A method of replacing a transformer low side bushing and a fall arrest fastener

Abstract

The application provides a transformer low-voltage side bushing replacement method and a falling prevention fastener, belonging to the technical field of transformer maintenance, and comprising: a standardized operation process of loosening the nut, pulling the first guide rope to make the nut slide out, replacing the bushing, pulling the first guide rope to guide the nut back, and tightening the nut. After loosening the nut, the nut is moved out by pulling the first guide rope, avoiding the risk of the nut being suspended in the oil tank or temporarily placed and falling into the oil tank. After replacing the bushing, the same guide rope serves as both a falling prevention rope and a guide structure, enabling the nut to accurately return to the bolt tail along a predetermined path without the need for manual alignment in the dim and narrow oil tank. Compared with the disadvantage that the operator needs to feel the position of the bolt and the nut by touch, which easily leads to secondary falling of the nut, the application realizes a closed-loop operation of controllable moving out and controllable returning of the nut, reduces the operation failure rate and psychological burden, and the bushing replacement does not depend on special tools or high-precision equipment, and has strong operability and promotion value.

Description

Technical Field

[0001] This application belongs to the field of transformer maintenance technology, specifically relating to a method for replacing the low-voltage side bushing of a transformer and a fall-prevention fastener. Background Technology

[0002] The low-voltage side bushing of a transformer is an important insulation and fixing component of an oil-immersed transformer. When the bushing has defects such as cracks or damage, it needs to be replaced. During replacement, maintenance personnel need to open the manhole on the transformer tank, reach into the tank, and disassemble and install the bolts and nuts connecting the bushing terminals to the winding lead terminals.

[0003] Due to the confined space of the manhole and the dim lighting inside the oil tank, operators are highly susceptible to accidentally dropping small parts such as bolts, nuts, or washers into the tank during disassembly and assembly. Once a part falls, it is usually necessary to drain the transformer oil and lift the casing to retrieve it, significantly increasing maintenance workload, prolonging power outages, and causing substantial economic losses. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] In view of this, according to an embodiment of this application, a method for replacing a transformer low-voltage side bushing is proposed. This method is based on a transformer low-voltage side bushing anti-fall fastener, which includes: Bolts pass through the low-voltage side bushing terminals and the winding lead terminals inside the tank of the transformer. Nuts are used in threaded connections with bolts. The first guide rope has its first end connected to the first end of the bolt, and its second end extends out of the oil tank. The second guide rope has its first end connected to the second end of the bolt, and its second end extends out of the oil tank. The methods for replacing the low-voltage side bushing of a transformer include: Loosen the nut and remove it from the bolt; Pull the first guide rope to make the nut slide along the first guide rope to the outside of the oil tank; Replace the low-voltage side bushing of the transformer; Pull the first guide rope to pull the nut from the outside of the oil tank to the bolt; Tighten the nut to secure the low-voltage side bushing of the transformer.

[0006] In one feasible implementation, the transformer low-voltage side bushing anti-fall fastener further includes: The first threading part is located at the first end of the bolt and is detachably connected to the bolt. The first guide rope is attached to the first threading part. The second threading part is located at the second end of the bolt and is detachably connected to the bolt. The second guide rope is attached to the second threading part.

[0007] In one feasible implementation, the transformer low-voltage side bushing anti-fall fastener further includes: The first threaded hole is located at the tail of the bolt and is coaxial with the bolt. The side wall of the first threading part is provided with an external thread, the first end of the first threading part is threaded to the bolt through the first threaded hole, and the first guide rope is connected to the second end of the first threading part. The second threaded hole is located on the head of the bolt and is arranged coaxially with the bolt. The second threaded part has an external thread on its side wall. The first end of the second threaded part is threaded to a bolt through a second threaded hole. The second guide rope is connected to the second end of the second threaded part.

[0008] In one feasible implementation, the method for replacing the low-voltage side bushing of a transformer further includes: Use a bench drill to drill holes on both ends of the bolt; Use a tap to tap the two holes to form the first threaded hole and the second threaded hole; Screw the first threaded part into the first threaded hole, tie one end of the first guide rope to the first threaded part, and lead the other end of the first guide rope out of the oil tank. Screw the second threaded part into the second threaded hole, tie one end of the second guide rope to the second threaded part, and lead the other end of the second guide rope out of the oil tank.

