passed between the second region 62 and the third region 63 through the notch 51 of the third flange 43. Note that the flanges 42 and 43 are provided with a plurality of notches 51, and the notch 51 to be used can be selected as appropriate.

[0032] To prevent damage to the magnetic core 10 due to friction with the first cylindrical portion 21 when the first cylindrical portion 21 is rotated, it is preferable to place edge covers 81 (see FIG. 5 ) between the first cylindrical portion 21 and the magnetic core 10. The edge covers 81 are placed at each of the four corners of the linear portion 10A of the magnetic core 10. The edge covers 81 may be made of, for example, PTFE (polytetrafluoroethylene). The use of the edge covers 81 protects the corners of the magnetic core 10 and reduces the load applied to the corners of the magnetic core 10 when the first cylindrical portion 21 is rotated. This prevents deformation, chipping, breakage, and the like of the magnetic core 10. It is also preferable to place edge covers 81 when forming the second coil 201, the third coil 102, and the fourth coil 202.

[0033] (Second cylindrical portion 22) The second cylindrical portion 22 is a cylindrical portion in the second layer (second from the radially inner side) and is connected to the radially outer side of the first cylindrical portion 21. The second cylindrical portion 22 is formed by butting (combining) a pair of divided pieces 22A, 22B together. The second cylindrical portion 22 is connected to the radially outer ends of at least two of the flange portions 41 to 44 of the first cylindrical portion 21. In the present embodiment, the second cylindrical portion 22 is connected to the radially outer ends of the second flange portion 42 and the third flange portion 43, and is provided so as to cover the peripheries of the second flange portion 42, the second region 62, and the third flange portion 43 of the first cylindrical portion 21.

[0034] Fig. 6 is a plan view of a segment 22A of the second cylindrical portion 22. As shown in Fig. 6, the second cylindrical portion 22 has flanges 71, 72 formed at both axial ends thereof. A second coil 201 is formed by winding a conductor between these flanges 71, 72 (see Fig. 7). That is, the second cylindrical portion 22 has a second coil forming portion between the flanges 71, 72 for forming the second coil 201. The flanges 71, 72 have cutouts 51 formed therein for passing the conductor through.

[0035] The second cylindrical portion 22 does not cover the first region 61 or the third region 63 of the first cylindrical portion 21. As a result, when winding a conductor wire around the second cylindrical portion 22, the first region 61 (or the third region 63) of the first cylindrical portion 21 can be used as a processing region for the winding start end. For example, the winding start end may be processed by winding the excess conductor wire at the winding start end around the first region 61 of the first cylindrical portion 21. After processing the winding start end, a driving force is transmitted to the gear portion 31 of the first cylindrical portion 21 to rotate the second cylindrical portion 22 together with the first cylindrical portion 21, and the conductor wire is wound around the second cylindrical portion 22, thereby forming the second coil 201. The conductor wire can be transferred between the first region 61 and the second cylindrical portion 22 through the notch 51 of the flange portion 71. Similarly, the third region 61 (or the first region 61) of the first cylindrical portion 21 can be used as a processing region for the winding end of the second coil 201. For example, the winding end may be processed by winding the excess length of the conductor wire around the third region 63. The conductor wire can be passed between the second cylindrical portion 22 and the third region 63 through the notch 51 of the flange 72. Note that the flanges 71, 72 are provided with a plurality of notches 51, and the notch 51 to be used can be selected as appropriate.

[0036] (Third Cylindrical Portion 23) The third cylindrical portion 23 is a cylindrical portion in the third layer (third from the radially inner side) and is connected to the radially outer side of the second cylindrical portion 22. The third cylindrical portion 23 is formed by butting (combining) a pair of split pieces 23A, 23B together. The third cylindrical portion 23 is connected to the radially outer ends of the two flanges 71, 72 of the second cylindrical portion 22 and is provided to cover the radially outer side of the entire second cylindrical portion 22. The third cylindrical portion 23 has flanges 73, 74 formed at both axial ends thereof. A third coil 102 is formed by winding a conductor between these flanges 73, 74 (see FIG. 7 ). That is, the third cylindrical portion 23 has a third coil forming portion between the flanges 73, 74 for forming the third coil 102. The flanges 73, 74 have cutouts 51 formed therein for passing the conductor through.

[0037] Like the second cylindrical portion 22, the third cylindrical portion 23 does not cover the first region 61 or the third region 63 of the first cylindrical portion 21. This allows the first region 61 (or the third region 63) of the first cylindrical portion 21 to be used as a processing region for the winding start end when winding the conductor wire around the third cylindrical portion 23. For example, the winding start end may be processed by winding the excess conductor wire at the winding start end around the first region 61 of the first cylindrical portion 21. After processing the winding start end, a driving force is transmitted to the gear portion 31 of the first cylindrical portion 21 to rotate the third cylindrical portion 23 together with the first cylindrical portion 21 and the second cylindrical portion 22, thereby winding the conductor wire around the third cylindrical portion 23 to form the third coil 102. The conductor wire can be transferred between the first region 61 and the third cylindrical portion 23 through the notch 51 of the flange portion 73. Similarly, the third region 63 (or the first region 61) of the first cylindrical portion 21 can be used as a processing region for the winding end of the third coil 102. For example, the winding end may be processed by winding the excess length of the conductor wire at the winding end around the third region 63. The conductor wire can be transferred between the third cylindrical portion 23 and the third region 63 through the notch 51 in the flange 74. Note that the flanges 73, 74 are provided with a plurality of notches 51, and the notch 51 to be used can be selected as appropriate.

