An improved insert for dry-type transformers

Abstract

The utility model discloses an improved embedded part for dry-type transformer, which comprises a cylindrical main body in the shape of a cylinder. Both ends of the cylindrical main body are provided with screw holes. The screw hole at one end is a first end screw hole, and the screw hole at the other end is a second end screw hole. Two hexagonal pieces are fixedly arranged around the cylindrical main body. The two hexagonal pieces are distributed at intervals, and each of the two hexagonal pieces has six end faces. The utility model cancels the design of a square long column, sets screw holes at both ends of the cylindrical main body, is easy to install, and can be directly welded without hanging copper, thereby simplifying the process and reducing the cost. Furthermore, two hexagonal pieces are additionally arranged around the cylindrical main body. The hexagonal planes provide tool clamping surfaces, increase the clamping area, and reliably fix the hexagonal pieces during welding. In addition, under the synergistic action of the angular structure of the hexagonal pieces and the double screw holes, the anti-rotation and anti-vibration capabilities of the embedded part are enhanced, and the welding points are ensured to be stable for a long time.

Description

Technical Field

[0001] This utility model relates to transformer inserts, and more particularly to an improved insert for dry-type transformers. Background Technology

[0002] In the field of dry-type transformer manufacturing, traditional inserts are cylindrical structures with a screw hole at one end and a rectangular post at the other. This design has the following drawbacks:

[0003] 1) Traditional inserts require pre-copper soldering for fixation during use, which is a complex process and increases manufacturing costs;

[0004] 2) The transition section between the square column and the cylindrical column is prone to friction with tools or mounting surfaces during installation, affecting the appearance and protective performance;

[0005] 3) The square column structure lacks an effective clamping surface, which makes it prone to displacement under vibration, resulting in uneven stress at the weld points and reducing connection reliability;

[0006] 4) The single-head screw hole design restricts the installation direction, requiring precise alignment of the screw hole direction, resulting in low operating efficiency and easy stress on the internal welding area due to rotation. Utility Model Content

[0007] To solve the above technical problems, the technical solution adopted by this utility model is: an improved insert for dry-type transformers.

[0008] To solve the above technical problems, the technical solution adopted by this utility model is: an improved insert for dry-type transformers, which includes a cylindrical body in the shape of a cylinder;

[0009] Both ends of the cylindrical body are provided with screw holes, the screw hole at one end is the first end screw hole, and the screw hole at the other end is the second end screw hole;

[0010] Two hexagonal pieces are fixedly arranged around the cylindrical body, with the two hexagonal pieces spaced apart, and each of the two hexagonal pieces has six end faces.

[0011] Preferably, the cylindrical body includes a core support, a transition layer, and a surface layer;

[0012] The transition layer is electrodeposited on the surface of the core support, and the surface layer is deposited on the surface of the transition layer.

[0013] Preferably, the transition layer is a copper-silver composite plating layer.

[0014] Preferably, the surface layer is a titanium nitride coating.

[0015] Preferably, the hexagonal piece has anti-slip texture on its end face.

[0016] Preferably, the first end screw hole is a screw hole that penetrates one end of the cylindrical body, and the thread inside the screw hole is a 45° angle thread.

[0017] Preferably, the second end screw hole is a screw hole that penetrates the other end of the cylindrical body, and the thread inside the screw hole is a 30° angle thread.

[0018] Preferably, guide chamfers are machined at the screw hole entrances of the first and second end screw holes.

[0019] This utility model discloses an improved insert for dry-type transformers, specifically an insert for internal fixing and installation within the transformer. Compared to traditional insert structures, it eliminates the square column design, providing screw holes at both ends of the cylindrical body for easy installation and direct welding without the need for copper plating, simplifying the process and reducing costs. Furthermore, two hexagonal pieces are added to the periphery of the cylindrical body, providing tool clamping surfaces through the hexagonal planes, increasing the clamping area and ensuring reliable fixation during welding. In addition, the synergistic effect of the hexagonal angular structure and the double screw holes enhances the insert's resistance to rotation and vibration, ensuring long-term stability of the weld joint. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram from one side view of the present invention.

[0021] Figure 2 This is a three-dimensional structural diagram from another perspective of the present invention.

