Armoured, crevice self-pumping, lubricated, corrosion resistant control cable and method of manufacture and control

Abstract

The present application relates to a kind of armored gap self-pumping lubricated corrosion-resistant control cable, manufacturing and control method, cable includes cable core, first inner sheath, corrugated metal buffer cover, lead alloy sheath, second inner sheath in turn from inside to outside;Annular gap between inner armor and outer armor;The lubricating medium layer filled in the annular gap, fluid pumping structure is arranged in the annular gap and is in contact with the lubricating medium layer, fluid pumping structure generates pumping pressure for driving lubricating medium to flow along the cable axial direction in response to the bending deformation of cable.The present application armored gap self-pumping lubricated corrosion-resistant control cable and manufacturing and control method, armored gap long-acting active corrosion protection, by fluid pumping structure, using cable itself mechanical movement, capillary force as driving force, make lubricating medium continue to circulate in armored gap Flow, avoid the problem of traditional static lubricating medium dryness failure.

Description

Technical Field

[0001] This invention relates to the field of cable manufacturing technology, and more specifically, to an armored, gap-sealed, self-pumping, lubricating, corrosion-resistant control cable and its manufacturing and control methods. Background Technology

[0002] In chemical, marine, and mining industries, control cables are exposed to complex environments such as acids, alkalis, salt spray, humidity, and mechanical vibration for extended periods. Traditional control cables typically use galvanized steel wire armor for mechanical protection, and fill the armor gaps with asphalt or ordinary grease to delay corrosion. However, existing technology has the following drawbacks:

[0003] 1. Armor crevice corrosion is difficult to prevent in the long term: The filled grease is statically stored and will gradually dry and run off as service time increases, causing the steel wire to be directly exposed to the corrosive medium, and crevice corrosion will develop rapidly. Even with double-layer armor and lubricating felt between the layers, only limited passive lubrication can be provided, and long-term active protection cannot be achieved.

[0004] 2. Lead sheaths are prone to fatigue cracking: Although lead sheaths have excellent chemical inertness and sealing properties, they have low strength and high creep, making them prone to fatigue cracks when cables are repeatedly bent. There is a lack of effective stress-relief structures in current technology.

[0005] 3. Damage to the outer sheath cannot be repaired: The outer sheath is easily scratched during installation or use, and the damage becomes a channel for corrosive media to enter. Traditional outer sheaths do not have self-repairing capabilities.

[0006] 4. Undetectable internal condition: Latent damage such as creep and armor corrosion of the lead sheath inside the cable cannot be monitored in real time. Maintenance personnel can only replace it periodically, which poses a risk of sudden failure.

[0007] Therefore, there is an urgent need for a new type of control cable that can achieve long-term active protection of armor gaps, fatigue resistance of lead sheath, and repairability and status awareness of outer sheath. Summary of the Invention

[0008] To address the shortcomings of the prior art, this invention provides a self-pumping lubricating corrosion-resistant control cable and its manufacturing and control methods, which prevent corrosion failure and fatigue cracking of the lead sheath caused by static storage of the lubricating medium, and can repair the armor gaps of the damaged outer sheath.

[0009] The technical solution adopted in this invention is:

[0010] A corrosion-resistant control cable with armored gap self-pumping lubrication, comprising, from the inside out, a cable core, each cable core being formed by twisting together at least two cable cores, each cable core including a tinned copper conductor, an insulation layer covering the tinned copper conductor, and a composite shielding layer covering the insulation layer; a first inner sheath extruded over the cable core; a corrugated metal buffer sleeve covering the first inner sheath; a lead alloy sheath covering the corrugated metal buffer sleeve; a second inner sheath extruded over the lead alloy sheath; a double-layer armor layer wound around the second inner sheath, the double-layer armor layer including an inner armor layer and an outer armor layer, with an annular gap between the inner and outer armor layers; a lubricating medium layer filling the annular gap, and a fluid pumping structure in contact with the lubricating medium layer being provided within the annular gap.

[0011] Preferably, the fluid pumping structure includes a spiral groove disposed on the outer surface of the inner armor and / or the inner surface of the outer armor, the spiral groove extending continuously along the cable axial direction.

[0012] Preferably, the spiral groove has a depth of 0.1-0.3 mm, a width of 0.2-0.5 mm, and a pitch ratio of 0.8-1.2 to the winding pitch of the armor layer. The bottom of the spiral groove is also provided with micro-horizontal lines spaced apart along the groove length. The depth of the micro-horizontal lines is 0.05-0.1 mm, and the spacing is 0.3-0.8 mm.

[0013] Preferably, the fluid pumping structure includes: a capillary core layer disposed within the annular gap, the capillary core layer being in contact with the lubricating medium layer; and a grease reservoir disposed at one or both ends of the cable, the capillary core layer being in communication with the interior of the grease reservoir, the grease reservoir storing the lubricating medium.

