Transmission structure of vacuum circuit breaker

Abstract

The invention relates to and discloses a vacuum circuit breaker transmission structure, which belongs to the technical field of vacuum circuit breakers, and comprises a vacuum arc extinguish chamber moving contact, a moving support and a piston rod, the top of the moving support is provided with a moving contact seat, the bottom of the moving support is provided with a guide seat, the guide seat extends into the moving support, and a buffer cylinder is slidably connected in the guide seat. One end of the piston rod is installed on the buffer cylinder through an end cover, the other end of the piston rod is provided with a nut, the piston rod between the nut and the end cover is provided with a contact spring, oil is contained in the buffer cylinder, the side face of the lower portion of the buffer cylinder is provided with an oil valve, and a vacuum arc-extinguishing chamber moving contact is connected with a moving contact base in a sliding mode and fixed to the piston rod. According to the device, through linkage of the piston rod, the end cover, the buffer cylinder and the oil valve, the switching-on bounce time is shortened, the action consistency between the moving contact of the vacuum circuit breaker and the operating mechanism is kept, and the problem that the service life of key parts of the vacuum circuit breaker is affected due to switching-off overshoot is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of vacuum circuit breakers, and particularly to a transmission structure of a vacuum circuit breaker. Background Art

[0002] A vacuum circuit breaker gets its name because both the arc extinguishing medium and the insulating medium in the contact gap after arc extinguishing are high vacuum; it has the advantages of small volume, light weight, being suitable for frequent operation, and no need for maintenance of arc extinguishing, and is widely used in the distribution network. With the increase of voltage level, the size and mass of the moving contact of the vacuum interrupter have been greatly improved, and its kinetic energy during movement is also increasing. During closing, the moving contact collides with the static contact at a certain speed. According to the law of conservation of momentum, the moving contact rebounds and compresses the contact spring, and the compressed contact spring gives the moving contact a force towards the static contact to make the moving contact hit the static contact again. This process will be repeated until the energy is consumed. The greater the kinetic energy, the more collision times.

[0003] The process of repeated bouncing of the moving contact during closing of the vacuum circuit breaker is called closing bounce. The longer the closing bounce time, the longer the pre-breakdown time during closing will be, and then the ablation time will also become longer. The surface quality of the contact will decline due to long-term ablation, and then the breaking capacity and electrical life of the vacuum interrupter will decrease. During opening, since the contact spring connected between the moving contact and the operating mechanism is a soft connection, when the mechanism decelerates and stops, the moving contact will continue to compress the contact spring under the action of kinetic energy, resulting in inconsistent actions between the moving contact and the operating mechanism, leading to a relatively serious overshoot, damaging the bellows of the vacuum interrupter, and then affecting the service life of the key components and the whole of the vacuum interrupter. Summary of the Invention

[0004] In order to overcome the defect that the overshoot during opening affects the service life of the key components of the vacuum circuit breaker in the prior art, the present invention provides a transmission structure of a vacuum circuit breaker to shorten the closing bounce time and maintain the consistency of the actions between the moving contact of the vacuum circuit breaker and the operating mechanism. The technical solution adopted by the present invention to solve its technical problems is: a transmission structure of a vacuum circuit breaker, including a moving contact of the vacuum interrupter, a moving support, and a piston rod. A moving contact seat is installed at the top of the moving support, a guiding seat is installed at the bottom of the moving support, the guiding seat extends into the interior of the moving support, a buffer cylinder is slidably connected in the guiding seat, one end of the piston rod is installed on the buffer cylinder through an end cover, a nut is installed at the other end of the piston rod, a contact spring is arranged on the piston rod between the nut and the end cover, the buffer cylinder is filled with hydraulic oil, an oil valve is arranged on the lower side of the buffer cylinder, and the moving contact of the vacuum interrupter is slidably connected to the moving contact seat and fixed to the piston rod.

[0005] As a further improvement of the present invention, the end cover is of an inverted frustum structure.

[0006] As a further improvement of the present invention, a dust-proof ring and a special seal are successively provided in the inner cavity of the end cover from top to bottom. A first sealing ring is provided on the outer wall of the end cover. A first threaded hole is provided at the top of the end cover, and a buffer hole is provided on the side of the bottom of the end cover.

[0007] As a further improvement of the present invention, a guide ring is provided on the outer wall of the buffer cylinder. As a further improvement of the present invention, a first oil cavity, a second oil cavity and a third oil cavity are provided inside the buffer cylinder. The first oil cavity is communicated with the third oil cavity through an oil passage, and an oil valve is installed on the oil passage.

[0008] As a further improvement of the present invention, vent holes are provided on the sides of the guide seat and the moving support to maintain air pressure balance.

[0009] As a further improvement of the present invention, the upper end of the piston rod is provided with a thread and is in threaded fit with the moving contact of the vacuum interrupter.

