Wall bushing

Abstract

The present invention discloses a wall bushing, comprising a head assembly, a conductive rod, a protective bellows, and a terminal block; the head assembly is provided with a receiving cavity, the upper end portion and the lower end portion of the head assembly are respectively coaxially provided with a first through hole and a second through hole communicating with the receiving cavity, the protective bellows is an annular shell that passes through from top to bottom, the protective bellows is respectively provided with an upper through hole and a lower through hole, the conductive rod passes through the first through hole, the second through hole, the upper through hole, and the lower through hole, the lower through hole is fixedly connected to the conductive rod, the terminal block is electrically connected to the conductive rod and a sealing cover is provided with the head assembly and the conductive rod. The wall bushing has a simple structure, the head assembly replaces the traditional bellows structure, and the use of an axial dynamic sealing device can be avoided, thereby greatly improving the sealing reliability of the product and reducing the production cost; the provision of the protective bellows further prevents possible metal chips or other debris from entering the main insulating cavity of the wall bushing, thereby improving the operational reliability of the product.

Description

Technical Field

[0001] The present application relates to the technical field of power transmission insulation equipment, and in particular to a wall bushing. Background Art

[0002] In DC transmission and transformation projects, the wall bushing, as the only electrical component connecting the inside and outside of the valve hall, carries the full voltage and current of the entire line. Its performance reliability is related to the operational safety and stability of the entire line.

[0003] At present, the head components of existing wall bushings are mostly bellows, and the conductive rod and the bellows are axially sealed. The conductive rod passes through the bellows and is directly electrically connected to the external components. Specifically, one end of the conductive rod is fixed to the end of the wall bushing, and the other end of the conductive rod is fixed to the bellows and extends out of the bellows to be electrically connected to the external components. The elastic bellows provides tension to the conductive rod to maintain the tension of the conductive rod. When the conductive rod is heated and elongated, the bellows can undergo elastic deformation, so that the conductive rod remains straight and no stress bending occurs. However, there are the following problems: when the head component of the wall bushing adopts a bellows, if axial sealing is adopted, due to the friction effect of long-term thermal expansion and contraction, the long-term reliability of its dynamic seal cannot be guaranteed, and the product is prone to air leakage; if axial sealing is not adopted, an external transition tank needs to be installed, and a soft connection needs to be used between the terminal and the conductive rod, which limits the flow capacity; and the bellows itself is relatively expensive, which increases the manufacturing cost of the product; metal chips are easily generated due to friction between the conductive rod and the head component, resulting in internal discharge. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a wall bushing with a simple structure. The head assembly replaces the traditional bellows structure, which can avoid the use of an axial dynamic sealing device, greatly improve the sealing reliability of the product, and reduce production costs. The provision of a protective bellows further prevents possible metal chips or other debris from entering the main insulating cavity of the wall bushing, thereby improving the operational reliability of the product.

[0005] To achieve the above-mentioned purpose, the technical means adopted by the present invention are as follows: a wall bushing, comprising a head assembly, a conductive rod, a protective bellows and a terminal; the head assembly is provided with a receiving cavity, the upper end and the lower end of the head assembly are respectively coaxially provided with a first through hole and a second through hole communicating with the receiving cavity, the protective bellows is an annular shell extending vertically, the protective bellows is respectively provided with an upper through hole and a lower through hole, the conductive rod passes through the first through hole, the second through hole, the upper through hole and the lower through hole, the protective bellows is provided with an upper connecting end around the upper through hole, the upper connecting end is fixedly connected to the lower end of the head assembly around the second through hole, the lower through hole is fixedly connected to the conductive rod, the terminal is electrically connected to the conductive rod and a sealing cover is provided with the head assembly and the conductive rod. The wall bushing has a simple structure, the head assembly replaces the traditional bellows structure, and can avoid the use of an axial dynamic sealing device, greatly improving the sealing reliability of the product and reducing the production cost; the provision of the protective bellows further prevents possible metal chips or other debris from entering the main insulating cavity of the wall bushing, thereby improving the operational reliability of the product.

[0006] Preferably, the upper connecting end is a flange extending radially along the upper through hole, and the flange is attached to and fixedly connected to the lower end of the head assembly. The flange and the head assembly adopt a disc-type plane connection, which is easy to install and has a reliable structure.

[0007] Preferably, a mounting hole is provided in the flange, with a channel connecting the mounting hole and the upper through-hole. The filter element is installed in the mounting hole, and the filter element only allows gas exchange between the interior and exterior of the protective bellows. During inflation and deflation, the wall bushing only allows gas to pass through, preventing impurities and metal shavings from entering the main insulating cavity through the filter element.

[0008] Preferably, the filter element is a metal mesh structure. For example, a titanium rod filter element is a porous filter element made from industrial high-purity titanium. After screening, cooling, isostatic pressing, and high-temperature high-vacuum sintering, it has excellent properties such as corrosion resistance, high temperature resistance, high strength, easy to ensure filtration accuracy, and easy regeneration.

