Bar-shaped off-circuit tap-changer device

Abstract

The invention discloses a strip-shaped off-circuit tap-changer device which comprises a supporting structure, three phases of static contact assemblies are arranged on the supporting structure, and each phase of static contact assembly is provided with a moving contact assembly. A rack capable of sliding back and forth is arranged in the supporting structure; the moving contact assembly is installed on the rack and can move back and forth along with the rack. A transmission shaft is rotationally mounted on the supporting structure; a gear meshed with the rack is coaxially fixed on the transmission shaft; the gear shifting limiting and locking mechanism comprises a gear indicating board, a handle and a limiting piece. The gear indication board is fixedly arranged on the transformer and arranged outside the transmission shaft in a sleeving mode. A plurality of positioning holes are formed in the gear indication board; the handle is positioned above the gear indication board and is fixed on the transmission shaft; the limiting piece is in threaded connection with the handle, and after the limiting piece is aligned with the positioning hole, the limiting piece spirally moves downwards and is inserted into the positioning hole. The device is simple in structure, stable and reliable in performance, low in manufacturing cost, investment-saving and good in anti-corrosion and moisture-proof performance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of bar-shaped no-load tap changer, and particularly relates to a bar-shaped no-load tap changer device, which is mainly applied to a transformer. BACKGROUND

[0002] The core limitation of no-load tap changer is that its operation must be performed in the state of complete power-off of the transformer (i.e. no excitation). This characteristic determines that its application scenarios are mainly concentrated in the fields that do not have high requirements for power continuity, do not frequently adjust voltage, and can accept planned power-off. Therefore, no-load tap changers are widely used in general power transformers, distribution transformers, wind power box-type transformers, traction transformers and other equipment.

[0003] In terms of structure, the no-load tap changers on the market can be mainly divided into cage-shaped, drum-shaped, bar-shaped and disc-shaped types. Among them, cage-shaped, drum-shaped and bar-shaped switches are mainly applied to oil-immersed transformers, while disc-shaped switches are mainly used for dry-type transformers. In the oil-immersed application scenario, cage-shaped and drum-shaped switches are usually large in size and high in cost; in comparison, bar-shaped no-load tap changers have been widely used in the market due to their compact structure and low cost.

[0004] However, the application of bar-shaped no-load tap changers also faces certain challenges. For example, in extremely harsh environments such as offshore wind power, transformers and their components need to withstand severe mechanical shaking (such as ship movement or storm impact), long-term wind and rain erosion, and potential salt mist or even seawater immersion risks. This requires no-load tap changers not only to have inherent structural stability, but also to have excellent corrosion resistance (especially salt mist corrosion resistance) and moisture-proof sealing performance for exposed operating components. For such harsh working conditions, it is essential to develop a bar-shaped no-load tap changer with simple and reliable structure, low manufacturing cost, and environmental tolerance requirements to meet the needs of specific markets.

[0005] At present, the mainstream bar-shaped no-load tap changers on the market are generally applicable to transformers with relatively low working voltage levels and rated working currents (usually below 10kV and tens of amperes). With the expansion of application scenarios and the development of transformer technology, the market has higher requirements for bar-shaped no-load tap changers, especially for applications in medium voltage levels (12kV to 35kV) and rated working currents up to 200A and below. The design of existing bar-shaped switches often fails to meet the requirements of structural simplification, cost control and harsh environment adaptability while meeting higher electrical parameters.

[0006] Therefore, there is an urgent need for a new type of strip no-load tap changer, which has a working voltage range of 12-35 kV, a rated working current of not higher than 200 A, and simple and reliable structure, low manufacturing cost, and excellent anti-vibration, anti-corrosion and anti-moisture performance, to meet the growing market demand, especially in harsh environments such as offshore wind power. SUMMARY

[0007] To solve the above problems, the purpose of the present application is to provide a strip no-load tap changer device, which has simple structure, stable and reliable performance, low manufacturing cost, can save procurement cost for transformer manufacturing, reduce transformer box, save investment, improve its anti-corrosion and anti-moisture performance to ensure normal and reliable operation in harsh environment, and can meet the market demand of strip no-load tap changer for oil-immersed transformer with working voltage of 12-35 kV and working current of not higher than 200 A.