[0009] In one feasible implementation, the method for replacing the low-voltage side bushing of a transformer further includes: Connect the disassembly and assembly tool to the first guide rope, and place the disassembly and assembly tool outside the oil tank when the nut slides.

[0010] In one feasible implementation, the method for replacing the low-voltage side bushing of a transformer further includes: Connect one end of the third guide rope to the disassembly and assembly tool, and connect the other end of the third guide rope to the operator's wrist or a fixed point outside the fuel tank.

[0011] In one feasible implementation, the transformer low-voltage side bushing anti-fall fastener further includes: A gasket is fitted onto the bolt and positioned between the nut and the sleeve terminal.

[0012] In one feasible implementation, the replacement of the transformer low-voltage side bushing includes the following steps prior to the following: Remove the gasket from the bolt and pull the first guide rope to slide the gasket along the first guide rope to the outside of the oil tank.

[0013] In one feasible implementation, the low-voltage side bushing of the transformer is replaced, followed by the step of: Pull the first guide rope to pull the gasket from the outside of the oil tank to the bolt.

[0014] In one feasible implementation, the method for replacing the low-voltage side bushing of a transformer further includes: When disassembling the nut and washer, move the nut and washer out of the oil tank synchronously along the first guide rope; When installing nuts and washers, insert the washers and nuts sequentially onto the first guide rope, and pull the first guide rope to simultaneously pull the washers and nuts onto the bolt.

[0015] The method for replacing the low-voltage side bushing of a transformer and the anti-fall fastener disclosed in this application have the following advantages compared with the prior art: The transformer low-voltage side bushing anti-fall fastener provided in this application includes a bolt, a nut, a first guide rope, and a second guide rope. By independently setting the first and second guide ropes at both ends of the bolt, active anti-fall protection is provided for the bolt and nut. The first guide rope is fixed to the tail of the bolt and passes through the nut to prevent the nut from falling off the bolt tail due to gravity or hand shaking after unscrewing. The second guide rope is fixed to the head of the bolt to prevent the bolt from slipping out of the terminal hole and falling into the bottom of the oil tank after the nut is removed. Thus, the first and second guide ropes, each independent yet working together, form a physical constraint on the entire process of disassembling and assembling the transformer low-voltage side bushing fastener. Unlike the existing technology that relies solely on the operator's skill to prevent fasteners from falling, which is purely dependent on human experience, this application completely eliminates the high-risk passive situation of fasteners falling into the oil tank in traditional operations. During the process of removing the nut, the bolt is originally held in the connection hole of the two terminals by the clamping force of the nut. Once the nut is loosened and removed, the bolt will lose axial constraint and will only maintain its position by the small friction between the bolt and the connection hole. In situations where the operating space inside the manhole is confined and the operator's arm movements are difficult to control precisely, bolts can easily slip out of the connection hole due to accidental contact or gravity, falling to the bottom of the tank. A second guide rope, attached to the bolt head, suspends the bolt inside the tank even if it slips out, preventing it from falling to the bottom and becoming difficult to retrieve. When the bolt needs to be completely removed for sleeve replacement, the operator can pull the second guide rope to slowly pull the bolt out of the connection hole to the outside of the tank. After the new sleeve is installed, the operator can pull the first guide rope again to move the bolt inside the tank, guiding it back to the connection holes of the two terminals. This eliminates the need for manual alignment in the dimly lit tank; the operator can adjust the bolt's position and tilt angle from outside the tank by pulling and releasing the first and second guide ropes, aligning the bolt's axis with the axes of the two terminal connection holes for successful installation.