[0014] Preferably, the capillary core layer is a metal fiber felt, a sintered metal powder layer, or a woven metal mesh, with a pore size of 10-50 μm and a porosity of 30%-50%; the capillary core layer has a gradient pore structure along the cable axis, with the porosity at the end near the grease reservoir being higher than that at the end away from the grease reservoir.

[0015] Preferably, the lubricating medium layer contains dispersed thermally expandable microcapsules, the wall material of which is a thermoplastic polymer, and the microcapsules are encapsulated with a low-boiling-point propellant.

[0016] Preferably, it further includes a composite outer sheath disposed outside the double-layer armor layer. The composite outer sheath includes an inner elastomer and an outer hot-melt repair layer. The inner elastomer is a closed-cell foam elastomer with a porosity of 15%-30%, and the outer hot-melt repair layer is a thermoplastic polyolefin. The inner wall of the inner elastomer is provided with multiple axially extending guide grooves.

[0017] Preferably, it further includes a distributed optical fiber sensing unit embedded between the second inner sheath and the inner armor layer. The distributed optical fiber sensing unit includes at least two optical fibers, one of which is a strain sensing fiber, which is closely attached to the outer surface of the second inner sheath and arranged in a sinusoidal waveform along the cable axis; the other is a temperature sensing fiber, which is spirally wound around the outside of the strain sensing fiber and is provided with an isolation pad between it and the strain sensing fiber.

[0018] A method for manufacturing an armored, gapped, self-pumping, lubricated, corrosion-resistant control cable includes the following steps:

[0019] Step S1: Cable core preparation, in which an insulation layer and a composite shielding layer are sequentially wrapped around the outside of a tinned copper conductor to form a cable core, and at least two cable cores are twisted together to form a cable core;

[0020] Step S2: Inner sheath extrusion, forming the first inner sheath by extruding the cable core.

[0021] Step S3: Buffer sleeve covering, the corrugated metal strip is longitudinally wrapped around the outside of the first inner sheath to form a corrugated metal buffer sleeve, and a flexible heat-conducting medium is filled in the first radial gap between the buffer sleeve and the first inner sheath.

[0022] Step S4: Lead sheathing: A lead alloy sheath is wrapped around the corrugated metal buffer sleeve, and a flexible heat-conducting medium is filled in the second radial gap between the sheath and the corrugated metal buffer sleeve.

[0023] Step S5: Extrusion of the second inner sheath, forming the second inner sheath by extrusion on the outside of the lead alloy sheath;

[0024] Step S6: Fiber embedding, a distributed fiber optic sensing unit is arranged on the outer surface of the second inner sheath;

[0025] Step S7: Armor winding. The inner armor and outer armor are wound around the outside of the second inner sheath in sequence to form a double armor layer with an annular gap.

[0026] Step S8: Pumping structure forming, a fluid pumping structure is set in the annular gap;

[0027] Step S9: Lubricating medium filling, filling the annular gap with lubricating medium to form a lubricating medium layer;

[0028] Step S10: Outer sheath forming, forming a self-healing composite outer sheath outside the double-layer armor layer.

[0029] A control method for an armored, gap-sealed, self-pumping, lubricating, corrosion-resistant control cable includes:

[0030] Self-pumping lubrication control: When the cable is bent and deformed, the fluid pumping structure responds to the bending deformation by generating pumping pressure, driving the lubricating medium in the lubricating medium layer to flow axially along the cable, forming dynamic circulating lubrication in the armor gaps;

[0031] Thermal expansion microcapsules assist in sealing. When the local temperature of the cable rises, the thermal expansion microcapsules dispersed in the lubricating medium layer expand due to heat, which increases the volume and viscosity of the lubricating medium, automatically fills the armor gaps and enhances the seal. At the same time, they generate extrusion pressure towards both ends of the cable to assist the flow of the lubricating medium.

[0032] Self-healing control: When the outer heat-melting repair layer of the self-healing composite outer sheath is scratched, external heating is applied to melt the outer heat-melting repair layer. The melt flows into the scratch along the guide groove on the inner wall of the inner elastic body and solidifies and closes after cooling.

[0033] Condition monitoring uses strain sensing fibers and temperature sensing fibers in the distributed optical fiber sensing unit to acquire strain and temperature distribution along the cable in real time, thereby monitoring and locating the creep state of the lead alloy sheath and the damage location of the outer thermoplastic repair layer.

[0034] The advantages of this invention over the prior art are:

[0035] This invention relates to a self-pumping lubricating corrosion-resistant control cable with armored gaps, as well as its manufacturing and control methods. The armored gaps provide long-term active corrosion protection. Through a fluid pumping structure, the cable's own mechanical movement and capillary force are used as driving forces to ensure that the lubricating medium continuously circulates in the armored gaps, avoiding the problem of drying and failure of traditional static lubricating media.

