A bus duct expansion joint connection structure

Abstract

The utility model provides a bus duct's expansion joint connecting structure belongs to bus duct connecting technical field, this bus duct's expansion joint connecting structure, including fixed base, sliding seat and conducting strip subassembly, fixed base is fixedly connected through bolt in the end of first section bus duct, and the inside of fixed base forms the rectangular sliding cavity, one end of sliding seat is fixedly connected through bolt in the end of second section bus duct, and the other end of sliding seat extends into the sliding cavity and is slidably arranged in the sliding cavity along the bus duct axial direction, conducting strip subassembly sets up between fixed base and sliding seat, its characterized in that, the sliding cavity inner wall of fixed base is provided with a plurality of along the bus duct axial extension's guide convex strip, and the end of sliding seat that extends into the sliding cavity outer wall is provided with the guide groove that cooperates with guide convex strip, and the guide convex strip and guide groove form the sliding guide cooperation of intercalation, and the cross section of guide convex strip is trapezoidal structure and the upper base width of trapezoidal is less than lower base width.

Description

Technical Field

[0001] This utility model belongs to the field of busbar trunking connection technology, and more specifically, it relates to an expansion joint connection structure for busbar trunking. Background Technology

[0002] Busbar trunking, as a new type of power distribution conductor system, is widely used in power transmission and distribution systems in industrial plants, commercial buildings, data centers, and other places. It has advantages such as large current carrying capacity, good heat dissipation, and convenient installation and maintenance. Because busbar trunking is usually laid horizontally or vertically along buildings and is relatively long, it experiences significant thermal expansion and contraction when the ambient temperature changes or the load current fluctuates. If rigid connections are used between the sections of the busbar trunking, the stress generated by thermal expansion and contraction can lead to deformation, loosening of connections, or even damage. To accommodate the thermal expansion and contraction of busbar trunking, existing technologies generally employ expansion joint connection structures, connecting the busbar trunking in sections and absorbing the displacement caused by thermal expansion and contraction through the sliding mechanism of the expansion joint. Existing busbar trunking expansion joint connection structures typically include a fixed seat and a sliding seat fixed to the ends of the two busbar trunking sections. The sliding seat is inserted into the sliding cavity of the fixed seat and can slide axially. Electrical connection is maintained by a conductive plate assembly located between the fixed seat and the sliding seat. However, the existing guiding mechanism design is not perfect. The sliding seat and the sliding cavity usually adopt a simple cylindrical surface fit or planar fit, which has weak guiding ability. When the busbar groove undergoes thermal expansion and contraction displacement, the sliding seat is prone to radial displacement and rotation in the sliding cavity. This causes changes in the contact position between the conductive sheet assembly and the sliding seat, uneven contact pressure distribution, increased contact resistance, and local overheating. In severe cases, it can even cause arc discharge, threatening system safety. At the same time, the radial movement and rotation of the sliding seat aggravates the wear of the guiding surface and conductive contact surface, shortens the service life of the expansion joint, and increases maintenance costs and system failure risk. Utility Model Content

[0003] In view of this, the present invention provides an expansion joint connection structure for busbar trunking, which can solve the problem that in the prior art, when the busbar trunking undergoes thermal expansion and contraction, the sliding component is prone to radial displacement and rotation within the sliding cavity, leading to unstable conductive contact, increased contact resistance, local overheating, or even arc discharge. At the same time, the radial movement and rotation of the sliding component exacerbates the wear of the guide mechanism and conductive components, shortens the service life of the expansion joint, and affects the safe and reliable operation of the busbar trunking system.

[0004] This utility model is implemented as follows:

[0005] This utility model provides a busbar expansion joint connection structure for connecting two busbar sections and accommodating their thermal expansion and contraction displacement. It includes a fixed base, a sliding base, and a conductive sheet assembly. The fixed base is bolted to the end of the first busbar section, and a rectangular sliding cavity is formed inside the fixed base. One end of the sliding base is bolted to the end of the second busbar section, and the other end of the sliding base extends into the sliding cavity and is slidably disposed within the sliding cavity along the axial direction of the busbar. The conductive sheet assembly is disposed between the fixed base and the sliding base to maintain electrical connection when the sliding base undergoes axial displacement relative to the fixed base. The inner wall of the sliding cavity of the fixed base is provided with several guide protrusions extending along the axial direction of the busbar. The outer wall of the end of the sliding base extending into the sliding cavity is provided with guide grooves that cooperate with the guide protrusions. The guide protrusions and guide grooves interlock to form a sliding guide fit. The cross-section of the guide protrusion is trapezoidal, and the width of the upper base of the trapezoid is smaller than the width of the lower base.

