A strip-shaped de-energized tap changer device

Abstract

The utility model discloses a strip no -excitation tap changer device, including support structure, is equipped with three -phase static contact component on the support structure, and each phase static contact component configures a moving contact component, is equipped with the rack that slides back and forth in the support structure, and the moving contact component is installed on the rack and can move back and forth with the rack, is rotatably installed with transmission shaft on the support structure, and the gear that is interlocked with the rack is fixedly installed on transmission shaft coaxially, still include gearshift limit locking mechanism, and gearshift limit locking mechanism includes gear position indicator, handle and spacing piece, and gear position indicator is fixedly arranged on the transformer and is set on transmission shaft outside, is equipped with a plurality of positioning holes on gear position indicator, and handle is located above gear position indicator and is fixed on transmission shaft, and spacing piece is screw -threaded connection on handle, and after spacing piece is aligned positioning hole, spiral moves down and inserts into positioning hole. The utility model has the advantages of simple structure, stable and reliable performance, low manufacturing cost, saving investment, good anticorrosive and moisture-proof performance.

Description

Technical Field

[0001] This utility model belongs to the technical field of bar-type non-excitation tap changers, specifically relating to a bar-type non-excitation tap changer device, which is mainly used in transformers. Background Technology

[0002] The core limitation of off-grid tap changers is that their operation must be performed when the transformer is completely de-energized (i.e., without excitation). This characteristic determines that their application scenarios are mainly concentrated in areas where the requirements for power supply continuity are not high, voltage adjustment needs are not frequent, and planned power outages can be tolerated. Therefore, off-grid tap changers are widely used in general power transformers, distribution transformers, wind power box-type transformers, traction transformers, and other equipment.

[0003] Structurally, off-grid tap changers on the market can be mainly divided into squirrel-cage, drum-shaped, strip-shaped, and disc-shaped types. Among them, squirrel-cage, drum-shaped, and strip-shaped switches are mainly used in oil-immersed transformers, while disc-shaped switches are mostly used in dry-type transformers. In oil-immersed applications, squirrel-cage and drum-shaped switches are usually larger and more expensive; in contrast, strip-shaped off-grid tap changers have gained widespread use in the market due to their compact structure and low cost.

[0004] However, the application of strip-type non-excited tap changers also faces specific challenges. For example, in extreme and harsh environments such as offshore wind power, transformers and their components must withstand severe mechanical shaking (such as ship movement or wave impact), long-term wind and rain erosion, and potential risks of salt spray or even seawater immersion. This requires non-excited tap changers to not only possess inherent structural robustness, but also that their exposed operating parts have excellent corrosion resistance (especially resistance to salt spray corrosion) and moisture-proof sealing performance. For such demanding operating conditions, developing a strip-type non-excited tap changer with a simple and reliable structure, low manufacturing cost, and environmental tolerance requirements is crucial to meeting specific market needs.

[0005] Currently, mainstream bar-type non-excited tap changers are generally suitable for transformers with relatively low operating voltage levels and rated operating currents (typically 10kV and below, with currents in the tens of amperes). With the expansion of application scenarios and the development of transformer technology, the market has placed higher demands on bar-type non-excited tap changers, especially for applications requiring medium voltage levels (12kV to 35kV) and rated operating currents increased to 200A and below. Existing bar switch designs, while meeting higher electrical parameters, often struggle to simultaneously achieve structural simplification, cost control, and adaptability to harsh environments.

[0006] Therefore, there is an urgent need for a new type of strip-shaped non-excitation tap changer with an operating voltage range of 12kV to 35kV, a rated operating current of no more than 200A, and features simple and reliable structure, low manufacturing cost, and excellent vibration resistance, corrosion resistance, and moisture resistance to meet the growing market demand, especially for applications in harsh environments such as offshore wind power. Utility Model Content

[0007] To address the aforementioned problems, the purpose of this utility model is to provide a strip-shaped non-excitation tap changer device. This device has a simple structure, stable and reliable performance, and low manufacturing cost. It can save procurement costs for transformer manufacturing, reduce transformer housing size, save investment, and improve its corrosion and moisture resistance to ensure normal and reliable operation in harsh environments. It can meet the market demand for strip-shaped non-excitation tap changers for oil-immersed transformers with operating voltages of 12-35 kV and operating currents not exceeding 200A.