[0036] The fatigue resistance of the lead sheath is significantly improved. The elastic deformation capacity of the corrugated metal buffer sleeve reduces the peak bending stress. Combined with radial gaps and flexible heat-conducting media, this extends the bending fatigue life of the lead sheath. The outer sheath allows for on-site thermal repair of the drainage channels and heat-fusion layer of the double-layer composite outer sheath. Scratches ≤0.5mm in depth can be repaired using a portable hot air gun, achieving a repair efficiency of ≥80% and reducing maintenance costs. Cable health status can be monitored online. Distributed fiber optic sensing units enable separate measurement of strain and temperature, accurately locating outer sheath damage and monitoring lead sheath creep, providing data support for predictive maintenance. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the armored gap self-pumping lubrication type corrosion-resistant control cable of the present invention;

[0038] Figure 2 This is a schematic diagram of the inner armored steel wire structure of the armored gap self-pumping lubrication type corrosion-resistant control cable of the present invention.

[0039] Figure 3 This is a schematic diagram of the outer armor steel wire structure of the armored gap self-pumping lubrication type corrosion-resistant control cable of the present invention;

[0040] Figure 4 This is a schematic diagram of the distributed optical fiber sensing unit in the axial longitudinal section of the armored gap self-pumping lubrication corrosion-resistant control cable of the present invention.

[0041] Figure 5 This is a schematic diagram of the fluid pumping structure of the armored gap self-pumping lubricating corrosion-resistant control cable of the present invention;

[0042] Figure 6 for Figure 5 Enlarged view of part A;

[0043] Figure 7 This is a schematic diagram of the cross-sectional structure of the micro-cross lines along the length of the spiral groove.

[0044] Explanation of symbols for key components in the attached diagram:

[0045] 1. Conductor; 2. Insulating layer; 3. Composite shielding layer; 4. First inner sheath; 5. Corrugated metal buffer sleeve; 51a. First radial gap; 51b. Second radial gap; 52. Flexible thermally conductive medium; 6. Lead alloy sheath; 61. Spiral reinforcing rib; 7. Second inner sheath; 8. Double-layer armor layer; 81. Inner armor layer; 82. Outer armor layer; 83. Annular gap; 84. Spiral groove; 85. Micro-cross striations; 86. Capillary core layer; 9. Lubricating medium layer; 91. Thermal expansion microcapsule; 99. Axis; 10. Self-healing composite outer sheath; 101. Inner elastomer layer; 102. Outer thermoplastic repair layer; 103. Flow guide groove; 11. Distributed optical fiber sensing unit; 111. Strain sensing optical fiber; 112. Temperature sensing optical fiber; 113. Isolation gasket. Detailed Implementation

[0046] The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0047] Appendix Figure 1-7It is known that an armored gap self-pumping lubrication corrosion-resistant control cable includes, from the inside out, a cable core, which is formed by twisting at least two cable cores. Each cable core includes a tinned copper conductor 1, an insulation layer 2 covering the tinned copper conductor 1, and a composite shielding layer 3 covering the insulation layer 2; a first inner sheath 4 extruded outside the cable core; a corrugated metal buffer sleeve 5 covering the first inner sheath 4; a lead alloy sheath 6 covering the corrugated metal buffer sleeve 5; a second inner sheath 7 extruded outside the lead alloy sheath 6; a double-layer armor layer 8 wound around the second inner sheath 7, the double-layer armor layer 8 including an inner armor layer 81 and an outer armor layer 82, with an annular gap 83 between the inner armor layer 81 and the outer armor layer 82; a lubricating medium layer 9 filled in the annular gap 83, and a fluid pumping structure in contact with the lubricating medium layer 9 provided in the annular gap 83.

[0048] Preferably, the fluid pumping structure includes a spiral groove 84 disposed on the outer surface of the inner armor 81 and / or the inner surface of the outer armor 82, the spiral groove 84 extending continuously along the cable axial direction.

[0049] Preferably, the spiral groove 84 has a depth of 0.1-0.3 mm, a width of 0.2-0.5 mm, and a pitch ratio of 0.8-1.2 to the winding pitch of the armor layer. The bottom of the spiral groove 84 is further provided with micro-horizontal lines 85 spaced apart along the length of the groove. The depth of the micro-horizontal lines 85 is 0.05-0.1 mm, and the spacing is 0.3-0.8 mm.

[0050] Preferably, the fluid pumping structure includes: a capillary core layer 86 disposed within the annular gap 83, the capillary core layer 86 being in contact with the lubricating medium layer 9; and a grease reservoir disposed at one or both ends of the cable, the capillary core layer 86 being in communication with the interior of the grease reservoir, the grease reservoir storing the lubricating medium.

[0051] Preferably, the capillary core layer 86 is a metal fiber felt, a sintered metal powder layer, or a woven metal mesh, with a pore size of 10-50 μm and a porosity of 30%-50%; the capillary core layer 86 has a gradient pore structure in the axial direction of the cable, with the porosity at the end near the grease reservoir being higher than that at the end away from the grease reservoir.

[0052] Preferably, the lubricating medium layer 9 contains dispersed thermally expandable microcapsules 91, the wall material of the thermally expandable microcapsules 91 being a thermoplastic polymer, and the interior encapsulating a low-boiling-point propellant.

