Oil-immersed transformer bushing head device preventing gas backflow
The sealed design of the oil conservator and conductive pipe assembly solves the problem of air backflow at the bushing head of the oil-immersed transformer, achieving oil level stability and preventing partial discharge, simplifying the structure and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIANGSU SIYUAN HERTZ TRANSFORMER
- Filing Date
- 2022-10-09
- Publication Date
- 2026-07-14
AI Technical Summary
In traditional oil-immersed transformers, air can flow back into the bushing head during transportation, causing partial discharge and, in severe cases, breakdown discharge. Existing solutions are complex, bulky, costly, and lack gas backflow prevention capabilities.
It adopts an oil conservator, porcelain sleeve and conductive tube structure, combined with components such as tightening lower pressure plate, tightening upper pressure plate, spring, tightening nut and locking bolt, and prevents air backflow through sealed connection and thread design, so as to maintain stable oil level.
The oil level is stable during normal operation of the transformer, which does not affect normal operation. During horizontal transportation, it prevents air from entering the bushing, simplifies the structure, reduces costs, and avoids partial discharge.
Smart Images
Figure CN115346778B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of oil-immersed transformer technology, and more particularly to an oil-immersed transformer bushing head device for preventing gas backflow. Background Technology
[0002] Oil-immersed transformer bushings are used in power systems for electrical connection and mechanical support between power transformers and transmission lines, serving functions such as power transmission, electrical insulation, and mechanical support. Traditional oil-immersed transformer bushings typically have a certain amount of air at the head. When the product is transported horizontally, this air can flow back into the middle of the bushing. When the product is installed vertically again, air bubbles can easily form in the middle, causing partial discharge and, in severe cases, breakdown.
[0003] like Figure 1 The few products shown have an expander installed in the middle of the flange. This expander compensates for the oil level, ensuring no air is present at the casing head, thus solving the problem of gas backflow from the casing head into the middle of the casing. For example... Figure 2 Most of the products shown adopt this structure. There is some air at the head of the sleeve. When the product is placed horizontally, the air at the head can flow into the middle of the sleeve through the gap between the spring clamping device and the conductive tube.
[0004] The two solutions mentioned above have the following disadvantages: 1) The structure is relatively complex, bulky, and large in size, making installation inconvenient; 2) The product cost is relatively high; 3) They do not have the function of preventing gas reflux. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a bushing head device for preventing gas backflow in oil-immersed transformers. This device can solve the problem that, during the transportation of ordinary oil-immersed transformers, air at the head can flow back into the middle of the bushing. When the product is installed vertically again, air bubbles are easily generated in the middle, causing partial discharge of the product, and in severe cases, it can lead to product breakdown discharge.
[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: an oil-immersed transformer bushing head device for preventing gas backflow, comprising an oil conservator, a porcelain bushing, and a conductive tube; the bottom end of the oil conservator is connected to the top tube of the porcelain bushing, the conductive tube is arranged vertically inside the porcelain bushing and the oil conservator, and one end of the conductive tube extends out of the oil conservator; a transformer oil cavity communicating with the inner cavity of the oil conservator is formed between the outer wall of the conductive tube and the inner wall of the porcelain bushing; characterized in that it includes a lower clamping plate, an upper clamping plate, a spring, a clamping nut, and a locking bolt;
[0007] The conductive tube has a cylindrical structure, and a section of the conductive tube located inside the oil tank has threads on its outer contour, and the threaded section of the conductive tube is located above the tightening pressure plate.
[0008] The tightening lower pressure plate is installed inside the oil tank and has a ring-shaped structure. The tightening lower pressure plate is nested on the conductive pipe and is placed horizontally on the lower surface of the inner wall of the oil tank. The inner contour of the tightening lower pressure plate is sealed to the outer wall of the conductive pipe. The bottom end of the tightening lower pressure plate is sealed to the lower surface of the inner wall of the oil tank. The tightening lower pressure plate is provided with an L-shaped oil passage, and the two ends of the oil passage are located on the outer surface and the lower surface of the tightening lower pressure plate, respectively. A countersunk threaded hole is opened on the upper surface of the tightening lower pressure plate.
[0009] The upper clamping plate is positioned above the lower clamping plate and inside the oil tank; the upper clamping plate has a ring structure and a pair of bolt holes are symmetrically arranged around the central hole of the upper clamping plate; the upper clamping plate is nested on the conductive tube and a gap is left between the upper clamping plate and the outer wall of the conductive tube.