[0006] The technical advantages of the expansion joint connection structure for busbar trunking provided by this utility model are as follows: By setting a guide protrusion extending axially along the busbar trunking on the inner wall of the sliding cavity of the fixed seat, and setting a guide groove that cooperates with the guide protrusion on the outer wall of the sliding seat, the guide protrusion and the guide groove are interlocked to form a sliding guide fit, which can effectively constrain the movement trajectory of the sliding seat in the sliding cavity, prevent the sliding seat from radially shifting or rotating during thermal expansion and contraction, and ensure the stability and reliability of the expansion joint connection; the cross-section of the guide protrusion is trapezoidal and the width of the upper base of the trapezoid is smaller than the width of the lower base. This trapezoidal structure makes the guide protrusion and the guide groove form a self-locking fit, which can generate greater pull-out force when subjected to radial force, effectively preventing the sliding seat from coming out of the sliding cavity. At the same time, the trapezoidal structure has a guiding effect during assembly, making it easy for the sliding seat to be accurately inserted into the sliding cavity.

[0007] Based on the above technical solution, the expansion joint connection structure of the busbar trunking of this utility model can be further improved as follows:

[0008] The conductive sheet assembly is composed of multiple stacked elastic copper sheets. One end of each elastic copper sheet is fixedly connected to the inner wall of the fixed base, and the other end is a free end that elastically contacts the outer wall of the sliding base.

[0009] The beneficial effects of adopting the above-mentioned improved scheme are as follows: The conductive sheet assembly is constructed using multiple stacked elastic copper sheets. One end of each elastic copper sheet is fixedly connected to the inner wall of the fixed base, while the other end is a free end that elastically contacts the outer wall of the sliding base. This structural design ensures that when the sliding base undergoes axial displacement relative to the fixed base, the elastic copper sheet can maintain close contact with the outer wall of the sliding base through its own elastic deformation, ensuring the continuity and stability of the electrical connection. The multi-sheet stacked design increases the conductive cross-sectional area, reduces contact resistance, and improves conductivity. Simultaneously, the multiple elastic copper sheets disperse the contact pressure, reducing wear on individual copper sheets and extending service life.

[0010] Furthermore, the length of the guide ridge along the axial direction of the busbar groove is greater than the sum of the length of the portion of the sliding seat extending into the sliding cavity along the axial direction of the busbar groove and the maximum thermal expansion and contraction displacement of the busbar groove.

[0011] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by making the length of the guide ridge along the axial direction of the busbar groove greater than the sum of the length of the portion of the sliding seat extending into the sliding cavity along the axial direction of the busbar groove and the maximum thermal expansion and contraction displacement of the busbar groove, it is ensured that when the busbar groove experiences maximum thermal expansion and contraction displacement, the sliding seat can still remain within the guiding range of the guide ridge. The guide ridge and the guide groove always remain in an engaged state, preventing the sliding seat from sliding out of the guiding range of the guide ridge and losing its guiding constraint. This ensures the reliability and safety of the expansion joint throughout the entire operating temperature range and avoids electrical connection interruption or mechanical damage caused by guide failure.

[0012] Furthermore, the width ratio of the upper base to the lower base of the trapezoidal cross-section of the guide protrusion is 1:2.5 to 1:1.5, and the cross-sectional shape of the guide groove is adapted to the trapezoidal cross-section of the guide protrusion.

[0013] The beneficial effects of adopting the above-mentioned improved scheme are as follows: setting the width ratio of the upper base to the lower base of the trapezoidal cross-section of the guide convex strip to 1:2.5 to 1:1.5 ensures that the guide convex strip and the guide groove have sufficient fitting depth and self-locking capability, while avoiding the problems of assembly difficulties due to excessive trapezoidal angle or insufficient self-locking force due to excessively small trapezoidal angle. Within this range, the trapezoidal structure can generate appropriate wedging effect when subjected to radial force, effectively resisting the radial movement of the sliding seat. At the same time, the frictional resistance is small when the sliding seat slides axially, ensuring that the expansion joint has both good guiding and positioning performance and smooth sliding performance. The cross-sectional shape of the guide groove is adapted to the trapezoidal cross-section of the guide convex strip, further improving the fitting accuracy.

[0014] Furthermore, four guide protrusions are evenly distributed circumferentially on the inner wall of the sliding cavity of the fixed seat, and four guide grooves are correspondingly provided on the outer wall of the sliding seat.

[0015] The beneficial effects of the above-mentioned improvement scheme are as follows: Four guide protrusions are evenly distributed circumferentially on the inner wall of the sliding cavity of the fixed seat, and four guide grooves are correspondingly provided on the outer wall of the sliding seat. This evenly distributed multi-point guiding structure makes the sliding seat subject to a circumferentially balanced constraint force in the sliding cavity, effectively preventing the sliding seat from shifting or tilting in any radial direction, and improving the stability and reliability of the guide. The number of four guide protrusions can ensure sufficient guiding capacity while avoiding excessive guide protrusions that would increase frictional resistance and processing difficulty, thus achieving a balance between guiding performance and smooth sliding. At the same time, the evenly distributed structure makes the sliding seat subjected to uniform force, reducing local stress concentration and extending service life.

