Fixing device for combined on-load tap-changer tap selector connecting lead

Abstract

The utility model discloses a fixing device for a combined on-load tap-changer tap selector connecting wire, which comprises a wire fixing seat and a fastening screw, a plurality of supporting parts are arranged at the bottom of the wire fixing seat, a limiting part is formed between every two adjacent supporting parts, and a guide groove for a wire to pass through is arranged between each limiting part and the corresponding supporting part; the top of the wire fixing seat is provided with an avoiding counter bore which is recessed inwards, and the center of the avoiding counter bore is provided with a threading hole. The top of the wire fixing seat is also provided with a screw joint hole, two sides of the screw joint hole are respectively provided with an oil leakage groove, and the bottom of each oil leakage groove is provided with an oil leakage hole communicated with the guide groove. And the fastening screw is screwed in the screwing hole. By adopting the fixing device provided by the utility model, under the condition that the original assembly relation is not changed, the position of the lead is fixed, accidents caused by friction are avoided, the whole structure is simple, the operation is convenient, the on-load tap-changer is ensured to meet the actual use requirement, and the fixing device is suitable for popularization and application.

Description

Technical Field

[0001] The utility model relates to the technical field of on-load tap-changers in transformers, and particularly relates to a fixing device for connecting wires of a tap selector of a combined on-load tap-changer. Background Art

[0002] On-load tap-changers are divided into two categories, namely compound type and combined type, according to the structural mode. Among them, the compound type combines the tap selector and the switching switch together, and there is only the on-load tap-changer body, while the combined type is composed of a tap selector and a switching switch. The tap selector and the switching switch of the combined on-load tap-changer are separately packed and shipped to the user, and the user assembles the tap selector and the switching switch of the combined on-load tap-changer to complete the mechanical connection and electrical connection between the tap selector and the switching switch.

[0003] The mechanical connection mode between the tap selector and the switching switch of the combined on-load tap-changer is as follows: the gear coupler at the bottom of the switching switch and the rocker coupler in the grooved pulley of the tap selector are connected to transmit the rotational torque of the switching switch to the tap selector. The base at the bottom of the switching switch and the grooved pulley support on the tap selector are firmly connected by 6 screws and nuts, so as to be combined into one body.

[0004] The electrical connection method between the tap selector and the switching switch of the combined on-load tap-changer is as follows: The tap selectors of on-load tap-changers commonly used at home and abroad all adopt sleeve shaft arrangement, and there are two "sleeving methods" according to their sleeve shaft methods. One is the inner sleeve method, where the rotating shaft is inside the lead-out ring, and the lead-out wires on the ring are radially led to the outside through the tap selector, forming a structure of "inner sleeve and outer lead". It is mainly used for D-connected tap-changers with higher insulation requirements. In this way, the lead-out wires are led out from the fixed position on the side of the tap selector. Since the connection positions of the switching switch are six positions distributed at a certain angle in a circle, the upper and lower ends of the connection wires are distributed at different circumferential angle positions, so the shaping of the wires is complex. The connection wires cannot be directly fixed in the tap selector. When making the electrical connection between the tap selector and the switching switch, connection bolts need to be used on the tap selector and the switching switch respectively to fasten the two ends of the connection wires to achieve the electrical connection between the tap selector and the switching switch. The other is the outer sleeve method, where the rotating shaft is outside the lead-out ring, and the lead wires on the ring are led out from inside the ring, forming a structure of "outer sleeve and inner lead". It is mainly used for Y-connected tap-changers with lower insulation requirements. In this way, the lead-out wires are led out from the center of the tap selector. The lower end of the connection wire is directly fixed on the central lead-out ring, the wire passes through the center of the selector, runs from the top of the tap selector, and then passes through the gap between the switching switch and the tap selector and is led out to the outside. When turning from the central position to the outside, since the connection positions of the switching switch are six positions distributed at a certain angle in a circle, the wire can be directly led out at the circumferential position and the circumferential position of the switching switch, that is, the other end of the wire can be directly fastened to the static contact on the switching switch through bolts. The shaping of its wires is simple and convenient for installation.

[0005] For the combined on-load tap-changers produced by on-load tap-changer manufacturers at home and abroad, the number of those adopting the structure of "outer sleeve and inner lead" is very small, and most of them adopt the structure of "outer sleeve and inner lead". The connection wires between the switching switch and the tap selector will pass through the gap between the switching switch and the tap selector, and there is a bevel gear for power transmission at this gap position. The connection wires and the metal parts at this position are not at the same potential, so a certain insulation distance needs to be reserved between the connection wires and the bevel gear or metal parts to ensure the insulation requirements of the connection wires. The specific structure is as Figures 1 to 3 shown.

