transformer

Abstract

To provide a transformer that can be made compact even when it has a high-voltage coil. [Solution] A transformer comprising an iron core inserted into an upright molded coil and a holder that holds the end of the iron core, wherein an insulating spacer 40 is interposed between the molded coil and the holder, and a plurality of grooves 43 extending in a direction intersecting the vertical direction are formed on the side of the insulating spacer 40 along the vertical direction.

Description

Technical Field

[0001] The present invention relates to a transformer.

Background Art

[0002] Patent Document 1 discloses a molded transformer having a resin-molded primary coil and a resin-molded secondary coil disposed on the inner periphery of the primary coil, and by providing spacers above and below the primary coil and the secondary coil, the insulation performance between the primary coil and the secondary coil can be maintained while fixing the primary coil and the secondary coil and improving the earthquake resistance performance.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a transformer as described above, iron cores extending in the vertical direction are respectively inserted inside the primary coil and the secondary coil (hereinafter referred to as both coils) related to each phase, and both ends of each iron core are held by holding brackets. Further, since the holding brackets have electrical conductivity, an insulating spacer is interposed between the holding brackets and both coils for insulation between both coils.

[0005] According to the ground voltage value of both coils, the insulation distance required for insulation from the holding brackets changes. When the ground voltage value of both coils is large (high voltage), although it is necessary to ensure a long insulation distance, when the insulation distance becomes long, the size of the spacer becomes large, which hinders the miniaturization of the transformer. However, Patent Document 1 has not devised a solution to such a problem and cannot cope with it.

[0006] This invention has been made in view of these circumstances, and aims to provide a transformer that can be made more compact even when it has a high-voltage coil. [Means for solving the problem]

[0007] The transformer according to the present invention comprises an iron core inserted into an upright molded coil and a holder that holds the end of the iron core, wherein an insulating spacer is interposed between the molded coil and the holder, and a plurality of grooves extending in a direction intersecting the vertical direction are formed on the side of the insulating spacer along the vertical direction. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a transformer that can be made more compact even when it has a high-voltage coil. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic front view showing the configuration of a three-phase molded transformer according to Embodiment 1. [Figure 2] This figure shows the insulating spacer for a molded transformer according to Embodiment 1. [Figure 3] This figure shows the insulating spacer for a molded transformer according to Embodiment 2. [Figure 4] This figure shows the frustum-shaped part of the insulating spacer of the molded transformer according to Embodiment 3. [Modes for carrying out the invention]

[0010] The present invention will be described below with reference to the drawings illustrating its embodiments.

[0011] (Embodiment 1) Figure 1 is a schematic front view showing the configuration of a three-phase molded transformer 100 according to Embodiment 1. The molded transformer 100 uses a molded coil 10 obtained by winding a conductor covered with insulating paper and then molding the resulting winding with a thermosetting resin composition such as epoxy resin.

[0012] The molded transformer 100 is equipped with three vertically mounted molded coils 10. The three molded coils 10 consist of a U-phase molded coil 10, a V-phase molded coil 10, and a W-phase molded coil 10. The three molded coils 10 are arranged side by side at a predetermined interval.

[0013] In the molded coil 10 of each phase, the primary coil is formed as a cylindrical body using a thermosetting resin composition, as described above. The secondary coil is also formed as a cylindrical body with a smaller diameter than the primary coil using a thermosetting resin composition, as described above.

[0014] Each phase molded coil 10 consists of a secondary coil inserted inside a primary coil, and the primary and secondary coils have a multi-cylinder shape. Each molded coil 10 (primary coil) is provided with a tap switching section 80, including a tap switching terminal, on the lower part of its outer surface and front side. In addition, each phase molded coil 10 is provided with a rectangular plate-shaped primary terminal 70 corresponding to the primary coil of each phase on the upper part of its outer surface and front side.