[0008] The purpose of the present application is achieved by the following technical solutions: A strip no-load tap changer device, comprising a support structure, three-phase static contact assemblies are arranged on the support structure, and one dynamic contact assembly is arranged for each static contact assembly; a long strip-shaped accommodation space is arranged inside the support structure, and a rack capable of sliding back and forth in the length direction of the accommodation space is arranged in the accommodation space; the dynamic contact assembly is mounted on the rack and can move back and forth with the rack; a transmission shaft is rotatably mounted on the support structure, and a gear meshing with the rack is fixed coaxially on the transmission shaft; a gear shifting and limiting locking mechanism is further included, the gear shifting and limiting locking mechanism comprises a gear position indicator, a handle and a limiting piece; the gear position indicator is fixedly arranged on the transformer and sleeved on the transmission shaft, and a plurality of gear position numbers for indicating the gear position are arranged on the upper surface of the gear position indicator; a plurality of positioning holes corresponding to the gear position numbers on the gear position indicator are arranged on the gear position indicator; the handle is located above the gear position indicator and is fixedly arranged on the transmission shaft; the limiting piece is threadedly connected in a pre-threaded hole of the handle and the lower end thereof points to the gear position indicator, and the limiting piece can be aligned with the positioning hole on the gear position indicator by rotating the handle, and the lower end of the limiting piece can be screwed downward and inserted into the positioning hole after the limiting piece is aligned with the positioning hole.

[0009] In one structure of the present application, the gear shifting and limiting locking mechanism further comprises a locking mechanism, the locking mechanism comprises a lock hole and a lock, the lock hole is arranged on the limiting piece and vertically penetrates the limiting piece; the lock is a padlock, when the lower end of the limiting piece is inserted into the positioning hole, the lock bar of the padlock passes through the lock hole and is reconnected in the lock body of the padlock; when the lower end of the limiting piece is inserted 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, and when the lower end of the limiting piece is separated from the positioning hole, the lock hole moves into the threaded hole of the handle.

[0010] The support structure comprises an insulating support strip, a metal support and a nylon support; the insulating support strip is arranged in parallel along the length direction of the support structure on the side of the rack, and three-phase static contact assemblies are arranged on the same side of the insulating support strip; the metal support is two in number and is fixed at the two ends of the insulating support strip; the transmission shaft is rotatably installed on one of the metal supports; the nylon support is a plurality of plate bodies which are vertically fixed on the insulating support strip and located between the two metal supports, and a rectangular hole which is sleeved on the rack is arranged in the center of each nylon support.

[0011] In one structure of the present application, the insulating support strip is two in number and is arranged in parallel on the front and back sides of the rack, the front and back 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, and the three-phase static contact assemblies are arranged on one of the insulating support strips, and three groups of neutral point contact assemblies corresponding to the three-phase static contact assemblies are arranged on the other insulating support strip, and one of the static contacts of each static contact assembly is bridged with the corresponding neutral point contact assembly through a moving contact assembly.

[0012] In another structure of the present application, the insulating support strip is one in number and is arranged in parallel on the front side or the back side of the rack, the two metal supports are fixed on the left and right ends of the insulating support strip respectively, the nylon support is vertically fixed on the insulating support strip, and the three-phase static contact assemblies are arranged on the insulating support strip, and the two adjacent static contacts of each static contact assembly are bridged through a moving contact assembly. This structure changes the contact mode of the moving contact and the static contact, one group of moving contacts contacts two groups of static contacts at a time, cancels the neutral point contact, and realizes the single-bridge cross connection voltage regulation mode, and can change the related structure to realize more voltage regulation modes and cover more use ranges.