[0022] Figure 3 This is a cross-sectional structural diagram of the present invention.

[0023] In the figure: 1. Cylindrical body; 2. First end screw hole; 3. Second end screw hole; 4. Hexagonal piece; 4a. End face; 5. Guide chamfer. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] This utility model discloses an improved insert for dry-type transformers, the overall structure of which is as follows: Figure 1 and Figure 2 As shown, it includes a cylindrical body 1 in the shape of a cylinder. Both ends of the cylindrical body 1 are provided with screw holes. For ease of description, the screw hole at one end is named the first end screw hole 2, and the screw hole at the other end is named the second end screw hole 3. Two hexagonal pieces 4 are provided on the cylindrical body 1. The two hexagonal pieces are distributed at intervals and each has six end faces 4a.

[0026] Among them, the cylindrical body 1 is the core support structure of the insert; for traditional dry-type transformers, using copper substrate as the core support structure has the disadvantage of poor service life; the improved insert of this novel uses gradient functional composite material to optimize the cylindrical body 1, and the cylindrical body 1 includes a core support, a transition layer and a surface layer.

[0027] The core support, serving as the core layer, is based on a copper matrix incorporating 0.5 wt% carbon nanotubes. The addition of carbon nanotubes enhances the fatigue resistance and wear resistance of the cylindrical body. Furthermore, carbon nanotubes possess excellent electrical conductivity (up to 10⁻⁶). 6 The conductivity (S / m) is improved by forming a continuous conductive network with the copper substrate.

[0028] A transition layer is electrodeposited on the surface of the core support, forming a solid coating. The transition layer is a copper-silver composite coating with a thickness of 50 μm and a silver content gradient increasing from 20% to 60%.

[0029] The surface layer is a titanium nitride coating, which is formed on the surface of the transition layer using atomic layer deposition (ALD). The thickness of the titanium nitride coating is 200 nm, which improves the resistance to arc ablation.

[0030] Therefore, through the optimized design of the composite substrate, the cylindrical body 1 greatly improves the conductivity and reduces heat generation. The composite coating reduces tip discharge and improves the resistance to arc erosion, thereby effectively improving the service life of the insert and transformer.

[0031] The two hexagonal pieces have the same structure, which is a hexagonal structure with six end faces 4a. The hexagonal pieces are fixed to the periphery of the cylindrical body 1, providing clamping surfaces and anti-rotation functions. Compared with traditional inserts, the setting of hexagonal pieces 4 increases the clamping and fixing surfaces, which can avoid damage to the welded structure caused by rotation after entering the mold and simultaneous rotation of the welding lines during the manufacturing process.

[0032] Preferably, anti-slip textures are provided on the end face 4a of the hexagonal component 4 to increase the clamping friction of the hexagonal component. For example, radial diamond knurling (tooth depth 0.1mm) is machined on the end face of the hexagonal component, combined with surface hard chrome plating (thickness 8μm) to form anti-slip textures.

[0033] like Figure 3 As shown, the first end screw hole 2 is a screw hole that penetrates one end of the cylindrical body 1. It adopts a low-angle thread design, preferably a 45° angle thread, which can effectively improve the shear strength of the gear connection section, thereby improving the service life.

[0034] The second end screw hole 3 is a screw hole that penetrates to the other end of the cylindrical body 1, forming a double threaded channel with the first end screw hole 2. It is preferable that the thread of the second end screw hole 3 is a 30° angle thread, which can improve tensile strength and improve the overall strength by using a transition thread method.

[0035] Relatively speaking, the thread at the first end of the screw hole is a large-angle thread, while the thread at the second end of the screw hole is a small-angle thread. The optimal angle combination is determined through finite element optimization to form an asymmetric thread design, ensuring the reliability of the screw hole connection.

[0036] Preferably, a 15° guide chamfer 5 is machined at the screw hole entrances of the first end screw hole 2 and the second end screw hole 3, and a special installation tool (internal hex wrench + guide sleeve) is used to reduce the risk of thread misalignment.

