Ring main unit for isolating circuit breaker switch under environment-friendly gas insulation

Abstract

The invention discloses a ring main unit of an environment-friendly gas insulation lower isolation circuit breaker switch. The ring main unit comprises a gas box, a circuit breaker mechanism, an isolation mechanism and a lower isolation circuit breaker switch. An expansion sleeve and an incoming and outgoing line sleeve are arranged in the gas tank; the circuit breaker mechanism and the isolation mechanism are mounted on the gas tank; the lower isolation circuit breaker switch is arranged in the air box; the lower isolation circuit breaker switch comprises a circuit breaker switch and an isolation switch; the circuit breaker switch comprises a circuit breaker main shaft, a circuit breaker frame plate and an arc extinguish chamber; the isolation switch comprises an isolation frame plate, an isolation main shaft, a static contact seat, a moving knife, a grounding contact and a static contact. The circuit breaker mechanism drives the main shaft of the circuit breaker to rotate, a cam arranged on the main shaft of the circuit breaker transmits acting force to a connecting pull rod through a roller and a rolling shaft, and then an arc extinguish chamber movable guide rod is driven to move, so that the switching-on and switching-off actions of a circuit breaker switch are realized; the insulation capability is improved by equalizing the electric field through the voltage equalizing cover, and the better insulation effect is achieved.

Description

Technical Field

[0001] This patent application relates to the field of ring main units, and in particular to a ring main unit with an environmentally friendly gas-insulated lower isolating circuit breaker switch. Background Art

[0002] Sulfur hexafluoride (SF6) is a chemically stable and excellent gas insulator widely used for gas insulation in electronic and electrical equipment. While SF6 itself is non-toxic and harmless to humans, it is a greenhouse gas, with a single molecule having a greenhouse effect 22,000 times greater than that of carbon dioxide. It is one of the six greenhouse gases banned under the Kyoto Protocol. While current SF6 emissions are relatively low, long-term environmental and safety considerations necessitate the urgent need for environmentally friendly switchgear to replace SF6-insulated switchgear in the power industry.

[0003] With the continuous advancement and improvement of interruption and insulation technologies, the development of environmentally friendly gas-insulated metal-enclosed switchgear has reached theoretical and technical maturity. Domestic equipment manufacturers have already produced products that have passed form testing and are now in operation. However, most core environmentally friendly components currently on the market use epoxy resin to wrap the live parts, or use insulating panels to separate the live parts to achieve insulation. This use of insulating material to wrap the live parts is complex and essentially uses composite insulation, without achieving gas insulation between the live parts.

[0004] Therefore, it is necessary to improve the existing design technology solutions. Summary of the Invention

[0005] In order to solve the problems pointed out in the above background technology, one purpose of the present invention is to propose an environmentally friendly gas insulated ring network cabinet with a lower isolation circuit breaker switch, which improves the insulation capacity by uniformly forming an electric field with a grading cover and has a better insulation effect.

[0006] The above purpose is achieved through the following technical solutions:

[0007] A ring main unit with an environmentally friendly gas-insulated bottom-isolating circuit breaker switch, comprising a gas box, a circuit breaker mechanism, an isolation mechanism and a bottom-isolating circuit breaker switch;

[0008] The air box is equipped with an expansion sleeve and an inlet and outlet sleeve;

[0009] The circuit breaker mechanism and the isolation mechanism are mounted on the gas tank;

[0010] The lower isolating circuit breaker switch is arranged inside the gas box;

[0011] The lower isolating circuit breaker switch includes a circuit breaker switch and an isolating switch;

[0012] The circuit breaker switch comprises a circuit breaker main shaft, a circuit breaker frame plate, and an arc extinguishing chamber; wherein the circuit breaker frame plate is equipped with two insulating side plates arranged on the left and right; the static end of the arc extinguishing chamber is mounted on the two insulating side plates via a support plate, and the movable end of the arc extinguishing chamber is equipped with a flexible connection and a connecting rod; the connecting rod is equipped with a spring pressure cap, a compression spring, and a roller; the circuit breaker main shaft is mounted on the insulating side plates via a bracket, and cams, rollers, and limit blocks are installed on both sides of the bracket. The roller is mounted on the roller, and the cam is provided with a slide groove that cooperates with the roller. The limit block prevents the roller from falling out of the slide groove;

[0013] The isolating switch comprises an isolating frame plate, an isolating main shaft, a static contact seat, a movable blade, a grounding contact, and a static contact; wherein the isolating switch is mounted below the circuit breaker switch via the isolating frame plate; the rear end of the isolating main shaft is movably mounted on the isolating frame plate, and a transmission crank arm is mounted on the isolating main shaft; the transmission crank arm is mounted on the movable blade, and the root of the movable blade is mounted on the static contact seat; the static contact seat is fixed to the isolating frame plate via an insulator; the static contact is mounted on the support plate of the circuit breaker switch; and the grounding contact is mounted on the isolating frame plate;

