One-step grounding switch with self-locking device for isolating switch

Abstract

The invention relates to a one-step grounding switch with a self-locking device for an isolating switch. The one-step grounding switch comprises a grounding switch contact, a grounding switch contact finger and a grounding rod, the grounding rod is driven by a driving mechanism installed on the base to swing, a self-locking device is further arranged between the base and the grounding rod, the self-locking device comprises a cam arranged on the grounding rod and a clamping jaw arranged on the base, the cam acts along with the action of the grounding rod, a clamping groove for the clamping jaw to be inserted is formed in the cam, and the clamping jaw is arranged in the clamping groove. The clamping jaw is driven by a linear driver arranged on the base to move in a reciprocating mode so as to be matched with a clamping groove in the cam to achieve switching between an unlocking state and a locking state. By arranging the self-locking device between the base and the grounding rod, looseness caused by a transmission gap can be avoided, tight attachment of grounding knife contact fingers can be effectively guaranteed under the working condition of large short-circuit current, reliability during closing of a grounding knife is guaranteed, and the performance of a grounding switch product is improved.

Description

Technical Field

[0001] This invention relates to the field of disconnecting switches, and in particular to a one-step grounding switch with a self-locking device for disconnecting switches. Background Technology

[0002] The GW7 type disconnecting switch is a three-post horizontal double-break structure, which can be equipped with a grounding switch. It is mainly used in AC 50 / 60Hz power lines with a rated voltage of 40.5kV and above. It is used to disconnect or connect high-voltage circuits under no-load conditions to facilitate switching and changing the operating mode of high-voltage lines, and to provide safe electrical isolation between busbars under maintenance and high-voltage electrical equipment such as circuit breakers. The disconnecting switch consists of a base, post insulators, main conductive parts, and an attached grounding switch. Two post insulators are installed parallel to each other at both ends of the base. The middle operating insulator is mounted on a rotating bearing seat and perpendicular to the base. The main conductive parts consist of a conductive tube and a stationary contact. The stationary contact is mounted on the insulators at both ends, and the conductive tube is mounted above the middle operating insulator. After the operating insulator rotates approximately 80°, the moving contact reliably contacts the contact finger. When the disconnecting switch is equipped with a grounding switch, a reliable mechanical interlocking device should be installed between the disconnecting switch and the grounding switch to ensure that when the disconnecting switch is closed, the grounding switch cannot be closed, and vice versa.

[0003] The GW7 type disconnecting switch, as a typical open-type disconnecting switch, has a large market share. Due to its widespread application, the GW7 type disconnecting switch frequently encounters large short-circuit current conditions (up to 50kA / 1s). Under these conditions, high contact pressure is required on the contact fingers, and the overall rigidity of the grounding switch structure is also crucial; common one-step grounding switches often fail to prevent disconnection. Under the influence of a massive short-circuit current, the grounding switch experiences significant electrodynamic force, causing the contact fingers to make contact on one side or even disconnect. This leads to rapid heating and eventual melting of the conductive circuit. The grounding switch itself will be completely rendered unusable, and the disconnecting switch directly connected to it is also highly likely to be damaged due to overheating and electrodynamic forces.

[0004] Therefore, it is essential to implement dynamic and thermal design on the GW7 type disconnector switch and one-step grounding switch to ensure reliable closing and opening operations under high current conditions and improve the operational reliability of power lines.

[0005] Conventional open-type disconnect switches using one-step grounding switches have a relatively simple structure, relying solely on the contact pressure of the contacts to ensure the grounding switch is closed. Under conditions of large short-circuit current (50kA), due to the lack of a self-locking device, the transmission gap of the product itself can cause one-sided contact or disengagement of the contacts, leading to the grounding switch melting or even burning out. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a one-step grounding switch with a self-locking device for disconnecting switches that can withstand large short-circuit current conditions.

