A vacuum interrupter

Abstract

This utility model discloses a vacuum interrupter, including a shell. An end cap is fixedly connected to the top of the shell, and a moving contact assembly is movably connected to the surface of the end cap. A stationary contact assembly is installed at the bottom of the shell, opposite to the moving contact assembly, and the stationary contact assembly is in movable contact with the moving contact assembly. A shielding cylinder is installed on the inner wall of the shell at the position opposite to the movable contact connection of the stationary contact assembly and the moving contact assembly. The shielding cylinder includes a first connecting cylinder, a second connecting cylinder, and a shielding block. The shielding block is fixedly connected between the first connecting cylinder and the second connecting cylinder. Creepage grooves are uniformly formed on the inner wall surface of the shielding block. This utility model, through an innovative composite shielding cylinder structure with creepage grooves, effectively solves the problem of poor shielding effect under high current leading to insulation degradation of the inner wall of the shell in the prior art. It effectively improves the electrical insulation strength, anti-pollution ability, and breaking reliability of the vacuum interrupter, and has the advantages of practical structure and significant effect.

Description

Technical Field

[0001] This utility model relates to the field of vacuum interrupter technology, specifically a vacuum interrupter. Background Technology

[0002] The vacuum interrupter is the core component of a vacuum circuit breaker. Applying a longitudinal magnetic field to the contact gap can effectively control the shape of the vacuum arc and improve the short-circuit current breaking capacity. There are various ways to generate the longitudinal magnetic field; a widely used method is through the design of a cup-shaped contact structure. When current flows through the inclined slots in the contact cup, a longitudinal magnetic field is generated in the contact gap.

[0003] However, existing vacuum interrupters simply have a single shield inside to prevent the contacts from generating a large amount of metal vapor and liquid droplets during the arcing process. However, the simple shield is not very effective under high current switching conditions, and therefore cannot better protect the inner wall of the casing. This can lead to a decrease in the insulation strength of the casing or the occurrence of flashover. Summary of the Invention

[0004] The purpose of this invention is to provide a vacuum interrupter to solve the problem mentioned in the background art, where the existing vacuum interrupter simply has a shielding cover inside to prevent the contacts from generating a large amount of metal vapor and liquid droplet splashing during the arcing process. However, the simple shielding cover is not very effective under the switching of large currents, and thus cannot better protect the inner wall of the shell, which will cause the insulation strength of the shell to decrease or flashover to occur.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a vacuum interrupter, comprising a shell, an end cap fixedly connected to the top of the shell, a moving contact assembly movably connected to the surface of the end cap, a stationary contact assembly installed at the bottom of the shell at a position opposite to the moving contact assembly, and the stationary contact assembly and the moving contact assembly in movable contact, a shielding cylinder installed on the inner wall of the shell at a position opposite to the movable contact connection of the stationary contact assembly and the moving contact assembly, the shielding cylinder comprising a connecting cylinder one, a connecting cylinder two, and a shielding block, the shielding block being fixedly connected between the connecting cylinder one and the connecting cylinder two, and creepage grooves uniformly formed on the inner wall surface of the shielding block.

[0006] Preferably, the moving contact assembly includes a moving conductive rod, a moving contact, and a bellows. The moving conductive rod is movably connected inside the end cap, and the moving contact is fixedly connected to the bottom of the moving conductive rod. The bellows is sleeved on the surface of the moving conductive rod at the upper end of the moving contact.

[0007] Preferably, the stationary contact assembly includes a stationary conductive rod and a stationary contact. The stationary conductive rod is fixedly connected to the bottom of the inner wall of the housing, and the stationary contact is fixedly connected to the top of the stationary conductive rod, with the surface of the stationary contact in movable contact with the surface of the moving contact.

[0008] Preferably, both the stationary contact and the moving contact have through grooves on their surfaces, and the through grooves are arranged in a ring shape.

[0009] Preferably, the depth of the plurality of creepage grooves increases layer by layer from bottom to top.

[0010] Beneficial effects

[0011] Compared with existing technologies, the beneficial effects of this utility model are as follows:

[0012] This utility model, through an innovative composite shielding cylinder structure with creepage grooves, effectively solves the problem of poor shielding effect under high current leading to insulation degradation of the inner wall of the outer shell in the prior art. It effectively improves the electrical insulation strength, anti-pollution ability and breaking reliability of the vacuum interrupter, and has the advantages of practical structure and significant effect. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0014] Figure 2 This is a schematic diagram of the overall cross-sectional structure of this utility model;

[0015] Figure 3 This is a schematic diagram of the mating structure of the moving contact and the stationary contact of this utility model.

