Stacked shafts for machines with constant induction.

Abstract

DEPCT64 In a stacked axis (1,21) for a machine with constant induction according to one configuration. The connection surfaces to which the bracing sections (2,3,12,22,23) and the leg sections (4,5,6,11,24,25,26) are attached will have protrusions. (8,13) constructed from a number of magnetic components (7) and a recessed area (9,14) constructed from A number of magnetic components are arranged alternately, and the mounting brackets and legs are configured accordingly. In a manner where the protrusions and recesses meet, each plate-like magnetic insulator (10,15) is Positioned at the junction between the protruding and recessed sections in a way that allows it to curve into a folded, extendable shape. Along the collision line, air gaps are established, and in relation to their number, A stacked magnetic assembly that creates individual protrusions and a number of magnetic components. A stacking design that creates individual recesses; the number of stacked magnetic components that create the protrusions. Each section is made in fewer pieces than the number of stacked magnetic components that create each recess. Consistent with the thickness of the magnetic insulation. -----------------------------------------------------------

Description

Laminated core for static induction equipment CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2018-206549 filed on November 1, 2018, the contents of which are incorporated herein by reference.

[0002] An embodiment of the present invention relates to a laminated core for a stationary induction machine.

[0003] Laminated cores, which are constructed by laminating multiple sheets of magnetic material such as silicon steel sheets, are known for use in static induction equipment, such as transformers (see, for example, Patent Document 1). In these laminated cores, the magnetic materials are alternately stacked at the butt joints between the upper and lower yoke sections and the legs connecting them. Furthermore, a non-magnetic sheet material is disposed at the joints connecting the yoke sections and the legs. This ensures an air gap corresponding to the thickness of the sheet material at the joints of the laminated core, reducing the residual magnetic flux density and suppressing magnetizing inrush currents.

[0004] JP 2010-287756 A

[0005] In the above-described configuration in which a non-magnetic sheet member is provided in the air gap portion of a laminated core, the thickness of the sheet member corresponds to the gap dimension, and adjusting the gap dimension makes it possible to control the magnetic characteristics. However, in the configuration described in Patent Document 1, the sheet member is also disposed in the area where the plate surfaces of the laminated magnetic material overlap, creating a gap corresponding to the thickness of the sheet member. This results in unnecessary gaps between the magnetic material members, which leads to an increase in the size of the laminated core in the stacking direction. In particular, the gaps become larger when the thickness of the sheet member increases.

[0006] Therefore, we provide a laminated core for a stationary induction device that is constructed by laminating magnetic materials and that can provide an appropriate air gap to control magnetic properties without increasing the size in the lamination direction.

[0007] A laminated core for a stationary induction device according to an embodiment includes upper and lower yoke sections formed by laminating a plurality of sheets of plate-shaped magnetic material, and at least two legs formed by laminating a plurality of sheets of plate-shaped magnetic material and connecting both ends of the upper and lower yoke sections vertically, and is configured by butt-joining the yoke sections and the legs, and the joint surface where the yoke section and the legs are joined has alternating convex sections formed by a plurality of sheets of magnetic material and concave sections formed by a plurality of sheets of magnetic material, and the yoke section and the legs are butted together so that the convex sections and concave sections interlock with each other, and at the butt-joint portion between the convex sections and the concave sections, a sheet-like magnetic insulator is arranged in a bellows-like bent form along the butt line to provide an air gap, and the relationship between the number of laminated sheets of magnetic material forming the convex sections and the number of laminated sheets of magnetic material forming the concave sections is such that the number of laminated sheets of magnetic material forming the convex sections is smaller than the number of laminated sheets of magnetic material forming the concave sections in accordance with the thickness of the magnetic insulator.

[0008] Figure 1 is a front view showing a schematic representation of the overall configuration of a laminated core according to the first embodiment, Figure 2 is a front view showing the disassembled lower half of the laminated core according to the first embodiment, Figure 3 is an enlarged cross-sectional view of the joint between the yoke portion and the leg portion according to the first embodiment, Figure 4 is an exploded oblique view showing how an insulator is attached to the joint surface according to the first embodiment, Figure 5 is an enlarged cross-sectional view of the joint between the yoke portion and the leg portion according to the second embodiment, and Figure 6 is a front view showing a schematic representation of the overall configuration of a laminated core according to the third embodiment.

