A kind of small non-excitation tap-changer

Abstract

The present invention provides a small off-circuit tap changer, comprising a manual operating mechanism for manual switching and indicating gear positions, a vertically arranged central insulating transmission shaft connected to the manual operating mechanism, two supporting insulating strips vertically fixed to the bottom of the manual operating mechanism and located on either side of the central insulating transmission shaft, and at least one contact system, each consisting of a stationary contact assembly and a moving contact assembly. The stationary contact assembly is disposed below the manual operating mechanism and is semi-cylindrical, comprising two vertically parallel semi-circular insulating support plates and a plurality of vertically arranged stationary contacts. The moving contact assembly comprises a metal base, a metal support member, and at least one moving contact group. The moving contact group is disposed between the two insulating support plates and includes a moving contact conductive ring, a push rod, and a spring. The present invention features a simple structure, compact size, low manufacturing cost, and stable and reliable performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of off-circuit tap changers, and particularly relates to a small off-circuit tap changer for transformers. Background Art

[0002] Off-circuit tap changers are mainly applicable to power transformers, distribution transformers, and traction transformers with off-circuit voltage regulation, as well as industrial transformers with off-circuit voltage regulation, especially small electric furnace transformers in smelting. For example, step-up power transformers, three-winding power transformers, and distribution transformers with significant changes in the load of the medium-voltage winding and relatively stable line-end voltages mostly adopt the off-circuit voltage regulation method.

[0003] Off-circuit tap changers on the market can be divided into cage-shaped, drum-shaped, strip-shaped, disc-shaped, etc. according to their structures. The operating current and voltage of cage-shaped and drum-shaped off-circuit tap changers are relatively large. The cage-shaped off-circuit tap changer has a large volume, while the drum-shaped off-circuit tap changer has a small volume. The operating voltage and current of strip-shaped off-circuit tap changers are relatively lower, and the cost is also relatively lower. The length of the switch is generally relatively long. The operating voltage and current of disc-shaped off-circuit tap changers are relatively the smallest, and the cost is also relatively the lowest. The switch volume is also the smallest. The operating voltage is usually less than 12 kv, and the operating current is also less than 100 A. Currently, for off-circuit voltage regulation transformers on the market with an operating voltage of 12 - 35 kv and an operating current greater than 100 A, the operating current and voltage of disc-shaped off-circuit tap changers do not meet the requirements. Selecting cage-shaped or strip-shaped off-circuit tap changers requires more procurement costs, and the transformer volume is larger. Selecting drum-shaped off-circuit tap changers requires more procurement costs.

[0004] In order to save investment and avoid waste, it is necessary to develop a small off-circuit tap changer with a small volume (occupying a small space in the transformer), an operating current greater than 100 A, an operating voltage of 12 - 35 kv, and a low manufacturing cost. Summary of the Invention

[0005] To solve the above problems, the purpose of the present invention is to provide a small off-circuit tap changer with a small volume, stable and reliable performance, and low manufacturing cost, filling the market gap of off-circuit tap changers in the oil-immersed transformer market that are small in volume, have an operating voltage of 12 - 35 kv, and an operating current greater than 100 A.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A small off-circuit tap changer includes a manual operating mechanism for manual switching and indicating gear positions, and a vertically arranged central insulating transmission shaft that is transmission-connected to the manual operating mechanism. The switch is characterized by also including two supporting insulating strips vertically fixed to the bottom of the manual operating mechanism and located on either side of the central insulating transmission shaft, and at least one contact system, each contact system consisting of a static contact assembly and a moving contact assembly.

[0008] The static contact assembly is arranged below the manual operating mechanism and is semi-cylindrical, comprising two upper and lower parallel semi-circular insulating support plates and a plurality of vertically arranged static contacts; the two ends of the insulating support plates are respectively fixed on two supporting insulating strips, and the two insulating support plates are movably sleeved on the outside of the central insulating transmission shaft through their respective central preset through holes; the static contacts are evenly distributed along the arc of the insulating support plates, and the upper and lower ends of the static contacts are respectively fixed on the two insulating support plates.