[0014] The bracket is also symmetrically provided with a pressure equalizing plate on both sides. The pressure equalizing plate is disc-shaped, with an outer edge having an arc transition surface, a through-hole structure in the middle, and the edge of the through-hole on the inner side of the pressure equalizing plate protrudes to form a flange structure. The main shaft of the circuit breaker passes through the through-hole. There is an arc transition surface between the flange structure and the outer side of the pressure equalizing plate. The outer edge size of the pressure equalizing plate is larger than the outer edge size of the cam.

[0015] The support plate is provided with side bosses on the left and right sides, and the support plate contacts the insulating side plate through the side bosses; the support plate is provided with an upper boss at the connection portion with the static end of the arc extinguishing chamber, and the support plate contacts the static end portion of the arc extinguishing chamber through the upper boss to increase the air gap between the arc extinguishing chamber housing and the support plate; the support plate is provided with a lower boss at the connection portion with the static contact, and the support plate contacts the static contact through the lower boss;

[0016] The circuit breaker switch is further provided with a support plate voltage grading cover, which is installed on the other side of the support plate and the insulating side plate installation position, and the support plate voltage grading cover is provided with a support boss, and the support plate voltage grading cover contacts the insulating side plate through the support boss; the support plate voltage grading cover is provided with a groove for accommodating the fastening screw head;

[0017] Static contact pressure equalizing covers are provided on the left and right sides of the static contact;

[0018] A knife seat pressure equalizing cover is provided at the contact portion between the static contact seat and the movable knife, and the static contact seat uniformly forms an electric field through the knife seat pressure equalizing cover; a groove for accommodating a contact compression spring, a screw and a nut is provided on the knife seat pressure equalizing cover;

[0019] The end of the movable knife is equipped with a blade pressure equalizing cover, which is provided with a groove for accommodating a contact compression spring, a screw and a nut; the edge of the blade pressure equalizing cover is provided with a U-shaped flange structure, and the upper end of the movable knife is embedded in the flange structure of the blade pressure equalizing cover;

[0020] The circuit breaker frame plate and the isolation frame plate are equipped with a pressure-equalizing pad on one side of the fastening nut with the insulating side plate;

[0021] The flexible connection of the circuit breaker switch is connected to the expansion sleeve through a copper bar; the copper bar is L-shaped, the flexible connection overlaps the upper surface of the copper bar's horizontal part, and the copper bar's vertical part overlaps the expansion sleeve;

[0022] The static contact seat of the isolating switch is connected to the inlet and outlet bushings through a copper rod, and a copper rod pressure equalizing cover is provided at the fastening position of the copper rod, the static contact seat and the inlet and outlet bushings, and the copper rod pressure equalizing cover is provided with a groove for accommodating the fastening screw head;

[0023] The circuit breaker mechanism drives the main shaft of the circuit breaker to rotate, and the cam installed on the main shaft of the circuit breaker transmits the force to the connecting rod through the roller and the roller, thereby driving the movable guide rod of the arc extinguishing chamber to move, realizing the closing and opening actions of the circuit breaker switch;

[0024] The isolation mechanism drives the isolation main shaft to rotate, and the transmission crank arm installed on the isolation main shaft transmits the force to the movable knife, thereby realizing the closing and opening actions of the isolation switch.

[0025] In this embodiment, a side expansion equalizing cover is provided at the overlap portion of the copper busbar and the extension sleeve to achieve a uniform electric field; the side expansion equalizing cover is provided with a groove for accommodating the head of a fastening screw.

[0026] In this embodiment, the transmission crank arm includes a main crank arm, a connecting crank arm, a connecting piece, a cantilever shaft and a connecting pin; the main crank arm is installed on the isolation main shaft, the connecting piece is installed between the two movable knives through the connecting pin, one end of the connecting crank arm is movably mounted on the main crank arm through the cantilever shaft, and the other end is also movably mounted on the connecting piece through the cantilever shaft.

[0027] In this embodiment, a large-radius arc surface is used at the bend of the air box near the copper rod in the air box.

[0028] In this embodiment, the insulator is obtained by epoxy resin casting with two inserts; the two inserts are spaced apart and the sides close to each other are both spherical surfaces; a static contact seat pad is installed between the static contact seat and the insulator.

[0029] In this embodiment, a static contact buffer pad is installed on the static contact.

[0030] In this embodiment, a ground contact buffer pad is installed under the ground contact.