[0038] (Fourth Cylindrical Portion 24) The fourth cylindrical portion 24 is the fourth layer (the outermost cylindrical portion in the radial direction) and is connected to the radially outer side of the third cylindrical portion 23. The fourth cylindrical portion 24 is formed by butting (combining) a pair of split pieces 24A, 24B together. The fourth cylindrical portion 24 is connected to the radially outer ends of the two flange portions 73, 74 of the third cylindrical portion 23 and is provided to cover the radially outer side of the entire third cylindrical portion 23. The fourth cylindrical portion 24 has flange portions 75, 76 formed at both axial ends thereof. A fourth coil 202 is formed by winding a conductor between these flange portions 75, 76 (see FIG. 7 ). That is, the fourth cylindrical portion 24 has a fourth coil forming portion between the flange portions 75, 76 for forming the fourth coil 202. The flange portions 75, 76 have cutout portions 51 formed therein for passing the conductor.

[0039] Like the second cylindrical portion 22 and the third cylindrical portion 23, the fourth cylindrical portion 24 does not cover the first region 61 or the third region 63 of the first cylindrical portion 21. This allows the first region 61 (or the third region 63) of the first cylindrical portion 21 to be used as a processing region for the winding start end when winding a conductor around the fourth cylindrical portion 24. For example, the winding start end may be processed by winding the excess conductor length at the winding start end around the first region 61 of the first cylindrical portion 21. After processing the winding start end, a driving force is transmitted to the gear portion 31 of the first cylindrical portion 21 to rotate the fourth cylindrical portion 24 together with the first to third cylindrical portions 21 to 23, thereby winding the conductor around the fourth cylindrical portion 24 to form the fourth coil 202. The conductor can be transferred between the first region 61 and the fourth cylindrical portion 24 through the notch 51 of the flange 75. Similarly, the third region 63 (or the first region 61) of the first cylindrical portion 21 can be used as a processing region for the winding end of the fourth coil 202. For example, the winding end may be processed by winding the excess conductor wire at the winding end around the third region 63. The conductor wire can be transferred between the fourth cylindrical portion 24 and the third region 63 through the notch 51 in the flange 76. Note that the flanges 75, 76 are provided with a plurality of notches 51, and the notch 51 to be used can be selected as appropriate.

[0040] Whether the processing region for the winding start end is the first region 61 or the third region 63 can be selected as appropriate. Similarly, whether the processing region for the winding end is the first region 61 or the third region 63 can be selected as appropriate. The processing regions for the winding start end and the winding end may be the same region. When winding the excess wire at the winding start end or the winding end into the first region 61 or the third region 63, the winding of the wire can be performed while transmitting a driving force to the gear portion 31 of the first cylindrical portion 21 to rotate the bobbin 20. Furthermore, the processing regions for the winding start end and the winding end and the position of the notch 51 through which the wire passes may be changed depending on whether the target coils 101, 201, 102, and 202 are primary coils or secondary coils.

[0041] (Arrangement of coils 101, 201, 102, 202) Here, the arrangement of the four coils 101, 201, 102, 202 will be described. Fig. 7 is a cross-sectional view showing the arrangement of the coils 101, 201, 102, 202 in this embodiment. As shown in Fig. 7, the first coil 101 is provided between the flanges 42, 43 of the first cylindrical portion 21. Similarly, the second coil 201 is provided between the flanges 71, 72 of the second cylindrical portion 22, the third coil 102 is provided between the flanges 73, 74 of the third cylindrical portion 23, and the fourth coil 202 is provided between the flanges 75, 76 of the fourth cylindrical portion 24.

[0042] In this embodiment, the first coil 101 and the third coil 102 form the primary coil, and the second coil 201 and the fourth coil 202 form the secondary coil. By alternately arranging the primary coils and the secondary coils in this manner, the resistance of the entire coil can be reduced and the coupling between the primary coils and the secondary coils can be improved. Note that, although the bobbin 20 has a four-layer structure in this embodiment, if it has three or more layers, it is preferable to alternately arrange the primary coils and the secondary coils.

[0043] In this embodiment, a space LA is provided between the first coil 101 and the second coil 201, between the second coil 201 and the third coil 102, and between the third coil 102 and the fourth coil 202. More precisely, the space LA is a space (gap or air layer) formed between the first coil 101 and the second cylindrical portion 22, between the second coil 201 and the third cylindrical portion 23, and between the third coil 102 and the fourth cylindrical portion 24. By adjusting the width of this space LA (the width along the radial direction of the bobbin 20) to an appropriate width, partial discharge between the primary coil and the secondary coil can be suppressed. In this embodiment, the width of the space LA is set to 2 mm or more. The width of the space LA is preferably 3 mm or more, and more preferably 4 mm or more.

[0044] In this embodiment, each of the cylindrical portions 21 to 24 of the bobbin 20 has a flange portion 42, 43, 71, 72, 73, 74, 75, and 76, and the width of the space LA can be easily adjusted by adjusting the height of the flange portions 42, 43, 71, 72, 73, and 74 of the first to third cylindrical portions 21 to 23. The width of the space LA is determined by the relationship between the height of each of the coils 101, 201, and 102 and the height of the flange portions 42, 43, 71, 72, 73, and 74.