[0009] The moving contact assembly includes a metal base, a metal support and at least one moving contact group; the metal base is cylindrical and is fixedly mounted on the outside of the central insulating transmission shaft; the metal support is fixed on the side wall of the metal base and is located between the two insulating support plates; the moving contact group is arranged between the two insulating support plates, and includes a moving contact conductive ring, a push rod and a spring; the moving contact conductive ring is rotatably mounted on the outside of the metal support and is located between the two insulating support plates; one end of the push rod is pressed against the inner wall of the moving contact conductive ring, and the other end is movably mounted in a through hole preset in the metal support; the spring is mounted outside the push rod, one end of the spring is in contact with the metal support, and the other end is in contact with a preset step on the push rod.

[0010] Furthermore, the contact system is three semi-cylindrical bodies arranged from top to bottom on the same side below the manual operating mechanism, and each contact system corresponds to a phase of the power supply.

[0011] Furthermore, the number of the static contacts is six and they are evenly distributed along the semicircular arc of the insulating support plate, and two adjacent static contacts are connected through the movable contact conductive ring of the movable contact group.

[0012] Furthermore, the upper and lower ends of the metal base extend into the through holes of the two insulating support plates respectively and can rotate (relatively rotate) in the through holes.

[0013] Furthermore, in order to make the relative rotation between the through hole and the metal base smoother, the metal base and the through holes of the two insulating support plates are rotatably connected via bearings or sleeves.

[0014] Furthermore, the number of the movable contact groups is two and they are stacked up and down between two insulating support plates to achieve a rated current of 200A. In addition, three movable contact conductive rings can be provided to achieve a rated current of 300A.

[0015] Furthermore, to limit the ejector rod and prevent it from deviating up and down, an annular groove is provided on the inner wall of the moving contact conductive ring, and one end of the ejector rod abuts against the annular groove on the inner wall of the moving contact conductive ring and can slide along the concave annular groove.

[0016] Furthermore, to enable the ejector rod to slide smoothly along the groove, the end of the ejector rod abutting against the groove on the inner wall of the moving contact conductive ring is a ball head.

[0017] Furthermore, the manual operating mechanism includes a flange, a central shaft, a lock and a handle; the flange is arranged above the contact system, and its bottom is fixedly connected to the tops of two support insulating strips. On the upper surface of the flange, gear display numbers are cast in the area directly above the contact system. In the center of the top of the flange, a lock sleeve is vertically provided. The inner side of the lock sleeve is provided with a central hole penetrating the flange plate, and a plurality of lock grooves are evenly provided on the outer side of the lock sleeve. The lock grooves on one side of the gear display numbers correspond one-to-one with the gear display numbers; the central shaft is sleeved in the central hole of the lock sleeve, and its lower end extends below the flange and is coaxially connected to the central insulating transmission shaft, and its upper end extends out of the upper central hole. A flat groove penetrating both sides of the central shaft is horizontally provided at the upper end of the central shaft; the lock is slidably arranged in the flat groove and both ends thereof extend out of the flat groove. At the bottom of the end of the lock facing the gear display numbers, a lock pin corresponding to the position of the lock groove is fixed. When the lock pin slides towards the lock sleeve along with the lock, the lock pin is stuck in the lock groove and points to the gear display number corresponding to the lock groove; the handle is fixedly connected to the top of the central shaft.

[0018] Furthermore, to lock the manual operating mechanism, a lock hole is provided at the end of the lock away from the gear display numbers. When the lock pin slides along with the lock and is stuck in the lock groove, the lock hole at the other end of the lock is exposed out of the flat groove. The manual operating mechanism is locked by setting a bolt or a lock in the lock hole. If a lock is hung in the lock hole, only personnel with a key can operate the manual operating mechanism.

[0019] The beneficial effects of the present invention are as follows:

[0020] The off-circuit tap-changer of the present invention has a simple structure, a small volume, a low manufacturing cost, and stable and reliable performance; it is inexpensive and can save procurement costs for transformer manufacturing. The small volume of the off-circuit tap-changer can reduce the transformer box body and reduce the use of transformer oil, saving production costs for transformer manufacturing, thereby saving resources for grid investment. It fills the market gap of off-circuit tap-changers in the oil-immersed transformer market that lack small volume, operating voltage of 12 - 35 kv, and operating current greater than 100A, provides a new off-circuit tap-changer for the market, adds an option for transformer design and manufacturing, and enriches the types of off-circuit tap-changers for transformers. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The following further describes the present invention in detail with reference to the drawings.