[0015] An iron core 20 is inserted inside each phase's molded coil 10 (secondary coil). The iron core 20 has three vertical columns 22 (see dotted lines in Figure 1) that are inserted vertically inside the secondary coil of each phase's molded coil 10, an upper horizontal column 21 that connects the upper ends of the three vertical columns 22, and a lower horizontal column 23 that connects the lower ends of the three vertical columns 22, forming an annular magnetic circuit. That is, the upper horizontal column 21 and the lower horizontal column 23 are connected to the upper and lower ends of the three vertical columns 22 that have emerged from each phase's molded coil 10, respectively. In addition, a rectangular plate-shaped secondary terminal 60 corresponding to the secondary coil of each phase is provided at the upper end of the upper horizontal column 21.

[0016] The upper horizontal column section 21 and the lower horizontal column section 23 of the iron core 20 are each held by a retaining bracket 30 (retaining body). Each retaining bracket 30 is made of, for example, an H-shaped steel and extends along the upper horizontal column section 21 and the lower horizontal column section 23, and is positioned away from the molded coil 10 of each phase in an upward or downward direction. Legs 50 for erecting the molded transformer 100 are attached to the lower surface of the lower retaining bracket 30.

[0017] An insulating spacer 40 is interposed between each phase's molded coil 10 and each retaining bracket 30. More specifically, multiple insulating spacers 40 (hereinafter also referred to as upper insulating spacers 40) are interposed between the upper end surface of each phase's molded coil 10 and the lower surface of the upper retaining bracket 30, and multiple insulating spacers 40 (hereinafter also referred to as lower insulating spacers 40) are interposed between the lower end surface of each phase's molded coil 10 and the upper surface of the lower retaining bracket 30.

[0018] Figure 2 shows the insulating spacer 40 of the molded transformer 100 according to Embodiment 1. The insulating spacer 40 consists of multiple parts (see Figure 2A).

[0019] The insulating spacer 40 includes one rectangular parallelepiped part 41 (part) and a plurality of frustum-shaped parts 42 (parts) (see FIGS. 2B and 2C). That is, the insulating spacer 40 is provided such that the rectangular parallelepiped part 41 and the frustum-shaped parts 42 can be separated from each other, and the frustum-shaped parts 42 can be separated from each other. The plurality of frustum-shaped parts 42 have the same shape. One rectangular parallelepiped part 41 and the plurality of frustum-shaped parts 42 are connected in the vertical direction to form a row.

[0020] More specifically, the plurality of frustum-shaped parts 42 are aligned with their upper ends facing upward to form a row 420, and the rectangular parallelepiped part 41 is disposed on the tip side of the frustum-shaped part 42 disposed at the upper end in such a row 420.

[0021] The rectangular parallelepiped part 41 is made of an insulating material and has a rectangular thick plate shape with a wide main surface on the upper surface 411 (opposing surface) and the lower surface 412. An engaging recess 413 corresponding to the engaging protrusion 421 of the frustum-shaped part 42 described later is recessed in the lower surface 412.

[0022] Each frustum-shaped part 42 is made of the same insulating material as the rectangular parallelepiped part 41 and has a frustum shape with the upper surface 422 and the lower surface 423 (opposing surfaces) parallel to each other and flat. Both the upper surface 422 and the lower surface 423 are rectangular, and the upper surface 422 is narrower than the lower surface 423. Further, the frustum-shaped part 42 has four inclined surfaces 424 adjacent to the upper surface 422 and the lower surface 423, and each inclined surface 424 is inclined obliquely with respect to the vertical direction, that is, the direction in which the plurality of frustum-shaped parts 42 are connected.

[0023] [[ID= The upper insulating spacer 40 is interposed between the mold coil 10 and the upper holding fitting 30, and the upper surface 411 of the rectangular parallelepiped part 41 and the lower surface 423 of the lowermost frustum-shaped part 42 in the row 420 are disposed so as to face the upper holding fitting 30 and the mold coil 10 of each phase, respectively. Furthermore, the lower insulating spacer 40 is interposed between the molded coil 10 and the lower retaining bracket 30, and the upper surface 411 of the rectangular parallelepiped part 41 and the lower surface 423 of the frustoconical part 42 at the lower end of the row 420 are arranged to face the molded coil 10 and the lower retaining bracket 30 of each phase, respectively.

