Power switching device and its movable contact arrangement

Abstract

This disclosure provides a power switchgear and its moving contact device, the moving contact device comprising: a housing (10); a moving contact (20) slidably mounted within the housing (10) along a sliding axis; a gear and rack mechanism (30) including a gear (31) rotatably mounted within the housing (10) and a rack (32) fixedly disposed on the moving contact (20); and a roller assembly (40) mounted on the housing (10) and located on the side opposite to the gear and rack mechanism (30) with respect to the moving contact (20), including a roller (44) for applying a reverse vertical force to the moving contact (20) to counteract the vertical force perpendicular to the sliding axis formed by the gear and rack mechanism (30) on the moving contact (20). This disclosure can reduce the generation of metal particles to improve the dielectric performance of the power switchgear.

Description

Technical Field

[0001] This disclosure belongs to the technical field of power switchgear, specifically relating to a power switchgear and its moving contact device. Background Technology

[0002] Electrical switchgear includes switch units such as disconnecting switches, grounding switches, or disconnecting-grounding switches, and operating mechanisms for operating these switch units. Each switch unit comprises a stationary contact assembly and a moving contact assembly. The movement of the moving contact in the moving contact assembly engages and disengages with the stationary contact, thereby achieving electrical connection or disconnection.

[0003] For example, current mainstream high-voltage gas-insulated switchgear (GIS) often includes a three-position isolating grounding switch unit with a moving contact device. This unit typically employs a mechanical sliding or rolling contact structure to switch the moving contact between three positions: "isolation closed," "grounding closed," and "disconnect." In a typical existing structure, the moving contact is usually a long rod-shaped conductor, with its two ends corresponding to the isolating stationary contact on the left and the grounding stationary contact on the right, respectively. The moving contact device also includes a rack and pinion mechanism for driving the moving contact. The rack is mounted on the moving contact, and under the drive of the operating mechanism, the gear rotates, causing the rack and moving contact to translate axially along a straight line, achieving the switching between the three states. When the moving contact moves to its leftmost position, its left end is electrically connected to the isolating stationary contact (isolation closed); when the moving contact moves to its rightmost position, its right end is electrically connected to the grounding stationary contact (grounding closed); and in the middle "disconnect" position, neither end of the moving contact is in contact with any stationary contact, achieving complete electrical isolation between the main circuit and the grounding system. To ensure a reliable electrical connection between the stationary and moving contacts, annular contact springs are often provided on the stationary contact and the housing of the moving contact.

[0004] For power switchgear, especially high-voltage switchgear, reliable movement and precise alignment of the moving contacts are the core elements to ensure electrical switching performance and insulation safety.

[0005] In the gear and rack mechanism of the moving contact device, due to the meshing angle of the gear and rack, the contact force between the gear and rack generates a vertical component force perpendicular to the sliding axis of the moving contact. This vertical component force forms a vertical force acting on the moving contact. This vertical force generates a bending moment on the moving contact, causing the moving contact to shift within the moving contact mounting hole of the moving contact device housing. When the shifted moving contact passes through the contact spring at the end of the moving contact mounting hole and the contact spring at the end of the stationary contact under the action of external force, it will experience axial sliding friction with the contact springs, causing a large number of metal particles to fall off the moving contact. This is disastrous for the dielectric performance of the power switchgear. Summary of the Invention

[0006] This disclosure aims to provide a power switchgear and its moving contact device that can reduce the generation of metal particles to improve the dielectric performance of the power switchgear.

[0007] To address the aforementioned technical problems, according to one aspect of this disclosure, a moving contact device for a power switchgear is provided, comprising: a housing; a moving contact slidably mounted within the housing along a sliding axis; a gear and rack mechanism including a gear rotatably mounted within the housing and a rack fixedly disposed on the moving contact, the gear meshing with the rack to drive the moving contact; and further comprising: a roller assembly mounted on the housing and located on the side opposite to the gear and rack mechanism with respect to the moving contact, including a roller for contacting the moving contact during the driving of the moving contact by the gear and rack mechanism to apply a reverse vertical force to the moving contact to counteract the vertical force perpendicular to the sliding axis formed by the gear and rack mechanism on the moving contact.