[0013] The present application has the following advantages: (1) simple structure and low manufacturing cost: The long rack + gear linear motion mechanism (instead of the traditional complex cam or connecting rod mechanism) is adopted to realize the synchronous movement of the moving contact, and the structure is intuitive and simple. The support structure is optimized, and the combination of the insulating support strip, the metal end support and the nylon support in the middle is used. The nylon support (with a rectangular hole sleeving the rack) provides sliding support and insulation, which simplifies the manufacturing and assembly compared with the all-metal structure. Standardized components are used, and the three-phase static contact, the moving contact, the rack, the gear and the transmission shaft are relatively standardized, which is easy to produce and assemble. The overall design is compact, the component layout is reasonable, and the redundant structure is reduced.

[0014] (2) stable and reliable performance: Rack and pinion transmission: The meshing transmission mode is reliable and accurate in positioning, which can ensure the precise alignment of the moving contact with the static contact, good contact, and reduction of contact resistance and heat. In the gear shifting limiting and locking mechanism, the gear position indicator and the positioning hole are provided to provide clear gear position indication. The limiting member is inserted into the positioning hole through the screw to achieve mechanical limiting, which effectively prevents gear deviation caused by vibration or misoperation. The locking mechanism (lock hole + padlock) is provided, which can provide physical locking after the limiting member is inserted into the positioning hole, meets the safety operation specification of power equipment (such as preventing misoperation "five prevention" of preventing misoperation), and greatly improves the operation safety. The nylon support is provided to provide stable sliding support, good wear resistance, reduced rack movement resistance, and improved service life.

[0015] (3) Save space (reduce the transformer box): The overall structure is long strip-shaped, which fully utilizes the longitudinal space of the transformer oil tank. The static contact, the moving contact and the transmission mechanism are closely arranged along the rack direction to form a compact layout. The heavy full-metal frame is replaced by the insulating strip and the nylon member, so that the support structure is lightened. This structure design significantly reduces the overall volume of the switch device, thereby allowing the design of a smaller transformer tank, saving materials and installation space.

[0016] (4) Improve corrosion and moisture resistance, adapt to harsh environments: The key insulating components of the present application mainly use insulating support strips (such as epoxy plates, etc.) and nylon support members. These materials themselves have good oil resistance, corrosion resistance and moisture resistance. Compared with the full-metal frame structure, the metal exposure is reduced, and the area of the metal parts (mainly the metal support members at both ends and the transmission shaft) exposed to the oil is greatly reduced. The nylon material not only provides support and insulation, but also has excellent chemical corrosion resistance and low water absorption, which further improves the long-term stability of the switch in the transformer oil environment. The entire device is installed on the transformer tank cover or wall, and the internal space (including the rack, gear, etc.) is communicated with the transformer oil tank and is in the protection of the insulating oil. The external operating part (handle, indicator, limiting member) is designed to be simple and easy to seal.

[0017] (5) Save procurement costs and investment: The structure simplification and material optimization (such as the use of nylon members) directly reduce the manufacturing cost of the switch itself. The volume reduction (switch itself and transformer tank) saves the raw materials (metal, insulating material, transformer oil) and transportation cost. The improvement of reliability reduces the operation and maintenance cost and the risk of failure, which indirectly saves the investment.

[0018] (6) Meet the needs of specific markets (12-35kV, ≤200A): The application is specifically directed to the application scenario of working voltage 12~35kV and working current not higher than 200A in oil-immersed transformer. The structural strength, insulation level and contact current carrying capacity are optimized around this range, which can reliably meet the demand of this submarket.

[0019] In summary, the application successfully realizes the core goals of structure simplification, cost reduction, volume reduction, reliability enhancement, anti-corrosion and moisture-proof performance improvement, etc. by the innovative rack and pinion linear transmission structure, optimized support combination (insulating strip + metal end piece + nylon support piece), effective gear shifting limiting and locking mechanism (including mechanical limiting and padlock locking) and reasonable material selection (nylon and insulating plate), and provides a highly competitive no-field-tap switch solution for 12~35kV, ≤200A oil-immersed transformer. BRIEF DESCRIPTION OF DRAWINGS

[0020] The application will be further described in detail below with reference to the accompanying drawings.

[0021] Figure 1 Structure diagram of the strip-shaped no-field-tap switch device described in embodiment 1.

[0022] Figure 2 Top view of the strip-shaped no-field-tap switch device described in embodiment 1.

