An adaptive nitrogen balance cylinder and method of manufacturing the same

Abstract

This invention relates to the field of automated equipment technology, and in particular discloses an adaptive nitrogen balancing cylinder and its manufacturing method. The adaptive nitrogen balancing cylinder includes a hollow cylinder, an end cap, and a reciprocating piston. The piston includes a piston rod and a piston portion, with the piston portion extending into the cylinder to form a high-pressure gas chamber and isolate it from the outside. The piston rod extends to the outside of the cylinder. The end cap has an inflation portion that communicates with the high-pressure gas chamber. A middle sleeve assembly is located between the other end of the cylinder and the piston rod, with the piston rod passing through the middle sleeve assembly. A lubricating medium is provided between the piston rod, the cylinder, and the middle sleeve assembly. The middle sleeve assembly includes a middle sleeve body, a wear-resistant sleeve, and a sealing structure. The middle sleeve body is used to stop the piston portion from falling out. The wear-resistant sleeve is located between the piston, the middle sleeve assembly, and the inner wall of the cylinder. The sealing structure is used to provide a seal and prevent the lubricating medium from being scraped away. When the piston rod moves, the volume of the high-pressure gas chamber is compressed or expanded, and a reverse balancing force is generated to counteract the external load due to the compressibility of the gas.

Description

Technical Field

[0001] This invention relates to the field of automated equipment technology, and in particular discloses an adaptive nitrogen balance cylinder and its manufacturing method. Background Technology

[0002] In existing technologies, automated equipment such as industrial robots and machine tool spindle units typically require counterweight balancing devices when performing heavy-load, high-speed reciprocating operations. Traditional mechanical spring counterweights, while simple in structure, are bulky and their elasticity diminishes with repeated use, making them unable to continuously provide stable support under several tons of high pressure. Meanwhile, balance cylinders driven by external pneumatic or hydraulic lines generally suffer from system complexity, oil leaks, high-pressure gas leaks, and response lag, severely limiting the processing accuracy and dynamic response speed of the equipment under high-speed, heavy-load conditions. Furthermore, the overall lifespan of such devices is insufficient to meet the demands of continuous industrial production. Summary of the Invention

[0003] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this invention is to provide an adaptive nitrogen balance cylinder and its manufacturing method.

[0004] To achieve the above objectives, the present invention provides an adaptive nitrogen balance cylinder, comprising a hollow cylinder barrel, an end cap disposed at one end of the cylinder barrel, and a piston reciprocatingly disposed within the cylinder barrel; the piston comprises a piston rod and a piston portion, the piston portion extending into the cylinder barrel to form a high-pressure gas chamber within the cylinder barrel and to isolate the high-pressure gas chamber from the external environment, the piston rod extending to the outside of the cylinder barrel; the end cap is provided with an inflation portion communicating with the high-pressure gas chamber, through which high-pressure nitrogen is injected into the high-pressure gas chamber; It also includes an annular intermediate sleeve assembly disposed between the other end of the cylinder and the piston rod; the free end of the piston rod extends through the intermediate sleeve assembly to the outside of the cylinder; lubricating medium is provided between the piston rod and the cylinder, and between the piston rod and the intermediate sleeve assembly; the intermediate sleeve assembly includes an intermediate sleeve body, a wear-resistant sleeve, and a sealing structure. The intermediate sleeve body is used to stop and abut against the piston part to limit the piston part from exiting the cylinder. The wear-resistant sleeve is disposed between the piston part and the intermediate sleeve assembly and between the piston part and the inner wall of the cylinder. The sealing structure is used to provide a seal when the piston part reciprocates and to block and scrape off the lubricating medium on the surface of the piston part, the cylinder, and the intermediate sleeve assembly; when the piston rod moves relative to the cylinder under external load, the gas volume in the high-pressure gas chamber undergoes compression or expansion changes, and the compressibility of the high-pressure gas adaptively generates a reverse balancing force to counteract the current external load.

[0005] Furthermore, a stepped interlocking structure is provided between the end cap and the cylinder; a trapezoidal groove is formed between the outer peripheral wall of the end cap and the end of the cylinder; two circumferential welded structures are provided between the end cap and the cylinder. The first circumferential welded structure is located at the mating gap of the stepped interlocking structure to make the end cap and the end of the cylinder melt-sealed connection; the second circumferential welded structure is located in the trapezoidal groove and fills the trapezoidal groove to strengthen the bonding strength between the end cap and the cylinder.

[0006] Furthermore, the cylinder barrel is made of Q345 material, and the inner surface of the cylinder barrel is provided with a mirror layer formed by precision machining and grinding and polishing, and the surface roughness Ra of the mirror layer is 0.05-0.1.

[0007] Preferably, the surface roughness Ra of the mirror layer is 0.08.

[0008] Furthermore, the piston component is formed by integral forging. The piston component surface is provided with a tempering and hardening layer, a rough grinding layer, an ion nitriding layer and a fine grinding and polishing layer from the inside to the outside. The surface roughness Ra of the outer circle of the fine grinding and polishing layer is 0.02-0.05.

[0009] Preferably, the surface roughness Ra of the outer circle of the finely ground and polished layer is 0.03.

[0010] Furthermore, the wear-resistant sleeve is arranged in a ring shape, and at least two wear-resistant sleeves are provided; the outer wall of the piston part is provided with a first mounting groove, and the inner wall of the middle sleeve body is provided with a second mounting groove; the first wear-resistant sleeve is installed in the first mounting groove, and the outer surface of the first wear-resistant sleeve abuts against the inner wall of the cylinder; the second wear-resistant sleeve is installed in the second mounting groove, and the outer wall of the second wear-resistant sleeve abuts against the outer surface of the piston rod.

[0011] Preferably, the wear-resistant sleeve is a graphite copper sleeve.

[0012] Furthermore, it also includes an anti-detachment limiting structure; the anti-detachment limiting structure includes a first groove formed along the circumferential direction on the inner wall of the cylinder, a second groove arranged along the circumferential direction on the outer periphery of the middle sleeve body, and a limiting spring located between the first groove and the second groove; the first groove has a radially inwardly tapered first inclined inner wall and an arc-shaped first groove, and the second groove has a radially inwardly tapered second inclined inner wall and an arc-shaped second groove; the limiting spring is arranged in a ring shape and is embedded in the first groove and the second groove; the other end of the middle sleeve assembly and the cylinder are engaged and hooked in the opposite direction by the anti-detachment limiting structure in the assembled state.