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: a one-step grounding switch with a self-locking device for disconnecting switches. The one-step grounding switch is attached to the disconnecting switch. The disconnecting switch includes a base, an insulator post set on the base, and a moving contact and a stationary contact installed on the insulator post. An mounting plate for installing the moving contact and the stationary contact is also provided at the top of the insulator post. The one-step grounding switch is installed on the side of one of the insulator posts. Its innovation is that the one-step grounding switch includes a grounding switch contact, a grounding switch contact finger, and a grounding rod. The grounding switch contact is mounted on the side of the mounting plate through the cooperation of a contact mounting base; The grounding rod is driven to swing by a drive mechanism mounted on the base. A self-locking device is also provided between the base and the grounding rod. The self-locking device includes a cam mounted on the grounding rod and a pawl mounted on the base. The cam moves with the movement of the grounding rod. A slot for inserting the pawl is opened on the cam. The pawl is driven to reciprocate by a linear driver mounted on the base, thereby cooperating with the slot on the cam to switch between the unlocked and locked states. The grounding switch contact is installed on one side of the grounding rod and swings under the action of the grounding rod, thereby moving closer to or further away from the grounding switch contact finger to achieve opening and closing of the circuit breaker.

[0008] Furthermore, a rotating shaft is connected to the side of the grounding rod away from the grounding switch contact. The two sides of the rotating shaft are mounted on the base through the cooperation of bearings and bearing seats. The rotating shaft and the grounding rod are connected through the cooperation of a fixing component. There are two cams, which are respectively set on both sides of the grounding rod. The two cams are connected to the rotating shaft through a cam sleeve. The cam sleeve is directly fitted on the outer wall of the rotating shaft and is tightened and fixed to the rotating shaft through a tightening bolt. There are also two claws, which are matched one-to-one with the two cams.

[0009] Furthermore, the fixing component includes A fixed plate has a first arc-shaped groove on one side that fits with the outer wall of the grounding rod, and a second arc-shaped groove on the other side that fits with the outer wall of the rotating shaft, with the center line of the first arc-shaped groove perpendicular to the center line of the second arc-shaped groove. After the outer wall of the grounding rod is fitted into the first arc-shaped groove, it is fixed by the cooperation of a pair of U-bolts and nuts distributed vertically. After the outer wall of the rotating shaft fits into the second arc-shaped groove, it is fixed by the cooperation of a pair of horizontally distributed connecting blocks. The connecting blocks and the fixing plate are located on both sides of the rotating shaft. A third arc-shaped groove is also opened on the side of the connecting block closer to the rotating shaft. Several toothed structures are also provided on the inner wall of the third arc-shaped groove. The two sides of the third arc-shaped groove are fixed to the fixing plate by the cooperation of connecting bolts and nuts. A through hole for the connecting bolts to pass through is also opened on the fixing plate.

[0010] Furthermore, the cooperation between the grounding switch contact finger and the contact finger mounting base is as follows: the contact finger mounting base includes a mounting base body, which is fixed to the mounting plate by a pair of bolts. The mounting base body is T-shaped, and a contact finger limiting block is installed on one side of the mounting base body. A limiting groove is opened in the middle of the contact finger limiting block. The grounding switch contact is composed of a pair of parallel elastic contact segments. The elastic contact segments are U-shaped. One side of the elastic contact segments is fixed to the mounting base body by bolts, and the other side of the elastic contact segments extends into the limiting groove of the contact limiting block. The two elastic contact segments work together to form a cavity for the grounding switch contact to be inserted, and the outside of the cavity is a V-shaped opening. The grounding switch contact is rectangular in shape, and a mounting groove for installing the grounding switch contact is opened at the end of the grounding rod. The grounding switch contact is fixed to the grounding rod by bolts.

[0011] Furthermore, a polytetrafluoroethylene (PTFE) limiting block is provided at the bottom of the mounting base body, located below the grounding switch contact finger, and a limiting groove is provided on one side of the PTFE limiting block to allow the grounding switch contact to extend into.

[0012] Furthermore, a protective plate is provided on the outer side of the elastic finger segment, and the protective plate is fixed to the mounting base body by bolts.

[0013] The advantages of this invention are as follows: By setting a self-locking device between the base and the grounding rod, loosening caused by transmission gap can be avoided. Under the condition of large short-circuit current, the contact fingers of the grounding switch can be effectively kept in close contact, ensuring the reliability of the grounding switch when closing and improving the performance of the grounding switch product.

[0014] For the design of the grounding switch contact fingers and grounding switch contacts, a grounding switch contact finger structure with two pairs of loop-shaped slots is adopted, which increases the contact area between the grounding switch contact fingers and the grounding switch contacts and ensures reliable contact; while the grounding switch contacts adopt a rectangular block structure to reduce the closing resistance; a polytetrafluoroethylene limit block is designed and installed below the grounding switch contact fingers to limit the offset of the contacts when subjected to short-circuit electrodynamic forces and avoid one-sided contact or disengagement.