[0023] Figure 3 Rear view of the strip-shaped no-field-tap switch device described in embodiment 1.

[0024] Figure 4 Structure diagram of the support structure described in embodiment 1. Figure 3 Cross-sectional view in A-A direction.

[0025] Figure 5 Top view of the support structure described in embodiment 1.

[0026] Figure 6 Structure diagram of the moving contact assembly described in the application.

[0027] Figure 7 Structure diagram of the moving contact assembly described in embodiment 1. Figure 6 Cross-sectional view in B-B direction.

[0028] Figure 8 Top view of the stationary contact assembly described in the application.

[0029] Figure 9 Rear view of the stationary contact assembly described in the application.

[0030] Figure 10 Top view of the neutral point contact assembly described in embodiment 1.

[0031] Figure 11Structure diagram of the shift position limiting and locking mechanism.

[0032] Figure 12 Structure diagram of the strip-shaped off-circuit tap changer device.

[0033] As shown in the figure: 1-shift position limiting and locking mechanism, 1.1-handle, 1.2-limiting part, 1.3-gear position indicator, 1.4-mounting bolt, 1.5-lock hole, 1.6-transmission shaft, 1.7-mounting flange; 2-rack and pinion transmission mechanism, 2.1-gear, 2.2-rack; 3-supporting structure; 4-moving contact assembly; 5-static contact assembly; 6-neutral point contact assembly. DETAILED DESCRIPTION

[0034] The specific embodiments of the present application will be described below, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification. The described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative efforts fall within the scope of protection of the present application.

[0035] It should be understood that the structure, proportion, size, etc. shown in the drawings of the specification are only used to cooperate with the content disclosed in the specification for those skilled in the art to understand and read, and are not used to limit the conditions that the present application can be implemented, so they do not have technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects that the present application can produce and the purposes that the present application can achieve, should still fall within the scope of the technical content disclosed by the present application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and the like used in the specification are only for easy understanding and clear description, not to limit the scope of the present application that can be implemented, and the change or adjustment of the relative relationship without substantially changing the technical content is also considered as the scope of the present application that can be implemented.

[0036] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. Embodiment 1

[0037] As Figures 1-3 shown, the present embodiment provides a strip-shaped off-circuit tap changer device, which comprises a supporting structure 3 and a shift position limiting and locking mechanism 1.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] The nylon support 3.5 is a plurality of plate bodies vertically fixed on the two insulating support strips 3.3 and 3.4 and located between the two metal supports 3.1 and 3.2, the front and rear ends of the nylon support 3.5 are fixed between the two insulating support strips 3.3 and 3.4 by bolts, and a rectangular hole slidingly sleeved on the rack 2.2 is arranged at the center of each nylon support 3.5, the rectangular hole at the center of the nylon support 3.5 is used for supporting the rack 2.2, so that the rack 2.2 can smoothly complete linear motion, and the two ends of the nylon support 3.5 are used for supporting the insulating support strips 3.3 and 3.4, so as to ensure that the overall structure is more firm.