[0013] Furthermore, it also includes an outer dust cover and an inner dust cover; the outer dust cover is located between the outer wall of the middle sleeve body and the inner wall of the cylinder, and the inner dust cover is located between the inner wall of the middle sleeve body and the outer surface of the piston rod.

[0014] Furthermore, the inner wall of the middle sleeve body is also provided with annular oil grooves, which are used to fill lubricating medium.

[0015] Furthermore, the lubricating medium is a grease, preferably a lithium-based grease or a lithium molybdenum disulfide grease.

[0016] Preferably, the lubricating medium is injected and distributed in the following manner: Oil injection hole or grease nipple: The end cap, the middle sleeve body, or the piston rod connector are all provided with an oil injection hole that connects to the internal friction surface. During assembly or maintenance, grease is forcibly injected through the oil injection hole using a grease gun.

[0017] Oil reservoir: The oil reservoir on the inner wall of the middle sleeve body is connected to the oil injection hole. When grease is injected from the oil injection hole, it first fills the oil reservoir, forming a "grease reservoir".

[0018] Distribution path: During the reciprocating motion of the piston rod, the grease in the oil reservoir is carried out and evenly applied between the graphite copper sleeve and the outer wall of the piston rod, as well as between the piston and the inner wall of the cylinder. Utilizing the self-lubricating properties of the graphite copper sleeve itself, combined with the externally injected grease, a dual lubrication system can be formed.

[0019] Furthermore, there are two second mounting slots, which are arranged at intervals along the axial direction of the middle sleeve body. There are three wear-resistant sleeves, with the first wear-resistant sleeve installed in the first mounting slot, the second wear-resistant sleeve installed in the first second mounting slot, and the third wear-resistant sleeve installed in the second second mounting slot. The oil groove is located between the two second mounting slots.

[0020] Furthermore, the sealing structure includes a first sealing groove formed on the outer wall of the middle sleeve body in the circumferential direction, a first sealing ring disposed in the first sealing groove, a second sealing groove formed on the inner wall of the middle sleeve body in the circumferential direction, and a second sealing ring disposed in the second sealing groove; the opening direction of the first sealing groove is opposite to the opening direction of the second sealing groove; the first sealing ring is an O-ring, and the second sealing ring is a Y-ring.

[0021] Furthermore, the sealing structure also includes a third sealing groove formed in the inner wall of the middle sleeve body along the circumferential direction, a third sealing ring disposed in the third sealing groove, and a fourth sealing ring disposed outside the third sealing ring; the cross-section of the third sealing ring is circular, and the cross-section of the fourth sealing ring is square.

[0022] Furthermore, the piston section is provided with multiple air passages that connect to the high-pressure air chamber, and the multiple air passages are arranged in a ring array around the central axis of the piston section.

[0023] Preferably, the inflation part includes a generally T-shaped first hole and a straight second hole. The first hole is arranged along the radial direction of the end cap, and the second hole is arranged along the axial direction of the end cap. The second hole is located at the central axis of the end cap. The first hole and the second hole are intersecting and communicating. The second hole is connected to the high-pressure air chamber. The first hole is provided with a valve core and a plug sealing screw.

[0024] The present invention provides a method for manufacturing an adaptive nitrogen balance cylinder, comprising the following steps: S1, Material preparation: manufacture end caps, cylinders, piston parts and intermediate sleeve assemblies, and provide lubricating medium and high-pressure gas charging equipment. The cylinder is hollow, and the inner hole of the cylinder is precision machined and then ground and polished. The end cap is provided with a charging part connected to the hollow part of the cylinder. The piston parts are heat treated, then precision machined, then rough ground, then ion nitrided, and then finely ground and polished. The intermediate sleeve assembly includes the intermediate sleeve body, wear-resistant sleeve and sealing structure. S2, Pre-assembly: The end cap is sealed and fixedly connected to one end of the cylinder, so that one end of the cylinder is sealed and the other end forms a chamber for installing the intermediate sleeve assembly and piston parts; S3, Middle Sleeve Assembly: Install the wear-resistant sleeve and sealing structure at the corresponding positions on the middle sleeve body to form a ring-shaped middle sleeve assembly; S4, Overall Assembly: Insert one end of the piston component with the piston part into the cylinder, and put the middle sleeve assembly from step S3 onto the piston rod and install it at the other end opening of the cylinder to seal the other end opening of the cylinder, so that a high-pressure air chamber connected to the inflation part is formed inside the cylinder; let the other end of the piston rod extend through the middle sleeve assembly to the outside of the cylinder, and form a sealed sliding fit between the piston rod and the cylinder through the sealing structure and lubrication medium; S5, Filling with high-pressure gas: High-pressure gas is injected into the high-pressure gas chamber from the inflation part of the end cap using a high-pressure gas inflation device; when the piston rod moves relative to the cylinder under the action of an external load, the gas volume in the high-pressure gas chamber changes due to compression or expansion. Relying on the compressibility of the high-pressure gas, an adaptive reverse balancing force is generated to counteract the current external load, so as to obtain the adaptive nitrogen balance cylinder.

[0025] Furthermore, in step S1, the inner bore of the cylinder is machined using a precision turning followed by grinding and polishing process, so that the surface roughness Ra of the inner bore of the cylinder after grinding and polishing reaches 0.08; the piston rod is processed by quenching and tempering, precision turning, rough grinding, ion nitriding, and fine grinding and polishing processes, so that the surface roughness Ra of the outer circle of the piston rod reaches 0.03.

[0026] Furthermore, a stepped interlocking structure is pre-set at the connection between the end cap and the cylinder for positioning and fitting, and a trapezoidal groove is formed between the outer peripheral wall of the end cap and the end of the cylinder; subsequently, two welding processes are performed: The first welding step is a full penetration weld at the mating gap of the stepped interlocking structure, so that the end cap and the cylinder end are fused and sealed together. The second welding fills the trapezoidal groove, which is used to reinforce the end cap and cylinder and improve their tensile strength.

[0027] Further, in step S3, the installation of the wear-resistant sleeve includes installing at least two wear-resistant sleeves into the first mounting groove on the outer wall of the piston part and the second mounting groove on the inner wall of the middle sleeve body, so that the outer surface of the first wear-resistant sleeve is used to abut against the inner wall of the cylinder, and the outer wall of the second wear-resistant sleeve is used to abut against the outer surface of the piston rod.