[0008] The objective of this utility model is achieved through the following technical solution:

[0009] A strip-shaped non-excitation tap changer includes a support structure, on which a three-phase stationary contact assembly is mounted, each stationary contact assembly being configured with a moving contact assembly; an elongated accommodating space is provided inside the support structure, within which a rack capable of sliding back and forth along its length is provided; the moving contact assembly is mounted on the rack and can move back and forth with the rack; a drive shaft is rotatably mounted on the support structure, and a gear coaxially fixed on the drive shaft and meshing with the rack; it also includes a shift limit locking mechanism, the shift limit locking mechanism including a gear position indicator, a handle, and a limit... Positioning component; the gear position indicator is fixedly mounted on the transformer and sleeved on the outside of the drive shaft, and has several gear position numbers on the upper surface of the gear position indicator; the gear position indicator has several positioning holes that correspond one-to-one with the gear position numbers on the gear position indicator; the handle is located above the gear position indicator and fixed on the drive shaft; the limiting component is threadedly connected to a pre-set threaded hole on the handle and its lower end points towards the gear position indicator, and the limiting component can be aligned with the positioning holes on the gear position indicator as the handle is rotated, and after the limiting component is aligned with the positioning hole, its lower end can be spirally moved down and inserted into the positioning hole.

[0010] In one structure of this utility model, the shifting limit locking mechanism further includes a locking mechanism. The locking mechanism includes a lock hole and a lock. The lock hole is disposed on the limit member and perpendicularly passes through the limit member. The lock is a padlock. When the lower end of the limit member is inserted into the positioning hole, the lock beam of the padlock passes through the lock hole and is re-fastened to the lock body of the padlock. When the lower end of the limit member is inserted downward into the positioning hole, the lock hole is located between the lower surface of the handle and the upper surface of the gear position indicator. When the lower end of the limit member is disengaged upward from the positioning hole, the lock hole moves into the threaded hole of the handle.

[0011] The support structure includes insulating support strips, metal support members, and nylon support members; the insulating support strips are arranged parallel to the rack side along the length of the support structure, and the three-phase stationary contact assemblies are respectively arranged on the same side of the insulating support strips; there are two metal support members, which are respectively fixed at both ends of the insulating support strips; the drive shaft is rotatably mounted on one of the metal support members; the nylon support members are several plates that are vertically fixed on the insulating support strips and located between the two metal support members, and each nylon support member has a rectangular hole at its center that is slidably fitted onto the rack.

[0012] In one structure of this utility model, there are two insulating support strips arranged in parallel on the front and rear sides of the rack. The front and rear ends of each metal support are fixed on the two insulating support strips respectively. The nylon support is fixed between the two insulating support strips. The three-phase stationary contact assemblies are all arranged on one of the insulating support strips. Three sets of neutral point contact assemblies corresponding one-to-one with the three-phase stationary contact assemblies are provided on the other insulating support strip. One stationary contact of each phase stationary contact assembly is bridged with its corresponding neutral point contact assembly through a moving contact assembly.

[0013] In another structure of this utility model, the number of insulating support strips is one, and they are arranged parallel to each other on the front or rear side of the rack. Two metal supports are respectively fixed on the left and right ends of the insulating support strip, and a nylon support is vertically fixed on the insulating support strip. All three-phase stationary contact assemblies are arranged on the insulating support strip, and two adjacent stationary contacts of each phase stationary contact assembly are bridged by a moving contact assembly. This structure, by changing the contact method between the moving and stationary contacts, allows one set of moving contacts to contact two sets of stationary contacts at a time. Eliminating the neutral point contact enables a single-bridge bridging voltage regulation method. More voltage regulation methods can be achieved by changing the related structure, covering a wider range of applications.

[0014] The beneficial effects of this utility model are as follows:

[0015] (1) Simple structure and low manufacturing cost:

[0016] A linear motion mechanism using a long rack and pinion (replacing the traditional complex cam or linkage mechanism) achieves synchronous movement of the moving contact, resulting in a straightforward and simple structure. The support structure has been optimized, employing a combination of insulated support strips, metal end supports, and a central nylon support. The nylon support (with a rectangular hole to accommodate the rack) provides both sliding support and insulation, simplifying manufacturing and assembly compared to an all-metal structure. Standardized components are used; the three-phase stationary contact, moving contact, rack, gear, and drive shaft are relatively standardized, facilitating production and assembly. The overall design is compact, with a rational component layout, reducing redundant structures.

[0017] (2) Stable and reliable performance:

[0018] Rack and pinion transmission: This meshing transmission method is reliable and accurately positioned, ensuring precise alignment of the moving contact with the stationary contact, good contact, and reduced contact resistance and heat generation. In the shift limit locking mechanism, the gear position indicator and positioning hole provide clear gear indication. The limit element achieves mechanical limiting by spirally inserting into the positioning hole, effectively preventing gear shifting due to vibration or misoperation. The locking mechanism (lock hole + padlock) allows the padlock to pass through the lock hole after the limit element is inserted, providing physical locking and meeting the safety operation specifications for electrical equipment (such as preventing accidental opening and closing of switches in the "five preventions" of misoperation), greatly improving operational safety. The nylon support provides stable sliding support, has good wear resistance, reduces rack movement resistance, and extends service life.