[0045] In this embodiment, a barrier tape 91 is wound around the outer peripheral surface of the first cylindrical portion 21 (here, the region of the end of the second region 62 on the second flange 42 side), and the winding start position of the first coil 101 is adjusted by adjusting the width of the barrier tape 91 (winding width of the barrier tape 91). Similarly, a barrier tape 92 is wound around the outer peripheral surface of the second cylindrical portion 22 to adjust the winding start position of the second coil 201. A barrier tape 93 is wound around the outer peripheral surface of the third cylindrical portion 23 to adjust the winding start position of the third coil 102. And a barrier tape 94 is wound around the outer peripheral surface of the fourth cylindrical portion 24 to adjust the winding start position of the fourth coil 202. In the example of FIG. 7 , the barrier tapes 91 to 94 are adjusted to the same width.

[0046] In this embodiment, by using barrier tapes 91 to 94, coils 101, 201, 102, and 202 are provided in the central portion of bobbin 20 in the axial direction. This allows the coils 101, 201, 102, and 202 to be spaced apart from magnetic core 10 and support frame 301 (see FIG. 10 ) that supports magnetic core 10. Furthermore, in this embodiment, first region 61 and third region 63 are provided in first cylindrical portion 21, allowing the coils 101, 201, 102, and 202 to be spaced apart from magnetic core 10 and support frame 301 that supports magnetic core 10. In this way, first region 61 and third region 63 are effective not only for treating the winding start and end ends of coils 101, 201, 102, and 202, but also as a measure against partial discharge.

[0047] Furthermore, the provision of the first region 61 and the third region 63 increases the distance between the magnetic core 10 and the support frame 301, thereby improving the workability, for example, when connecting the first coil 101 and the third coil 102, or the second coil 201 and the fourth coil 202, or when routing the winding start and end ends of each coil 101, 201, 102, and 202 to form connection terminals to an external circuit. The axial widths of the first region 61 and the third region 63 (the distance between the first flange 41 and the second flange 42, and the distance between the third flange 43 and the fourth flange 44) are preferably 10 mm or more, more preferably 20 mm or more. The axial widths of the first region 61 and the third region 63 are more preferably 30 mm or more, and even more preferably 40 mm or more.

[0048] In this embodiment, the primary coil and the secondary coil are disposed at the same axial position of the bobbin 20. However, the primary coil and the secondary coil may be disposed with an axial offset. For example, as shown in FIG. 8 , the winding width of the barrier tapes 91 and 93 may be L1, and the winding width of the barrier tapes 92 and 94 may be L1+L2, so that the primary coil and the secondary coil are disposed with an axial offset of L2. By displacing the primary coil and the secondary coil as shown in FIG. 8 , the leakage inductance between the primary coil and the secondary coil can be adjusted. The axial offset L2 between the primary coil and the secondary coil is preferably 20 mm or more and 60 mm or less. Furthermore, although the first coil 101 and the third coil 102 are referred to as primary coils in this example, the first coil 101 and the third coil 102 may also be referred to as secondary coils. In this case, the second coil 201 and the fourth coil 202 are primary coils.

[0049] During operation of the transformer 1, the magnetic core 10 and the coils 101, 201, 102, and 202 may generate heat. In this embodiment, a plurality of notches 51 are formed in the flanges 42, 43, 71, 72, 73, 74, 75, and 76 of the bobbin 20, so that cooling air can be forced to pass through the space LA through these notches 51. This allows the magnetic core 10 and the coils 101, 201, 102, and 202 to be air-cooled, improving the cooling effect.

[0050] (Equivalent Circuit) FIG. 9 is an equivalent circuit diagram of the transformer 1. In FIG. 9, the first coil 101 of one bobbin 20 is designated as A1, the third coil 102 as A3, the second coil 201 as A2, and the fourth coil 202 as A4. Also, in FIG. 9, the first coil 101 of the other bobbin 20 is designated as B1, the third coil 102 as B3, the second coil 201 as B2, and the fourth coil 202 as B4. In the equivalent circuit diagram of FIG. 9, the first coil 101 and the third coil 102, and the second coil 201 and the fourth coil 202 are connected in parallel. Furthermore, the primary coils and the secondary coils of one bobbin 20 and the other bobbin 20 are also connected in parallel. However, the parallel or series connection can be appropriately set. In addition, although a pair of bobbins 20 is used in this embodiment, the present invention is not limited to this. A single bobbin 20 may be arranged on only one straight portion 10A.

[0051] (Support frame 301) In a high-power transformer 1, the magnetic core 10 also becomes large. For example, when a large magnetic core 10 is made of a nanocrystalline alloy ribbon, the weight also becomes heavy, making it difficult to fix the magnetic core 10. In such a case, it is preferable to use a support frame 301 made of a nonmagnetic metal (for example, stainless steel) that supports the magnetic core 10.

[0052] Fig. 10 is a front view of the transformer 1 provided with a support frame 301. In the example of Fig. 10, the support frame 301 has an integral coil base 302. This coil base 302 supports the bobbin 20 on which the coils 101, 201, 102, and 202 are arranged, and holds the coils 101, 201, 102, and 202 so that they do not shift in position relative to the magnetic core 10.

[0053] (Spacer Material 82) As described above, when rotating the bobbin 20, i.e., during the winding operation, it is preferable to place an edge cover 81 (see FIG. 5) between the magnetic core 10 and the bobbin 20. In this embodiment, after the winding operation is completed, the edge cover 81 is removed, and a spacer material 82 is placed at the axial end of the bobbin 20, as shown in FIG. 11. The spacer material 82 is inserted and placed between the magnetic core 10 and the first cylindrical portion 21 of the bobbin 20. The spacer material 82 is placed at both axial ends of the first cylindrical portion 21. By placing the spacer material 82, a space LA is formed between the first coil 101 and the magnetic core 10 (between the straight portion 10A of the magnetic core 10 and the second region 62 of the first cylindrical portion 21). By forming this space LA, partial discharge between the coil (first coil 101) and the magnetic core 10 can be suppressed. The width of the space LA along the radial direction of the bobbin 20 is preferably 2 mm or more. Furthermore, the width of the space LA is preferably 3 mm or more, and more preferably 4 mm or more. The spacer material 82 is preferably made of PTFE.