[0009] Preferably, the diameter of the lower through hole is smaller than the minimum inner diameter of the protective bellows, a lower connecting end is provided around the lower through hole, a first round nut and a second round nut are provided on either side of the lower connecting end, and the first round nut and the second round nut are respectively connected to the conductive rod through threaded connection to clamp the lower connecting end so that the protective bellows and the conductive rod are fixedly connected. On the one hand, the fixed connection between the protective bellows and the conductive rod eliminates a gap between the protective bellows and the conductive rod, ensuring that impurities and metal chips in the protective bellows do not enter the insulating main cavity; on the other hand, the conductive rod deforms due to thermal expansion and contraction, and the protective bellows has a certain amount of elastic deformation space, and its size will change accordingly with the deformation of the conductive rod, ensuring a stable connection between the various components of the wall bushing.

[0010] Preferably, the head assembly includes a transition tank and a transition plate connected to each other; a first through-hole is provided at the upper end of the transition tank, and a through-hole extends through the lower end of the transition tank; a second through-hole is provided at the transition plate, and the transition tank and the transition plate are fixedly connected to form a receiving cavity within the transition tank surrounding the conductive rod. The transition tank is a rigid component that replaces the traditional bellows structure, eliminating the need for an axial dynamic seal, significantly improving product sealing reliability, and reducing production costs.

[0011] Preferably, a plurality of annular grooves are provided on the circumferential inner wall of the transition tank, which act as particle traps to absorb metal particles in the transition tank and ensure stable electrical performance of the head of the wall bushing.

[0012] Preferably, a threaded hole is provided on the side of the flange that contacts the transition plate, and a through hole corresponding to the threaded hole is provided on the transition plate, and the flange and the transition plate are threadedly connected by bolts. This connection structure is more convenient for assembling the wall bushing.

[0013] Preferably, a convex ring is provided on the upper surface of the transition plate around the second through hole, and the convex ring is located in the accommodating cavity. The provision of the convex ring increases the supporting area for the conductive rod and can improve the bending resistance of the conductive rod.

[0014] Preferably, a non-metallic lining is provided on the inner wall of the first through hole and / or the inner wall of the second through hole and / or the inner wall of the convex ring. The non-metallic lining prevents metal chips from being generated by friction between the conductive rod and the transition plate and the transition tank, thereby improving the operational reliability of the product.

[0015] Preferably, the inner wall of the raised ring is provided with a plurality of grooves, into which the non-metallic liner is embedded. This structure allows the non-metallic liner to be embedded in the grooves in a broken-ring manner. This reduces the amount of non-metallic liner used, thus lowering production costs. Furthermore, the broken-ring non-metallic liner embedded in the inner wall of the grooves is easier to install and secure than a larger non-metallic liner installed as a single piece on the inner wall of the raised ring. During use, the non-metallic liner will not shift on the inner wall of the raised ring.

[0016] Preferably, the terminal block comprises, in sequence, a wiring portion, a receiving portion, and a connecting portion. The receiving portion is used to accommodate the end of the conductive rod and electrically connect to the conductive rod, and the connecting portion is sealed to the upper end of the head assembly. The terminal block is an electrical connection component for a wall bushing and is used to electrically connect to other equipment. The connection portion facilitates the secure connection between the terminal block and the transition tank.

[0017] Preferably, a spring contact finger is provided at the end of the conductive rod, abutting the inner wall of the housing. A gap exists between the housing and the end of the conductive rod along the axial direction of the conductive rod. The spring contact finger is in close contact with both the terminal block and the end of the conductive rod, ensuring a stable electrical connection between the terminal block and the end of the conductive rod, maintaining equal potential between the head assembly and addressing head heating issues. The gap between the housing and the end of the conductive rod along the axial direction of the conductive rod absorbs deformation of the conductive rod due to thermal expansion and contraction, preventing the conductive rod from bending due to the fixed connection.

[0018] Preferably, the wall bushing further comprises a hollow insulator, the hollow insulator is sealedly connected to the transition plate, and the conductive rod passes through the hollow insulator. The hollow insulator provides insulation protection for the internal conductor of the wall bushing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a partial cross-sectional view of a wall bushing 100 according to a first embodiment of the present invention;

[0020] Figure 2 is a three-dimensional schematic diagram of the protective bellows 150 according to the first embodiment of the present invention;

[0021] Figure 3 is a cross-sectional view of the filter element 160 according to the first embodiment of the present invention;

[0022] Figure 4 is a partial cross-sectional view of a wall bushing 200 according to a second embodiment of the present invention;

[0023] Figure 5 is a partial cross-sectional view of a wall bushing 300 according to a third embodiment of the present invention;

[0024] Figure 6 is a cross-sectional view of the connection terminal 340 according to the third embodiment of the present invention;

[0025] Figure 7 is a partial cross-sectional view of a wall bushing 400 according to a fourth embodiment of the present invention;

[0026] Figure 8 It is an overall cross-sectional view of the wall sleeve 400 according to the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0027] Upon request, specific embodiments of the present invention will be disclosed herein. However, it should be understood that the embodiments disclosed herein are merely exemplary of the present invention, which may be embodied in various forms. Therefore, the specific details disclosed herein are not to be construed as limiting, but merely as a basis for the claims and as a representative basis for teaching those skilled in the art to variously apply the present invention in any appropriate manner, including employing the various features disclosed herein in combination with features that may not be explicitly disclosed herein.