[0024] Each frustoconical part 42 has a protruding engagement projection 421 on its upper surface 422 and a recessed engagement recess 425 on its lower surface 423. The engagement projection 421 extends along the length of the upper surface 422, and the engagement recess 425 extends along the length of the lower surface 423, with the shapes of the engagement projection 421 and the engagement recess 425 corresponding to each other.

[0025] The engaging projection 421 of each frustoconical part 42 engages with the engaging recess 425 of the adjacent upper frustoconical part 42, and the engaging recess 425 of each frustoconical part 42 engages with the engaging projection 421 of the adjacent lower frustoconical part 42. In addition, the engaging projection 421 of the frustoconical part 42 located at the upper end of the row 420 of frustoconical parts 42 engages with the engaging recess 413 of the rectangular parallelepiped part 41. As a result, in the row consisting of the rectangular parallelepiped part 41 and the multiple frustoconical parts 42, the positions of the rectangular parallelepiped part 41 and each frustoconical part 42 are determined, and the rectangular parallelepiped part 41 and each frustoconical part 42 are held in place.

[0026] In each insulating spacer 40, as described above, one rectangular parallelepiped part 41 and multiple frustoconical parts 42 are arranged in a row in the vertical direction. Therefore, multiple grooves 43 are formed on the sides of each phase, excluding the upper surface 411 of the rectangular parallelepiped part 41 and the lower surface 423 of the frustoconical part 42 that face the molded coil 10 or retaining fitting 30 of each phase. Each groove 43 extends in a direction intersecting the vertical direction, and multiple grooves 43 are formed at equal intervals in the vertical direction.

[0027] In other words, in each insulating spacer 40, a groove 43 is formed between two adjacent parts, where one surface of one part and one surface of the other part form a groove 43. More specifically, in areas where the rectangular parallelepiped part 41 and the frustoconical part 42 are adjacent, the lower surface 412 of the rectangular parallelepiped part 41 (one surface of one part) and the inclined surface 424 of the frustoconical part 42 (one surface of the other part) form a groove 43. In areas where the frustoconical parts 42 are adjacent, the lower surface 423 of the upper frustoconical part 42 (one surface of one part) and the inclined surface 424 of the lower frustoconical part 42 (the other surface of the other part) form a groove 43.

[0028] The dimensions of the groove 43 in the vertical direction vary depending on the ground voltage of the molded coil 10. That is, since the insulation distance (creepage distance) changes depending on the ground voltage, the dimensions of the groove 43 in the vertical direction (hereinafter referred to as the vertical dimensions of the groove 43) are determined in order to achieve sufficient insulation effect.

[0029] As described above, in the molded transformer 100 according to Embodiment 1, the insulating spacer 40 has a plurality of grooves 43 on its sides, excluding the upper surface 411 of the rectangular parallelepiped part 41 and the lower surface 423 of the frustoconical part 42. Therefore, compared to the case without grooves 43, the insulation distance in the vertical direction, i.e., the insulation distance between the molded coil 10 and the retaining fitting 30, can be extended, and the molded transformer 100 can be made more compact by reducing the dimensions of the insulating spacer 40 in the vertical direction while improving insulation performance.

[0030] Furthermore, in the molded transformer 100 according to Embodiment 1, the insulating spacer 40 consists of one rectangular parallelepiped part 41 and a plurality of frustoconical parts 42. For example, by adjusting the number of frustoconical parts 42, the vertical dimension of the insulating spacer 40, i.e., the insulating distance, can be adjusted.

[0031] The required insulation distance between the molded coil 10 and the retaining bracket 30 varies depending on the voltage value of the molded coil 10 to ground. In contrast, in the molded transformer 100 according to Embodiment 1, the insulation distance can be easily changed by adjusting the vertical dimension of the insulating spacer 40 by adjusting the number of frustoconical parts 42. Therefore, it is not necessary to provide a dedicated insulating spacer 40 for each voltage value of the molded coil 10 to ground, and manufacturing costs can be reduced.