[0053] Preferably, it further includes a composite outer sheath 10 disposed outside the double-layer armor layer 8. The composite outer sheath 10 includes an inner elastomer 101 and an outer hot-melt repair layer 102. The inner elastomer 101 is a closed-cell foam elastomer with a porosity of 15%-30%, and the outer hot-melt repair layer 102 is a thermoplastic polyolefin. The inner wall of the inner elastomer 101 is provided with multiple axially extending guide grooves 103.

[0054] Preferably, it further includes a distributed optical fiber sensing unit 11 embedded between the second inner sheath 7 and the inner armor 81. The distributed optical fiber sensing unit 11 includes at least two optical fibers, one of which is a strain sensing fiber 111, which is closely attached to the outer surface of the second inner sheath 7 and arranged in a sinusoidal waveform along the cable axis; the other is a temperature sensing fiber 112, which is spirally wound around the outside of the strain sensing fiber 111, and an isolation pad 113 is provided between the two fibers.

[0055] A method for manufacturing an armored, gapped, self-pumping, lubricated, corrosion-resistant control cable includes the following steps:

[0056] Step S1: Cable core preparation. The tinned copper conductor 1 is sequentially covered with an insulation layer 2 and a composite shielding layer 3 to form a cable core, and at least two cable cores are twisted together to form a cable core.

[0057] Step S2: Inner sheath extrusion, forming the first inner sheath 4 by extruding the cable core outside;

[0058] Step S3: Buffer sleeve covering, the corrugated metal strip is longitudinally wrapped around the outside of the first inner sheath 4 to form a corrugated metal buffer sleeve 5, and a flexible thermally conductive medium 52 is filled in the first radial gap 51a between it and the first inner sheath 4.

[0059] Step S4: Lead sheathing: A lead alloy sheath 6 is wrapped around the corrugated metal buffer sleeve 5, and a flexible thermally conductive medium 52 is filled in the second radial gap 51b between the sheath 6 and the corrugated metal buffer sleeve 5.

[0060] Step S5: Extrusion of the second inner sheath, forming the second inner sheath 7 by extruding it on the outside of the lead alloy sheath 6;

[0061] Step S6: Fiber embedding, a distributed fiber optic sensing unit 11 is arranged on the outer surface of the second inner sheath 7.

[0062] Step S7: Armor winding. Inner armor 81 and outer armor 82 are wound around the outside of the second inner sheath 7 in sequence to form a double armor layer 8 with annular gap 83.

[0063] Step S8: Pumping structure forming, a fluid pumping structure is set in the annular gap 83;

[0064] Step S9: Lubricating medium filling, filling the annular gap 83 with lubricating medium to form a lubricating medium layer 9;

[0065] Step S10: Outer sheath forming, forming a self-healing composite outer sheath 10 outside the double-layer armor layer 8.

[0066] A control method for an armored, gap-sealed, self-pumping, lubricating, corrosion-resistant control cable includes:

[0067] Self-pumping lubrication control: When the cable is bent and deformed, the fluid pumping structure responds to the bending deformation by generating pumping pressure, driving the lubricating medium in the lubricating medium layer 9 to flow axially along the cable, forming dynamic circulating lubrication in the armor gap;

[0068] Thermal expansion microcapsules assist in sealing. When the local temperature of the cable rises, the thermal expansion microcapsules 91 dispersed in the lubricating medium layer 9 expand due to heat, which increases the volume and viscosity of the lubricating medium, automatically fills the armor gaps and enhances the seal. At the same time, they generate extrusion pressure towards both ends of the cable to assist the flow of the lubricating medium.

[0069] Self-healing control: When the outer heat-melting repair layer 102 of the self-healing composite outer sheath 10 is scratched, external heating is applied to melt the outer heat-melting repair layer 102. The melt flows into the scratch along the guide groove 103 on the inner wall of the inner elastomer 101 and solidifies and closes after cooling.

[0070] Condition monitoring involves acquiring the strain and temperature distribution along the cable in real time through the strain sensing fiber 111 and temperature sensing fiber 112 in the distributed optical fiber sensing unit 11, thereby monitoring and locating the creep state of the lead alloy sheath 6 and the damage location of the outer thermoplastic repair layer 102.

[0071] The working principle of the cable of this invention is as follows:

[0072] When the cable is subjected to bending, stretching, or vibration during laying or use, the inner and outer armor steel wires slip relative to each other, and the spiral grooves with opposite directions form a shear flow, driving the lubricating medium to flow directionally along the cable axis, achieving dynamic lubrication. The capillary core layer utilizes the capillary pressure difference generated by the gradient pores to continuously draw the lubricating medium from the grease reservoir into the armor gaps throughout the cable. When the cable is overloaded or the ambient temperature rises, the temperature in the middle region is higher, and the thermally expanding microcapsules preferentially expand, increasing the volume and viscosity of the lubricating medium layer, automatically filling the gaps and enhancing the seal; simultaneously, the expansion generates compressive force towards both ends, assisting the medium flow. If the outer sheath is scratched, a hot air gun is used to heat it to approximately 100°C, melting the outer thermoplastic material, which flows into the wound along the guide groove, and solidifies and closes after cooling. An external fiber optic demodulator acquires real-time strain, temperature distribution, and the location of damage to the outer sheath along the cable. The longitudinally wrapped corrugated metal strip has a wave height of 1-3 mm and a wavelength of 3-8 mm. A radial gap of 0.1-0.3 mm is provided between the strip and both the first inner sheath and the lead alloy sheath, and this gap is filled with a flexible, heat-conducting medium. This structure absorbs strain energy through corrugated deformation when the cable bends, reducing the peak stress of the lead sheath by more than 70%.

