Compact sheet-type contact sheet structure and off-circuit tap-changer comprising same

Abstract

The invention belongs to the technical field of off-circuit tap switches, and particularly relates to a compact type wafer structure and an off-circuit tap switch comprising the compact type wafer structure. Comprising a static contact, a supporting assembly and a moving contact assembly. The plurality of static contacts are arranged in pairs along the vertical direction; the supporting assembly comprises a guide rod and a side rod; the moving contact assembly comprises a supporting piece, a moving contact group and a spring group; the invention is mainly used for providing a compact type contact piece structure which is simple in structure, good in stability and convenient to use, and providing an off-circuit tap-changer which is smaller in occupied space, more in connecting contacts and higher in bearing capacity on the basis of the compact type contact piece structure. The invention mainly aims to reduce the volume and mass of the existing off-circuit tap-changer, reduce the process and material cost, improve the current-carrying capacity of the tap-changer, optimize the structural performance of the tap-changer, reduce the use and maintenance cost of the tap-changer, and further improve the economic benefit and stability of a power distribution network.

Description

Technical Field

[0001] The invention belongs to the technical field of off-excitation tap changers, and in particular relates to a compact sheet-type contact structure and an off-excitation tap changer containing the structure. Background Art

[0002] The off-excitation tap changer is a type of transformer switch, suitable for three-phase oil-immersed transformers with a rated voltage of 10KV and a rated current of 63A or less or 125A. Under off-excitation conditions, the secondary voltage can be adjusted by changing the number of turns of the transformer primary coil.

[0003] The existing off-excitation tap changer includes a stationary contact and a moving contact connected between two adjacent stationary contacts. The stationary contact is mostly in the shape of a plate, and the moving contact is mostly in the shape of a long column. The long columnar moving contact is reliably in contact with the stationary contact through the action of a spring. When changing the gear, the moving contact overcomes the spring pressure and moves up and down along the arrangement direction of the stationary contact under the action of the main shaft and the support. The gear switching is achieved by changing the connection of the stationary contacts at different positions. The long columnar moving contact is arranged on the columnar support along the circumferential direction, and a spring is arranged between the moving contact and the support.

[0004] The current carrying capacity of the tap changer is mainly related to the number of contact points between the moving contact and the static contact. Therefore, when the tap changer with the above contact structure has a large current carrying capacity requirement, in order to increase the number of contact points between the moving contact and the static contact, it is necessary to increase the volume of the columnar support so as to configure more moving contact installation positions. The increase in the volume of the columnar support requires the corresponding static contact to be increased accordingly. With the continuous increase in current carrying capacity, the volume of the tap changer body increases directly, which increases the structural difficulty of the switch and reduces the rigidity of the body. Since the static contact connection points are arranged circumferentially, the range of the live body of the switch body is expanded circumferentially, occupying a large amount of the internal space of the transformer. When used in a high-voltage field strength environment, a shielding ring device must also be added, which further increases the volume of the switch body and further occupies the internal space of the transformer, thereby increasing the manufacturing cost of the transformer box, increasing the amount of transformer oil used, and increasing the transportation cost, resulting in a large waste of resources. Summary of the invention

[0005] The purpose of the present invention is to provide a compact sheet contact structure with small size, light weight, smaller installation space, good contact performance and more contact points to achieve higher current carrying capacity, and a non-excitation tap changer based on the compact sheet contact structure, based on the current situation.

[0006] To achieve the above purpose, the present invention adopts the following technical solution.

[0007] A compact sheet contact structure, comprising a stationary contact 1, a support assembly 2, and a moving contact assembly 3;

[0008] There are multiple static contacts 1 and they are arranged in pairs along the vertical direction. The static contacts 1 are annular and include horizontal contact sections 1a on the front and rear sides and connecting sections 1b on the left and right sides.