[0009] (1) First Embodiment A first embodiment applied to a three-phase transformer as a stationary induction device will be described below with reference to Figs. 1 to 4. Fig. 1 shows the overall configuration of a laminated core 1 for a transformer according to this embodiment. This laminated core 1 includes an upper yoke portion 2 and a lower yoke portion 3 extending in the left-right direction in the figure, and three legs (first, second, and third) 4, 5, and 6 extending in the up-down direction and connecting the yoke portions 2 and 3 vertically. Windings (not shown) are attached to each of the legs 4, 5, and 6. Note that when directions are mentioned in the following description, the state of Fig. 1 will be described as a front view.

[0010] The yoke portions 2, 3 and the legs 4, 5, and 6 that make up the laminated core 1 are each formed by stacking a plurality of plate-shaped magnetic materials, such as silicon steel plates 7 (see FIG. 3), in the front-to-back direction in the figure. The yoke portions 2, 3 and the legs 4, 5, and 6 are then butt-joined to form the entire laminated core 1. In this embodiment, as shown in FIG. 3, the thickness of one silicon steel plate 7 is dimension t. As a specific example, the thickness dimension t is, for example, 0.2 to 0.3 mm.

[0011] In this case, in the laminated core 1 of this embodiment, the four upper, lower, left, and right corners of the butt joints where the left and right ends of the yoke portions 2, 3 and the upper and lower ends of the first and third legs 4, 6 are joined are cut at an angle of approximately 45 degrees to form a so-called frame-like butt joint. Also, the joints between the central portions of the yoke portions 2, 3 and the upper and lower ends of the second leg 5 are formed as V-shaped convex portions at the top and bottom of the second leg 5, forming a concave-convex butt joint, a so-called lap joint type joint.

[0012] 3 and 4, the butt joints between the yoke portions 2, 3 and the first, second, and third leg portions 4, 5, and 6 have a configuration in which the joint surfaces of both have convex portions 8 and concave portions 9 alternating in the lamination direction of the silicon steel plates 7. The yoke portions 2, 3 and the leg portions 4, 5, and 6 are joined at a total of eight joints. In this case, one V-shaped portion of the second leg portion 5 is counted as two joints. As shown in FIG. 3, at the eight joints, the convex portions 8 and concave portions 9 are butt-joined so that they interlock with each other, and a so-called lap joint type joining method is used.

[0013] More specifically, in this embodiment, as shown in Fig. 3, a convex portion 8 is formed from n stacked silicon steel plates 7, for example, two sheets. Also, a concave portion 9 is formed from m stacked silicon steel plates 7, for example, four sheets. In this case, each of the yoke portions 2, 3 and leg portions 4, 5, 6 is formed by stacking a large number of silicon steel plates 7 cut to a predetermined size in advance while aligning them in a predetermined order, so that multiple sets of convex portions 8 and concave portions 9 are formed alternately at the joints.

[0014] For example, with respect to one leg 4, joints are provided at both the upper and lower ends, and in this case, the convex portions 8 are arranged at the same positions at both ends in the stacking direction. The convex portions 8 and the concave portions 9 may be formed in the reverse order in the stacking direction at both the upper and lower ends. Of course, the convex portions 8 and the concave portions 9 at the joints of the mating yoke portions 2, 3 are arranged in a corresponding relationship, i.e., a relationship in which the convex and concave portions interlock. In this case, in this embodiment, it is sufficient to prepare silicon steel plates 7 of at most three different lengths: silicon steel plates 7 having convex portions 8 at both ends, silicon steel plates 7 having concave portions 9 at both ends, and silicon steel plates 7 having a convex portion 8 at one end and a concave portion 9 at the other. When the convex portions 8 and the concave portions 9 are formed in the reverse order at both ends in the stacking direction, it is possible to suffice with silicon steel plates 7 of two different lengths: silicon steel plates 7 having a convex portion 8 at one end and a concave portion 9 at the other, and silicon steel plates 7 having concave portions 9 at both ends.

