Feedthrough connector

Abstract

The invention relates to the technical field of electric connectors, in particular to a feed-through connector which comprises a feed-through insertion piece, a coaxial cable, a coaxial connector with the characteristic impedance of 50 ohms, an epoxy resin sealing layer and a connecting plug. The feed-through insertion piece is made of an insulating high-molecular polymer material and comprises an installation body, the installation body is provided with a first side and a second side which are oppositely arranged in the axial direction, an installation channel penetrating in the axial direction is formed in the installation body, and a plurality of bolt holes are formed in the installation body; the mounting channel comprises a first hole section and a second hole section which are sequentially communicated in the axial direction, the hole diameter of the first hole section is larger than that of the second hole section, and the connecting plug is fixedly arranged on the first side of the mounting body and coaxially and correspondingly arranged with the mounting channel; and stable coaxial transmission and sealing insulation effects can be realized while the mechanical connection reliability is maintained.

Description

Technical Field

[0001] This invention relates to the field of electrical connector technology, and more particularly to a feedthrough connector. Background Technology

[0002] Feedthrough connectors are electrical connection devices installed at openings in partition walls, bulkheads, hull walls, or other structures to transmit electrical signals or energy from one side of the structure to the other, while maintaining the sealing and insulation of the installation site as much as possible during transmission. In applications using coaxial signal transmission, feedthrough connectors are typically used in conjunction with coaxial cables, coaxial connectors, or plugs to form a continuous coaxial transmission path. They are widely used in underwater equipment, sealed hulls, pressure-resistant equipment, and other devices requiring through-wall conductive connections.

[0003] While conventional electrical connectors can achieve conductive connections, they often struggle to simultaneously meet requirements for installation fixation, sealing insulation, and high-frequency coaxial transmission when installed in structural openings and serving as through-wall conductive connections. This is especially true when using coaxial structures to transmit high-frequency signals. In addition to requiring a reliable electrical connection between the connector's center and outer conductors, a stable coaxial structure and impedance matching at the connection interface are also essential to minimize signal reflection and transmission loss.

[0004] In addition, in underwater or pressurized environments, after the feedthrough connector is installed at the structural opening, it is also necessary to consider the installation stability, local sealing and holding capacity, and insulation reliability during long-term use. Some existing through-wall connection structures still have the following shortcomings: (1) The matching structure between the installation body and the external installation interface is relatively simple, and the fixing strength and overall installation stability are insufficient; (2) When the cable passes through the structural opening, the local sealing structure and the insulation support structure are not tightly matched, making it difficult to form a long-term stable sealed insulation interface; (3) The continuity of the connection transition structure between the coaxial cable and the coaxial connector or plug is insufficient, which is not conducive to maintaining stable characteristic impedance and high-frequency transmission performance; (4) Some existing structures are difficult to simultaneously meet the electrical index requirements such as low contact resistance, high insulation resistance, and withstand voltage performance; (5) The conductor connection method at the connection end is relatively simple, and the structural transition between the center conductor and the outer conductor in the connection area is not reasonable enough, which can easily affect the connection reliability and coaxial transmission consistency.

[0005] Therefore, existing technologies still require a feedthrough connector to address the shortcomings of through-wall conductive connection structures in terms of installation stability, sealing and insulation performance, and high-frequency coaxial signal transmission performance. Summary of the Invention

[0006] To at least solve one of the aforementioned technical problems in the prior art, the present invention aims to provide a feedthrough connector.

[0007] The objective of this invention is achieved as follows:

[0008] A feedthrough connector includes a feedthrough insert, a coaxial cable, a coaxial connector with a characteristic impedance of 50Ω, an epoxy resin sealing layer, and a plug. The feedthrough insert is made of an insulating polymer material and includes a mounting body. The mounting body has a first side and a second side arranged opposite each other along an axial direction. An axially penetrating mounting channel is provided within the mounting body, and the mounting body has multiple bolt holes. The mounting channel includes a first hole segment and a second hole segment connected sequentially along an axial direction. The diameter of the first hole segment is larger than the diameter of the second hole segment. The plug is fixedly disposed on the first side of the mounting body and coaxially corresponding to the mounting channel. The coaxial cable passes through the mounting channel and includes an inner conductor and a sheath covering... The inner conductor has an insulating dielectric layer around its periphery and an outer conductor covering the outer periphery of the insulating dielectric layer; one end of the coaxial cable passes sequentially from the second side of the mounting body to the first side through the second hole segment and the first hole segment and is connected to the connector; the inner wall of the second hole segment and the outer periphery of the coaxial cable are filled with the epoxy resin sealing layer, and the epoxy resin sealing layer forms a sealed retaining section around the coaxial cable after curing; the coaxial connector is located at the other end of the coaxial cable and is located on the second side of the mounting body; the coaxial connector includes a center contact and an outer contact; the center contact is electrically connected to the inner conductor, the outer contact is electrically connected to the outer conductor, and the center contact and the outer contact are coaxially arranged.