[0028] By using a wear-resistant sleeve for bidirectional isolation support between the piston and the intermediate sleeve assembly, the nitrogen balance cylinder's resistance to off-center loading and its wear resistance are improved during high-frequency reciprocating motion.

[0029] Furthermore, in step S4, when the middle sleeve assembly is installed at the other end opening of the cylinder, axial locking is achieved through the anti-disengagement limiting structure: first, the annular limiting snap ring is radially contracted and placed in the first groove on the inner wall of the cylinder, and then the middle sleeve body is pushed into the cylinder opening until the second groove on the outer periphery of the middle sleeve body is aligned with the first groove. Under its elastic reset action, the snap ring expands outward and is simultaneously locked between the first groove and the second groove.

[0030] By utilizing the radially inward-sloping inner walls and arc-shaped grooves of the first and second grooves respectively, the intermediate sleeve assembly and the cylinder barrel form a reverse meshing connection in the assembled state, effectively preventing the intermediate sleeve assembly from detaching from the cylinder barrel due to the thrust of the high-pressure air chamber.

[0031] Furthermore, in step S3, the installation of the sealing structure also includes: installing a first sealing ring (preferably an O-ring) in the first sealing groove on the outer wall of the middle sleeve body, and installing a second sealing ring (preferably a Y-ring) in the second sealing groove on the inner wall of the middle sleeve body, wherein the opening direction of the Y-ring is set towards the high-pressure gas chamber side to achieve a one-way gas sealing function; Meanwhile, the outer dust cover and the inner dust cover are respectively positioned between the outer wall of the middle sleeve body and the inner wall of the cylinder, and between the inner wall of the middle sleeve body and the outer surface of the piston rod, effectively preventing the intrusion of external dust and impurities.

[0032] Furthermore, the lubricating medium provided in step S1 is preferably lithium-based grease, and an oil injection hole communicating with the internal friction surface is pre-opened on the end cap, the middle sleeve body or the piston rod connector, and an annular oil groove communicating with the oil injection hole is opened on the inner wall of the middle sleeve body. In step S3, lithium-based grease is injected through the injection hole and fills the oil groove so that it is carried out by the piston rod during the reciprocating motion and evenly coated between the graphite copper sleeve and the piston rod. Combined with the self-lubricating properties of the graphite copper sleeve, a dual lubrication system is formed.

[0033] Furthermore, in step S3, the sealing structure also includes a third sealing ring with a circular cross-section and a fourth sealing ring with a square cross-section, which are jointly disposed in the third sealing groove on the inner wall of the middle sleeve body. The third sealing ring and the fourth sealing ring are arranged radially in sequence in the third sealing groove and abut against each other and squeeze together.

[0034] The square cross-section of the fourth sealing ring effectively scrapes away the grease adhering to the piston rod surface during reciprocating movement, preventing it from seeping into the high-pressure air chamber and achieving good secondary sealing and grease scraping functions. The beneficial effects of this invention are as follows: This invention effectively solves the pain points of traditional balancing devices, which rely on external pipelines, are prone to leakage, and have short lifespans. Utilizing the adaptive balancing characteristics of the compressibility of high-pressure nitrogen, it eliminates the need for an external power source, significantly reducing energy consumption and space occupation, and also significantly improving the working response speed and load motion accuracy of robots and machine tools. Simultaneously, through a stepped interlocking double-welded structure, a beveled anti-disengagement spring limiting design, and a multi-stage anti-wear and oil-scraping sealing system, it achieves extremely strong structural safety and anti-eccentric load capacity under high-pressure conditions of several tons, greatly reducing frictional wear between the piston rod and the seals, preventing lubricant leakage and high-pressure gas leakage, thus significantly extending the service life of the balancing cylinder. Attached Figure Description

[0035] Figure 1 This is a three-dimensional structural schematic diagram of the adaptive nitrogen balance cylinder of the present invention; Figure 2 This is a cross-sectional view of the adaptive nitrogen balance cylinder of the present invention; Figure 3 This is an exploded structural diagram of the adaptive nitrogen balance cylinder of the present invention; Figure 4 This is an exploded structural diagram of the middle sleeve component of the present invention; Figure 5 This is a three-dimensional structural diagram of the adaptive nitrogen balance cylinder of the present invention after cross-section; Figure 6 for Figure 5 A magnified structural diagram of part A in the middle; Figure 7 for Figure 5 A magnified structural diagram of part B in the middle section; Figure 8 This is a three-dimensional structural diagram of the middle sleeve component of the present invention after being cut apart; Figure 9 This diagram illustrates the steps of manufacturing the adaptive nitrogen balance cylinder of the present invention.

[0036] The reference numerals in the figures include: 1. Cylinder; 2. End cap; 3. Piston assembly; 4. Intermediate sleeve assembly; 5. Stepped interlocking structure; 10. High-pressure air chamber; 21. Inflation section; 211. First bore; 212. Second bore; 213. Valve core; 214. Plug sealing screw; 31. Piston rod; 32. Piston section; 321. First mounting groove; 322. Air passage; 41. Intermediate sleeve body; 411. Second mounting groove; 412. Oil groove; 42. Wear-resistant sleeve; 431. First sealing groove; 432. First sealing ring; 433. Second sealing groove; 434. Second sealing ring; 435. Third sealing groove; 436. Third sealing ring; 437. Fourth sealing ring; 51. Trapezoidal groove; 52. Second circumferential welded structure; 61. First groove; 611. First inclined inner wall; 612. First groove body; 62. Second groove; 621. Second inclined inner wall; 622. Second groove body; 63. Limiting snap ring; 71. Outer dust cover; 72. Inner dust cover. Detailed Implementation

[0037] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0038] Please see Figures 1 to 9 As shown, an adaptive nitrogen balancing cylinder of the present invention includes a hollow cylinder 1, an end cap 2 sealing one end of the cylinder 1, and a piston 3 reciprocatingly disposed within the cylinder 1. The piston 3 specifically comprises a piston rod 31 and a piston portion 32. The piston portion 32 is mounted at the end of the piston rod 31 that extends into the cylinder 1, thus forming a relatively closed high-pressure gas chamber 10 inside the cylinder 1 and effectively isolating the high-pressure gas chamber 10 from the external atmospheric environment. The other end of the piston rod 31 extends freely to the outside of the cylinder 1 for connection to an external load.

[0039] On the end cap 2, there is a pre-set inflation part 21 that is connected to the high-pressure air chamber 10. High-pressure nitrogen is injected into the high-pressure air chamber 10 through the inflation part 21 as an elastic medium.

