Composite insulator and composite cross arm

Abstract

The composite insulator comprises an insulator, a sheath wrapping the periphery of the insulator and flanges arranged at the two ends of the insulator in a sleeving mode, each flange comprises a flange cylinder and a flange plate, each flange cylinder comprises a first end and a second end which are oppositely arranged in the axial direction of the flange cylinder, and the flange plates seal the first ends of the flange cylinders; the end portion of the insulator is inserted into the inner wall of the flange cylinder from the second end of the flange cylinder and abuts against the flange plate. A connecting groove is formed in the second end of the flange cylinder and extends outwards in the radial direction of the flange cylinder on the inner wall of the flange cylinder, a first step face is formed between the connecting groove and the inner wall of the flange cylinder, and a sealing ring and a sealing structure are arranged in a cavity formed between the outer wall of the sheath and the peripheral wall of the connecting groove. And the sealing structure extends to cover the periphery of the flange and the periphery of the sheath. The invention further discloses a composite cross arm comprising the composite insulator.

Description

Technical Field

[0001] The present application relates to the technical field of transmission insulation equipment, and particularly to a composite insulator and a composite cross arm. Background Art

[0002] During the operation of the composite insulator in the existing composite cross arm, if the end seal fails, external moisture and water will invade the interior of the composite insulator along the end seal position, triggering partial discharge and gradually developing into an arc connecting the upper and lower flanges, resulting in non-self-recovery damage to the internal insulation of the composite insulator. In severe cases, it may even cause the composite insulator to explode and crack due to a sharp increase in internal pressure, leading to a tripping and power outage accident.

[0003] For the existing sealant structure at the flange end of the composite insulator, on the one hand, there is a problem of a short interface length. On the other hand, since the sealant uses room temperature glue, its aging resistance performance is far inferior to that of high temperature vulcanized silicone rubber. If it operates in a high humidity and high temperature environment for a long time, especially during the rainy season, there is a risk of external moisture invading along the paths of the sealant surface, the inner surface of the flange, and the inner wall of the composite insulator tube. Therefore, it is necessary to design a flange end seal strengthening structure scheme for the current composite insulator products. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present application is to provide a composite insulator and a composite cross arm with good flange end sealing effect, avoiding accidents such as internal flashover of the composite insulator due to long-term seal failure.

[0005] To achieve the above purpose, the technical means adopted in the present application are as follows: A composite insulator includes an insulator, a sheath covering the outer periphery of the insulator, and flanges sleeved at both ends of the insulator. The flange includes a flange barrel and a flange plate. The flange barrel includes a first end and a second end oppositely arranged along its axial direction. The flange plate covers the first end of the flange barrel. The end of the insulator is inserted into the inner wall of the flange barrel from the second end of the flange barrel and abuts against the flange plate. A connecting groove is provided at the second end of the flange barrel. The connecting groove extends radially outward along the inner wall of the flange barrel. A first step surface is formed between the connecting groove and the inner wall of the flange barrel. A sealing ring and a sealing structure are arranged in the cavity formed between the outer wall of the sheath and the peripheral wall of the connecting groove. The sealing structure extends to cover the outer periphery of the flange and the outer periphery of the sheath.

[0006] In one embodiment, the sealing structure is made of high temperature vulcanized silicone rubber.

[0007] In one embodiment, the sheath is made of high temperature vulcanized silicone rubber, and the sealing structure has a smooth transition with the outer peripheral surface of the sheath.

[0008] In one embodiment, the sealing ring is located between the outer wall of the sheath and the peripheral wall of the connecting groove.

[0009] In one embodiment, the sealing ring is located between the end of the sheath and the first stepped surface.

[0010] In one embodiment, the sealing ring includes a first sealing ring and a second sealing ring. The first sealing ring is located between the outer wall of the sheath and the peripheral wall of the connecting groove, and the second sealing ring is located between the end face of the sheath and the first stepped surface.

[0011] In one embodiment, in the axial direction of the composite insulator, the distance between the farthest position where the sealing structure extends to the outer periphery of the flange and the second end of the flange cylinder is 7 mm to 12 mm.

[0012] In one embodiment, in the axial direction of the composite insulator, the distance between the farthest position where the sealing structure extends to the outer periphery of the sheath and the second end of the flange cylinder is 12 mm to 15 mm.