[0009] By setting up a feedthrough insert, coaxial cable, coaxial connector, epoxy resin sealing layer and plug, and passing the coaxial cable through the installation channel in the mounting body, the feedthrough connector can form a stable sealed and fixed structure at the installation location while realizing electrical connection at both ends. This solves the problems of single installation form, insufficient sealing and insulation performance and discontinuous high-frequency coaxial signal transmission path in the existing through-wall connection structure. It is beneficial to achieve more stable coaxial transmission and sealing and insulation effect while maintaining the reliability of mechanical connection.

[0010] The objective of this invention can also be achieved by the following technical measures:

[0011] Furthermore, an annular gap is formed between the inner wall of the second hole segment and the outer periphery of the coaxial cable, and the epoxy resin sealing layer fills the annular gap.

[0012] By defining an annular gap between the inner wall of the second hole section and the outer periphery of the coaxial cable, and filling the annular gap with epoxy resin sealing layer, the sealing material has a clear filling space and distribution position in the installation channel. This solves the problems of unclear filling area and poor potting consistency of the sealing material in the prior art, which is conducive to improving the adhesion between the sealing layer and the coaxial cable and improving the sealing stability of the penetration part.

[0013] Furthermore, the feedthrough insert and the epoxy resin sealing layer together form a through-wall sealing insulation structure around the coaxial cable.

[0014] By defining the feedthrough insert and the epoxy resin sealing layer to form a through-wall sealed insulation structure around the coaxial cable, a synergistic relationship is formed between the installation body, the cable and the sealing layer. This solves the problem of the separation of the sealing structure and the insulation support structure and the lack of overall integrity in the existing through-wall connection structure. It is beneficial to further improve the insulation reliability and sealing integrity of the installation part in addition to the conductive connection.

[0015] Furthermore, an annular transition step is formed between the first hole segment and the second hole segment, and the epoxy resin sealing layer is disposed against the annular transition step to form a sealing and retaining segment with restricted axial position.

[0016] By setting an annular transition step between the first and second hole sections and placing the epoxy resin sealing layer against the annular transition step, the axial position of the sealing layer is restricted, which solves the problems of difficult control of the sealing layer potting range and insufficient positional stability after curing in the prior art. This is beneficial to improving the molding consistency of the sealing retention section and enhancing the structural reliability of the penetration area.

[0017] Furthermore, the epoxy resin sealing layer is integrally bonded to the inner wall of the second hole segment and the outer periphery of the coaxial cable.

[0018] By integrating the epoxy resin sealing layer with the inner wall of the second hole section and the outer periphery of the coaxial cable, the sealing layer not only serves as a simple filler but also forms an integral structure with the installation channel and cable. This solves the problem of the existing sealing layer not being firmly bonded to the structural components and being prone to loosening or failure during long-term use, which is conducive to further improving the sealing strength and overall stability of the penetration area.

[0019] Furthermore, the coaxial connector is an RF coaxial connector, the characteristic impedance of the coaxial cable is 50Ω, the maximum contact resistance of the feedthrough connector is no greater than 20mΩ, the insulation resistance is no less than 1000MΩ, and the withstand voltage time at 150Vac is 30 seconds.

[0020] By defining the coaxial connector as an RF coaxial connector and further defining the electrical properties of the coaxial cable, such as impedance, contact resistance, insulation resistance, and withstand voltage, the problem that existing through-wall connection structures cannot simultaneously meet the requirements of high-frequency transmission and basic electrical performance is solved. This helps to ensure that the feedthrough connector has good conductivity, insulation performance, and withstand voltage in high-frequency application scenarios.

[0021] Furthermore, the characteristic impedance Z0 of the coaxial transmission structure formed by the coaxial cable and the coaxial connector satisfies the formula: Z0=(138 / √εr)lg(D / d), where εr represents the relative permittivity of the insulating dielectric layer, D represents the inner diameter of the outer conductor, d represents the outer diameter of the inner conductor, and Z0 is 50Ω.