[0006] To ensure the insulation requirements for the position of the connecting wire, each on-load tap-changer manufacturer uses the method of instruction manuals. In the user manual, it is required that the user ensure the insulation distance between the two during assembly, and eye-catching labels are hung on the tap selector and the switching switch to remind the user. However, during the specific application process, when the user assembles the tap selector and the switching switch of the combined on-load tap-changer, it may not be possible to guarantee the insulation distance between the connecting wire and the bevel gear or metal parts. If the insulation distance between the connecting wire and the bevel gear or metal parts is insufficient, a discharge phenomenon will occur, resulting in a short circuit between the odd and even numbers of the on-load tap-changer, leading to the burnout of the on-load tap-changer. Furthermore, it will cause an inter-turn short circuit in the transformer winding, and ultimately lead to the burnout of the transformer coil.

[0007] By analyzing the accidents of insulation breakdown caused by friction between the connecting wire of the tap selector of the on-load tap-changer and the bevel gear of the switching switch in the existing market in the past ten years, the main reasons are as follows: dimensional errors of the connecting wire, deformation of the wire, resulting in friction between the wire and the bevel gear after the user assembles, the transformer assembly operator not paying attention to the insulation situation at this position, and incorrect wire connection positions, etc. Therefore, aiming at the accident of insulation breakdown caused by friction between the connecting wire of the tap selector of the on-load tap-changer and the bevel gear of the switching switch, in order to ensure the insulation requirements of the connecting wire, a fixing device with convenient operation is provided. By using this fixing device and installing it at the gap position, the insulation distance between the connecting wire of the tap selector of the on-load tap-changer and the bottom metal parts of the switching switch can be guaranteed, avoiding discharge due to friction, and thus preventing the problem of burnout of the on-load tap-changer. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to address the problems in the background technology. In order to ensure the insulation requirements of the connecting wire and avoid the accident of insulation breakdown caused by friction between the connecting wire of the tap selector of the on-load tap-changer and the bevel gear of the switching switch, a fixing device with a simple structure and convenient operation is provided. By using this fixing device and installing it at the gap position, the position of the wire in the tap selector is fixed, avoiding discharge due to friction, so as to ensure the normal use of the on-load tap-changer and meet the actual use requirements. Specifically, it is a fixing device for the connecting wire of the tap selector of the combined on-load tap-changer.

[0009] To solve the above technical problems, the technical solution adopted by the present utility model is as follows: A fixing device for a connecting wire of a tap selector of a combined on-load tap-changer, comprising a wire fixing base and fastening screws. The wire fixing base has an annular structure. At the bottom of the wire fixing base, there are a plurality of supporting parts. A limiting part is formed between adjacent two supporting parts. A guiding groove for the power line to pass through is also provided between the limiting part and the supporting part. At the top of the wire fixing base, there is a recessed avoidance counterbore, and a threading hole penetrating the wire fixing base is provided at the center of the avoidance counterbore. At the top of the wire fixing base, there are also screw holes corresponding to the fastening screws. On both sides of each screw hole, there is an oil leakage groove respectively, and an oil leakage hole communicating with the guiding groove is provided at the bottom of the oil leakage groove. The fastening screws are screwed into the screw holes.

[0010] Further, for a fixing device for a connecting wire of a tap selector of a combined on-load tap-changer according to the present utility model, there are three supporting parts. The three supporting parts are arranged in a ring shape evenly at the bottom of the wire fixing base. The height of the limiting part between adjacent two supporting parts is less than the height of the supporting part. The guiding groove is arranged in an arc groove structure recessed inward.

[0011] Further, for a fixing device for a connecting wire of a tap selector of a combined on-load tap-changer according to the present utility model, there are three fastening screws. At the top of the wire fixing base, there are three screw holes corresponding to the fastening screws. The three screw holes are arranged in a ring shape evenly in the wire fixing base outside the avoidance counterbore. The oil leakage grooves on both sides of the screw holes are distributed in a ring shape evenly in the wire fixing base. A bushing matching with the fastening screw is arranged in the screw hole. The fastening screw is screwed into the screw hole in the wire fixing base through the bushing and extends downward to the outside of the wire fixing base.

[0012] Further, for a fixing device for a connecting wire of a tap selector of a combined on-load tap-changer according to the present utility model, there are also a plurality of exhaust holes penetrating the wire fixing base at the top of the wire fixing base. The plurality of exhaust holes are arranged in a ring shape in the wire fixing base outside the avoidance counterbore.