[0022] Figure 1 This is the front view of the small non-excitation tap-changer according to the present invention;

[0023] Figure 2 is Figure 1 the sectional view taken along A-A in

[0024] Figure 3 This is the top view of the manual operating mechanism according to the present invention;

[0025] Figure 4 is Figure 3 the sectional view taken along the direction of B-B in

[0026] Figure 5 This is the front view of the contact system according to the present invention;

[0027] Figure 6 is Figure 5 the sectional view taken along the direction of C-C in

[0028] Figure 7 This is the front view of the static contact assembly according to the present invention;

[0029] Figure 8 is Figure 7 the sectional view taken along the direction of D-D in

[0030] Figure 9 This is the right view of the moving and static contact assembly according to the present invention;

[0031] Figure 10 is Figure 9 the sectional view taken along the direction of E-E in

[0032] As shown in the figure: 1 - manual operating mechanism, 101 - flange, 1011 - gear position display number, 1012 - lock sleeve, 1013 - lock groove, 102 - central shaft, 103 - lock catch, 1031 - lock pin, 1032 - lock hole, 104 - handle, 2 - central insulating transmission shaft, 3 - support insulating strip, 4 - static contact assembly, 401 - insulating support plate, 402 - static contact, 403 - bearing or bushing, 5 - moving contact assembly, 501 - metal base, 502 - metal support, 503 - moving contact conducting ring, 5031 - annular groove, 504 - ejector rod, 5041 - step, 505 - spring. Detailed implementation manners

[0033] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The described embodiments are only part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts fall within the scope of protection of the present invention.

[0034] It should be noted that the structures, proportions, sizes, etc. shown in the drawings of this 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 limited conditions under which the present invention can be implemented. Therefore, they do not have technical essential meanings. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for the convenience of description and are not used to limit the scope under which the present invention can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope under which the present invention can be implemented.

[0035] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. Embodiment 1

[0036] As Figure 1 shown in Figure 2 This embodiment provides a small on-load tap-changer, including:

[0037] A manual operating mechanism 1, which is used to operate the on-load tap-changer to switch gears and indicate the number of tap positions of the current on-load tap-changer. As Figure 3 shown in Figure 4As shown in the figure, the manual operating mechanism 1 includes a flange 101, a central shaft 102, a latch 103, and a handle 104; the flange 101 is arranged above the contact system (in a disc structure), the flange 101 is made of a cast aluminum part, and gear position display numbers 1011 are cast in the area of the upper surface of the flange 101 directly above the contact system. The gear position display numbers 1011, such as 1, 2, 3, 4, 5, are directly cast on the surface of the flange 101, eliminating the commonly used stainless steel nameplate or the circular indicator plate set in the sealed cavity, reducing the number of parts and the manufacturing cost, and completely eliminating the problem of incorrect installation of the indicator plate; a lock sleeve 1012 is vertically provided in the center of the top of the flange 101, a central hole penetrating the flange plate is provided inside the lock sleeve 1012, and a plurality of lock grooves 1013 are evenly provided on the outside of the lock sleeve 1012. The lock grooves 1013 on one side of the gear position display numbers 1011 correspond one by one to the gear position display numbers 1011; the central shaft 102 is rotatably sleeved in the central hole of the lock sleeve 1012, the lower end of the central shaft 102 extends below the flange 101 and is coaxially connected with the central insulating transmission shaft 2 (through an elastic pin), the upper end of the central shaft 102 extends out of the upward central hole, and a flat groove penetrating both sides of the central shaft 102 is horizontally provided at the upper end of the central shaft 102; the latch 103 is slidably arranged in the flat groove and both ends of it extend out of the flat groove, the latch 103 is in a flat long strip shape, and a lock pin 1031 corresponding to the position of the lock groove 1013 is fixed at the bottom of the end of the latch 103 facing the gear position display numbers 1011. When the lock pin 1031 slides towards the lock sleeve 1012 along with the latch 103, the lock pin 1031 is stuck in the lock groove 1013 (preventing the central shaft 102 from rotating to achieve self-locking), and points to the gear position display number 1011 corresponding to the lock groove 1013. The latch 103 has the functions of a self-locking operating mechanism and gear position indication, and the latch 103 points to the gear position display number 1011 corresponding to the corresponding gear position; the handle 104 is fixedly connected to the top of the central shaft 102 through an elastic pin.