[0040] In addition, an annular intermediate sleeve assembly 4 is fitted at the other end opening of the cylinder 1, and the free end of the piston rod 31 passes through the intermediate sleeve assembly 4 and continues to extend outward. Lubricating media are provided between the piston rod 31 and the cylinder 1, and between the piston rod 31 and the intermediate sleeve assembly 4, to reduce the friction of the reciprocating motion.

[0041] The intermediate sleeve assembly 4 mainly consists of an intermediate sleeve body 41, a wear-resistant sleeve 42, and a complex sealing structure. The interior of the intermediate sleeve body 41 has a limiting step, which is used to stop and abut against the piston part 32 when the piston rod 31 extends outward, thereby preventing the piston part 32 from disengaging from the cylinder 1 and playing a role in mechanical safety limiting.

[0042] Multiple wear-resistant sleeves 42 are provided and are respectively arranged between the piston 3 and the intermediate sleeve assembly 4, and between the piston 3 and the inner wall of the cylinder 1, to absorb radial friction and provide guidance.

[0043] The sealing structure provides a tight seal when the piston 3 moves at high frequency; at the same time, the sealing structure also has the function of blocking and scraping off excess lubricating medium on the surfaces of the piston 3, cylinder 1 and intermediate sleeve assembly 4.

[0044] When this balance cylinder is put into actual operation, the piston rod 31 moves relative to the cylinder 1 under the action of external load. At this time, the gas volume in the high-pressure gas chamber 10 will change from compression to expansion. Relying on the excellent compressibility of high-pressure nitrogen, the gas chamber will adaptively generate a reverse balance force that completely counteracts the current external load.

[0045] Compared to existing technologies that rely on complex electronic control systems or external hydraulic lines to achieve balance, this solution relies on a purely mechanical structure and the physical properties of high-pressure nitrogen, requiring no external power source. It has a simpler structure and is more stable and reliable in operation.

[0046] In this embodiment, the connection between the end cap 2 and the cylinder 1 adopts a sealed and reinforced structure.

[0047] Specifically, a stepped interlocking structure 5 is provided on the mating end face of the end cap 2 and the cylinder 1. This interlocking structure can achieve precise positioning and initial sealing of the two during assembly. At the same time, a trapezoidal groove 51 with a trapezoidal cross section is formed between the outer peripheral wall of the end cap 2 and the end of the cylinder 1.

[0048] In terms of the connection process, two circumferential welds were performed between the end cap 2 and the cylinder 1: The first circumferential weld is directly applied to the mating gap of the stepped interlocking structure 5. Through the penetration welding technology, the end cap 2 and the end of the cylinder 1 are melted and sealed together to withstand the high internal pressure brought by high-pressure nitrogen and ensure complete gas sealing. The second circumferential weld is directly placed inside the trapezoidal groove 51 and completely fills the entire trapezoidal groove 51. The structural characteristics of the trapezoidal groove 51 are used to form a thick weld bead, which greatly strengthens the connection between the end cover 2 and the cylinder 1.

[0049] Compared to the existing technology that uses a simple outer ring of welding rods after ordinary planar butt joint, this solution uses a stepped interlocking combination with trapezoidal groove 51 to fill the weld, which not only solves the problem of difficult centering and positioning of end cover 2 and cylinder 1, but also significantly improves the tensile strength and sealing failure risk under high pressure conditions, thus eliminating high pressure leakage at the end cover 2 position from the source.

[0050] Preferably, the cylinder body 1 is made of Q345 material.

[0051] This high-strength carbon structural steel ensures the basic structural strength of the cylinder body 1 to resist the internal expansion force of the high-pressure air chamber 10.

[0052] Specifically, after the inner hole of cylinder 1 is machined, the inner hole surface is also provided with a mirror layer formed by precision turning and grinding and polishing. The surface roughness Ra of the mirror layer is controlled in the range of 0.05 to 0.1.

[0053] In this embodiment, the preferred value is 0.08.

[0054] This extremely low roughness mirror layer can effectively reduce the resistance between the piston 3 and the inner wall of the cylinder 1 when the piston moves.

[0055] Preferably, the piston component 3, which consists of piston rod 31 and piston part 32, is formed by integral forging. This integral forging method avoids the risk of breakage that exists in welded or spliced ​​structures when subjected to several tons of high pressure.

[0056] To further improve the overall surface performance of piston component 3, the surface of piston component 3 is provided with a multi-layer structure from the inside to the outside: a tempering and hardening layer, a rough grinding layer, an ion nitriding layer, and the outermost fine grinding and polishing layer.

[0057] The surface roughness Ra of the outer circle of the finely ground and polished layer is controlled within the range of 0.02 to 0.05, preferably reaching 0.03.

[0058] Compared to the piston rod 31 that is directly assembled after ordinary machining in the existing technology, this solution adopts a specific layered processing technology, especially ion nitriding treatment. While retaining the toughness of the core, it greatly improves the surface hardness and corrosion resistance, ensuring that the surface of the piston rod 31 rarely suffers from scoring or scratches during high-frequency, high-pressure, and high-speed operation, thus significantly extending the service life of the seal.

[0059] Specifically, in this embodiment, the wear-resistant sleeve 42 is preferably a graphite copper sleeve with self-lubricating properties.

[0060] The wear-resistant sleeves 42 are arranged in a ring shape, and there are at least two of them. In order to achieve a stable installation of the wear-resistant sleeves 42, the outer wall of the piston part 32 is provided with a recessed first mounting groove 321, and the inner wall of the middle sleeve body 41 is provided with a recessed second mounting groove 411.

[0061] In the assembled state, the first wear-resistant sleeve 42 is directly embedded in the first mounting groove 321 of the piston part 32, and the outer surface of the wear-resistant sleeve 42 slides against the inner wall of the cylinder 1; the second wear-resistant sleeve 42 is embedded in the second mounting groove 411 of the middle sleeve body 41, and the inner wall of the wear-resistant sleeve 42 slides against the outer surface of the piston rod 31.

[0062] Preferably, there are two second mounting slots 411, which are arranged at intervals along the axial direction of the middle sleeve body 41, while the number of wear-resistant sleeves 42 is increased to three. Specifically, the first wear-resistant sleeve 42 is installed in the first mounting slot 321, the second wear-resistant sleeve 42 is installed in the innermost second mounting slot 411, and the third wear-resistant sleeve 42 is installed in the outermost second mounting slot 411.