[0013] Further, for a fixing device for a connecting wire of a tap selector of a combined on-load tap-changer according to the present utility model, there are six exhaust holes. The six exhaust holes are divided into three groups. Each group consists of two exhaust holes. A group of staggered exhaust holes is provided between adjacent two oil leakage grooves. One of the exhaust holes is in the wire fixing base close to the avoidance counterbore side, and the other exhaust hole is in the wire fixing base far from the avoidance counterbore side.

[0014] Furthermore, a fixing device for connecting wires of a tap selector of a combined on-load tap-changer according to the present utility model is adopted. The wire fixing seat is made of a high-temperature resistant insulating material as an integral structure.

[0015] Adopt a fixing device for connecting wires of a tap selector of a combined on-load tap-changer according to the present utility model. The wire fixing seat made of a high-temperature resistant insulating material is installed at the insulation distance between the existing connecting wire and the bevel gear or metal part. Since a guiding groove matching the wire bending position is provided in the wire fixing seat, and an avoiding counterbore is provided at the top of the wire fixing seat, through the configured guiding groove, the wire can be stuck in the guiding groove, and problems such as upward movement, backward movement, and large-amplitude left and right swing will not occur; and through the configured avoiding counterbore, not only can the problem of the wire moving towards the center direction and colliding with the bevel gear of the switching switch be avoided, but also the structure can be made more compact. In addition, since an oil leakage hole communicating with the guiding groove is provided at the bottom of the oil leakage groove, and a plurality of exhaust holes penetrating through the wire fixing seat are also provided at the top of the wire fixing seat, the oil leakage hole and the exhaust hole are used for exhausting gas to avoid affecting the insulation performance of the wire fixing seat installed in the transformer oil due to gas.

[0016] It can be seen that by adopting the fixing device of the present utility model, without changing the original assembly relationship, the fixing device is directly installed at the original gap position, so that the position of the wire in the tap selector is fixed, and problems such as upward movement, backward movement, and large-amplitude left and right swing will not occur, ensuring the insulation distance between the connecting wire of the tap selector of the on-load tap-changer and the bottom metal part of the switching switch, completely avoiding major transformer accidents caused by friction between the connecting wire and the bevel gear of the switching switch. Its overall structure is simple, the operation is convenient, ensuring that the on-load tap-changer can be used normally to meet the actual use requirements, and is suitable for popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present utility model will be further described in detail below with reference to the accompanying drawings.

[0018] Figure 1 is a schematic diagram of the overall connection structure between the existing tap selector and the switching switch;

[0019] Figure 2 is a three-dimensional structure diagram of the existing tap selector and the connecting wire;

[0020] Figure 3 is Figure 2 the top view of

[0021] Figure 4 is a three-dimensional structure diagram of the wire fixing seat of the present utility model;

[0022] Figure 5 is Figure 4 a schematic side view structure diagram;

[0023] Figure 6 is a schematic diagram of the position structure of the connecting wire after being assembled with the fixing device described in the present utility model;

[0024] Figure 7 is a schematic diagram of a partial structure after being assembled with the fixing device described in the present utility model;

[0025] Figure 8 is a schematic diagram of the overall structure after being assembled with the fixing device described in the present utility model.

[0026] As shown in the figure: 1 - wire fixing seat, 11 - support part, 12 - limiting part, 13 - guiding groove, 14 - avoiding counterbore, 15 - wire passing hole, 16 - screw connection hole, 17 - oil leakage groove, 18 - oil leakage hole, 19 - exhaust hole, 2 - fastening screw, 3 - bushing. Specific embodiments

[0027] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model. Embodiment 1

[0028] Such as Figure 4 and Figure 5As shown in the figure, this embodiment provides a fixing device for the connecting wire of the tap selector of a combined on-load tap-changer, which includes a wire fixing base 1 and a fastening screw 2. The wire fixing base 1 is made of a high-temperature resistant insulating material and has an annular structure. At the bottom of the wire fixing base 1, there are three supporting parts 11, and the three supporting parts 11 are evenly arranged in a ring at the bottom of the wire fixing base 1. A limiting part 12 is formed between two adjacent supporting parts 11. It is required that the height of the limiting part 12 between two adjacent supporting parts 11 is less than the height of the supporting part 11. A guiding groove 13 for the power line to pass through is also provided between the limiting part 12 and the supporting part 11. It is required that the guiding groove 13 is set as an inwardly concave arc groove structure and is matched with the existing wire bending position; at the top of the wire fixing base 1, there is an inwardly concave avoidance counterbore 14, and a wire passing hole 15 penetrating the wire fixing base 1 is provided at the center of the avoidance counterbore 14; at the top of the wire fixing base 1, there is also a screw connection hole 16 corresponding to the fastening screw 2. On both sides of the screw connection hole 16, there is an oil leakage groove 17 respectively, and an oil leakage hole 18 communicating with the guiding groove 13 is provided at the bottom of the oil leakage groove 17; the fastening screw 2 is screwed into the screw connection hole 16.