[0022] By introducing the calculation formula for the characteristic impedance of the coaxial transmission structure and clearly defining the parameters of the insulating dielectric layer and the relationship between the dimensions of the inner and outer conductors, the problems of lack of clear basis for impedance matching design and unstable high-frequency transmission performance in the connection area in the existing connection structure are solved. This is beneficial to control the impedance continuity of the connection area in the design stage and reduce signal reflection and transmission loss.

[0023] Furthermore, the inner conductor is a stranded conductor formed by twisting multiple conductive single wires, wherein the conductive single wires are copper single wires or copper alloy single wires, and the outer periphery of the inner conductor is provided with a conductive plating layer, wherein the conductive plating layer is a silver plating layer or a tin plating layer; a stepped stripping section is formed at one end of the coaxial cable near the coaxial connector, so that the inner conductor, the insulating dielectric layer and the outer conductor form sequentially staggered connection sections along the axial direction; the central contact is provided with a central connecting part connected to the inner conductor, and the outer contact is provided with an outer connecting part connected to the outer conductor, wherein the central connecting part is fixedly connected to the inner conductor, and the outer connecting part is fixedly connected to the outer conductor.

[0024] By defining the stranding form of the inner conductor, the material of the conductive monofilament, the plating form, and the stepped stripping section and connection section, the problems of simple conductor structure, unreasonable connection transition, and insufficient connection stability of the existing connection end are solved. This is beneficial to improving the flexibility and conductivity of the inner conductor and forming a clearer transition connection structure between the cable end and the connector.

[0025] Furthermore, the central connecting part is a sleeve-type contact structure, the outer connecting part is a ring-type contact structure, and the central connecting part and the outer connecting part are arranged radially spaced apart; the central connecting part is correspondingly clamped on the outer periphery of the inner conductor, and the outer connecting part is correspondingly covered on the outer periphery of the outer conductor, so as to form a continuous coaxial connection interface between the coaxial connector and the coaxial cable.

[0026] By defining the central connection part as a sleeve-type contact structure and the outer connection part as a ring-shaped contact structure, and setting the two at radial intervals, the problem of unclear distinction between the internal and external conductive paths and insufficient continuity of the connection interface in existing coaxial connection ends is solved. This is conducive to forming a more stable coaxial connection interface between the coaxial connector and the coaxial cable, further improving connection reliability and high-frequency transmission consistency.

[0027] Furthermore, the inner wall of the second hole section is provided with at least one annular limiting groove or annular consolidation recess extending circumferentially. The epoxy resin sealing layer partially fills the annular limiting groove or annular consolidation recess and forms an axial limiting structure for the coaxial cable after curing.

[0028] By setting an annular limiting groove or annular consolidation recess on the inner wall of the second hole section and filling it with epoxy resin sealing layer, the cured sealing layer forms an axial limiting structure for the coaxial cable. This solves the problem that the existing sealing layer is not strong enough to resist pull-out because it only relies on surface adhesion. It is beneficial to improve the mechanical locking effect between the sealing layer and the installation body and enhance the overall vibration resistance and pull-out resistance.

[0029] Furthermore, the annular transition step and the second hole segment together define a local potting and sealing area, and the epoxy resin sealing layer is disposed within the local potting and sealing area.

[0030] By having the annular transition step and the second hole section jointly define the local potting sealing area, the epoxy resin sealing layer is concentrated in this local area, thus solving the problems of unclear potting area boundaries and difficulty in controlling the distribution range of sealing materials in the prior art. This is beneficial to improving the consistency of the potting process and improving the stability and controllability of the local sealing structure.

[0031] Furthermore, the coaxial cable near the coaxial connector has a multi-stage stepped stripping structure, so that the inner conductor, the insulating dielectric layer and the outer conductor form sequentially staggered connection sections along the axial direction, wherein the exposed length of the inner conductor is less than the exposed length of the insulating dielectric layer, and the exposed length of the insulating dielectric layer is less than the exposed length of the outer conductor.

[0032] By setting a multi-stage stepped stripping structure at one end of the coaxial cable near the coaxial connector and defining the corresponding exposed length relationship of the inner conductor, insulating dielectric layer and outer conductor, the problem of large abrupt transitions in the existing connection end structure, which is not conducive to forming a stable connection section, is solved. This is beneficial to make each layer of the structure transition gradually along the axial direction, and improve the structural rationality and coaxial continuity of the connection area.

[0033] Furthermore, the central connecting part is a sleeve-type conductive connecting part extending along the axial direction. The sleeve-type conductive connecting part is sleeved on the outer periphery of the exposed part of the inner conductor and is pressed and fixed or welded to the inner conductor.

