Mounting structure for press blocks on a wound core of a stereoscopic dry-type open-type transformer

Abstract

Mounting structure for press blocks on a wound core of a stereoscopic dry-type open-type transformer, comprising three coils (1) arranged vertically and in a triangle, and press blocks (3), wherein an upper clamp (4) is arranged above the press blocks (3), and press bars (40) are arranged on the underside of the upper clamp (4) to press on the press blocks (3), wherein the upper clamp (4) is a hollow hexagonal frame, a press block fixing plate (41) is arranged in a central position of the hexagonal frame to press down on the press blocks below, a transverse plate (410) of the press block fixing plate (41) is curved upwards such that the horizontal height of the transverse plate (410) is higher than the upper end of an iron core of the corresponding coil, and press bars (40) for pressing the press blocks below (3) are arranged on the underside of the transverse plate 410, wherein an insulating ring (2) is arranged at the upper end of each of the coils (1) and at least one pressing block (3) for pressing the corresponding coil (1) is arranged on the upper side of each insulating ring (2), wherein the length of each pressing bar attached to the transverse plate (410) is greater than the length of each press bar attached to the upper clamp (40).

Description

Field of the invention:

[0001] The present invention relates to transformers, particularly to a fixing structure for fixing press blocks on a wound core of an open type dry type stereoscopic transformer.

[0002] A dry-type transformer with three coils arranged vertically and in a triangle and with compression blocks is known from US Pat. No. 8,659,382 B2. In this transformer, an upper clamp is arranged above the compression blocks, and compression rods are arranged on the underside of the upper clamp to press on the compression blocks.

[0003] Similar transformers are known from US 2014 / 0 002 229 A1 and CN 204 117 789 U. A similar transformer, which also features an insulating ring at the upper end of each coil, is known from US 8 659 382 B2. Rings composed of half rings are known from CN 201 259 835 Y.

[0004] An open-type dry-type transformer is also known from DE 22 26 114 B2. Another dry-type transformer is known from US Pat. No. 5,396,210 A.

[0005] A transformer with a hexagonal frame network is known from WO 2012 / 000 984 A1.

[0006] Further transformers are known from the documents CN 201 259 817 Y and US 2013 / 0 093 559 A1. Background of the invention:

[0007] It is well known that a stereoscopic dry-type open-type wound-core transformer has a non-packed structure; the iron cores and windings are arranged in a stereoscopic triangle; surrounding buffer blocks are directly secured by crimping a triangular frame. However, the crimping method for the triangular surface is particularly important. Not only should the crimping force be sufficient to ensure the short-circuit resistance of the transformer, but the crimping path must also be considered so as not to increase the insulation gaps between the coils. A common method currently involves placing a screw at the center of the triangular surface of the transformer and clamping the crimp blocks with a bottom clamp.This structure has the disadvantages that the tension screw is located at the center of the three coils, necessitating increased insulation spacing between the coils, and the insulation treatment of the tension screw has a significant impact on the quality of the transformer. Therefore, the task is to further optimize the fastening of the compression blocks in the triangular surface of the open-type transformer with a stereoscopically wound core.

[0008] The problem is solved by the fastening structure of patent claim 1. Further embodiments arise from the dependent patent claims. Brief description of the invention:

[0009] In order to solve the above problems, the present invention proposes a simply constructed fixing structure that can fix press blocks in the triangular area of ​​the transformer without increasing the insulation distance between the coils and ensuring the short-circuit withstand capacity of the transformer.

[0010] In order to solve the technical problems, the invention uses the following technical approach: The fastening structure for the pressing blocks on the wound core of an open-type stereoscopic dry-type transformer includes three coils arranged vertically; an insulation ring is arranged on the upper end of each of the coils; a pressing block serving to press the corresponding coil is arranged on top of each insulation ring; an upper clamp is arranged above the pressing blocks; pressing rods for pressing the pressing blocks are arranged on the underside of the upper clamp.

[0011] A further development of the technical concept provides that four press blocks are arranged accordingly on each of the coils, the four press blocks are evenly distributed on the upper side of the corresponding insulation ring and the angle enclosed between two adjacent press blocks is 90°.

[0012] A further development of the technical concept provides for each insulation ring to be composed of two semicircular insulation half-rings. The press blocks press on the joint of the corresponding two semicircular insulation half-rings.

[0013] According to the invention, the upper clamp is a hollow hexagonal framework. A press block fixing plate for pressing the underlying press blocks is arranged in the center position of the hexagonal framework. A cross plate of the press block fixing plate curves upwards so that the horizontal height of the cross plate is higher than that of the upper end of an iron core of each coil. The lower surface of the cross plate is provided with press bars for pressing the underlying press blocks.

[0014] In addition, the length of each pressing rod attached to the cross plate is greater than the length of each pressing rod attached to the upper clamp.