[0073] Cable end sealing reduces grease leakage through zoning, multi-level, and redundancy. Zone A uses potting compound as the core to isolate the grease from the conductor; Zone B employs a four-level seal using interference fit, sealant, O-rings, and a detection cavity to ensure foolproof sealing at the armor gap exit; Zone C uses a three-level seal using wedge rings, O-rings, and heat shrink tubing to resist external corrosion.

[0074] Area A is located between the conductor insulation layer and the second inner sheath, preventing grease from leaking to the core wire side. It is achieved through the extension of the inner sheath, encapsulation with sealant, and heat shrink tubing.

[0075] Zone B is located at the armor gap outlet, between the capillary core layer and the connector, to prevent grease from leaking outwards, through interference fit, sealant, O-ring and compression nut.

[0076] Zone C is located between the outer sheath and the connector housing, preventing external moisture and dust from entering through wedge rings, O-rings, compression nuts, and heat shrink tubing.

[0077] Before sealing and assembling, perform pretreatment of the cable ends in the following order:

[0078] 1. Peel off the outer sheath. Use a ring cutter to peel off the outer sheath to a predetermined length, exposing the armor layer. The peeling length is 50~80mm depending on the joint.

[0079] 2. Peel off the armor layers, peeling off the outer armor and inner armor in sequence to expose the second inner sheath. Leave about 10mm of steel wire at the end of the inner armor for subsequent fixing.

[0080] 3. Pre-treatment for sealing area A: In the annular gap between the second inner sheath and the conductor insulation layer, epoxy sealant is injected using a glue gun and allowed to cure. Then, a double-walled heat shrink tube is fitted on the outside and heated to shrink, forming a seal in area A. This step must be completed before the subsequent assembly of areas B and C.

[0081] 4. Capillary core layer end treatment: Peel off the exposed capillary core layer end, about 30~40mm in length. If the core layer material is flexible metal fiber felt, it needs to be twisted and oriented: Twist the core layer end to be parallel to the cable axis to form a gradual transition section, and cut it perpendicular to the cable axis with a sharp knife to obtain a straight end face that is perpendicular to the axis.

[0082] 5. Wrap the end of the armored steel wire: Wrap the 10mm section of the inner armored steel wire end with epoxy resin or solder to form a ring, eliminating gaps between the steel wires and making it fit with the inside of the joint housing.

[0083] Assembly process for sealing area B:

[0084] Level 1: Interference fit compression seal. The transition connector housing has a rectangular socket, slightly smaller than the capillary core end. During operation, the transition connector housing is placed over the cable, with the rectangular socket facing the core end. A thin layer of RTV silicone sealant is evenly applied to the width and thickness directions of the rectangular cross-section on the outer surface of the capillary core end. The core end is then aligned with the rectangular socket inlet, ensuring width and thickness are aligned. Using a pressing tool or manually applying axial force along the cable, the core end is inserted into the socket until the end face touches the bottom of the socket, compressing the core. The elastic deformation of the core material generates radial pressure, pressing it tightly against the socket wall; the sealant fills the gaps.

[0085] Second stage: Sealant curing and sealing. After the interference fit assembly is completed, the transition joint is placed at room temperature or heated to 50~60℃ to allow the sealant to fully cure, bonding the core layer to the socket wall as one unit.

[0086] The third stage: O-ring seal at the root of the armored steel wire. The structural components include a ring-shaped O-ring made of fluororubber, a clamping nut, and a tapered pressure ring. A matching O-ring is placed in the annular space between the armored steel wire sheath and the connector housing. Then, the inner conical surface of a tapered pressure ring is installed, contacting the O-ring, and the clamping nut is tightened. When the nut is tightened, the pressure ring moves axially, compressing the O-ring and causing it to expand radially, pressing it tightly against the steel wire sheath and the inner wall of the connector housing to form a seal.

[0087] Fourth stage: Overall compression and detection chamber. An annular detection chamber is set in the middle of the connector housing, communicating with area B. The outer wall of the detection chamber has radial threaded holes, normally sealed with a plug. After completing the above three-stage sealing, inject grease into area B through the grease reservoir using a grease gun, while simultaneously loosening the plug in the detection chamber. Once grease flows out of the detection port, indicating that internal air has been purged, immediately tighten the plug. The detection chamber not only serves as a leak observation port but also acts as a buffer chamber. When there is a slight leakage from the first and second stage seals, the leaked grease will accumulate in the detection chamber and will not overflow.