[0016] Furthermore, an annular boss is provided on the outer wall of the end of the sliding seat that extends into the sliding cavity. The outer diameter of the annular boss is smaller than the inner diameter of the sliding cavity and larger than the outer diameter of the sliding seat body. The annular boss is located between the guide groove and the end face of the sliding seat.

[0017] The beneficial effects of the above-mentioned improvement scheme are as follows: An annular boss is provided on the outer wall of the end of the sliding seat that extends into the sliding cavity. The outer diameter of the annular boss is smaller than the inner diameter of the sliding cavity and larger than the outer diameter of the sliding seat body. The annular boss is located between the guide groove and the end face of the sliding seat. This structural design allows the annular boss to play a limiting role when the sliding seat is inserted into the sliding cavity, preventing the sliding seat from being over-inserted, which would cause the guide protrusion and the guide groove to fit too tightly and increase the sliding resistance. The annular gap formed between the annular boss and the inner wall of the sliding cavity can accommodate a certain amount of manufacturing error and thermal deformation, improving the tolerance of assembly. At the same time, the annular boss increases the contact area between the sliding seat and the sliding cavity, improving the stability of the connection and reducing the shaking of the sliding seat during the sliding process.

[0018] Furthermore, a sealing ring is provided between the mating surfaces of the fixed seat and the sliding seat. The sealing ring is embedded in an annular sealing groove provided at the entrance of the sliding cavity of the fixed seat, and the inner diameter of the sealing ring is smaller than the outer diameter of the extended portion of the sliding seat.

[0019] The beneficial effects of adopting the above-mentioned improved scheme are as follows: A sealing ring is set between the mating surfaces of the fixed seat and the sliding seat. The sealing ring is embedded in the annular sealing groove set at the entrance of the sliding cavity of the fixed seat. The inner diameter of the sealing ring is smaller than the outer diameter of the sliding seat extension. This sealing structure can effectively prevent dust, moisture and other impurities from entering the sliding cavity, protect the guide protrusion, guide groove and conductive sheet assembly from contamination and corrosion, and extend the service life of the expansion joint. The radial clamping force generated by the sealing ring on the sliding seat can also increase the contact tightness between the sliding seat and the fixed seat, reduce the radial movement of the sliding seat, and further improve the stability of the connection. At the same time, the sealing structure can prevent electric arc or sparks from leaking from the inside of the sliding cavity, improving the safety of use.

[0020] Furthermore, both the fixed base and the sliding base are made of aluminum alloy, and the elastic copper sheet of the conductive sheet assembly is made of phosphor bronze.

[0021] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: Using aluminum alloy to make the fixed and sliding seats, aluminum alloy has the characteristics of low density, high strength, good thermal conductivity, and strong corrosion resistance, which can reduce the overall weight of the expansion joint and reduce the additional load on the busbar. At the same time, the good thermal conductivity of aluminum alloy helps to dissipate the heat generated during the conduction process and prevent local overheating. Using phosphor bronze to make the elastic copper sheets of the conductive sheet assembly, phosphor bronze has excellent elasticity, conductivity, and wear resistance, and can maintain stable elastic force and good conductivity during long-term elastic deformation and sliding friction, reducing contact resistance, reducing energy consumption, and extending the service life of the conductive sheet assembly. This material combination achieves a balance between lightweight, high conductivity, and high reliability.

[0022] Furthermore, the sliding cavity of the fixed seat has a rectangular cylindrical structure, and the end of the sliding seat that extends into the sliding cavity has a rectangular columnar structure that is adapted to the sliding cavity.

[0023] The beneficial effects of adopting the above-mentioned improved scheme are as follows: the sliding cavity of the fixed seat has a rectangular cylindrical structure, and the end of the sliding seat that extends into the sliding cavity has a rectangular columnar structure that matches the sliding cavity. Compared with the circular fitting structure, this rectangular fitting structure has stronger torsional resistance and can effectively prevent the sliding seat from rotating in the sliding cavity, ensuring the stability of the contact position between the conductive sheet assembly and the sliding seat, and avoiding poor contact or increased wear caused by rotation. The rectangular structure also makes it easier to process guide protrusions and guide grooves on the inner wall of the sliding cavity and the outer wall of the sliding seat, improving the processing accuracy and assembly accuracy. At the same time, the rectangular structure makes the shape of the expansion joint match the rectangular cross-section of the busbar, which is convenient for installation and fixing, and improves the compactness and aesthetics of the overall structure.

[0024] Furthermore, each of the elastic copper sheets has a wavy bend between its fixed end and free end. The wavy bend includes at least two peaks and troughs arranged along the axial direction of the busbar groove. The free end of the elastic copper sheet is bent toward the outer wall of the sliding seat to form a contact protrusion.