[0032] Furthermore, in the molded transformer 100 according to Embodiment 1, the upper surface 411 of the rectangular parallelepiped part 41 and the lower surface 423 of the frustoconical part 42 are arranged opposite the molded coil 10 and the retaining bracket 30, thereby supporting the molded coil 10 and the retaining bracket 30. Therefore, the wide surfaces of the rectangular parallelepiped part 41 and the frustoconical part 42 are used to support the molded coil 10 and the retaining bracket 30, thereby increasing stability.

[0033] In the above explanation, we have used the example of a case where multiple frustoconical parts 42 have the same shape, but we are not limited to this. For example, the insulating spacer 40 may include multiple frustoconical parts 42 with different dimensions in the vertical direction. In such a case, the dimensions of the insulating spacer 40 in the vertical direction, i.e., the vertical dimensions of the groove 43, can be adjusted more precisely.

[0034] Furthermore, the above description has used as an example the case in which the insulating spacer 40 is configured such that a rectangular parallelepiped part 41 is disposed on the tip side of the frustoconical part 42 that is located at the upper end of a row 420 of frustoconical parts 42 (hereinafter referred to as the first configuration), but it is not limited to this. For example, a configuration may be used in which multiple frustoconical parts 42 are arranged in a row 420 with their tips facing downwards, and a rectangular parallelepiped part 41 is disposed on the tip side of the frustoconical part 42 that is located at the lower end of such row 420 (hereinafter referred to as the second configuration). Furthermore, the second configuration insulating spacer 40 and the first configuration insulating spacer 40 may be used on the upper and lower sides of the molded coil 10 of each phase, respectively.

[0035] Furthermore, the above explanation has described an example in which the rectangular parallelepiped part 41 and the frustoconical part 42 in the insulating spacer 40 can be separated from each other, and the frustoconical parts 42 can be separated from each other, but the explanation is not limited to this. For example, one rectangular parallelepiped part 41 and multiple frustoconical parts 42 may be integrally formed.

[0036] (Embodiment 2) Figure 3 shows the insulating spacer 40 of the molded transformer 100 according to Embodiment 2. The insulating spacer 40 consists of multiple parts, similar to Embodiment 1.

[0037] The insulating spacer 40 includes one frustoconical part 42A and multiple frustoconical parts 42. That is, the insulating spacer 40 is provided such that the frustoconical part 42A and the frustoconical parts 42 can be separated from each other, and the frustoconical parts 42 can be separated from each other.

[0038] The frustum-shaped part 42A and each of the frustum-shaped parts 42 are substantially the same shape. The frustum-shaped part 42A and the multiple frustum-shaped parts 42 are connected vertically to form a row. The frustum-shaped part 42A and the multiple frustum-shaped parts 42 form a row with their tips facing in different directions. For the sake of explanation, the frustum-shaped part 42A and the frustum-shaped part 42 will be collectively referred to as frustum-shaped part 42, 42A.

[0039] Multiple frustum-shaped parts 42 are arranged in a row 420 with their tips facing upward, and a frustum-shaped part 42A is positioned on the tip side of the frustum-shaped part 42 positioned at the upward-facing tip in this row 420. The frustum-shaped parts 42 of the molded transformer 100 according to Embodiment 2 are the same as those in Embodiment 1, and a detailed explanation is omitted.

[0040] Furthermore, as described above, the frustoconical part 42A has substantially the same shape as the frustoconical part 42. The frustoconical part 42A has an upper surface 422A, a lower surface 423A, an inclined surface 424A, and an engaging recess 425A, which correspond to the upper surface 422, lower surface 423, inclined surface 424, and engaging recess 425 of the frustoconical part 42, respectively. However, the frustoconical part 42A does not have a portion corresponding to the engaging projection 421 of the frustoconical part 42, and differs from the frustoconical part 42 in that the engaging recess 425A is recessed in the upper surface 422A. In other words, as will be described later, the frustoconical part 42A is arranged so that the orientation of its tip is different from that of the frustoconical part 42, and has substantially the same shape as the frustoconical part 42.