[0013] In one embodiment, in the axial direction of the composite insulator, the sealing structure includes a first sealing area, a second sealing area, and a third sealing area. The first sealing area covers the outer periphery of the flange, the second sealing area covers the outer periphery of the sheath, and the third sealing area is filled between the outer wall of the sheath and the peripheral wall of the connecting groove.

[0014] In one embodiment, the thickness of the first sealing area covering the outer periphery of the flange is 3 mm to 5 mm, and the thickness of the second sealing area covering the outer periphery of the sheath is equal to the sum of the thickness of the first sealing area and the radial distance from the outer wall of the sheath to the outer wall of the flange.

[0015] To achieve the above object, another technical means adopted in this application is as follows: A composite cross arm includes the aforementioned composite insulator.

[0016] The beneficial effects of this application are: Different from the prior art, the composite insulator of this application sets a high-performance sealing structure at the end face of the connection between the insulator and the flange, that is, in the form of encapsulation with high-temperature vulcanized silicone rubber. On the one hand, it effectively extends the sealing length of the sealing structure between the flange and the sheath, improves the safety distance for preventing water vapor from invading the inner wall of the flange, and plays a sealing role to the greatest extent; on the other hand, it ensures the consistency of the sealing structure material and the sheath material, thereby effectively improving the interface sealing effect and aging resistance of the sealing structure. At the same time, it can also shorten the preparation time, improve production efficiency, and improve the performance quality of the finished product. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of a composite insulator 100 according to an embodiment of this application;

[0018] Figure 2 is a partial schematic diagram of the sealing part of the flange 130 and the sheath 120 according to an embodiment of this application;

[0019] Figure 3 It is a partial schematic view of the sealing part between the flange 130 and the sheath 120 according to another embodiment of the present application;

[0020] Figure 4 It is a partial schematic view of the sealing part between the flange 130 and the sheath 120 according to still another embodiment of the present application. Detailed implementation manners

[0021] According to the requirements, the detailed implementation manners of the present application will be disclosed here. However, it should be understood that the implementation manners disclosed here are only typical examples of the present application, which can be embodied in various forms. Therefore, the specific details disclosed here are not considered restrictive, but only serve as the basis for the claims and as a representative basis for teaching those skilled in the art to apply the present application in any appropriate manner in practice, including adopting various features disclosed here and combining features that may not be explicitly disclosed here.

[0022] As Figure 1 shown, the present application provides a composite insulator 100, which includes an insulator 110, a sheath 120 wrapped around the outer periphery of the insulator 110, and flanges 130 sleeved on both ends of the insulator 110. A plurality of umbrella skirts 140 extend radially along the outer edge of the sheath 120, and the plurality of umbrella skirts 140 are arranged at intervals along the axial direction of the composite insulator 100. The flange 130 includes a flange cylinder 131 and a flange plate 132. The flange cylinder 131 includes a first end 1311 and a second end 1312 oppositely arranged along its axial direction. The flange plate 132 seals the first end 1311 of the flange cylinder 131. The end of the insulator 110 is inserted into the inner wall of the flange cylinder 131 from the second end 1312 of the flange cylinder 131 and abuts against the flange plate 1321, and then the flange 130 is sleeved and fixed at the end of the insulator 110. Among them, two flanges 130 are provided, which are respectively sleeved and fixed at both ends of the insulator 110 for connecting the composite insulator 100 to other devices and apparatuses.

[0023] The insulator 110 can be a solid insulating core or a hollow insulating tube. Among them, when the insulator 110 is a solid insulating core, it can be a solid core rod formed by winding, pultruding, or pultruding and winding glass fiber or aramid fiber impregnated with epoxy resin. When the insulator 110 is a hollow insulating tube, it can be a hollow pultruded tube formed by pultruding and winding glass fiber or aramid fiber impregnated with epoxy resin, or a glass steel tube formed by winding and curing or pultruding glass fiber impregnated with epoxy resin, or an aramid fiber tube formed by winding and curing aramid fiber impregnated with epoxy resin, which is not limited here. At the same time, the sheath 120 and the umbrella skirts 140 are made of high-temperature vulcanized silicone rubber.