[0031] In this embodiment, a gasket is added between the mounting surface of the circuit breaker frame plate and the isolation frame plate and the insulating side plate.

[0032] In this embodiment, the voltage equalizing plate is installed on the left and right sides of the bracket through an aluminum plate support frame. The aluminum plate support frame is located above the bracket and is fastened to the two insulating side plates of the circuit breaker switch. Cantilever beams extend from both sides of the upper end of the aluminum plate support frame, and the inner side of the voltage equalizing plate is fixed on the cantilever beam; the bracket is in contact with the aluminum plate support frame, so that the voltage equalizing plate and the bracket form an equal potential.

[0033] In this embodiment, a rivet nut is provided at a position on the aluminum disk support frame fixed to the insulating side plate, and the flange surface of the rivet nut contacts the insulating side plate.

[0034] Compared with the prior art, the present invention has at least the following beneficial effects:

[0035] 1. This embodiment provides an environmentally friendly gas-insulated ring main unit with a bottom-isolated circuit breaker switch. It improves insulation capability by uniformly distributing the electric field through a voltage-grading cover, and has a better insulation effect. Its overall structure is simple and compact, and can achieve gas insulation between charged parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural diagram of the ring main unit;

[0037] Figure 2 This is a schematic diagram of the assembly inside the air box;

[0038] Figure 3 It is a rear schematic diagram of the lower isolating circuit breaker switch structure;

[0039] Figure 4 It is the right side schematic diagram of the lower isolating circuit breaker switch structure;

[0040] Figure 5 It is an exploded schematic diagram of the assembly structure at the bracket position;

[0041] Figure 6 This is a schematic diagram of the assembly of the fastening parts of the frame and the insulating side panels;

[0042] Figure 7 It is a structural diagram of the support plate;

[0043] Figure 8 It is a structural diagram of the movable knife and transmission arm.

[0044] In the picture:

[0045] 1-air box, 11-expansion casing, 12-inlet and outlet casing, 13-copper busbar, 14-copper rod, 15-copper rod pressure equalizing cover, 16-side expansion pressure equalizing cover, 17-air box bend position;

[0046] 2-circuit breaker mechanism, 3-isolating mechanism;

[0047] 2-4-circuit breaker switch, 41-circuit breaker main shaft, 42-circuit breaker frame plate, 43-arc extinguishing chamber, 44-insulating side plate, 45-support plate, 451-side boss, 452-upper boss, 453-lower boss, 46-flexible connection, 47-connecting rod, 471-spring pressure cap, 472-compression spring, 473-roller, 48-bracket, 481-cam, 482-roller, 483-limiting block, 484-equalizing plate, 485-aluminum plate support frame, 4851-cantilever beam, 4852-rivet nut, 49-support plate equalizing cover, 491-support boss;

[0048] 5-isolating switch, 51-isolating frame plate, 52-isolating main shaft, 53-static contact seat, 531-static contact seat cushion block, 54-moving knife, 541-knife seat pressure equalizing cover, 542-knife edge pressure equalizing cover, 55-grounding contact, 551-grounding contact buffer pad, 56-static contact, 561-static contact pressure equalizing cover, 562-static contact buffer pad, 57-transmission crank arm, 571-main crank arm, 572-connecting crank arm, 573-connecting piece, 574-cantilever shaft, 575-connecting pin, 58-insulator, 581-insert;

[0049] 6-pressure equalizing pad, 7-gasket. DETAILED DESCRIPTION

[0050] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the claimed subject matter. However, those skilled in the art will appreciate that the claimed subject matter can be practiced without these specific details. In addition, methods, devices, or systems well known to those skilled in the art have not been described in detail to avoid obscuring the claimed subject matter.

[0051] Throughout this specification, references to "one embodiment" or "an embodiment" may mean that a particular feature, structure, or characteristic described in connection with a particular embodiment may be included in at least one embodiment of the embodiments comprising the claimed subject matter. Thus, the phrases "in one embodiment" or "an embodiment" appearing in various places throughout this specification are not intended to refer to the same embodiment or to any one particular embodiment being described. Furthermore, it should be understood that the particular features, structures, or characteristics described may be combined in various ways in one or more embodiments. In general, of course, these and other issues will vary with the specific context of application. Therefore, the description of these terms or the specific context of application may provide useful guidance regarding inferences from that context.

[0052] Similarly, the terms "and," "and / or," and "or" as used herein can include various meanings that depend, at least in part, on the context in which the terms are used. Typically, "or" and "and / or" are used in conjunction with a list, such as A, B, or C. When used in an inclusive sense, they mean A, B, and C, and when used in an exclusive sense, they mean A, B, or C. Furthermore, the terms "one or more" as used herein are used to describe any feature, structure, or characteristic alone, or to describe some combination of features, structures, or characteristics. However, it should be noted that this is merely an illustrative example, and the subject matter protected by the claims is not limited to this example.