[0054] (Regarding the notches 51 through which the winding start and winding end are pulled out) Figure 12A is a plan view of one end surface of the bobbin 20, and Figure 12B is a plan view of the other end surface. In this embodiment, the winding start end of the first coil 101 is pulled out axially outward through notch 1H1, and the winding end of the first coil 101 is pulled out axially outward through notch 1H2. The winding start end of the second coil 201 is pulled out axially outward through notch 2H1, and the winding end of the second coil 201 is pulled out axially outward through notch 2H2. The winding start end of the third coil 102 is pulled out axially outward through notch 3H1, and the winding end of the third coil 102 is pulled out axially outward through notch 3H2. The winding start end of the fourth coil 202 is pulled out axially outward through the notch 4H1, and the winding end of the fourth coil 202 is pulled out axially outward through the notch 4H2.

[0055] In the transformer 1, the first coil 101 and the third coil 102 constitute a primary coil, and the second coil 201 and the fourth coil 202 constitute a secondary coil. Therefore, in this embodiment, notches 1H1 and 3H1 through which the winding start ends of the first coil 101 and the third coil 102 constituting the primary coil are pulled out, and notches 2H1 and 4H1 through which the winding start ends of the second coil 201 and the fourth coil 202 constituting the secondary coil are pulled out are positioned 180 degrees apart in the circumferential direction of the bobbin 20. Similarly, notches 1H2 and 3H2 through which the winding end ends of the first coil 101 and the third coil 102 constituting the primary coil are pulled out, and notches 2H2 and 4H2 through which the winding end ends of the second coil 201 and the fourth coil 202 constituting the secondary coil are pulled out are positioned 180 degrees apart in the circumferential direction of the bobbin 20. This makes it possible to further suppress partial discharge between the primary coil and the secondary coil.

[0056] (Connection of Ends of Each Coil 101, 201, 102, 202) Fig. 13 is a diagram showing the connection of the ends of each coil 101, 201, 102, 202. As shown in Fig. 13, the ends (winding start end and winding end) of each coil 101, 201, 102, 202 of the transformer 1 are routed through a protective tube 402 and connected to copper terminals 401. In the example of Fig. 13, the ends of the first coil 101 and the third coil 102 constituting the primary coil are led out on one side of the transformer 1, and the ends of the second coil 201 and the fourth coil 202 constituting the secondary coil are led out on the other side of the transformer 1.

[0057] [Example 1] A wound nanocrystalline alloy ribbon was used as the magnetic core 10. FT-3 material manufactured by Proterial Co., Ltd. was used as the nanocrystalline alloy ribbon. The nanocrystalline alloy ribbon had a thickness of 12 μm and a width of 53 mm. The outer dimensions of the magnetic core 10 were 470 mm × 256 mm, and the inner dimensions were 360 ​​mm × 146 mm. The magnetic core 10 was impregnated with epoxy resin, and stainless steel (SUS304) ribbons were wound around the inner and outer circumferences.

[0058] A first cylindrical portion 21 was disposed on one of the linear portions 10A of the magnetic core 10 so as to surround the linear portion 10A. Urethane resin (PX234HT) manufactured by Sika Corporation was used as the material for the cylindrical portions 21 to 24 of the bobbin 20. Note that PET resin (FR530) manufactured by DuPont Co., Ltd. may also be used as the material for the cylindrical portions 21 to 24.

[0059] Edge covers 81 made of PTFE were placed around the corners of the straight portion 10A, and a conductor was wound around the first cylindrical portion 21 while rotating the first coil 101. The conductor was an 8 mm outer diameter conductor having a conductor formed by twisting together 1,000 metal wires each having an outer diameter of 0.2 mm. Two pairs of these conductors were wound together for nine turns to form the first coil 101 (see FIG. 8 ). More specifically, a barrier tape 91 was wrapped around the second region 62 of the first cylindrical portion 21 in advance to specify the winding start position of the conductor (position L1 from the second flange 42). The winding start end was then guided from the second region 62 to the first region 61 through the notch 51 in the second flange 42, and the winding start end was temporarily wound around the first region 61 to complete the winding start end processing. Thereafter, a driving force was transmitted to the gear portion 31 of the first cylindrical portion 21 to rotate the first cylindrical portion 21, and the conductive wire was wound around the second region 62 to form the first coil 101. The winding end was introduced into the third region 63 through the notch 51 of the third flange 43 and temporarily wound. The widths of the first region 61 and the third region 63 (the distance between the first flange 41 and the second flange 42, and the distance between the third flange 43 and the fourth flange 44) were each 44 mm. As shown in FIGS. 12A and 12B , the winding start end of the first coil 101 was pulled out axially outward through the notch 1H1, and the winding end end of the first coil 101 was pulled out axially outward through the notch 1H2.