[0028] Example 1:

[0029] like Figure 1-3 As shown, this embodiment provides a wall bushing 100, including a head assembly 110, a conductive rod 120, a protective bellows 150 and a terminal 140; the head assembly 110 is provided with a receiving cavity 113, the upper end and the lower end of the head assembly 110 are respectively coaxially provided with a first through hole 1111 and a second through hole 1121 communicating with the receiving cavity 113, the protective bellows 150 is an annular shell that passes through the upper and lower parts, and the protective bellows 150 is respectively provided with an upper through hole 151 and a lower through hole 1121. The conductive rod 120 passes through the first through hole 1111, the second through hole 1121, the upper through hole 151, and the lower through hole 152. The protective bellows 150 is provided with an upper connecting end 153 around the upper through hole 151. The upper connecting end 153 is fixedly connected to the lower end of the head assembly 110 around the second through hole 1121. The lower through hole 152 is fixedly connected to the conductive rod 120. The terminal block 140 is electrically connected to the conductive rod 120 and seals the head assembly 110 and the conductive rod 120. The wall bushing 100 has a simple structure. The head assembly 110 replaces the traditional bellows structure, which can avoid the use of an axial dynamic sealing device, greatly improving the product's sealing reliability and reducing production costs. The provision of the protective bellows 150 further prevents possible metal chips or other debris from entering the main insulating cavity of the wall bushing 100, improving the product's operational reliability.

[0030] It should be noted that in this embodiment, the upper and lower ends of the head assembly 110 are relative positions. Along the axis of the overall structure of the wall sleeve 100, the end closest to the head assembly 110 is considered upper, and the end farther from the head assembly 110 is considered lower. In other embodiments, the definitions of "upper" and "lower" also follow this standard.

[0031] In this embodiment, the protective bellows 150 is a circular ring shell. In other embodiments, the shape of the annular shell of the protective bellows can also be set to other shapes, such as a square ring, an elliptical ring, etc., and is not limited to a circular ring.

[0032] In this embodiment, the upper connecting end 153 is a flange 153 extending radially outward from the upper through hole 151. The flange 153 is attached to and fixedly connected to the lower end of the head assembly 110. The flange 153 and the head assembly 110 are connected in a disk-type planar manner, which is easy to install and has a reliable structure.

[0033] In other embodiments, the structure of the upper connecting end is not limited thereto, for example, it may be a circular ring structure or a sawtooth structure extending along the upper through hole, and a matching groove is provided at the lower end of the head assembly for plugging in, assisted by adhesive fixation.

[0034] In this embodiment, a mounting hole 1531 is provided in flange 153. A channel 1532 is provided between mounting hole 1531 and upper through hole 151. Filter element 160 is installed in mounting hole 1531. Filter element 160 only allows gas exchange between the interior and exterior of protective bellows 150. During the inflation and deflation process of wall bushing 100, filter element 160 only allows gas to pass through, preventing internal impurities and metal shavings from entering the insulating main cavity through filter element 160.

[0035] In this embodiment, the number of mounting holes 1531 is 3, and the number of corresponding filter elements 160 is also 3. In other embodiments, the number of mounting holes and filter elements can be equal, and the specific number and distance between different mounting holes are not specifically limited.

[0036] In this embodiment, the mounting hole 1531 is a through hole, and the channel 1532 is provided on the surface of the flange 153 and is a linear groove connecting the mounting hole 1531 and the upper through hole 151. The channel 1532 is a channel for gas exchange between the inside and outside of the protective bellows 150.

[0037] In other embodiments, the mounting hole is not a through hole, and a channel is provided between the bottom end of the mounting hole and the upper through hole. The channel is disposed inside the flange and cannot be observed from the surface of the flange. In short, the shape and location of the channel are not limited, as long as the purpose of gas exchange between the interior and exterior of the protective bellows is achieved.

[0038] In this embodiment, the filter element 160 includes a filter portion 161 and a filter element connection portion 162. The filter portion 161 is a cylindrical metal sintered mesh. The side surface 1611 and top surface 1612 of the filter portion 161 are integrally designed and seamlessly connected. A through hole 1614 is provided on the bottom surface 1613 of the filter portion 161, and the filter element connection portion 162 is provided around the through hole 1614. The filter element connection portion 162 is a cylindrical structure that runs vertically through, with one end connected to the through hole 1614 and the other end being an outlet. The filter element connection portion 162 is provided with threads 1621. The mounting hole 1531 is provided with threads that mate with the threads 1621. When the filter element connection portion 162 is installed in the mounting hole 1531, the exposed portion of the filter element 160 is integrally designed and seamlessly connected.

[0039] In this embodiment, the filter element 160 is a titanium rod filter element 160 with a metal mesh structure. The titanium rod filter element 160 is a porous filter element made of industrial high-purity titanium as raw material, which is screened, cooled and statically pressed, and then sintered at high temperature and high vacuum. It has excellent properties such as corrosion resistance, high temperature resistance, high strength, easy to ensure filtering accuracy, and easy regeneration.

[0040] In this embodiment, the titanium rod filter element 160 has the following product features: uniform structure, narrow pore size distribution, and high separation efficiency; high porosity, small filtration resistance, and high permeation efficiency; high temperature resistance, generally can be used normally below 280°C; good chemical stability, acid and alkali corrosion resistance, and antioxidant properties; no particle shedding; good mechanical properties and simple operation.

[0041] In other embodiments, the filter element may also be made of other sintered mesh materials that are corrosion-resistant, high-temperature resistant, strong, and easy to ensure filtering accuracy, such as polytetrafluoroethylene, stainless steel, and other materials.