[0037] Furthermore, it should be noted that the cylindrical body 1 and the hexagonal part 4 are directly integrally formed using a multi-station cold heading machine, achieving a dimensional accuracy of IT8, thus reducing subsequent machining. After the cylindrical body 1 and the hexagonal part 4 are integrally formed, a transition layer and a surface layer are applied. Optional laser welding reinforcement is also available: the hexagonal part and the cylindrical body are welded using a fiber laser (800W power, 10ms pulse width) with a penetration depth of 0.5mm, achieving a surface roughness of Ra3.2 without the need for polishing after welding.

[0038] In addition, a low-cost anti-oxidation passivation + oil sealing process can be selected: the finished product is first passivated with benzotriazole to form a protective film, and then immersed in transformer oil (viscosity 32cSt), which has an anti-oxidation capability of up to 12 months during storage (6 months for traditional processes).

[0039] Therefore, the improved insert for dry-type transformers disclosed in this utility model provides axial support through the cylindrical body 1, and the threaded holes at both ends can be directly connected to bolts or welded parts without the need for copper plating. The internal thread structure effectively improves welding strength. The hexagonal part 4 provides a tool clamping surface through its planar end face structure, preventing rotational friction during installation. At the same time, the surface anti-slip texture design enhances the stability of the insert in contact with the mounting surface. The double-ended threaded holes with chamfered design support multi-directional welding, adapting to complex installation scenarios and improving process compatibility. Compared with the prior art, it has the following technical advantages:

[0040] 1) Copper-free soldering: The double-ended screw hole design allows direct connection to the soldering parts, eliminating the traditional copper plating process, simplifying the production process and reducing costs.

[0041] 2) Enhanced positioning: The hexagonal fitting provides a clamping surface and increases the clamping area. Furthermore, the hexagonal fitting features a composite anti-slip texture, increasing the contact area with the transformer resin and improving the insert's reliability.

[0042] 3) Adaptability: The circular screw hole supports welding in multiple directions, reducing installation direction restrictions and improving operating efficiency and applicability.

[0043] 4) Vibration and rotation resistance: The angular structure of the hexagonal component and the double screw holes work together to enhance the stability and reliability of the insert in dynamic environments.

[0044] 5) Improved substrate material and coating: The cylindrical body adopts a composite substrate, which greatly improves the conductivity and reduces heat generation. The composite coating reduces tip discharge, improves arc erosion resistance, and significantly improves the service life of inserts and transformers.

[0045] The above embodiments are not intended to limit the present utility model, nor is the present utility model limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the technical solution of the present utility model are also within the protection scope of the present utility model.

Claims

1. An improved insert for dry-type transformers, characterized in that: It includes a cylindrical body (1) in the shape of a cylinder; Both ends of the cylindrical body (1) are provided with screw holes, one end of which is the first end screw hole (2) and the other end of which is the second end screw hole (3). Two hexagonal pieces (4) are fixedly arranged on the cylindrical body (1). The two hexagonal pieces (4) are distributed at intervals, and each of the two hexagonal pieces (4) has six end faces (4a).

2. The improved insert for dry-type transformers according to claim 1, characterized in that: The cylindrical body (1) includes a core support, a transition layer and a surface layer; The transition layer is electrodeposited on the surface of the core support, and the surface layer is deposited on the surface of the transition layer.

3. The improved insert for dry-type transformers according to claim 2, characterized in that: The transition layer is a copper-silver composite plating layer.

4. The improved insert for dry-type transformers according to claim 3, characterized in that: The surface layer is a titanium nitride coating.

5. The improved insert for dry-type transformers according to claim 1, characterized in that: Anti-slip texture is provided on the end face (4a) of the hexagonal piece (4).

6. The improved insert for dry-type transformers according to claim 1, characterized in that: The first end screw hole (2) is a screw hole that penetrates one end of the cylindrical body (1), and the thread inside the screw hole is a 45° angle thread.

7. The improved insert for dry-type transformers according to claim 6, characterized in that: The second end screw hole (3) is a screw hole that penetrates the other end of the cylindrical body (1), and the thread inside the screw hole is a 30° angle thread.

8. The improved insert for dry-type transformers according to claim 1 or 7, characterized in that: A guide chamfer (5) is machined at the screw hole entrance of the first end screw hole (2) and the second end screw hole (3).

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