[0038] The first feature of the manual operating mechanism 1 is that a latch device is provided, which can lock the gear position after the gear shift; the second feature is that the gear position display numbers 1011 cancel the traditional nameplate form, and the gear position display numbers 1011 are directly cast at the corresponding positions on the flange 101. The advantage is that the gear position display numbers 1011 will not be damaged, the handwriting is clear, the number of nameplate parts is reduced, and the manufacturing expenditure is reduced.

[0039] The central insulating transmission shaft 2, the central insulating transmission shaft 2 is vertically arranged and axially connected (rigid connection) with the central shaft 102 of the manual operating mechanism 1. At the position corresponding to the static contact assembly 4 on the central insulating transmission shaft 2, the moving contact assembly 5 is fixed by setting a notch and a pin hole, and drives the moving contact assembly 5 to rotate.

[0040] Support insulating strip 3, there are two support insulating strips 3, and the two support insulating strips 3 are vertically fixed to the bottom of the flange 101 of the manual operating mechanism 1 by screws and are located on both sides of the central insulating transmission shaft 2.

[0041] Contact system, such as Figure 1 shown, the contact system is three semi-cylindrical bodies arranged vertically on the same side below the manual operating mechanism 1 (directly below the side of the flange 101 where the gear display number 1011 is provided), and each contact system corresponds to one phase of the power supply. As Figure 5 and Figure 6 shown, each contact system consists of a static contact assembly 4 and a moving contact assembly 5.

[0042] As Figure 7 and Figure 8 shown, the static contact assembly 4 is arranged below the manual operating mechanism 1 (directly below the side of the flange 101 where the gear display number 1011 is provided), and is generally semi-cylindrical. The static contact assembly 4 includes two insulating support plates 401 arranged parallel up and down and in a semi-circular shape and six vertically arranged static contacts 402; the two insulating support plates 401 are movably sleeved outside the central insulating transmission shaft 2 through through holes preset in their respective centers. A metal connecting block is provided on each side of the insulating support plate 401. The metal connecting blocks are sandwiched between the two insulating support plates 401 and are fixedly connected to the two insulating support plates 401 by pins. At the same time, the two metal connecting blocks are respectively fixed to the two support insulating strips 3 by screws at predetermined positions, thereby fixing the static contact assembly 4. The static contacts 402 are columnar and are evenly distributed along the semi-circular arc of the insulating support plate 401. The upper and lower ends of the static contacts 402 are respectively fixed to the two insulating support plates 401. Threads are provided at both ends of the static contacts 402 and are respectively fixed to the two insulating support plates 401 by nuts. One end of the static contact 402 is provided with a long thread, and the connection coil lead is supplied through this long thread to be electrically connected to the connection coil lead at the transformer factory.

[0043] As Figure 9 and Figure 10As shown, the moving contact assembly 5 includes a metal base 501, a metal support 502, and two moving contact groups; the metal base 501 is cylindrical, and its inner side is fixedly sleeved (sleeved and fixed) outside the central insulating transmission shaft 2 through a pin sleeve. The upper and lower ends of the metal base 501 extend into the through holes of the two insulating support plates 401 respectively and can rotate (rotate relatively) in the through holes. In order to make the relative rotation between the through holes and the metal base 501 smoother, the metal base 501 and the through holes of the two insulating support plates 401 are respectively rotatably connected through bearings or bushings; the metal support 502 is fixed on the side wall of the metal base 501 and is located between the two insulating support plates 401. The metal support 502 is generally C-shaped, and its open end faces the metal base 501 and is fixedly connected to the metal base 501; the number of the moving contact groups is two and they are stacked up and down between the two insulating support plates 401 to achieve a rated current of 200A. Each moving contact group includes a moving contact conductive ring 503, a push rod 504, and a spring 505; the moving contact conductive ring 503 is a circular rolling conductive ring. The moving contact conductive ring 503 is rotatably sleeved outside the metal support 502 and is located between the two insulating support plates 401. In order to limit the push rod 504 and prevent it from running off up and down, an annular groove 5031 is provided on the inner wall of the moving contact conductive ring 503; one end of the push rod 504 is a ball head. The ball head end of the push rod 504 abuts against the annular groove 5031 on the inner wall of the moving contact conductive ring 503 and can slide along the annular groove 5031. The other end of the push rod 504 is movably sleeved in a through hole preset in the metal support 502 (closed end); the spring 505 is sleeved outside the push rod 504. One end of the spring 505 contacts (abuts against the closed end of the metal support 502), and the other end contacts a preset step 5041 on the push rod 504 (i.e., is located between the step 5041 and the closed end of the metal support 502). The moving contact conductive ring 503 is abutted against two adjacent static contacts 402 of the static contact assembly through the spring 505 and the push rod 504 to conduct the two adjacent static contacts 402.