[0015] The fastening structure has the advantage that the upper clamp presses on the pressing blocks, and then the pressing blocks press on the coils to prevent the coils from loosening, thus ensuring the coils' impact resistance. Furthermore, the pressing blocks that press on the coils do not need to be clamped with a lower clamp using a screw. As a result, the phase spacing between the three coils is not increased, ensuring that the insulation distance between the coils does not increase. Furthermore, four pressing blocks are evenly distributed on each coil. This evenly distributes the load on the coils, allowing for better crimping. Short description of the drawings:

[0016] A further explanation of the invention is given in detail below with reference to the attached drawings and the embodiments. Fig. Figure 1 is a schematic representation of the structure of the invention. Fig. 2 is a drawing of an upper bracket of the invention. Fig. 3 is a drawing of a press block fixing plate of the invention. Detailed description of the implementation examples:

[0017] The Fig.1 to 3 illustrate a fixing structure for press blocks on a wound core of an open-type stereoscopic dry-type transformer with three coils 1 arranged vertically. The three coils 1 are arranged in a triangle. An insulation ring 2 is arranged on the upper end of each of the coils. A press block 3, which serves to press the corresponding coil, is arranged on top of each insulation ring 2. The insulation rings 2 essentially serve to press the coils 1. Since the coils are arranged stereoscopically, each insulation ring 2 is composed of two halves to facilitate assembly. In the exemplary embodiment, each insulation ring 2 is preferably composed of two semicircular insulation half-rings. The press blocks press the junction or overlap of the two corresponding semicircular insulation half-rings. An upper clamp 4 is arranged above the press blocks 3.Press rods 40 for pressing the press blocks are arranged on the underside of the upper clamp 4.

[0018] For example, the upper clamp 4 presses on the compression blocks 3. The compression blocks 3 then press on the coils 1, preventing the coils 1 from loosening and ensuring their short-circuit resistance. Furthermore, the compression blocks 3, which press on the coils 1, do not need to be loaded with a lower clamp using a screw. Consequently, the phase spacing between the three coils is not maintained, ensuring that the insulation distance between the coils does not increase.

[0019] To make the pressure exerted by the pressing blocks 3 on the coils 1 more uniform, four pressing blocks are preferably arranged on each coil 1. The four pressing blocks are evenly distributed on the upper side of the corresponding insulation ring 2. The enclosed angle between two adjacent pressing blocks is 90°. Because the four pressing blocks are evenly distributed on a coil 1, a more uniform pressure is applied to the upper end of each coil 1. This prevents tilting and thus ensures the pressing effect of the pressing blocks 3.

[0020] To facilitate manufacturing, processing, and assembly, the upper bracket 4 is a hollow hexagonal framework, with a press-block fixing plate 41 arranged at the center of the hexagonal framework to press the press blocks 3 located thereunder. In the embodiment, the press-block fixing plate 41 can be fixed to the upper bracket 4 by welding or by means of a screw. A cross plate 410 of the press-block fixing plate 41 bulges upward, so that the horizontal height of the cross plate 410 is greater than that of the upper end of an iron core of each coil. Press bars for loading the press blocks 3 located thereunder are attached to the underside of the cross plate 410. The above-mentioned press-block fixing plate 41 can be shaped to suit the size of the transformer by bending and welding steel plates or by welding angle iron.To ensure the pressing effect of the press block fixing plate 41 on the press blocks 3 arranged below it, the length of each press rod attached to the cross plate 410 is preferably greater than the length of each press rod attached to the upper clamp 4. In the exemplary embodiment, the size of each of the aforementioned press rods is determined according to actual requirements. Depending on given requirements, press (screw) rods with a comparatively large diameter can be selected so that the press blocks 3 can be advanced more effectively and the pressing effect of the press blocks 3 on the coils 1 is ensured.

[0021] Since a regular triangular surface is formed by surrounding the three coils 1, a regular triangle is also formed in the central surface of the cross plate 410 of the press block fixing plate 41. Three corners of the regular triangle are each provided with press rods to press the underlying press blocks 3. The three press blocks 3 arranged under the three corners of the regular triangle are each pressed against the three coils 1.

Claims

[1] A fastening structure for press blocks on a wound core of a stereoscopic dry-type transformer of open type, comprising three coils (1) arranged vertically and in a triangle, and press blocks (3), an upper clamp (4) being arranged above the press blocks (3), and press rods (40) being arranged on the underside of the upper clamp (4) to press on the press blocks (3), wherein the upper clamp (4) is a hollow hexagonal framework, a press block fixing plate (41) is arranged in a middle position of the hexagonal framework to press on the underlying press blocks, a cross plate (410) of the press block fixing plate (41) is curved upwards such that the horizontal height of the cross plate (410) is higher than the upper end of an iron core of the corresponding coil, and press rods (40) for pressing the underlying press blocks (3) are arranged on the underside of the cross plate 410, wherein an insulation ring (2) is arranged at the upper end of each of the coils (1) and at least one pressing block (3) for pressing the corresponding coil (1) is arranged on the upper side of each insulation ring (2), wherein the length of each pressing bar attached to the cross plate (410) is greater than the length of each pressing rod attached to the upper clamp (40). [2] A mounting structure for press blocks on a wound core of an open-type stereoscopic dry transformer according to claim 1, characterized by that four pressing blocks (3) are arranged correspondingly on each of the coils (1), wherein the four pressing blocks are evenly distributed on the upper side of the corresponding insulation ring (2) and wherein an angle of 90° is included between adjacent pressing blocks (3). [3] A mounting structure for press blocks on a wound core of an open-type stereoscopic dry transformer according to claim 1 or 2, characterized by that each insulation ring (2) is composed of two semicircular insulation half-rings and press blocks (3) press on the connection of the two semicircular insulation half-rings.

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