[0063] Preferably, an annular oil groove 412 is also provided on the inner wall of the middle sleeve body 41, and the position of the oil groove 412 is exactly between the two second mounting grooves 411.

[0064] Compared to the existing technology that only sets a single sealing ring or gasket at the piston end, this solution introduces a graphite copper sleeve, combined with the unique arrangement of the first mounting groove 321 and the double second mounting grooves 411, and uses the annular oil groove 412 for structural isolation, providing obvious multi-directional anti-eccentric load support, which greatly reduces the risk of mechanical wear and jamming caused by eccentric load.

[0065] In this embodiment, the present invention also designs an anti-detachment limiting structure with double inclined surfaces and an inner arc groove, which is specifically designed to resist the thrust of up to several tons in the high-pressure air chamber 10 and prevent the middle sleeve assembly 4 from being pushed out of the cylinder 1 by the high-pressure gas.

[0066] Specifically, the anti-detachment limiting structure includes a first groove 61 opened along the circumferential direction on the inner wall of the cylinder 1 opening end, a second groove 62 arranged along the circumferential direction on the outer periphery of the middle sleeve body 41, and an annular limiting spring 63 embedded between the first groove 61 and the second groove 62.

[0067] Specifically, the first groove 61 is designed with a radially inwardly tapering first inclined inner wall 611 and an arc-shaped first groove 612, and the second groove 62 is designed with a radially inwardly tapering second inclined inner wall 621 and an arc-shaped second groove 622. In the natural state after assembly, the retaining spring 63 is simultaneously engaged in the first groove 612 and the second groove 622.

[0068] At this time, the middle sleeve assembly 4 and the other end of the cylinder 1 form a reverse engagement and hook-up through the anti-detachment limiting structure.

[0069] Compared to the existing anti-detachment structures that use a single vertical straight edge retaining groove or threaded cap, the design of the arc-shaped groove in this solution, where the first inclined inner wall 611 and the second inclined inner wall 621 are combined, ensures that when the equipment is subjected to a huge outward thrust from the high-pressure air chamber 10, the retaining spring 63 will be wedge-pressed by the inclined and arc surfaces, causing the retaining spring 63 to expand radially and become unable to slip out of the groove, thus forming a self-locking defense line and greatly improving safety.

[0070] Specifically, the design of the sealing structure directly determines whether high-pressure nitrogen can be maintained for a long time. The sealing structure includes a first sealing groove 431 formed along the circumferential direction on the outer wall of the middle sleeve body 41, a first sealing ring 432 embedded in the first sealing groove 431, and a second sealing groove 433 formed along the circumferential direction on the inner wall of the middle sleeve body 41, and a second sealing ring 434 embedded in the second sealing groove 433.

[0071] The opening direction of the first sealing groove 431 is completely opposite to the opening direction of the second sealing groove 433, thereby blocking the gas leakage path from both the inside and outside dimensions.

[0072] In terms of preferred materials, the first sealing ring 432 is an O-ring to achieve sealing under static or low frequency of activity; the second sealing ring 434 is a Y-ring, which utilizes the characteristics of the Y-shaped opening to automatically open and fit the sealing surface when subjected to high pressure.

[0073] Preferably, two first sealing rings 432 are provided. In the core area of ​​the sealing structure, an additional high-pressure leak prevention and oil scraping prevention line is added: a third sealing groove 435 is opened in the circumferential direction on the inner wall of the middle sleeve body 41, and a third sealing ring 436 and a fourth sealing ring 437 are arranged together in the third sealing groove 435. The two are arranged in the radial direction in the third sealing groove 435 and abut against each other and squeeze together.

[0074] The third sealing ring 436 has a circular cross-sectional shape, while the fourth sealing ring 437 has a square cross-sectional shape. The third sealing ring 436 and the fourth sealing ring 437 together constitute an additional one-way sealing unit.

[0075] After assembly, the inner wall of the square-section fourth sealing ring 437 directly abuts against the outer wall surface of the piston rod 31. Compared with the existing technology that only has a single sealing ring or O-ring, the multi-stage composite seal in this solution (O-ring, Y-ring combined with the round and square combination of the fourth sealing ring 437) not only forms multiple gas sealing barriers against high-pressure nitrogen, but also utilizes the square cross-section feature of the fourth sealing ring 437 to effectively scrape and block the lubricating medium that seeps out from the surface of the piston rod 31 when the piston rod 31 reciprocates, preventing the grease from forming gas locks or contaminating the nitrogen inside the high-pressure gas chamber 10, ultimately achieving the dual functions of gas sealing and oil scraping.

[0076] Preferably, in order to ensure the long-term working stability of the entire system in harsh environments, in this embodiment, an outer dust cover 71 is provided between the outer wall of the middle sleeve body 41 and the inner wall of the cylinder 1, and an inner dust cover 72 is provided between the inner wall of the middle sleeve body 41 and the outer surface of the piston rod 31.

[0077] The two sets of dust covers act as two barriers, effectively preventing dust, iron filings, or moisture from the external environment from penetrating the internal precision wear-resistant sleeve 42 and sealing structure.

[0078] In terms of the lubrication system, the lubricating medium of the present invention is preferably lithium-based grease, and more preferably lithium molybdenum disulfide grease.

[0079] The injection and distribution of grease adopts a specific structural design: oil injection holes or oil injection nozzles that connect to the internal friction surfaces are provided on the end cap 2, the middle sleeve body 41 or the piston rod 31. At the same time, the annular oil groove 412 opened on the inner wall of the middle sleeve body 41 is connected to the oil injection hole.

[0080] When assembly is complete or during routine maintenance, workers only need to use a grease gun to force the lithium-based grease into the grease injection hole. The grease will first flow to the lower level and fill the annular oil groove 412, forming an oil storage structure similar to a "grease reservoir".

[0081] During equipment operation, the grease in the oil groove 412 is continuously carried out and evenly applied between the graphite copper sleeve and the outer wall of the piston rod 31, and between the piston part 32 and the inner wall of the cylinder 1, driven by the reciprocating motion of the piston rod 31. Combining the self-lubricating properties of the graphite copper sleeve itself with the externally injected lithium-based grease, a robust dual lubrication system is finally formed between the friction pairs.

[0082] Compared to existing technologies that rely on periodic external spraying of lubricating oil, this solution achieves internal self-circulation of the lubricating medium and long-term lubrication, eliminating the hassle of frequent manual maintenance.

