Spiral insulating sheath

Abstract

The utility model provides a spiral insulating sheath, belonging to the insulating sheath technology field, the spiral insulating sheath comprises a sheath main body, the sheath main body is in a spiral structure, the cross section of the sheath main body is arc-shaped, the inner edge of the sheath main body is provided with a flanging part which is folded outwards, the cross section of the flanging part is trapezoid, and the outer edge of the sheath main body is provided with a plurality of grooves. A connecting bulge is arranged at one end of the sheath main body, a connecting groove matched with the connecting bulge is formed in the other end of the sheath main body, two end parts of the sheath main body are inwards shrunk in the radial direction to form a closing part, and a flanging part is continuously arranged along the full length of the inner edge of the sheath main body and extends from one end of the sheath main body to the other end of the sheath main body; the sheath comprises a sheath main body, the sheath main body is provided with closing-up portions, the closing-up portions are located at the two ends of the sheath main body, the outer surface of the sheath main body is provided with annular grooves, and the annular grooves are arranged at equal intervals in the axial direction of the sheath main body, and the problems that a traditional insulating sheath is insufficient in fitting degree with a wire and poor in universality, and the insulating performance is reduced are solved.

Description

Technical Field

[0001] This utility model belongs to the field of insulating sleeve technology, specifically, it relates to a spiral insulating sleeve. Background Technology

[0002] With the continuous development of power systems, overhead transmission lines, as a crucial infrastructure for power transmission, are of paramount importance for their safe and stable operation. Overhead conductors operate in various complex natural environments, facing numerous challenges such as dust, humidity, lightning, and strong winds. These factors can lead to problems like line discharge and flashover, thereby affecting the reliability and safety of power transmission. Insulating sheaths, as a protective device for overhead conductors, have emerged to address this need. Primarily made of insulating material, they are wrapped around the surface of the overhead conductors to provide additional insulation protection and reduce electrical faults caused by external environmental factors. Their installation is relatively simple, requiring no large-scale modifications to the existing transmission line structure, and can improve the insulation level of the line to a certain extent, enhancing its ability to withstand harsh environments.

[0003] Traditional insulating sheaths have several drawbacks. Structurally, traditional sheaths are often quite simple, lacking refined design in shape and construction. This conventional shape results in insufficient fit with the conductor, making it prone to gaps between the sheath and conductor during long-term operation due to vibration, wind sway, and other factors. This allows dust, moisture, and other impurities to infiltrate, reducing insulation performance. Furthermore, traditional insulating sheaths have poor versatility; a single sheath specification is often only suitable for a specific type of overhead conductor. In actual transmission line projects, there are numerous conductor specifications, meaning a large stock of different sheath specifications is required. This not only increases the difficulty and cost of inventory management but also risks failing to achieve adequate protection due to the selection of the wrong sheath specification, increasing the risk of line faults. Additionally, traditional sheaths have sealing defects. Inadequate sealing at connection points or contact points with the conductor allows moisture and humidity to enter the sheath, triggering partial discharge under the influence of the electric field. This accelerates the aging and damage of the sheath, shortens its service life, and ultimately affects the reliability of the transmission line. Utility Model Content

[0004] In view of this, the present invention provides a spiral insulating sheath that solves the shortcomings of traditional insulating sheaths in terms of fit with the conductor and poor versatility, which leads to reduced insulation performance.

[0005] This utility model is implemented as follows:

[0006] This utility model provides a spiral insulating sheath, including a sheath body. The sheath body has a spiral structure with an arc-shaped cross-section. The inner edge of the sheath body has an outwardly folded flange with a trapezoidal cross-section. One end of the sheath body is provided with a connecting protrusion, and the other end is provided with a connecting groove that matches the connecting protrusion. Both ends of the sheath body taper inward in the radial direction to form a constricted opening.

[0007] The flanged portion is continuously installed along the entire inner length of the sheath body, extending from one end to the other. The flanged portion is integrally formed with the sheath body. Near the inner edge of the sheath body, the flanged portion begins to fold outwards with a smooth transition, gradually increasing in angle until it reaches a trapezoidal shape. The upper base of the trapezoid faces inwards from the sheath body, and the lower base faces outwards. The hypotenuse between the upper and lower bases forms a certain angle with the axial direction of the sheath body. This angle ensures that the flanged portion can better conform to the wire during installation and form a stable connection structure after applying adhesive or wrapping with silicone self-adhesive tape. Simultaneously, it can evenly distribute stress under load, avoiding connection failure or sheath damage caused by localized stress concentration.

[0008] Based on the above technical solution, the spiral insulating sleeve of this utility model can be further improved as follows:

[0009] The central angle of the arc is between 90° and 180°.

[0010] Furthermore, the width of the upper base of the trapezoid is smaller than the width of the lower base.