[0034] By defining the central connection part as a sleeve-type conductive connection part extending along the axial direction, and fixing it to the exposed part of the inner conductor by pressing or welding, the problems of small contact area and insufficient fixing reliability of the existing inner conductor connection end are solved, which is conducive to improving the mechanical stability and electrical connection reliability of the central conductive path.

[0035] Furthermore, the outer connecting part is a circumferentially encircling conductive connecting part, which covers the outer periphery of the exposed portion of the outer conductor and is pressed or welded to the outer conductor.

[0036] By defining the outer connection part as a circumferentially enclosing conductive connection part and fixing it after covering the exposed part of the outer conductor, the problems of insufficient coverage of the existing outer conductor connection area and unstable grounding path are solved. This is beneficial to enhance the coverage continuity and connection strength of the outer conductor connection area and improve the stability of the outer conductive path.

[0037] Furthermore, the central connecting portion and the outer connecting portion are radially spaced apart, and the corresponding areas between them are separated by the exposed portion of the insulating dielectric layer, so as to form a continuous coaxial connection interface between the coaxial connector and the coaxial cable.

[0038] By defining the radial spacing between the central connecting part and the outer connecting part, and separating the corresponding areas by the exposed portion of the insulating dielectric layer, the problem of unclear boundaries between the inner and outer conductive parts in the existing connecting area, which easily affects the stability of the coaxial connection interface, is solved. This is conducive to forming a more continuous and clear coaxial structure in the connecting area, thereby improving high-frequency transmission performance.

[0039] Furthermore, after the outer connecting portion covers the exposed portion of the outer conductor, it together with the outer conductor to form a ring-shaped conductive connection structure.

[0040] By defining the outer connection part to cover the exposed part of the outer conductor and forming a ring-shaped conductive connection structure together with the outer conductor, the problems of discontinuous conductive path and incomplete grounding ring structure in the existing outer conductor connection area are solved. This helps to improve the continuity of the outer conductive path and further enhance the stability and shielding effect of the coaxial connection interface.

[0041] The beneficial effects of this invention are as follows:

[0042] This invention provides a feedthrough insert, a coaxial cable, a coaxial connector, a plug, and an epoxy resin sealing layer. The coaxial cable is inserted into the mounting channel of the mounting body, and a sealed retaining section is formed at the second hole. This allows the feedthrough connector to achieve electrical connection at both ends while forming a relatively stable sealed insulation structure at the mounting location. This improves the problems of insufficient installation stability, poor sealing, and low insulation reliability in existing through-wall connection structures.

[0043] This invention provides a first hole segment and a second hole segment that are sequentially connected along the axial direction within the mounting body. A gap for filling an epoxy resin sealing layer is formed between the inner wall of the second hole segment and the outer periphery of the coaxial cable. Preferably, an annular transition step is provided between the first hole segment and the second hole segment. This makes it easier to control the distribution range and axial position of the sealing layer within the mounting channel, which is beneficial to improving the consistency of the potting area and the stability of the sealing and holding structure, and further enhancing the reliability of the feedthrough connector during long-term use.

[0044] This invention integrates the epoxy resin sealing layer with the inner wall of the second hole section and the outer periphery of the coaxial cable, and forms a through-wall sealing and insulating structure with the feedthrough insert and the epoxy resin sealing layer around the coaxial cable. This allows the sealing layer to not only fill the gap, but also form an integral fit with the installation body and the cable, which is beneficial to improving the local sealing strength, the overall structural stability, and the sealing and insulation performance during long-term use.

[0045] This invention places a coaxial connector at one end of a coaxial cable, connects the center contact to the inner conductor and the outer contact to the outer conductor, and forms a continuous coaxial transmission structure through the coaxial arrangement of the center and outer contacts. This helps maintain the continuity of the coaxial path in the connection area, reduces structural abrupt changes at the connection interface, reduces reflection and loss during high-frequency signal transmission, and thus improves the performance of high-frequency signal transmission.

[0046] This invention defines the structure, material, and plating of the inner conductor, and combines the stepped stripping section, the central connection part, and the outer connection part to form a more reasonable connection transition structure between the coaxial cable and the coaxial connector. Furthermore, by adopting a sleeve-type contact structure and a wrap-around contact structure, a continuous coaxial connection interface can be formed between the coaxial connector and the coaxial cable, which is beneficial to improving the mechanical reliability, conductivity stability, and high-frequency transmission consistency of the connection end.