[0009] The support assembly 2 includes a guide rod 20 and a side rod 21; the guide rod 20 is vertically arranged and inserted into the center of each static contact 1; a plurality of side rods 21 are vertically arranged and are insulated and connected to each static contact 1 respectively;

[0010] The moving contact assembly 3 includes a support member 30, a moving contact group 31, and a spring group 32;

[0011] The support member 30 is provided with a through hole and is sleeved on the guide rod 20; the front and rear sides of the support member 30 are provided with a plurality of contact piece installation grooves 30a extending vertically, and a spring installation hole 30b is dug between the front and rear contact piece installation grooves 30a, and the spring installation hole 30b is connected with the front and rear side contact piece installation grooves 30a;

[0012] The moving contact group 31 includes a plurality of sheet-shaped moving contact pieces 310, and the moving contact pieces 310 are slidably arranged in the contact piece installation groove 30a;

[0013] The spring assembly 32 includes a plurality of springs 320 . The springs 320 are disposed in the spring mounting holes 30 b and have two ends abutting against the movable contact pieces 310 in the front and rear contact piece mounting grooves 30 a .

[0014] A further improvement or preferred embodiment of the aforementioned compact sheet contact structure is that the left and right connecting sections of the stationary contact 1 are semicircular; the side rods 21 are respectively arranged on the inner side of the stationary contact 1; and a connecting contact 1c is arranged on the front or rear side of the stationary contact 1.

[0015] As a further improvement or preferred embodiment of the aforementioned compact sheet-type contact structure, the stationary contacts 1 are arranged in pairs up and down, and the distance between each pair of stationary contacts 1 matches the height of the moving contact piece 310 .

[0016] As a further improvement or preferred embodiment of the aforementioned compact sheet-type contact structure, the support member 30 is limited by the side rod 21 to prevent rotation.

[0017] A further improvement or preferred embodiment of the aforementioned compact sheet contact structure, the support member 30 includes a sliding portion 300 located in the middle and mounting portions 301 symmetrically arranged on the left and right sides of the sliding portion 300; a screw hole matching the guide rod 20 is arranged in the middle of the sliding portion 300;

[0018] The spring mounting holes 30b are uniformly dug out from the top and bottom of the mounting portion 301 in the horizontal direction;

[0019] The front and rear ends of each spring mounting hole 30b are respectively connected to at least two movable contact piece mounting grooves 30a on the front and rear sides;

[0020] A contact piece limiting hole 30c is provided on the groove wall of the movable contact piece installation groove 30a, and strip-shaped limiting holes 310a are provided at the upper and lower ends of the movable contact piece 310;

[0021] The movable contact piece 310 is vertically inserted into the contact piece installation groove 30a, and is limited by the limiting rod inserted into the contact piece limiting hole 30c and the strip limiting hole 310c. At the same time, the front and rear movable contact pieces 310 press the spring located in the spring installation hole 30b.

[0022] As a further improvement or preferred embodiment of the aforementioned compact sheet contact structure, the guide rod 20 is an externally threaded rod, and the upper and lower sides of the support member 30 are further provided with nut seats that can be sleeved on the guide rod 20, and the two nut seats are respectively connected to the support member 30.

[0023] As a further improvement or preferred embodiment of the aforementioned compact sheet-type contact structure, the middle portion of the mounting portion 301 is a lightweight hollow structure.

[0024] As a further improvement or preferred embodiment of the aforementioned compact sheet-type contact structure, the front and rear ends of each spring mounting hole 30 b are respectively connected to the two contact mounting grooves 30 a , and the two ends of each spring respectively abut against the two moving contact pieces 310 .

[0025] The present application also provides a non-excitation tap changer with a compact sheet contact structure, which also includes an electric operating mechanism 5 and a gear box 6; the electric operating mechanism 5 is provided with an output shaft 50, and the output shaft 50 is transmission-connected to the guide rod 20 through the gear box 6.