[0025] The beneficial effects of the above-mentioned improvement scheme are as follows: A wavy bend is formed between the fixed end and the free end of each elastic copper sheet. The wavy bend includes at least two peaks and troughs arranged along the axial direction of the busbar groove. This wavy structure increases the effective length of the elastic copper sheet, enabling it to maintain stable elastic force within a large axial displacement range, avoiding a sharp increase or decrease in elastic force due to excessive displacement. The wavy structure can also absorb the vibration and impact generated by the sliding seat during sliding, reducing the impact on conductive contact and improving the stability of the electrical connection. A contact protrusion is formed by bending the free end of the elastic copper sheet towards the outer wall of the sliding seat. The contact protrusion can concentrate the contact pressure, reduce the contact area, and lower the contact resistance. At the same time, the contact protrusion has a certain self-cleaning effect, which can scrape off the oxide layer and contaminants on the outer wall of the sliding seat during sliding, maintaining good conductive contact.

[0026] Compared with existing technologies, the beneficial effects of the expansion joint connection structure for busbar trunking provided by this utility model are as follows: This utility model provides a guide protrusion extending axially along the busbar trunking on the inner wall of the sliding cavity of the fixed seat, and a guide groove that mates with the guide protrusion on the outer wall of the sliding seat. This allows the guide protrusion and guide groove to interlock and form a sliding guide fit. Furthermore, the cross-section of the guide protrusion is designed as a trapezoidal structure with an upper base width smaller than the lower base width, achieving precise constraint on the movement trajectory of the sliding seat. This effectively prevents radial offset and rotation of the sliding seat during thermal expansion and contraction, ensuring the stability of the contact position between the conductive sheet assembly and the sliding seat, reducing contact resistance, and minimizing the risk of localized overheating and arc discharge. The trapezoidal guide structure also has a self-locking function, capable of withstanding large radial forces without disengaging, thus improving the reliability and safety of the connection. The use of multi-piece stacked... The addition of elastic copper sheets as conductive sheet assemblies, combined with the design of wavy bends and contact protrusions, enables the conductive sheet assembly to maintain stable elastic contact force and good conductivity over a large axial displacement range, extending the service life of the conductive assembly. By rationally setting the length of the guide protrusions, the width ratio of the trapezoidal cross-section, the number and distribution of the guide protrusions, and adding auxiliary structures such as annular bosses and sealing rings, an optimized balance between guiding performance, smooth sliding, sealing, and assembly tolerance is achieved. The use of high-performance materials such as aluminum alloy and phosphor bronze, along with the rectangular mating structure design, further improves the lightweight, high conductivity, high reliability, and ease of assembly of the expansion joint. This allows the busbar expansion joint connection structure of this utility model to operate stably for a long time under various working environments and temperature conditions, significantly improving the safety and reliability of the busbar system. 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 This is a schematic diagram of an expansion joint connection structure for a busbar trunking.

[0029] Figure 2 A front view of the connection of an expansion joint connection structure for a busbar trunking;

[0030] Figure 3 This is a cross-sectional view of an expansion joint connection structure for a busbar trunking.

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

[0032] 1. Fixed base; 11. Guide protrusion; 2. Sliding base; 21. Guide groove; 3. Conductive sheet assembly. 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 diagram shows a first embodiment of a busbar expansion joint connection structure provided by this utility model. In this embodiment, it is used to connect two busbar sections and accommodate their thermal expansion and contraction displacement. It includes a fixed seat, a sliding seat, and a conductive sheet assembly. The fixed seat is fixedly connected to the end of the first busbar section by bolts, and a rectangular sliding cavity is formed inside the fixed seat. One end of the sliding seat is fixedly connected to the end of the second busbar section by bolts, and the other end of the sliding seat extends into the sliding cavity and is slidably disposed in the sliding cavity along the axial direction of the busbar. The conductive sheet assembly is disposed between the fixed seat and the sliding seat to maintain electrical connection when the sliding seat undergoes axial displacement relative to the fixed seat. The inner wall of the sliding cavity of the fixed seat is provided with several guide protrusions extending along the axial direction of the busbar. The outer wall of the end of the sliding seat that extends into the sliding cavity is provided with a guide groove that cooperates with the guide protrusions. The guide protrusions and the guide grooves are interlocked to form a sliding guide fit. The cross-section of the guide protrusion is trapezoidal, and the width of the upper base of the trapezoid is smaller than the width of the lower base.

[0035] In the above technical solution, the conductive sheet assembly is composed of multiple stacked elastic copper sheets. One end of each elastic copper sheet is fixedly connected to the inner wall of the fixed base, and the other end is a free end that elastically contacts the outer wall of the sliding base.