[0029] Furthermore, for the fixing device for the connecting wire of the tap selector of a combined on-load tap-changer described in this embodiment, there are three fastening screws 2, and at the top of the wire fixing base 1, there are three screw connection holes 16 corresponding to the fastening screws 2. The three screw connection holes 16 are evenly arranged in a ring in the wire fixing base 1 outside the avoidance counterbore 14; the oil leakage grooves 17 on both sides of the screw connection hole 16 are evenly distributed in a ring in the wire fixing base 1, and a bushing 3 matching the fastening screw 2 is arranged in the screw connection hole 16. The fastening screw 2 is screwed into the screw connection hole 16 in the wire fixing base 1 through the bushing 3 and extends downward to the outside of the wire fixing base 1. Embodiment 2

[0030] Based on Embodiment 1, in order to facilitate the exhaust of the fixing device placed in the transformer oil and avoid affecting the insulation performance of the wire fixing seat 1 installed in the transformer oil due to the presence of gas, a plurality of exhaust holes 19 penetrating the wire fixing seat 1 are further provided at the top of the wire fixing seat 1. The plurality of exhaust holes 19 are annularly arranged in the wire fixing seat 1 outside the avoidance counterbore 14. In the specific preparation process, according to the arrangement of the existing wires, six exhaust holes 19 are provided. The six exhaust holes 19 are divided into three groups, with each group consisting of two exhaust holes 19. A group of staggeredly arranged exhaust holes 19 is provided between two adjacent oil leakage grooves 17. One of the exhaust holes 19 is located in the wire fixing seat 1 on the side close to the avoidance counterbore 14, while the other exhaust hole 19 is located in the wire fixing seat 1 on the side far from the avoidance counterbore 14. Through the exhaust holes 19 arranged between two adjacent oil leakage grooves 17, the exhaust treatment is facilitated.

[0031] When the existing tap changer and selector switch are assembled, when the upper end of the wire is fastened at the user's place, if there are wire size deviations or wire deformations caused by other reasons, it is possible for the wire to move towards the center direction, and it is also possible to collide with the bevel gear of the selector switch, thus posing a safety hazard. At the same time, since the lower end of the connecting wire of the tap changer is fixed on the conductive ring, and the six wires are arranged in a circle in the inner circle, the wires can move towards the center and can also swing left and right in the free state. After the exposed part of the wire is integrally bent, there is also a problem that it can move upwards, resulting in poor stability after fixation.

[0032] Therefore, in order to ensure the insulation requirements of the connecting wire, a certain insulation distance needs to be reserved between the connecting wire and the bevel gear or metal parts. For the existing assembly method, a fixing device with a simple structure and convenient operation is provided. By installing this fixing device at the gap position, the position of the wire in the tap changer is fixed, avoiding discharge due to friction, so as to ensure the normal use of the on-load tap-changer and meet the actual use requirements.

[0033] Such as Figures 6 to 8As shown, in the specific application process, when using the fixing device for the connecting wires of the tap selector of the combined on-load tap-changer of the present utility model, since the wire fixing seat 1 is made of a high-temperature resistant insulating material and is provided with six guiding grooves 13 corresponding to the connecting wires therein. At the same time, an avoidance counterbore 14 corresponding to the bevel gear is provided at the top of the wire fixing seat 1, and then it is installed at the insulation distance between the existing connecting wire and the bevel gear or metal part. Since the guiding grooves 13 matching the wire bending positions are provided in the wire fixing seat 1 and the avoidance counterbore 14 is provided at the top of the wire fixing seat 1, on the premise of meeting the insulation performance, through the six configured guiding grooves 13, the six wires can be stuck in the corresponding guiding grooves 13, so that the wires will not move upward, move backward, or swing significantly left and right; at the same time, through the configured avoidance counterbore 14, not only can the problem that the wire moves toward the center and collides with the bevel gear of the change-over switch be avoided, but also the structure can be made more compact; in addition, since an oil leakage hole 18 communicating with the guiding groove 13 is provided at the bottom of the oil leakage groove 17, and a plurality of exhaust holes 19 penetrating the wire fixing seat 1 are also provided at the top of the wire fixing seat 1, the oil leakage hole 18 and the exhaust holes 19 are used for exhausting air to avoid affecting the insulation performance of the wire fixing seat 1 installed in the transformer oil due to gas; finally, through the configured fastening screws 2, three lengthened fastening screws 2 are used to replace the original screws for fastening, and a bushing 3 is added at the fastening position, which can avoid the loosening problem caused by deformation, thereby enhancing the reliability of its connection.