[0053] As used to describe these embodiments, the terms "above", "below", "upper", "lower" and "side" describe positions relative to the optical axis of such a small imaging module. In particular, "above" and "below" refer to positions along the optical axis, where "above" refers to one side of the element and "below" refers to the other side of the element. With respect to such "above" and "below", "side" refers to the side of the element away from the optical axis, such as the periphery of a lens. It should also be understood that such terms are not used to refer to directions defined by gravity or any other particular orientation. Instead, such terms are merely used to identify one part from another. Therefore, "upper" and "lower" can be interchanged with "top" and "bottom", "first" and "second", "left" and "right", etc., which are equivalent.

[0054] It should be noted that throughout the specification and claims herein, when one component is "fixed" to another component, it means that one component is fixed to another component by any feasible method, including but not limited to adhesives, heat riveting, mortise and tenon joints, screws, welding (such as soldering, laser welding, ultrasonic welding, fusion welding), hole-column mechanism tight fitting, or concave-convex mechanism tight fitting, etc., any one of which is used independently or in combination of more than one method.

[0055] It will be understood that the present application is not limited to the preferred embodiments described herein and that, of course, various modifications or changes may be made without departing from the scope of protection defined herein.

[0056] like Figures 1 to 8 As shown, this embodiment provides a ring main unit with an environmentally friendly gas-insulated bottom-isolating circuit breaker switch, comprising a gas box 1, a circuit breaker mechanism 2, an isolation mechanism 3 and a bottom-isolating circuit breaker switch;

[0057] The air box 1 is equipped with an expansion sleeve 11 and an inlet and outlet sleeve 12;

[0058] The circuit breaker mechanism 2 and the isolation mechanism 3 are mounted on the gas box 1;

[0059] The lower isolating circuit breaker switch is arranged inside the gas box 1;

[0060] The lower isolating circuit breaker switch includes a circuit breaker switch 4 and an isolating switch 5;

[0061] The circuit breaker switch 4 includes a circuit breaker main shaft 41, a circuit breaker frame plate 42 and an arc extinguishing chamber 43; wherein the circuit breaker frame plate 42 is equipped with two insulating side plates 44 arranged on the left and right; the static end of the arc extinguishing chamber 43 is mounted on the two insulating side plates 44 via a support plate 45, and the movable end of the arc extinguishing chamber 43 is installed with a soft connection 46 and a connecting rod 47; the connecting rod 47 is equipped with a spring pressure cap 471, a compression spring 472 and a roller 473; the circuit breaker main shaft 41 is mounted on the insulating side plates 44 via a bracket 48, and a cam 481, a roller 482 and a limit block 483 are installed on both sides of the bracket 48. The roller 482 is mounted on the roller 473, and the cam 481 is provided with a slide groove that cooperates with the roller 482. The limit block 483 prevents the roller 482 from falling out of the slide groove;

[0062] The isolating switch 5 includes an isolating frame plate 51, an isolating spindle 52, a static contact seat 53, a movable blade 54, a grounding contact 55, and a static contact 56. The isolating switch 5 is mounted below the circuit breaker switch 4 via the isolating frame plate 51. The rear end of the isolating spindle 52 is movably mounted on the isolating frame plate 51. A transmission crank arm 57 is mounted on the isolating spindle 52. The movable blade 54 is mounted on the transmission crank arm 57. The root of the movable blade 54 is mounted on the static contact seat 53. The static contact seat 53 is fixed to the isolating frame plate 51 via an insulator 58. The static contact 56 is mounted on the support plate 45 of the circuit breaker switch 4. The grounding contact 55 is mounted on the isolating frame plate 51.

[0063] The bracket 48 is also symmetrically provided with equalizing plates 484 on both sides. The equalizing plates 484 are disc-shaped, with an outer edge having an arc transition surface with a radius of R10. The middle portion is a through-hole structure. The edge of the through-hole on the inner side of the equalizing plate 484 protrudes to form a flange structure. The circuit breaker main shaft 41 passes through the through-hole. There is an arc transition surface with a radius of R6 between the flange structure and the outer side surface of the equalizing plate 484. The outer edge size of the equalizing plate 484 is larger than the outer edge size of the cam 481. The uniform electric field effect of the arc transition surface on the outer edge of the equalizing plate 484 shields the tip electric field at the position of the bracket 48, thereby achieving a uniform electric field effect and improving the insulation capacity.