[0008] By assembling a roller assembly on the opposite side of the moving contact and the gear and rack mechanism, a supporting force equal in magnitude and opposite in direction to the gear meshing force can be applied, achieving mechanical cancellation of the inherent vertical component of the transmission system's force. This design eliminates the positional displacement of the moving contact caused by bending moment during movement, thereby eliminating excessive sliding friction caused by the moving contact's positional displacement and reducing the generation of metal particles. Furthermore, the rolling contact between the roller and the moving contact further reduces metal particle contamination caused by friction compared to sliding contact. Therefore, this invention improves the dielectric performance of power switchgear and ensures safety.

[0009] Further, the roller assembly includes: a bracket mounted on the housing; a roller shaft supported at both ends on the bracket and arranged perpendicular to the moving contact; and the rollers disposed on the roller shaft, including a first roller and a second roller arranged axially along the roller shaft, wherein the first roller and the second roller are both tapered rollers with tapered surfaces, and the small ends of the first roller and the second roller are close to each other, such that the tapered surfaces of the first roller and the second roller are respectively located on both sides of the moving contact to form a V-shaped structure for contacting the moving contact.

[0010] The first and second rollers together form a double-conical V-shaped structure that contacts the moving contact, enabling the moving contact to self-align during sliding. This better eliminates friction between the moving contact and the annular contact spring, reducing the generation of metal particles. Furthermore, the roller assembly can be disassembled and reassembled as a whole using the disassembly bracket, facilitating assembly and maintenance.

[0011] Furthermore, the first roller and the second roller are two independent components spaced apart along the roller shaft; the roller assembly also includes two springs, which are respectively sleeved on the roller shaft and located axially at the outer ends of the first roller and the second roller, so as to press the first roller and the second roller toward each other.

[0012] The first and second rollers form two separate components, each compressed from the outside by two springs, so that the roller assembly forms a V-shaped contact that adapts to the moving contact. This allows the moving contact to better self-align during sliding, thereby reducing the generation of metal particles.

[0013] Furthermore, the roller assembly also includes a spacer sleeve fitted on the roller shaft and positioned axially between the first roller and the second roller to provide a minimum spacing between the first roller and the second roller.

[0014] The minimum spacing provided by the spacer sleeve ensures that when the moving contact is in the separated position (at which point the gear and rack mechanism does not drive the moving contact, and therefore no vertical force is generated), the first and second rollers do not apply force to the moving contact, thereby avoiding fatigue and wear of the moving contact due to force application, and thus better reducing the generation of metal particles.

[0015] Furthermore, the roller assembly also includes bearings respectively disposed at both ends of the roller shaft, and both ends of the roller shaft are respectively mounted on the bracket via the bearings.

[0016] The roller shaft is supported at both ends by bearings. In this way, the roller shaft acts as a rotating axis, and the roller can rotate with the roller shaft without rotating relative to the roller shaft. This avoids the difficulty of roller rotation caused by the contact pressure of the spring on the end of the roller, thus ensuring the working reliability of the roller assembly.

[0017] Furthermore, each of the two ends of the roller shaft includes: a journal for mounting the bearing; and a riveted joint for stopping the bearing mounted on the journal.

[0018] By combining the journal and the rivet joint, an integrated shaft end structure is achieved, eliminating the need for traditional external fasteners, simplifying the structure, and achieving high reliability.

[0019] Furthermore, the roller is formed as an integral piece comprising the first roller and the second roller.

[0020] The rollers are integrated into one piece, which simplifies the structure of the device.

[0021] Furthermore, the housing is provided with a roller assembly mounting recess, and the roller assembly is installed in the roller assembly mounting recess. The moving contact device also includes a roller assembly protective cover, which is installed in the roller assembly mounting recess and surrounds the roller assembly.

