A ring main unit voltage transformer mounting device

Abstract

This application relates to a voltage transformer installation device for a ring main unit, comprising a mounting plate, a voltage transformer body, and fasteners. The mounting plate has a mounting cavity, within which a fixing plate is horizontally slidable. The fixing plate has multiple fixing holes, and the base of the voltage transformer body has corresponding mounting holes that mate with the fixing holes. Fasteners pass through the mounting holes and fixing holes to fix the voltage transformer body to the fixing plate. A locking block is fixedly connected to the end of the fixing plate away from the opening of the mounting cavity, and a locking groove is provided on the mounting plate to mate with the locking block. When the fixing plate slides along the mounting cavity to the installation position where the locking block is embedded in the locking groove, the voltage transformer body is in a predetermined installation position within the ring main unit. The mounting plate also includes a locking component for locking the fixing plate to the mounting plate at the installation position. Through the synergistic effect of the above components, this application effectively improves the problem of inconvenient installation and disassembly in narrow ring main units using existing installation devices.

Description

Technical Field

[0001] This application relates to the technical field of voltage transformers, and in particular to a voltage transformer installation device for a ring main unit. Background Technology

[0002] In medium-voltage power distribution systems, ring main units (RMMs), as key power equipment units, are widely used in urban power grids, industrial parks, and high-rise buildings, undertaking important functions of power distribution, control, and protection. Voltage transformers are indispensable measurement and protection components within RMMs, primarily used to provide accurate voltage signals to relay protection devices, instruments, and automation systems. The reliability and maintainability of their installation structure directly affect the operational safety and maintenance efficiency of the entire system.

[0003] Currently, voltage transformers in ring main units are mostly fixed directly to the top or bottom of the gas tank, which has the disadvantages of narrow installation space and inconvenient operation. When it is necessary to repair or replace the voltage transformer, it is often necessary to remove surrounding components, which is labor-intensive, inefficient, and even poses a risk of damaging other components or causing leakage of insulating gas in the narrow space.

[0004] Chinese patent application CN202422152833.1, in the related technology, proposes a voltage transformer installation device for a ring main unit, including a mounting plate and a transformer body. The transformer body has a sliding groove, a vertical plate is fixed to the mounting plate, and a connecting groove is provided on the vertical plate. A stop bar is slidably connected to the connecting groove and the sliding groove. A connecting plate is fixed to the mounting plate, and a sliding rod fixed to the stop bar is slidably connected to the connecting plate. The connecting plate has a limiting component for limiting the stop bar's movement. In this utility model, under the elastic force of a spring, the moving block moves until the locking rod on the moving block extends into the locking groove. At this point, the positions of the sliding rod and the stop bar are fixed, and the stop bar cannot move under force. At this point, the operator can use bolts to fix the transformer body and the mounting plate together, which is more convenient and faster. Installing bolts is also easier and simpler for the operator.

[0005] The aforementioned technologies have the following drawbacks: the installation device requires multiple steps, including pushing the stop lever, adjusting the position of the sleeve block, aligning the slot, and triggering the limit switch, before final bolt fixing can be performed. Each step is interdependent, and any misalignment can lead to locking failure. In the confined space of a ring main unit, such multi-degree-of-freedom, high-precision operations are extremely inconvenient, increasing the installation failure rate and labor burden. Furthermore, the lack of a clear unlocking mechanism and auxiliary force application structure means that maintenance requires repeated adjustments to the relative positions of components to disengage the limit switch structure, which is cumbersome. Utility Model Content

[0006] To address the inconvenience of installing and removing existing devices within narrow ring main units, this application provides a voltage transformer installation device for ring main units.

[0007] The technical solution for the installation device of a ring main unit voltage transformer provided in this application is as follows: A voltage transformer installation device for a ring main unit includes a mounting plate, a voltage transformer body, and fasteners. The mounting plate is used to fix the voltage transformer body inside the ring main unit. The mounting plate has a mounting cavity that opens to one side. A fixing plate is horizontally slidably disposed in the mounting cavity. The fixing plate has multiple fixing holes for fixing the voltage transformer body. The base of the voltage transformer body has corresponding mounting holes that mate with the fixing holes. The fasteners pass through the mounting holes and fixing holes to fix the voltage transformer body to the fixing plate. A locking block is fixedly connected to the end of the fixing plate away from the opening of the mounting cavity. The mounting plate has a locking groove that mates with the locking block. When the fixing plate slides along the mounting cavity to the mounting position where the card block is embedded in the card slot, the voltage transformer body is in the predetermined installation position inside the ring main unit; the mounting plate is also provided with a locking component for locking the fixing plate to the mounting plate at the mounting position.