[0019] (3) Save space (reduce transformer enclosure size):

[0020] The overall structure is elongated, making full use of the longitudinal space of the transformer tank. The stationary contacts, moving contacts, and transmission mechanism are closely arranged along the rack direction, forming a compact layout. Insulating strips and nylon components replace the bulky all-metal frame, resulting in a lightweight support structure. This structural design significantly reduces the overall size of the switchgear, allowing for the design of a smaller transformer enclosure, saving materials and installation space.

[0021] (4) Improve corrosion and moisture resistance to adapt to harsh environments:

[0022] The key insulating components of this invention mainly employ insulating support strips (such as epoxy boards) and nylon support members. These materials themselves possess excellent oil resistance, corrosion resistance, and moisture resistance. Compared to an all-metal frame structure, this design reduces metal exposure, significantly decreasing the area of ​​metal components (mainly the metal support members at both ends and the drive shaft) exposed to oil. The nylon material not only provides support and insulation, but its excellent chemical corrosion resistance and low water absorption further enhance the long-term stability of the switch in the transformer oil environment. The entire device is installed on the transformer tank cover or wall, with its internal space (including racks, gears, etc.) communicating with the transformer oil tank and protected by insulating oil. The external operating parts (handles, indicators, limiters) are simply designed and easy to seal.

[0023] (5) Savings in procurement costs and investment: Simplified structure and optimized materials (such as the use of nylon parts) directly reduce the manufacturing cost of the switch itself. Reduced size (of the switch itself and the transformer housing) saves on raw materials (metals, insulating materials, transformer oil) and transportation costs. Improved reliability reduces operation and maintenance costs and failure risks, indirectly saving investment.

[0024] (6) Meets specific market demands (12-35kV, ≤200A):

[0025] This invention specifically targets the application scenarios of oil-immersed transformers with operating voltages of 12~35kV and operating currents not exceeding 200A. Its structural strength, insulation level, and contact current carrying capacity are all optimized around this range, reliably meeting the needs of this niche market.

[0026] In summary, this utility model, through its innovative rack-and-pinion linear transmission structure, optimized support combination (insulating strips + metal end pieces + nylon support pieces), effective shifting limit locking mechanism (including mechanical limit and padlock locking), and reasonable material selection (nylon, insulating board), successfully achieves core objectives such as structural simplification, cost reduction, size reduction, enhanced reliability, and improved corrosion and moisture resistance. It provides a highly competitive non-excitation tap changer solution for 12~35kV, ≤200A oil-immersed transformers. Attached Figure Description

[0027] The present invention will now be described in further detail with reference to the accompanying drawings.

[0028] Figure 1 This is a schematic diagram of the structure of the bar-shaped non-excitation tap changer device described in Example 1.

[0029] Figure 2 This is a top view of the bar-shaped non-excitation tap changer device described in Example 1.

[0030] Figure 3 This is a rear view of the bar-shaped non-excitation tap changer device described in Example 1.

[0031] Figure 4 for Figure 3 A cross-sectional view along the AA direction.

[0032] Figure 5 This is a top view of the support structure described in Example 1.

[0033] Figure 6 This is a schematic diagram of the moving contact assembly described in this utility model.

[0034] Figure 7 for Figure 6 A cross-sectional view along the BB direction.

[0035] Figure 8 This is a top view of the stationary contact assembly described in this utility model.

[0036] Figure 9 This is a rear view of the stationary contact assembly described in this utility model.

[0037] Figure 10 This is a top view of the neutral point contact assembly described in Example 1.

[0038] Figure 11This is a schematic diagram of the shifting limit locking mechanism described in this utility model.

[0039] Figure 12 This is a schematic diagram of the structure of the bar-shaped non-excitation tap changer device described in Example 2.

[0040] The figure shows: 1-shift limit locking mechanism, 1.1-handle, 1.2-limiting component, 1.3-gear position indicator, 1.4-mounting bolt, 1.5-locking hole, 1.6-drive shaft, 1.7-mounting flange; 2-gear and rack transmission mechanism, 2.1-gear, 2.2-rack; 3-support structure; 4-moving contact assembly; 5-stationary contact assembly; 6-neutral point contact assembly. Detailed Implementation

[0041] The following specific embodiments illustrate the implementation of this invention. Those skilled in the art can easily understand other advantages and effects of this invention from the content disclosed in this specification. The described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments in this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0042] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of this invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of this invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0043] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" 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. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Example 1

[0044] like Figure 1-3 As shown, this embodiment provides a strip-shaped non-excitation tap changer device, including a support structure 3 and a shift limit locking mechanism 1.