[0083] Preferably, in order to achieve sealed filling of high-pressure nitrogen, the filling part 21 adopts a specific layout of T-shaped holes and straight holes.

[0084] Specifically, the inflation section 21 includes a T-shaped first hole 211 and a straight second hole 212. The first hole 211 opens outward along the radial direction of the end cover 2, while the second hole 212 opens axially along the central axis of the end cover 2. The two are intersected and connected inside the end cover 2. The inner end of the second hole 212 is directly connected to the high-pressure air chamber 10 inside the cylinder 1.

[0085] During assembly, a valve core 213 is installed inside the outer port of the first hole 211 to achieve one-way inflation and prevent gas backflow. The outermost part of the first hole 211 is also provided with a plug sealing screw 214. By tightening the screw, the valve core 213 is subjected to external mechanical compression and physical sealing, achieving double safety and leak prevention after high-pressure inflation.

[0086] Preferably, the piston portion 32 is also provided with a plurality of air passage holes 322 communicating with the high-pressure gas chamber 10, and the plurality of air passage holes 322 are distributed in a uniform annular array around the central axis of the piston portion 32. When high-pressure nitrogen enters the high-pressure gas chamber 10 through the charging portion 21, it can act quickly and evenly on the end face of the piston portion 32 through these air passage holes 322, avoiding the influence of eccentric load caused by unidirectional impact on the stable operation of the piston component 3.

[0087] In the manufacturing process of this adaptive nitrogen balance cylinder, step S1 first involves material preparation and preliminary processing.

[0088] The cylinder barrel 1 and end cap 2 are preferably made of Q345 material, which has excellent comprehensive mechanical properties. For the cylinder barrel 1, which bears the internal high pressure, precision turning and grinding and polishing are carried out sequentially during the preparation of its inner hole to form a mirror layer. The surface roughness Ra of the mirror layer is controlled at about 0.08 to minimize the frictional resistance during reciprocating motion.

[0089] For the piston rod 31 that bears the reciprocating high-frequency motion, its blank is integrally forged to obtain a dense internal metal structure and avoid the risk of fracture caused by subsequent high-pressure impact.

[0090] After forging, the piston rod 31 is subjected to heat treatment, precision machining, rough grinding, ion nitriding, and final precision polishing in sequence. The heat treatment aims to improve its overall toughness, while the ion nitriding treatment forms a high-hardness nitriding layer on its surface. After fine grinding and polishing, the surface roughness Ra of the outer circle of the piston rod 31 reaches 0.03, and its surface forms a heat-hardened layer, a rough grinding layer, an ion nitriding layer, and a fine grinding and polishing layer from the inside to the outside in sequence.

[0091] Specifically, in the pre-assembly stage of step S2, the sealing and fixing connection between the end cap 2 and the cylinder 1 is involved. This process is the core of determining whether the high-pressure air chamber 10 can remain leak-free for a long time.

[0092] When the end cap 2 is sealed to one end of the cylinder 1, the end cap 2 and the cylinder 1 are first positioned by a pre-designed stepped interlocking structure 5, and at the same time, a trapezoidal groove 51 is naturally formed between the outer peripheral wall of the end cap 2 and the end of the cylinder 1.

[0093] During the formal welding process, two circumferential welds are performed: the first circumferential weld is applied directly to the mating gap of the stepped interlocking structure 5, using a penetration welding process to deeply fuse the bottom of the end cap 2 with the end of the cylinder 1, thus forming the primary line of defense for high-pressure sealing; the second circumferential weld is directly placed in the trapezoidal groove 51 and completely fills the trapezoidal groove 51 to form a thick reinforcing weld.

[0094] Compared to the existing technology that directly uses planar butt joints followed by single welding, the stepped interlocking structure 5 in this solution provides precise physical positioning and fitting. The combination of the trapezoidal groove 51 and the two welds not only ensures a more secure gas seal, but also provides strong tensile and shear strength when subjected to several tons of high pressure pushing outwards, significantly reducing the risk of pressure loss caused by weld cracking at the end cap 2 connection.

[0095] Preferably, in step S3, the middle sleeve body 41 needs to be precisely assembled. The wear-resistant sleeve 42 and the multiple sealing structures are pre-installed at the corresponding positions of the middle sleeve body 41.

[0096] During installation, the wear-resistant sleeve 42 is preferably a graphite copper sleeve, and the quantity is set to at least two according to structural requirements. A wear-resistant sleeve 42 is embedded in the first mounting groove 321 on the outer wall of the piston part 32, and the outer surface of the wear-resistant sleeve 42 is used to abut against the inner wall of the cylinder 1. Meanwhile, a wear-resistant sleeve 42 is also embedded in the second mounting groove 411 arranged on the inner wall of the middle sleeve body 41. The inner wall of the wear-resistant sleeve 42 slides against the outer surface of the piston rod 31. There are two second mounting grooves 411, which are arranged at intervals along the axial direction of the middle sleeve body 41. The three wear-resistant sleeves 42 are assembled accordingly: one is installed in the first mounting groove 321, another is installed in the inner second mounting groove 411, and the third is installed in the outer second mounting groove 411. An annular oil groove 412 is formed on the inner wall of the middle sleeve body 41 between the two second mounting grooves 411.

[0097] After the wear-resistant sleeve 42 is assembled, the sealing structure is installed simultaneously: a first sealing ring 432 is embedded in the first sealing groove 431 on the outer wall of the middle sleeve body 41, and a second sealing ring 434 is embedded in the second sealing groove 433 on the inner wall of the middle sleeve body 41. The openings of the first sealing groove 431 and the second sealing groove 433 are opposite, and the first sealing ring 432 is an O-ring, while the second sealing ring 434 is a Y-ring. The opening of the Y-ring faces the high-pressure air chamber 10 and is used to automatically open and seal when subjected to internal pressure.

[0098] More preferably, a third sealing ring 436 with a circular cross-section and a fourth sealing ring 437 with a square cross-section are jointly embedded in the third sealing groove 435. The two are arranged radially in sequence in the third sealing groove 435 and abut against each other and squeeze together. The fourth sealing ring 437 with a square cross-section is close to the outer wall of the piston rod 31.