[0015] In this embodiment, as shown in Figures 3 and 4, the butt lines between the yoke portions 2, 3 and the legs 4, 5, and 6 are formed in a shape that extends in the stacking direction while bending like bellows, i.e., a shape that resembles a series of convex and concave portions bent at right angles. Figure 3 shows the joint between the first leg portion 4 and the lower yoke portion 3 as a representative example. An accordion-shaped sheet-like magnetic insulator 10 is then placed along the butt lines to provide an air gap. The magnetic insulator 10 is made of insulating paper such as aramid paper and has a thickness g that is equal to the thickness t of the silicon steel plate 7. This provides an air gap corresponding to the thickness g of the magnetic insulator 10.

[0016] Therefore, the air gap is formed between the tip surface of the convex portion 8 and the bottom surface of the concave portion 9, and between the side surface of the convex portion 8 and the inner surface of the concave portion 9, in a shape such that convex and concave portions are bent at right angles and are repeated in a continuous U-shaped pattern. In this case, the magnetic insulator 10 is formed in advance by bending a single sheet into an accordion-like shape, as shown in Figure 4, and is fitted, for example, onto the abutting surfaces of the legs 4, 5, and 6 so as to cover the convex portions 8 and the concave portions 9. Thereafter, the yoke portions 2, 3 and the legs 4, 5, and 6 are joined.

[0017] In this embodiment, the relationship between the number n of stacked silicon steel plates 7 forming the protrusions 8 and the number m of stacked silicon steel plates 7 forming the recesses 9 is m = (n + 2k). k is a value indicating the relationship between the thickness t of one silicon steel plate 7 and the thickness g of the magnetic insulator 10. In other words, k is a value indicating how many (k) silicon steel plates 7 the thickness g of the magnetic insulating portion 10 corresponds to, and is a natural number. In this embodiment, k = 1. Therefore, m = (n + 2), and if n is 2, m is 4. In this way, the number of stacked silicon steel plates 7 forming the protrusions 8 is smaller than the number of stacked silicon steel plates 7 forming the recesses 9. This allows the magnetic insulators 10 to be arranged almost densely between the protrusions 8 and the recesses 9.

[0018] Next, we will briefly describe the assembly procedure for the laminated core 1 configured as described above. The upper yoke 2, lower yoke 3, and three legs 4, 5, and 6 that make up the laminated core 1 are each obtained by stacking multiple silicon steel plates 7 that have been cut to the required shape in advance and then fastening them together, for example, by adhesive bonding. At this time, the joint surfaces of the legs 4, 5, and 6 are configured to have convex portions 8 and concave portions 9 alternating in the stacking direction. The joint surfaces of the yokes 2 and 3 are configured so that the concave portions 9 and convex portions 8 correspond to the convex portions 8 and concave portions 9, i.e., so that they interlock with each other.

[0019] 4, a magnetic insulator 10 previously shaped like a bellows to fit the convex portions 8 and concave portions 9 is fitted and disposed on each joint surface of the legs 4, 5, and 6. Next, as shown in FIG. 2, the joint surfaces of the legs 4, 5, and 6 are butt-joined to the joint portion of the upper part of the lower yoke portion 3 so that the convex portions 8 and concave portions 9 mesh with each other. After this, windings (not shown) are attached to each of the legs 4, 5, and 6, and then the upper yoke portion 2 is butt-joined in the same manner so that the convex portions 8 and concave portions 9 mesh with each other. For this joining, a well-known method using, for example, a clamping member or a fastening member can be used.

[0020] As a result, as shown in Figure 3, the joints between the yokes 2 and 3 and the legs 4, 5, and 6 are butt-joined by a so-called lap joint method, with the convex portions 8 and concave portions 9 arranged alternately in the stacking direction meshing with each other. At the joints, butt lines are formed in an accordion-like shape extending in the stacking direction, and sheet-like magnetic insulators 10 are placed along the butt lines, thereby providing air gaps at the joints. The magnetic insulators 10, which have been previously shaped into an accordion-like shape, can be assembled to the joint surfaces, which of course makes assembly of the magnetic insulators 10 easy. Alternatively, the magnetic insulators 10 may be fitted and arranged on the yokes 2 and 3 sides, and then butt-joined to the legs 4, 5, and 6 sides.