[0045] A three-phase stationary contact assembly 5 is provided on the support structure 3, and each phase stationary contact assembly 5 is equipped with a moving contact assembly 4; an elongated accommodating space is provided inside the support structure 3, and a rack 2.2 that can slide back and forth along its length is provided in the accommodating space; the moving contact assembly 4 is mounted on the rack 2.2 and can move back and forth with the rack 2.2; a drive shaft 1.6 is rotatably mounted on the support structure 3, and a gear 2.1 that meshes with the rack 2.2 is coaxially fixed on the drive shaft 1.6. Figure 4 As shown, rack 2.2 and gear 2.1 constitute a rack and pinion transmission mechanism 2.

[0046] like Figure 5 As shown, the support structure 3 includes insulating support strips 3.3 and 3.4, metal support members 3.1 and 3.2, and nylon support member 3.5.

[0047] Two insulating support strips are arranged parallel to each other along the length of the support structure 1 on the front and rear sides of the rack 2.2. Three-phase stationary contact assemblies 5 are respectively mounted on one of the insulating support strips 3.3, and three sets of neutral point contact assemblies 6, each corresponding to one of the three-phase stationary contact assemblies, are mounted on the other insulating support strip 3.4. Therefore, the number of neutral point contact assemblies is also three. Figure 10 As shown, the neutral point contact assembly 6 adopts a "T" shaped structure, which can effectively and reliably contact the moving contact. The neutral point contact assembly 6 includes a neutral point contact 6.1 and two M8 bolts 6.3. The neutral point contact 6.1 is fixed to the insulating support strip 3.4 by the M8 bolts 6.3. The head of the M8 bolt 6.3 is provided with a shield 6.2, which not only ensures its firmness and stability, but also ensures the insulation performance of the switch.

[0048] Two metal supports are fixed to the left and right ends of the insulating support strips, respectively. The front and rear ends of each metal support are fixed to the two insulating support strips. The two metal supports are secured to the transformer using six sets of M8 bolts. The drive shaft 1.6 is rotatably mounted on one of the metal supports 3.1, ensuring the meshing of gear 2.1 and rack 2.2 on the drive shaft 1.6. Simultaneously, metal supports 3.1 and 3.2 are also secured to the insulating support strips 3.3 and 3.4 with metal bolts, ensuring switch stability. To guarantee the insulation performance of the strip-type de-energized tap changer, all metal bolts are equipped with metal shields 3.6.

[0049] The nylon support 3.5 consists of several plates vertically fixed to two insulating support strips 3.3 and 3.4 and located between two metal supports 3.1 and 3.2. The front and rear ends of the nylon support 3.5 are respectively fixed between the two insulating support strips 3.3 and 3.4 by bolts. Each nylon support 3.5 has a rectangular hole at its center that slides onto the rack 2.2. The rectangular hole at the center of the nylon support 3.5 is used to support the rack 2.2, so that the rack 2.2 can smoothly complete linear movement. At the same time, the two ends of the nylon support 3.5 are used to support the insulating support strips 3.3 and 3.4, ensuring that the overall structure is more robust.

[0050] like Figure 6 and Figure 7 As shown, the moving contact assembly includes an upper clamping contact 4.1, a lower clamping contact 4.2, and a moving contact pin 4.3. The upper clamping contact 4.1 and the lower clamping contact 4.2 are located on the upper and lower sides of the rack 2.2, respectively, and are both metal conductors. There are two moving contact pins 4.3, each of which sequentially moves through the upper clamping contact 4.1, the rack 2.2, and the lower clamping contact 4.2. The upper part of each moving contact pin 4.3 extends upward above the upper clamping contact 4.1, and a limiting plate with a diameter larger than its own diameter is fixed at the top (upper tip) of each moving contact pin 4.3. The lower part of each moving contact pin 4.3 extends downward to the lower clamping contact. Below 4.2, a limiting sleeve 4.4 with a diameter larger than the moving contact pin 4.3 is fitted onto the lower part of each moving contact pin 4.3. Simultaneously, a positioning pin 4.6 is horizontally installed below the limiting sleeve 4.4 at its bottom (lower end). Springs 4.5 are also fitted onto the upper and lower parts of each moving contact pin 4.3. The upper spring 4.5 abuts against the limiting plate and the upper clamping contact 4.1, while the lower spring 4.5 abuts against the limiting sleeve 4.4 and the lower clamping contact 4.2. The ends of the upper clamping contact 4.1 and the lower clamping contact 4.2, located on the same side, extend outwards beyond the rack and form a clamping portion between them. The lower surface of the extension of the upper clamping contact 4.1 and the upper surface of the extension of the lower clamping contact 4.2 are both convex arc transition surfaces, which facilitates shifting gears. In this embodiment, the front and rear ends of the moving contact assembly extend to the front and rear sides of the rack 2.2, forming two clamping portions. One clamping portion clamps the upper and lower sides of one of the stationary contacts 5.1 in the stationary contact assembly 6, and the other clamps the upper and lower sides of the neutral point contact 6.1. The clamping portions, through the compression of the spring 4.4 by the upper clamping contact 4.1 and the lower clamping contact 4.2, and the support of the upper clamping contact 4.1 and the lower clamping contact 4.2 by the spring 4.4, ensure that after shifting to the correct position, the upper clamping contact 4.1 and the lower clamping contact 4.2 can firmly contact the stationary contact 5.1 and the neutral point contact 6.1, avoiding serious consequences such as short circuits caused by poor contact.