[0016] The transformer low-voltage side bushing replacement method provided in this application adopts a standardized operating procedure of loosening the nut, pulling the first guide rope to slide the nut out, replacing the bushing, pulling the first guide rope to bring the nut back, and tightening the nut. After loosening the nut, pulling the first guide rope to move the nut out avoids the risk of the nut being suspended in the oil tank or falling into the oil tank due to temporary placement. After replacing the bushing, the same guide rope serves as both a fall arrest rope and a guiding structure, allowing the nut to accurately return to the bolt tail along a predetermined path, eliminating the need for manual alignment in the dim and confined oil tank. Compared to the drawbacks of requiring operators to rely on touch to locate the bolt and nut, which easily leads to the nut falling off again, this application achieves a closed-loop operation of controllable nut removal and controllable return, effectively reducing the operational error rate and psychological burden. At the same time, bushing replacement does not rely on special tools or high-precision equipment; it can be completed with an ordinary wrench and two guide ropes, making it highly operable on-site and worthy of widespread application. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic structural diagram of a transformer low-voltage side bushing anti-fall fastener according to an embodiment of this application; Figure 2 A schematic flowchart illustrating the steps of a transformer low-voltage side bushing replacement method according to an embodiment of this application; in, Figure 1 The correspondence between the reference numerals and component names in the attached drawings is as follows: 10. Bolt; 11. Nut; 12. First guide rope; 13. Second guide rope; 14. First threading part; 15. Second threading part; 16. Second threaded hole; 17. Washer. Detailed Implementation

[0018] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0020] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0021] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0022] like Figure 1 and Figure 2 As shown in the embodiments of this application, a method for replacing a transformer low-voltage side bushing is proposed. This method is based on a transformer low-voltage side bushing anti-fall fastener, which includes: a bolt 10, a nut 11, a first guide rope 12, and a second guide rope 13. The bolt 10 passes through the transformer low-voltage side bushing terminal and the winding lead terminal inside the oil tank. The nut 11 is threadedly connected to the bolt 10. The first end of the first guide rope 12 is connected to the first end of the bolt 10, and the second end of the first guide rope 12 extends out of the oil tank. The first end of the second guide rope 13 is connected to the second end of the bolt 10, and the second end of the second guide rope 13 extends out of the oil tank. The methods for replacing the low-voltage side bushing of a transformer include: Step 100: Loosen nut 11 and remove nut 11 from bolt 10; Step 200: Pull the first guide rope 12 to slide the nut 11 along the first guide rope 12 to the outside of the oil tank; replace the low-voltage side bushing of the transformer; Step 300: Pull the first guide rope 12 to pull the nut 11 from the outside of the oil tank to the bolt 10; Step 400: Tighten nut 11 to secure the low-voltage side bushing of the transformer.

[0023] The transformer low-voltage side bushing anti-fall fastener provided in this application includes a bolt 10, a nut 11, a first guide rope 12, and a second guide rope 13. By independently setting the first guide rope 12 and the second guide rope 13 at both ends of the bolt 10, active anti-fall protection is provided for the bolt 10 and the nut 11. The first guide rope 12 is fixed to the tail of the bolt 10 and passes through the nut 11 to prevent the nut 11 from falling off the tail of the bolt 10 due to gravity or hand shaking after unscrewing. The second guide rope 13 is fixed to the head of the bolt 10 to prevent the bolt 10 from slipping out of the terminal hole and falling into the bottom of the oil tank after the nut 11 is removed. Thus, the first guide rope 12 and the second guide rope 13, each independent yet working together, form a physical constraint on the entire process of disassembling and assembling the transformer low-voltage side bushing fastener. Unlike the existing technology that relies solely on the operator's skill to prevent fasteners from falling, which is purely dependent on human experience, this application completely eliminates the high-risk passive situation of fasteners falling into the oil tank in traditional operations. During the disassembly of nut 11, bolt 10 is initially held within the connection holes of the two terminals by the clamping force of nut 11. Once nut 11 is loosened and removed, bolt 10 loses its axial constraint and is maintained in position only by the slight friction between bolt 10 and the connection hole. Given the limited operating space within the manhole and the difficulty in precisely controlling the operator's arm movements, bolt 10 is highly susceptible to slipping out of the connection hole due to accidental contact or gravity, and falling to the bottom of the tank. The second guide rope 13 is attached to the head of bolt 10. Even if bolt 10 slips out of the connection hole, the second guide rope 13 can suspend bolt 10 inside the tank, preventing it from falling to the bottom and becoming difficult to retrieve. When it is necessary to completely remove bolt 10 for sleeve replacement, the operator can pull the second guide rope 13 to slowly pull bolt 10 out of the connection hole to the outside of the oil tank. After the new sleeve is installed, the operator can pull the first guide rope 12 again to move bolt 10 inside the oil tank and guide bolt 10 back to the connection hole of the two terminals from the outside of the oil tank. There is no need to manually search for alignment in the dim oil tank. The operator can adjust the position and tilt angle of bolt 10 inside the oil tank by pulling and releasing the first guide rope 12 and the second guide rope 13 from the outside of the oil tank, so that the axis of bolt 10 is aligned with the axis of the connection hole of the two terminals, thus smoothly installing bolt 10.