[0008] Furthermore, the locking assembly includes a locking bolt, and the mounting plate has a threaded hole on its side wall perpendicular to the sliding direction that mates with the locking bolt. The fixing plate has a corresponding locking hole on its side wall. When the fixing plate slides to the installation position, the end of the locking bolt can be screwed into the locking hole to restrict the movement of the fixing plate.

[0009] Furthermore, the fixing plate has locking holes on both sides near the opening of the mounting cavity, and corresponding locking bolts are provided on both sides of the mounting plate.

[0010] Furthermore, each of the two locking bolts has a convenient operating handle fixedly connected to its nut.

[0011] Furthermore, anti-loosening washers are fitted between the contact surfaces of the two locking bolts and the mounting plate.

[0012] Furthermore, guide rails are provided on the two opposing inner sidewalls of the mounting cavity along the sliding direction, and multiple rotating shafts are fixedly connected to both sides of the fixing plate. Each rotating shaft is rotatably provided with a pulley, and the pulley is in rolling cooperation with the guide rail.

[0013] Furthermore, the fixing plate is provided with a handle for easy pulling at one end near the opening of the mounting cavity.

[0014] In summary, the beneficial technical effects of this application are as follows: 1. By pre-fixing the voltage transformer body to the fixing plate outside the cabinet to form a complete module, and then pushing the whole module into the ring main unit, the traditional mode of difficult operation in narrow cable rooms has been changed. This modular design transfers the most tedious docking and fastening work to an open space, greatly reducing the difficulty of operation. When maintenance or replacement is required, the entire module can be easily slid out by simply unlocking it, which greatly shortens the disassembly and assembly time. 2. By adopting a double-sided locking assembly, when the fixing plate slides to the predetermined position, locking bolts can be screwed in from both sides simultaneously for fixation, effectively avoiding the shaking or deflection caused by single-point locking and significantly improving seismic stability; in addition, anti-loosening washers are added under the locking bolts, which can dynamically compensate for the loss of bolt preload caused by the vibration of the ring main unit operation, preventing it from loosening, and providing the voltage transformer with a longer maintenance-free cycle and a more reliable connection operating environment; 3. By incorporating a "pulley-rail" system between the fixed plate and the mounting plate, rolling friction is replaced by sliding friction. This makes moving the heavy voltage transformer module much easier and more convenient to operate. More importantly, the rail provides precise longitudinal guidance and lateral restraint for the movement of the fixed plate, ensuring that the electrical interface of the voltage transformer accurately and repeatedly reaches the predetermined position each time, reliably connecting with the interface inside the ring main unit. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application; Figure 2 yes Figure 1 A magnified view of part A in the middle; Figure 3 This is a top view of an embodiment of this application; Figure 4 It is along Figure 3 A schematic diagram of a partial cross-sectional view of the middle BB line.

[0016] Explanation of reference numerals in the attached figures: 1. Mounting plate; 11. Mounting cavity; 111. Guide rail; 12. Threaded hole; 13. Slot; 2. Voltage transformer body; 21. Mounting hole; 22. Fastener; 3. Fixing plate; 31. Fixing hole; 32. Locking hole; 33. Rotating shaft; 34. Pulley; 35. Locking block; 36. Handle; 4. Locking bolts; 41. Operating handle; 42. Anti-loosening washers. Detailed Implementation

[0017] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] This application discloses an installation device for a voltage transformer in a ring main unit. (Refer to...) Figures 1 to 4 The device includes a mounting plate 1, a voltage transformer body 2, and fasteners 22. The mounting plate 1 is used to fix it inside the ring main unit. The mounting plate 1 has a mounting cavity 11 that opens to one side. A fixing plate 3 is horizontally slidably arranged in the mounting cavity 11. The fixing plate 3 has multiple fixing holes 31 for fixing the voltage transformer body 2. The base of the voltage transformer body 2 has corresponding mounting holes 21 that mate with the fixing holes 31. The fasteners 22 pass through the mounting holes 21 and the fixing holes 31 to fix the voltage transformer body 2 to the fixing plate 3. A locking block 35 is fixedly connected to the end of the fixing plate 3 away from the opening of the mounting cavity 11. The mounting plate 1 has a locking groove 13 that mates with the locking block 35.

