Hydraulic drive piston compressor with hydraulic cylinder in the middle

Abstract

The utility model provides a kind of hydraulic drive piston type compressor of hydraulic cylinder in middle, main body is multiple cylinder coaxial series connection structure, middle is equipped with hydraulic cylinder module, left pressure-increasing cylinder module is equipped in the left side of the hydraulic cylinder module, right pressure-increasing cylinder module is equipped in the right side, the hydraulic cylinder module with left pressure-increasing cylinder module, right pressure-increasing cylinder module is independent detachable structure, module is connected by flange and screw rod, without long pull rod that all cylinder body is penetrated, without disassembling all cylinder body, the individual replacement or maintenance of pressure-increasing cylinder module can be realized.

Description

Technical Field

[0001] This utility model relates to the field of compressor technology, specifically to a hydraulically driven piston compressor with a hydraulic cylinder in the middle. Background Technology

[0002] The liquid-driven reciprocating compressor is a widely used compressor. It offers the following advantages: 1) It can frequently start and stop under load; 2) It is suitable for various applications such as hydrogen refueling stations, laboratories, and testing facilities; 3) It has a wide range of input and output pressures, with input pressure as low as 0.5 MPa and output pressure as high as 200-300 MPa; 4) Its displacement can be large or small, such as a hydrogen compressor for a hydrogen refueling station with a displacement of up to 1500 Nm³ / h; 5) It provides safe and effective oil-gas sealing and isolation; 6) It is easy, quick, labor-saving, and economical to install and maintain. Due to these features and advantages, this type of compressor is receiving increasing attention.

[0003] The related technology discloses a hydraulically driven three-stage compression cylinder, employing a series structure of two hydraulic cylinders and three air cylinders. The two hydraulic cylinders are located on either side, and the three air cylinders (first, second, and third cylinders) are positioned between the two hydraulic cylinders, with the inner diameter of the cylinders decreasing sequentially (first cylinder > second cylinder > third cylinder), forming a three-stage compression. All cylinder bodies (hydraulic cylinders + air cylinders) are axially fixed into a single structure by multiple connecting rods and locking nuts, with the connecting rods penetrating all cylinder bodies and partitions. Although this related technology has advantages such as high gas compression efficiency and large exhaust volume, it still has the following drawbacks in practical use:

[0004] First, the assembly and maintenance are inconvenient. The compressor's main seal is an axial dynamic seal, which needs to be replaced after reaching its lifespan to maintain good sealing performance. Therefore, the compressor requires regular disassembly, maintenance, and assembly. In this related technology, all cylinders (oil cylinder + air cylinder) are axially fixed as a single unit by multiple connecting rods and locking nuts. The connecting rods run through all cylinders and partitions, without any detachable modular divisions. Once the nuts are removed, all axially connected components will scatter. During reassembly, the coaxiality of each cylinder must be adjusted individually, and each component must be placed in sequence and connected in series. This results in low disassembly and assembly efficiency and wastes time. Especially when applied in hydrogen refueling station scenarios, this will extend maintenance time and is detrimental to the economics of hydrogen refueling stations.

[0005] Second, it has limited functionality. This technology is fixed to one compression mode. If the displacement needs to be adjusted, the entire compressor cylinder assembly or even the entire device needs to be replaced. It has limited functionality and poor adaptability.

[0006] Third, the cooling design is not targeted enough, and the effectiveness of the seals is poor. The cooling water jacket of this related technology is only provided on the outside of the first and / or second oil cylinders, and the cooling object is only the cylinder body. The end cover seal between the cylinder and the oil cylinder is in an environment of "compression heat release and friction heat generation" for a long time, which makes the seals prone to failure. Utility Model Content

[0007] The purpose of this invention is to provide a hydraulically driven piston compressor with a hydraulic cylinder in the middle, aiming to solve the technical problem of poor ease of disassembly and assembly of hydraulically driven piston compressor cylinders in related technologies.