[0041] As described above, the frustum-shaped part 42A and the multiple frustum-shaped parts 42 form a row with their tips facing in different directions. More specifically, the multiple frustum-shaped parts 42 form a row 420 with their tips aligned upwards, and in this row 420, the frustum-shaped part 42A is positioned on the tip side of the frustum-shaped part 42 positioned at the upper end, with its tip facing in the opposite direction to the multiple frustum-shaped parts 42, i.e., downwards.

[0042] The engaging projection 421 of each frustoconical part 42 engages with the engaging recess 425 of the adjacent upper frustoconical part 42, and the engaging recess 425 of each frustoconical part 42 engages with the engaging projection 421 of the adjacent lower frustoconical part 42. In addition, the engaging projection 421 of the frustoconical part 42 located at the upper end of the row 420 of frustoconical parts 42 engages with the engaging recess 425A of the frustoconical part 42A. As a result, in the row consisting of multiple frustoconical parts 42, 42A, the positions of the multiple frustoconical parts 42, 42A are determined, and the multiple frustoconical parts 42, 42 are held in place.

[0043] Similar to Embodiment 1, the insulating spacer 40 is interposed between the molded coil 10 and the retaining bracket 30. More specifically, the upper insulating spacer 40 is interposed between the molded coil 10 and the upper retaining bracket 30, and the lower surface 423A of the frustoconical part 42A and the lower surface 423 of the frustoconical part 42 at the lower end of row 420 are arranged to face the upper retaining bracket 30 and the molded coil 10 of each phase, respectively. Furthermore, the lower insulating spacer 40 is interposed between the molded coil 10 and the lower retaining bracket 30, and the lower surface 423A of the frustoconical part 42A and the lower surface 423 of the frustoconical part 42 at the lower end of row 420 are arranged to face the molded coil 10 and the lower retaining bracket 30 of each phase, respectively.

[0044] Each insulating spacer 40 has multiple grooves 43, 43A on its side, similar to Embodiment 1. The grooves 43, 43A extend in a direction intersecting the vertical direction, and multiple grooves 43 are formed at equal intervals in the vertical direction.

[0045] In each insulating spacer 40, in two adjacent parts, one surface of one adjacent part and one surface of the other part form a groove 43 or groove 43A. Specifically, in the region where frustoconical parts 42A and frustoconical parts 42 are adjacent, the inclined surface 424A of frustoconical part 42A (one surface of one part) and the inclined surface 424 of frustoconical part 42 (one surface of the other part) constitute a groove 43A, and in the region where two frustoconical parts 42 are adjacent, similar to Embodiment 1, the lower surface 423 of the upper frustoconical part 42 (one surface of one part) and the inclined surface 424 of the lower frustoconical part 42 (one surface of the other part) constitute a groove 43.

[0046] As described above, in the molded transformer 100 according to Embodiment 2, the insulating spacer 40 consists of a frustoconical part 42A and a frustoconical part 42, which are substantially the same shape, thus reducing manufacturing costs compared to the case where the shapes of the insulating spacer 40 parts are completely different.

[0047] Parts similar to those in Embodiment 1 are denoted by the same reference numerals, and detailed descriptions are omitted.

[0048] (Embodiment 3) The molded transformer 100 according to Embodiment 3 is equipped with an insulating spacer 40, similar to Embodiment 1 or Embodiment 2. The insulating spacer 40, similar to Embodiment 1 or Embodiment 2, consists of a plurality of parts arranged in a row, and the plurality of parts are separable from each other. The insulating spacer 40 of the molded transformer 100 according to Embodiment 3 includes a plurality of frustoconical parts 42B.

[0049] Figure 4 shows the frustoconical part 42B of the insulating spacer 40 of the molded transformer 100 according to Embodiment 3.