[0088] Area C is sealed to prevent external moisture, salt spray, and dust from entering the joint.

[0089] First stage: Wedge ring + O-ring combination seal. The structural components include a wedge rubber ring, an O-ring made of nitrile rubber, and a compression nut. First, the O-ring is placed on the cable's outer sheath and pushed to the cable inlet of the connector housing. Then, the wedge ring is placed on the cable's outer sheath, with its outer conical surface mating with the inner conical surface of the connector housing. Finally, the compression nut is tightened. The nut pushes the compression ring, compressing the wedge ring and causing it to contract radially, tightly gripping the cable's outer sheath. Simultaneously, the compression ring compresses the O-ring, causing it to compress axially and expand radially, sealing the gap between the outer sheath and the housing. The wedge ring and O-ring work together to form a bidirectional seal.

[0090] Second stage: Heat shrink tubing for auxiliary sealing. A section of double-walled heat shrink tubing with hot melt adhesive is then fitted over the clamping nut, covering the joint between the connector housing and the cable sheath. Heated with a heat gun, the hot melt adhesive melts and fills all gaps, causing the tubing to shrink and tightly wrap the connector and cable. The heat shrink tubing provides additional environmental isolation, preventing moisture penetration along the threaded seams, while also mechanically protecting the clamping nut from loosening.

[0091] The O-ring in the third stage of zone B is replaceable. During maintenance, remove the clamping nut, take out the old O-ring, replace it with the new one, and tighten it again. It is not necessary to disassemble the first and second stage seals when replacing it.

[0092] The wedge ring and O-ring sealing in zone C are also replaceable. The heat shrink tubing is disposable and needs to be reheated and shrunk after replacement.

[0093] After completing the end sealing, especially the insertion of the capillary core layer in zone B into the rectangular socket, the cable still needs to have its internal conductor cores led out and electrically connected to external equipment such as control cabinets, instruments, and junction boxes. The following details the structural layout, conductor lead-out method, electrical connection method, and overall assembly process.

[0094] The cable termination is connected to a terminal block or equipment interface via a transition joint. The overall structure from the inside out consists of: the cable body, including conductor, insulation, sheath, armor, and capillary core layer; the transition joint seals the armor gaps, connects the capillary core layer, and introduces lubricant; the exposed insulated conductor of the connection section; and the electrical termination terminal block, plug, or direct connection to the equipment.

[0095] The transition connector housing has a hollow structure with a through circular channel in the center. This channel is spatially isolated from the rectangular socket. The rectangular socket is located on the outer periphery of the housing, corresponding to the armor gap, while the central channel corresponds to the core wire area of ​​the cable.

[0096] The transition joint housing is equipped with a flange or threads, allowing it to be directly installed on the control cabinet's cable entry board. In this case, one part of the joint housing is located outside the cabinet for connecting cables, while the other part is located inside the cabinet for leading out the core wires. The core wires of the part inside the cabinet are directly connected to the terminals inside the cabinet.

[0097] The grease reservoir is installed on the side or below the tail of the transition joint housing and is connected to Zone B through a transition capillary joint. The grease reservoir is located on the radial side of the transition joint housing and is offset from the central channel.

[0098] The cable end is connected to external equipment via a central channel of a transition joint, which is spatially isolated from rectangular sockets used for sealing and lubrication. The insulated core wire emerges from the central channel, is stripped and crimped using conventional methods, and then connected to the terminals of the external equipment.

[0099] The capillary core layer 86 is a porous medium layer set in the annular gap 83 between the double armor layers. It is made of metal fiber felt, sintered metal powder layer or woven metal mesh, and has micron-level interconnected pores with an equivalent pore size of 10-50μm and a porosity of 30%-50%. It utilizes capillary force to achieve long-distance, non-powered, continuous suction and uniform distribution of the lubricating medium.

[0100] When the cable is stationary and without bending or vibration, the shearing pumping mechanism of the spiral groove does not operate. The capillary core layer utilizes the capillary pressure generated by the micropores, which can reach tens of kilopascals, to continuously draw lubricating grease from the grease reservoir and slowly seep out along the armor gaps throughout the cable, ensuring that the steel wire surface always maintains an extremely thin lubricating film. This function ensures that the armor gaps are effectively protected during long-term static storage or intermittent operation of the cable.

[0101] The shear pumping of the spiral grooves generates additional driving pressure when the cable bends, pushing the lubricating medium a greater distance. The capillary core layer acts as an intermediate carrier, receiving and storing the grease drawn from the grease reservoir while evenly distributing the grease to the inlets of each spiral groove.

[0102] In applications where cables frequently bend, the pumping speed of the spiral groove pump may exceed the direct supply speed of the grease reservoir, especially at the far end of long-distance cables. The high porosity (30%-50%) of the capillary core layer makes it itself a distributed grease reservoir, capable of temporarily storing a certain amount of grease. When pumping demand exceeds the instantaneous supply, the core layer releases the stored grease; when pumping slows down, the core layer is replenished from the grease reservoir.