[0024] The transformer low-voltage side bushing replacement method provided in this application adopts a standardized operating procedure of loosening the nut 11, pulling the first guide rope 12 to slide the nut 11 out, replacing the bushing, pulling the first guide rope 12 to bring the nut 11 back, and tightening the nut 11. After loosening the nut 11, pulling the first guide rope 12 to move the nut 11 out avoids the risk of the nut 11 falling into the oil tank while suspended or temporarily placed. After replacing the bushing, the same guide rope serves as both a fall arrest rope and a guiding structure, enabling the nut 11 to accurately return to the tail of the bolt 10 along a predetermined path, eliminating the need for manual alignment in the dimly lit and cramped oil tank. Compared to the drawbacks of requiring the operator to rely on touch to locate the bolt 10 and nut 11, which easily leads to the nut 11 falling off again, this application achieves a closed-loop operation of controllable removal and return of the nut 11, effectively reducing the operational error rate and psychological burden. Meanwhile, the sleeve replacement does not rely on special tools or high-precision equipment; it can be completed with a regular wrench and two guide ropes, making it highly operable on-site and worthy of widespread application.

[0025] The inventors discovered that, when dealing with the problem of fasteners falling during sleeve replacement operations, those skilled in the art typically approach the issue by improving operating tools or adding magnetic adsorption. However, this application employs a low-cost, flexible traction solution, achieving double-insurance anti-fall protection for both bolt 10 and nut 11 with a minimalist structure.

[0026] like Figure 1 As shown, in one feasible embodiment, the transformer low-voltage side bushing anti-fall fastener further includes: a first threaded portion 14 and a second threaded portion 15; the first threaded portion 14 is disposed at the first end of the bolt 10, the first threaded portion 14 is detachably connected to the bolt 10, and a first guide rope 12 is tied to the first threaded portion 14; the second threaded portion 15 is disposed at the second end of the bolt 10, the second threaded portion 15 is detachably connected to the bolt 10, and a second guide rope 13 is tied to the second threaded portion 15.

[0027] In this technical solution, a detachable threading part independent of the bolt 10 body is adopted. On the one hand, the threading part serves as a fixed base for the guide rope, which can be quickly disassembled and assembled without damaging the original function of the bolt 10. On the other hand, after the sleeve is replaced, the guide rope can be quickly removed by disassembling the threading part, and the bolt 10 is restored to its standard shape. This does not affect the normal use of the bolt 10 in subsequent working conditions. The threading part and the guide rope are easy to disassemble and assemble, and do not affect the reuse of the bolt 10.

[0028] like Figure 1As shown, in one feasible embodiment, the transformer low-voltage side bushing anti-fall fastener further includes: a first threaded hole and a second threaded hole 16; the first threaded hole is opened at the tail of the bolt 10 and is coaxially arranged with the bolt 10; the side wall of the first wire-passing part 14 is provided with an external thread, the first end of the first wire-passing part 14 is threadedly connected to the bolt 10 through the first threaded hole, and the first guide rope 12 is connected to the second end of the first wire-passing part 14; the second threaded hole 16 is opened at the head of the bolt 10 and is coaxially arranged with the bolt 10; the side wall of the second wire-passing part 15 is provided with an external thread, the first end of the second wire-passing part 15 is threadedly connected to the bolt 10 through the second threaded hole 16, and the second guide rope 13 is connected to the second end of the second wire-passing part 15.

[0029] This technical solution further provides a threaded connection method between the threaded part and the bolt 10. By opening the threaded hole on the end face and the head end face of the bolt 10, the self-locking characteristic of the threaded connection is utilized to ensure that the threaded part will not loosen during repeated pulling of the guide rope, thus improving structural reliability. By opening the threaded hole in the center of the end face of the bolt 10, the direction of the tension of the guide rope is basically coincident with the axis of the bolt 10. When pulling, the bolt 10 is subjected to uniform force, which is not easy to deviate and jam, ensuring the smooth sliding of the nut 11 along the guide rope. At the same time, the setting of the end face threaded hole avoids the threaded working section and the head force surface of the bolt 10, and does not affect the tightening torque bearing capacity and tensile strength of the bolt 10. This application achieves a balance between the anti-fall function and the mechanical properties of the bolt 10 by opening the end face threaded hole, thereby improving the reliability and stability of the connection between the guide rope and the fastener while maintaining the original function and strength of the fastener.