[0064] The support plate 45 is provided with side bosses 451 on the left and right sides, and the support plate 45 is in contact with the insulating side plate 44 through the side bosses 451; the support plate 45 is provided with an upper boss 452 at the connection part with the static end of the arc extinguishing chamber 43, and the support plate 45 is in contact with the static end of the arc extinguishing chamber 43 through the upper boss 452 to increase the air gap between the outer shell of the arc extinguishing chamber 43 and the support plate 45; the support plate 45 is provided with a lower boss 453 at the connection part with the static contact 56, and the support plate 45 is in contact with the static contact 56 through the lower boss 453; specifically, the support plate 45 is provided with two side bosses 451 with an outer diameter of 16mm and a height of 2mm on the left and right sides, and is in contact with the insulating side plate 44 through the side bosses 451; the support plate 45 and the arc extinguishing chamber 43 are connected. An upper boss 452 is provided at the static end connection of the arc extinguishing chamber 43. The outer diameter of the upper boss 452 is 2-4 mm larger than the outer diameter of the guide rod at the static end of the arc extinguishing chamber 43. The upper boss 452 is 1 mm high and contacts the static end of the arc extinguishing chamber 43 through the upper boss 452. A lower boss 453 is provided at the connection between the support plate 45 and the static contact 56. The lower boss 453 is 1 mm high and has the same planar shape as the overlapping surface of the static contact 56. The outer edge size of the plane of the lower boss 453 is 1-2 mm larger than the outer edge size of the overlapping surface of the static contact 56. Contacts the static contact 56 through the lower boss 453. The support plate 45 increases the air gap between it and other components through the boss structure, optimizes the phenomenon of local discharge at the overlapping portion, and improves the insulation capacity.

[0065] The circuit breaker switch 4 is also provided with a support plate voltage-equalizing cover 49, which is installed on the other side of the installation position of the support plate 45 and the insulating side plate 44. The support plate voltage-equalizing cover 49 is provided with two support bosses 491 with an outer diameter of 16 mm and a height of 2 mm. The support plate voltage-equalizing cover 49 contacts the insulating side plate 44 through the support bosses 491, reducing the contact area between the support bosses 491 and the insulating side plate 44 and increasing the air gap between the support bosses 491 and the insulating side plate 44; the support plate voltage-equalizing cover 49 is provided with a groove for accommodating the head of the fastening screw. The uniform electric field effect of the support plate voltage-equalizing cover 49 shields the tip electric field of the fastening screw, thereby achieving a uniform electric field effect and improving the insulation capacity;

[0066] The static contact 56 is provided with a static contact grading cover 561 on the left and right sides. The static contact grading cover 561 is annular and shields the electric field at the tip of the fastening screw of the static contact 56 through the uniform electric field effect of the static contact grading cover 561, thereby improving the insulation capability.

[0067] A knife seat pressure equalizing cover 541 is provided at the contact portion between the static contact seat 53 and the movable knife 54. The static contact seat 53 is subjected to a uniform electric field through the knife seat pressure equalizing cover 541. The knife seat pressure equalizing cover 541 is provided with grooves for accommodating contact compression springs, screws and nuts. The uniform electric field effect of the knife seat pressure equalizing cover 541 shields the electric field at the tip of the fastening screw, thereby achieving a uniform electric field effect and improving insulation capability.

[0068] The end of the movable blade 54 is provided with a blade pressure equalizing cover 542, which is provided with a groove for accommodating a contact compression spring, a screw, and a nut; the edge of the blade pressure equalizing cover 542 is provided with a U-shaped flange structure, and the upper end of the movable blade 54 is embedded in the flange structure of the blade pressure equalizing cover 542;

[0069] The circuit breaker frame plate 42 and the isolation frame plate 51 are equipped with a pressure-equalizing pad 6 on the side of the fastening nut with the insulating side plate 44 to eliminate the electric field concentration phenomenon at the fastening part, uniformize the electric field, and improve the insulation capacity;

[0070] The flexible connection 46 of the circuit breaker switch 4 is connected to the extension sleeve 11 via the copper busbar 13. The copper busbar 13 is L-shaped, and the flexible connection 46 overlaps the upper surface of the horizontal portion of the copper busbar 13. The uniform electric field effect of the rounded corners of the copper busbar 13 itself uniformizes the electric field at the edge of the flexible connection 46 at the overlap portion. The vertical portion of the copper busbar 13 overlaps the extension sleeve 11.

[0071] The static contact seat 53 of the disconnector 5 is connected to the inlet and outlet bushings 12 via a copper rod 14. A copper rod pressure-equalizing cover 15 is provided at the fastening position of the copper rod 14, the static contact seat 53, and the inlet and outlet bushings 12. The copper rod pressure-equalizing cover 15 has a groove for accommodating the head of the fastening screw. The copper rod pressure-equalizing cover 15 uniformly forms the electric field, thereby improving the insulation capacity.