[0042] In this embodiment, the diameter of the lower through hole 152 is smaller than the minimum inner diameter of the protective bellows 150. A lower connecting end 154 is disposed around the lower through hole 152. A first round nut 156 and a second round nut 157 are disposed on either side of the lower connecting end 154. The first round nut 156 and the second round nut 157 are respectively threadedly connected to the conductive rod 120 to clamp the lower connecting end 154, thereby securely connecting the protective bellows 150 to the conductive rod 120. The secure connection between the protective bellows 150 and the conductive rod 120 not only eliminates a gap between the protective bellows 150 and the conductive rod 120, but also prevents impurities and metal chips in the protective bellows 150 from entering the insulating main cavity. Furthermore, as the conductive rod 120 deforms due to thermal expansion and contraction, the protective bellows 150 has a certain amount of elastic deformation space, and its dimensions change accordingly with the deformation of the conductive rod 120, thereby ensuring a stable connection between the various components of the wall bushing 100.

[0043] In other embodiments, the protective bellows and the conductive rod may be fixedly connected by welding, gluing, or other fixed connection methods, and the fixed connection between the two does not require sealing.

[0044] In this embodiment, the protective bellows 150 is made of metal. The metal protective bellows 150 can also play a certain shielding role and improve the operational reliability of the product.

[0045] In other embodiments, the protective bellows may also be made of non-metallic material, as long as it can ensure that no metal chips are generated between the protective cover and the conductive rod due to secondary friction.

[0046] It can be understood that in this embodiment, due to the provision of the protective bellows 150, a cavity is formed by the protective bellows 150, the conductive rod 120, the transition plate 112 and the filter element 160, which only allows gas exchange. There is no gap between the protective bellows 150 and the conductive rod 120, and only gas is allowed to pass through under unsealed conditions; a channel 1532 and a filter element 160 are provided between the protective bellows 150 and the transition plate 112. The metal particles inside the protective bellows 150 will be blocked by the filter element 160 and cannot migrate to the outside of the protective bellows 150. In this structure, there are no other outlets and inlets, which can ensure that the metal particles inside the protective bellows 150 will not enter the main insulating cavity of the wall bushing 100 during the inflation and deflation process, thereby ensuring the reliability of the operation of the wall bushing 100. Moreover, since the protective bellows 150 and the conductive rod 120 are fixedly connected and no displacement will occur between the two, when the conductive rod 120 is deformed due to thermal expansion and contraction, the size of the protective bellows 150 also changes accordingly to ensure that the conductive rod 120 does not bend or the transition plate 112 is deformed. Therefore, the protective bellows 150 is mainly used to utilize its own elastic deformation to provide space for the conductive rod 120 to deform.

[0047] In this embodiment, the head assembly 110 includes a transition tank 111 and a transition plate 112 that are interconnected; a first through hole 1111 is provided at the upper end of the transition tank 111, and the lower end of the transition tank 111 is through-hole; a second through hole 1121 is provided at the transition plate 112, and the conductive rod 120 passes through the first through hole 1111 and the second through hole 1121. The transition tank 111 and the transition plate 112 are fixedly connected so that a receiving cavity 113 is formed in the transition tank 111 around the conductive rod 120. The wall bushing 100 has a simple structure, and its core components are the transition tank 111 and the transition plate 112. The setting of the transition tank 111 replaces the structure of the traditional bellows. As long as the sealing setting of the transition tank 111 can be guaranteed, that is, sealing measures are applied to the outside of the transition tank 111, the use of an axial dynamic sealing device between the transition tank 111 and the conductive rod 120 can be avoided, which greatly improves the sealing reliability of the product and reduces the production cost. It is particularly noteworthy that the sealing cover is provided with a terminal 140 for the head assembly 110 and the conductive rod 120. As long as the electrical connection with the conductive rod 120 is met, the electrical connection can be in the form of direct contact or internal conductor connection. There is no specific restriction on the shape and structure of the terminal 140.

[0048] In other embodiments, the head assembly can be an integrally formed cavity structure, as long as it meets the requirements of a rigid component, that is, it will not deform or move under the interference of external thermal conditions. This ensures that the head assembly will not deform or move due to changes in the length of the conductive rod, thereby maintaining the stability of the overall structure of the wall bushing.

[0049] In this embodiment, a convex ring 1123 is provided on the upper surface of the transition plate 112 around the second through hole 1121. The provision of the convex ring 1123 increases the supporting area for the conductive rod 120 and can improve the bending resistance of the conductive rod 120.

[0050] In this embodiment, the protruding ring 1123 is disposed within the accommodating cavity 113 of the head assembly 110, and its height does not exceed the height of the transition tank 111. Specifically, a gap exists between the upper end surface of the protruding ring 1123 and the inner wall of the transition tank 111, but the protruding ring 1123 does not directly contact the inner wall of the transition tank 111. This ensures that even if the protruding ring 1123 undergoes expansion deformation under the action of heat, it will not contact the inner wall of the transition tank 111, nor will it deform the transition tank 111, thereby ensuring the overall structural reliability of the wall bushing 100.

[0051] In other embodiments, the convex ring may also be provided on the lower surface of the transition plate, or convex rings may be provided on both the upper and lower surfaces. The essence of the two embodiments is to expand the contact area between the conductive rod and the transition plate and improve the bending resistance of the conductive rod.

[0052] In other embodiments, the transition plate may also be a flat plate, and the shape of the transition plate is not specifically limited.

