Dry-type traction rectifier transformer

Abstract

The application relates to the technical field of traction power supply equipment, and particularly discloses a dry-type traction rectifier transformer, which comprises a transformer box body, a transformer body, a grounding row and a grounding sealing assembly. The transformer box body is provided with a high-voltage incoming line port, and the grounding sealing assembly is installed at the high-voltage incoming line port. The grounding sealing assembly comprises an isolation sleeve, a fixing ring, three rotating rings, upper and lower sealing sleeves and a conductive wire cage. After the third rotating ring is driven, the upper and lower sealing sleeves are attached to the outer sheath of a high-voltage cable, and the conductive wire cage is shrunk to clamp and fix the exposed shielding layer or the armored layer, and the conductive wire cage is in conduction with the grounding row through a conductive assembly. The structure can simultaneously complete the inlet sealing, shielding grounding and axial positioning when the high-voltage cable enters the transformer box body, reduces the damp oxidation of the exposed metal layer and the loosening of the grounding, and improves the long-term operation reliability of the incoming line end of the traction rectifier transformer.

Description

Technical Field

[0001] This invention relates to the field of traction power supply equipment technology, specifically to a dry-type traction rectifier transformer. Background Technology

[0002] Dry-type traction rectifier transformers are commonly used in DC traction power supply systems for urban rail transit, mining traction, and locomotive test lines. They convert AC power to a voltage level suitable for the input of the rectifier and work with the rectifier to form a twelve-pulse or twenty-four-pulse rectified power supply. These devices typically include a transformer housing, core, windings, high-voltage input terminals, low-voltage output terminals, temperature control and air-cooling components, etc. The high-voltage side is usually connected via a medium-voltage cable or busbar, while the low-voltage side is usually connected to the rectifier via copper busbars or flexible connections. Due to the frequent start-stop cycles, large inrush currents, and relatively complex operating environments of traction loads, the transformer input terminals must not only meet electrical insulation and wiring reliability requirements but also ensure moisture protection, dust protection, shielding continuity, and grounding stability under long-term vibration conditions.

[0003] Chinese patent document CN218497898U discloses an insulation structure for a dry-type traction rectifier transformer used in rail transit. The structure includes a protective box with an internal isolation structure comprising a pad, an upper pad, a lower pad, an upper insulating pad, and a lower insulating pad. The transformer is mounted on the pad, and the current is isolated by the insulating pad at the bottom of the pad, reducing the risk of electrical conductivity within the protective box. While this type of structure improves equipment safety from the perspectives of box support and insulation isolation, it does not provide a specific integrated structure for sealing the entrance of the high-voltage cable after it enters the box, grounding the shielding layer, and positioning the exposed cable section.

[0004] However, during the installation and long-term operation of dry-type traction rectifier transformers, high-voltage incoming cables typically need to be inserted into the high-voltage incoming cavity from the bottom or side of the enclosure before connecting to the high-voltage terminals. For high-voltage cables with shielding, armor, or metal sheaths, partial stripping of the outer sheath is required during connection, and the exposed metal layer must be reliably connected to the transformer grounding busbar. In existing construction, the inlet seals, grounding clamps, and cable positioning structures are often scattered. During on-site installation, differences in stripping length, insertion depth, or cable bending posture can easily lead to misalignment between the grounding clamp and the exposed shielding layer, resulting in localized crimping, misaligned crimping, or insufficient contact area. Simultaneously, the traction power supply equipment experiences temperature changes, fan vibration, and electromagnetic vibration during operation. Ordinary clamp or clamp-type grounding structures may loosen after long-term use, and the inlet seals may fail to cover and protect the exposed metal layer. Moisture and dust entering can easily cause oxidation of the shielding layer, increased contact resistance, and localized heating. Therefore, the relevant technology requires a dry-type traction rectifier transformer structure that can simultaneously ensure inlet sealing, shielding grounding compression, and stripping section positioning when the high-voltage cable enters the transformer enclosure. Summary of the Invention

[0005] This invention provides a dry-type traction rectifier transformer, which aims to solve the problems in related technologies, such as inconvenient positioning of exposed areas, insufficient grounding contact area, and difficulty in balancing sealing and grounding stability due to the dispersed setting of high-voltage incoming cable inlet sealing, shielding layer grounding, and cable positioning.