[0026] A further improvement or preferred embodiment of the above-mentioned off-excitation tap changer further includes a transformer cover support flange 7 and a fixed insulating plate 8;

[0027] The guide rod 20 and the side rod 21 are fixed between the transformer cover support flange 7 and the fixed insulating plate 8;

[0028] The upper end of the guide rod 20 extends through the transformer cover support flange 7 and is connected to the output shaft 50 through the first gear box 60, the intermediate transmission shaft 61, and the second gear box 62; the intermediate transmission shaft 61 is horizontally arranged, and the output shaft 50 is vertically arranged.

[0029] Its beneficial effects are:

[0030] 1. The contact pieces are distributed on the opposite sides and installed vertically in sheets. More contacts can be provided in the same space to form more contact loops, effectively improving the current carrying capacity. At the same time, it has a larger heat dissipation area and smaller local current, making the electrical performance of the tap changer based on this structure better and the product use and maintenance cost lower;

[0031] 2. A spring double-sided paired contact drive structure is adopted. The contacts on both sides use the middle spring to achieve adaptive positioning. No additional positioning, fixed support, drive control and other structures are required. When the moving contacts are close, the springs can be used to achieve double-sided locking. The forces on both sides of the structure balance and offset each other. The overall structural stability is better, and the structure is simple and easy to process and manufacture. It effectively reduces the longitudinal and transverse dimensions of the switch while having better reliability. At the same time, the original spindle only needs to play a guiding role, and there is no need to control the direction and angle of the contacts, etc., which reduces the technical requirements for various structures such as the spindle in existing products.

[0032] 3. The modified tap changer contact structure has good expandability. By adopting springs of different models and types and contacts with different current carrying capacities, various combinations such as single spring one-to-two, one-to-four, double spring one-to-four, etc. can be realized to meet the different requirements of the tap changer for the current carrying capacity of the contacts and the release stability between the contacts in different occasions. It has high flexibility and is easy to expand. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the structure of an off-circuit tap-changer with a compact sheet contact structure;

[0034] Figure 2 It is a top view of the compact sheet contact structure;

[0035] Figure 3 It is the structure of the support and the schematic diagram of the installation of independent contacts;

[0036] Figure 4 is a side view of the support;

[0037] The reference numerals include:

[0038] Static contact 1, horizontal contact section 1a, connecting section 1b, support assembly 2, guide rod 20, side rod 21, moving contact assembly 3, support member 30, sliding portion 300, mounting portion 301, contact piece mounting groove 30a, spring mounting hole 30b, contact piece limiting hole 30c, moving contact group 31, moving contact piece 310, strip limiting hole 310a, spring group 32, spring 320. DETAILED DESCRIPTION

[0039] The present invention is described in detail below in conjunction with specific embodiments.

[0040] The present invention is mainly used to provide a compact sheet contact structure with simple structure, good stability and easy use, and on the basis of the structure, to provide an off-excitation tap changer with smaller occupied space, more connection contacts and greater carrying capacity. The main purpose of the present invention is to reduce the volume and weight of the existing off-excitation tap changer, reduce the process and material costs, improve the current carrying capacity of the tap changer, optimize the structural performance of the device, reduce its use and maintenance costs, and thus improve the economic benefits and stability of the distribution network.

[0041] The compact sheet contact structure of the present application and the off-excitation tap changer based on the structure are further described below in conjunction with specific implementations.

[0042] like Figure 1 as well as Figure 2 As shown, the core structure of the compact sheet contact structure of the present application mainly includes a stationary contact 1, a supporting assembly 2, and a moving contact assembly 3; the left and right connecting sections of the stationary contact 1 are semicircular; the side rods 21 are respectively arranged on the inner side of the stationary contact 1; and a connecting contact 1c is arranged on the front or rear side of the stationary contact 1.