[0010] The locking bolt passes through the bolt hole of the upper clamping plate, and the bottom end of the locking bolt is connected to the countersunk thread hole on the lower clamping plate; the spring is nested on the locking bolt and located between the upper clamping plate and the lower clamping plate; a connecting nut is provided at the top of the locking bolt and connected to the locking bolt to press the upper clamping plate against the top of the spring;
[0011] The tightening nut is positioned above the upper tightening plate, and the tightening nut engages with the threaded section on the conductive tube to press the lower tightening plate against the bottom surface of the inner wall of the oil tank.
[0012] Furthermore, a first sealing groove is provided on the inner wall of the central opening of the tightening lower pressure plate, and a second sealing groove is provided at the junction of the lower surface of the tightening lower pressure plate and the lower surface of the inner wall of the oil tank, and sealing rubber is provided in both the first sealing groove and the second sealing groove.
[0013] The advantages of this invention are:
[0014] 1) In this invention, when the transformer is running vertically, the transformer oil in the oil conservator and the transformer oil in the porcelain bushing are connected as a whole. When the product expands and contracts with temperature, the oil level can still rise and fall normally without affecting the normal operation of the product. When the product is transported horizontally, because the oil inlet on the tightening lower pressure plate is higher than the edge of the inner diameter of the porcelain bushing, the oil in the porcelain bushing cannot flow back into the oil conservator, and the air in the oil conservator cannot enter the porcelain bushing. This achieves the function of preventing gas from the bushing head from entering the middle of the porcelain bushing during horizontal transportation. It does not require changing the main structure and size of the existing porcelain bushing; it only requires slight changes to the size and structure of some parts, making it simple to implement and low in cost. Attached Figure Description
[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0016] Figure 1 This is a schematic diagram of a conventional structure that uses an expander for oil level compensation and to prevent gas backflow.
[0017] Figure 2 This is a commonly used bushing head structure for preventing gas backflow in oil-immersed transformers.
[0018] Figure 3 This invention relates to a bushing head device for preventing gas backflow in an oil-immersed transformer. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.
[0021] like Figure 3 The illustrated oil-immersed transformer bushing head device for preventing gas backflow includes an oil conservator 1, a porcelain bushing 2, and a conductive tube 3. The bottom end of the oil conservator 1 is connected to the top tube of the porcelain bushing 2. The conductive tube 3 is vertically arranged inside the porcelain bushing 2 and the oil conservator 1, with one end of the conductive tube 3 extending out of the oil conservator 1. A transformer oil cavity is formed between the outer wall of the conductive tube 3 and the inner wall of the porcelain bushing, which is in communication with the inner cavity of the oil conservator 1. The device includes a lower clamping plate 4, an upper clamping plate 5, a spring 6, a clamping nut 7, and a locking bolt 8.
[0022] The conductive tube 3 has a cylindrical structure. A section of the conductive tube 3 located inside the oil tank has threads on its outer contour, and the threaded section of the conductive tube 3 is located above the tightening pressure plate 4.
[0023] The tightening lower pressure plate 4 is installed inside the oil tank and has a ring structure. The tightening lower pressure plate 4 is nested on the conductive tube 3 and is placed horizontally on the lower surface of the inner wall of the oil tank 1. The inner contour of the tightening lower pressure plate 4 is sealed to the outer wall of the conductive tube. The bottom end of the tightening lower pressure plate 4 is sealed to the lower surface of the inner wall of the oil tank 1. The tightening lower pressure plate 4 is provided with an L-shaped oil passage 41, and the two ends of the oil passage 41 are located on the outer surface and the lower surface of the tightening lower pressure plate 4, respectively. A countersunk threaded hole is opened on the upper surface of the tightening lower pressure plate 4.
[0024] The upper clamping plate 5 is positioned above the lower clamping plate 4 and inside the oil tank 1; the upper clamping plate 5 has a ring structure and a pair of bolt holes are symmetrically arranged around the center hole of the upper clamping plate 5; the upper clamping plate 5 is nested on the conductive tube 3 and a gap is left between the upper clamping plate 5 and the outer wall of the conductive tube 3.