[0010] As a further improvement of the present invention, the compression amount of the contact spring can be adjusted by a nut.

[0011] Compared with the prior art, the present invention has the following beneficial effects: Through the linkage of the piston rod, the end cover, the buffer cylinder and the oil valve, the closing bounce time is shortened, the consistency of the actions between the moving contact of the vacuum circuit breaker and the operating mechanism is maintained, and the problem that the life of the key components of the vacuum circuit breaker is affected by overshoot during opening is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention will be further described below in conjunction with the drawings and specific embodiments.

[0013] Figure 1 FIG. is a schematic structural diagram of a transmission structure of a vacuum circuit breaker according to the present invention.

[0014] Figure 2 FIG. is a schematic structural diagram of the end cover of the present invention.

[0015] Figure 3 FIG. is a schematic structural diagram of the oil cylinder of the present invention.

[0016] In the figure: 1. Moving contact of vacuum interrupter; 2. Moving contact seat; 3. Moving support; 4. Guide seat; 5. Nut; 6. Piston rod; 7. Contact spring; 8. End cover; 801. Dust-proof ring; 802. Special seal; 803. Buffer hole; 804. Threaded hole; 805. First sealing ring; 9. Guide ring; 10. Buffer cylinder; 1001. First oil cavity; 1002. Second oil cavity; 1003. Third oil cavity; 1004. Oil passage; 11. Oil valve; 12. Oil; 13. Vent hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] For the technical solutions and beneficial effects of the present invention to be more clearly understood, the present invention will be further described in detail below with reference to specific embodiments.

[0018] Referring to Figure 1 , an embodiment of the present invention discloses a transmission structure of a vacuum circuit breaker, which includes a moving contact 1 of a vacuum interrupter, a moving support 3 and a piston rod 6. A moving contact holder 2 is installed at the top of the moving support 3, and a guide seat 4 is installed at the bottom of the moving support 3. The guide seat 4 extends into the interior of the moving support 3. A buffer cylinder 10 is slidably connected in the guide seat 4. One end of the piston rod 6 is installed on the buffer cylinder 10 through an end cover 8, and a nut 5 is installed at the other end of the piston rod 6. A contact spring 7 is provided on the piston rod 6 between the nut 5 and the end cover 8. The buffer cylinder 10 is filled with a hydraulic fluid 12, and an oil valve 11 is provided on the lower side of the buffer cylinder 10. The moving contact 1 of the vacuum interrupter is slidably connected to the moving contact holder 2 and fixed to the piston rod 6.

[0019] Referring to Figure 2 , the end cover 8 is of an inverted frustum structure. An anti-dust ring 801 and two O-rings 802 are successively provided in the inner cavity of the end cover 8 from top to bottom. The anti-dust ring 801 and the O-rings 802 cooperate with the piston rod 6. A buffer hole 803 is provided on the bottom side of the end cover 8, and two first threaded holes 804 are provided on the top of the end cover 8. A first sealing ring 805 is provided on the outer wall of the end cover 8, and the first sealing ring 805 cooperates with the buffer cylinder 10.

[0020] The number and size of the buffer holes 803 are adjusted according to the opening characteristics; the first threaded holes 804 are tooling holes for tightening the end cover 8 and the buffer cylinder 10.

[0021] Referring to Figure 3 , a guide ring 9 is installed outside the buffer cylinder 10. Two platforms are symmetrically distributed at the lower part of the buffer cylinder 10 for installing the oil valve 11. A first oil chamber 1001 is formed between the inside of the buffer cylinder 10 and the outside of the end cover 8, a second oil chamber 1002 is formed between the piston rod 6 and the inside of the end cover 8, and a third oil chamber 1003 is formed between the bottom of the piston rod 6 and the center of the inside of the buffer cylinder 10. The first oil chamber 1001 is connected to the third oil chamber 1003 through an oil passage 1004, and the oil valve 11 is installed on the oil passage 1004. The on-off of the oil passage 1004 is controlled by the oil valve 11.

[0022] Vent holes 13 are provided on the sides of the guide seat 4 and the moving support 3 to maintain air pressure balance. There is a slope at the middle position inside the guide seat 4, with an angle of 20 - 30°; the upper end of the piston rod 6 is provided with a thread and is in threaded cooperation with the moving contact 1 of the vacuum interrupter; the compression amount of the contact spring 7 can be adjusted by the nut 5.

[0023] In a certain embodiment of the present invention, the stroke of the moving contact 1 of the vacuum interrupter is 100 mm, and the compression stroke of the contact spring 7 is 20 mm.