[0043] As Figure 6 With Figure 7 As shown in the figure, the moving contact assembly includes upper clamp piece contact 4.1, lower clamp piece contact 4.2 and moving contact shaft pin 4.3; the upper clamp piece contact 4.1 and the lower clamp piece contact 4.2 are respectively located on the upper and lower sides of the rack 2.2, and are both metal conductors; the number of the moving contact shaft pin 4.3 is two, each moving contact shaft pin 4.3 penetrates the upper clamp piece contact 4.1, the rack 2.2 and the lower clamp piece contact 4.2 in sequence, the upper part of each moving contact shaft pin 4.3 extends upward above the upper clamp piece contact 4.1, a limiting plate with a diameter larger than that of the moving contact shaft pin 4.3 is fixed at the top (upper end) of each moving contact shaft pin 4.3, the lower part of each moving contact shaft pin 4.3 extends downward below the lower clamp piece contact 4.2, and a limiting sleeve 4.4 with a diameter larger than that of the moving contact shaft pin 4.3 is sleeved at the lower part of each moving contact shaft pin 4.3, and a positioning pin 4.6 arranged below the limiting sleeve 4.4 is transversely installed at the bottom (lower end) of each moving contact shaft pin 4.3, and a spring 4.5 is further sleeved at the upper part and the lower part of each moving contact shaft pin 4.3 respectively, the spring 4.5 at the upper part of each moving contact shaft pin 4.3 abuts between the limiting plate and the upper clamp piece contact 4.1, and the spring 4.5 at the lower part of each moving contact shaft pin 4.3 abuts between the limiting sleeve 4.4 and the lower clamp piece contact 4.2; the end parts of the upper clamp piece contact 4.1 and the lower clamp piece contact 4.2 located on the same side extend outward beyond the rack and form a clamping part therebetween. The lower surface of the extension part of the upper clamp piece contact 4.1 and the upper surface of the extension part of the lower clamp piece contact 4.2 are both convex arc transition surfaces, which are more conducive to up-down gear shifting. The front and rear ends of the moving contact assembly of the embodiment extend to the front and rear sides of the rack 2.2 to form two clamping parts, one of which clamps the upper and lower sides of one of the stationary contacts 5.1 of the stationary contact assembly 6, and the other clamps the upper and lower sides of the neutral point contact 6.1. The clamping part is compressed by the spring 4.4 through the upper clamp piece contact 4.1 and the lower clamp piece contact 4.2, and the spring 4.4 supports the upper clamp piece contact 4.1 and the lower clamp piece contact 4.2, so that after gear shifting, the upper clamp piece contact 4.1 and the lower clamp piece contact 4.2 can be in close contact with the stationary contact 5.1 and the neutral point contact 6.1, avoiding poor contact leading to short circuit and other serious consequences.

[0044] AsFigure 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.

[0045] 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.

[0046] 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.

[0047] The handle 1.1 is located above the gear indicator 1.3 and is fixed on the transmission shaft 1.6, and the transmission shaft 1.6 can be axially rotated by rotating the handle 1.1; the lower part of the handle 1.1 is transversely arranged above the gear indicator 1.3 and is fixedly connected with the transmission shaft 1.6 through the mounting bolt 1.4, and the upper part of the handle 1.1 is first bent upward and then downward to form a C-shaped structure (the handle 1.1 is designed according to the normal palm size of adults to ensure the comfort of the user during operation, and the handle 1.1 is composed of two horizontal rods with different lengths arranged transversely above the gear indicator 1.3 and a vertical rod arranged vertically between the two horizontal rods, with the shorter horizontal rod at the lower part and the longer horizontal rod at the upper part). In order to ensure the traceability of the product, the product related information is printed on the top and side (top and side of the longer horizontal rod) of the handle 1.1 by laser, and the related product information on the handle 1.1 can quickly locate the product related production information, which can greatly improve the subsequent maintenance efficiency.

[0048] The limiting piece 1.2 is screw-connected in the preset threaded hole of the handle 1.1 (the lower part of the shorter horizontal rod), and the lower end (vertical) of the limiting piece 1.2 points to the gear indicator 1.3, and the limiting piece 1.2 can be aligned with the positioning hole on the gear indicator 1.3 by rotating the handle 1.1, and after the limiting piece 1.2 is aligned with the positioning hole, the lower end of the limiting piece 1.2 can be spirally moved downward and inserted into the positioning hole. The limiting piece 1.2 includes a twisting part, a screw part and a locking rod part which are coaxially fixed as a whole and all have a cylindrical shape; the twisting part is located on the side of the handle 1.1 away from the gear indicator 1.3, and the outer side of the twisting part is provided with anti-skid lines (knurls), the screw part is provided with external threads and is screw-connected in the preset threaded hole of the handle 1.1, and the locking rod part can be inserted into or separated from the positioning hole by moving up and down with the screw part, and the locking rod part is in sliding fit with the positioning hole, and the locking rod part can be easily slid into the positioning hole, but still maintains close connection.