[0060] Thereafter, the second cylindrical portion 22 was connected to the flanges 42, 43 of the first cylindrical portion 21 on which the first coil 101 was formed. Then, a barrier tape 92 was wrapped around the second cylindrical portion 22, and a conductor was wound around it to form a second coil 201 between the flanges 71, 72. The second coil 201 had the same configuration as the first coil 101. However, the winding start position of the second coil 201 was shifted axially by L2 from the winding start position of the first coil 101 (see FIG. 8 ). As shown in FIGS. 12A and 12B , the winding start end of the second coil 201 was pulled out axially outward through the notch 2H1, and the winding end of the second coil 201 was pulled out axially outward through the notch 2H2. Then, the winding start end in the first region 61 of the first cylindrical portion 21 and the winding end in the third region 63 were processed.

[0061] Thereafter, the third cylindrical portion 23 was connected to the flanges 71, 72 of the second cylindrical portion 22 on which the second coil 201 was formed. A barrier tape 93 was wrapped around the third cylindrical portion 23, and a conductor was then wound thereon to form a third coil 102 between the flanges 73, 74. The third coil 102 had the same configuration as the first coil 101 and the second coil 201. The winding start position of the third coil 102 was the same as the first coil 101. As shown in FIGS. 12A and 12B , the winding start end of the third coil 102 was pulled out axially outward through the notch 3H1, and the winding end end of the third coil 102 was pulled out axially outward through the notch 3H2. Then, the winding start end in the first region 61 of the first cylindrical portion 21 and the winding end in the third region 63 were processed, respectively.

[0062] Thereafter, the fourth cylindrical portion 24 was connected to the flanges 73, 74 of the third cylindrical portion 23 on which the third coil 102 was formed. A barrier tape 94 was wrapped around the fourth cylindrical portion 24, and a conductor was then wound thereon to form a fourth coil 202 between the flanges 75, 76. The fourth coil 202 had the same configuration as the first coil 101, the second coil 201, and the third coil 102. The winding start position of the fourth coil 202 was the same as that of the second coil 201. As shown in FIGS. 12A and 12B , the winding start end of the fourth coil 202 was pulled out axially outward through the notch 4H1, and the winding end end of the fourth coil 202 was pulled out axially outward through the notch 4H2. Then, the winding start end in the first region 61 of the first cylindrical portion 21 and the winding end in the third region 63 were processed, respectively. The offset L2 between the winding start positions of the primary coil and the secondary coil was set to 30 mm, thereby adjusting the leakage inductance to 4 μH. L1 was set to 40 mm.

[0063] The bobbin 20 is designed to rotate by transmitting a driving force to the gear portion 31 of the first cylindrical portion 21, which facilitates the winding process for forming the coils 101, 201, 102, and 202. Furthermore, the heights of the flanges 42, 43, 71, 72, and 73 of the first cylindrical portion 21, the second cylindrical portion 22, and the third cylindrical portion 23 were adjusted to form spaces LA with a width of 4 mm along the radial direction of the bobbin 20 between the first coil 101 and the second coil 201, between the second coil 201 and the third coil 102, and between the third coil 102 and the fourth coil 202. These spaces LA suppress partial discharge between the primary and secondary coils. These spaces can also be used to cool the magnetic core 10 and each of the coils 101, 201, 102, and 202.

[0064] After forming the coils 101, 201, 102, and 202 on the bobbin 20, the edge cover 81 was removed, and spacer materials 82 made of PTFE were placed on both axial ends of the first cylindrical portion 21. This formed a space LA with a width of 4 mm along the radial direction of the bobbin 20 between the magnetic core 10 and the first coil 101. This space LA makes it possible to suppress partial discharge between the magnetic core 10 and the first coil 101.

[0065] A bobbin 20 was similarly placed on the other straight portion 10A of the magnetic core 10, and coils 101, 201, 102, and 202 were formed. This resulted in the formation of the example transformer 1, a high-frequency transformer with a frequency of 16 kHz and a rated capacity of 400 kVA. Because the magnetic core 10 of the example transformer 1 was large and heavy, support frames 301 made of nonmagnetic metal (SUS304) were placed above and below the magnetic core 10, and the magnetic core 10 was fixed and held to the support frames 301 using bolts and nuts (see FIG. 10 ). Then, as shown in FIG. 13 , the ends (winding start and winding end) of each coil 101, 201, 102, and 202 of the transformer 1 were routed through protective tubes 402 and connected to copper terminals 401. Table 1 shows the characteristic values ​​of the example transformer 1.

[0066]

[0067] According to the transformer 1 of the embodiment, partial discharge between the primary coil and the secondary coil could be sufficiently suppressed. Also, partial discharge between the primary coil or the secondary coil and the magnetic core 10 could be sufficiently suppressed. Furthermore, the primary coil or the secondary coil could be sufficiently separated from the support frame.

[0068] (Functions and effects of the embodiment) As described above, the bobbin 20 according to this embodiment has a multi-layer structure in which multiple cylindrical sections 21 to 24 of different diameters are connected radially, and is rotatably mounted on the member to which it is to be attached (here, the straight section 10A of the magnetic core 10), and is configured so that multiple coils 101, 201, 102, 202 can be formed by winding a conductor around each of the multiple cylindrical sections 21 to 24.

[0069] As a result, while the workability of the winding work is improved by rotating the bobbin 20, by appropriately adjusting the distance between each of the cylindrical portions 21 to 24 (i.e., the width of the space LA along the radial direction of the bobbin 20), it is possible to suppress partial discharge between the coils 101, 201, 103, and 202, and to sufficiently suppress partial discharge between the primary coil and the secondary coil when used in the transformer 1. Therefore, by using the bobbin 20 according to this embodiment in the transformer 1, it is possible to realize a transformer 1 that can sufficiently suppress partial discharge between live parts, even when a high rated capacity is used.