[0047] This invention designs the coaxial transmission structure, consisting of a coaxial cable and a coaxial connector, to meet the 50Ω characteristic impedance requirement. Through the matching design of the relative permittivity of the insulating dielectric layer and the dimensions of the inner and outer conductors, the connection area has a clear impedance design basis, which helps to reduce impedance mismatch and improve signal transmission stability. Simultaneously, by combining requirements for maximum contact resistance, insulation resistance, and withstand voltage, the feedthrough connector can simultaneously achieve conductivity, insulation, and withstand voltage performance, making it more suitable for underwater equipment, sealed equipment, and other applications requiring high-frequency signal transmission through walls. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of a feedthrough connector (with the coaxial cable and feedthrough insert separated).

[0049] Figure 2 This is a schematic diagram of the feedthrough connector from another angle (with the coaxial cable and feedthrough insert separated).

[0050] Figure 3 This is a top view of the feedthrough connector (with the coaxial cable and feedthrough insert separated).

[0051] Figure 4 This is a cross-sectional view of the feedthrough connector.

[0052] Figure 5 for Figure 4 Enlarged view of part A.

[0053] Figure 6 A partial cross-sectional view showing the connection status of the feedthrough connector and coaxial cable.

[0054] Figure 7 This is a schematic diagram of the assembly of a coaxial cable and a coaxial connector.

[0055] Figure 8 This is a schematic diagram of a coaxial cable and coaxial connector assembly. Detailed Implementation

[0056] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0057] Example 1, such as Figures 1 to 8 As shown, this embodiment provides a feedthrough connector, including a feedthrough insert 1, a coaxial cable 2, a coaxial connector 3 with a characteristic impedance of 50Ω, an epoxy resin sealing layer 4, and a plug 5.

[0058] The feedthrough insert 1 is made of an insulating polymer material. The feedthrough insert 1 includes a mounting body 11, which has a first side 111 and a second side 112 arranged axially opposite each other. The mounting body 11 has an axially penetrating mounting channel 12 and a plurality of bolt holes 13. Preferably, the plurality of bolt holes 13 are spaced apart circumferentially along the mounting body 11 to facilitate the fixed installation of the feedthrough insert 1 using bolts.

[0059] The mounting channel 12 includes a first hole segment 121 and a second hole segment 122 connected sequentially along the axial direction, wherein the diameter of the first hole segment 121 is larger than the diameter of the second hole segment 122. Preferably, an annular transition step 123 is formed between the first hole segment 121 and the second hole segment 122. The connector 5 is fixedly disposed on the first side 111 of the mounting body 11, and is connected to and coaxially corresponding to the first hole segment 121. Preferably, the connector 5 includes a signal plug-in portion and a ground connection portion, which are arranged radially spaced apart.

[0060] The coaxial cable 2 is inserted into the installation channel 12. The coaxial cable 2 includes an inner conductor 21, an insulating dielectric layer 22 covering the outer periphery of the inner conductor 21, and an outer conductor 23 covering the outer periphery of the insulating dielectric layer 22. Preferably, the inner conductor 21 is a stranded conductor formed by twisting multiple conductive single wires, wherein the conductive single wires are copper single wires or copper alloy single wires. Preferably, the outer periphery of the inner conductor 21 is provided with a conductive plating layer, wherein the conductive plating layer is a silver plating layer or a tin plating layer, to improve conductivity and enhance connection reliability.

[0061] One end of the coaxial cable 2 passes sequentially from the second side 112 of the mounting body 11 to the first side 111, through the second hole section 122 and the first hole section 121, and then connects to the connector 5. An annular gap is formed between the inner wall of the second hole section 122 and the outer periphery of the coaxial cable 2, and the epoxy resin sealing layer 4 fills the annular gap. Preferably, the epoxy resin sealing layer 4 abuts against the annular transition step 123 to form a sealed retaining section with restricted axial position. After curing, the epoxy resin sealing layer 4 forms a sealed retaining section surrounding the coaxial cable 2 and is integrally bonded to the inner wall of the second hole section 122 and the outer periphery of the coaxial cable 2, thereby forming a through-wall sealed insulation structure around the coaxial cable 2 with the feedthrough insert 1 and the epoxy resin sealing layer 4.

[0062] The coaxial connector 3 is located at the other end of the coaxial cable 2 and on the second side 112 of the mounting body 11. The coaxial connector 3 is preferably an RF coaxial connector with a characteristic impedance of 50Ω. The coaxial connector 3 includes a center contact 31 and an outer contact 32. The center contact 31 is electrically connected to the inner conductor 21, and the outer contact 32 is electrically connected to the outer conductor 23. The center contact 31 and the outer contact 32 are coaxially arranged to form a continuous coaxial transmission structure.