[0006] A dry-type traction rectifier transformer includes a transformer housing, a transformer body disposed within the transformer housing, and a grounding busbar. The transformer housing has a high-voltage inlet, and a grounding sealing assembly is provided at the high-voltage inlet for a high-voltage cable to pass through the transformer housing. The grounding sealing assembly includes an isolation sleeve and a fixed ring, a first rotating ring, a second rotating ring, a third rotating ring, a lower sealing sleeve, an upper sealing sleeve, and a conductive wire cage disposed within the isolation sleeve. The fixed ring is fixedly connected to the isolation sleeve. The lower sealing sleeve is connected between the fixed ring and the first rotating ring, and the upper sealing sleeve is connected between the second rotating ring and the third rotating ring. Between the first and second rotating rings, a conductive wire cage is connected; the lower and upper sealing sleeves are used to seal the outer sheath of the high-voltage cable, and the conductive wire cage is used to surround the exposed shielding or armor layer of the high-voltage cable and is connected to the grounding busbar through a conductive component; the third rotating ring is connected to a drive locking component, which is used to drive the third rotating ring to rotate relative to the fixed ring in the tightening direction, so that the lower and upper sealing sleeves tighten and fit the outer sheath, and the conductive wire cage contracts to clamp the exposed shielding or armor layer of the high-voltage cable. The drive locking component is also used to restrict the third rotating ring from rotating in the loosening direction in the opposite direction. The effect is that by setting a grounding sealing component at the high-voltage inlet of the dry-type traction rectifier transformer, the high-voltage cable no longer relies solely on separate rubber plugs, stuffing boxes, or glands for sealing when it enters the transformer tank, nor does it rely on independent grounding clamps to locally press the exposed shielding or armor layer. Instead, the upper and lower end seals and the middle grounding clamp are centrally arranged in the same isolation sleeve. The lower and upper sealing sleeves are located at both ends of the conductive wire cage, respectively, to seal the outer sheath from both ends. This ensures that the exposed metal layer after the outer sheath is removed is within a relatively protected grounding seal area, reducing the possibility of moisture, dust, and condensation entering the exposed area. The conductive wire cage surrounds the exposed shielding or armor layer. When contracted, it can clamp the metal layer from multiple circumferential positions, providing a larger contact range and more uniform clamping force compared to ordinary clamping, screw-type, or single-sided clamping grounding structures. The third rotating ring, acting as a unified drive end, can tighten the upper and lower sealing sleeves and clamp the conductive wire cage through rotation. This allows on-site construction personnel to complete sealing, grounding, and clamping at the high-voltage inlet, reducing deviations caused by step-by-step installation. The drive locking assembly prevents the third rotating ring from releasing in the reverse direction, ensuring that the sealing sleeve and conductive wire cage remain compressed even after transformer operation vibration, pulling disturbances, or temperature changes, improving the long-term stability of the moisture-proof seal and shielding grounding at the high-voltage inlet.

[0007] Preferably, the transformer housing includes a high-voltage inlet cavity and a winding cooling cavity, with a partition between them. A grounding sealing assembly is located on the inlet side of the high-voltage inlet cavity, and the transformer body is housed within the winding cooling cavity. The advantages are: the high-voltage inlet cavity provides relatively independent installation space for the high-voltage cable end, high-voltage terminals, and grounding sealing assembly, concentrating the exposed cable section and grounding components within the inlet-side maintenance area; the winding cooling cavity is used to house the core, windings, and air-cooling channels; the partition reduces obstruction of the winding cooling airflow after the high-voltage cable enters and lowers the possibility of moisture and dust from the inlet cavity spreading into the winding cooling cavity.

[0008] Preferably, the second rotating ring includes an upper ring and a lower ring. The lower ring is connected to the conductive wire cage, and the upper ring is connected to the upper sealing sleeve. The lower ring and the upper ring are separately configured and circumferentially connected. The advantage of this configuration is that by separating the second rotating ring into an upper ring and a lower ring, the contraction of the conductive wire cage and the tightening of the upper sealing sleeve can correspond to different connection bases. The lower ring can better adapt to the axial position changes caused by the contraction of the conductive wire cage, while the upper ring is used to stably drive the upper sealing sleeve to tighten under torsion, thereby preventing changes in the length of the conductive wire cage from directly pulling on the upper sealing sleeve.

[0009] Preferably, a rotating sleeve is rotatably installed inside the isolation sleeve. The rotating sleeve is coaxially and fixedly connected to the upper ring. The rotating sleeve is fitted around the outer circumference of the lower ring. The inner wall of the rotating sleeve has a groove extending along the axial direction of the high-voltage cable. A slider that slides along the groove is provided on the outer side of the lower ring. The rotating sleeve is used to drive the lower ring to rotate synchronously with the upper ring and allows the lower ring to move along the axial direction of the high-voltage cable. The effect is that the rotating sleeve can transmit torque in the circumferential direction, so that the lower ring rotates synchronously with the upper ring to drive the conductive wire cage to contract. At the same time, the groove and slider allow the lower ring to move along the axial direction of the high-voltage cable, compensating for the axial shortening or positional change that may occur during the contraction of the conductive wire cage, and reducing the risk of the conductive wire cage being pulled apart, jammed, or locally deformed.

[0010] Preferably, a first torque clutch is provided between the first rotating ring and the rotating sleeve, and a second torque clutch is provided between the rotating sleeve and the third rotating ring. The disengagement torque of the first torque clutch is less than that of the second torque clutch. The first torque clutch allows the rotating sleeve to rotate relative to the first rotating ring after the lower sealing sleeve is attached to the outer sheath. The second torque clutch allows the third rotating ring to rotate relative to the rotating sleeve after the conductive wire cage clamps the exposed shielding or armor layer of the high-voltage cable. The effect is that, through the sequential action control formed by the two-stage torque clutches, when the lower sealing sleeve is not attached to the outer sheath, all rings can work together to tighten the lower sealing sleeve first. After the lower sealing sleeve reaches the sealing resistance, the first torque clutch disengages, converting the subsequent rotation into the contraction of the conductive wire cage. When the conductive wire cage clamps the exposed metal layer of the high-voltage cable, the second torque clutch disengages, allowing the third rotating ring to continue rotating relative to the rotating sleeve and tighten the upper sealing sleeve. This reduces the need for installers to judge the tightness based on experience, ensuring that the sealing and grounding clamping are completed in a set sequence.