[0072] The circuit breaker mechanism 2 drives the circuit breaker main shaft 41 to rotate, and the cam 481 installed on the circuit breaker main shaft 41 transmits the force to the connecting rod 47 through the roller 482 and the roller 473, thereby driving the moving guide rod of the arc extinguishing chamber 43 to move, thereby realizing the closing and opening actions of the circuit breaker switch 4; during the closing process, the roller 473 drives the spring pressure cap 471 to move downward to compress the compression spring 472. After the closing action is completed, the compression spring 472 will apply a reverse elastic force to the connecting rod 47 to form a closing holding force.

[0073] The isolation mechanism 3 drives the isolation main shaft 52 to rotate, and the transmission crank arm 57 installed on the isolation main shaft 52 transmits the force to the movable knife 54, thereby realizing the closing and opening actions of the isolation switch 5.

[0074] The isolation main shaft 52 and the transmission crank arm 57 are linked to drive the movable knife to rotate with the static contact seat 53 as the fulcrum, so that the upper end of the movable knife 54 and the static contact 56 form an on-off switch; the isolation mechanism 3 drives the isolation main shaft 52 to rotate, and the transmission crank arm 57 installed on the isolation main shaft 52 transmits the force to the movable knife 54, thereby realizing the closing and opening actions of the isolation switch 5.

[0075] The present embodiment provides an environmentally friendly gas-insulated ring main unit with a bottom-isolated circuit breaker switch, which improves insulation capability by uniformly distributing the electric field through a voltage-grading cover, and has a better insulation effect. The overall structure is simple and compact, and gas insulation can be achieved between charged bodies.

[0076] A side expansion equalizing cover 16 is provided at the joint between the copper busbar 13 and the expansion sleeve 11. The side expansion equalizing cover 16 has a groove for accommodating the head of the fastening screw. The side expansion equalizing cover 16 is used to uniformly form the electric field and improve the insulation capacity.

[0077] The transmission crank arm 57 includes a main crank arm 571, a connecting crank arm 572, a connecting piece 573, a cantilever shaft 574 and a connecting pin 575; the main crank arm 571 is installed on the isolation main shaft 52, and the connecting piece 573 is installed between the two movable knives 54 through the connecting pin 575. One end of the connecting crank arm 572 is movably mounted on the main crank arm 571 through the cantilever shaft 574, and the other end is also movably mounted on the connecting piece 573 through the cantilever shaft 574. The main crank arm 571, the connecting crank arm 572, the connecting piece 573 and the cantilever shaft 574 are made of a mixture of PC and glass fiber materials.

[0078] In the air box 1, the air box bend position 17 close to the copper rod 14 adopts a large-angle arc surface with a radius of R25, so that the electric field is uniformed by the arc surface, thereby improving the insulation capacity.

[0079] The insulator 58 is obtained by epoxy resin casting with two inserts 581; the two inserts 581 are separated by a certain distance and the sides close to each other are both spherical surfaces. A uniform electric field is generated through the spherical surfaces, and there is no need to add skirts, while reducing the overall length of the insulator; a static contact seat cushion block 531 is installed between the static contact seat 53 and the insulator 58. The thickness of the static contact seat cushion block 531 is 3 mm. The static contact seat cushion block 531 reduces the contact area between the static contact seat 53 and the insulator 58, increases the air gap between the static contact seat 53 and the insulator 58, optimizes the phenomenon of local discharge in this part, and improves the insulation capacity.

[0080] A static contact buffer pad 562 is installed on the static contact 56. The static contact buffer pad 562 can provide a buffer force when the movable knife 54 is isolated and closed, thereby preventing the movable knife 54 from closing overshoot.

[0081] A grounding contact buffer pad 551 is installed under the grounding contact 55. The grounding contact buffer pad 551 can provide a buffer force when the movable knife 54 is grounded and closed, preventing the blade edge pressure equalizing cover 542 at the end of the movable knife 54 from impact and deformation, thereby effectively protecting the uniform electric field effect of the blade edge pressure equalizing cover 542.

[0082] A gasket 7 is added between the mounting surface of the circuit breaker frame plate 42 and the isolation frame plate 51 and the insulating side plate 44. The gasket 7 reduces the contact area between the circuit breaker frame plate 42 and the isolation frame plate 51 and the insulating side plate 44, increases the air gap between the insulating side plate 44 and the circuit breaker frame plate 42 and the isolation frame plate 51, optimizes the phenomenon of local discharge in this area, and improves the insulation capacity.