[0011] Furthermore, the outer surface of the sheath body has an annular groove, which is equidistantly arranged along the axial direction of the sheath body, and the depth of the annular groove is less than the thickness of the sheath body.

[0012] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the annular grooves are evenly distributed on the outer surface of the sheath body and are equidistantly arranged along the axial direction of the sheath body. During operation, when rainwater or dust adheres to the surface of the sheath, the annular grooves can guide the water flow and prevent dust accumulation, reducing the risk of electrical performance degradation and flashover caused by water film or dust accumulation. At the same time, when the sheath expands due to heat or contracts due to cold, the annular grooves can also provide a certain deformation space to alleviate internal stress.

[0013] Furthermore, the cross-sectional shape of the connecting protrusion is semi-circular.

[0014] The connecting protrusion is located on the outer surface of one end of the sheath body, and is a ring-shaped protrusion along the circumferential direction.

[0015] Furthermore, the inner side of the sheath body is provided with reinforcing ribs along the spiral direction. The cross-sectional shape of the reinforcing ribs is rectangular, and the angle between the reinforcing ribs and the inner wall of the sheath body is between 0° and 90°.

[0016] Furthermore, the outer surface of the sheath body is provided with a number of anti-slip protrusions at intervals along the spiral direction, and the anti-slip protrusions are hemispherical.

[0017] Furthermore, the tapered portion has a contraction angle, which is between 0° and 90°.

[0018] The tapered ends are located at both ends of the sheath body. Starting from the normal spiral diameter of the sheath body, the tapering gradually narrows inwards within a certain length range at the ends (e.g., 1 / 3 to 1 / 2 of the end length). The tapering process follows a uniform curve, and the tapering angle creates a gradually narrowing opening at the ends. This tapered design allows for easy installation of the sheath over overhead conductors and effectively prevents dust, moisture, and other impurities from entering the sheath from the ends during operation. It also reduces the risk of partial discharge at the sheath ends due to airflow and other factors, thus improving the overall protective performance of the sheath.

[0019] Furthermore, the outer surface of the sheath body is provided with several guide grooves along the circumference, and the guide grooves extend from one end of the sheath body to the other end in a straight line.

[0020] The drainage channels are distributed circumferentially on the outer surface of the sheath body. The bottom of the drainage channels is narrower and the top opening is slightly wider. This shape design helps to quickly guide rainwater to both ends of the sheath in rainy weather, preventing rainwater from forming a large water film on the sheath surface and reducing insulation performance. At the same time, in strong winds, it also allows airflow to flow along the drainage channels, reducing vibration and noise caused by airflow impact and improving the stability of the sheath in harsh environments.

[0021] Furthermore, the sheath body is made of high-temperature vulcanized silicone rubber material.

[0022] High-temperature vulcanized solid silicone (HTV), as the name suggests, is silicone that solidifies upon heating. It is commonly used to manufacture elastic, high-temperature resistant products such as seals, gaskets, and wire insulation. This material undergoes a vulcanization reaction at high temperatures, forming a soft yet heat-resistant silicone structure suitable for various special environments and applications. In the manufacturing process of solid silicone (HTV), the silicone is heated to a high temperature, and a vulcanizing agent is added to promote the vulcanization reaction. This vulcanization process causes cross-linking between silicone molecules, enhancing the material's elasticity and heat resistance. HTV is frequently chosen for manufacturing products requiring high-temperature resistance, good elasticity, and insulation properties.

[0023] Compared with the prior art, the beneficial effects of the spiral insulating sheath provided by this utility model are:

[0024] This utility model features a unique spiral insulating sheath structure. Its spiral shape and arc-shaped cross-section allow it to better conform to the circular cross-section of overhead conductors, increasing the contact area and thus enhancing the friction and gripping force between the sheath and the conductor, effectively preventing slippage or displacement of the sheath on the conductor surface. During installation, the arc-shaped structure makes it easier to wind the sheath along the shape of the conductor, reducing resistance and difficulty. Simultaneously, the inner edge of the sheath body has an outward-folded flange. This flange not only increases the stability of the connection between the sheath and the conductor but also allows for easy installation by using specialized tools to fold the flange outwards and apply adhesive or wrap it with silicone rubber self-adhesive tape. This installation method is convenient and allows for quick and tight connection between the sheath and the conductor. Furthermore, during disassembly, simply breaking the adhesive or self-adhesive tape allows for easy removal of the sheath without damaging the conductor or other accessories, greatly improving the convenience and efficiency of installation and disassembly, and reducing the workload and cost of line maintenance.