[0019] When the fixing plate 3 slides along the mounting cavity 11 to the mounting position where the card block 35 is embedded in the card slot 13, the voltage transformer body 2 is in the predetermined installation position in the ring main unit; the mounting plate 1 is also provided with a locking component for locking the fixing plate 3 to the mounting plate 1 at the installation position.

[0020] Thus, the mounting plate 1, serving as the supporting base for the entire device, is formed by stamping or bending metal sheet, and its dimensions are designed according to the internal space of the ring main unit. The mounting plate 1 is fixed to a predetermined position within the ring main unit via connecting structures, such as through holes fitted with bolts. The mounting cavity 11 on the mounting plate 1 is a guide structure, with internal grooves for the horizontal sliding of the fixing plate 3. The fixing plate 3 is horizontally movable within the mounting cavity 11 via a sliding fit. The fixing plate 3 has multiple sets of fixing holes 31, the arrangement of which (e.g., spacing, layout) can be designed according to the standard interface of the base of different models of voltage transformer bodies 2 to enhance its versatility. The base of the voltage transformer body 2 has corresponding mounting holes 21 that mate with the fixing holes 31.

[0021] During assembly, the voltage transformer body 2 is first fixed to the mounting plate 3 using fasteners 22 (e.g., bolts or screws). Specifically, the fasteners 22 are passed sequentially through the mounting holes 21 on the base of the voltage transformer body 2 and the corresponding mounting holes 31 on the mounting plate 3, and tightened to securely fix the voltage transformer body 2 to the mounting plate 3, forming a movable assembly unit. Then, the assembly unit is horizontally pushed into the ring main unit along the mounting cavity 11. When the mounting plate 3 slides to the mounting position where the locking block 35 is embedded in the slot 13, the electrical interface (e.g., the test inner cone) of the voltage transformer body 2 is precisely aligned with the corresponding interface of the ring main unit. At this point, the locking assembly is used to lock the mounting plate 3 onto the mounting plate 1, preventing displacement due to vibration or misoperation during use.

[0022] This installation device, through its modular and sliding guide design, allows the voltage transformer to be pre-fixed to the mounting plate 3 outside the cabinet, forming a module that is then pushed into the cabinet as a whole. This avoids cumbersome alignment and tightening operations in confined spaces, ensuring accurate electrical interface connection. Furthermore, when maintenance or replacement of the voltage transformer is required, simply releasing the locking components allows the entire module to be easily slid out, significantly improving maintenance convenience. It effectively addresses the problem of inconvenient assembly and disassembly in narrow ring main units found with existing installation devices.

[0023] Specifically, refer to Figures 1 to 3 The locking assembly includes a locking bolt 4. The mounting plate 1 has a threaded hole 12 on its side wall perpendicular to the sliding direction, which mates with the locking bolt 4. The fixing plate 3 has a corresponding locking hole 32 on its side wall. When the fixing plate 3 slides to the installation position, the end of the locking bolt 4 can be screwed into the locking hole 32 to restrict the movement of the fixing plate 3.

[0024] When the locking bolt 4 is screwed into the locking hole 32, the end of the locking bolt 4 forms a tight mechanical fit with the inner wall of the locking hole 32, thereby constraining the fixing plate 3 in the radial direction and effectively limiting the horizontal movement of the fixing plate 3 within the mounting cavity 11. Accordingly, the fixing plate 3 is firmly locked onto the mounting plate 1, ensuring the positional stability of the voltage transformer body 2 in the installation position.

[0025] When the voltage transformer body 2 needs to be inspected or replaced, the operator first rotates the locking bolt 4 in the reverse direction so that its end exits from the locking hole 32 of the fixing plate 3, and then completely unscrews it from the threaded hole 12 of the mounting plate 1. Once the end of the locking bolt 4 is disengaged from the locking hole 32, its restriction on the movement of the fixing plate 3 is released. At this time, the operator can smoothly push the fixing plate 3, allowing it to slide with the voltage transformer body 2 within the mounting cavity 11, thereby moving it out of the installation position for subsequent operations.

[0026] Furthermore, referring to Figures 1 to 3Locking holes 32 are provided on both sides of the mounting plate 3 at the end away from the opening of the mounting cavity 11. Correspondingly, a threaded hole 12 for engaging with the locking bolt 4 is provided at the corresponding position on each side wall of the mounting plate 1. The radial constraint force generated by the ends of the locking bolts 4 on both sides and the inner wall of the locking holes 32 together forms a balanced locking torque, thereby achieving mechanical locking on both sides of the mounting plate 3 simultaneously. The dual-sided locking provides constraint force from both sides of the mounting plate 3. Compared with single-sided locking, it can effectively reduce the swaying and displacement of the mounting plate 3 in the horizontal direction, making the installation of the voltage transformer body 2 in the ring main unit more stable, especially suitable for power operation environments with high requirements for equipment stability.