[0016] The correspondence between the labels and component names in the attached figures is as follows:

[0017] 1. Housing; 2. End cap; 3. Moving contact assembly; 4. Shielding cylinder; 5. Stationary contact assembly; 6. Moving conductive rod;

[0018] 32. Moving contact; 33. Bellows; 41. Connecting cylinder one; 42. Connecting cylinder two; 43. Shielding block;

[0019] 44. Climbing groove; 51. Static conductive rod; 52. Static contact; 53. Through groove. Detailed Implementation

[0020] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0021] In the description of this utility model, it should be noted that the terms "upper," "lower," "left," "right," "front," "rear," "inner," "outer," "vertical," and "horizontal," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] like Figure 1-3 This is a schematic diagram of a vacuum interrupter according to a preferred embodiment of the present invention. In this embodiment, the vacuum interrupter includes a cylindrical ceramic shell 1, and a metal end cap 2 is fixedly connected to the top of the shell 1 by vacuum brazing. The end cap 2 has a guide hole in its center, and the moving conductive rod 31 of the moving contact assembly 3 passes through the guide hole and is clearance-fitted with it to achieve axial movable connection. A moving contact 32 made of copper-chromium alloy is welded to the bottom of the moving conductive rod 31, and a stainless steel bellows 33 is sleeved on the surface of the moving conductive rod 31. The upper end of the bellows 33 is welded to the inner wall of the end cap 2, and the lower end is welded to the moving conductive rod 31 to form a dynamic vacuum seal.

[0023] In this embodiment, the stationary contact assembly 5 is fixedly installed at the bottom of the housing 1 by bolts. The stationary conductive rod 51 is vertically fixed at the center of the bottom of the housing, and a stationary contact 52 coaxially opposite to the moving contact 32 is welded to its top. The contact surfaces of the stationary contact 52 and the moving contact 32 are both machined with eight annular through grooves 53. The through grooves 53 are distributed in concentric circles and have a depth of 1.5 mm, which are used to disperse the electric arc.

[0024] In this embodiment, a stepped shielding cylinder 4 is installed on the inner wall of the housing 1, around the contact area of ​​the contactor. The shielding cylinder 4 is made of oxygen-free copper and includes an upper connecting cylinder 41, a lower connecting cylinder 42, and an annular shielding block 43 between them. The inner wall of the shielding block 43 is machined with multiple vertical creepage grooves 44, with the groove depth increasing gradually from bottom to top. The lowest groove 44 is 1 mm deep, increasing progressively upwards, with the uppermost groove reaching a depth of 3.2 mm. This design elongates the path of the electric arc as it creeps along the inner wall of the shielding cylinder 4, accelerating arc cooling and dielectric recovery.

[0025] Work process:

[0026] When the circuit is closed, the moving contact 32 moves down to contact the stationary contact 52 and conducts current; when the circuit is opened, the moving contact 32 moves up to generate an electric arc, which, driven by the magnetic field, spreads outward along the annular groove 53 to the shielding cylinder 4. After the electric arc enters the creepage groove 44, it is forced to bend multiple times due to the change in groove depth gradient, and the metal vapor is adsorbed in the deep groove area, effectively suppressing reignition.

[0027] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present utility model. It should not be construed that the specific implementation of the present utility model is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present utility model, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted by the present utility model.

Claims

1. A vacuum interrupter, comprising a shell (1), characterized in that: The top of the housing (1) is fixedly connected to an end cap (2), and a moving contact assembly (3) is movably connected to the surface of the end cap (2). A stationary contact assembly (5) is installed at the bottom of the housing (1) at a position opposite to the moving contact assembly (3), and the stationary contact assembly (5) is in contact with the moving contact assembly (3). A shielding cylinder (4) is installed on the inner wall of the housing (1) at a position opposite to the position where the stationary contact assembly (5) and the moving contact assembly (3) are in contact. The shielding cylinder (4) includes a connecting cylinder one (41), a connecting cylinder two (42), and a shielding block (43). The shielding block (43) is fixedly connected between the connecting cylinder one (41) and the connecting cylinder two (42). A plurality of creepage grooves (44) are evenly opened on the inner wall surface of the shielding block (43).

2. The vacuum interrupter according to claim 1, characterized in that: The moving contact assembly (3) includes a moving conductive rod (31), a moving contact (32), and a bellows (33). The moving conductive rod (31) is movably connected inside the end cap (2). The moving contact (32) is fixedly connected to the bottom of the moving conductive rod (31). The bellows (33) is sleeved on the surface of the moving conductive rod (31) above the moving contact (32).

3. The vacuum interrupter according to claim 1, characterized in that: The stationary contact assembly (5) includes a stationary conductive rod (51) and a stationary contact (52). The stationary conductive rod (51) is fixedly connected to the bottom of the inner wall of the housing (1). The stationary contact (52) is fixedly connected to the top of the stationary conductive rod (51), and the surface of the stationary contact (52) is in active contact with the surface of the moving contact (32).

4. The vacuum interrupter according to claim 3, characterized in that: Both the stationary contact (52) and the moving contact (32) have through grooves (53) on their surfaces, and the through grooves (53) are designed in a ring shape.

5. The vacuum interrupter according to claim 1, characterized in that: The depth of the multiple creepage grooves (44) increases from bottom to top.

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