[0008] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

[0009] According to a first aspect of this utility model, a hydraulically driven piston compressor with a hydraulic cylinder in the middle is provided. The main body is a multi-cylinder coaxial series structure with a hydraulic cylinder module in the middle. A left booster cylinder module is provided on the left side of the hydraulic cylinder module, and a right booster cylinder module is provided on the right side. The hydraulic cylinder module, the left booster cylinder module, and the right booster cylinder module are independent and detachable structures. The modules are connected by flanges and screws. There is no long tie rod penetrating all cylinders. The booster cylinder module can be replaced or maintained individually without disassembling all cylinders.

[0010] The hydraulically driven piston compressor with the hydraulic cylinder in the middle provided by the exemplary embodiment of this utility model is different from the "integrated structure of all cylinders fixed by a long tie rod" in related technologies. This utility model has an independent and detachable modular design. During maintenance, only the booster cylinder module to be maintained needs to be disassembled, while the core components of the hydraulic cylinder remain intact, which greatly shortens the maintenance time and reduces the difficulty of operation.

[0011] In an exemplary embodiment of this utility model, the main body is a three-cylinder coaxial series structure, and the left booster cylinder module and the right booster cylinder module are both modules containing one booster cylinder;

[0012] The hydraulic cylinder module is defined as the second module, and the left booster cylinder module and the right booster cylinder module are selected as either the first module or the third module;

[0013] The second module includes a hydraulic inner end cap sealing assembly, a hydraulic inner end cap, a hydraulic cylinder body, a piston rod, a hydraulic cylinder piston sealing assembly, and a hydraulic cylinder piston. The hydraulic cylinder piston divides the inner cavity of the hydraulic cylinder body into a hydraulic left cavity and a hydraulic right cavity. The inner sides of the piston rods on both sides of the hydraulic cylinder piston are connected to the hydraulic cylinder piston, and the outer sides are in contact with the booster cylinder pistons in the left and right booster cylinder modules, respectively, so that the hydraulic cylinder piston, the left booster cylinder piston, the right booster cylinder piston, and the two piston rods move synchronously left and right in a linear motion.

[0014] The first module includes an outer end cap, a D1 outer end cap, a D1 booster cylinder body, a D1 piston sealing assembly, a D1 booster cylinder piston, a D1 inner end cap, and a D1 inner end cap sealing assembly.

[0015] The third module includes an outer end cap, a D2 outer end cap, a D2 booster cylinder body, a D2 piston sealing assembly, a D2 booster cylinder piston, a D2 inner end cap, and a D2 inner end cap sealing assembly. The D1 booster cylinder body and the D2 booster cylinder body have different inner diameters.

[0016] By changing the type of the left and right booster cylinder modules, a dual-cylinder single-stage compression mode or a single-cylinder two-stage compression mode can be selectively implemented. The dual-cylinder single-stage compression mode is in which both the left and right booster cylinder modules are either the first module or both are the third module. The single-cylinder two-stage compression mode is in which one of the left and right booster cylinder modules is the first module and the other is the third module.

[0017] The hydraulically driven piston compressor with the hydraulic cylinder in the middle provided by the exemplary embodiment of this utility model can flexibly switch the compression mode by replacing the booster cylinder module, adapting to the needs of multiple scenarios such as high pressure and large displacement, without the need to purchase multiple devices, reducing equipment investment costs, and solving the core defect of single function in related technologies.

[0018] In an exemplary embodiment of this utility model, the first module further includes a D1 water jacket, and the third module further includes a D2 water jacket; the D1 water jacket covers the outside of the D1 booster cylinder body, and the D2 water jacket covers the outside of the D2 booster cylinder body; the inner sides of the D1 water jacket and the D2 water jacket are both in contact with the outer wall of the corresponding booster cylinder body, and the D1 water jacket and the D2 water jacket are both provided with cooling water channels.

[0019] The tight fit between the water jacket and the cylinder body can effectively remove the heat generated by the cylinder body during compression, preventing the cylinder body from deforming or being damaged due to high temperature and extending the cylinder body's lifespan. At the same time, it reduces the temperature of the compression medium inside the cylinder body, reducing the impact of temperature on compression efficiency. Related technologies only cool the oil cylinder body and cannot solve the heat dissipation problem of the air cylinder body. This utility model can make up for this deficiency.