[0044] The working principle is as follows:

[0045] When shifting gears, such as Figure 4As shown in the figure, slide the sliding latch 103 to disengage the locking pin 1031 of the latch 103 from the locking groove 1013 on the outer side of the locking sleeve 1012, unlocking the central shaft 102 of the manual operating mechanism 1 and changing it to a rotatable state. Rotate the handle 104 to drive the central shaft 102 and the latch 103 to rotate synchronously. After rotating a certain angle, the latch 103 aligns with the gear position display number 1011 at the specified gear position on the flange 101, indicating that the specified gear position has been reached. Then slide the latch 103 in the reverse direction to re-engage the locking pin 1031 of the latch 103 with the locking groove 1013 on the outer side of the locking sleeve 1012, locking the central shaft 102 to prevent it from rotating. During the above gear shifting process, the operating process of the contact system is as follows: while the central shaft 102 rotates, it drives the central insulating transmission shaft 2 to rotate synchronously. The central insulating transmission shaft 2 then drives the metal base 501, the metal support 502, the moving contact conducting ring 503, and the ejector rod 504 to rotate. The ejector rod 504 is pressed back and compresses the spring 505 by the moving contact conducting ring 503 while rotating. After the moving contact conducting ring 503 passes the highest point of the static contact 402, it continues to rotate to reach the next gear position. The spring 505 presses the ejector rod 504, and the ejector rod 504 presses the moving contact conducting ring 503 against two adjacent static contacts 402 at the next gear position to achieve gear shifting.

[0046] The characteristics of the small off-circuit tap-changer described in this embodiment are that its overall shape (except for the flange 101) is set as a semi-cylindrical shape, while the overall shape of the conventional off-circuit tap-changer is usually designed as a cylindrical shape. According to the design characteristics of the off-circuit tap-changer described in this embodiment, the number of tap positions is 5, the current is 200 - 300A, and the voltage level is 12 - 35kV. There is no need to adopt a circular arrangement at all. In this way, the external dimensions of the off-circuit tap-changer can be reduced, the waste of materials can be reduced, the space of the transformer box for transformer installation and testing can be saved, the use of transformer oil can be reduced, and thus the production and manufacturing costs of the off-circuit tap-changer and its transformer can be saved. Embodiment 2

[0047] The difference between this embodiment and Embodiment 1 is that:

[0048] The number of the moving contact groups can also be three and they are stacked vertically between the two insulating support plates 401, that is, 3 moving contact conducting rings 503 are provided to achieve a rated current of 300A. Embodiment 3

[0049] The difference between this embodiment and Embodiment 1 is that:

[0050] In order to further lock the manual operating mechanism 1, a lock hole 1032 is provided at one end of the lock catch 103 away from the gear display number 1011. After the lock pin 1031 slides along with the lock catch 103 and is stuck in the lock groove 1013, the lock hole 1032 at the other end of the lock catch 103 exposes a flat groove. By hanging a lock in the lock hole 1032, the handle 104 can be locked, enabling only key holders to operate the manual operating mechanism 1, preventing unauthorized personnel from operating the non-excitation tap changer, and ensuring the safe operation of the equipment.

[0051] Other details not elaborated in the present invention are all conventional technologies well known to those skilled in the art.

[0052] It should be noted that the term "comprising", "including" or any other variation is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device.