[0051] like Figure 8 and Figure 9 As shown, the stationary contact assembly 5 includes five stationary contacts 5.1, enabling five different position changes. Each stationary contact 5.1 is fixed to the support structure 1 (insulating support strip 3.3) via a stationary contact pin 5.2 and a collar 5.3 threaded onto the pin 5.2. One end of each stationary contact 5.1 contacts one end of the moving contact assembly 4 (upper clamp contact 4.1 and lower clamp contact 4.2), while the other end is fixed with a soft copper stranded wire 5.4. The moving contact assembly 4 (the clamping part formed by the upper clamp contact 4.1 and lower clamp contact 4.2) contacts the stationary contacts 5.1 at different positions. Then, the corresponding transformer leads are connected to the soft copper stranded wire 5.4, allowing the transformer to be energized with different numbers of turns. The stationary contact 5.1 is designed with a cylindrical, rounded corner structure to meet the 200A current requirement. One of the stationary contacts 5.1 of each phase stationary contact assembly 5 is bridged with its corresponding neutral point contact assembly 6 (neutral point contact 6.1) through a moving contact assembly 4. That is, both ends of the moving contact assembly 4 extend to the stationary contact assembly 5 and the neutral point contact assembly 6, respectively. During gear shifting, as the rack 2.2 moves back and forth, one end of the moving contact assembly 4 alternately contacts each of the stationary contacts 5.1 of the corresponding stationary contact assembly 5, while the other end of the moving contact assembly 4 always remains in contact with the neutral point contact 6.1 of the corresponding neutral point contact assembly 6.

[0052] like Figure 11 As shown, the shift limit locking mechanism 1 includes a gear position indicator 1.3, a handle 1.1, a limit member 1.2, and a locking mechanism.

[0053] The gear position indicator 1.3 is fixedly mounted on the transformer via a mounting flange 1.7. Simultaneously, the gear position indicator 1.3 is fitted over the drive shaft 1.6 through a pre-drilled hole in its center, allowing the drive shaft 1.6 to rotate freely within the center of the gear position indicator 1.3. The mounting flange 1.7 is fixed to the transformer, and the gear position indicator 1.3 is secured to the top of the mounting flange 1.7 with two bolts. The upper end of the drive shaft 1.6 rotates upwards, fitting into the inner hole of the mounting flange 1.7 and then passing through the gear position indicator 1.3, extending above it. A double-seal ring system is used between the drive shaft 1.6 and the mounting flange 1.7 to ensure a tight seal between the switch and the transformer. The upper surface of the gear position indicator 1.3 is provided with a number of gear position numbers for indicating the gear position. In this embodiment, the gear position indicator 1.3 shows the gear position numbers corresponding to gears 1-5 respectively (the gear position numbers corresponding to the 5 gear positions). The gear position indicator 1.3 is provided with a number of positioning holes. The positioning holes are through holes that correspond one-to-one with the gear position numbers on the gear position indicator 1.3. Each positioning hole is located inside the corresponding gear position number.

[0054] The handle 1.1 is located above the gear position indicator 1.3 and fixed to the drive shaft 1.6. Rotating the handle 1.1 allows the drive shaft 1.6 to rotate axially. The lower part of the handle 1.1 is horizontally positioned above the gear position indicator 1.3 and is fixedly connected to the drive shaft 1.6 by mounting bolts 1.4. The upper part of the handle 1.1 is first bent upwards and then downwards to form a C-shaped structure (the handle 1.1 is designed to bend according to the normal size of an adult's palm to ensure user comfort. The handle 1.1 consists of two horizontal bars, one long and one short, positioned horizontally above the gear position indicator 1.3, and a vertical bar integrally positioned between the two horizontal bars, with the shorter bar at the bottom and the longer bar at the bottom). To ensure product traceability, product-related information is laser-printed on the top and sides of the handle 1.1 (the top and sides of the long bar). The relevant product information on the handle 1.1 allows for quick location of relevant production information, greatly improving the efficiency of subsequent maintenance and repair.