[0020] In an exemplary embodiment of this utility model, the side of the hydraulic inner end cap and the side of the inner end cap D1 or D2 are provided with water channels. The water channels are arranged around the sealing assembly of the inner hole of the end cap, and cooling water can be introduced into the water channels.

[0021] In an exemplary embodiment of this utility model, the water channel of the hydraulic inner end cover is connected to the water channel of the inner end cover D1 or the inner end cover D2 to form a continuous cooling water channel; the inlet of the continuous cooling water channel is located on the inner end cover D1 or the inner end cover D2 on one side, and the outlet is located on the inner end cover D1 or the inner end cover D2 on the other side.

[0022] Unlike related technologies that only cool the cylinder body, this utility model's water channel specifically cools the sealing components, reducing their operating temperature and preventing them from failing due to prolonged high-temperature aging. This extends their lifespan, reduces replacement frequency and maintenance costs, improves sealing reliability, and lowers the risk of media leakage. The continuous cooling water channel ensures synchronized cooling of all sealing components, preventing temperature differences caused by uneven cooling and further extending their lifespan. It also reduces the number of cooling pipe connections, lowers the risk of pipe leaks, and simplifies the cooling system structure.

[0023] In an exemplary embodiment of this utility model, the piston of the D1 booster cylinder divides the inner cavity of the D1 booster cylinder body into an outer D1 working chamber and an inner D1 isolation chamber; the piston of the D2 booster cylinder divides the inner cavity of the D2 booster cylinder body into an outer D2 working chamber and an inner D2 isolation chamber; the D1 isolation chamber and the D2 isolation chamber are used to isolate the compression medium of the corresponding working chamber from the hydraulic oil of the hydraulic cylinder module.

[0024] In an exemplary embodiment of this utility model, a fourth module is formed by adding either an inner end cap D1 or an inner end cap D2 to one of the two sides of the hydraulic cylinder module. The fourth module is a maintenance-specific module. When it is necessary to replace the seals of the left and right booster cylinder modules, the fourth module remains intact and is not disassembled. Only the booster cylinder module to be replaced is removed from the fourth module and disassembled.

[0025] The design of the fourth module eliminates the need to disassemble the core hydraulic drive components (hydraulic cylinder, piston rod, etc.) during maintenance, avoiding the problem of "dispersed and easily damaged hydraulic components after the pull rod is removed" in related technologies, thus reducing the risk of hydraulic system failure. At the same time, it significantly shortens maintenance time, making it particularly suitable for scenarios such as hydrogen refueling stations that are sensitive to downtime, reducing operational losses caused by downtime.

[0026] In an exemplary embodiment of this utility model, when both sides of the second module are simultaneously the first module or the third module, when oil enters the hydraulic left chamber and exits the hydraulic right chamber, the piston of the hydraulic cylinder moves linearly to the right, driving the piston of the booster cylinder module of the right booster cylinder module to move outward to reduce the working chamber volume and achieve pressurization, while driving the piston of the booster cylinder module of the left booster cylinder module to move inward to expand the working chamber volume and achieve air intake; when oil enters the hydraulic right chamber and exits the hydraulic left chamber, the piston of the hydraulic cylinder moves linearly to the left, driving the piston of the booster cylinder module of the left booster cylinder module to move outward to reduce the working chamber volume and achieve pressurization, while driving the piston of the booster cylinder module of the right booster cylinder module to move inward to expand the working chamber volume and achieve air intake;

[0027] When the second module is positioned with the first module on the left and the third module on the right, and the inner diameter d1 of the D1 booster cylinder of the first module is greater than the inner diameter d2 of the D2 booster cylinder of the third module, when oil enters the right hydraulic chamber and exits the left hydraulic chamber, the piston of the hydraulic cylinder moves linearly to the left, causing the piston of the booster cylinder of the left D1 booster cylinder module to move outward to reduce the working chamber volume. This allows compressed gas to be transported from the working chamber of the D1 booster cylinder through the intermediate pipeline and drawn into the working chamber of the D2 booster cylinder of the right D2 booster cylinder module, where the gas is compressed to the interstage pressure. When oil enters the left hydraulic chamber and exits the right hydraulic chamber, the piston of the hydraulic cylinder moves linearly to the right, causing the piston rod of the D2 booster cylinder to move outward to reduce the working chamber volume. The gas is further compressed to achieve secondary compression. At the same time, the piston of the left D1 booster cylinder moves inward to expand the working chamber of the D1 booster cylinder to achieve air intake.