[0053] In this embodiment, transition tank 111 is a cylindrical tank with a first through-hole 1111 defined at its upper end and a cylindrical cavity formed through its lower end. First through-hole 1111 communicates with the cylindrical cavity. Transition tank 111 is fixedly connected to transition plate 112, and conductive rod 120 is inserted through first through-hole 1111 and second through-hole 1121. The annular cavity surrounding conductive rod 120 forms accommodating chamber 113.

[0054] In other embodiments, the shape of the transition tank may also be non-cylindrical, as long as it can be adapted to the connected components.

[0055] In this embodiment, a plurality of annular grooves 1112 are provided on the sidewall of the transition tank 111 surrounding the conductive rod 120. The annular grooves 1112 act as particle traps, absorbing metal particles in the transition tank 111 and ensuring stable electrical performance of the head of the wall bushing 100.

[0056] In this embodiment, there are four annular grooves 1112. In other embodiments, the number of annular grooves is not limited and can be appropriately designed based on the dimensions of the inner wall of the transition tank. However, it is understood that the greater the number and the denser the annular grooves, the better the metal particle adsorption effect.

[0057] In this embodiment, the annular groove 1112 is in the shape of a rectangular groove. In other embodiments, the annular groove may also be in the shape of an arc groove or an irregular groove. No specific limitation is imposed on the shape.

[0058] In this embodiment, a first connecting portion 1114 extends from the lower end of the transition tank 111 along the outer circumference of the transition tank 111. The first connecting portion 1114 is sealed to the transition plate 112. The provision of the first connecting portion 1114 facilitates the fixed connection between the transition tank 111 and the transition plate 112. The sealed connection prevents moisture from invading the interior of the transition tank 111, thereby preventing it from affecting electrical performance.

[0059] In this embodiment, a first sealing groove 1122 is provided on the transition plate 112, and a sealing ring (not shown) is provided in the first sealing groove 1122. In other embodiments, the first sealing groove may also be provided on the first connecting portion, or both the first connecting portion and the transition plate may have sealing grooves and be provided with sealing rings.

[0060] In this embodiment, the first connection portion 1114 and the transition plate 112 are provided with corresponding through holes and are fixedly connected by bolts (not shown in the figure). In other embodiments, the connection between the first connection portion and the transition plate can be adhesive bonding, welding, or a combination of the above fixing connection methods.

[0061] In this embodiment, the portion of the conductive rod 120 located above the protective bellows 150 is solid, while the portion of the conductive rod 120 located below the protective bellows 150 is hollow. The solid portion of the conductive rod 120 provides good electrical conductivity, while the hollow portion reduces the weight of the conductive rod, thereby reducing the overall weight of the wall bushing 100 and reducing costs.

[0062] In other embodiments, the conductive rod may be a fully solid structure or a fully hollow structure. The conductive rod is located at and above the protective bellows. The hollow conductive rod may be provided with a larger wall thickness.

[0063] In this embodiment, threaded holes are provided on the side of flange 153 that contacts transition plate 112, and corresponding through holes are provided on transition plate 112. Flange 153 and transition plate 112 are threadedly connected via bolts. The threaded holes are provided on the side of flange 153 that contacts transition plate 112, rather than on transition plate 112, for assembly purposes; this structure facilitates assembly. In this embodiment, the conductive rod 120 is provided with a thread in the area below the transition plate 112. The assembly order of the wall sleeve 100 is as follows: after the assembly of other components is completed, the second round nut 157 is sleeved down from the head of the conductive rod 120 and screwed onto the lower edge of the threaded area of ​​the conductive rod 120 to prevent the nut from loosening due to vibration or the like. Then, the protective bellows 150 with the filter element 160 assembled is sleeved down from the head of the conductive rod 120, with the upper through hole 151 at the top and the lower through hole 152 at the bottom. The lower connecting end 154 abuts against the second round nut 157. Then, the first round nut 156 is sleeved down from the head of the conductive rod 120 and screwed onto the conductive rod 120. The first round nut 156 is then abutted against the lower connecting end 154, i.e., the first and second round nuts 156, 157 are clamped on either side of the lower connecting end 154, thereby securing the protective bellows 150 to the conductive rod 120. The transition plate 112 is then inserted over the head of the conductive rod 120, and the through holes in the transition plate 112 are aligned with the threaded holes in the flange 153. Bolts are then threaded through the through holes into the threaded holes to securely connect the transition plate 112 to the flange 153. The transition tank 111 is then inserted over the head of the conductive rod 120 and securely connected to the transition plate 112. Finally, the terminal block 140 is securely connected to the transition tank 111, completing the subsequent assembly. During this process, since the main body and distal end of the conductive rod 120 are enclosed within the main insulating cavity, bolting through the flange 153 and then the transition plate 112 would be practically impractical. Therefore, the connection structure of this embodiment facilitates assembly.

[0064] The wall bushing 100 of this embodiment has a simple structure. The head assembly 110 replaces the structure of the traditional bellows, which can avoid the use of an axial dynamic sealing device, greatly improve the sealing reliability of the product, and reduce production costs. The provision of the protective bellows 150 further prevents possible metal chips or other debris from entering the main insulating cavity of the wall bushing 100, thereby improving the operational reliability of the product.

[0065] Example 2:

[0066] like Figure 4 As shown, this embodiment provides a wall bushing 200 , which is different from the first embodiment in that a non-metallic lining 230 is added.