[0036] Furthermore, in the above technical solution, the length of the guide convex strip along the axial direction of the busbar groove is greater than the sum of the length of the portion of the sliding seat extending into the sliding cavity along the axial direction of the busbar groove and the maximum thermal expansion and contraction displacement of the busbar groove.

[0037] Furthermore, in the above technical solution, the width ratio of the upper base to the lower base of the trapezoidal cross-section of the guide protrusion is 1:2.5 to 1:1.5, and the cross-sectional shape of the guide groove is adapted to the trapezoidal cross-section of the guide protrusion.

[0038] Furthermore, in the above technical solution, four guide protrusions are evenly distributed circumferentially on the inner wall of the sliding cavity of the fixed seat, and four guide grooves are correspondingly provided on the outer wall of the sliding seat.

[0039] Furthermore, in the above technical solution, an annular boss is provided on the outer wall of the end of the sliding seat that extends into the sliding cavity. The outer diameter of the annular boss is smaller than the inner diameter of the sliding cavity and larger than the outer diameter of the sliding seat body. The annular boss is located between the guide groove and the end face of the sliding seat.

[0040] Furthermore, in the above technical solution, a sealing ring is provided between the mating surfaces of the fixed seat and the sliding seat. The sealing ring is embedded in the annular sealing groove provided at the entrance of the sliding cavity of the fixed seat, and the inner diameter of the sealing ring is smaller than the outer diameter of the part of the sliding seat that extends into it.

[0041] Furthermore, in the above technical solution, both the fixed seat and the sliding seat are made of aluminum alloy, and the elastic copper sheet of the conductive sheet assembly is made of phosphor bronze.

[0042] Furthermore, in the above technical solution, the sliding cavity of the fixed seat has a rectangular cylindrical structure, and the end of the sliding seat that extends into the sliding cavity has a rectangular columnar structure that matches the sliding cavity.

[0043] Furthermore, in the above technical solution, each elastic copper sheet has a wavy bend between the fixed end and the free end. The wavy bend includes at least two peaks and troughs arranged along the axial direction of the busbar groove. The free end of the elastic copper sheet is bent toward the outer wall of the sliding seat to form a contact protrusion.