[0028] In an exemplary embodiment of this utility model, the main body is a five-cylinder coaxial series structure, and the left booster cylinder module and the right booster cylinder module are both modules containing two-stage booster cylinders;

[0029] The hydraulic cylinder module is defined as the second module, and the left booster cylinder module and the right booster cylinder module are selected as either the fifth module or the sixth module;

[0030] The second module includes a hydraulic inner end cap sealing assembly, a hydraulic inner end cap, a hydraulic cylinder body, a piston rod, a hydraulic cylinder piston sealing assembly, and a hydraulic cylinder piston. The hydraulic cylinder piston divides the inner cavity of the hydraulic cylinder body into a hydraulic left cavity and a hydraulic right cavity. The inner sides of the piston rods on both sides of the hydraulic cylinder piston are connected to the hydraulic cylinder piston, and the outer sides are in contact with the booster cylinder pistons in the left and right booster cylinder modules, respectively, so that the hydraulic cylinder piston, the left booster cylinder piston, the right booster cylinder piston, and the two piston rods move synchronously left and right in a linear motion.

[0031] The fifth module is a booster cylinder module with an inner diameter of d1 for the first-stage booster cylinder and an inner diameter of d2 for the second-stage booster cylinder, where d1 > d2; the first module includes a D1 inner end cap sealing assembly, a D1 inner end cap, a D1 booster cylinder body, a D1 water jacket, a D1 piston seal, a D1 booster cylinder piston, a D1-D2 inter-end cap seal, a D1-D2 inter-end cap, a booster piston rod, a D2 booster cylinder body, a D2 piston sealing assembly, a D2 water jacket, a D2 booster cylinder piston, and a D2 outer end cap, where the inner diameter d1 of the D1 booster cylinder body is greater than the inner diameter d2 of the D2 booster cylinder body;

[0032] The sixth module is a booster cylinder module with an inner diameter of d3 for the first-stage booster cylinder and an inner diameter of d4 for the second-stage booster cylinder, where d3 > D4; the third module includes a D3 inner end cap sealing assembly, a D3 inner end cap, a D3 booster cylinder body, a D3 water jacket, a D3 piston seal, a D3 booster cylinder piston, a D3-D4 inter-end cap seal, a D3-D4 inter-end cap, a booster piston rod, a D4 booster cylinder body, a D4 piston sealing assembly, a D4 water jacket, a D4 booster cylinder piston, and a D4 outer end cap, where the inner diameter d3 of the D3 booster cylinder body is greater than the inner diameter d4 of the D4 booster cylinder body;

[0033] By changing the type of the left and right booster cylinder modules, a dual-cylinder dual-stage compression mode or a single-cylinder four-stage compression mode can be selectively implemented. The dual-cylinder dual-stage compression mode is that both the left and right booster cylinder modules are either the fifth module or both are the sixth module. The single-cylinder four-stage compression mode is that the left booster cylinder module is the fifth module and the right booster cylinder module is the sixth module, d1>d3>d2>d4.

[0034] By using a five-cylinder coaxial series design and a two-stage booster cylinder module, compared with the single-stage / two-stage compression of related technologies, this utility model can realize two core modes: dual-cylinder two-stage (large displacement) or single-cylinder four-stage (ultra-high pressure). It can adapt to different scenarios (such as the large displacement requirements of large hydrogen refueling stations and the requirements of ultra-high pressure detection) without replacing the entire equipment, thus improving the expandability of equipment functions.