[0025] The unique shape and position of the connecting protrusion at one end and the connecting groove at the other end of the sheath body allow multiple sheaths to be connected end-to-end. The semi-circular cross-section of the connecting protrusion and the fitting shape of the connecting groove ensure a good fit during connection, guaranteeing tightness and stability. This connection method not only facilitates the splicing and combination of sheaths to meet different length requirements and adapts to overhead conductor straight-line towers of various lengths, but also maintains the continuity of the overall structure of the sheath after connection, avoiding electrical performance degradation or protection failure due to defects in the connection points, further enhancing the versatility and practicality of the sheath.

[0026] The sheath body is made of high-temperature vulcanized silicone rubber, a material with excellent electrical insulation properties, corona resistance, corrosion resistance, and aging resistance. During operation, it effectively resists the erosion of external electric fields, chemicals, and ultraviolet radiation, preventing discharge and flashover on the sheath surface. Even under prolonged operation and harsh environmental conditions, it maintains good insulation performance, providing continuous and stable insulation protection for overhead conductors. This reduces the probability of tripping and power outages caused by insulation problems, greatly improving the reliability and safety of transmission lines. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 Here is an example diagram of a spiral insulating sheath;

[0029] Figure 2 A top view of a spiral insulating sheath;

[0030] Figure 3 A cross-sectional view of a spiral insulating sheath;

[0031] The attached diagram lists the components represented by each number as follows:

[0032] 10. Sheath body; 11. Annular groove; 20. Flanged edge; 30. Closure. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0034] like Figures 1-3 The image shows a first embodiment of a spiral insulating sheath provided by this utility model. In this embodiment, it includes a sheath body 10, which has a spiral structure and an arc-shaped cross-section. The inner edge of the sheath body 10 has an outwardly folded flange 20, which has a trapezoidal cross-section. One end of the sheath body 10 is provided with a connecting protrusion, and the other end is provided with a connecting groove that matches the connecting protrusion. The two ends of the sheath body 10 taper inward in the radial direction to form a constricted opening 30.

[0035] The upper base of the trapezoid is connected to the inner edge of the sheath body. From this upper base, two inclined sides extend outwards, eventually converging at the lower base. This structure allows the flanged part to be decomposed and transmitted through the inclined sides when subjected to inward forces (such as the sheath's own contraction force or external environmental pressure) after it is turned outwards. The force is ultimately applied to the contact surface between the lower base and the conductor, allowing the flanged part to fit more tightly against the conductor, enhancing the stability of the connection. It also helps to better prevent dust, moisture, and other impurities from entering.

[0036] In the above technical solution, the central angle of the arc is between 90° and 180°.

[0037] Furthermore, in the above technical solution, the width of the upper base of the trapezoid is smaller than the width of the lower base.

[0038] Furthermore, in the above technical solution, the outer surface of the sheath body 10 has an annular groove 11, the annular groove 11 is arranged at equal intervals along the axial direction of the sheath body 10, and the depth of the annular groove 11 is less than the thickness of the sheath body 10.

[0039] Furthermore, in the above technical solution, the cross-sectional shape of the connecting protrusion is semi-circular.

[0040] The connecting groove is located on the inner surface of the other end of the sheath body. Its shape matches the semi-circular shape of the connecting protrusion, and its depth is slightly greater than the radius of the connecting protrusion. The inner wall of the groove is smooth, which allows the connecting protrusion to be smoothly embedded in it during connection. After embedding, the two are tightly joined by squeezing or other connection methods (such as applying adhesive), realizing the end-to-end connection between multiple sheaths to meet the protection requirements of overhead conductors of different lengths and ensure the continuity and sealing of the overall structure of the sheath after connection.

[0041] Furthermore, in the above technical solution, the inner side of the sheath body 10 is provided with reinforcing ribs along the spiral direction. The cross-sectional shape of the reinforcing ribs is rectangular, and the angle between the reinforcing ribs and the inner wall of the sheath body 10 is between 0° and 90°.

[0042] Furthermore, in the above technical solution, the outer surface of the sheath body 10 is provided with a number of anti-slip protrusions at intervals along the spiral direction, and the anti-slip protrusions are hemispherical.

[0043] Furthermore, in the above technical solution, the closing part 30 has a shrinkage angle, which is between 0° and 90°.

[0044] Furthermore, in the above technical solution, the outer surface of the sheath body 10 is provided with several guide grooves along the circumference. The guide grooves extend from one end of the sheath body 10 to the other end in a straight line.

[0045] The guide channels and annular grooves intersect. When rainwater falls on the sheath surface, the annular grooves first collect and disperse the rainwater, ensuring its uniform distribution circumferentially. The rainwater then flows rapidly along the guide channels to both ends of the sheath for discharge. This intersecting design allows the sheath to operate efficiently in handling water flow from different directions. It can handle water accumulation in the vertical direction and cope with the scouring of water in the horizontal direction, synergistically enhancing the sheath's waterproof, anti-fouling, and environmental interference resistance capabilities, ensuring the stable operation of the transmission line.

[0046] Furthermore, in the above technical solution, the sheath body 10 is made of high-temperature vulcanized silicone rubber material.