[0011] Preferably, both the first and second torque clutch components include clutch grooves, clutch blocks, and elastic elements. The two clutch grooves are respectively disposed on the top surfaces of the first rotating ring and the upper ring, and the two clutch blocks are respectively disposed on the bottom surfaces of the rotating sleeve and the third rotating ring via corresponding elastic elements. The elastic elements are used to push the corresponding clutch blocks into the corresponding clutch grooves. The effect is that the clutch grooves, clutch blocks, and elastic elements form a simple elastic interlocking transmission relationship. When the transmitted torque does not reach the set disengagement torque, the clutch blocks remain in the clutch grooves to transmit circumferential torque. When the corresponding sealing sleeve or conductive wire cage reaches the predetermined compression state, the circumferential component force overcomes the holding force of the elastic element, and the clutch blocks exit the clutch grooves, allowing adjacent ring components to rotate relative to each other, facilitating automatic switching of subsequent tightening stages via a mechanical structure.

[0012] Preferably, the conductive component includes a conductive end ring, an elastic conductive sheet, and a grounding strip. The conductive wire cage is conductively connected to the first rotating ring. The conductive end ring is sleeved on the outer circumference of the first rotating ring and is coaxially rotatably connected to the first rotating ring. The elastic conductive sheet is installed on the inner ring surface of the conductive end ring and elastically abuts against the first rotating ring. The conductive end ring is connected to the grounding busbar through the grounding strip. The advantages are: the conductive end ring, the elastic conductive sheet, and the grounding strip form a sliding conductive path, maintaining continuous conductivity when the first rotating ring rotates or slightly moves relative to the conductive end ring. This ensures that after the conductive wire cage clamps the shielding layer or armor layer, it reliably connects to the grounding busbar via the first rotating ring, the elastic conductive sheet, the conductive end ring, and the grounding strip, avoiding entanglement, breakage, or fatigue damage caused by the grounding strip directly connecting to rotating parts.

[0013] Preferably, the inner ring surface of the conductive end ring is provided with an annular mounting groove, and multiple elastic conductive sheets are provided. These elastic conductive sheets are spaced apart along the circumference of the conductive end ring and installed within the annular mounting groove. The edge of the first rotating ring extends into the annular mounting groove, and the multiple elastic conductive sheets elastically abut against the edge of the first rotating ring. The effect is that the annular mounting groove provides a relatively stable accommodating and guiding space for the edge of the first rotating ring, and the multiple elastic conductive sheets dispersed along the circumference abut against the edge of the first rotating ring form multi-point parallel conductive contact, reducing the impact of oxidation, wear, or insufficient contact pressure at a single contact point on the overall grounding continuity.

[0014] Preferably, the drive locking assembly includes a drive ring coaxially mounted on the third rotating ring. A one-way limiting structure is installed between the drive ring and the isolation sleeve. The one-way limiting structure includes a ratchet ring, a pawl, and a torsion spring. The ratchet ring is disposed on the drive ring, and the pawl is rotatably mounted on the isolation sleeve. The torsion spring is used to push the pawl against the ratchet ring. The pawl allows the ratchet ring to rotate in the tightening direction and restricts the ratchet ring from rotating in the loosening direction. The effect is that the drive ring provides a force-bearing position for manual tightening or tool-driven operation, and can stably transmit external operating force to the third rotating ring; the ratchet ring and the pawl form a one-way ratchet structure, which can pass over the ratchet teeth one by one when the drive ring rotates in the tightening direction, and when the drive ring has a tendency to rotate in the reverse direction, the pawl abuts against the ratchet teeth to prevent retraction, thereby maintaining the locked state of the grounding sealing assembly.

[0015] Preferably, a positioning component is provided inside the first rotating ring. The positioning component includes a positioning rod and a resetting component. One end of the positioning rod is elastically hinged to the inner side of the first rotating ring, and the other end extends toward the high-voltage cable and is used to abut against the stepped surface formed after the outer sheath is stripped. The resetting component is used to push the positioning rod to keep it in a state of close contact with the high-voltage cable, so as to restrict the high-voltage cable from continuing to move axially relative to the grounding sealing component after the positioning rod abuts against the stepped surface. The effect is that the positioning rod can elastically abut against the outer circumference of the outer sheath when the high-voltage cable is inserted. When the stepped surface of the stripped cable reaches the set position in the grounding sealing component, the positioning rod abuts against the stepped surface and restricts the high-voltage cable from continuing to move axially, so that the conductive wire cage accurately corresponds to the exposed shielding layer or armor layer, improving the consistency of the on-site stripping section positioning and grounding clamping position.