[0050] Each frustoconical part 42B has substantially the same shape as the frustoconical part 42 of Embodiment 1 and Embodiment 2. The frustoconical part 42B has an upper surface 422, a lower surface (not shown), an inclined surface 424, an engaging projection 421, and an engaging recess (not shown). These correspond to the upper surface 422, lower surface 423, inclined surface 424, engaging projection 421, and engaging recess 425 of the frustoconical part 42, respectively, so a detailed explanation is omitted.

[0051] Furthermore, in each frustoconical part 42B, grooves 426 (other grooves) are formed on each inclined surface 424. The grooves 426 extend in a direction intersecting the vertical direction, and multiple grooves are arranged side by side along this vertical direction.

[0052] Similar to Embodiments 1 and 2, the multiple frustoconical parts 42B are arranged in a vertical direction using the engaging projections 421 and engaging recesses 425, with their tips facing upward, when forming the insulating spacer 40.

[0053] The dimensions of the groove 426 in the vertical direction vary depending on the ground voltage of the molded coil 10. That is, since the insulation distance (creepage distance) changes depending on the ground voltage, the dimensions of the groove 426 in the vertical direction are determined in order to achieve sufficient insulation effect.

[0054] As described above, in the molded transformer 100 according to Embodiment 3, the insulating spacer 40 includes a frustoconical part 42B and has a plurality of grooves 43 on its side, and grooves 426 are also formed on the inclined surface 424 of each frustoconical part 42B. Therefore, compared to the case without groove 426, the insulation distance in the vertical direction, i.e., the insulation distance between the molded coil 10 and the retaining bracket 30, can be extended, improving insulation performance while reducing the dimensions of the insulation spacer 40 in the vertical direction, making the molded transformer 100 even more compact.

[0055] Parts similar to those in Embodiment 1 are denoted by the same reference numerals, and detailed descriptions are omitted.

[0056] The technical features (constituent elements) described in Embodiments 1 to 3 are combinable with each other, and by combining them, new technical features can be conceived. The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims, not in the sense described above, and all modifications within the sense and scope equivalent to the claims are intended.

[0057] The matters described in each embodiment can be combined with each other. Furthermore, the independent and dependent claims described in the claims can be combined with each other in any combination, regardless of the form of reference. In addition, the claims use a form in which claims referencing two or more other claims (multi-claim form), but are not limited to this. A form in which multi-claims referencing at least one multi-claim (multi-multi-claim) may also be used. [Explanation of symbols]

[0058] 10: Molded coil, 20: Iron core, 30: Retaining bracket, 40: Insulating spacer, 41: Rectangular parallelepiped part, 42, 42A, 42B: Frusting pyramidal part, 43: Groove, 100: Molded transformer, 411: Top surface (opposing surface), 420: Row, 423: Bottom surface (opposing surface), 424: Inclined surface, 426: Groove (other grooves)

Claims

1. A transformer comprising an iron core inserted into an upright molded coil and a holder that holds the end of the iron core, An insulating spacer is interposed between the molded coil and the holder, A transformer having multiple grooves formed along the vertical direction, extending in a direction intersecting the vertical direction, on the side of the insulating spacer.

2. The insulating spacer includes a plurality of parts arranged in the vertical direction, The transformer according to claim 1, wherein in two adjacent parts, one surface of one adjacent part and one surface of the other part form the groove.

3. The aforementioned plurality of parts include one rectangular parallelepiped part and a plurality of frustum-shaped parts. The aforementioned multiple frustum-shaped parts are arranged in a row with their tips aligned in one direction. The transformer according to claim 2, wherein the rectangular parallelepiped part is disposed on the tip side of the frustoconical part at the tip of the row in the aforementioned one direction.

4. Each part is a frustum-shaped part, The other frustum-shaped parts, with the exception of one, are arranged in a row with their tips aligned in one direction. The transformer according to claim 2, wherein one of the frustoconical parts is arranged on the tip side of the frustoconical part at the tip of the row in the aforementioned one direction, with the direction of its tip facing the opposite direction to the aforementioned one direction.

5. The transformer according to claim 3 or 4, wherein the inclined surface of each frustum-shaped part has other grooves formed thereon that extend in a direction intersecting the vertical direction.

Images