[0099] Compared to the simple structure of existing technologies that rely on a single sealing ring for sealing, this solution provides a strong multi-stage sealing and locking capability through the reverse arrangement of multiple sealing rings in different directions inside and outside, as well as the unique axial and radial compression fit of circular and square sealing rings. At the same time, the edge structure of the square sealing ring can effectively scrape off backflowing oil, ensuring long-term stability of sealing performance.

[0100] Specifically, during the overall assembly in step S4, one end of the piston component 3 with the piston part 32 is inserted into the cylinder 1, and then the middle sleeve assembly 4 assembled in step S3 is fitted onto the piston rod 31 and pushed into the other end opening of the cylinder 1 for installation.

[0101] In particular, when assembling the sleeve component 4, an anti-disengagement limiting structure is used for locking: the assembler uses a special tool to radially retract the annular limiting spring 63 and place it in the first groove 61 pre-opened on the inner wall of the cylinder 1. Then, the middle sleeve body 41 is pushed into the open end of the cylinder 1. When the second groove 62 on the outer periphery of the middle sleeve body 41 is completely aligned with the first groove 61, the compression of the limiting spring 63 is released. The limiting spring 63 expands outward under its own elastic reset action and is simultaneously locked between the first groove 61 and the second groove 62.

[0102] At this time, the first groove 61, which is radially inwardly tapering towards the opening, and the first inclined inner wall 611 and the arc-shaped first groove 612, form a reverse engagement with the second groove 62, which is radially inwardly tapering towards the opening, and the second inclined inner wall 621 and the arc-shaped second groove 622.

[0103] During the assembly process, the outer dust cover 71 and the inner dust cover 72 are respectively placed between the outer wall of the middle sleeve body 41 and the inner wall of the cylinder 1, and between the inner wall of the middle sleeve body 41 and the outer surface of the piston rod 31.

[0104] Compared to existing technologies that rely solely on screwing the gland, this solution features a unique anti-disengagement limiting structure with double-inclined inner wall grooves and a limiting spring 63 working together. Under the pressure of several tons of high pressure pushing outward, the limiting spring 63 will exert a strong wedging effect due to the compression of the inclined inner wall, forming a physical self-locking. This completely eliminates the safety hazard of the middle sleeve assembly 4 and piston rod 31 being blown out by the high-pressure gas as a whole, greatly improving the safety of the machine under extreme working conditions.

[0105] Preferably, in step S5, the final construction of the high-pressure inflation and lubrication system is carried out.

[0106] In terms of lubrication, an oil injection hole or oil injection nozzle that connects to the internal friction surface is pre-opened on the connector of the end cap 2, the middle sleeve body 41 or the piston rod 31, and the annular oil groove 412 on the inner wall of the middle sleeve body 41 is connected to the oil injection hole.

[0107] During inflation and lubrication, the lubricating medium (preferably lithium-based grease) is first forcibly injected through the oil injection hole using an oil injection gun. The grease is preferentially filled into the annular oil groove 412 to form a pre-stored "grease reservoir".

[0108] In actual operation, the grease in the oil reservoir 412 is carried out when the piston rod 31 reciprocates and is evenly applied between the graphite copper sleeve and the piston rod 31. Combined with the self-lubricating properties of the graphite copper sleeve, dual lubrication is achieved, eliminating the need for frequent daily addition of lubricating oil.

[0109] Subsequently, high-pressure nitrogen gas is injected into the high-pressure gas chamber 10 from the inflation section 21 of the end cap 2 using a high-pressure gas inflation device. The inflation section 21 specifically includes a T-shaped first hole 211 and a straight second hole 212. The first hole 211 is opened radially along the end cap 2, and the second hole 212 is opened axially along the end cap 2 and located at the central axis. The two are intersecting and connected.

[0110] After high-pressure nitrogen enters the high-pressure gas chamber 10 through the gas filling part 21, when the piston rod 31 moves under the action of external load, it generates an adaptive reverse balance force by relying on the compressibility of high-pressure gas. At the same time, the multiple gas passage holes 322 arranged in a ring on the piston part 32 enable the high-pressure nitrogen to act evenly on the end face of the piston part 32, preventing the occurrence of off-center load.

[0111] Compared to existing technologies that rely on external complex pressure balancing valves for compensation, this solution achieves maintenance-free lubrication and long-term stable storage of high-pressure gas with zero leakage through a self-supply grease system with a built-in oil groove 412 and an air injection structure that combines a T-hole with a valve core 213 and a plug sealing screw 214, greatly reducing the later maintenance costs of the equipment.

[0112] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any indirect modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An adaptive nitrogen balance cylinder, characterized in that: The device includes a hollow cylinder (1), an end cap (2) located at one end of the cylinder (1), and a piston (3) that is reciprocally disposed within the cylinder (1). The piston (3) includes a piston rod (31) and a piston portion (32). The piston portion (32) extends into the cylinder (1) to form a high-pressure gas chamber (10) within the cylinder (1) and to isolate the high-pressure gas chamber (10) from the external environment. The piston rod (31) extends to the outside of the cylinder (1). The end cap (2) is provided with an inflation part (21) that communicates with the high-pressure gas chamber (10). High-pressure nitrogen is injected into the high-pressure gas chamber (10) through the inflation part (21). It also includes an annular intermediate sleeve assembly (4) disposed between the other end of the cylinder (1) and the piston rod (31); the free end of the piston rod (31) extends through the intermediate sleeve assembly (4) to the outside of the cylinder (1); lubricating media are provided between the piston rod (31) and the cylinder (1) and between the piston rod (31) and the intermediate sleeve assembly (4); the intermediate sleeve assembly (4) includes an intermediate sleeve body (41), a wear-resistant sleeve (42) and a sealing structure, the intermediate sleeve body (41) is used to stop and abut against the piston part (32) to limit the piston part (32) from coming out of the cylinder (1), the wear-resistant sleeve (42) 42) The sealing structure is provided between the piston (3) and the middle sleeve assembly (4) and between the piston (3) and the inner wall of the cylinder (1). It is used to provide a seal when the piston (3) moves back and forth, and to block and scrape the lubricating medium on the surfaces of the piston (3), cylinder (1) and middle sleeve assembly (4). When the piston rod (31) moves relative to the cylinder (1) under the action of external load, the gas volume in the high pressure gas chamber (10) changes from compression to expansion. The compressibility of the high pressure gas adaptively generates a reverse balancing force to counteract the current external load.