[0027] Furthermore, referring to Figures 1 to 3 Both locking bolts 4 have convenient operating handles 41 fixedly connected to their nuts. These handles 41 are made of materials with sufficient mechanical strength, such as metals (e.g., steel, aluminum alloy) or engineering plastics, to ensure they are not easily deformed or damaged during repeated operation. The connection between the operating handle 41 and the nut end of the locking bolt 4 can be varied, including but not limited to welding, threaded connection, or integral molding. The operating handle 41 provides the operator with a significantly increased leverage point. During locking or unlocking, simply turning the operating handle 41 by hand easily drives the locking bolt 4 in or out, eliminating the need to find and switch to a dedicated wrench, simplifying the operation process, and shortening installation or maintenance time. Furthermore, since the internal space of ring main units is usually extremely narrow, conventional wrenches are often difficult to use. The design of the operating handle 41 optimizes the manual operating space, allowing operators to conveniently and safely apply sufficient torque to complete tightening and loosening actions even in confined environments, reducing operational difficulty and labor intensity.

[0028] Furthermore, referring to Figures 1 to 3 Anti-loosening washers 42 are fitted between the contact surfaces of the two locking bolts 4 and the mounting plate 1. The anti-loosening washers 42 are made of a variety of mature anti-loosening structures, such as, but not limited to, a combination of spring washers and flat washers or a special locking washer.

[0029] Ring main units are inevitably affected by electromagnetic forces, operational shocks, and environmental vibrations during operation. The anti-loosening washer 42 dynamically compensates for the loss of bolt preload, effectively suppressing the slight loosening tendency of the locking bolt 4 caused by long-term vibration. This ensures that the fixing plate 3 is always firmly locked in the "first position," effectively avoiding serious faults such as loose electrical connections of the voltage transformer, increased contact resistance, and even discharge caused by the displacement of the fixing plate 3, significantly improving the maintenance-free cycle and operational reliability of the entire installation device.

[0030] At the same time, refer to Figures 1 to 3Guide rails 111 are fixedly installed on the two opposing inner sidewalls of the mounting cavity 11 along the sliding direction of the fixed plate 3. The guide rails 111 are preferably made of wear-resistant, high-strength materials, such as stainless steel or surface-hardened alloy steel, to ensure resistance to deformation and wear under long-term repeated use and load-bearing conditions. The cross-section of the guide rails 111 can be designed with a contour that provides precise guidance. The guide surface that contacts the pulleys 34 is precision-machined to have low surface roughness, forming an optimized rolling contact interface. Multiple rotating shafts 33 are fixedly connected to both sides of the fixed plate 3. The number of rotating shafts 33 can be two, three, or four; in this embodiment, three are used. The installation positions of the rotating shafts 33 are precisely calculated to ensure a balanced distribution of the center of gravity of the fixed plate 3, so that the pulleys 34 on both sides are subjected to uniform force, thereby ensuring the stability of the fixed plate 3 during movement and preventing jamming or skewing. Each rotating shaft 33 has a pulley 34 rotatably mounted on its end opposite the fixed plate 3. The pulley 34 is preferably made of wear-resistant and self-lubricating engineering plastics (such as polytetrafluoroethylene, nylon 66, etc.) or composite materials to effectively reduce the rolling friction coefficient and operating noise. The pulley 34 integrates a rolling bearing (such as a deep groove ball bearing). The inner ring of this bearing mates with the rotating shaft 33, and the outer ring is interference-fitted with the hub of the pulley 34, allowing the pulley 34 to rotate flexibly and smoothly around the rotating shaft 33. The rim shape of the pulley 34 is adapted to the guide surface of the guide rail 111, forming a stable line contact or point contact to achieve precise rolling fit.