[0015] The disconnecting switch of the present invention is a one-step grounding switch with a self-locking device, which has a reliable structure, simple appearance, strong manufacturability, and low cost. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a one-step grounding switch with a self-locking device for use in disconnecting switches according to the present invention.

[0017] Figure 2 This is a schematic diagram of the grounding switch contact finger in this invention.

[0018] Figure 3 This is a schematic diagram of the grounding switch contact in this invention.

[0019] Figure 4 This is a schematic diagram of the self-locking device in this invention.

[0020] Figure 5 for Figure 4 Enlarged schematic diagram of part A. Detailed Implementation

[0021] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0022] like Figures 1-5 The diagram shows a one-step grounding switch with a self-locking device for use with a disconnecting switch. The one-step grounding switch is attached to the disconnecting switch. The disconnecting switch includes a base 1, an insulator post 11 disposed on the base 1, and a moving contact 13 and a stationary contact 12 mounted on the insulator post 11. A mounting plate for mounting the moving contact 13 and the stationary contact 12 is also provided at the top of the insulator post 11. The one-step grounding switch 2 is installed on the side of one of the insulator posts 11.

[0023] The one-step grounding switch 2 includes a grounding switch contact 22, a grounding switch contact finger, and a grounding rod 21.

[0024] The grounding switch contact is mounted on the side of the mounting plate 14 through the cooperation of a contact mounting base, such as... Figure 2 , Figure 5 As shown in the schematic diagram, the cooperation between the grounding switch contact and the contact mounting base is as follows: The contact mounting base includes a mounting base body 24, which is fixed to the bottom surface of the mounting plate 14 by a pair of bolts. The mounting base body 24 is T-shaped. A contact limiting block 25 is installed on one side of the mounting base body 24. A limiting groove is opened in the middle of the contact limiting block 25. The limiting groove is a through groove that extends out of the contact limiting block 25 on both the upper and lower sides.

[0025] The grounding switch contact consists of a pair of parallel elastic contact segments 23, each U-shaped. One side of each elastic contact segment 23 is fixed to the mounting base body 24 by bolts. A protective plate 231 is also provided on the outside of each elastic contact segment 23, and is fixed to the mounting base body 24 by bolts. Several through holes for bolts are provided on both the protective plate 231 and the elastic contact segments 23. A threaded blind hole for threaded engagement with the bolts is provided on the mounting base body 24. During installation, the through holes on the protective plate 231, the through holes on the elastic contact segments 23, and the threaded blind hole on the mounting base body 24 are aligned one by one. Bolts are then passed through the through holes on the protective plate 231 and the elastic contact segments 23 sequentially from the outside in, and finally threaded into the threaded blind hole on the mounting base body 24, thus achieving the fixation between the protective plate 231, the elastic contact segments 23, and the mounting base body 24.

[0026] The other side of the elastic contact finger 23 extends into the limiting groove of the contact finger limiting block 25, and there is a certain gap between the two elastic contact finger 23 located on one side of the limiting groove. The two elastic contact finger 23 cooperate to form a cavity into which the grounding switch contact 22 can be inserted, and the outside of the cavity is a V-shaped opening.

[0027] The grounding switch contact 22 is installed on one side of the grounding rod 21 and swings under the action of the grounding rod 21, thereby moving closer to or further away from the grounding switch contact finger to achieve opening and closing of the circuit breaker.

[0028] A rotating shaft 211 is also connected to the side of the grounding rod 21 away from the grounding switch contact. The two sides of the rotating shaft 211 are mounted on the base 1 through the cooperation of bearings and bearing seats. The rotating shaft 211 and the grounding rod 21 are connected by a fixed component.

[0029] Fixed components include A fixing plate 3 is a rectangular plate. On one side of the fixing plate 3, there is a first arc-shaped groove that fits with the outer wall of the grounding rod 21. On the other side of the fixing plate 3, there is a second arc-shaped groove that fits with the outer wall of the rotating shaft 211. The center line of the first arc-shaped groove is perpendicular to the center line of the second arc-shaped groove.