[0016] The beneficial effects of adopting the above technical solution are as follows: This invention integrates the high-voltage inlet sealing, the grounding crimping of the exposed shielding or armor layer, and the positioning of the stripped section of the high-voltage cable into the same grounding sealing assembly. The lower and upper sealing sleeves seal both ends of the outer sheath, and the exposed metal layer in the middle is circumferentially clamped by a conductive wire cage, and connected to the grounding busbar through a conductive assembly. This structure reduces installation deviations between traditional independent seals and independent grounding clamps, increases the grounding contact range of the shielding or armor layer, and reduces the risk of moisture oxidation and grounding loosening in the exposed area. The two-stage torque clutch and unidirectional limiting structure ensure sequential and sustained tightening action, facilitating on-site operation and improving the long-term operational reliability of the dry-type traction rectifier transformer inlet. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the grounding sealing assembly in this invention.

[0018] Figure 2 This is a cross-sectional view of the grounding sealing assembly of the present invention when it is not tightly attached to the high-voltage cable.

[0019] Figure 3 for Figure 2 A magnified structural diagram of point A in the middle.

[0020] Figure 4 for Figure 2 A magnified structural diagram at point B in the middle.

[0021] Figure 5 This is a schematic diagram of the grounding sealing assembly after the isolation sleeve is removed in this invention.

[0022] Figure 6 for Figure 5 A magnified structural diagram at point C.

[0023] Figure 7 This is a schematic diagram of the structure when the upper sealing sleeve is not tightly attached to the high-voltage cable in this invention.

[0024] Figure 8 This is a schematic diagram of the structure when the upper sealing sleeve is tightly attached to the high-voltage cable in this invention.

[0025] Figure label: 1. Transformer housing; 11. High-voltage inlet; 2. Grounding sealing assembly; 21. Isolation sleeve; 22. Fixing ring; 23. First rotating ring; 24. Second rotating ring; 241. Upper ring; 242. Lower ring; 2421. Slider; 25. Third rotating ring; 26. Lower sealing sleeve; 27. Upper sealing sleeve; 271. Retaining ring; 28. Conductive wire cage; 29. ​​Conductive assembly; 291. Conductive end ring; 292. Elastic conductive sheet; 293. Grounding 294. Annular mounting groove; 210. Rotating sleeve; 2101. Slide groove; 211. First torque clutch; 212. Second torque clutch; 213. Clutch groove; 214. Clutch block; 215. Elastic element; 216. Drive locking assembly; 2161. Drive ring; 2162. Ratchet ring; 2163. Anti-reverse pawl; 217. Positioning assembly; 3. High voltage cable; 31. Outer sheath; 32. Shielding layer; 33. Stepped surface. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] like Figures 1-8 As shown, a dry-type traction rectifier transformer includes a transformer housing 1, a transformer body, a grounding busbar, and a grounding sealing assembly 2. The transformer body includes an iron core and windings, used to cooperate with a rectifier to form traction rectified power supply; the grounding busbar is located inside the transformer housing 1 and is used to form a grounding connection with the shielding layer 32, armor layer, or metal sheath of the high-voltage cable 3. The transformer housing 1 is provided with a high-voltage inlet 11, and the grounding sealing assembly 2 is located at the high-voltage inlet 11, used to cooperate with the high-voltage cable 3 that enters the transformer housing 1, so that the high-voltage cable 3 can complete the inlet sealing, metal layer grounding, and stripping section positioning when entering the transformer housing 1.

[0028] The transformer housing 1 can be equipped with a high-voltage inlet cavity and a winding heat dissipation cavity. The high-voltage inlet cavity is used to install the end of the high-voltage cable 3, the high-voltage terminal block, and the grounding sealing assembly 2. The winding heat dissipation cavity is used to install the iron core, windings, and air-cooled components. A partition can be installed between the high-voltage inlet cavity and the winding heat dissipation cavity. The high-voltage inlet 11 can be located at the bottom or side of the transformer housing 1. The grounding sealing assembly 2 is fixed at the high-voltage inlet 11, allowing the high-voltage cable 3 to pass through the grounding sealing assembly 2 before entering the high-voltage inlet cavity. The low-voltage outlet can be connected to the rectifier using a copper busbar, flexible connector, or busbar. The low-voltage outlet and the grounding sealing assembly 2 in this embodiment are arranged separately to avoid the high-voltage inlet grounding structure affecting the heat dissipation and connection space of the low-voltage high-current outlet.

[0029] The grounding sealing assembly 2 includes an isolation sleeve 21, a fixing ring 22, a first rotating ring 23, a second rotating ring 24, a third rotating ring 25, a lower sealing sleeve 26, an upper sealing sleeve 27, a conductive wire cage 28, a conductive component 29, a rotating sleeve 210, a first torque clutch 211, a second torque clutch 212, a drive locking assembly 216, and a positioning assembly 217. The isolation sleeve 21 is fixed at the high-voltage inlet 11 and is used to support the rotating component, sealing component, and conductive component in the grounding sealing assembly 2. The fixing ring 22 is fixedly connected inside the isolation sleeve 21 and serves as the fixing reference for the lower sealing sleeve 26 and the first rotating ring 23. The first rotating ring 23 is rotatably disposed inside the isolation sleeve 21 and above the fixing ring 22. The second rotating ring 24 is located between the first rotating ring 23 and the third rotating ring 25. The third rotating ring 25 is located at the upper end of the grounding sealing assembly 2 and serves as the main drive input end. The lower sealing sleeve 26 is connected between the fixed ring 22 and the first rotating ring 23, the upper sealing sleeve 27 is connected between the second rotating ring 24 and the third rotating ring 25, and the conductive wire cage 28 is connected between the first rotating ring 23 and the second rotating ring 24.