[0070] In addition, in the transformer 1 according to this embodiment, a multi-layer rotating bobbin is used as the bobbin 20, and a space LA having a width of 2 mm or more along the radial direction of the bobbin 20 is formed between the coils 101, 201, 103 and the cylindrical portions 22 to 24 on their outer sides.

[0071] This makes it possible to suppress partial discharges between the coils 101, 201, 103, and 202, and to sufficiently suppress partial discharges between the primary and secondary coils, while improving the workability of the winding work by rotating the bobbin 20. In other words, it is possible to realize a transformer 1 that can sufficiently suppress partial discharges between live parts, even when a high rated capacity is used.

[0072] (Modification) In the above embodiment, after forming the first coil 101, the second cylindrical portion 22 is connected to the first cylindrical portion 21, and the second coil 201 is formed on the second cylindrical portion 22. However, this is not limiting, and for example, the first coil 101 and the second coil 201 may be formed simultaneously. In this case, for example, after processing the winding start end of the first coil 101, the second cylindrical portion 22 may be connected to the first cylindrical portion 21, and the winding start end of the second coil 201 may be processed. Thereafter, a driving force may be transmitted to the gear portion 31 of the first cylindrical portion 21 to rotate the first cylindrical portion 21 and the second cylindrical portion 22, thereby simultaneously forming the first coil 101 and the second coil 201. In this way, when forming the coils 101, 201, 103, and 202, they may be formed one by one, or multiple coils may be formed together.

[0073] In the above embodiment, the bobbin 20 is applied to the transformer 1, but it can also be used for purposes other than the transformer 1.

[0074] (Summary of the embodiment) Next, the technical ideas grasped from the embodiment described above will be described by using the reference numerals and the like in the embodiment. However, the reference numerals and the like in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiment.

[0075] [1] A multi-layer rotary bobbin (20) having a multi-layer structure in which a plurality of cylindrical portions (21-24) of different diameters are connected in the radial direction, and which is rotatably mounted on a member (magnetic core 10) to which it is attached, and which is configured so that a plurality of coils (101, 201, 102, 202) can be formed by winding a conducting wire around each of the plurality of cylindrical portions (21-24).

[0076] [2] A multi-layer structure in which a plurality of cylindrical portions (21 to 24) of different diameters are connected in the radial direction, and the cylindrical portions (21 to 24) are configured by combining a plurality of divided pieces (21A to 24A, 21B to 24B), and the cylindrical portion (21 to 24) has a first cylindrical portion (21) which is the cylindrical portion (21 to 24) with the smallest diameter, and a second cylindrical portion (22) which is the cylindrical portion (21 to 24) connected to the first cylindrical portion (21), and the first cylindrical portion (21) has a gear portion (31) for rotating the first cylindrical portion (21) by an external driving force, and at least four flange portions (41 to 44) formed at a distance in the axial direction, and the four flange portions (41 to 44) The outer peripheral surface of the first cylindrical portion (21) is partitioned from one side to the other in the axial direction into at least three regions, a first region (61), a second region (62), and a third region (63), and the second region (62) has a first coil forming portion for forming a first coil (101), and the second cylindrical portion (22) is connected to at least two of the flange portions (41 to 44) of the first cylindrical portion (21) and has at least a pair of flange portions (71, 72), and has a second coil forming portion for forming a second coil (201) between the pair of flange portions (71, 72) of the second cylindrical portion (22).

[0077] [3] The multilayer rotary bobbin (20) according to [2], further comprising a third cylindrical portion (23) which is one of the cylindrical portions (21 to 24) connected to the second cylindrical portion (22), the third cylindrical portion (23) being connected to at least two of the flange portions (71, 72) of the second cylindrical portion (22) and having at least a pair of flange portions (73, 74), and having a third coil forming portion for forming a third coil (102) between the pair of flange portions (73, 74) of the third cylindrical portion (23).

[0078] [4] The multilayer rotary bobbin (20) according to [3], further comprising a fourth cylindrical portion (24) which is one of the cylindrical portions (21 to 24) connected to the third cylindrical portion (23), the fourth cylindrical portion (24) being connected to at least two of the flange portions (73, 74) of the third cylindrical portion (23) and having at least a pair of flange portions (75, 76), and having a fourth coil forming portion for forming a fourth coil (202) between the pair of flange portions (75, 76) of the fourth cylindrical portion (24).

[0079] [5] The multi-layer rotary bobbin (20) described in [2], wherein the second cylindrical portion (22) is connected to the two flange portions (42, 43) located at both ends of the second region (63) of the first cylindrical portion (21).

[0080] [6] The multi-layer rotary bobbin (20) according to [2], wherein each of the flanges (41 to 44, 71, 72) has a notch (51).

[0081] [7] The multi-layer rotary bobbin (20) according to [2], wherein the width of the first region (61) and the third region (63) along the axial direction is 10 mm or more.

[0082] [8] A transformer (1) comprising: an annular magnetic core (10) having a straight portion (10A); a bobbin (20) having a multilayer structure in which a plurality of cylindrical portions (21 to 24) of different diameters are radially connected; the bobbin (20) rotatably provided on the straight portion (10A); and a plurality of coils (101, 201, 102, 202) formed by winding a conductor around each of the plurality of cylindrical portions (21 to 24), wherein a space (LA) having a width of 2 mm or more along the radial direction of the bobbin (20) is formed between the coils (101, 201, 102) and the cylindrical portions (22 to 24) radially outside thereof.