[0043] The support assembly 2 includes a guide rod 20 and a side rod 21; the guide rod 20 is vertically arranged and inserted into the center of each static contact 1; a plurality of side rods 21 are vertically arranged and are insulated and connected to each static contact 1 respectively;

[0044] The moving contact assembly 3 includes a support member 30, a moving contact group 31, and a spring group 32;

[0045] The support member 30 is provided with a through hole and is sleeved on the guide rod 20; the front and rear sides of the support member 30 are provided with a plurality of contact piece installation grooves 30a extending vertically, and a spring installation hole 30b is dug between the front and rear contact piece installation grooves 30a, and the spring installation hole 30b is connected with the front and rear side contact piece installation grooves 30a;

[0046] The moving contact group 31 includes a plurality of sheet-shaped moving contact pieces 310, and the moving contact pieces 310 are slidably arranged in the contact piece installation groove 30a;

[0047] The spring assembly 32 includes a plurality of springs 320 . The springs 320 are disposed in the spring mounting holes 30 b and have two ends abutting against the movable contact pieces 310 in the front and rear contact piece mounting grooves 30 a .

[0048] Based on the above structure, the static contacts 1 in the present application are arranged in pairs along the vertical direction. While meeting the vertical segmented installation form of the current off-excitation tap changer, an elliptical static contact 1 design is adopted, including horizontal contact segments 1a on the front and rear sides and connecting segments 1b on the left and right sides; wherein the horizontal contact segment 1a is used as a shunt contact segment with the moving contact piece in the present application, and adopts a linear structure, which can be combined with the subsequent sheet-like moving contact piece structure to form a brush-type contact structure. On the one hand, the plate-like contact piece is used to effectively increase the number of contactable positions, and at the same time, it is convenient to more evenly distribute the current to be carried, and the distribution scheme of the moving contacts on both sides is combined, and the large section of the contact body structure that occupies the main body of the static contact piece is effectively used for current shunting, avoiding the traditional plate-like columnar contact piece structure, where the current is only concentrated on a single point or a single line, resulting in large local current carrying capacity and high heat generation. The two stages on the left and right sides constitute the passage between the contact segment and the current-carrying lead-out contact point, and the path itself is short. At the same time, combined with the horizontal contact segment, the longitudinal thickness of the static contact piece is effectively compressed, so that the longitudinal size of the tap changer based on this structure can be greatly compressed;

[0049] The front and rear horizontal contact sections, combined with the paired front and rear contact pieces and the middle spring positioning structure, change the original rotational positioning one-way locking method. The spring absorbs the force on the front and rear side contact pieces, and the overall force offsets each other. While eliminating internal stress, adaptive locking is achieved based on spring elasticity. The entire contact piece contact locking process can be completed automatically, with stable connection and high action efficiency.

[0050] The support member and the guide rod in this structure are only used as a support and positioning structure for the moving contact piece to move up and down, because the moving contact piece in this application only needs to move up and down, and does not need to be adjusted in angle like the traditional ring tap changer, so it can simplify the design and make it lighter. Based on the most common solution, a guide rod with external threads and a support member with internal threads or an internal thread nut seat can be used;

[0051] Based on the opposite side arrangement of the moving contact piece in the present application, the sheet-shaped moving contact piece is installed vertically and parallel to the left and right directions, and a large number of moving contact pieces can be flexibly configured on the length scale, while reducing the overall width size, the total number of contacts is effectively increased, providing a structural basis for a larger current carrying capacity, and using the spring bidirectional self-locking method, there is no need to set up an additional force device or locking structure. Therefore, while adopting a lighter guide rod, the support member can adopt a lightweight and small-volume structural design scheme. The support member in the present application adopts Figure 3 , Figure 4The structural design scheme shown in the figure, as shown in the figure, the spring mounting holes 30b are evenly dug out from the top and bottom of the mounting part 301 in the horizontal direction; the front and rear ends of each spring mounting hole 30b are respectively connected with at least two movable contact piece mounting grooves 30a on the front and rear sides; a contact piece limiting hole 30c is provided on the groove wall of the movable contact piece mounting groove 30a, and a strip limiting hole 310a is provided at the upper and lower ends of the movable contact piece 310; the movable contact piece 310 is vertically inserted into the contact piece mounting groove 30a, and is limited by the limiting rod inserted in the contact piece limiting hole 30c and the strip limiting hole 310c, and at the same time, the movable contact pieces 310 on the front and rear sides press the springs located in the spring mounting holes 30b.