[0067] In this embodiment, a non-metallic lining 230 is provided on the inner wall of the protruding ring 2123. The non-metallic lining 230 prevents the friction between the conductive rod 220 and the transition plate 212 and the transition tank 211 from generating metal chips, thereby improving the operational reliability of the product.

[0068] In this embodiment, the inner wall of the raised ring 2123 is provided with a plurality of grooves, into which the non-metallic liner 230 is embedded. This structure allows the non-metallic liner 230 to be embedded in the grooves in a broken-loop manner. That is, the non-metallic liner 230 is a strip-shaped structure rather than a full-loop structure. The length of the non-metallic liner 230 can be adjusted according to the size of the groove to allow it to fit into the groove, facilitating installation and construction. Furthermore, the provision of grooves can reduce the amount of non-metallic liner 230 used, lowering production costs. Compared to a larger non-metallic liner having a whole piece installed on the inner wall of the raised ring 2123, the broken-loop non-metallic liner 230 embedded in the inner wall of the groove is more convenient for installation and fixation. During use, the non-metallic liner 230 will not shift on the inner wall of the raised ring 2123.

[0069] In other embodiments, the inner wall of the first through hole and the inner wall of the second through hole are provided with a non-metallic lining to avoid the friction between the conductive rod and the transition plate and the transition tank to generate metal particles, thereby improving the operational reliability of the product.

[0070] In other embodiments, a non-metal lining may be provided only on the inner wall of the first through hole or the inner wall of the second through hole.

[0071] In other embodiments, the non-metallic lining may be continuously provided in the area where the conductive rod contacts other metal conductors, so that a gap exists between the conductive rod and other metal conductors. The absence of contact can reduce or even prevent the generation of metal particles.

[0072] In other embodiments, the non-metallic lining can also be fixedly set on the conductive rod, that is, the non-metallic lining only needs to be fixedly connected to the conductive rod or the inner wall of the first through hole, the inner wall of the second through hole, or the inner wall of the convex ring.

[0073] In this embodiment, the non-metallic lining 230 is a polytetrafluoroethylene (PTFE) lining. The PTFE lining offers excellent insulation, wear resistance, and chemical corrosion resistance. If an arc generates corrosive gases during operation of the wall bushing 200, the PTFE lining maintains its performance unaffected. This ensures that the non-metallic lining 230 remains in service and remains effective, preventing wear and tear.

[0074] In other embodiments, if the gas generated by the arc of the insulating gas filled in the wall bushing is non-corrosive gas or slightly corrosive gas, the non-metallic lining can also be any one of the linings with insulating and wear-resistant properties, such as polyester lining or glass fiber lining.

[0075] Since the wall bushing 200 of this embodiment is provided with the non-metallic lining 230 , the contact between the conductive rod 220 and other metal conductors can be reduced or avoided, thereby reducing the generation of metal particles and improving the reliability of product operation.

[0076] Example 3:

[0077] like Figure 5-6 As shown, this embodiment provides a wall bushing 300 , which is different from the second embodiment in the structure of the connection terminal 340 of the wall bushing 300 of this embodiment.

[0078] In this embodiment, the terminal block 340 comprises, in sequence, a connection portion 341, a receiving portion 342, and a connecting portion 343. The receiving portion 342 accommodates the end of the conductive rod 320 and electrically connects to the conductive rod 320. The connecting portion 343 is sealedly connected to the upper end of the transition tank 311. The terminal block 340 is an electrical connection component of the wall bushing 300 and is used for electrical connection to other devices. The provision of the connecting portion 343 facilitates the fixed connection between the terminal block 340 and the transition tank 311.

[0079] In this embodiment, a second sealing groove 314 is provided between the connecting portion 343 of the terminal block 340 and the upper end of the transition tank 311. A second sealing ring (not shown) is provided in the second sealing groove 314. Specifically, the second sealing groove 314 is provided at the upper end of the transition tank 311. In other embodiments, the second sealing groove may be provided at the connecting portion, or both the connecting portion and the upper end of the transition tank may be provided with sealing grooves.

[0080] In this embodiment, the connecting portion 343 is provided with a through hole 3431, and the upper end of the transition tank 311 is provided with a corresponding screw hole. The connecting portion 343 and the transition tank 311 are connected by screws (not shown) passing through the through hole 3431 and screwing into the screw hole. In other embodiments, the connection between the connecting portion and the transition tank can be glued, welded, or a combination of these fixed connection methods.

[0081] In this embodiment, a spring contact finger 344 is provided at the end of the conductive rod 320. The spring contact finger 344 abuts the inner wall of the accommodating portion 342, and a gap 346 exists between the accommodating portion 342 and the end of the conductive rod 320 along the axial direction of the conductive rod 320. The spring contact finger 344 is in close contact with both the inner wall of the accommodating portion 342 and the end of the conductive rod 320, ensuring a stable electrical connection between the terminal block 340 and the end of the conductive rod 320. This maintains the same electrical potential across the head assembly and alleviates the issue of head heating. The gap 346 between the accommodating portion 342 and the end of the conductive rod 320 along the axial direction of the conductive rod 320 ensures sufficient space for expansion and contraction of the conductive rod 320 when it undergoes axial deformation due to thermal expansion and contraction, preventing the conductive rod 320 from bending due to a fixed connection or contact with the inner wall of the accommodating portion 342.