[0083] [9] A magnetic core (10) having an annular shape and a straight portion (10A), and a bobbin (20) having coils (101, 201, 102, 202) and arranged on the straight portion (10A) of the magnetic core (10), wherein the bobbin (20) is a multi-layer rotary bobbin having a multi-layer structure in which a plurality of cylindrical portions (21 to 24) having different diameters are connected in the radial direction, and the cylindrical portion (21 to 24) having the smallest diameter is arranged to surround the straight portion (10A) of the magnetic core (10). The bobbin (20) has a first cylindrical portion (21) and a second cylindrical portion (22) which is a cylindrical portion (21-24) connected to the first cylindrical portion (21), and the cylindrical portions (21-24) are configured by combining a plurality of divided pieces (21A-24A, 21B-24B), and the first cylindrical portion (21) has a gear portion (31) for rotating the bobbin (20) by an external driving force, and at least four flange portions (41-44) formed at intervals in the axial direction. and the four flanges (41 to 44) divide the outer peripheral surface of the first cylindrical portion (21) into at least three regions, a first region (61), a second region (62), and a third region (63), from one side to the other in the axial direction, and the second region (62) is provided with a first coil (101) formed by winding a conductor around the first cylindrical portion (21) while rotating the first cylindrical portion (21), and the second cylindrical portion (22) is provided with a first coil (101) formed by winding a conductor around the first cylindrical portion (21) while rotating the first cylindrical portion (21). The transformer (1) is connected to the flanges (41 to 44) and has at least a pair of flanges (71, 72), and is provided with a second coil (201) formed by winding a conductor around the second cylindrical portion (22) while rotating the second cylindrical portion (22) between the pair of flanges (71, 72), and a space (LA) having a width of 2 mm or more along the radial direction of the bobbin (20) is formed between the first coil (101) and the second coil (201).

[0084]

[10] The bobbin (20) comprises a third cylindrical portion (23) which is the cylindrical portion (21-24) connected to the second cylindrical portion (22), the third cylindrical portion (23) being connected to at least two of the flange portions (71, 72) of the second cylindrical portion (22) and having at least a pair of flange portions (73, 74), a third coil (102) formed by winding a conductor around the third cylindrical portion (23) while rotating the third cylindrical portion (23) between the pair of flange portions (73, 74), and a space (LA) having a width of 2 mm or more along the radial direction of the bobbin (20) is formed between the second coil (201) and the third coil (102).

[0085]

[11] The bobbin (20) comprises a fourth cylindrical portion (24) which is the cylindrical portion (21-24) connected to the third cylindrical portion (23), the fourth cylindrical portion (24) being connected to at least two of the flange portions (73, 74) of the third cylindrical portion (23) and having at least a pair of flange portions (75, 76), a fourth coil (202) formed by winding a conductor around the fourth cylindrical portion (24) while rotating the fourth cylindrical portion (24) between the pair of flange portions (75, 76), and a space LA having a width of 2 mm or more along the radial direction of the bobbin (20) is formed between the third coil (102) and the fourth coil (202).

[0086]

[12] The transformer (1) described in [9], wherein the second cylindrical portion (22) is connected to two flange portions (42, 43) located at both ends of the second region (63) of the first cylindrical portion (21).

[0087]

[13] The transformer (1) according to [8] or [9], wherein the magnetic core (10) is made of an amorphous alloy ribbon or a nanocrystalline alloy ribbon.

[0088]

[14] The transformer (1) according to

[13] , wherein the magnetic core (10) is made of a nanocrystalline alloy ribbon having a thickness of 20 μm or less.

[0089]

[15] The transformer (1) according to

[13] , further comprising a support frame (301) that supports the magnetic core (10).

[0090]

[16] The transformer (1) according to [9], wherein the width of the first region (61) and the third region (63) along the axial direction is 10 mm or more.

[0091]

[17] The transformer (1) described in [9] is provided with a spacer material (82) arranged between the magnetic core (10) and the bobbin (20), and a space (LA) having a width of 2 mm or more along the radial direction of the bobbin (20) is formed between the straight portion (10A) of the magnetic core (10) and the first coil (101).

[0092]

[18] The transformer (1) described in [9], wherein the first coil (101) and the second coil (201) are formed to be offset in the axial direction of the bobbin (20).

[0093]

[19] The transformer (1) according to

[18] , wherein the width of the deviation is 20 mm or more and 60 mm or less.

[0094] (Note) Although the embodiments of the present invention have been described above, the invention according to the claims is not limited to the above-described embodiments. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention. Furthermore, the present invention can be implemented by modifying it as appropriate within the scope of its purpose.

[0095] According to the multi-layer rotary bobbin and the transformer using the same of the present invention, partial discharge between the coils can be sufficiently suppressed while improving the workability of the winding work.

[0096] REFERENCE SIGNS LIST 1... transformer 10... magnetic core 10A... straight portion 20... bobbin (multilayer rotating bobbin) 21... first cylindrical portion 22... second cylindrical portion 23... third cylindrical portion 24... fourth cylindrical portion 31... gear portion 41... first flange portion 42... second flange portion 43... third flange portion 44... fourth flange portion 61... first region 62... second region 63... third region 71 to 76... flange portion 101... first coil 102... third coil 201... second coil 202... fourth coil LA... space

Claims

1. A multi-layer rotating bobbin having a multi-layer structure in which a plurality of cylindrical portions with different diameters are connected in the radial direction, rotatably provided on a member to be attached, and configured to form a plurality of coils by winding conducting wires around each of the plurality of cylindrical portions.