[0030] After the outer wall of the grounding rod 21 is fitted into the first arc-shaped groove, it is fixed by a pair of U-bolts and nuts distributed vertically.

[0031] After the outer wall of the rotating shaft 211 is fitted with the second arc-shaped groove, it is fixed by the cooperation of a pair of horizontally distributed connecting blocks 31. The connecting blocks 31 and the fixing plate 3 are located on both sides of the rotating shaft 211. A third arc-shaped groove is also opened on the side of the connecting block 31 close to the rotating shaft 211. Several toothed structures are also provided on the inner wall of the third arc-shaped groove so that the connecting block 31 can fit better with the outer wall of the rotating shaft 211. The two sides of the third arc-shaped groove are fixed to the fixing plate by the cooperation of connecting bolts and nuts. A through hole for the connecting bolts to pass through is also opened on the fixing plate 3.

[0032] The rotating shaft 211 is driven to rotate by a drive mechanism mounted on the base 1, which in turn causes the grounding rod 21 to swing. The drive mechanism can be a separate drive mechanism mounted on the base 1, such as a motor, or it can be the operating mechanism of the disconnecting switch that drives the rotating shaft 211 to rotate through the cooperation of the linkage.

[0033] A self-locking device is also provided between the base 1 and the grounding rod 21. The self-locking device includes a cam 212 provided on the grounding rod 21 and a pawl 213 provided on the base 1.

[0034] There are two cams 212, which are respectively set on both sides of the grounding rod 21. The two cams 212 are connected to the rotating shaft 211 through the cooperation of a cam sleeve 214. The cam sleeve 214 is directly fitted on the outer wall of the rotating shaft 211 and is tightened and fixed with the rotating shaft 211 through the cooperation of a tightening bolt, so that the cam 212 can move with the movement of the grounding rod. A slot for inserting a claw 213 is opened on the cam 212.

[0035] The pawl 213 is an elongated structure, and it is driven by a linear actuator 215 mounted on the base 1 to reciprocate, thereby engaging with the slot on the cam 212 to switch between unlocked and locked states. In this embodiment, the linear actuator 215 can be a linear motor or an electric push rod. There are two pawls 213, which correspond one-to-one with the two cams 212, and each of the two pawls 213 is driven by an independent linear actuator 215 to reciprocate.

[0036] The grounding switch contact 22 is rectangular in shape. A mounting groove for installing the grounding switch contact 22 is formed at the end of the grounding rod 21. The bottom of the grounding switch contact 22 is placed within the mounting groove of the grounding rod 21 and fixed to the grounding rod 21 by bolts. The design of the grounding switch fingers and grounding switch contacts employs a two-pair loop-shaped slotted structure for the grounding switch fingers, increasing the contact area between the grounding switch fingers and the grounding switch contacts and ensuring reliable contact. The grounding switch contacts adopt a rectangular block structure, reducing closing resistance.

[0037] At the bottom of the mounting base body 24, a polytetrafluoroethylene (PTFE) limiting block 26 is also provided, located below the grounding switch contact finger. The PTFE limiting block 26 is fixed to the bottom surface of the mounting base body 24 by bolts. A limiting groove for the grounding switch contact 22 to extend into is opened on one side of the PTFE limiting block 26. By designing and installing the PTFE limiting block 26 below the grounding switch contact finger, the offset of the contact is limited when subjected to short-circuit electrodynamic forces, avoiding one-sided contact or disengagement.

[0038] The disconnecting switch of the present invention is a one-step grounding switch with a self-locking device. By setting a self-locking device between the base and the grounding rod, it can avoid loosening caused by transmission gap. Under the condition of large short circuit current, it can effectively ensure that the contact fingers of the grounding switch are tightly attached, ensure the reliability of the grounding switch when closing, and improve the performance of the grounding switch product.