[0025] The locking bolt 8 passes through the bolt hole of the upper clamping plate 5, and the bottom end of the locking bolt 8 is connected to the countersunk thread hole on the lower clamping plate 4; the spring 6 is nested on the locking bolt 8 and located between the upper clamping plate 5 and the lower clamping plate; the top of the locking bolt 8 is provided with a connecting nut that is connected to the locking bolt 8 to press the upper clamping plate 5 against the top of the spring.
[0026] The tightening nut 7 is positioned above the tightening upper pressure plate, and the tightening nut 7 engages with the threaded section on the conductive tube 3 to press the tightening lower pressure plate 4 against the bottom surface of the inner wall of the oil tank 1.
[0027] A first sealing groove is provided on the inner wall of the center opening of the tightening lower pressure plate 4, and a second sealing groove is provided at the junction of the lower surface of the tightening lower pressure plate 4 and the lower surface of the inner wall of the oil tank 1. Both the first sealing groove and the second sealing groove are provided with sealing rubber.
[0028] The working principle of this invention is as follows: When the transformer is running vertically, the transformer oil in the oil conservator and the transformer oil in the porcelain bushing are connected as a whole. During thermal expansion and contraction, the oil level in the product can still rise and fall normally without affecting the normal operation of the product. When the product is transported horizontally, because the oil inlet on the tightening lower pressure plate is higher than the edge of the inner diameter of the porcelain bushing, the oil in the porcelain bushing cannot flow back into the oil conservator, and the air in the oil conservator cannot enter the porcelain bushing. This achieves the function of preventing gas from the bushing head from entering the middle of the porcelain bushing during horizontal transportation. It does not require changing the main structure and size of the existing porcelain bushing; it only requires slight changes to the size and structure of some parts, making it simple to implement and low in cost.
[0029] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.
Claims
1. A bushing head device for preventing gas backflow in an oil-immersed transformer, comprising an oil conservator, a porcelain bushing, and a conductive tube; the bottom end of the oil conservator is connected to the top tube of the porcelain bushing, the conductive tube is vertically disposed within the porcelain bushing and the oil conservator, and one end of the conductive tube extends out of the oil conservator; a transformer oil cavity communicating with the inner cavity of the oil conservator is formed between the outer wall of the conductive tube and the inner wall of the porcelain bushing; characterized in that: Includes a lower clamping plate, an upper clamping plate, a spring, a clamping nut, and a locking bolt; The conductive tube has a cylindrical structure, and a section of the conductive tube located inside the oil tank has threads on its outer contour, and the threaded section of the conductive tube is located above the tightening pressure plate. The tightening lower pressure plate is installed inside the oil tank and has a ring-shaped structure. The tightening lower pressure plate is nested on the conductive pipe and is placed horizontally on the lower surface of the inner wall of the oil tank. The inner contour of the tightening lower pressure plate is sealed to the outer wall of the conductive pipe. The bottom end of the tightening lower pressure plate is sealed to the lower surface of the inner wall of the oil tank. The tightening lower pressure plate is provided with an L-shaped oil inlet, and the two ends of the oil inlet are located on the outer surface and the lower surface of the tightening lower pressure plate, respectively. A countersunk threaded hole is opened on the upper surface of the tightening lower pressure plate. The upper clamping plate is positioned above the lower clamping plate and inside the oil tank; the upper clamping plate has a ring structure and a pair of bolt holes are symmetrically arranged around the central hole of the upper clamping plate; the upper clamping plate is nested on the conductive tube and a gap is left between the upper clamping plate and the outer wall of the conductive tube. The locking bolt passes through the bolt hole of the upper clamping plate, and the bottom end of the locking bolt is connected to the countersunk thread hole on the lower clamping plate; the spring is nested on the locking bolt and located between the upper clamping plate and the lower clamping plate; a connecting nut is provided at the top of the locking bolt and connected to the locking bolt to press the upper clamping plate against the top of the spring; The tightening nut is positioned above the upper tightening plate, and the tightening nut engages with the threaded section on the conductive tube to press the lower tightening plate against the bottom surface of the inner wall of the oil tank.
2. The bushing head device for preventing gas backflow in an oil-immersed transformer according to claim 1, characterized in that: The inner wall of the center opening of the tightening lower pressure plate is provided with a first sealing groove, and the lower surface of the tightening lower pressure plate is provided with a second sealing groove at the junction with the lower surface of the inner wall of the oil tank. Both the first sealing groove and the second sealing groove are provided with sealing rubber.