[0030] In one feasible implementation, the method for replacing the low-voltage side bushing of the transformer further includes: drilling holes on both ends of the bolt 10 using a bench drill; tapping the two holes to form a first threaded hole and a second threaded hole 16; screwing the first threaded part 14 into the first threaded hole, tying one end of the first guide rope 12 to the first threaded part 14, and leading the other end of the first guide rope 12 out of the oil tank; screwing the second threaded part 15 into the second threaded hole 16, tying one end of the second guide rope 13 to the second threaded part 15, and leading the other end of the second guide rope 13 out of the oil tank.

[0031] This technical solution provides a complete pre-treatment process, enabling the wiring part to be quickly adapted to bolts 10 of different specifications. The specifications of the transformer low-voltage side bushing bolts 10 vary depending on the transformer model, voltage level, and manufacturer. For the pre-treatment method of fasteners in this application, maintenance personnel only need a bench drill and tap to immediately open threaded holes and install the wiring part according to the actual bolt 10 size. The steps are simple, the operation threshold is low, and the pre-treatment time for a single bolt 10 can be controlled within a few minutes. Compared to the hours or even days required for oil draining and hood removal due to fasteners falling, the time and labor costs are extremely low. This transforms anti-fall fasteners from customized products into a standardized method that can be quickly implemented in any field, making it more practical and adaptable.

[0032] In one feasible implementation, the method for replacing the low-voltage side bushing of the transformer further includes: connecting the disassembly and assembly tool to the first guide rope 12, and placing the disassembly and assembly tool outside the oil tank when the nut 11 slides.

[0033] In this technical solution, the disassembly and assembly of the low-voltage side bushing of the transformer requires tools such as socket wrenches and extension rods. The handhole space is narrow, usually only allowing a single arm to reach in. During use, the tools are prone to slipping and falling into the oil tank. By connecting the tools to the first guide rope 12, the tools are suspended outside the oil tank when not in use. Under their own weight, the first guide rope 12 pulls the tail of the bolt 10, while the second guide rope 13 pulls the head of the bolt 10, preventing the bolt 10 from falling into the oil tank during bushing disassembly and assembly. This incorporates the bolt 10 anti-fall safety system into the fastener anti-fall safety system, allowing operators to focus on their work without worrying about the bolt 10 falling, reducing the psychological burden of operation and thus helping to improve work efficiency and safety.

[0034] In one feasible implementation, the method for replacing the low-voltage side bushing of the transformer further includes: connecting one end of the third guide rope to the disassembly and assembly tool, and connecting the other end of the third guide rope to a fixed point on the operator's wrist or outside the oil tank.

[0035] In this technical solution, by adding a third guide rope, the disassembly and assembly tools are simultaneously connected to the operator's wrist or an external fixing point on the fuel tank, forming a more reliable fall protection structure. Even if the first guide rope 12 breaks or comes loose unexpectedly, the third guide rope can still serve as a second line of defense to prevent the tools from falling.

[0036] like Figure 1 As shown, in one feasible embodiment, the transformer low-voltage side bushing anti-fall fastener further includes: a washer 17; the washer 17 is sleeved on the bolt 10, and the washer 17 is located between the nut 11 and the bushing terminal.

[0037] In this technical solution, in the low-voltage side bushing fastening structure of the transformer, the gasket 17 is located between the nut 11 and the bushing terminal. The gasket 17 plays an important role in distributing pressure, preventing scratches on the terminal surface, and compensating for fastening gaps. However, in actual operation, the gasket 17 is the component most easily overlooked in fall protection. Operators often focus their attention on the bolt 10 and the nut 11. The gasket 17 is small and lightweight, and once it slips off the tail of the bolt 10, it is extremely difficult to find and retrieve in the dimly lit oil tank. This application incorporates the gasket 17 into a fall protection structure shared with the nut 11. The gasket 17 and the nut 11 share the same guide rope, expanding the fall protection coverage without increasing the number of guide ropes.