[0052] Based on this structural design, the contacts and springs in the present application do not require any redundant fixing structural parts such as bolts under ideal installation methods. Multiple moving contacts on each side only need two common limit rods to achieve horizontal movable limit and vertical immovable limit. The springs between the moving contacts are limited by the front and rear moving contacts that have been limited, which greatly simplifies the fixed limit methods of a large number of moving contacts and springs, while providing a large number of contacts and good adaptive locking, achieving a lightweight and simple design. The entire structure is more convenient to disassemble and assemble, and maintenance is simpler, achieving the purpose of reducing costs and increasing efficiency.

[0053] On top of the aforementioned basic structure, this embodiment also includes improvements to the implementation of the following specific structures, including:

[0054] In order to ensure good contact between the moving contact piece and the stationary contact piece, and to ensure that the upper and lower stationary contact pieces can be effectively connected through the moving contact piece, when the stationary contacts 1 are arranged in pairs up and down, it is necessary to ensure that the distance between the stationary contacts 1 matches the height of the moving contact piece 310, or the stationary contacts are arranged at equal intervals. This is a special form of paired equal-distance arrangement.

[0055] In order to facilitate the connection of external current-carrying cables and the installation and maintenance of external current-carrying contacts, in this embodiment, the left and right connecting sections of the static contact 1 are set to be semicircular, and the side rods 21 are respectively set on the inner side of the static contact 1, and the external current-carrying contacts are evenly set on the front or rear side of the static contact 1.

[0056] In particular, in order to simplify the design and processing technology of the support member and facilitate its use, the support member 30 structure in this embodiment is divided into a middle sliding portion 300 and a mounting portion 301 symmetrically arranged on the left and right of the sliding portion 300; a screw hole matching the guide rod 20 is arranged in the middle of the sliding portion 300; wherein the middle portion of the mounting portion 301 is a light hollow structure. The light and simplified structural design facilitates better processing design. It is easy to know that in this application, the support member can be prevented from rotating by limiting the mutual position of the moving contact piece and the static contact piece, but under a specific contact piece arrangement structure, it may also be necessary to use a side rod or other structure to limit the support member from rotating;

[0057] As a preferred implementation scheme, in this embodiment, the front and rear ends of each spring mounting hole 30b are respectively connected to the two contact piece mounting grooves 30a, and the two ends of each spring respectively resist the two moving contact pieces 310. Based on this structure, a one-to-four effect can be achieved, and a single spring is used to control the action of four moving contact pieces to meet the requirements of eight current-carrying contacts, and the structure is stable and reliable.

[0058] Furthermore, in order to facilitate the application of a compact sheet contact structure, the present application also provides an off-excitation tap changer having a compact sheet contact structure, such as Figure 1 As shown, in addition to the aforementioned compact sheet contact structure, an electric operating mechanism 5 and a gear box 6 are also provided; wherein an output shaft 50 is provided in the electric operating mechanism 5, and the output shaft 50 is transmission-connected to the guide rod 20 through the gear box 6.

[0059] It also includes a transformer cover support flange 7 and a fixed insulating plate 8; wherein the guide rod 20 and the side rod 21 are fixed between the transformer cover support flange 7 and the fixed insulating plate 8;