[0030] Both the lower sealing sleeve 26 and the upper sealing sleeve 27 are used to seal the outer sheath 31. The lower sealing sleeve 26 and the upper sealing sleeve 27 can be cylindrical rubber sleeves, with their ends sealed to corresponding rings. A retaining ring 271 is provided on the outer side of the middle portion of both the lower sealing sleeve 26 and the upper sealing sleeve 27. The retaining ring 271 is used to limit the corresponding sealing sleeve from bulging outwards or folding outwards when twisted. One end of the lower sealing sleeve 26 is fixed to the fixing ring 22, and the other end is connected to the first rotating ring 23. When the first rotating ring 23 rotates relative to the fixing ring 22 in the tightening direction, the lower sealing sleeve 26 is twisted and tightens inwards to fit against the outer sheath 31. One end of the upper sealing sleeve 27 is connected to the second rotating ring 24, and the other end is connected to the third rotating ring 25. When the third rotating ring 25 rotates relative to the second rotating ring 24 in the tightening direction, the upper sealing sleeve 27 is twisted and tightens inwards to fit against the outer sheath 31.

[0031] The conductive wire cage 28 is located between the lower sealing sleeve 26 and the upper sealing sleeve 27, and is used to surround the exposed shielding layer 32 or armor layer of the high-voltage cable 3. When installing the high-voltage cable 3, the outer sheath 31 is pre-stripped at the position corresponding to the conductive wire cage 28, exposing the shielding layer 32 or armor layer. The conductive wire cage 28 includes multiple conductive wires, all of which extend spirally in the same direction and are arranged at intervals around the circumference of the high-voltage cable 3. Adjacent conductive wires can be staggered in axial position, so that the conductive wire cage 28 forms an interlaced support shape. One end of the conductive wire is connected to the first rotating ring 23, and the other end is connected to the second rotating ring 24. When the second rotating ring 24 rotates relative to the first rotating ring 23 in the tightening direction, the spiral angle of the multiple conductive wires changes and they converge inward, thereby clamping the exposed shielding layer 32 or armor layer of the high-voltage cable 3 from multiple circumferential positions.

[0032] The second rotating ring 24 includes an upper ring 241 and a lower ring 242. The lower ring 242 is connected to the conductive wire cage 28, and the upper ring 241 is connected to the upper sealing sleeve 27. The lower ring 242 and the upper ring 241 are separately arranged and circumferentially connected. A rotating sleeve 210 is rotatably installed inside the isolation sleeve 21. The rotating sleeve 210 is coaxially fixedly connected to the upper ring 241 and is sleeved on the outer circumference of the lower ring 242. The inner wall of the rotating sleeve 210 is provided with a groove 2101 extending along the axial direction of the high-voltage cable 3, and a slider 2421 that slides in cooperation with the groove 2101 is provided on the outer side of the lower ring 242. When the rotating sleeve 210 rotates, the lower ring 242 rotates synchronously with the upper ring 241 through the slide groove 2101 and the slider 2421; when the conductive wire cage 28 contracts and causes the lower ring 242 to have an axial displacement tendency, the slider 2421 can move along the slide groove 2101, so that the lower ring 242 moves along the axial direction of the high voltage cable 3, thereby compensating for the axial change when the conductive wire cage 28 contracts.

[0033] A first torque clutch 211 is provided between the first rotating ring 23 and the rotating sleeve 210, and a second torque clutch 212 is provided between the rotating sleeve 210 and the third rotating ring 25. The disengagement torque of the first torque clutch 211 is less than that of the second torque clutch 212. The first torque clutch 211 is used to allow the rotating sleeve 210 to rotate relative to the first rotating ring 23 after the lower sealing sleeve 26 adheres to the outer sheath 31 and generates a large rotational resistance. The second torque clutch 212 is used to allow the third rotating ring 25 to rotate relative to the rotating sleeve 210 after the conductive wire cage 28 clamps the exposed shielding layer 32 or armor layer of the high-voltage cable 3. With this arrangement, when the third rotating ring 25 is driven externally, the grounding sealing assembly 2 can sequentially complete the tightening of the lower sealing sleeve 26, the clamping of the conductive wire cage 28, and the tightening of the upper sealing sleeve 27.

[0034] Both the first torque clutch 211 and the second torque clutch 212 include a clutch groove 213, a clutch block 214, and an elastic element 215. The two clutch grooves 213 are respectively disposed on the top surfaces of the first rotating ring 23 and the upper ring 241, and the two clutch blocks 214 are respectively disposed on the bottom surfaces of the rotating sleeve 210 and the third rotating ring 25 via corresponding elastic elements 215. Since the upper ring 241 is coaxially and fixedly connected to the rotating sleeve 210, the upper ring 241 and the rotating sleeve 210 together serve as one side of the clutch base for the second torque clutch 212. The elastic element 215 pushes the corresponding clutch block 214 into the corresponding clutch groove 213, allowing adjacent rings to rotate synchronously without exceeding the disengagement torque. When the sealing sleeve 26 or the conductive wire cage 28 reaches the corresponding compression state, and torque continues to be transmitted between adjacent rings, the clutch block 214 is subjected to the circumferential component force of the side wall of the clutch groove 213 and compresses the corresponding elastic element 215. The clutch block 214 exits the clutch groove 213, causing the adjacent rings to rotate relative to each other. The disengagement torque of the first torque clutch 211 and the second torque clutch 212 can be set by adjusting the preload of the elastic element 215, the depth of the clutch groove 213, the slope angle of the clutch groove 213, or the shape of the clutch block 214.