[0055] The limiting member 1.2 is threadedly connected to a pre-set threaded hole on the handle 1.1 (the lower short crossbar). The lower end (vertical) of the limiting member 1.2 points towards the gear position indicator 1.3. The limiting member 1.2 can align with the positioning hole on the gear position indicator 1.3 as the handle 1.1 rotates. After the limiting member 1.2 is aligned with the positioning hole, its lower end can spiral down and insert into the positioning hole. The limiting member 1.2 includes a rotating part, a screw part, and a locking part, which are coaxially fixed together and are all cylindrical. The rotating part is located on the side of the handle 1.1 facing away from the gear position indicator 1.3. The outer surface of the rotating part is provided with anti-slip texture (knurling). The screw part is provided with external threads and threadedly connected to the pre-set threaded hole on the handle 1.1. The locking part can be inserted into or disengaged from the positioning hole as the screw part moves up and down. The locking part slides into the positioning hole, and the locking part can easily slide into the positioning hole, but still maintains a tight connection.

[0056] The locking mechanism includes a lock hole 1.5 and a lock. The lock hole 1.5 is located on and perpendicularly passes through the limiting member 1.2. The lock is a padlock. When the lower end of the limiting member 1.2 is inserted into the positioning hole, the lock beam of the padlock passes through the lock hole 1.5 and is re-fastened into the lock body of the padlock. When the lower end of the limiting member 1.2 is inserted downward into the positioning hole, the lock hole 1.5 is located between the lower surface of the handle 1.1 and the upper surface of the gear position indicator 1.3. When the lower end of the limiting member 1.2 is disengaged upward from the positioning hole, the lock hole 1.5 moves into the threaded hole of the handle 1.1. After the locking rod at the bottom of the limiting member 1.2 is engaged in the positioning hole of the gear position indicator 1.3, the lock beam of the padlock passes through the lock hole 1.5 and is re-fastened into the lock body of the padlock, thus locking the device. This further ensures the self-locking property of the gear position. The padlock key is kept by a professional operator to prevent unauthorized operation by non-professional personnel, ensuring the normal operation of the equipment and personal safety.

[0057] To ensure that the shift limit locking mechanism can function properly in harsh environments such as humidity and direct sunlight, the entire shift limit locking mechanism 1 is made of 316L material to prevent oxidation and rust from occurring in harsh environments over a long period of time, thus reducing its service life.

[0058] The installation method for mounting a bar-type non-energized tap changer onto a transformer is as follows:

[0059] First, the gear position indicator 1.3 is not fixed to the mounting flange 1.7 yet. First, insert the drive shaft 1.6 into the inner hole 1.7 of the transformer mounting flange from bottom to top. Then, use fixing bolts to fix the metal support parts 3.1 and 3.2 at both ends of the support structure 3 in the bar-shaped non-excitation tap changer to the transformer mounting plate. Next, install the gear limit locking mechanism 1 on the switch (sleeve the gear position indicator 1.3 on the outer side of the upper end of the drive shaft 1.6 and fix it to the mounting flange 1.7, and fix the handle 1.1 to the upper end of the drive shaft 1.6 with the mounting bolt 1.4). The installation is then complete.

[0060] When shifting gears using the strip-type de-energized tap changer, manually operate the handle 1.1 on the shift limit locking mechanism 1, and perform upshifting or downshifting operations according to the instructions on the gear position indicator 1.3. Before shifting, first remove the padlock from the locking hole 1.5 at the lower end of the limit member 1.2, then rotate the limit member 1.2 upwards until the locking rod at the bottom of the limit member 1.2 is completely disengaged from the positioning hole of the gear position indicator 1.3. Only then can the handle 1.1 be rotated manually for shifting. When rotating handle 1.1 to the desired gear, screw the limiting part 1.2 downwards and insert it into the positioning hole of the gear indicator 1.3 (specifically, screw the rotating part of the limiting part 1.2 from bottom to top, causing the screw and locking rod to move downwards until the locking rod at the bottom of the limiting part 1.2 is completely exposed from the positioning hole of the gear indicator 1.3; then rotate handle 1.1, which drives the gear and rack transmission mechanism 2 via the transmission shaft 1.6, causing the rack 2.2 to move and move the moving contact assembly 4 to the next gear, where it contacts the stationary contact 5.1 of the next gear, thus completing the gear shifting operation; rotate to the desired gear position). After placement, screw the limiting member 1.2 downwards to check if the locking rod can be smoothly inserted into the positioning hole of the gear indicator 1.3. Confirm that the locking rod is aligned with the positioning hole of the designated gear. Adjust the gear position by rotating the handle 1.1. Continue to rotate and lower the limiting member 1.2 until the locking rod of the limiting member 1.2 can be fully and smoothly inserted into the positioning hole of the gear indicator 1.3. If necessary, engage the padlock to complete a precise gear shift. This achieves accurate gear shifting and avoids serious consequences caused by improper gear shifting. Adding the padlock can prevent unauthorized personnel from operating the switch and causing serious consequences. The simple gear shifting limit locking mechanism can greatly improve the safety performance of the bar-type non-excitation tap changer.