2. A multi-layer rotating bobbin having a multi-layer structure in which a plurality of cylindrical portions with different diameters are connected in the radial direction, the cylindrical portions being composed of a combination of a plurality of divided pieces, having a first cylindrical portion which is the cylindrical portion with the smallest diameter, and a second cylindrical portion which is the cylindrical portion connected to the first cylindrical portion, the first cylindrical portion having a gear portion for rotating the first cylindrical portion by an external driving force and at least four flange portions formed at intervals in the axial direction, the outer peripheral surface of the first cylindrical portion being partitioned into at least three regions, namely a first region, a second region, and a third region, from one end in the axial direction to the other end by the four flange portions, the second region having a first coil forming portion for forming a first coil, the second cylindrical portion being connected to at least two of the flange portions of the first cylindrical portion and having at least a pair of flange portions, and having a second coil forming portion for forming a second coil between the pair of flange portions of the second cylindrical portion.

3. The multi-layer rotating bobbin according to claim 2, further comprising a third cylindrical portion which is the cylindrical portion connected to the second cylindrical portion, the third cylindrical portion being connected to at least two of the flange portions of the second cylindrical portion and having at least a pair of flange portions, and having a third coil forming portion for forming a third coil between the pair of flange portions of the third cylindrical portion.

4. The multi-layer rotating bobbin according to claim 3, further comprising a fourth cylindrical portion which is the cylindrical portion connected to the third cylindrical portion, the fourth cylindrical portion being connected to at least two of the flange portions of the third cylindrical portion and having at least a pair of flange portions, and having a fourth coil forming portion for forming a fourth coil between the pair of flange portions of the fourth cylindrical portion.

5. The multi-layer rotating bobbin according to claim 2, wherein the second cylindrical portion is connected to two flange portions located at both ends of the second region of the first cylindrical portion.

6. The multi-layer rotating bobbin according to claim 2, wherein a notch portion is formed in each flange portion.

7. The multi-layer rotating bobbin according to claim 2, wherein the widths of the first region and the third region along the axial direction are 10 mm or more.

8. An annular magnetic core having a straight portion, a multilayer structure in which a plurality of cylindrical portions with different diameters are connected in the radial direction, a bobbin rotatably provided on the straight portion, and a plurality of coils formed by winding a conducting wire around each of the plurality of cylindrical portions, wherein a space having a width of 2 mm or more along the radial direction of the bobbin is formed between the coil and the cylindrical portion on the outer side in the radial direction thereof, the transformer.

9. An annular magnetic core having a straight portion, a bobbin having a coil and disposed on the straight portion of the magnetic core, wherein the bobbin is a multilayer rotary bobbin having a multilayer structure in which a plurality of cylindrical portions with different diameters are connected in the radial direction, and includes a first cylindrical portion which is the cylindrical portion with the smallest diameter disposed so as to surround the straight portion of the magnetic core, and a second cylindrical portion which is the cylindrical portion connected to the first cylindrical portion, wherein the cylindrical portion is configured by combining a plurality of divided pieces, the first cylindrical portion has a gear portion for rotating the bobbin by an external driving force, and at least four flange portions formed spaced apart in the axial direction, and the outer peripheral surface of the first cylindrical portion is partitioned into at least three regions, i.e., a first region, a second region, and a third region, from one side in the axial direction to the other side by the four flange portions, the second region includes a first coil formed by winding a conducting wire while rotating the first cylindrical portion, the second cylindrical portion is connected to at least two of the flange portions of the first cylindrical portion and has at least a pair of flange portions, and a second coil formed by winding a conducting wire while rotating the second cylindrical portion is provided between the pair of flange portions of the second cylindrical portion, and a space having a width of 2 mm or more along the radial direction of the bobbin is formed between the first coil and the second coil, the transformer.

10. The bobbin includes a third cylindrical portion which is the cylindrical portion connected to the second cylindrical portion, the third cylindrical portion is connected to at least two of the flange portions of the second cylindrical portion and has at least a pair of flange portions, a third coil formed by winding a conducting wire while rotating the third cylindrical portion is provided between the pair of flange portions of the third cylindrical portion, and a space having a width of 2 mm or more along the radial direction of the bobbin is formed between the second coil and the third coil, the transformer according to claim 9.

11. The bobbin includes a fourth cylindrical portion which is the cylindrical portion connected to the third cylindrical portion. The fourth cylindrical portion is connected to at least two of the flange portions of the third cylindrical portion and has at least a pair of flange portions. Between the pair of flange portions of the fourth cylindrical portion, there is provided a fourth coil formed by winding a conducting wire while rotating the fourth cylindrical portion. A space having a width of 2 mm or more along the radial direction of the bobbin is formed between the third coil and the fourth coil. The transformer according to claim 10.

12. The second cylindrical portion is connected to two flange portions located at both ends of the second region of the first cylindrical portion. The transformer according to claim 9.

13. The magnetic core is formed using an amorphous alloy ribbon or a nanocrystalline alloy ribbon. The transformer according to claim 8 or 9.

14. The magnetic core is formed using a nanocrystalline alloy ribbon having a thickness of 20 μm or less. The transformer according to claim 13.

15. The transformer according to claim 13 further includes a support frame for supporting the magnetic core.

16. The widths along the axial direction of the first region and the third region are 10 mm or more. The transformer according to claim 9.

17. A spacer material is provided between the magnetic core and the bobbin. A space having a width of 2 mm or more along the radial direction of the bobbin is formed between the linear portion of the magnetic core and the first coil. The transformer according to claim 9.

18. The first coil and the second coil are formed with a shift in the axial direction of the bobbin. The transformer according to claim 9.

19. The width of the shift is 20 mm or more and 60 mm or less. The transformer according to claim 18.

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