[0103] The grease in the grease reservoir comes into contact with the proximal large-pore core layer. Due to the large pore size and low capillary pressure at the proximal end, the grease is easily drawn into the core layer. Once the core layer is partially wetted, a capillary pressure difference is generated along the pore size gradient direction, with higher pressure at the distal end and lower pressure at the proximal end, driving the grease to automatically migrate towards the distal end.

[0104] Micro-grooves refer to an array of micro-grooves or protrusions machined perpendicular to the length of the spiral groove at the bottom of the groove. The cross-sectional shape is asymmetrical, serrated, or trapezoidal, with clearly defined gentle and steep slopes. The depth is typically 0.05 to 0.1 mm, about one-quarter to one-half of the spiral groove depth; the spacing is 0.3 to 0.8 mm, which is the distance between the centers of adjacent grooves; the slope angle of the gentle slope is 5 to 30 degrees, which is a gentle slope that allows the fluid to climb smoothly; the slope angle of the steep slope is 60 to 90 degrees, which is a steep slope used to generate high resistance; the width of the grooves is the same as or slightly narrower than the width of the spiral groove to ensure that the entire bottom of the groove is covered.

[0105] For each micro-ripple, a gentle slope is a gently sloping surface with its orientation set to the direction of the desired flow source; a steep slope is a steeply sloping surface with its orientation set to the direction of the desired flow destination.

[0106] The grease reservoir is installed at end A of the cable, with the lubricating medium expected to be transported from end A to the far end B. The gentle slope faces end A (the grease reservoir end), and the steep slope faces end B (the far end). The gentle slope is located on the side closer to the grease reservoir, and the steep slope is located on the side closer to the far end.

[0107] Viewed axially along the groove, each micro-striate is serrated, with a gentle slope on the left and a steep slope on the right. The desired flow direction is from left to right. In the forward flow from end A to end B, the fluid first contacts the gentle slope and rises smoothly along it with low resistance; in the reverse flow from end B to end A, the fluid first contacts the steep slope, impacting a nearly vertical surface with extremely high resistance.

[0108] During forward flow, particles roll or slide along gentle slopes. Due to the gentle slope, the normal force on the particles is small, and the inertial force allows the particles to pass over the top of the transverse lines without getting stuck. Smaller particles, such as nanoparticles, are suspended in the fluid and flow around the transverse lines without causing blockage. Therefore, the particles are transported forward along with the lubricating medium without clogging the micro-transverse lines.

[0109] In reverse flow, particles are carried by the fluid toward the steep slope, and upon impact, may become embedded in the angle between the slope surface and the bottom of the channel. For elastic particles, such as thermally expanded microcapsules, they are mechanically locked after deformation upon impact. Multiple particles accumulate on the windward side of the steep slope, blocking the transverse openings. The stuck particles reduce the flow area, increase the local velocity, causing more particles to be carried and stuck, gradually enhancing the resistance to backflow. Therefore, reverse flow is not only subject to high fluid dynamic resistance, but is also further physically blocked by particle sticking, forming a double protection.

[0110] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the structure of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. An armored, gapped, self-pumping, lubricating, corrosion-resistant control cable, comprising, from the inside out, a cable core, wherein the cable core is formed by twisting together at least two cable cores, each cable core comprising a tinned copper conductor (1), an insulation layer (2) covering the tinned copper conductor (1), and a composite shielding layer (3) covering the insulation layer (2); a first inner sheath (4) extruded over the cable core; and a corrugated metal buffer sleeve (5) covering the first inner sheath (4). A lead alloy sheath (6) covering the corrugated metal buffer sleeve (5); a second inner sheath (7) extruded onto the lead alloy sheath (6); a double-layer armor layer (8) wound around the second inner sheath (7), the double-layer armor layer (8) comprising an inner armor layer (81) and an outer armor layer (82), wherein an annular gap (83) is provided between the inner armor layer (81) and the outer armor layer (82); a lubricating medium layer (9) filling the annular gap (83), characterized in that, A fluid pumping structure that contacts the lubricating medium layer (9) is provided inside the annular gap (83).

2. The armored, gap-sealed, self-pumping, lubricating, corrosion-resistant control cable according to claim 1, characterized in that, The fluid pumping structure includes a spiral groove (84) disposed on the outer surface of the inner armor (81) and / or the inner surface of the outer armor (82), the spiral groove (84) extending continuously along the cable axis.

3. The armored, gap-sealed, self-pumping, lubricating, corrosion-resistant control cable according to claim 2, characterized in that, The bottom of the spiral groove (84) is also provided with micro-horizontal lines (85) distributed at intervals along the length of the groove.

4. The armored, gap-sealed, self-pumping, lubricating, corrosion-resistant control cable according to claim 3, characterized in that, The fluid pumping structure includes: a capillary core layer (86) disposed in the annular gap (83), the capillary core layer (86) being in contact with the lubricating medium layer (9); a grease reservoir is provided at one end of the cable, the capillary core layer (86) being connected to the interior of the grease reservoir, and the grease reservoir storing the lubricating medium.