[0061] Rotating the handle 1.1 drives the gear 2.1 fixed on the drive shaft. The torque of the gear 2.1 drives the rack 2.2 to move linearly, which in turn drives the moving contact assembly 4 fixed on the rack 2.2. This causes the moving contact assembly 4 to contact the stationary contact 5.1, which is intended for shifting gears, thus achieving the purpose of shifting gears. Additionally, a pad 2.3 is placed below the rack 2.2 to provide support to the end of the rack 2.2, ensuring smooth and unobstructed operation of the gear and rack transmission mechanism 2 composed of the gear 2.1 and rack 2.2. The gear and rack transmission mechanism 2 is not only precise in transmission but also compact in structure. The limitation on the number of teeth on the rack 2.2, along with the fit of the limiting component 1.2 and the positioning hole, ensures that the moving contact and stationary contact do not slip, preventing the moving contact from sliding out of the stationary contacts at both ends due to misoperation, thus avoiding the problem of difficulty in shifting gears. Example 2

[0062] The voltage regulation method in Example 1 is neutral point linear voltage regulation. This regulation method can be altered by changing the moving contact assembly 4, the neutral point contact assembly 6, and the support structure 3, thus forming the single-bridge cross-sectional strip-shaped no-excitation tap changer structure shown in this example. The single-bridge cross-sectional strip-shaped no-excitation tap changer structure shown in this example is obtained by changing the contact method between the moving contact assembly 4 and the stationary contact 5.1, so that one set of moving contact assemblies 4 contacts two sets of stationary contacts 5.1 simultaneously.

[0063] The difference between this embodiment and Embodiment 1 is that:

[0064] The support structure 3 includes an insulating support strip, metal supports, and nylon supports. There is one insulating support strip, which is parallel to the length of the support structure and positioned on the front or rear side of the rack. There are two metal supports, each fixed to one end of the insulating support strip. The two metal supports 3.1 and 3.2 are fixed to the left and right ends of the insulating support strip, respectively, and are also fixedly connected to the transformer. The drive shaft 1.6 is rotatably mounted on one of the metal supports 3.1. The nylon supports 3.5 are several plates vertically fixed to the insulating support strip and located between the two metal supports 3.1 and 3.2. Each nylon support 3.5 has a rectangular hole at its center that slides onto the rack.

[0065] The three-phase stationary contact assemblies 5 are respectively arranged on the same side of the insulating support strip. The two adjacent stationary contacts 5.1 of each phase stationary contact assembly 5 are bridged by a moving contact assembly 4. That is, the moving contact assembly 4 has only one clamping part. In this embodiment, the stationary contact assembly 5 has 6 stationary contacts 5.1. One end of the moving contact assembly 4 extends to contact two of the stationary contacts 5.1 of the stationary contact assembly 5. When shifting gears, as the rack 2.2 moves back and forth, one end of the moving contact assembly 4 alternately contacts two of the adjacent stationary contacts 6.1 of the stationary contact assembly 5 (the upper clamping contact 4.1 and the lower clamping contact 4.2 of the clamping part are clamped on the upper and lower sides of the two adjacent stationary contacts 6.1 by the spring 4.4, connecting the two adjacent stationary contacts 6.1), thus realizing gear shifting and enabling the switching of five gears.

[0066] This embodiment achieves single-bridge bridging voltage regulation by eliminating the neutral point contact. In addition, the related structure can be changed to achieve more voltage regulation methods and cover a wider range of applications. For example, the relative position of the shift gear rack mechanism 2 among the three sets of contact assemblies (including the moving contact assembly 4 and the stationary contact assembly 5) can be changed to meet the usage requirements of various transformer internal structures, so that the strip-shaped non-excitation tap changer described in this utility model can meet the usage requirements of more transformers.

[0067] Other aspects of this utility model that are not detailed herein are all conventional techniques known to those skilled in the art.

[0068] It should be noted that the terms “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0069] The scope of protection of this utility model is not limited to the technical solutions disclosed in the specific embodiments. Any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of this utility model shall fall within the scope of protection of this utility model.

Claims

1. A strip-shaped non-excitation tap changer device, comprising a support structure, on which a three-phase stationary contact assembly is provided, each stationary contact assembly being configured with a moving contact assembly; an elongated receiving space is provided inside the support structure, and a rack capable of sliding back and forth along its length is provided within the receiving space; the moving contact assembly is mounted on the rack and can move back and forth with the rack; a drive shaft is rotatably mounted on the support structure, and a gear coaxially fixed on the drive shaft and meshing with the rack; characterized in that: It also includes a shift limit locking mechanism, which includes a gear position indicator, a handle, and a limit component; The gear position indicator is fixedly mounted on the transformer and sleeved on the outside of the drive shaft. The upper surface of the gear position indicator has several gear position numbers for indicating the gear position. The gear position indicator has several positioning holes that correspond one-to-one with the gear position numbers on the gear position indicator. The handle is located above the gear position indicator and is fixed on the drive shaft; The limiting member is threaded into a pre-set threaded hole on the handle and its lower end points to the gear position indicator. The limiting member can be aligned with the positioning hole on the gear position indicator as the handle is rotated. After the limiting member is aligned with the positioning hole, its lower end can be spiraled down and inserted into the positioning hole.