[0035] The conductive component 29 includes a conductive end ring 291, an elastic conductive sheet 292, and a grounding strip 293. The conductive wire cage 28 is electrically connected to the first rotating ring 23. In this embodiment, the first rotating ring 23 can be a metal conductive ring. The lower end of the conductive wire cage 28 is pressed, welded, or riveted to the first rotating ring 23 for electrical connection. The conductive end ring 291 is sleeved on the outer circumference of the first rotating ring 23 and is coaxially rotatably connected to it. The elastic conductive sheet 292 is mounted on the inner ring surface of the conductive end ring 291 and elastically abuts against the first rotating ring 23. The conductive end ring 291 is connected to the grounding busbar via the grounding strip 293. Thus, after the exposed shielding layer 32 or armor layer of the high-voltage cable 3 is clamped by the conductive wire cage 28, the grounding current or induced current can be sequentially discharged through the conductive wire cage 28, the first rotating ring 23, the elastic conductive sheet 292, the conductive end ring 291, the grounding strip 293, and the grounding busbar.

[0036] The inner ring surface of the conductive end ring 291 is provided with an annular mounting groove 294. Multiple elastic conductive sheets 292 are provided, and are spaced apart along the circumference of the conductive end ring 291 within the annular mounting groove 294. The edge of the first rotating ring 23 extends into the annular mounting groove 294, and the multiple elastic conductive sheets 292 elastically abut against the edge of the first rotating ring 23. When the first rotating ring 23 rotates during the tightening phase of the lower sealing sleeve 26, the edge of the first rotating ring 23 can slide relative to the elastic conductive sheets 292, and the multiple elastic conductive sheets 292 continuously maintain elastic abutment, reducing the problem of the grounding strip 293 becoming entangled or the conductivity interrupted due to the rotation of the ring.

[0037] The drive locking assembly 216 includes a drive ring 2161 coaxially mounted on the third rotating ring 25. The drive ring 2161 may have an outer anti-slip texture, an operating hole, or a drive groove for inserting tools, facilitating manual rotation of the third rotating ring 25 by construction personnel. A one-way limiting structure is installed between the drive ring 2161 and the isolation sleeve 21. The one-way limiting structure includes a ratchet ring 2162, a stop pawl 2163, and a torsion spring. The ratchet ring 2162 is disposed on the drive ring 2161, and the stop pawl 2163 is rotatably mounted on the isolation sleeve 21. The torsion spring pushes the stop pawl 2163 to abut against the ratchet ring 2162. When the drive ring 2161 rotates in the tightening direction, the stop pawl 2163 can pass over the ratchet; when the drive ring 2161 has a tendency to rotate in the opposite direction in the loosening direction, the stop pawl 2163 abuts against the ratchet ring 2162, preventing the third rotating ring 25 from loosening in the opposite direction.

[0038] A positioning component 217 is provided inside the first rotating ring 23. The positioning component 217 includes a positioning rod and a resetting member. One end of the positioning rod is elastically hinged to the inner side of the first rotating ring 23, and the other end extends toward the high-voltage cable 3. The resetting member pushes the positioning rod to keep it in a state of close contact with the high-voltage cable 3. When the high-voltage cable 3 passes through the grounding sealing component 2, the positioning rod first abuts against the outer periphery of the outer sheath 31; when the stepped surface 33 formed after the outer sheath 31 is removed moves to the positioning rod, the free end of the positioning rod abuts against the stepped surface 33, thereby restricting the high-voltage cable 3 from continuing to move axially relative to the grounding sealing component 2. This positioning method enables the position of the conductive wire cage 28 to correspond to the exposed shielding layer 32 or armor layer of the high-voltage cable 3, reducing the problem of the conductive wire cage 28 deviating from its clamping position due to the high-voltage cable 3 being inserted too deeply or too shallowly.

[0039] Working principle: Before installation, the outer sheath 31 is stripped according to the axial length of the conductive wire cage 28, so that the high-voltage cable 3 forms an exposed shielding layer 32 or armor layer between the two sections of the outer sheath 31, and a stepped surface 33 is formed at the position where the outer sheath is stripped. The grounding sealing assembly 2 is fixed at the high-voltage inlet 11. The high-voltage cable 3 passes through the lower sealing sleeve 26, the conductive wire cage 28 and the upper sealing sleeve 27 from the outside and enters the high-voltage inlet cavity of the transformer tank 1. During the insertion of the high-voltage cable 3, the positioning rod is pressed against the outer sheath 31 under the action of the reset component. When the stepped surface 33 reaches the positioning rod, the positioning rod abuts against the stepped surface 33 and restricts the high-voltage cable 3 from continuing to move axially, so that the conductive wire cage 28 corresponds to the exposed shielding layer 32 or armor layer.