[0044] The following is a specific embodiment 1 of this utility model: This embodiment provides an expansion joint connection structure for a busbar trunking system with a rated current of 3200A. The fixing base is made of 6061 aluminum alloy through extrusion molding, and has an overall rectangular cylindrical structure with external dimensions of 260mm in length, 180mm in width, and 140mm in height, and a wall thickness of 8mm. The internal sliding cavity is a rectangular cavity with internal dimensions of 244mm in length, 164mm in width, and 124mm in height. On the four inner walls of the sliding cavity, a guide ridge is provided along the axial direction of the busbar trunking. The four guide ridges are evenly distributed around the circumference of the sliding cavity, and the included angle between two adjacent guide ridges is 90°. The cross-section of each guide ridge is trapezoidal, with an upper base width of 10mm, a lower base width of 18mm, and a height of 12mm. The width ratio of the upper base to the lower base is 1:1.8, and the included angle between the two inclined planes of the trapezoid and the vertical plane is 33°. The guide ridge is 200mm long along the axial direction of the busbar groove, extending inward from the inlet of the sliding cavity. The sliding seat is also made of 6061 aluminum alloy, with an overall L-shaped structure. One end is a connecting flange, which is fixed to the end of the second section of the busbar groove by eight M10 bolts. The other end is a rectangular columnar extension, with external dimensions of 120mm in length, 158mm in width, and 118mm in height, matching the internal dimensions of the sliding cavity of the fixed seat, with a 3mm gap around the perimeter. On the four outer walls of the extension, a guide groove is machined at the position corresponding to the guide ridge. The cross-sectional shape of the guide groove precisely matches the trapezoidal cross-section of the guide ridge. The upper base width of the trapezoidal groove opening is 10.2mm, the lower base width is 18.2mm, and the depth is 12.2mm, with a fitting clearance of 0.1mm to 0.2mm, ensuring smooth sliding without significant wobble. A ring-shaped boss is provided circumferentially at a distance of 40mm from the end face of the sliding seat extension. The outer diameter of the ring-shaped boss is 6mm larger than the outer diameter of the extension body, and the width of the ring-shaped boss is 15mm. At the entrance of the sliding cavity of the fixed seat, a ring-shaped sealing groove with a depth of 4mm and a width of 8mm is provided at a distance of 5mm from the end face. An O-ring made of nitrile rubber is embedded in the sealing groove. The wire diameter of the sealing ring is 6mm and the inner diameter is 150mm. In the free state, the inner diameter of the sealing ring is smaller than the outer diameter of the sliding seat extension. When the sliding seat is inserted, the sealing ring is compressed to produce a sealing effect. The conductive sheet assembly consists of 12 elastic copper sheets. The elastic copper sheets are made of 0.8mm thick phosphor bronze sheet through stamping and bending processes. Each elastic copper sheet is 180mm long and 50mm wide. It is fixed to the inner wall of the sliding cavity of the fixed seat by two M6 bolts at a distance of 20mm from the end. The fixing position is located in the plane area between the guide protrusions. The elastic copper sheet forms a wavy bend from the fixed end to the free end, including 3 crests and 3 troughs. The height of each crest is 25mm, and the axial distance between the crests is 45mm.The free end of the elastic copper sheet is bent towards the outer wall of the sliding seat to form a contact protrusion with a length of 8mm. The end of the contact protrusion is arc-shaped with a radius of 2mm. Twelve elastic copper sheets are evenly distributed circumferentially within the sliding cavity, divided into three groups of four elastic copper sheets stacked in each group. The spacing between adjacent copper sheets is 2mm. Each group of elastic copper sheets corresponds to one phase conductor of the busbar, achieving three-phase conductive connection. When the sliding seat is not inserted, the distance between the free end contact protrusion of the elastic copper sheet and the inner wall of the fixed seat is 85mm. When the sliding seat is inserted into place, the outer wall of the sliding seat compresses the elastic copper sheet, causing an elastic deformation of 15mm. Each elastic copper sheet generates a contact pressure of approximately 8N on the outer wall of the sliding seat, and the twelve elastic copper sheets generate a total contact pressure of approximately 96N, ensuring good conductive contact. The guide ridge is 200mm long, the sliding seat extends 120mm into the sliding cavity, and the maximum thermal expansion and contraction displacement of the busbar trough within the temperature range of -20℃ to +60℃ is 50mm. The guide ridge is longer than 120mm plus 50mm, which is 170mm, leaving a 30mm safety margin to ensure that the guide ridge and guide groove remain in a fitted state throughout the entire operating temperature range. The total weight of the entire expansion joint connection structure is 12kg, and it can withstand a maximum axial tensile force of 15000N, a maximum radial force of 8000N, a contact resistance of less than 10 microohms, and a temperature rise of less than ambient temperature plus 40℃. In practical use, the expansion joint connection structure is installed in the middle section of an 80m long busbar system to absorb the thermal expansion and contraction displacement of the busbar. As the ambient temperature rises from 5℃ to 35℃, the total length of the busbar increases by approximately 24mm. The sliding seat slides smoothly for 12mm within the sliding cavity of the fixed seat. The conductive plate assembly maintains elastic contact with the sliding seat at all times. The electrical connection is stable and reliable, with no poor contact or overheating. The expansion joint operates smoothly without any abnormal noise, and the guide mechanism and conductive components show no obvious wear. This indicates that the structure is reasonably designed, performs well, and can meet the requirements for long-term stable operation of the busbar system.

[0045] The following is another specific embodiment 2 of this utility model: This embodiment 2 is an optimized design based on embodiment 1, specifically for busbar systems with higher current ratings, and is suitable for busbar systems with a rated current of 5000A. In this embodiment, the external dimensions of the fixing base are increased to 320mm in length, 240mm in width, and 180mm in height, and the wall thickness is increased to 10mm. The internal dimensions of the sliding cavity are correspondingly increased to 300mm in length, 220mm in width, and 160mm in height. The number of guide ridges is increased to 2 ridges on each inner wall surface, for a total of 8 guide ridges. The trapezoidal dimensions of the cross-section of each guide ridge remain unchanged: upper base width 10mm, lower base width 18mm, and height 12mm. However, the length of the guide ridge along the axial direction of the busbar is increased to 250mm to accommodate greater thermal expansion and contraction displacement. The number of elastic copper sheets in the conductive sheet assembly has been increased to 20, divided into 3 groups: two groups of 8 sheets each and one group of 4 sheets, corresponding to the three-phase conductors. The thickness of the elastic copper sheets has been increased to 1.0 mm, and the width to 60 mm. The contact pressure generated by each elastic copper sheet against the outer wall of the sliding seat has increased to approximately 12 N, resulting in a total contact pressure of approximately 240 N from the 20 elastic copper sheets, thus improving conductivity and contact stability. The number of guide grooves in the sliding seat extension has also been increased to 8, precisely matching the 8 guide protrusions on the fixed seat, further improving guidance stability and torsional resistance. The wire diameter of the sealing ring has been increased to 8 mm, and the inner diameter to 200 mm, improving sealing effect and durability.