[0063] The coaxial cable 2 near the coaxial connector 3 forms a stepped stripping section 24, so that the inner conductor 21, the insulating dielectric layer 22, and the outer conductor 23 form sequentially staggered connection sections along the axial direction. The center contact 31 has a center connecting portion 311 connected to the inner conductor 21, and the outer contact 32 has an outer connecting portion 321 connected to the outer conductor 23. The center connecting portion 311 is fixedly connected to the inner conductor 21, and the outer connecting portion 321 is fixedly connected to the outer conductor 23. Preferably, the center connecting portion 311 is a sleeve-type contact structure, correspondingly clamped on the outer periphery of the inner conductor 21; the outer connecting portion 321 is a wrap-around contact structure, correspondingly covering the outer periphery of the outer conductor 23; the center connecting portion 311 and the outer connecting portion 321 are arranged radially spaced to form a continuous coaxial connection interface between the coaxial connector 3 and the coaxial cable 2.

[0064] In this embodiment, the maximum contact resistance of the feedthrough connector is no greater than 20mΩ, the insulation resistance is no less than 1000MΩ, and the withstand voltage time at 150Vac is 30 seconds.

[0065] In this embodiment 1, the coaxial cable 2 and the coaxial connector 3 constitute a coaxial transmission structure, and the characteristic impedance Z0 of this coaxial transmission structure satisfies the following formula:

[0066] Z0=(138 / √εr)lg(D / d)

[0067] In this formula, Z0 represents the characteristic impedance of the coaxial transmission structure in ohms; εr represents the relative permittivity of the insulating dielectric layer 22; D represents the inner diameter of the outer conductor 23; d represents the outer diameter of the inner conductor 21; and lg represents the common logarithm to base 10. In this formula, D and d use the same unit of length, such as millimeters, and D / d is dimensionless. By adjusting the permittivity εr of the insulating dielectric layer 22 and the ratio between the outer diameter d of the inner conductor 21 and the inner diameter D of the outer conductor 23, the coaxial transmission structure can achieve the required 50Ω characteristic impedance, thereby reducing reflection loss and improving high-frequency transmission stability.

[0068] The examples below are only used to illustrate the application of the above formulas and do not constitute a limitation of the present invention.

[0069] Assuming the relative permittivity εr of the insulating dielectric layer 22 is 2.25, then √εr = 1.5. If the desired characteristic impedance Z0 of the coaxial transmission structure is 50Ω, then according to the above formula, 50 = (138 / 1.5)lg(D / d), that is, 50 = 92lg(D / d). Therefore, lg(D / d) = 50 / 92 ≈ 0.543, and further, D / d ≈ 10^0.543 ≈ 3.49. That is, the ratio of the inner diameter D of the outer conductor 23 to the outer diameter d of the inner conductor 21 is preferably about 3.49. For example, when the outer diameter d of the inner conductor 21 is 0.90mm, then the inner diameter D of the outer conductor 23 can be taken as about 3.14mm. Under this set of parameters, the theoretical characteristic impedance of the coaxial transmission structure is close to 50Ω.

[0070] For another example, if the insulating dielectric layer 22 is made of a material with a relative permittivity εr of 2.10, then √εr≈1.449. When Z0 is 50Ω, we have: 50=(138 / 1.449)lg(D / d), that is, 50≈95.24lg(D / d). From this, we can get lg(D / d)≈0.525, therefore D / d≈10^0.525≈3.35. It can be seen that when the insulating dielectric material changes, in order to maintain a characteristic impedance of 50Ω, the ratio of D to d should also be adjusted accordingly.

[0071] The feedthrough connector in this embodiment can be used in applications that require high-frequency signal transmission through walls, especially suitable for underwater equipment, sealed chambers, pressure-resistant equipment, or other applications that require both sealing insulation and high-frequency coaxial transmission performance at the mounting interface.

[0072] Based on Embodiment 1, the feedthrough connector in Embodiment 2 further adopts the following structure.

[0073] Furthermore, an annular transition step 123 is formed between the first hole segment 121 and the second hole segment 122. The epoxy resin sealing layer 4 is disposed against the annular transition step 123 to form a sealing and retaining segment with restricted axial position. Through the limiting effect of the annular transition step 123, the epoxy resin sealing layer 4 can maintain a stable axial position after curing, thereby improving the consistency and reliability of the sealing and retaining structure.

[0074] Furthermore, an annular gap is formed between the inner wall of the second hole segment 122 and the outer periphery of the coaxial cable 2. The epoxy resin sealing layer 4 fills the annular gap and is solidified together with the inner wall of the second hole segment 122 and the outer periphery of the coaxial cable 2, thereby forming a local sealing and insulating structure at the second hole segment 122.