[0024] Combined with Figure 2As shown, in one embodiment, the flange 130 further includes a first connection groove 133 located at the second end 1312 of the flange cylinder 131. The first connection groove 133 extends radially outward along the inner wall of the flange cylinder 131. The diameter of the first connection groove 133 is greater than the diameter of the inner wall of the flange cylinder 131 and less than the diameter of the outer wall of the flange cylinder 131. Consequently, a first step surface 134 is formed between the first connection groove 133 and the inner wall of the flange cylinder 131. When the insulator 110 is inserted into the inner wall of the flange cylinder 131 and abuts against the flange plate 132, the end surface of the sheath 120 abuts against the first step surface 134, ensuring a firm connection between the insulator 110 and the flange 130.

[0025] Continue to refer to Figure 2 , the outer diameter of the sheath 120 is less than the diameter of the first connection groove 133, forming a cavity between the outer wall of the sheath 120 and the peripheral wall of the first connection groove 133. A first sealing ring 150 is disposed in this cavity, that is, the first sealing ring 150 is located between the outer wall of the sheath 120 and the peripheral wall of the first connection groove 133. The first sealing ring 150 abuts against the outer wall of the sheath 120, the peripheral wall of the first connection groove 133, and the first step surface 134 simultaneously, fully sealing the sheath 120 and the flange 130 to prevent external dirt, moisture, etc. from entering the flange 130. In other embodiments, the first sealing ring may also be disposed between the end surface of the sheath and the first step surface, which is not limited herein.

[0026] Meanwhile, the remaining part of the cavity formed between the outer wall of the sheath 120 and the peripheral wall of the first connection groove 133 after accommodating the first sealing ring 150 is covered with a sealing structure 160, and the sealing structure 160 extends to cover the outer periphery of the flange 130 and the outer periphery of the sheath 120. In the axial direction of the composite insulator 100, the sealing structure 160 includes a first sealing region 161, a second sealing region 162, and a third sealing region. The first sealing region 161 covers the outer periphery of the flange 130, the second sealing region 162 covers the outer periphery of the sheath 120, and the third sealing region fills the space between the outer wall of the sheath 120 and the peripheral wall of the first connection groove 133. Among them, in the radial direction of the composite insulator 100, the thickness of the first sealing region 161 covering the outer periphery of the flange 130 is 3 mm to 5 mm; the thickness of the second sealing region 162 covering the outer periphery of the sheath 120 is equal to the sum of the thickness of the first sealing region 161 and the radial distance from the outer wall of the sheath 120 to the outer wall of the flange 130, so that the outer peripheral surfaces of the first sealing region 161 and the second sealing region 162 coincide, and both the first sealing region 161 and the second sealing region 162 are annular, making the thickness of the sealing structure 160 uniform and ensuring the overall mechanical strength of the sealing structure 160; the thickness of the third sealing region is equal to the radial distance between the outer wall of the sheath 120 and the peripheral wall of the first connection groove 133.

[0027] Further, in the axial direction of the composite insulator 100, the distance L1 between the farthest position where the sealing structure 160 extends to the outer periphery of the flange 130 and the second end 1312 of the flange cylinder 131 is the length of the first sealing area 161, and the range of L1 is 7 mm to 12 mm; the distance L2 between the farthest position where the sealing structure 160 extends to the outer periphery of the sheath 120 and the second end 1312 of the flange cylinder 131 is the length of the second sealing area 162, and the range of L2 is 12 mm to 15 mm. In this way, it is ensured that the interface sealing length between the flange 130 and the sheath 120 is relatively long, the safety distance for preventing water vapor from invading the inner wall of the flange 130 is increased, the sealing effect is maximally achieved, and the aging of the sealing structure 160 after long-term operation is prevented, resulting in sealing failure. The sealing structure 160 in this embodiment is applicable to the process of vertically bonding the insulator 110 and the flange 130, and the injection of the adhesive liquid can be observed from above during the vertical bonding process.

[0028] Among them, the sealing structure 160 is made of high-temperature vulcanized silicone rubber. After the flange 130 is sleeved and fixed at the end of the insulator 110, an injection mold is sleeved on the outer periphery of the connection between the flange 130 and the sheath 120. The injection mold is filled with silicone rubber compound. After heating and pressurizing for a certain period of time, the silicone rubber compound in the injection mold is vulcanized and formed to form the sealing structure 160 of high-temperature vulcanized silicone rubber. The injection-molded sealing structure 160 is trimmed to make the outer peripheral surface of the sealing structure 160 and the sheath 120 have a smooth transition.