[0038] In one feasible implementation, replacing the low-voltage side bushing of the transformer includes the steps of: removing the gasket 17 from the bolt 10 and pulling the first guide rope 12 to slide the gasket 17 along the first guide rope 12 to the outside of the oil tank.

[0039] This technical solution provides specific operating steps for disassembling the anti-fall device 17. The nut 11 and the washer 17 share the same guide rope but are operated at different times. During disassembly, the nut 11 is first slid out along the first guide rope 12, and then the washer 17 is removed from the tail of the bolt 10 and slid out along the same guide rope. This avoids the nut 11 and washer 17 potentially getting stuck on the threaded section of the bolt 10 due to mutual compression when pulling the guide rope, preventing them from sliding out smoothly. By first sliding out the nut 11 to release space, and then sliding out the washer 17, both the anti-fall effect of the nut 11 and the washer 17 are ensured, as well as the smoothness of operation.

[0040] In one feasible implementation, after replacing the low-voltage side bushing of the transformer, the process further includes the step of pulling the first guide rope 12 to pull the gasket 17 from the outside of the oil tank to the bolt 10.

[0041] In this technical solution, the installation process prioritizes the gasket 17 as an independent step, resulting in an installation sequence of gasket 17 first, followed by nut 11. After installing the new sleeve, the bolt 10 is inserted into the terminal hole. By sequentially pulling the gasket 17 and nut 11, once the gasket 17 is in place, the first guide rope 12 separates from the gasket 17. When the nut 11 slides subsequently, the first guide rope 12 only needs to overcome the friction of the nut 11 itself, making the pulling operation smoother. This avoids the risk of the gasket 17 being squeezed by the nut 11 during the pulling process, causing it to tilt, deviate, or get stuck, thus ensuring the reliability of the fastening structure installation.

[0042] In one feasible implementation, the method for replacing the low-voltage side bushing of the transformer further includes: when disassembling the nut 11 and the washer 17, moving the nut 11 and the washer 17 out of the oil tank simultaneously along the first guide rope 12; when installing the nut 11 and the washer 17, threading the washer 17 and the nut 11 sequentially onto the first guide rope 12, pulling the first guide rope 12, and simultaneously pulling the washer 17 and the nut 11 onto the bolt 10.

[0043] This technical solution further provides a synchronous traction operation procedure for the disassembly and installation of nut 11 and washer 17, improving work efficiency and ease of operation. Currently, during disassembly, nut 11 must be removed first, followed by washer 17. Operators must pull the first guide rope 12 twice, and adjust their hand position and re-grab the tool between each pull, which is particularly inconvenient in confined handholes. Since nut 11 and washer 17 are inserted into the first guide rope 12, a single pull allows washer 17 and nut 11 to slide together from bolt 10 to the outside of the oil tank, combining two independent removal actions into one. This saves disassembly time and reduces the number of arm movements required inside the oil tank, effectively reducing muscle fatigue and the risk of errors caused by repeated operations. From the installation process, the insertion sequence is that the gasket 17 is inserted first and the nut 11 is inserted later. However, the traction action of installation is carried out simultaneously, which not only ensures that the gasket 17 can be correctly installed in the predetermined position between the nut 11 and the terminal, but also simplifies the installation action, compressing the operation that originally required two independent tractions into one operation.

[0044] It should be noted that when the initial gap between the nut 11 and the washer 17 on the bolt 10 is sufficient and the surface of the first guide rope 12 is smooth, the synchronous pulling operation can maximize the work efficiency. When the initial gap between the nut 11 and the washer 17 on the bolt 10 is insufficient or the surface of the first guide rope 12 is not smooth, the operator can switch to the separate pulling mode to avoid jamming of the nut 11 and the washer 17, thus improving the adaptability to the site environment. It can be reliably applied in both new installations and maintenance scenarios of old transformers.

[0045] It will be readily understood by those skilled in the art that the above embodiments can be freely combined and superimposed without conflict.