2. The adaptive nitrogen balance cylinder according to claim 1, characterized in that: A stepped interlocking structure (5) is provided between the end cap (2) and the cylinder (1); a trapezoidal groove (51) is formed between the outer peripheral wall of the end cap (2) and the end of the cylinder (1); two circumferential welded structures are provided between the end cap (2) and the cylinder (1). The first circumferential welded structure is located at the mating gap of the stepped interlocking structure (5) and is used to melt and seal the end of the end cap (2) and the cylinder (1); the second circumferential welded structure (52) is set in the trapezoidal groove (51) and fills the trapezoidal groove (51) to strengthen the bonding strength between the end cap (2) and the cylinder (1).

3. The adaptive nitrogen balance cylinder according to claim 1, characterized in that: The cylinder (1) is made of Q345 material. The inner surface of the cylinder (1) is provided with a mirror layer that has been precision machined and polished. The surface roughness Ra of the mirror layer is 0.05-0.

1.

4. The adaptive nitrogen balance cylinder according to claim 1, characterized in that: The piston part (3) is formed by integral forging. The surface of the piston part (3) is provided with a tempering and hardening layer, a rough grinding layer, an ion nitriding layer and a fine grinding and polishing layer from the inside to the outside. The surface roughness Ra of the outer circle of the fine grinding and polishing layer is 0.02-0.

05.

5. The adaptive nitrogen balance cylinder according to claim 1, characterized in that: The wear-resistant sleeve (42) is arranged in a ring shape, and there are at least two wear-resistant sleeves (42); the outer wall of the piston part (32) is provided with a first mounting groove (321), and the inner wall of the middle sleeve body (41) is provided with a second mounting groove (411); the first wear-resistant sleeve (42) is installed in the first mounting groove (321), and the outer surface of the first wear-resistant sleeve (42) abuts against the inner wall of the cylinder (1); the second wear-resistant sleeve (42) is arranged in the second mounting groove (411), and the outer wall of the second wear-resistant sleeve (42) abuts against the outer surface of the piston rod (31).

6. The adaptive nitrogen balance cylinder according to claim 1, characterized in that: It also includes an anti-detachment limiting structure; the anti-detachment limiting structure includes a first groove (61) opened in the circumferential direction on the inner wall of the cylinder (1), a second groove (62) arranged in the circumferential direction on the outer periphery of the middle sleeve body (41), and a limiting spring (63) located between the first groove (61) and the second groove (62); the first groove (61) has a radially inwardly tapered first inclined inner wall (611) and an arc-shaped first groove (612), and the second groove (62) has a radially inwardly tapered second inclined inner wall (621) and an arc-shaped second groove (622); the limiting spring (63) is arranged in a ring shape and is embedded in the first groove (612) and the second groove (622); the other end of the middle sleeve assembly (4) and the cylinder (1) are engaged and hooked in reverse by the anti-detachment limiting structure in the assembled state.

7. The adaptive nitrogen balance cylinder according to claim 1, characterized in that: The sealing structure includes a first sealing groove (431) opened in the circumferential direction on the outer wall of the middle sleeve body (41), a first sealing ring (432) disposed in the first sealing groove (431), a second sealing groove (433) opened in the circumferential direction on the inner wall of the middle sleeve body (41), and a second sealing ring (434) disposed in the second sealing groove (433); the opening direction of the first sealing groove (431) is opposite to the opening direction of the second sealing groove (433); the first sealing ring (432) is an O-ring, and the second sealing ring (434) is a Y-ring.

8. The adaptive nitrogen balance cylinder according to claim 1, characterized in that: The sealing structure also includes a third sealing groove (435) opened in the inner wall of the middle sleeve body (41) along the circumferential direction, a third sealing ring (436) and a fourth sealing ring (437) arranged together in the third sealing groove (435); the cross section of the third sealing ring (436) is circular, the cross section of the fourth sealing ring (437) is square, the third sealing ring (436) and the fourth sealing ring (437) are arranged radially in the third sealing groove (435) and they abut against each other and squeeze together, and the inner wall of the fourth sealing ring (437) is used to abut against the outer wall of the piston rod (31).

9. A method for manufacturing an adaptive nitrogen balance cylinder, used to manufacture the adaptive nitrogen balance cylinder according to any one of claims 1-8, characterized in that, Includes the following steps: S1, Material preparation: manufacture end cap (2), cylinder (1), piston (3) and middle sleeve assembly (4), and provide lubricating medium and high pressure gas charging equipment. The cylinder (1) is hollow. The end cap (2) is provided with a charging part (21) connected to the hollow part of the cylinder (1). The middle sleeve assembly (4) includes middle sleeve body (41), wear-resistant sleeve (42) and sealing structure. S2, Pre-assembly: The end cap (2) is sealed and fixedly connected to one end of the cylinder (1), so that one end of the cylinder (1) is sealed and the other end forms a chamber for installing the middle sleeve assembly (4) and the piston (3); S3, Assembly of the middle sleeve assembly (4): The wear-resistant sleeve (42) and the sealing structure are respectively installed at the corresponding positions of the middle sleeve body (41) to form an annular middle sleeve assembly (4). S4, overall assembly: Insert one end of the piston part (3) with the piston part (32) into the cylinder (1), put the middle sleeve assembly (4) of step S3 onto the piston rod (31) and install it at the other end opening of the cylinder (1) to block the other end opening of the cylinder (1), so that a high-pressure air chamber (10) communicating with the air filling part (21) is formed inside the cylinder (1); let the other end of the piston rod (31) pass through the middle sleeve assembly (4) and extend to the outside of the cylinder (1), and form a sealed sliding fit between the piston rod (31) and the cylinder (1) through the sealing structure and lubricating medium; S5, filling with high-pressure gas: using a high-pressure gas filling device to inject high-pressure gas into the high-pressure gas chamber (10) from the filling part (21) of the end cover (2); when the piston rod (31) moves relative to the cylinder (1) under the action of external load, the gas volume in the high-pressure gas chamber (10) changes from compression to expansion, and by relying on the compressibility of high-pressure gas, an adverse balancing force is generated to counteract the current external load.

10. The manufacturing method of the adaptive nitrogen balance cylinder according to claim 9, characterized in that: In step S1, the inner hole of the cylinder (1) is machined by precision turning followed by grinding and polishing, so that the surface roughness Ra of the inner hole of the cylinder (1) after grinding and polishing reaches 0.08; the piston rod (31) is processed by tempering, precision turning, rough grinding, ion nitriding and fine grinding and polishing, so that the surface roughness Ra of the outer circle of the piston rod (31) reaches 0.03.

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