[0031] In the initial state, the operator places the fixing plate 3 at the opening of the mounting cavity 11, ensuring that the pulleys 34 on both sides of the fixing plate 3 are accurately positioned on the guide surface of the guide rail 111. After applying a horizontal thrust, the pulleys 34 begin to roll along the guide rail 111. By replacing sliding friction with rolling friction, the thrust required to move the fixing plate 3 is significantly reduced. This allows the operator to easily push the plate with less force, even after installing the heavy voltage transformer body 2, greatly reducing labor intensity and making it particularly suitable for delicate operations in space-constrained ring main units. Furthermore, the guide rail 111 not only provides support but, more importantly, provides precise longitudinal guidance and lateral restraint for the pulleys 34 (and thus the fixing plate 3). This structure effectively prevents the fixing plate 3 from shifting or wobbling during movement, ensuring that the voltage transformer body 2 can slide precisely and repeatedly to the predetermined "first position" and reliably connect with the electrical interface within the ring main unit.

[0032] Additionally, refer to Figure 1 and Figure 3A handle 36 for easy pulling is provided at one end of the fixing plate 3 near the opening of the mounting cavity 11. The handle 36 is preferably made of high-strength engineering plastic (such as polypropylene PP, nylon, etc.) and integrally molded using an injection molding process. This material selection not only ensures that the handle 36 has sufficient mechanical strength and wear resistance to withstand frequent push-pull operations, but its inherent corrosion resistance also ensures long-term stable use in complex electrical distribution environments containing moisture and chemical gases. The structure of the handle 36 is designed as a ring-shaped or bridge-like structure for easy gripping, and its contour dimensions conform to ergonomics, providing operators with a stable and comfortable grip.

[0033] The handle 36 provides the operator with a clear point of force application. When pushing the fixing plate 3 carrying the voltage transformer body 2 into or pulling out of the mounting cavity 11, the operator does not need to find other points of force in the space-constrained cabinet. They can directly and quickly apply force through the handle 36, thereby shortening the installation or maintenance time and improving the operating efficiency.

[0034] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0035] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A voltage transformer installation device for a ring main unit, comprising a mounting plate (1), a voltage transformer body (2), and fasteners (22), wherein the mounting plate (1) is used to fix it inside the ring main unit, characterized in that, The mounting plate (1) is provided with a mounting cavity (11) opening to one side. A fixing plate (3) is horizontally slidably arranged in the mounting cavity (11). The fixing plate (3) is provided with a plurality of fixing holes (31) for fixing the voltage transformer body (2). The base of the voltage transformer body (2) is provided with mounting holes (21) that cooperate with the fixing holes (31). The fastener (22) passes through the mounting holes (21) and the fixing holes (31) to fix the voltage transformer body (2) on the fixing plate (3). A locking block (35) is fixedly connected to one end of the fixing plate (3) away from the opening of the mounting cavity (11). The mounting plate (1) is provided with a locking groove (13) that cooperates with the locking block (35). When the fixing plate (3) slides along the mounting cavity (11) to the mounting position where the card block (35) is embedded in the card slot (13), the voltage transformer body (2) is in the predetermined installation position in the ring main unit; the mounting plate (1) is also provided with a locking component for locking the fixing plate (3) to the mounting plate (1) at the mounting position.

2. The installation device for a voltage transformer in a ring main unit according to claim 1, characterized in that, The locking assembly includes a locking bolt (4). The mounting plate (1) has a threaded hole (12) on its side wall perpendicular to the sliding direction that mates with the locking bolt (4). The fixing plate (3) has a corresponding locking hole (32) on its side wall. When the fixing plate (3) slides to the installation position, the end of the locking bolt (4) can be screwed into the locking hole (32) to restrict the movement of the fixing plate (3).

3. The installation device for a voltage transformer in a ring main unit according to claim 2, characterized in that, The fixing plate (3) has locking holes (32) on both sides near the opening of the mounting cavity (11), and the corresponding mounting plate (1) has locking bolts (4) on both sides.

4. The installation device for a voltage transformer in a ring main unit according to claim 3, characterized in that, Both locking bolts (4) have a convenient operating handle (41) fixedly connected to their nuts.

5. The installation device for a voltage transformer in a ring main unit according to claim 3, characterized in that, Anti-loosening washers (42) are fitted between the contact surfaces of the two locking bolts (4) and the mounting plate (1).

6. The installation device for a voltage transformer in a ring main unit according to claim 1, characterized in that, The mounting cavity (11) has guide rails (111) arranged on the two inner sidewalls opposite to each other along the sliding direction. Multiple rotating shafts (33) are fixedly connected to both sides of the fixing plate (3). Each rotating shaft (33) is rotatably provided with a pulley (34), and the pulley (34) rolls with the guide rail (111).

7. The installation device for a voltage transformer in a ring main unit according to claim 1, characterized in that, The fixing plate (3) is provided with a handle (36) at one end near the opening of the mounting cavity (11) for easy pulling.

Images