[0046] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A method for replacing a low-voltage side bushing of a transformer, characterized in that, The transformer low-voltage side bushing replacement method is based on a transformer low-voltage side bushing anti-fall fastener, which includes: Bolts, which pass through the low-voltage side bushing terminals and the winding lead terminals inside the oil tank of the transformer; Nut, which is threadedly connected to the bolt; A first guide rope, the first end of which is connected to the first end of the bolt, and the second end of which extends out of the oil tank; A second guide rope, the first end of which is connected to the second end of the bolt, and the second end of which extends out of the oil tank; The method for replacing the low-voltage side bushing of the transformer includes: Loosen the nut and remove it from the bolt; Pull the first guide rope to make the nut slide along the first guide rope to the outside of the oil tank; Replace the low-voltage side bushing of the transformer; Pull the first guide rope to pull the nut from the outside of the oil tank to the bolt; Tighten the nut to secure the low-voltage side bushing of the transformer.

2. The method for replacing a low-voltage side bushing of a transformer according to claim 1, characterized in that, The transformer low-voltage side bushing anti-fall fastener also includes: A first threading part is disposed at the first end of the bolt, the first threading part is detachably connected to the bolt, and the first guide rope is tied to the first threading part. The second threading part is disposed at the second end of the bolt and is detachably connected to the bolt. The second guide rope is attached to the second threading part.

3. The method for replacing a transformer low-voltage side bushing according to claim 2, characterized in that, The transformer low-voltage side bushing anti-fall fastener also includes: A first threaded hole is formed at the tail of the bolt, and the first threaded hole is coaxially arranged with the bolt. The first threaded part has an external thread on its side wall. The first end of the first threaded part is threadedly connected to the bolt through the first threaded hole. The first guide rope is connected to the second end of the first threaded part. A second threaded hole is formed in the head of the bolt and is coaxially arranged with the bolt. The second threaded part has an external thread on its side wall. The first end of the second threaded part is threaded to the bolt through the second threaded hole. The second guide rope is connected to the second end of the second threaded part.

4. The method for replacing a low-voltage side bushing of a transformer according to claim 3, characterized in that, The method for replacing the low-voltage side bushing of the transformer also includes: Use a bench drill to drill holes on both ends of the bolt; Use a tap to tap the two holes to form the first threaded hole and the second threaded hole; Screw the first threaded part into the first threaded hole, tie one end of the first guide rope to the first threaded part, and lead the other end of the first guide rope out of the oil tank. Screw the second threaded part into the second threaded hole, tie one end of the second guide rope to the second threaded part, and lead the other end of the second guide rope out of the oil tank.

5. The method for replacing a low-voltage side bushing of a transformer according to claim 1, characterized in that, The method for replacing the low-voltage side bushing of the transformer also includes: Connect the disassembly and assembly tool to the first guide rope, and place the disassembly and assembly tool outside the oil tank when the nut slides.

6. The method for replacing a low-voltage side bushing of a transformer according to claim 1, characterized in that, The method for replacing the low-voltage side bushing of the transformer also includes: Connect one end of the third guide rope to the disassembly and assembly tool, and connect the other end of the third guide rope to the operator's wrist or a fixed point outside the fuel tank.

7. The method for replacing a low-voltage side bushing of a transformer according to claim 1, characterized in that, The transformer low-voltage side bushing anti-fall fastener also includes: A gasket, which is fitted onto the bolt and located between the nut and the sleeve terminal.

8. A method for replacing a low-voltage side bushing of a transformer according to claim 7, characterized in that, The replacement of the transformer low-voltage side bushing includes the following steps prior to the following: Remove the gasket from the bolt and pull the first guide rope to slide the gasket along the first guide rope to the outside of the oil tank.

9. A method for replacing a low-voltage side bushing of a transformer according to claim 7, characterized in that, The replacement of the low-voltage side bushing of the transformer further includes the following steps: Pull the first guide rope to pull the gasket from the outside of the oil tank to the bolt.

10. A method for replacing a low-voltage side bushing of a transformer according to claim 8 or 9, characterized in that, The method for replacing the low-voltage side bushing of the transformer also includes: When disassembling the nut and the washer, the nut and the washer are moved out of the oil tank synchronously along the first guide rope; When installing the nut and the washer, the washer and the nut are sequentially threaded onto the first guide rope, and the first guide rope is pulled to simultaneously pull the washer and the nut onto the bolt.

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