[0021] The laminated core 1 of this embodiment can provide the following actions and effects. That is, in the laminated core 1 configured as described above, a magnetic insulator 10 is disposed between the yoke portions 2, 3, which are formed by stacking silicon steel plates 7, and the legs 4, 5, 6, to provide an air gap. In this case, the relationship between the number of stacked silicon steel plates 7 forming the convex portions 8 and the number of stacked silicon steel plates 7 forming the concave portions 9 is as follows: That is, in accordance with the thickness dimension g of the magnetic insulator 10, the number of stacked silicon steel plates 7 forming the convex portions 8 is made smaller than the number of stacked silicon steel plates 7 forming the concave portions 9.

[0022] 3, the thickness g of the magnetic insulator 10 corresponds to the thickness t of one (k=1) silicon steel plate 7. In contrast, the convex portion 8 is formed from n silicon steel plates 7, in this case two silicon steel plates 7, and the concave portion 9 is formed from (n+2) silicon steel plates 7, in this case four silicon steel plates 7. As a result, a space is formed between the convex portion 8 and the concave portion 9, in which the sheet-like magnetic insulator 10 is densely arranged along the butt line, and the magnetic insulator 10 is arranged in this space in a bellows-like bent shape, providing an air gap.

[0023] With this configuration, even when the silicon steel plates 7 are stacked in close contact, no extra gaps are formed in the stacking direction, and it is possible to prevent each part of the laminated core 1 from becoming large. As a result, according to this embodiment, when the silicon steel plates 7 are stacked and joined in a meshing state between the protrusions 8 and the recesses 9, it is possible to obtain the excellent effect of being able to provide an appropriate air gap for controlling the magnetic characteristics without increasing the size in the stacking direction.

[0024] In particular, in this embodiment, the joints between the yoke portions 2, 3 and the legs 4, 5, 6 are butted at an angle, forming a frame-like joint, which allows for a larger joint surface area, and ultimately a larger magnetic path area and a smaller magnetic resistance. The transformer can be applied to power electronics transformers used in data centers, for example, and can achieve space savings, higher efficiency, and improved reliability.

[0025] (2) Second Embodiment Fig. 5 shows a second embodiment, for example, showing the configuration of the joint between the left leg 11 and the lower yoke 12. This second embodiment differs from the first embodiment in the thickness g of the sheet-like magnetic insulator 15 disposed between the protrusion 13 and the recess 14, i.e., the size of the air gap.

[0026] That is, in this embodiment, the thickness g of the magnetic insulator 15 corresponds to twice (k=2) the thickness t of one silicon steel plate 7 serving as the magnetic material. At the same time, the protrusion 13 is formed from n silicon steel plates 7, three in this case, and the recess 14 is formed from (n+2k) silicon steel plates 7, seven in this case. As a result, a space with a width of 2t (=g) is formed between the protrusion 13 and the recess 14, in which the sheet-like magnetic insulator 15 is densely arranged along the butt line, and the magnetic insulator 15 is arranged in this space in a bellows-like bent form, providing an air gap.

[0027] Therefore, in the second embodiment, similarly to the first embodiment, the silicon steel plates 7 are stacked and joined in an interlocking state between the convex portions 13 and the concave portions 14, and the excellent effect of being able to provide an appropriate air gap for controlling the magnetic properties can be obtained without increasing the size in the stacking direction.

[0028] In this way, the thickness g of the magnetic insulator 15, i.e., the size of the air gap, can be set to correspond to an integer multiple of the thickness t of one of the silicon steel plates 7 serving as the plate-like magnetic material. This not only makes it possible to provide an air gap corresponding to the thickness of one of the silicon steel plates 7, but also makes it possible to adjust the size of the air gap by employing a magnetic insulator 15 that is thicker, i.e., has a thickness that is an integer multiple of the thickness of one of the silicon steel plates 7. As a result, it becomes possible to control the magnitude of the excitation current as required.