[0046] The following is another specific embodiment 3 of this utility model: Embodiment 3 is an improved design of the busbar system used in harsh environments such as high temperature and high humidity, based on Embodiment 1. In this embodiment, the material of the fixed seat and the sliding seat is changed to 5052 aluminum alloy, which has better corrosion resistance, especially in high humidity and salt spray environments. The elastic copper sheet material of the conductive sheet assembly is changed to beryllium bronze. Compared with phosphor bronze, beryllium bronze has higher strength and elastic limit, and can maintain more stable elastic performance in high temperature environments. The thickness of the elastic copper sheet is reduced to 0.6mm, and the decrease in elastic force caused by the reduction in thickness is compensated by increasing the number of crests of the wavy bend to 5, ensuring that sufficient contact pressure can still be provided in high temperature environments. The material of the sealing ring is changed to fluororubber. Fluororubber has excellent high temperature resistance and chemical corrosion resistance, and can maintain a stable sealing effect in a temperature range of -40℃ to 200℃. A surface treatment process is added to the mating surfaces of the sliding seat and the fixed seat, using hard anodizing to achieve an oxide film thickness of 25μm and a hardness of HV400 or higher. This significantly improves the surface's wear resistance and corrosion resistance, extending the service life of the guiding mechanism. A molybdenum disulfide dry film lubricant is coated onto the mating surfaces of the guide convex strip and the guide groove, with a lubricant layer thickness of 10μm to 15μm. This reduces the sliding friction coefficient, decreases sliding resistance and wear, and improves sliding smoothness, making it particularly suitable for applications with frequent sliding or large displacement. This improved design enables the expansion joint connection structure to operate stably for extended periods in harsh environments with temperatures ranging from -40℃ to +80℃ and relative humidity from 5% to 95%, meeting the requirements of special applications such as offshore platforms, chemical plants, and metallurgical workshops.

[0047] Specifically, the principle of this utility model is as follows: Addressing the problem of radial offset and rotation of the sliding seat in existing busbar expansion joint connection structures, this utility model innovatively designs a sliding guide fit structure where a trapezoidal cross-section guide protrusion and guide groove interlock. The guide protrusion extends axially along the busbar groove and is disposed on the inner wall of the sliding cavity of the fixed seat, while the guide groove is correspondingly disposed on the outer wall of the portion of the sliding seat that extends into the sliding cavity. The guide protrusion and guide groove precisely fit together to form an axial sliding guide pair. The guide rib has a trapezoidal cross-section, with the upper base width smaller than the lower base width. This trapezoidal structure allows the two inclined surfaces of the guide rib to form surface contact with the two inclined surfaces of the groove after the guide rib is embedded in the guide groove. When the sliding seat is subjected to radial force, the normal pressure generated by the inclined surface contact is decomposed into axial and radial components. The angle between the radial component and the normal pressure is determined by the angle of the trapezoid. An appropriate angle makes the radial component significantly greater than the external radial force on the sliding seat, thus generating a self-locking effect and effectively resisting the radial movement of the sliding seat. At the same time, the trapezoidal structure has a large engagement depth, which can effectively prevent the sliding seat from rotating, because any tendency to rotate will increase the interference between the guide rib and the guide groove, generating a large resistance torque. By uniformly distributing multiple guide ribs along the circumference on the inner wall of the sliding cavity, the sliding seat is subjected to balanced constraints in all radial directions, further improving the stability of the guide. The length of the guide ridge is designed to be greater than the sum of the sliding seat's insertion length and the maximum thermal expansion and contraction displacement. This ensures that the guide ridge and guide groove remain engaged throughout the entire operating temperature range, preventing loss of guiding constraint due to excessive displacement. The application of this trapezoidal guide structure enables precise control of the sliding seat's movement trajectory, ensuring the stability of the contact position between the conductive sheet assembly and the sliding seat. This fundamentally solves problems such as poor contact, increased contact resistance, and accelerated wear caused by radial offset and rotation of the sliding seat, thereby improving the reliability and service life of the busbar expansion joint connection structure.

[0048] The specific operation or use method of this utility model is as follows: When installing the busbar system, firstly, the fixed seat is fixedly connected to the end of the first section of the busbar with bolts, and one end of the sliding seat is fixedly connected to the end of the second section of the busbar with bolts. During fixing, it should be ensured that the axes of the fixed seat and the sliding seat are aligned with the axis of the busbar. Then, the end of the sliding seat extending into the sliding cavity is aligned with the inlet of the sliding cavity of the fixed seat, so that the guide groove on the outer wall of the sliding seat is aligned with the guide protrusion on the inner wall of the sliding cavity of the fixed seat. The sliding seat is slowly pushed in axially. The trapezoidal structure of the guide protrusion will automatically guide the guide groove to accurately embed until the annular boss of the sliding seat contacts the stepped surface at the inlet of the sliding cavity of the fixed seat. At this point, the sliding seat reaches the designed insertion depth. During the pushing process, the sealing ring is compressed by the outer wall of the sliding seat, forming a sealing effect. After installation, the free end of the elastic copper sheet of the conductive sheet assembly maintains elastic contact with the outer wall of the sliding seat, establishing an electrical connection path. During the operation of the busbar system, when the ambient temperature rises or the load current increases, causing the busbar temperature to rise, the busbar expands thermally, increasing the distance between the two sections of the busbar. The sliding seat slides axially outward within the sliding cavity of the fixed seat. The engagement of the guide cam and the guide groove guides the sliding seat to slide smoothly axially without radial offset or rotation. The elastic copper sheet undergoes elastic deformation as the sliding seat moves, extending the wavy bend, but the free end of the elastic copper sheet always maintains elastic contact with the outer wall of the sliding seat, maintaining electrical connection. When the temperature decreases, the busbar contracts thermally, and the sliding seat slides axially inward within the sliding cavity of the fixed seat. The entire process is again guided by the engagement of the guide cam and the guide groove, and the wavy bend of the elastic copper sheet contracts, maintaining stable contact. Throughout the entire thermal expansion and contraction cycle, the expansion joint connection structure can automatically adapt to changes in the length of the busbar, maintaining stable electrical and mechanical connections without the need for manual adjustment or maintenance.