2. The strip-shaped non-excitation tap changer device according to claim 1, characterized in that: The lower part of the handle is horizontally positioned above the gear indicator and is fixedly connected to the drive shaft by bolts. The upper part of the handle is first bent upwards and then bent downwards to form a C-shaped structure. The limiting part is threadedly connected to the lower part of the handle.

3. The strip-shaped non-excitation tap changer according to claim 1, characterized in that: The limiting component includes a screw part, a screw part, and a locking rod part that are coaxially fixed together in sequence; the screw part is located on the side of the handle facing away from the gear position indicator, the screw part is threadedly connected to the handle, and the locking rod part can be inserted into or disengaged from the positioning hole as the screw part moves up and down.

4. The strip-shaped non-excitation tap changer according to claim 1, characterized in that: The shift limit locking mechanism also includes a locking mechanism, which includes a lock hole and a lock. The lock hole is located on the limit member and passes vertically through the limit member. The lock is a padlock. When the lower end of the limit member is inserted into the positioning hole, the lock beam of the padlock passes through the lock hole and is re-fastened into the lock body of the padlock. When the lower end of the limit member is inserted downward into the positioning hole, the lock hole is located between the lower surface of the handle and the upper surface of the gear position indicator. When the lower end of the limit member is disengaged upward from the positioning hole, the lock hole moves into the threaded hole of the handle.

5. The strip-shaped non-excitation tap changer according to claim 1, characterized in that: The support structure includes insulating support strips, metal support members, and nylon support members; the insulating support strips are arranged parallel to the rack side along the length of the support structure, and the three-phase stationary contact assemblies are respectively arranged on the same side of the insulating support strips; there are two metal support members, which are respectively fixed at both ends of the insulating support strips; the drive shaft is rotatably mounted on one of the metal support members; the nylon support members are several plates that are vertically fixed on the insulating support strips and located between the two metal support members, and each nylon support member has a rectangular hole at its center that is slidably fitted onto the rack.

6. The strip-shaped non-excitation tap changer according to claim 5, characterized in that: The number of insulating support strips is two, which are arranged in parallel on the front and rear sides of the rack. The front and rear ends of each metal support are fixed on the two insulating support strips respectively. The nylon support is fixed between the two insulating support strips. The three-phase stationary contact assemblies are all set on one of the insulating support strips. On the other insulating support strip, there are three sets of neutral point contact assemblies that correspond one-to-one with the three-phase stationary contact assemblies. One stationary contact of each phase stationary contact assembly is bridged with its corresponding neutral point contact assembly through a moving contact assembly.

7. The strip-shaped non-excitation tap changer according to claim 5, characterized in that: The number of insulating support strips is one and they are arranged in parallel on the front or rear side of the rack. Two metal supports are fixed on the left and right ends of the insulating support strip respectively. Nylon supports are vertically fixed on the insulating support strip. All three-phase stationary contact assemblies are arranged on the insulating support strip. Two adjacent stationary contacts of each phase stationary contact assembly are bridged by a moving contact assembly.

8. The strip-shaped non-excitation tap changer according to claim 1, characterized in that: The moving contact assembly includes an upper clamping contact, a lower clamping contact, and a moving contact pin. The upper and lower clamping contacts are located on the upper and lower sides of the rack, respectively. There are two moving contact pins, each of which sequentially penetrates the upper clamping contact, the rack, and the lower clamping contact. The upper part extends upward above the upper clamping contact and a limiting plate with a diameter larger than the pin is fixed at its top. The lower part extends downward below the lower clamping contact and a limiting sleeve with a diameter larger than the pin is fitted on it. At the same time, a positioning pin is installed horizontally at the bottom of the pin and located below the limiting sleeve. Springs are also fitted on the upper and lower parts of each moving contact pin. The upper spring abuts between the limiting plate and the upper clamping contact, and the lower spring abuts between the limiting sleeve and the lower clamping contact. The ends of the upper and lower clamping contacts on the same side extend outward outside the rack and form a clamping part between them.

9. The strip-shaped non-excitation tap changer according to claim 8, characterized in that: The lower surface of the upper clip contact extension and the upper surface of the lower clip contact extension are both convex arc transition surfaces.

10. The strip-shaped non-excitation tap changer according to claim 1, characterized in that: The stationary contact assembly includes several stationary contacts. Each stationary contact is fixed to the support structure by a stationary contact shaft pin and a collar threaded onto the stationary contact shaft pin. One end of the stationary contact is in contact with one end of the moving contact assembly, and the other end is fixed with a soft copper stranded wire.

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