[0024] Process from opening to closing: In the initial state, under the action of the oil valve 11, the oil passage 1004 is in a closed state. When the moving contact 1 of the vacuum interrupter moves from the start of its stroke to 80 mm, the oil valve 11 controls the opening of the oil passage 1004, and the third oil chamber 1003 communicates with the first oil chamber 1001. When the closing stroke of the moving contact 1 of the vacuum interrupter reaches 80 mm, at this time, the moving contact 1 of the vacuum interrupter collides with the static contact of the interrupter, and the moving contact 1 of the vacuum interrupter rebounds under force. Due to the damping effect of the oil in the third oil chamber 1003, most of the energy is consumed, resulting in a significant reduction in the rebound displacement. When the moving contact 1 of the vacuum interrupter moves from 80 mm to 100 mm in stroke, the moving contact 1 of the vacuum interrupter and the piston rod 6 connected thereto no longer move, and the buffer cylinder 10 continues to move upward. The volume of the third oil chamber 1003 becomes smaller, and the oil flows through the oil passage 1004 to the first oil chamber 1001, and the volume of the second oil chamber 1002 becomes larger. When the stroke of the moving contact 1 of the vacuum interrupter reaches 100 mm, it is the closing position.

[0025] Process from closing to opening: During the process of the moving contact 1 of the vacuum interrupter moving from the closing position to a 20-mm opening stroke, the buffer cylinder 10 moves downward, the volume of the second oil chamber 1002 becomes smaller, and the oil is pressed through the buffer hole 803 and flows to the first oil chamber 1001. The opening characteristics can be controlled by controlling the number and size of the buffer holes 803. When the opening stroke of the moving contact 1 of the vacuum interrupter reaches 20 mm. During the process of the moving contact 1 of the vacuum interrupter moving from a 20-mm opening stroke to the opening position of 100-mm opening stroke, the oil valve 11 controls the closing of the oil passage 1004, and the third oil chamber 1003 cannot flow. When the mechanism decelerates or stops, since the oil in the third oil chamber 1003 cannot flow out, the relative movement between the piston rod 6 and the buffer cylinder 10 is inhibited, the contact spring 7 cannot be compressed, and the entire transmission component has no relative movement and decelerates and stops together with the mechanism. This device maintains the consistency of the actions between the moving contact 1 of the vacuum interrupter and the operating mechanism, and solves the problem of the impact of opening overshoot on the service life of the key components of the vacuum circuit breaker.

[0026] It should be understood that the specific embodiments described herein are only for understanding the present invention and are not used to limit the present invention. All other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present invention.

Claims

1. A vacuum circuit breaker transmission structure, characterized in that: The invention comprises a vacuum interrupter moving contact (1), a moving support (3) and a piston rod (6); a moving contact seat (2) is mounted on the top of the moving support (3); a guide seat (4) is mounted on the bottom of the moving support (3); the guide seat (4) extends into the interior of the moving support (3); a buffer cylinder (10) is slidably connected to the guide seat (4); one end of the piston rod (6) is mounted on the buffer cylinder (10) via an end cover (8); a nut (5) is mounted on the other end of the piston rod (6); a contact spring (7) is provided on the piston rod (6) between the nut (5) and the end cover (8); oil (12) is contained in the buffer cylinder (10); an oil valve (11) is provided on the lower side of the buffer cylinder (10); the vacuum interrupter moving contact (1) is slidably connected to the moving contact seat (2) and is fixed to the piston rod (6).

2. A vacuum circuit breaker transmission structure according to claim 1, characterized in that: The end cover (8) is an inverted frustum structure.

3. A vacuum circuit breaker transmission structure according to claim 2, characterized in that: The inner cavity of the end cover (8) is provided with a dustproof ring (801) and a Sterling seal (802) in order from top to bottom, a first sealing ring (805) is provided on the outer wall of the end cover (8), a first threaded hole (804) is provided on the top of the end cover (8), and a buffer hole (803) is provided on the bottom side of the end cover (8).

4. A vacuum circuit breaker transmission structure according to claim 1, characterized in that: A guide ring (9) is provided on the outer wall of the buffer cylinder (10).

5. A vacuum circuit breaker transmission structure according to claim 4, characterized in that: A first oil chamber (1001), a second oil chamber (1002) and a third oil chamber (1003) are provided inside the buffer cylinder (10); the first oil chamber (1001) and the third oil chamber (1003) are connected via an oil passage (1004); and the oil valve (11) is mounted on the oil passage (1004).

6. A vacuum circuit breaker transmission structure according to claim 1, characterized in that: Ventilation holes (13) are provided on the sides of the guide seat (4) and the movable support seat (3) to maintain air pressure balance.

7. A vacuum circuit breaker transmission structure according to claim 6, characterized in that: The upper end of the piston rod 6 is provided with a thread, and is matched with the thread of the moving contact (1) of the vacuum interrupter.

8. A vacuum circuit breaker transmission structure according to claim 7, characterized in that: The compression amount of the contact spring (7) can be adjusted by the nut (5).

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