[0022] By using the mounting notch and protective cover for the roller assembly, an independent protective environment is created for the roller assembly, protecting its performance from adverse environmental effects and fundamentally ensuring its dielectric reliability during long-term operation.

[0023] Furthermore, the rollers of the roller assembly are made of polyetheretherketone, polyphenylene sulfide, or glass fiber reinforced polyamide.

[0024] By using polyetheretherketone, polyphenylene sulfide, or glass fiber reinforced polyamide as the roller material, the roller has sufficient rigidity and strength, which can better eliminate the positional displacement of the moving contact during movement and better eliminate the generation of metal particles, thereby ensuring dielectric safety.

[0025] According to another aspect of this disclosure, an electrical switchgear is provided, including any of the moving contact devices described above.

[0026] The power switchgear of the present invention can reduce metal particle contamination caused by friction of moving contacts, improve the dielectric performance of the power switchgear, and ensure safety.

[0027] Furthermore, the power switchgear is a high-voltage gas-insulated switchgear, including a three-position isolating grounding switch unit with the moving contact device. The moving contact of the moving contact device has an isolating closed position extending from one end of the housing, a grounding closed position extending from the other end of the housing, and a separated position located between the isolating closed position and the grounding closed position. In the separated position, both ends of the moving contact are located inside the housing, wherein the roller assembly is disposed in the middle of the housing along the sliding axis.

[0028] By centering the roller assembly along the sliding axis of the moving contact in the middle of the housing, the moving contact receives symmetrical, unbiased rolling support throughout its movement in the isolation closed position, grounding closed position, and separation position. This effectively eliminates tilting, jamming, and positioning deviations caused by positional offset of the moving contact, and effectively reduces the generation of metal particles caused by friction of the moving contact, ensuring operational reliability. Attached Figure Description

[0029] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this disclosure, illustrate exemplary embodiments of the present disclosure and are used to explain the disclosure, but do not constitute an undue limitation of the disclosure. In the drawings: Figure 1 This is a three-dimensional structural schematic diagram of a moving contact device for a power switchgear according to an embodiment of the present disclosure.

[0030] Figure 2 yes Figure 1 The diagram shows a three-dimensional longitudinal sectional view of the moving contact device.

[0031] Figure 3 yes Figure 1 The diagram shows a three-dimensional transverse cross-sectional view of the moving contact device.

[0032] Figure 4 yes Figure 1 A schematic diagram of the main structure of the roller assembly in the moving contact device shown.

[0033] Figure 5 yes Figure 4 The diagram shows a three-dimensional longitudinal sectional view of the roller assembly.

[0034] Explanation of icon numbers: Detailed Implementation

[0035] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0036] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise.

[0037] Figure 1 This is a three-dimensional structural schematic diagram of a moving contact device for a power switchgear according to an embodiment of the present disclosure. Figure 2 yes Figure 1 The diagram shows a three-dimensional longitudinal sectional view of the moving contact device. Figure 3 yes Figure 1 The diagram shows a three-dimensional transverse cross-sectional view of the moving contact device.

[0038] See Figures 1 to 3As can be seen, the moving contact device for power switchgear disclosed herein includes: a housing 10, the housing 10 having a moving contact mounting hole 11 and a gear mounting hole 13 perpendicular to the moving contact mounting hole. Annular contact spring mounting grooves 12 are formed at both ends of the moving contact mounting hole 11 for mounting annular contact springs.

[0039] A movable contact 20 is provided inside the housing 10, and the movable contact is slidably mounted in the movable contact mounting hole 11 of the housing 10 along a sliding axis. A gear and rack mechanism 30 is also provided inside the housing 10, which includes a gear 21 and a rack 32. The gear 21 is rotatably mounted in the gear mounting hole 13 of the housing 10, and the rack 32 is fixedly mounted on the movable contact 20. The gear 31 meshes with the rack 32 to drive the movable contact 20, such that the movable contact 20 has a closed position extending out of the housing 10 for engagement with the stationary contact of the power switchgear, and a retracted position within the housing 10.