[0049] The locking mechanism includes a lock hole 1.5 and a lock, and the lock hole 1.5 is arranged on the limiting piece 1.2 and vertically penetrates the limiting piece 1.2; the lock is a padlock, and when the lower end of the limiting piece 1.2 is inserted into the positioning hole, the lock bar of the padlock passes through the lock hole 1.5 and is reconnected in the lock body of the padlock; when the lower end of the limiting piece 1.2 is inserted 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 indicator 1.3, and when the lower end of the limiting piece 1.2 is separated from the positioning hole, the lock hole 1.5 moves into the threaded hole of the handle 1.1. After the locking rod part at the bottom of the limiting piece 1.2 is inserted into the positioning hole of the gear indicator 1.3, the lock bar of the padlock passes through the lock hole 1.5 and is reconnected in the lock body of the padlock, and then the padlock can be locked, which further ensures the self-locking property of the gear, and the key of the padlock is kept on the professional operator to avoid illegal operation by non-professional operators, and to ensure the normal operation of the equipment and personal safety.

[0050] In order to ensure that the shift limiting and locking mechanism can be normally used in humid, sunning and other harsh environments, the entire shift limiting and locking mechanism 1 is processed by using 316L material to avoid oxidation and rust in harsh environments for a long time, thereby reducing the service life.

[0051] The installation method for installing the strip-shaped non-excitation tap changer on the transformer is as follows: First, the gear indicator 1.3 is not fixed on the mounting flange 1.7, the transmission shaft 1.6 is inserted into the mounting flange inner hole 1.7 of the transformer from bottom to top, the metal support 3.1 and 3.2 at both ends of the support structure 3 in the strip-shaped non-excitation tap changer are fixed with the transformer fixing plate by using fixing bolts, and then the shift limiting and locking mechanism 1 is installed on the switch (the gear indicator 1.3 is sleeved on the outer side of the upper end of the transmission shaft 1.6 and is fixed on the mounting flange 1.7, and the handle 1.1 is fixed on the upper end of the transmission shaft 1.6 by using the mounting bolt 1.4), that is, the installation is completed.

[0052] When the strip-shaped non-excitation tap changer is shifted, the handle 1.1 on the shift limiting and locking mechanism 1 is operated by hand, and the upshift or downshift operation is performed according to the indication on the gear indicator 1.3. When shifting, the padlock in the lock hole 1.5 at the lower end of the limiting part 1.2 is removed, and then the limiting part 1.2 is screwed upward until the lock rod part at the bottom of the limiting part 1.2 completely exits the positioning hole of the gear indicator 1.3, and then the handle 1.1 is rotated for shifting operation. When the handle 1.1 is rotated to the desired gear position, the limiting part 1.2 is screwed downward and inserted into the positioning hole of the gear indicator 1.3 (the specific operation is as follows: the screwing part of the limiting part 1.2 is screwed from bottom to top, the screw rod part and the lock rod part are moved downward until the lock rod part at the bottom of the limiting part 1.2 completely exits the positioning hole of the gear indicator 1.3, the handle 1.1 is rotated, the gear rack transmission mechanism 2 is driven to move the rack 2.2 and the movable contact assembly 4 to the next gear position, the movable contact assembly 4 is in contact with the static contact 5.1 of the next gear position, the shifting operation is realized, and after rotating to the desired shifting position, the limiting part 1.2 is screwed downward to check whether the lock rod part can be smoothly inserted into the positioning hole of the gear indicator 1.3, whether the lock rod part is aligned with the positioning hole of the specified gear position, the gear position is adjusted by rotating the handle 1.1, the limiting part 1.2 is continuously rotated and moved downward until the lock rod part of the limiting part 1.2 can be completely and smoothly inserted into the positioning hole of the gear indicator 1.3, and if necessary, the padlock is hung, and the precise gear switching is completed), so as to achieve the effect of precise shifting and avoid serious consequences caused by improper shifting, and the padlock can avoid serious consequences caused by random operation of the switch by non-professional authorized personnel. The shift limiting and locking mechanism with simple structure can greatly improve the safety performance of the strip-shaped non-excitation tap changer.