Claims

1. A busbar expansion joint connection structure for connecting two busbar sections and accommodating their thermal expansion and contraction, comprising a fixed base, a sliding base, and a conductive plate assembly; the fixed base is bolted to the end of a first busbar section, and a rectangular sliding cavity is formed inside the fixed base; one end of the sliding base is bolted to the end of a second busbar section, and the other end of the sliding base extends into the sliding cavity and is slidably disposed within the sliding cavity along the axial direction of the busbar section; the conductive plate assembly is disposed between the fixed base and the sliding base, for maintaining electrical connection when the sliding base undergoes axial displacement relative to the fixed base; characterized in that, The inner wall of the sliding cavity of the fixed seat is provided with a plurality of guide protrusions extending along the axial direction of the busbar groove. The outer wall of the end of the sliding seat that extends into the sliding cavity is provided with a guide groove that cooperates with the guide protrusions. The guide protrusions and the guide grooves are interlocked to form a sliding guide fit. The cross-section of the guide protrusions is trapezoidal and the width of the upper base of the trapezoid is smaller than the width of the lower base.

2. The expansion joint connection structure for a busbar trunking according to claim 1, characterized in that, The conductive sheet assembly is composed of multiple stacked elastic copper sheets. One end of each elastic copper sheet is fixedly connected to the inner wall of the fixed base, and the other end is a free end that elastically contacts the outer wall of the sliding base.

3. The expansion joint connection structure for a busbar trunking according to claim 2, characterized in that, The length of the guide convex strip along the axial direction of the busbar groove is greater than the sum of the length of the portion of the sliding seat extending into the sliding cavity along the axial direction of the busbar groove and the maximum thermal expansion and contraction displacement of the busbar groove.

4. The expansion joint connection structure for a busbar trunking according to claim 3, characterized in that, The width ratio of the upper base to the lower base of the trapezoidal cross-section of the guide protrusion is 1:2.5 to 1:1.5, and the cross-sectional shape of the guide groove is adapted to the trapezoidal cross-section of the guide protrusion.

5. The expansion joint connection structure for a busbar trunking according to claim 4, characterized in that, The sliding cavity of the fixed seat has four guide protrusions evenly distributed circumferentially on its inner wall, and the outer wall of the sliding seat has four guide grooves correspondingly provided.

6. The expansion joint connection structure for a busbar trunking according to claim 5, characterized in that, An annular boss is provided on the outer wall of the end of the sliding seat that extends into the sliding cavity. The outer diameter of the annular boss is smaller than the inner diameter of the sliding cavity and larger than the outer diameter of the sliding seat body. The annular boss is located between the guide groove and the end face of the sliding seat.

7. The expansion joint connection structure for a busbar trunking according to claim 6, characterized in that, A sealing ring is provided between the mating surfaces of the fixed seat and the sliding seat. The sealing ring is embedded in an annular sealing groove provided at the entrance of the sliding cavity of the fixed seat. The inner diameter of the sealing ring is smaller than the outer diameter of the extended portion of the sliding seat.

8. The expansion joint connection structure for a busbar trunking according to claim 7, characterized in that, Both the fixed base and the sliding base are made of aluminum alloy, and the elastic copper sheet of the conductive sheet assembly is made of phosphor bronze.

9. The expansion joint connection structure of a busbar trunking according to claim 8, characterized in that, The sliding cavity of the fixed seat has a rectangular cylindrical structure, and the end of the sliding seat that extends into the sliding cavity has a rectangular columnar structure that is adapted to the sliding cavity.

10. The expansion joint connection structure of a busbar trunking according to claim 9, characterized in that, Each of the elastic copper sheets has a wavy bend between its fixed end and free end. The wavy bend includes at least two peaks and troughs arranged along the axial direction of the busbar groove. The free end of the elastic copper sheet is bent toward the outer wall of the sliding seat to form a contact protrusion.

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