[0083] The voltage-equalizing plate 484 is mounted on the left and right sides of the bracket 48 via an aluminum plate support frame 485. The aluminum plate support frame 485 is located above the bracket 48 and is fastened to the two insulating side plates 44 of the circuit breaker switch 4. Extending from both sides of the upper end of the aluminum plate support frame 485 are cantilever beams 4851, and the inner side of the voltage-equalizing plate 484 is fixed to the cantilever beams 4851. The bracket 48 is in contact with the aluminum plate support frame 485, so that the voltage-equalizing plate 484 and the bracket 48 form an equipotential. A rivet nut 4852 is provided at the position on the aluminum plate support frame 485 that is fixed to the insulating side plate 44. The flange surface of the rivet nut 4852 contacts the insulating side plate 44. This reduces the contact area between the aluminum plate support frame 485 and the insulating side plate 44, increases the air gap between the aluminum plate support frame 485 and the insulating side plate 44, optimizes the phenomenon of local discharge at the overlapped portion, and improves the insulation capacity.

[0084] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A ring main unit with an environmentally friendly gas-insulated bottom-isolating circuit breaker switch, comprising a gas box (1), a circuit breaker mechanism (2), an isolation mechanism (3) and a bottom-isolating circuit breaker switch; The air box (1) is provided with an expansion sleeve (11) and an inlet and outlet sleeve (12); The circuit breaker mechanism (2) and the isolation mechanism (3) are mounted on the gas box (1); The lower isolating circuit breaker switch is arranged inside the gas box (1); The lower isolating circuit breaker switch comprises a circuit breaker switch (4) and an isolating switch (5); The circuit breaker switch (4) comprises a circuit breaker main shaft (41), a circuit breaker frame plate (42) and an arc extinguishing chamber (43); wherein, The circuit breaker frame plate (42) is provided with two insulating side plates (44) arranged on the left and right; the static end of the arc extinguishing chamber (43) is installed on the two insulating side plates (44) through a support plate (45), and the moving end of the arc extinguishing chamber (43) is provided with a soft connection (46) and a connecting rod (47); the connecting rod (47) is provided with a spring pressure cap (471), a compression spring (472) and a roller (473); the circuit breaker main shaft (41) is installed on the insulating side plates (44) through a bracket (48), and cams (481), rollers (482) and limit blocks (483) are provided on both sides of the bracket (48); the roller (482) is installed on the roller (473), and a sliding groove matching the roller (482) is provided on the cam (481), and the roller (482) is prevented from falling out of the sliding groove by the limit block (483); The isolating switch (5) comprises an isolating frame plate (51), an isolating main shaft (52), a static contact seat (53), a movable blade (54), a grounding contact (55) and a static contact (56); wherein the isolating switch (5) is mounted below the circuit breaker switch (4) through the isolating frame plate (51); the rear end of the isolating main shaft (52) is movably mounted on the isolating frame plate (51), and a transmission crank arm (57) is mounted on the isolating main shaft (52); the transmission crank arm (57) is mounted on the movable blade (54), and the root of the movable blade (54) is mounted on the static contact seat (53); the static contact seat (53) is fixed to the isolating frame plate (51) through an insulator (58); the static contact (56) is mounted on the support plate (45) of the circuit breaker switch (4); and the grounding contact (55) is mounted on the isolating frame plate (51); Its characteristics are: The bracket (48) is also symmetrically provided with a pressure equalizing plate (484) on both sides. The pressure equalizing plate (484) is disc-shaped, has an outer edge with a circular arc transition surface, and a through-hole structure in the middle. The through-hole edge on the inner side of the pressure equalizing plate (484) protrudes to form a flange structure. The circuit breaker main shaft (41) passes through the through-hole. There is a circular arc transition surface between the flange structure and the outer side surface of the pressure equalizing plate (484). The outer edge size of the pressure equalizing plate (484) is larger than the outer edge size of the cam (481). The support plate (45) is provided with side bosses (451) on both sides, and the support plate (45) contacts the insulating side plate (44) through the side bosses (451); the support plate (45) is provided with an upper boss (452) at the connection portion with the static end of the arc extinguishing chamber (43), and the support plate (45) contacts the static end portion of the arc extinguishing chamber (43) through the upper boss (452) to increase the air gap between the arc extinguishing chamber (43) shell and the support plate (45); the support plate (45) is provided with a lower boss (453) at the connection portion with the static contact (56), and the support plate (45) contacts the static contact (56) through the lower boss (453); The circuit breaker switch (4) is further provided with a support plate voltage-equalizing cover (49), which is correspondingly mounted on the other side of the mounting portion of the support plate (45) and the insulating side plate (44), and the support plate voltage-equalizing cover (49) is provided with a support boss (491), and the support plate voltage-equalizing cover (49) contacts the insulating side plate (44) through the support boss (491); the support plate voltage-equalizing cover (49) is provided with a groove for accommodating a fastening screw head; Static contactor pressure equalizing covers (561) are provided on the left and right sides of the static contactor (56); A knife seat pressure equalizing cover (541) is provided at the contact portion between the static contact seat (53) and the movable knife (54), and the static contact seat (53) uniformly forms an electric field through the knife seat pressure equalizing cover (541); a groove for accommodating a contact pressure spring, a screw and a nut is provided on the knife seat pressure equalizing cover (541); The end of the movable knife (54) is provided with a knife-edge pressure-equalizing cover (542), and the knife-edge pressure-equalizing cover (542) is provided with a groove for accommodating a contact pressure spring, a screw and a nut; a U-shaped flange structure is provided at the edge of the knife-edge pressure-equalizing cover (542), and the upper end of the movable knife (54) is embedded in the flange structure of the knife-edge pressure-equalizing cover (542); The circuit breaker frame plate (42) and the isolation frame plate (51) are provided with a pressure-equalizing pad (6) on one side of the fastening nut with the insulating side plate (44); The flexible connection (46) of the circuit breaker switch (4) is connected to the expansion sleeve (11) through the copper bar (13); the copper bar (13) is L-shaped, the flexible connection (46) is overlapped on the upper surface of the horizontal part of the copper bar (13), and the vertical part of the copper bar (13) is overlapped with the expansion sleeve (11); The static contact seat (53) of the isolating switch (5) is connected to the inlet and outlet bushings (12) via a copper rod (14), and a copper rod pressure equalizing cover (15) is provided at the fastening position between the copper rod (14), the static contact seat (53) and the inlet and outlet bushings (12), and the copper rod pressure equalizing cover (15) is provided with a groove for accommodating the head of a fastening screw; The circuit breaker mechanism (2) drives the circuit breaker main shaft (41) to rotate, and the cam (481) installed on the circuit breaker main shaft (41) transmits the force to the connecting rod (47) through the roller (482) and the roller (473), thereby driving the moving guide rod of the arc extinguishing chamber (43) to move, thereby realizing the closing and opening actions of the circuit breaker switch (4); The isolating mechanism (3) drives the isolating main shaft (52) to rotate, and the transmission crank arm (57) installed on the isolating main shaft (52) transmits the force to the movable knife (54), thereby realizing the closing and opening actions of the isolating switch (5).