[0053] The rotating handle 1.1 drives the gear 2.1 fixed on the transmission shaft, the linear motion of the rack 2.2 is driven by the torque of the gear 2.1, and the movable contact assembly 4 fixed on the rack 2.2 is driven, so that the movable contact assembly 4 contacts the static contact 5.1 of the expected gear shifting, and the gear shifting purpose is achieved. In addition, the spacer 2.3 is arranged below the rack 2.2 to support the end of the rack 2.2, so that the gear and rack transmission mechanism 2 composed of the gear 2.1 and the rack 2.2 can run smoothly without jamming. The gear and rack transmission mechanism 2 is not only accurate in transmission but also small in structure. According to the number of teeth on the rack 2.2, the limiting piece 1.2 and the positioning hole can ensure that the movable contact and the static contact do not slip, and avoid the problem of difficult upshift caused by the movable contact slipping out of the static contact at both ends due to misoperation. Example 2

[0054] The voltage regulating mode of example 1 is neutral point linear voltage regulation, which can be changed by changing the movable contact assembly 4, the neutral point contact assembly 6 and the support structure 3, etc. to form the single-bridge cross-border strip-shaped non-excitation tap changer structure shown in the embodiment. The single-bridge cross-border strip-shaped non-excitation tap changer structure shown in the embodiment is obtained by changing the contact mode of the movable contact assembly 4 and the static contact 5.1 on the basis of example 1, that is, one set of movable contact assembly 4 contacts two sets of static contact 5.1 at a time.

[0055] The difference between the present embodiment and example 1 is that: The support structure 3 includes an insulating support plate, a metal support and a nylon support; the number of the insulating support plate is one and it is arranged in parallel along the length direction of the support structure on the front side or the rear side of the rack; the number of the metal support is two and it is fixed at both ends of the insulating support plate, the two metal supports 3.1 and 3.2 are respectively fixed on the left and right ends of the insulating support plate, and the two metal supports 3.1 and 3.2 are also fixedly connected with the transformer; the transmission shaft 1.6 is rotatably installed on one of the metal supports 3.1; the nylon support 3.5 is a plurality of plate bodies vertically fixed on the insulating support plate and located between the two metal supports 3.1 and 3.2, and a rectangular hole slidably sleeved on the rack is arranged at the center of each nylon support 3.5.

[0056] The three-phase stationary contact assemblies 5 are arranged on the same side of the insulating support plate strip respectively, two adjacent stationary contacts 5.1 of each phase stationary contact assembly 5 are bridged by one movable contact assembly 4, that is, the movable contact assembly 4 has only one clamping part, in the embodiment, the stationary contact assembly 5 has six stationary contacts 5.1, one end of the movable contact assembly 4 extends to the stationary contact assembly 5 and contacts two stationary contacts 5.1 of the stationary contact assembly 5, during gear shifting, with the back and forth movement of the gear rack 2.2, one end of the movable contact assembly 4 alternately contacts two adjacent stationary contacts 6.1 of the stationary contact assembly 5 (the upper clamping piece contact 4.1 and the lower clamping piece contact 4.2 of the clamping part are clamped on the upper and lower sides of the two adjacent stationary contacts 6.1 on the left and right of the spring 4.4, and the two adjacent stationary contacts 6.1 are conducted), gear shifting is realized, and the switching of five gears can be realized.

[0057] The embodiment realizes the single-bridge cross-connection voltage regulation mode by canceling the neutral point contact, and in addition, more voltage regulation modes can be realized by changing the related structure, covering more use ranges, for example, the relative positions of the gear shifting gear rack mechanism 2 between the three groups of contact assemblies (including the movable contact assembly 4 and the stationary contact assembly 5) can be changed, various transformer internal structure use requirements are met, and the strip-shaped no-load tap changer described in the application can meet more transformer use requirements.

[0058] The other details of the application are well known to those skilled in the art.

[0059] It should be noted that the terms “include”, “contain” or any other variant are intended to cover non-exclusive inclusion, so that the process, method, article or device containing a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device.

[0060] The protection scope of the application is not limited to the technical solutions disclosed in the specific embodiments, and any modification, equivalent replacement, improvement, etc. made according to the technical essence of the application to the above embodiments falls within the protection scope of the application.

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 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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