[0082] In this embodiment, an annular groove 345 is provided on the inner wall of the accommodating portion 342. A spring contact finger 344 is housed within the annular groove 345. The spring contact finger 344 abuts the inner wall of the accommodating portion 342, electrically connecting the accommodating portion 342 to the end of the conductive rod 320, maintaining equal potential across the head assembly and addressing head heating issues. In other embodiments, the annular groove may not be provided within the accommodating portion. A gap may be provided between the inner wall of the accommodating portion and the end of the conductive rod, allowing the spring contact finger to be pressed between the inner wall of the accommodating portion and the conductive rod, thereby maintaining a relatively fixed position of the spring contact finger.

[0083] The wall bushing 300 of this embodiment, due to the ingenious structural arrangement of the terminal block 340, meets the requirements of electrical connection and equipotential at the head of the wall bushing 300. At the same time, when the conductive rod 320 undergoes axial deformation due to thermal expansion and contraction, it can ensure that the conductive rod 320 has sufficient expansion and contraction space, thereby avoiding the conductive rod 320 from bending due to fixed connection or contact with the inner wall of the accommodating portion 342.

[0084] Example 4:

[0085] like Figure 7-8 As shown, this embodiment provides a wall bushing 400 , which is different from the third embodiment in that the wall bushing 400 of this embodiment further includes a hollow insulator 470 .

[0086] In this embodiment, the wall bushing 400 further includes a hollow insulator 470, a flange 471 of which is sealed to the lower surface of the transition plate 412, and the conductive rod 420 passes through the hollow insulator 470. The hollow insulator 470 provides insulation protection for the internal conductor of the wall bushing 400.

[0087] In this embodiment, a third sealing groove 4711 is provided between the flange 471 of the hollow insulator 470 and the transition plate 412. A third sealing ring (not shown) is provided in the third sealing groove 4711. Specifically, the third sealing groove 4711 is provided on the flange 471. In other embodiments, the third sealing groove may be provided on the lower surface of the transition plate, or sealing grooves may be provided on the lower surfaces of both the flange and the transition plate.

[0088] In this embodiment, a pressure-equalizing ball 480 is disposed on the periphery of the head assembly 410 and is fixedly connected to the head assembly 410. The pressure-equalizing ball 480 serves to equalize the pressure, preventing abnormal corona discharge from occurring when the head assembly 410 is charged. A pressure-equalizing ball is also disposed at the end of the wall bushing 400.

[0089] In this embodiment, the conductive rod 420 is inserted into the hollow insulator 470 and fixedly connected to the end of the wall bushing 400, ensuring that the conductive rod 420 passing through the head assembly 410 will not be displaced when the conductive rod 420 expands or contracts due to heat.

[0090] In this embodiment, specifically, the overall structure of the wall bushing 400 is that the conductive rod 420 is inserted into the hollow insulator 470 and is fixedly connected to the end of the wall bushing 400. The conductive rod 420 only needs to pass through the head assembly 410. Due to the sealed connection between the terminal 440 and the transition tank 411, the conductive rod 420 and the transition tank 411, and the conductive rod 420 and the transition plate 412 do not need to be fixed and sealed. This can avoid the use of an axial dynamic sealing device between the transition tank 411 and the conductive rod 420, greatly improving the product sealing reliability. At the same time, since the bellows are eliminated, the production cost can be reduced. Moreover, when the length of the conductive rod 420 changes due to thermal expansion and contraction, the end of the conductive rod 420 is fixed, and axial relative movement occurs between the head of the conductive rod 420 and the transition tank 411. At this time, since there is a gap 446 between the terminal 440 and the end of the conductive rod 420, the gap 446 provides space for axial movement, and the conductive rod 420 will not bend due to the increase in length. From this aspect, the reliability of the product can also be improved.

[0091] In this embodiment, due to the provision of the protective bellows 450, a cavity is formed which is composed of the protective bellows 450, the conductive rod 420, the transition plate 412 and the filter element 460, and only allows gas exchange. There is no gap between the protective bellows 450 and the conductive rod 420, and only gas is allowed to pass through under unsealed conditions; a channel and a filter element 460 are provided between the protective bellows 450 and the transition plate 412, and the metal particles inside the protective bellows 450 will be blocked by the filter element 460 and cannot migrate to the outside of the protective bellows 450. In this structure, there are no other outlets and inlets, which can ensure that the metal particles inside the protective bellows 450 will not enter the hollow insulator 470 of the wall bushing 400 during the inflation and deflation process, thereby ensuring the reliability of the operation of the wall bushing 400. Furthermore, since the protective bellows 450 and the conductive rod 420 are fixedly connected and no displacement will occur between the two, when the conductive rod 420 is deformed due to thermal expansion and contraction, the size of the protective bellows 450 also changes accordingly to ensure that the conductive rod 420 does not bend or the transition plate 412 does not deform. Therefore, the protective bellows 450 is mainly used to utilize its own elastic deformation to provide space for the conductive rod 420 to deform.

[0092] In this embodiment, the hollow insulator 470 is a composite insulator made of composite materials. Composite insulators are lightweight, low-cost, and have excellent insulation and mechanical properties. In other embodiments, the hollow insulator can be an insulator made of other materials, such as a porcelain insulator.