[0053] The protection scope of the present invention is not limited to the technical solutions disclosed in the specific embodiments. Any modification, equivalent replacement, improvement, etc. made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A small off-circuit tap changer comprising a manual operating mechanism for manual switching and indicating gear positions, and a central insulated transmission shaft disposed vertically and connected to the manual operating mechanism; characterized in that: It also includes two vertical support insulating slats fixed to the bottom of the manual operating mechanism and located on both sides of the central insulating transmission shaft, and at least one contact system, each contact system being composed of a static contact assembly and a moving contact assembly; The static contact assembly is arranged below the manual operating mechanism and is semi-cylindrical. It includes two parallel upper and lower semi-circular insulating support plates and a plurality of vertically arranged static contacts; both ends of the insulating support plates are respectively fixed on the two support insulating slats, and the two insulating support plates are movably sleeved outside the central insulating transmission shaft through through holes preset in their respective centers; the static contacts are evenly distributed along the arc of the insulating support plate, and the upper and lower ends of the static contacts are respectively fixed on the two insulating support plates; The moving contact assembly includes a metal base, a metal support, and at least one moving contact group; the metal base is cylindrical and sleeved outside the central insulating transmission shaft, and the upper and lower ends of the metal base respectively extend into the through holes of the two insulating support plates and can rotate in the through holes; the metal support is fixed on the side wall of the metal base and is located between the two insulating support plates; the moving contact group is arranged between the two insulating support plates and includes a moving contact conducting ring, a push rod, and a spring; the moving contact conducting ring is rotatably sleeved outside the metal support and is located between the two insulating support plates; one end of the push rod abuts against the inner wall of the moving contact conducting ring, and the other end is movably sleeved in a through hole preset in the metal support; the spring is sleeved outside the push rod, one end of the spring contacts the metal support, and the other end contacts a step preset on the push rod; an annular groove is provided on the inner wall of the moving contact conducting ring, and one end of the push rod abuts against the annular groove on the inner wall of the moving contact conducting ring and can slide along the annular groove; The manual operating mechanism includes a flange, a central shaft, a lock, and a handle; the flange is arranged above the contact system, and its bottom is fixedly connected to the tops of the two support insulating slats. Gear display numbers are cast in the area on the upper surface of the flange directly above the contact system. A lock sleeve is vertically provided in the center of the top of the flange. A central hole penetrating the flange plate is provided inside the lock sleeve, and a plurality of lock grooves are evenly provided on the outside of the lock sleeve. The lock grooves on one side of the gear display numbers correspond one by one to the gear display numbers; the central shaft is sleeved in the central hole of the lock sleeve, its lower end extends below the flange and is coaxially connected to the central insulating transmission shaft, and its upper end extends out of the central hole upward. A flat groove penetrating both sides of the central shaft is horizontally provided at the upper end of the central shaft; the lock is slidably arranged in the flat groove and both ends of it extend out of the flat groove. A lock pin corresponding to the position of the lock groove is fixed to the bottom of the end of the lock facing the gear display numbers. When the lock pin slides towards the lock sleeve along with the lock, the lock pin is stuck in the lock groove and points to the gear display number corresponding to the lock groove; the handle is fixedly connected to the top of the central shaft.

2. The on-load tap-changer without exciting current according to claim 1, characterized in that: The contact system is three semi-cylindrical bodies arranged on the same side below the manual operating mechanism from top to bottom.

3. The on-load tap-changer without exciting current according to claim 1, wherein: The number of the static contacts is six and they are evenly distributed along the semi-arc of the insulating support plate.

4. The on-load tap-changer without exciting current according to claim 1, characterized in that: The metal base and the through holes of the two insulating support plates are respectively rotatably connected through bearings.

5. The on-load tap-changer without exciting current according to claim 1, characterized in that: The number of the moving contact groups is two and they are stacked up and down between the two insulating support plates.

6. The on-load tap-changer without exciting current according to claim 1, wherein: One end of the ejector rod that abuts against the inner wall groove of the moving contact conductive ring is a spherical head.

7. The on-load tap-changer without exciting current according to claim 1, characterized in that: A lock hole is provided at one end of the latch away from the gear display number. After the lock pin slides with the latch and is stuck in the lock groove, the lock hole at the other end of the latch exposes the flat groove, and the manual operating mechanism is locked by setting a bolt or a lock in the lock hole.

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