[0029] In the prior art, room-temperature vulcanized silicone rubber is used for sealing at the connection between the flange and the sheath. However, the aging resistance of room-temperature vulcanized silicone rubber is far inferior to that of high-temperature vulcanized silicone rubber. Especially under high-temperature and high-humidity conditions for a long time, it is prone to sealing failure, resulting in the invasion of external water vapor and accelerating the corrosion and aging of the composite insulator insulator. Therefore, the sealing structure 160 made of high-temperature vulcanized silicone rubber is adopted in this application, which can further strengthen the sealing between the flange 130 and the sheath 120. Compared with the traditional manual operation method for sealing with room-temperature vulcanized silicone rubber, this application can effectively avoid the performance differences of the composite insulator 100 caused by different operator levels. At the same time, after the room-temperature vulcanized silicone rubber is coated at the connection between the sheath and the flange, it needs to be left standing at room temperature for 8 to 12 hours to be completely cured, while the high-temperature vulcanized silicone rubber only needs to be heated and pressurized for about 2 hours to be cured. Therefore, the sealing structure 160 made of high-temperature vulcanized silicone rubber in this application can also shorten the preparation time, thereby improving production efficiency. Since the sheath 120 also uses high-temperature vulcanized silicone rubber, the materials of the sealing structure 160 and the sheath 120 are the same, further ensuring excellent interface sealing effect and aging resistance between the flange 130 and the sheath 120, and greatly improving the insulation life of the composite insulator 100.

[0030] Combined withFigure 3 As shown, in another embodiment, a second connection groove 135 is further provided on the flange cylinder 131. The second connection groove 135 extends radially outward along the inner wall of the flange cylinder 131, and the second connection groove 135 is disposed adjacent to the first connection groove 133 on a side of the first connection groove 133 away from the second end 1312 of the flange cylinder 131. The diameter of the second connection groove 135 is larger than the diameter of the inner wall of the flange cylinder 131 and smaller than the diameter of the first connection groove 133. Then, a first step surface 134 is formed between the second connection groove 135 and the inner wall of the flange cylinder 131, and a second step surface 136 is formed between the second connection groove 135 and the first connection groove 133.

[0031] The outer diameter of the sheath 120 is slightly smaller than the diameter of the second connection groove 135. The sheath 120 is directly inserted into the second connection groove 135. A second sealing ring 170 is provided between the end surface of the sheath 120 and the first step surface 134. When the insulator 110 is inserted into the inner wall of the flange cylinder 131 and abuts against the flange plate 132, the end surface of the sheath 120 directly presses against the second sealing ring 170, so that the second sealing ring 170 is fully compressed. At this time, the second sealing ring 170 abuts against the end surface of the sheath 120, the peripheral wall of the second connection groove 135, the outer wall of the insulator 110, and the first step surface 134 at the same time, which can fully seal the sheath 120 and the flange 130 and prevent external dirt, water vapor, etc. from entering the flange 130. At the same time, a sealing structure 160 is further coated in the cavity formed between the outer wall of the sheath 120 and the peripheral wall of the first connection groove 133. The sealing structure 160 extends and covers the outer periphery of the flange 130 and the outer periphery of the sheath 120. The material, structure, dimensions, etc. of the sealing structure 160 are the same as those described above and will not be elaborated.

[0032] In this embodiment, the second sealing ring 170 is disposed between the first step surface 134 and the end surface of the sheath 120, which can fully squeeze the second sealing ring 170 during the process of assembling the insulator 110 and the flange 130, so that the second sealing ring 170 is fully compressed, and then the sheath 120 and the flange 130 are fully sealed. At the same time, this method is applicable to the process of horizontally gluing the insulator 110 and the flange 130, avoiding the overflow of the glue between the contact surfaces of the insulator 110 and the flange 130. Otherwise, the overflowing glue will fill into the cavity between the flange 130 and the sheath 120, resulting in the sealing structure 160 being unable to be firmly coated.

[0033] Combined with Figure 4As shown, in another embodiment, a first connection groove 133 and a second connection groove 135 are provided on the inner wall of the flange cylinder 131. A sealing ring is provided between the sheath 120 and the flange 130. The sealing ring includes a first sealing ring 150 and a second sealing ring 170. The first sealing ring 150 is located between the outer wall of the sheath 120 and the peripheral wall of the first connection groove 133, and the second sealing ring 170 is located between the end face of the sheath 120 and the first step surface 134. Then, two seals are provided between the sheath 120 and the flange 130, which can better play a sealing role, and it is also applicable to the process of horizontally bonding the insulator 110 and the flange 130. The specific details are the same as those described above and will not be elaborated here.