[0040] from Figures 1 to 3 It can also be seen that the moving contact device further includes a roller assembly 40, which is mounted on the housing 10 and located on the side opposite to the gear and rack mechanism 30 with respect to the moving contact 20. The roller assembly 40 includes a roller 44, which is used to contact the moving contact 20 during the driving of the moving contact 20 by the gear and rack mechanism 30, so as to apply a reverse vertical force to the moving contact 20 to counteract the vertical force perpendicular to the sliding axis formed by the gear and rack mechanism 30 on the moving contact 20.

[0041] By assembling a roller assembly on the opposite side of the moving contact and the gear and rack mechanism, a supporting force equal in magnitude and opposite in direction to the gear meshing force can be applied, achieving mechanical cancellation of the inherent vertical component of the transmission system's force. This moving contact device eliminates positional displacement of the moving contact caused by bending moment during movement, thereby eliminating excessive sliding friction caused by moving contact positional displacement and reducing the generation of metal particles. Furthermore, the rolling contact formed between the roller and the moving contact further reduces metal particle contamination caused by friction compared to sliding contact. Therefore, this invention improves the dielectric performance of power switchgear and ensures safety.

[0042] Figure 4 yes Figure 1 A schematic diagram of the main structure of the roller assembly in the moving contact device shown. Figure 5 yes Figure 4 The diagram shows a three-dimensional longitudinal sectional view of the roller assembly.

[0043] See also Figure 3 , Figure 4 and Figure 5As can be seen, the roller assembly 40 includes: a bracket 41, mounted on the housing 10; a roller shaft 42, with both ends supported on the bracket 41 and arranged perpendicular to the moving contact 20; and a roller 44, disposed on the roller shaft 42.

[0044] Preferably, the roller 44 includes a first roller 44a and a second roller 44b arranged axially along the roller shaft 42. Both the first roller 44a and the second roller 44b are tapered rollers with tapered surfaces 441, and the small ends of the first roller 44a and the second roller 44b are close to each other, such that the tapered surfaces 441 of the first roller 44a and the second roller 44b are located on both sides of the moving contact 20 to form a V-shaped structure for contacting the moving contact 20.

[0045] The first roller 44a and the second roller 44b together form a double-conical V-shaped structure that contacts the moving contact. This allows the moving contact to self-align during sliding, thereby better eliminating friction between the moving contact and the annular contact spring and reducing the generation of metal particles. Furthermore, the roller assembly can be disassembled and reassembled as a whole using the disassembly bracket, facilitating assembly and maintenance.

[0046] It is understandable that roller 44 can also be other types of rollers, such as cylindrical rollers, which can also apply a reverse vertical force to the moving contact.

[0047] See also Figure 3 , Figure 4 and Figure 5 As can be seen, the first roller 44a and the second roller 44b are two independent components spaced apart along the roller shaft 42. The roller assembly 40 also includes two springs 43, which are respectively sleeved on the roller shaft 42 and located axially at the outer ends of the first roller 44a and the second roller 44b, so as to press the first roller 44a and the second roller 44b toward each other.

[0048] The first and second rollers form two separate components, each compressed from the outside by two springs, so that the roller assembly forms a V-shaped contact that adapts to the moving contact. This allows the moving contact to better self-align during sliding, thereby reducing the generation of metal particles.

[0049] In an embodiment not shown, the roller 44 may also be formed as a single piece comprising a first roller 44a and a second roller 44b. Forming the rollers as a single piece simplifies the structure of the device.

[0050] See Figure 5 It can also be seen that the roller assembly 40 further includes a spacer sleeve 45, which is sleeved on the roller shaft 42 and located axially between the first roller 44a and the second roller 44b to provide the minimum spacing between the first roller 44a and the second roller 44b.

[0051] The minimum spacing provided by the spacer sleeve ensures that when the moving contact 20 is in the disengaged position (where the rack and pinion mechanism does not drive the moving contact and therefore no vertical force is generated), the first roller 44a and the second roller 44b do not exert force on the moving contact, thereby avoiding fatigue and wear of the moving contact due to force application, and thus better reducing the generation of metal particles. The minimum spacing can be achieved by configuring the length of the spacer sleeve. Simultaneously, the spring ensures that when the moving contact shifts position due to the vertical force, causing the first and second rollers to move away from each other, it adaptively applies an axial force to the first and second rollers, thereby applying a reverse vertical force to the moving contact through the first and second rollers.