[0093] In this embodiment, the hollow insulator 470 is a two-section insulator with a mounting structure 472 disposed between the two sections. Mounting structure 472 is used to mount the wall bushing 400 on a wall. Specifically, the wall bushing 400 comprises a sequentially connected terminal block 440, a transition tank 411, a transition plate 412, and a hollow insulator 470. A conductive rod 420 is disposed within the hollow insulator 470. The ends of the conductive rod 420 are connected to the terminal block 440, and the distal ends of the conductive rod 420 are fixed to the distal ends of the hollow insulator 470.

[0094] During installation, the wall bushing 400 can be installed at a certain angle or horizontally along its axis. In this embodiment, the wall bushing 400 is installed at an angle, with the head of the wall bushing 400 higher than the end of the wall bushing 400. In this case, metal particles within the transition tank 411 fall into the annular groove 4112 due to gravity. The annular groove 4112 acts as a particle trap, absorbing the metal particles within the transition tank 411 and preventing them from floating and migrating within the transition tank 411, thereby ensuring stable electrical performance at the head of the wall bushing 400.

[0095] The wall bushing of the present invention has a simple structure. The head assembly replaces the structure of the traditional bellows, which can avoid the use of an axial dynamic sealing device, greatly improving the sealing reliability of the product and reducing production costs. The provision of the protective bellows further prevents possible metal chips or other debris from entering the main insulating cavity of the wall bushing, thereby improving the operational reliability of the product.

[0096] The technical content and technical features of the present invention have been disclosed above. However, it is understood that, based on the creative ideas of the present invention, those skilled in the art may make various changes and improvements to the above-mentioned structures and materials, including combinations of the technical features disclosed or claimed herein, and obviously including other combinations of these features. Such variations and / or combinations fall within the technical field involved in the present invention and fall within the scope of protection of the claims of the present invention.

Claims

1. A wall bushing, characterized by: Including head assembly, conductive rod and protective bellows and terminal blocks; The head assembly is provided with a receiving cavity, and a first through hole and a second through hole communicating with the receiving cavity are coaxially provided at the upper and lower ends of the head assembly, respectively. The head assembly includes a transition tank and a transition plate connected to each other, the first through hole being provided at the upper end of the transition tank, the lower end of the transition tank being passed through, and the second through hole being provided at the transition plate. The transition tank and the transition plate are fixedly connected so that the receiving cavity is formed in the transition tank around the conductive rod; a convex ring is provided on the upper surface of the transition plate around the second through hole, and the convex ring is located in the receiving cavity; The protective bellows is an annular shell that passes through the upper and lower parts, and the protective bellows is respectively provided with an upper through hole and a lower through hole, and the conductive rod passes through the first through hole, the second through hole, the upper through hole and the lower through hole, and the protective bellows is provided with an upper connecting end around the upper through hole, and the upper connecting end is fixedly connected to the lower end of the head assembly around the second through hole, and the lower through hole is fixedly connected to the conductive rod, and there is no gap between the protective bellows and the conductive rod, wherein the upper connecting end is a flange extending radially along the upper through hole, the flange is affixed and fixedly connected to the lower end of the head assembly, a mounting hole is provided on the flange, and a mutually communicating channel is provided between the mounting hole and the upper through hole, a filter element is installed in the mounting hole, and the filter element is only for gas exchange between the inside of the protective bellows and the outside of the protective bellows, and the filter element includes a filter portion and a filter element connecting portion, and the filter element connecting portion is cooperatively connected with the mounting hole; The connection terminal is electrically connected to the conductive rod and seals and covers the head assembly and the conductive rod.

2. The wall bushing according to claim 1, wherein: The filter element is a metal mesh structure.

3. The wall bushing according to claim 1, wherein: The diameter of the lower through hole is smaller than the minimum inner diameter of the protective bellows. A lower connecting end is arranged around the lower through hole. A first round nut and a second round nut are respectively arranged on both sides of the lower connecting end. The first round nut and the second round nut are respectively connected to the conductive rod through threaded connections to clamp the lower connecting end so that the protective bellows is fixedly connected to the conductive rod.

4. The wall bushing according to claim 1, wherein: A plurality of annular grooves are provided on the circumferential inner wall of the transition tank.

5. The wall bushing according to claim 1, wherein: A threaded hole is provided on a surface of the flange that is in contact with the transition plate, and a through hole corresponding to the threaded hole is provided on the transition plate. The flange and the transition plate are threadedly connected by bolts.

6. The wall bushing according to claim 1, wherein: The inner wall of the first through hole and / or the inner wall of the second through hole and / or the inner wall of the protruding ring is provided with a non-metallic lining.

7. The wall bushing according to claim 6, characterized in that: The inner wall of the convex ring is provided with a plurality of grooves, and the non-metallic lining is embedded in the grooves.

8. The wall bushing according to claim 1, wherein: The wiring terminal includes a wiring portion, an accommodating portion and a connecting portion in sequence. The accommodating portion is used to accommodate the end of the conductive rod and is electrically connected to the conductive rod. The connecting portion is sealed and connected to the upper end of the head assembly.

9. The wall bushing according to claim 8, characterized in that: A spring contact finger is provided at the end of the conductive rod, the spring contact finger abuts against the inner wall of the accommodating portion, and a gap exists between the accommodating portion and the end of the conductive rod along the axial direction of the conductive rod.

10. The wall bushing according to claim 1, characterized in that: The wall bushing further includes a hollow insulator, which is sealed and connected to the transition plate, and the conductive rod passes through the hollow insulator.

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