5. The armored, gap-sealed, self-pumping, lubricating, corrosion-resistant control cable according to claim 4, characterized in that, The capillary core layer (86) is a metal fiber felt, a sintered metal powder layer or a woven metal mesh. The capillary core layer (86) has a gradient pore structure in the axial direction of the cable, and the porosity at the end near the grease reservoir is higher than that at the end away from the grease reservoir.

6. The armored, gap-sealed, self-pumping, lubricating, corrosion-resistant control cable according to claim 1, characterized in that, The lubricating medium layer (9) contains dispersed thermally expandable microcapsules (91), the wall material of which is a thermoplastic polymer and encapsulates a low-boiling-point propellant.

7. The armored, gap-sealed, self-pumping, lubricating, corrosion-resistant control cable according to claim 1, characterized in that, It also includes a composite outer sheath (10) disposed outside the double-layer armor layer (8), the composite outer sheath (10) comprising an inner elastomer (101) and an outer hot-melt repair layer (102), the inner elastomer (101) being a closed-cell foam elastomer and the outer hot-melt repair layer (102) being a thermoplastic polyolefin; the inner wall of the inner elastomer (101) is provided with multiple axially extending guide grooves (103).

8. The armored, gap-sealed, self-pumping, lubricating, corrosion-resistant control cable according to claim 1, characterized in that, It also includes a distributed optical fiber sensing unit (11) embedded between the second inner sheath (7) and the inner armor (81). The distributed optical fiber sensing unit (11) includes at least two optical fibers, one of which is a strain sensing fiber (111) that is close to the outer surface of the second inner sheath (7) and arranged in a sinusoidal waveform along the cable axis; the other is a temperature sensing fiber (112) that is spirally wound around the outside of the strain sensing fiber (111) and is provided with an isolation pad (113) between it and the strain sensing fiber (111).

9. A method for manufacturing an armored, gap-sealed, self-pumping, lubricated, corrosion-resistant control cable as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Step S1: Cable core preparation. The tin-plated copper conductor (1) is wrapped with an insulation layer (2) and a composite shielding layer (3) in sequence to form a cable core, and at least two cable cores are twisted together to form a cable core. Step S2: Inner sheath extrusion, the first inner sheath is formed by extruding on the outside of the cable core (4). Step S3: Buffer sleeve covering, the corrugated metal strip is longitudinally wrapped around the outside of the first inner sheath (4) to form a corrugated metal buffer sleeve (5), and a flexible thermally conductive medium (52) is filled in the first radial gap (51a) between it and the first inner sheath (4). Step S4: Lead sheathing: A lead alloy sheath (6) is wrapped around the corrugated metal buffer sleeve (5), and a flexible thermally conductive medium (52) is filled in the second radial gap (51b) between the sheath and the corrugated metal buffer sleeve (5). Step S5: Extrusion of the second inner sheath, forming the second inner sheath (7) by extrusion outside the lead alloy sheath (6); Step S6: Fiber embedding, a distributed fiber sensing unit (11) is arranged on the outer surface of the second inner sheath (7). Step S7: Armor winding. The inner armor (81) and outer armor (82) are wound around the outside of the second inner sheath (7) to form a double armor layer (8) with an annular gap (83). Step S8: Pumping structure forming, a fluid pumping structure is set in the annular gap (83); Step S9: Lubricating medium filling, lubricating medium is filled into the annular gap (83) to form a lubricating medium layer (9). Step S10: Outer sheath forming, forming a self-healing composite outer sheath (10) outside the double-layer armor layer (8).

10. A control method based on the armored gap self-pumping lubricating corrosion-resistant control cable according to any one of claims 1 to 8, characterized in that, include: Self-pumping lubrication control: When the cable is bent and deformed, the fluid pumping structure responds to the bending deformation and generates pumping pressure, driving the lubricating medium in the lubricating medium layer (9) to flow axially along the cable, forming dynamic circulating lubrication in the armor gap; Thermal expansion microcapsules assist in sealing. When the local temperature of the cable rises, the thermal expansion microcapsules (91) dispersed in the lubricating medium layer (9) expand due to heat, fill the armor gaps and enhance the seal, and at the same time generate extrusion pressure to both ends of the cable to assist the flow of the lubricating medium. Self-healing control: When the outer heat-melting repair layer (102) of the self-healing composite outer sheath (10) is scratched, external heating is applied to melt the outer heat-melting repair layer (102). The melt flows into the scratch along the guide groove (103) on the inner wall of the inner elastomer (101), and solidifies and closes after cooling. Condition monitoring is performed by acquiring the strain and temperature distribution along the cable in real time through the strain sensing fiber (111) and temperature sensing fiber (112) in the distributed optical fiber sensing unit (11), thereby monitoring and locating the creep state of the lead alloy sheath (6) and the damage location of the outer thermoplastic repair layer (102).

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