[0052] In one embodiment, the spacer sleeve may be integrally formed with the first or second roller. In the preferred embodiment shown, the spacer sleeve is a separate component independent of the first and second rollers.

[0053] See also Figure 5 As can be seen, the roller assembly 40 also includes bearings 46 respectively disposed at both ends of the roller shaft 42, and both ends of the roller shaft 42 are respectively mounted on the bracket 41 through the bearings 46.

[0054] The roller shaft is supported at both ends by bearings. In this way, the roller shaft acts as a rotating axis, and the roller can rotate with the roller shaft without rotating relative to the roller shaft. This avoids the difficulty of roller rotation caused by the contact pressure of the spring on the end of the roller, thus ensuring the working reliability of the roller assembly.

[0055] See still Figure 5 As can be seen, each of the two ends of the roller shaft 42 includes a journal 421 and a riveted joint 422. The journal 421 is used to mount the bearing 46, and the riveted joint 422 is used to stop the bearing 46 mounted on the journal 421. The bearing 46 can be a rolling bearing or a sliding bearing.

[0056] By combining the journal and the rivet joint, an integrated shaft end structure is achieved, eliminating the need for traditional external fasteners, simplifying the structure, and achieving high reliability.

[0057] Back to Figures 1 to 3 As can be seen, the housing 10 is provided with a roller assembly mounting recess 14, and the roller assembly 40 is installed in the roller assembly mounting recess 14. The moving contact device also includes: a roller assembly protective cover 50, which is installed in the roller assembly mounting recess 14 and surrounds the roller assembly 40.

[0058] By using the mounting notch and protective cover for the roller assembly, an independent protective environment is created for the roller assembly, protecting its performance from adverse environmental effects and fundamentally ensuring its dielectric reliability during long-term operation.

[0059] According to embodiments of the present disclosure, the roller 44 of the roller assembly 40 may be made of polyetheretherketone (PEEK), polyphenylene sulfide (PSS), or glass fiber reinforced polyamide (such as PA66-GF30 or PA46-GF50).

[0060] By using PEEK, PPS, or glass fiber reinforced polyamide as the roller material, the roller has sufficient rigidity and strength, which can better eliminate the positional displacement of the moving contact during movement and better eliminate the generation of metal particles, thereby ensuring dielectric safety.

[0061] According to another aspect of this disclosure, an electrical switching device is also provided, including any of the aforementioned moving contact devices.

[0062] The power switchgear of the present invention can reduce metal particle contamination caused by friction of moving contacts, improve the dielectric performance of the power switchgear, and ensure safety.

[0063] According to one embodiment of this disclosure, the power switchgear is a high-voltage gas-insulated switchgear, including a three-position isolating grounding switch unit with a moving contact device. See also... Figure 2 The moving contact 20 of the moving contact device has an isolated closed position extending from one end of the housing 10, a grounded closed position extending from the other end of the housing 10, and a separated position located between the isolated closed position and the grounded closed position. In the separated position, both ends of the moving contact 20 are located inside the housing 10. The roller assembly 40 is arranged in the middle of the housing 10 along the sliding axis.

[0064] By centering the roller assembly 40 along the sliding axis of the moving contact 20 in the middle of the housing 10, the moving contact receives symmetrical and unbiased rolling support throughout its movement in the isolation closed position, grounding closed position, and separation position. This effectively eliminates tilting, jamming, and positioning deviations caused by positional offset of the moving contact, effectively reduces the generation of metal particles caused by friction of the moving contact, and ensures operational reliability.

[0065] The above are merely preferred embodiments of this disclosure. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this disclosure, and these improvements and modifications should also be considered within the scope of protection of this disclosure.