[0075] Furthermore, the inner wall of the second hole segment 122 is provided with at least one annular limiting groove or annular consolidation recess extending in the circumferential direction. The epoxy resin sealing layer 4 is partially filled in the annular limiting groove or annular consolidation recess and forms an axial limiting structure for the coaxial cable 2 after curing.

[0076] Furthermore, the coaxial cable 2 near the coaxial connector 3 has a multi-stage stepped stripping structure, so that the inner conductor 21, the insulating dielectric layer 22, and the outer conductor 23 form sequentially staggered connection sections along the axial direction. The exposed length of the inner conductor 21 is less than the exposed length of the insulating dielectric layer 22, and the exposed length of the insulating dielectric layer 22 is less than the exposed length of the outer conductor 23. This structure reduces geometric abrupt changes at the connection end and improves the continuity of the coaxial connection interface.

[0077] Furthermore, the central connecting portion 311 is an axially extending sleeve-type conductive connecting portion, which is sleeved around the exposed portion of the inner conductor 21 and is pressed and fixed to the inner conductor 21 by crimping or welding. The outer connecting portion 321 is a circumferentially surrounding an encircling conductive connecting portion, which covers the exposed portion of the outer conductor 23 and is pressed and fixed to the outer conductor 23 by crimping or welding. Thus, the central connecting portion 311 and the outer connecting portion 321 form a stable connection on the inner and outer conductive paths, respectively, thereby improving the mechanical reliability and conductive stability of the connection ends.

[0078] Furthermore, the central connecting portion 311 and the outer connecting portion 321 are radially spaced apart, and their corresponding areas are separated by the exposed portion of the insulating dielectric layer 22, thereby forming a continuous coaxial connection interface between the coaxial connector 3 and the coaxial cable 2. Preferably, after the outer connecting portion 321 covers the exposed portion of the outer conductor 23, it forms an annular conductive connection structure together with the outer conductor 23; the central connecting portion 311, the exposed portion of the insulating dielectric layer 22, and the outer connecting portion 321 are arranged radially from the inside to the outside in sequence to maintain the continuity of the coaxial transmission structure at the connection end.

[0079] Furthermore, in the connection transition area between the coaxial connector 3 and the coaxial cable 2, the equivalent coaxial structure of the connection transition area is formed by the equivalent outer diameter dt of the area corresponding to the central connection part 311, the equivalent inner diameter Dt of the area corresponding to the outer connection part 321, and the equivalent relative permittivity εrt located between the two. The equivalent characteristic impedance Zt of the connection transition area satisfies the following formula:

[0080] Zt=(138 / √εrt)lg(Dt / dt)

[0081] Where Zt represents the equivalent characteristic impedance of the connection transition region, εrt represents the equivalent relative permittivity of the insulating region of the connection transition region, Dt represents the equivalent inner diameter of the region corresponding to the outer connecting part 321, and dt represents the equivalent outer diameter of the region corresponding to the central connecting part 311. Preferably, by adjusting the outer diameter of the central connecting part 311, the inner diameter of the outer connecting part 321, and the geometric dimensions and dielectric parameters of the insulating region between them, the equivalent characteristic impedance Zt of the connection transition region is matched to or close to 50Ω. This formula is used for the size matching design of the connection transition region, thereby reducing the impedance abrupt change in the connection area between the coaxial cable 2 and the coaxial connector 3, and improving the stability of high-frequency signal transmission.

[0082] Furthermore, the connector 5 includes a signal insertion portion and a grounding connection portion, which are radially spaced and coaxially arranged. The inner conductor 21 of the coaxial cable 2 at one end of the first side 111 is connected to the signal insertion portion, and the outer conductor 23 is connected to the grounding connection portion, thereby forming a continuous coaxial connection structure at the end of the coaxial cable 2 near the connector 5. Through the above arrangement, a continuous or nearly continuous coaxial transmission path can be formed from the connector 5 side to the coaxial connector 3 side of the feedthrough connector.

[0083] In this embodiment, the epoxy resin sealing layer 4, the feedthrough insert 1, and the coaxial cable 2 together form an integrated sealed insulation unit; the plug 5, the coaxial cable 2, and the coaxial connector 3 together form a coaxial electrical connection unit penetrating the mounting body 11. Therefore, after installation, the feedthrough connector can form both a stable sealed insulation structure and a continuous coaxial electrical connection interface.