[0060] The upper end of the guide rod 20 extends through the transformer cover support flange 7 and is connected to the output shaft 50 through the first gear box 60, the intermediate transmission shaft 61, and the second gear box 62; the intermediate transmission shaft 61 is horizontally arranged, and the output shaft 50 is vertically arranged.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A compact contact structure, characterized in that: It comprises a stationary contact (1), a supporting assembly (2), and a moving contact assembly (3); There are a plurality of stationary contacts (1) which are arranged in pairs along the vertical direction. The stationary contacts (1) are annular and include horizontal contact sections (1a) at the front and rear sides and connecting sections (1b) at the left and right sides. The support assembly (2) comprises a guide rod (20) and a side rod (21); the guide rod (20) is vertically arranged and inserted into the center of each stationary contact (1); a plurality of side rods (21) are vertically arranged and respectively insulated and connected to each stationary contact (1); The moving contact assembly (3) comprises a support member (30), a moving contact group (31), and a spring group (32); The support member (30) is provided with a through hole and is sleeved on the guide rod (20); a plurality of contact piece installation grooves (30a) extending vertically are provided on the front and rear sides of the support member (30); a spring installation hole (30b) is dug between the front and rear contact piece installation grooves (30a); and the spring installation hole (30b) is communicated with the front and rear contact piece installation grooves (30a); The moving contact group (31) comprises a plurality of sheet-shaped moving contact pieces (310), and the moving contact pieces (310) are arranged in the contact piece installation groove (30a) so as to slide forward and backward; The spring group (32) comprises a plurality of springs (320), wherein the springs (320) are arranged in the spring installation holes (30b) and the two ends of the springs (320) abut against the movable contact pieces (310) in the front and rear contact piece installation grooves (30a).

2. The compact contact structure according to claim 1, characterized in that: The left and right connecting sections of the stationary contact (1) are semicircular; the side rods (21) are respectively arranged on the inner side of the stationary contact (1); and a connecting contact piece (1c) is arranged on the front side or the rear side of the stationary contact (1).

3. The compact contact structure according to claim 1, characterized in that: The static contacts (1) are arranged in pairs up and down, and the distance between each pair of static contacts (1) matches the height of the moving contact piece (310).

4. The compact contact structure according to claim 1, characterized in that: The support member (30) is limited by the side rod (21) to prevent rotation.

5. The compact contact structure according to claim 1, characterized in that: The support member (30) comprises a sliding portion (300) located in the middle and mounting portions (301) symmetrically arranged on the left and right sides of the sliding portion (300); a screw hole matching the guide rod (20) is arranged in the middle of the sliding portion (300), and the middle portion of the mounting portion (301) is a light hollow structure. The spring mounting holes (30b) are evenly dug out from the top and bottom of the mounting portion (301) in the horizontal direction; The front and rear ends of each spring mounting hole (30b) are respectively connected to at least two movable contact piece mounting grooves (30a) on the front and rear sides; A contact piece limiting hole (30c) is provided on the groove wall of the movable contact piece installation groove (30a), and strip-shaped limiting holes (310a) are provided at the upper and lower ends of the movable contact piece (310); The movable contact piece (310) is vertically inserted into the contact piece installation groove (30a) and is limited by a limit rod inserted into the contact piece limit hole (30c) and the strip limit hole (310c), while the front and rear movable contact pieces (310) press the spring located in the spring installation hole (30b).

6. The compact contact structure according to claim 5, characterized in that: The guide rod (20) is an externally threaded rod, and the upper and lower sides of the support member (30) are also provided with nut seats that can be sleeved on the guide rod (20), and the two nut seats are respectively connected to the support member (30).

7. The compact contact structure according to claim 5, characterized in that: The front and rear ends of each spring mounting hole (30b) are respectively connected to the two contact piece mounting grooves (30a), and the two ends of each spring respectively abut against the two movable contact pieces (310).

8. A small-volume, high-current, off-excitation tap changer having the compact contact structure of claim 1, characterized in that: It also comprises an electric operating mechanism (5) and a gear box (6); an output shaft (50) is arranged inside the electric operating mechanism (5), and the output shaft (50) is transmission-connected to the guide rod (20) through the gear box (6).

9. The small-volume, high-current off-excitation tap changer according to claim 8, characterized in that: It also includes a transformer cover supporting flange (7) and a fixed insulating plate (8); The guide rod (20) and the side rod (21) are fixed between the transformer cover support flange (7) and the fixed insulation plate (8); The upper end of the guide rod (20) passes through the transformer cover support flange (7) and then extends out to be transmission-connected with the output shaft (50) through the first gear box (60), the intermediate transmission shaft (61) and the second gear box (62); the intermediate transmission shaft (61) is arranged horizontally and the output shaft (50) is arranged vertically.

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