[0034] In summary, when using the fixing device of the present utility model, without changing the original assembly relationship, the fixing device is directly installed at the original gap position, so that the position of the wire in the tap selector is fixed, and problems such as upward movement, backward movement, and significant left and right swing will not occur, ensuring the insulation distance between the connecting wire of the tap selector of the on-load tap-changer and the metal part at the bottom of the change-over switch barrel, completely avoiding major transformer accidents caused by friction between the connecting wire and the bevel gear of the change-over switch. Its overall structure is simple and the operation is convenient, ensuring that the on-load tap-changer can be used normally to meet the actual use requirements and is suitable for popularization and application.

[0035] Other details not elaborated in the present utility model are all well-known conventional technologies in the art, so no detailed description is made.

[0036] The protection scope of the present utility model is not limited to the technical solutions disclosed in the specific implementation manners. The above is only the preferred implementation manner of the present utility model and does not limit the present utility model. Any minor modification, equivalent replacement, and improvement made based on the technical solutions of the present utility model shall be included in the protection scope of the technical solutions of the present utility model.

Claims

1. A fixing device for the connection wires of a tap selector of a combined on-load tap-changer, characterized in that: It includes a wire fixing seat (1) and a fastening screw (2). The wire fixing seat (1) has an annular structure. At the bottom of the wire fixing seat (1), there are a plurality of supporting parts (11). A limiting part (12) is formed between two adjacent supporting parts (11). A guiding groove (13) for the power line to pass through is also provided between the limiting part (12) and the supporting part (11). At the top of the wire fixing seat (1), there is a recessed avoiding counterbore (14) inward, and a threading hole (15) penetrating the wire fixing seat (1) is provided at the center of the avoiding counterbore (14). At the top of the wire fixing seat (1), there is also a screwing hole (16) corresponding to the fastening screw (2). An oil leakage groove (17) is provided on each side of the screwing hole (16), and an oil leakage hole (18) communicating with the guiding groove (13) is provided at the bottom of the oil leakage groove (17). The fastening screw (2) is screwed into the screwing hole (16).

2. The fixing device for the connecting wire of the tap selector of the combined on-load tap-changer according to claim 1, characterized in that: There are three supporting parts (11). The three supporting parts (11) are arranged in a ring shape evenly at the bottom of the wire fixing seat (1). The height of the limiting part (12) between two adjacent supporting parts (11) is less than that of the supporting part (11). The guiding groove (13) is set as an inwardly recessed arc groove structure.

3. The fixing device for the connecting wire of the tap selector of the combined on-load tap-changer according to claim 2, characterized in that: There are three fastening screws (2). At the top of the wire fixing seat (1), there are three screwing holes (16) corresponding to the fastening screws (2). The three screwing holes (16) are arranged in a ring shape evenly in the wire fixing seat (1) outside the avoiding counterbore (14). The oil leakage grooves (17) on both sides of the screwing hole (16) are distributed in a ring shape evenly in the wire fixing seat (1). A bushing (3) matching the fastening screw (2) is arranged in the screwing hole (16). The fastening screw (2) is screwed into the screwing hole (16) in the wire fixing seat (1) through the bushing (3) and extends downward to the outside of the wire fixing seat (1).

4. The fixing device for the tap selector connecting wire of the combined on-load tap-changer according to claim 3, characterized in that: At the top of the wire fixing seat (1), there are also a plurality of exhaust holes (19) penetrating the wire fixing seat (1). The plurality of exhaust holes (19) are arranged in a ring shape in the wire fixing seat (1) outside the avoiding counterbore (14).

5. The fixing device for the tap selector connecting wire of the combined on-load tap-changer according to claim 4, characterized in that: There are six exhaust holes (19). The six exhaust holes (19) are divided into three groups. Each group consists of two exhaust holes (19). A group of staggeredly arranged exhaust holes (19) is provided between two adjacent oil leakage grooves (17). One exhaust hole (19) is located in the wire fixing seat (1) on the side close to the avoiding counterbore (14), and the other exhaust hole (19) is located in the wire fixing seat (1) on the side far from the avoiding counterbore (14).

6. The fixing device for the connecting wire of the tap selector of the combined on-load tap-changer according to claim 5, characterized in that: The wire fixing seat (1) is made of a high-temperature resistant insulating material as an integral structure.

Images