[0034] The present application also provides a composite cross arm, which includes the aforementioned composite insulator 100. One end of the composite insulator 100 is connected to the tower body of the transmission tower, and the other end is used for hanging a conductor.

[0035] The beneficial effects of the present application are as follows: Different from the prior art, the composite insulator of the present application sets a high-performance sealing structure at the end face of the connection between the insulator and the flange, that is, in the form of encapsulation with high-temperature vulcanized silicone rubber. On the one hand, it effectively extends the sealing length of the sealing structure between the flange and the sheath, increases the safety distance for preventing water vapor from invading the inner wall of the flange, and maximally plays a sealing role; on the other hand, it ensures the consistency of the sealing structure material and the sheath material, thereby effectively improving the interface sealing effect and aging resistance of the sealing structure. At the same time, it can also shorten the preparation time, improve production efficiency, and improve the performance and quality of the finished product.

[0036] The technical content and technical features of the present application have been disclosed as above. However, it can be understood that under the creative concept of the present application, those skilled in the art can make various changes and improvements to the above structures and materials, including combinations of the technical features disclosed or claimed here alone, and obviously other combinations of these features. These deformations and / or combinations all fall within the technical field involved in the present application and within the protection scope of the claims of the present application.

Claims

1. A composite insulator, characterized in that: The composite insulator includes an insulator, a sheath wrapped around the outer circumference of the insulator, and flanges sleeved on both ends of the insulator, the flange includes a flange tube and a flange plate, the flange tube includes a first end and a second end arranged opposite to each other along its axial direction, the flange plate covers the first end of the flange tube, the end of the insulator is inserted into the inner wall of the flange tube from the second end of the flange tube and abuts the flange plate; the second end of the flange tube is provided with a connecting groove, the connecting groove extends radially outward on the inner wall of the flange tube along the radial direction of the flange tube, a first step surface is formed between the connecting groove and the inner wall of the flange tube, a sealing ring and a sealing structure are arranged in a cavity formed between the outer wall of the sheath and the peripheral wall of the connecting groove, and the sealing structure extends and covers the outer circumference of the flange and the outer circumference of the sheath.

2. The composite insulator according to claim 1, characterized in that: The sealing structure adopts high temperature vulcanized silicone rubber.

3. The composite insulator according to claim 2, characterized in that: The sheath is made of high temperature vulcanized silicone rubber, and the sealing structure has a smooth transition with the outer peripheral surface of the sheath.

4. The composite insulator according to claim 1, characterized in that: The sealing ring is located between the outer wall of the sheath and the peripheral wall of the connecting groove.

5. The composite insulator according to claim 1, characterized in that: The sealing ring is located between the end surface of the sleeve and the first step surface.

6. The composite insulator according to claim 1, characterized in that: The sealing ring includes a first sealing ring and a second sealing ring, wherein the first sealing ring is located between the outer wall of the sleeve and the peripheral wall of the connecting groove, and the second sealing ring is located between the end surface of the sleeve and the first step surface.

7. The composite insulator according to claim 1, characterized in that: In the axial direction of the composite insulator, the distance between the farthest position where the sealing structure extends to the outer circumference of the flange and the second end of the flange tube is 7 mm to 12 mm.

8. The composite insulator according to claim 1, characterized in that: In the axial direction of the composite insulator, the distance between the farthest position where the sealing structure extends to the outer periphery of the sheath and the second end of the flange tube is 12 mm to 15 mm.

9. The composite insulator according to claim 1, characterized in that: In the axial direction of the composite insulator, the sealing structure includes a first sealing area, a second sealing area and a third sealing area, the first sealing area is covered on the outer periphery of the flange, the second sealing area is covered on the outer periphery of the sheath, and the third sealing area is filled between the outer wall of the sheath and the peripheral wall of the connecting groove.

10. The composite insulator according to claim 9, characterized in that: The thickness of the first sealing area coated on the outer circumference of the flange is 3mm-5mm, and the thickness of the second sealing area coated on the outer circumference of the sleeve is equal to the sum of the thickness of the first sealing area and the radial distance from the outer wall of the sleeve to the outer wall of the flange.

11. A composite cross arm, characterized in that: It comprises the composite insulator as claimed in any one of claims 1 to 10.

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