[0040] After positioning, the construction personnel rotate the drive ring 2161 in the tightening direction, which drives the third rotating ring 25 to rotate. In the initial stage, the second torque clutch 212 remains engaged, and the third rotating ring 25 drives the upper ring 241 and the rotating sleeve 210 to rotate through the second torque clutch 212; the first torque clutch 211 also remains engaged, and the rotating sleeve 210 drives the first rotating ring 23 to rotate through the first torque clutch 211. The first rotating ring 23 rotates relative to the fixed ring 22, causing the lower sealing sleeve 26 to be twisted and tightened inward until the lower sealing sleeve 26 fits against the outer sheath 31 and forms a lower end seal.

[0041] After the sealing sleeve 26 is attached to the outer sheath 31, the torque required for the first rotating ring 23 to continue rotating relative to the fixed ring 22 increases. The first torque clutch 211 reaches the disengagement torque, the clutch block 214 exits the clutch groove 213, and the rotating sleeve 210 begins to rotate relative to the first rotating ring 23. At this time, the third rotating ring 25, the upper ring 241, the rotating sleeve 210, and the lower ring 242 continue to rotate synchronously. The lower ring 242 rotates relative to the first rotating ring 23, causing the upper end of the conductive wire cage 28 to deflect circumferentially relative to the lower end. Multiple spiral conductive wires in the same direction gradually converge inward and clamp the exposed shielding layer 32 or armor layer of the high-voltage cable 3. During the contraction of the conductive wire cage 28, the lower ring 242 can move axially along the slide groove 2101 of the rotating sleeve 210 through the slider 2421 to compensate for the axial change when the conductive wire cage 28 contracts.

[0042] After the conductive wire cage 28 clamps the exposed shielding layer 32 or armor layer of the high-voltage cable 3, the torque required for the rotating sleeve 210 to continue driving the lower ring 242 to rotate further increases, and the second torque clutch 212 reaches the disengagement torque, causing the third rotating ring 25 to rotate relative to the rotating sleeve 210. After the third rotating ring 25 rotates relative to the upper ring 241, the upper sealing sleeve 27 is twisted and tightened inward until the upper sealing sleeve 27 adheres to the outer sheath 31 and forms an upper seal. At this time, the exposed shielding layer 32 or armor layer is clamped by the conductive wire cage 28 and is located within the grounding protection area formed between the upper sealing sleeve 27 and the lower sealing sleeve 26, which can reduce the entry of external moisture into the exposed area.

[0043] Throughout the tightening process, the ratchet ring 2162 rotates along the tightening direction with the drive ring 2161. The anti-reverse claw 2163 remains in contact with the ratchet ring 2162 under the action of the torsion spring and allows the ratchet ring 2162 to rotate over the teeth. When the construction personnel stop rotating the drive ring 2161, the rebound force generated by the sealing sleeve and the conductive wire cage 28 may cause the third rotating ring 25 to have a tendency to rotate in the opposite direction. The anti-reverse claw 2163 abuts against the ratchet ring 2162 and restricts its reverse rotation in the loosening direction, thereby maintaining the tightened state of the lower sealing sleeve 26, the upper sealing sleeve 27 and the conductive wire cage 28.

[0044] The grounding path is as follows: the exposed shielding layer 32 or armor layer of the high-voltage cable 3 contacts the conductive wire cage 28, the conductive wire cage 28 is conductive to the first rotating ring 23, the first rotating ring 23 is slidably conductive to the conductive end ring 291 through the elastic conductive sheet 292, and the conductive end ring 291 is connected to the grounding busbar through the grounding strip 293. Even if the first rotating ring 23 rotates during installation, the elastic conductive sheet 292 can still maintain multi-point elastic contact with the edge of the first rotating ring 23, so that the grounding path remains continuous. When disassembly or reinstallation is required, the restriction of the anti-reverse claw 2163 on the ratchet ring 2162 can be released, and the drive ring 2161 can be rotated in the loosening direction to gradually restore the upper sealing sleeve 27, the conductive wire cage 28 and the lower sealing sleeve 26 to the loosened state, and then the high-voltage cable 3 can be pulled out or the position of the high-voltage cable 3 can be readjusted.

[0045] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A dry-type traction rectifier transformer, comprising a transformer enclosure, a transformer body disposed within the transformer enclosure, and a grounding busbar, wherein the transformer enclosure is provided with a high-voltage inlet, characterized in that: A grounding sealing assembly is installed at the high-voltage inlet, which is used to allow the high-voltage cable to pass through the transformer box. The grounding sealing assembly includes an isolation sleeve and a fixed ring, a first rotating ring, a second rotating ring, a third rotating ring, a lower sealing sleeve, an upper sealing sleeve, and a conductive wire cage disposed inside the isolation sleeve. The fixed ring is fixedly connected to the isolation sleeve. The lower sealing sleeve is connected between the fixed ring and the first rotating ring, the upper sealing sleeve is connected between the second rotating ring and the third rotating ring, and the conductive wire cage is connected between the first rotating ring and the second rotating ring; The lower and upper sealing sleeves are used to seal the outer sheath of the high-voltage cable, and the conductive wire cage is used to surround the exposed shielding or armor layer of the high-voltage cable and is connected to the grounding bar through conductive components. The third rotating ring is connected to a drive locking assembly. The drive locking assembly is used to drive the third rotating ring to rotate relative to the fixed ring in the tightening direction, so that the lower sealing sleeve and the upper sealing sleeve are tightened and fit against the outer sheath, and the conductive wire cage is contracted to clamp the exposed shielding layer or armor layer of the high-voltage cable. The drive locking assembly is also used to limit the third rotating ring to rotate in the opposite direction in the loosening direction.