2. The ring main unit of an environmentally friendly gas-insulated bottom-disconnected circuit breaker switch according to claim 1, characterized in that: A side expansion equalizing cover (16) is provided at the overlap portion between the copper busbar (13) and the expansion sleeve (11), and a uniform electric field is achieved through the side expansion equalizing cover (16); the side expansion equalizing cover (16) is provided with a groove for accommodating a fastening screw head.

3. The ring main unit of an environmentally friendly gas-insulated bottom-disconnected circuit breaker switch according to claim 2, characterized in that: The transmission crank arm (57) comprises a main crank arm (571), a connecting crank arm (572), a connecting piece (573), a cantilever shaft (574) and a connecting pin (575); the main crank arm (571) is mounted on the isolation main shaft (52); the connecting piece (573) is mounted between the two movable blades (54) via the connecting pin (575); one end of the connecting crank arm (572) is movably mounted on the main crank arm (571) via the cantilever shaft (574); and the other end is also movably mounted on the connecting piece (573) via the cantilever shaft (574).

4. The ring main unit of an environmentally friendly gas-insulated bottom-disconnected circuit breaker switch according to claim 1, characterized in that: In the air box (1), the air box bend position (17) close to the copper rod (14) adopts a large-radius arc surface.

5. The ring main unit of an environmentally friendly gas-insulated bottom-disconnected circuit breaker switch according to claim 1, 2, 3 or 4, characterized in that: The insulator (58) is obtained by epoxy resin casting from two inserts (581); the two inserts (581) are spaced apart by a certain distance and both sides close to each other are spherical surfaces; a static contact seat cushion block (531) is installed between the static contact seat (53) and the insulator (58).

6. The ring main unit of an environmentally friendly gas-insulated bottom-disconnected circuit breaker switch according to claim 1, 2, 3 or 4, characterized in that: A static contact buffer pad (562) is installed on the static contact (56).

7. The ring main unit of an environmentally friendly gas-insulated bottom-disconnecting circuit breaker switch according to claim 1, 2, 3 or 4, characterized in that: A ground contact buffer pad (551) is installed below the ground contact (55).

8. The ring main unit of an environmentally friendly gas-insulated bottom-disconnected circuit breaker switch according to claim 1, 2, 3, or 4, characterized in that: A gasket (7) is added between the circuit breaker frame plate (42) and the isolation frame plate (51) and the mounting surface of the insulating side plate (44).

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