[0047] Specifically, the principle of this utility model is as follows:

[0048] The principle of spiral structure and arc cross-section:

[0049] The spiral structure is designed based on the linear characteristics of overhead conductors. Through spiral winding, the sheath can fully cover the conductor along its length, providing all-around protection. The arc-shaped cross-section is optimized based on the circular cross-sectional shape of the conductor. Mathematically, the arc shape has better fit than the circle, allowing for surface contact between the sheath and the conductor rather than point or line contact. According to mechanical principles, surface contact can evenly distribute pressure. When the sheath is subjected to external forces (such as wind or gravity), the pressure can be evenly distributed on the conductor surface, reducing local stress concentration. For example, under wind loads, the arc-shaped sheath can better conform to the wind direction, evenly transmitting the pressure generated by the wind along the circumference of the conductor, preventing separation of the sheath from the conductor or damage to the sheath itself due to excessive local pressure. Simultaneously, from a physical performance perspective, the arc structure increases the flexibility of the sheath, allowing it to better adapt to deformation when the conductor undergoes minor bending or vibration, without rigid fracture or damage, ensuring the structural integrity of the sheath during long-term operation.

[0050] The principle behind the flange, connecting protrusion, and connecting groove:

[0051] The design principle of the flanged section is primarily to enhance the reliability of the connection between the sheath and the conductor. During installation, the flanged section is folded outwards and bonded, forming a "locking" structure from a mechanical perspective. When subjected to inward forces (such as the sheath's own contraction force or external environmental pressure), the outward-folded flanged section adheres more tightly to the conductor. Furthermore, due to the special trapezoidal structure between the flanged section and the sheath body, the force is distributed and transmitted along the hypotenuse of the trapezoid, making the connection more stable. From a materials science perspective, this flanged structure increases the bonding area, improving the adhesion between the adhesive or silicone self-adhesive tape and the sheath and conductor, thereby enhancing the sealing and durability of the connection.

[0052] The design of the connecting protrusion and groove is based on the principle of stability in mechanical connections. The semi-circular connecting protrusion and its matching groove form a good geometric fit during connection. From a mechanical perspective, when subjected to tension or pressure, friction and mutual supporting forces are generated on the contact surface between the connecting protrusion and groove. According to the friction formula f = μN (where f is the friction force, μ is the coefficient of friction, and N is the normal force), the tight fit between the connecting protrusion and groove increases the normal force N, thereby improving the friction at the connection point and preventing loosening. Simultaneously, when transmitting axial forces (such as the tension of a conductor or the axial component of wind force), this connection method can evenly transfer the force to adjacent sheath sections through the contact surface between the protrusion and groove, ensuring the mechanical stability of the entire sheath structure in the axial direction.

Claims

1. A helical insulating jacket comprising a jacket body (10), characterised in that, The sheath body (10) is in a spiral structure, the cross-sectional shape is arc, the inner edge of the sheath body (10) has a outwardly folded flange (20), the cross-sectional shape of the flange (20) is trapezoidal, one end of the sheath body (10) is provided with a connecting protrusion, the other end is provided with a connecting groove matched with the connecting protrusion, the two ends of the sheath body (10) are inwardly contracted in the radial direction to form a contracted portion (30).

2. A helical insulating jacket according to claim 1, wherein The central angle of the arc is 90° to 180°.

3. A helical insulating jacket according to claim 2, wherein, The upper base width of the trapezoid is less than the lower base width.

4. A helical insulating jacket according to claim 3, wherein, The outer surface of the sheath body (10) has an annular groove (11), the annular grooves (11) are equidistantly arranged along the axial direction of the sheath body (10), the depth of the annular groove (11) is less than the thickness of the sheath body (10).

5. A helical insulating jacket according to claim 4, wherein, The cross-sectional shape of the connecting protrusion is semicircular.

6. A helical insulating jacket according to claim 5, wherein, The sheath body (10) is provided with a reinforcing rib inside in the spiral direction, the cross-sectional shape of the reinforcing rib is rectangular, the included angle between the reinforcing rib and the inner wall of the sheath body (10) is 0° to 90°.

7. A helical insulating jacket according to claim 6, wherein, The outer surface of the sheath body (10) is provided with several anti-skid protrusions in the spiral direction, the anti-skid protrusions are semispherical.

8. A helical insulating jacket according to claim 7, wherein, The contracted portion (30) has a contraction angle, the contraction angle is 0° to 90°.

9. A helical insulating jacket according to claim 8, wherein, The outer surface of the sheath body (10) is provided with several guide grooves in the circumferential direction, the guide grooves extend from one end to the other end of the sheath body (10) in a straight line.

10. A helical insulating jacket according to claim 9, wherein, The sheath body (10) is made of high temperature vulcanized silicone rubber material.

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