Claims

1. A feedthrough connector, characterized in that, Includes feedthrough inserts, coaxial cables, coaxial connectors with a characteristic impedance of 50Ω, epoxy resin sealing layers, and plugs; The feedthrough insert is made of an insulating polymer material. The feedthrough insert includes a mounting body, which has a first side and a second side arranged opposite to each other along the axial direction. The mounting body has an axially penetrating mounting channel and multiple bolt holes. The installation channel includes a first hole segment and a second hole segment connected sequentially along the axial direction. The diameter of the first hole segment is larger than the diameter of the second hole segment. The plug is fixedly disposed on the first side of the installation body and is coaxially corresponding to the installation channel. The coaxial cable is installed in the installation channel. The coaxial cable includes an inner conductor, an insulating dielectric layer covering the outer periphery of the inner conductor, and an outer conductor covering the outer periphery of the insulating dielectric layer. One end of the coaxial cable passes through the second hole and the first hole in sequence from the second side to the first side of the mounting body and is then connected to the plug. The inner wall of the second hole and the outer periphery of the coaxial cable are filled with the epoxy resin sealing layer. After the epoxy resin sealing layer is cured, it forms a sealed retaining section around the coaxial cable. The coaxial connector is located at the other end of the coaxial cable and on the second side of the mounting body. The coaxial connector includes a center contact and an outer contact. The center contact is electrically connected to the inner conductor, and the outer contact is electrically connected to the outer conductor. The center contact and the outer contact are coaxially arranged.

2. The feedthrough connector according to claim 1, characterized in that, An annular gap is formed between the inner wall of the second hole section and the outer periphery of the coaxial cable, and the epoxy resin sealing layer fills the annular gap.

3. The feedthrough connector according to claim 1 or 2, characterized in that, The feedthrough insert and the epoxy resin sealing layer together form a through-wall sealing insulation structure around the coaxial cable.

4. The feedthrough connector according to claim 2, characterized in that, An annular transition step is formed between the first hole segment and the second hole segment, and the epoxy resin sealing layer is disposed against the annular transition step to form a sealing and retaining segment with restricted axial position.

5. The feedthrough connector according to claim 1, characterized in that, The epoxy resin sealing layer is integrally bonded to the inner wall of the second hole section and the outer periphery of the coaxial cable.

6. The feedthrough connector according to claim 1, characterized in that, The coaxial connector is an RF coaxial connector, the characteristic impedance of the coaxial cable is 50Ω, the maximum contact resistance of the feedthrough connector is no greater than 20mΩ, the insulation resistance is no less than 1000MΩ, and the withstand voltage time at 150Vac is 30 seconds.

7. The feedthrough connector according to claim 6, characterized in that, The characteristic impedance Z0 of the coaxial transmission structure formed by the coaxial cable and the coaxial connector satisfies the formula: Z0=(138 / √εr)lg(D / d), Where εr represents the relative permittivity of the insulating dielectric layer, D represents the inner diameter of the outer conductor, d represents the outer diameter of the inner conductor, and Z0 is 50Ω.

8. The feedthrough connector according to claim 1, characterized in that, The inner conductor is a stranded conductor formed by twisting multiple conductive single wires, wherein the conductive single wires are copper single wires or copper alloy single wires, and the outer periphery of the inner conductor is provided with a conductive plating layer, wherein the conductive plating layer is a silver plating layer or a tin plating layer; the coaxial cable has a stepped stripping section at one end near the coaxial connector, so that the inner conductor, the insulating dielectric layer and the outer conductor form a sequentially staggered connection section along the axial direction; the center contact has a center connecting part connected to the inner conductor, and the outer contact has an outer connecting part connected to the outer conductor, wherein the center connecting part is fixedly connected to the inner conductor and the outer connecting part is fixedly connected to the outer conductor.

9. The feedthrough connector according to claim 8, characterized in that, The central connecting part is a sleeve-type contact structure, and the outer connecting part is a ring-type contact structure. The central connecting part and the outer connecting part are arranged radially spaced apart. The central connecting part is correspondingly clamped on the outer periphery of the inner conductor, and the outer connecting part is correspondingly covered on the outer periphery of the outer conductor, so as to form a continuous coaxial connection interface between the coaxial connector and the coaxial cable.

10. The feedthrough connector according to claim 2, characterized in that, The inner wall of the second hole section is provided with at least one annular limiting groove or annular consolidation recess extending in the circumferential direction. The epoxy resin sealing layer partially fills the annular limiting groove or annular consolidation recess and forms an axial limiting structure for the coaxial cable after curing.

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