Claims

1. A moving contact device for a power switchgear, comprising: Shell (10); The moving contact (20) is slidably mounted inside the housing (10) along the sliding axis; The gear and rack mechanism (30) includes a gear (31) rotatably mounted in the housing (10) and a rack (32) fixedly disposed on the moving contact (20), wherein the gear (31) meshes with the rack (32) to drive the moving contact (20). Its characteristic is that it further includes: A roller assembly (40), mounted on the housing (10), is located on the side opposite to the gear and rack mechanism (30) with respect to the moving contact (20), and includes a roller (44) for contacting the moving contact (20) during the process of the gear and rack mechanism (30) driving the moving contact (20) to apply a reverse vertical force to the moving contact (20) to counteract the vertical force perpendicular to the sliding axis formed by the gear and rack mechanism (30) on the moving contact (20).

2. The moving contact device according to claim 1, characterized in that, The roller assembly (40) includes: A bracket (41) is mounted on the housing (10); The roller shaft (42) is supported at both ends on the bracket (41) and arranged perpendicular to the moving contact (20); and The roller (44) is disposed on the roller shaft (42) and includes a first roller (44a) and a second roller (44b) arranged axially along the roller shaft (42). The first roller (44a) and the second roller (44b) are both tapered rollers with tapered surfaces (441), and the small ends of the first roller (44a) and the second roller (44b) are close to each other, such that the tapered surfaces (441) of the first roller (44a) and the second roller (44b) are respectively located on both sides of the moving contact (20) to form a V-shaped structure for contacting the moving contact (20).

3. The moving contact device according to claim 2, characterized in that, The first roller (44a) and the second roller (44b) are two independent components spaced apart along the roller shaft (42); The roller assembly (40) also includes two springs (43), which are respectively sleeved on the roller shaft (42) and located axially at the outer ends of the first roller (44a) and the second roller (44b) to press the first roller (44a) and the second roller (44b) toward each other.

4. The moving contact device according to claim 3, characterized in that, The roller assembly (40) further includes a spacer sleeve (45) sleeved on the roller shaft (42) and positioned axially between the first roller (44a) and the second roller (44b) to provide a minimum spacing between the first roller (44a) and the second roller (44b).

5. The moving contact device according to claim 2, characterized in that, The roller assembly (40) also includes bearings (46) respectively disposed at both ends of the roller shaft (42), and both ends of the roller shaft (42) are respectively mounted on the bracket (41) through the bearings (46).

6. The moving contact device according to claim 5, characterized in that, Each of the two ends of the roller shaft (42) includes: Journal (421) for mounting the bearing (46); and The riveted joint (422) is used to stop the bearing (46) mounted on the journal (421).

7. The moving contact device according to claim 2, characterized in that, The roller (44) is formed as an integral piece including the first roller (44a) and the second roller (44b).

8. The moving contact device according to any one of claims 1 to 7, characterized in that, The housing (10) is provided with a roller assembly mounting recess (14), and the roller assembly (40) is installed in the roller assembly mounting recess (14). The moving contact device also includes: A roller assembly protective cover (50) is installed in the roller assembly mounting recess (14) and surrounds the roller assembly (40).

9. The moving contact device according to any one of claims 1 to 7, characterized in that, The rollers (44) of the roller assembly (40) are made of polyetheretherketone (PEEK), polyphenylene sulfide (PSS), or glass fiber reinforced polyamide (such as PA66-GF30 or PA46-GF50).

10. A power switchgear, characterized in that, The moving contact device includes any one of claims 1 to 9.

11. The power switchgear according to claim 10, characterized in that, The power switchgear is a high-voltage gas-insulated switchgear, including a three-position isolating grounding switch unit with the moving contact device. The moving contact (20) of the moving contact device has an isolating closed position extending from one end of the housing (10), a grounding closed position extending from the other end of the housing (10), and a separated position located between the isolating closed position and the grounding closed position. In the separated position, both ends of the moving contact (20) are located inside the housing (10). The roller assembly (40) is disposed in the middle of the housing (10) along the sliding axis.

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