[0029] (3) Third embodiment and other embodiments Fig. 6 shows a third embodiment, and schematically illustrates the overall configuration of a laminated core 21. This laminated core 21 also includes upper and lower yoke sections 22, 23, and three legs 24, 25, 26 that vertically connect the yoke sections 22, 23. These yoke sections 22, 23 and the legs 24, 25, 26 are each formed by stacking a plurality of plate-shaped magnetic materials, such as silicon steel plates 7, in the front-to-rear direction in the figure.

[0030] In this case, in the laminated core 21 of this embodiment, the butt joints at both left and right ends of the yoke portions 22, 23 are cut into an L-shape, and the upper and lower ends of the first and third legs 24, 26 are joined. The upper and lower ends of the first and third legs 24, 26 each have two L-shaped surfaces that serve as joining surfaces to the yoke portions 22, 23. Meanwhile, the central portions of the yoke portions 22, 23 are cut into a U-shape, and the upper and lower ends of the second leg 25 are joined. The upper and lower ends of the second leg 25 each have three U-shaped surfaces that serve as joining surfaces to the yoke portions 22, 23.

[0031] Although not shown in detail, the butt joints between the yoke portions 22, 23 and the leg portions 24, 25, 26 have a configuration in which the joint surfaces of both have convex portions 8 and concave portions 9 alternating in the stacking direction of the silicon steel plates 7. The yoke portions 22, 23 and the leg portions 24, 25, 26 are butt-joined such that the convex portions 8 and the concave portions 9 interlock with each other. Although not shown in the figures, in this case as well, an air gap is provided by arranging a sheet-like magnetic insulator 10 bent in an accordion-like shape along the butt joint lines where the convex portions 8 and the concave portions 9 interlock with each other, as in the first embodiment and the like.

[0032] The relationship between the number n of laminated silicon steel plates 7 forming the convex portions 8 and the number m of laminated silicon steel plates 7 forming the concave portions 9 is such that the number n of laminated silicon steel plates 7 on the convex portion 8 side is 2k less than the number m of laminated silicon steel plates 7 on the concave portion 9 side, in accordance with the thickness of the magnetic insulator 10. Therefore, according to the third embodiment, in a device formed by laminating silicon steel plates 7 and joined in an interlocking state between the convex portions 8 and the concave portions 9, it is possible to obtain the excellent effect of being able to provide an appropriate air gap for controlling the magnetic characteristics without increasing the size in the lamination direction.

[0033] The present invention is not limited to the above-described embodiments, and various changes are possible, for example, in the number of laminations n and m of the magnetic material, and the value k. Furthermore, the static induction device is not limited to a three-phase transformer, and may be a single-phase transformer other than three phase, and may also be applied to a reactor.

[0034] The above-described embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

Claims

DEPCT641. Stacked Axes (1,21) for a stationary induction machine which consists of upper and lower bracket sections (2,3,12,22,23) arranged by stacking a number of plate-shaped magnetic assemblies (7) and which consists of at least two leg sections (4,5,6,11,24,25,26) arranged by stacking a number of plate-shaped magnetic assemblies and connecting both ends of the upper and lower bracket sections vertically where the stacked axes (1,21) are arranged by butting the bracket and leg sections, where the connection surfaces of the bracket and leg sections are joined have protrusions (8,13) made of a number of magnetic assemblies and recesses (9,14) made of a number of magnetic assemblies alternatingly, and the bracket and leg sections are arranged to butt in such a way that the protrusions and recesses interlock with the magnetic insulator (10,15) Each plate-like structure is arranged in the butt joint between the protrusions and the recesses in a curved, folded shape that extends along the butt joint line, and an air gap is provided. In relation to the number of stacked magnetic components that form each protrusion and the number of stacked magnetic components that form each recess, the number of stacked magnetic components that form each protrusion is less than the number of stacked magnetic components that form each recess, corresponding to the thickness of the magnetic insulation.

2. Stacked core for a machine with static induction according to claim 1, where the butt joint between the frame and the legs is butt jointed in an angled state to create a frame-shaped joint.

3. Stacked core for a machine with static induction according to claim 1 or 2, where the dimensional dimensions of the magnetic insulation thickness correspond to the dimensional dimensions of the thickness of one magnetic component or correspond to an integer multiple of the dimensional dimensions of the thickness of one magnetic component.