[0039] When the grounding switch reaches the closed state, the claw 213 extends and locks with the cam 212 to prevent shaking caused by transmission gap when subjected to short-circuit electric force. When the grounding switch receives the opening signal, the claw 213 retracts and the grounding switch can open normally.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A one-step grounding switch with a self-locking device for an isolating switch, the one-step grounding switch being attached to the isolating switch, the isolating switch comprising a base, insulator posts arranged on the base, and a moving contact and a stationary contact mounted on the insulator posts, and a mounting plate arranged at the top end of the insulator posts for mounting the moving contact and the stationary contact, the one-step grounding switch being mounted on the side of one of the insulator posts, characterized in that: The one-step grounding switch comprises a grounding switch contact, a grounding switch contact finger and a grounding rod; The grounding switch contact finger is installed on the side of the installation plate through the cooperation of a contact finger mounting base; The grounding rod is driven to swing by a driving mechanism installed on the base, and a self-locking device is further arranged between the base and the grounding rod, the self-locking device comprises a cam arranged on the grounding rod and a pawl arranged on the base, the cam is driven to act by the action of the grounding rod, a clamping groove for inserting the pawl is formed on the cam, and the pawl is driven to reciprocate by a linear driver arranged on the base, so as to switch between the unlocking state and the locking state by cooperating with the clamping groove on the cam; The grounding switch contact is installed on one side of the grounding rod and swings under the driving of the grounding rod, so as to approach or move away from the grounding switch contact finger, thereby realizing the opening and closing of the switch.

2. The step-type grounding switch with self-locking device for isolator according to claim 1, characterized in that: A rotating shaft is further connected to the side of the grounding rod away from the grounding switch contact, the two sides of the rotating shaft are installed on the base through the cooperation of bearings and bearing seats, and the rotating shaft is connected to the grounding rod through the cooperation of a fixing assembly; The cam has two, which are arranged on the two sides of the grounding rod respectively, and the two cams are connected to the rotating shaft through the cooperation of a cam sleeve, the cam sleeve is directly sleeved on the outer wall of the rotating shaft, and the cam sleeve is fixedly connected to the rotating shaft through the cooperation of a jacking bolt, and the pawl also has two and corresponds to the two cams.

3. The step-type grounding switch with self-locking device for disconnector according to claim 2, characterized in that: The fixing assembly comprises A fixing plate, a first arc-shaped groove is formed on one side of the fixing plate and is matched with the outer wall of the grounding rod, a second arc-shaped groove is formed on the other side of the fixing plate and is matched with the outer wall of the rotating shaft, and the center line of the first arc-shaped groove is perpendicular to the center line of the second arc-shaped groove; After the outer wall of the grounding rod is matched with the first arc-shaped groove, the outer wall of the rotating shaft is matched with the second arc-shaped groove, and the outer wall of the rotating shaft is fixed through the cooperation of a pair of horizontally distributed connecting blocks, the connecting blocks are located on the two sides of the rotating shaft, a third arc-shaped groove is formed on the side of the connecting block close to the rotating shaft, a plurality of tooth-shaped structures are arranged on the inner wall of the third arc-shaped groove, the two sides of the third arc-shaped groove are fixed to the fixing plate through the cooperation of connecting bolts and nuts, and a through hole is formed on the fixing plate for the connecting bolts to pass through. The cooperation between the grounding switch contact finger and the contact finger mounting base is that the contact finger mounting base comprises a mounting base body, the mounting base body is fixed on the installation plate through the cooperation of a pair of bolts, the mounting base body is in T shape, a contact finger limiting block is installed on one side of the mounting base body, and a limiting groove is formed in the middle of the contact finger limiting block; 4. The step-type grounding switch with self-locking device for isolator according to claim 1, characterized in that: The grounding switch contact finger is composed of a pair of parallel elastic contact finger parts, the elastic contact finger part is in U shape, one side of the elastic contact finger part is fixed on the mounting base body through the cooperation of a bolt, the other side of the elastic contact finger part extends into the limiting groove of the contact finger limiting block, and the two elastic contact finger parts cooperatively form a cavity for inserting the grounding switch contact, and the outer part of the cavity is a V-shaped opening. ​ The grounding switch contact is cuboid, an installation slot for installing the grounding switch contact is opened at the end of the grounding rod, and the grounding switch contact is fixed with the grounding rod through cooperation of bolts.

5. The step-type grounding switch with self-locking device for isolator according to claim 4, characterized in that: The bottom of the installation seat body is further provided with a polytetrafluoroethylene limiting block below the grounding switch contact finger, and a limiting slot for the grounding switch contact to extend into is opened at one side of the polytetrafluoroethylene limiting block.

6. The step-type grounding switch with self-locking device for isolator according to claim 4, characterized in that: The outer side of the elastic contact finger is further provided with a protection plate, and the protection plate is fixed on the installation seat body through cooperation of bolts.

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