2. The dry-type traction rectifier transformer according to claim 1, characterized in that, The transformer housing contains a high-voltage inlet cavity and a winding heat dissipation cavity. A partition is installed between the high-voltage inlet cavity and the winding heat dissipation cavity. The grounding sealing assembly is installed on the inlet side of the high-voltage inlet cavity, and the transformer body is installed inside the winding heat dissipation cavity.

3. The dry-type traction rectifier transformer according to claim 1, characterized in that, The second rotating ring includes an upper ring and a lower ring. The lower ring is connected to the conductive wire cage, and the upper ring is connected to the upper sealing sleeve. The lower ring and the upper ring are separately set and connected by circumferential transmission.

4. The dry-type traction rectifier transformer according to claim 3, characterized in that, A rotating sleeve is rotatably installed inside the isolation sleeve. The rotating sleeve is coaxially and fixedly connected to the upper ring. The rotating sleeve is fitted around the outer circumference of the lower ring. A groove extending along the axial direction of the high-voltage cable is opened on the inner wall of the rotating sleeve. A slider that slides in cooperation with the groove is provided on the outer side of the lower ring. The rotating sleeve is used to drive the lower ring to rotate synchronously with the upper ring and allows the lower ring to move along the axial direction of the high-voltage cable.

5. The dry-type traction rectifier transformer according to claim 4, characterized in that, A first torque clutch is provided between the first rotating ring and the rotating sleeve, and a second torque clutch is provided between the rotating sleeve and the third rotating ring. The disengagement torque of the first torque clutch is less than that of the second torque clutch. The first torque clutch is used to allow the rotating sleeve to rotate relative to the first rotating ring after the lower sealing sleeve is attached to the outer sheath. The second torque clutch is used to allow the third rotating ring to rotate relative to the rotating sleeve after the conductive wire cage clamps the exposed shielding layer or armor layer of the high-voltage cable.

6. The dry-type traction rectifier transformer according to claim 5, characterized in that, Both the first torque clutch and the second torque clutch include a clutch groove, a clutch block, and an elastic element. The two clutch grooves are respectively disposed on the top surfaces of the first rotating ring and the upper ring. The two clutch blocks are respectively disposed on the bottom surfaces of the rotating sleeve and the third rotating ring through corresponding elastic elements. The elastic elements are used to push the corresponding clutch blocks into the corresponding clutch grooves.

7. The dry-type traction rectifier transformer according to claim 5, characterized in that, The conductive component includes a conductive end ring, an elastic conductive sheet, and a grounding strip. The conductive wire cage is electrically connected to the first rotating ring. The conductive end ring is sleeved on the outer circumference of the first rotating ring and is coaxially rotatably connected to the first rotating ring. The elastic conductive sheet is installed on the inner ring surface of the conductive end ring and elastically abuts against the first rotating ring. The conductive end ring is connected to the grounding bar through the grounding strip.

8. The dry-type traction rectifier transformer according to claim 7, characterized in that, The inner ring surface of the conductive end ring is provided with an annular mounting groove, and multiple elastic conductive sheets are provided. The multiple elastic conductive sheets are installed in the annular mounting groove at intervals along the circumference of the conductive end ring. The edge of the first rotating ring extends into the annular mounting groove, and the multiple elastic conductive sheets elastically abut against the edge of the first rotating ring respectively.

9. The dry-type traction rectifier transformer according to claim 1, characterized in that, The drive locking assembly includes a drive ring coaxially mounted on the third rotating ring. A one-way limiting structure is installed between the drive ring and the isolation sleeve. The one-way limiting structure includes a ratchet ring, a pawl, and a torsion spring. The ratchet ring is disposed on the drive ring, and the pawl is rotatably mounted on the isolation sleeve. The torsion spring is used to push the pawl against the ratchet ring. The pawl is used to allow the ratchet ring to rotate in the tightening direction and to limit the ratchet ring to rotate in the opposite direction in the loosening direction.

10. The dry-type traction rectifier transformer according to claim 1, characterized in that, A positioning component is provided inside the first rotating ring. The positioning component includes a positioning rod and a reset component. One end of the positioning rod is elastically hinged to the inside of the first rotating ring, and the other end extends toward the high-voltage cable and is used to abut against the stepped surface formed after the outer sheath is stripped. The reset component is used to push the positioning rod to keep it in a state of close contact with the high-voltage cable, so as to limit the high-voltage cable from continuing to move axially relative to the grounding sealing component after the positioning rod abuts against the stepped surface.

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