[0035] In an exemplary embodiment of this utility model, the D1 water jacket of the fifth module is located outside the D1 booster cylinder body, and the D2 water jacket is located outside the D2 booster cylinder body; the D3 water jacket of the third module is located outside the D3 booster cylinder body, and the D4 water jacket is located outside the D4 booster cylinder body; the inner side of each water jacket is in contact with the outer wall of the corresponding booster cylinder body, and each water jacket is provided with a cooling water channel, through which cooling water can be introduced to cool the booster cylinder body.

[0036] The water jacket cooling system is specifically designed for the booster cylinder. Compared to the single water jacket design in related technologies, this utility model uses a dual water jacket layout of "first-stage cylinder + second-stage cylinder" to accurately remove the heat generated by each stage of compression, preventing the cylinder from overheating and deforming due to continuous boosting, extending the cylinder's lifespan, and ensuring stable temperature of the compressed medium, thus avoiding the impact of excessive temperature on compression efficiency or medium properties.

[0037] In an exemplary embodiment of this utility model, the D1 booster cylinder piston divides the inner cavity of the D1 booster cylinder body into an outer D1 working chamber and an inner D1 isolation chamber; the D2 booster cylinder piston divides the inner cavity of the D2 booster cylinder body into an outer D2 working chamber and an inner D2 isolation chamber; the D3 booster cylinder piston divides the inner cavity of the D3 booster cylinder body into an outer D3 working chamber and an inner D3 isolation chamber; the D4 booster cylinder piston divides the inner cavity of the D4 booster cylinder body into an outer D4 working chamber and an inner D4 isolation chamber; each isolation chamber is used to isolate the compression medium of the corresponding working chamber from the hydraulic oil of the hydraulic cylinder module.

[0038] By using a dual-chamber design of "working chamber + isolation chamber", compared with the single isolation measures in related technologies, this utility model can achieve multi-stage isolation between the compressed medium and the hydraulic oil, avoiding the leakage of flammable, explosive or high-purity media such as hydrogen into the hydraulic system, while preventing hydraulic oil from mixing into the compressed medium, improving equipment safety and medium purity, and meeting the needs of high-risk or high-precision scenarios such as hydrogen refueling stations and laboratories.

[0039] In an exemplary embodiment of this utility model, water channels are provided on the side of the hydraulic inner end cap, the side of the D1 inner end cap of the fifth module, and the side of the D3 inner end cap of the sixth module. The water channels are arranged around the sealing component of the inner hole of the end cap, and cooling water can be introduced to cool the end cap and the sealing component, ensuring that the non-metallic seal does not overheat and maintaining the sealing effect.

[0040] This invention features a water tank cooling system specifically designed for the end cap sealing assembly. Unlike related technologies that do not provide targeted sealing cooling, this invention can control the temperature of non-metallic seals within a safe range, preventing aging and failure of seals due to frictional heat generation and compression heat release, extending the lifespan of seals, reducing the risk of media leakage due to seal failure, and improving the operational stability of equipment.

[0041] In an exemplary embodiment of this utility model, the water channel of the hydraulic inner end cover is connected to the water channel of the inner end cover D1 or the inner end cover D3 to form a continuous cooling water channel; the inlet of the continuous cooling water channel is located on the inner end cover D1 or the inner end cover D3 on one side, and the outlet is located on the inner end cover D1 or the inner end cover D3 on the other side, so as to realize the synchronous cooling of the sealing components.

[0042] By using a continuous cooling water flow channel design, compared to the layout of independent cooling pipes in related technologies, this utility model can achieve synchronous cooling of the sealing components of the hydraulic cylinder end cover and the booster cylinder end cover, avoiding overheating of local seals due to uneven cooling, improving cooling uniformity, reducing the number of cooling pipe interfaces, reducing the risk of pipe leakage, and simplifying the cooling system structure.

[0043] In an exemplary embodiment of this utility model, a fourth module is formed by adding either an inner end cap D1 or an inner end cap D3 to one of the two sides of the hydraulic cylinder module. The fourth module is a maintenance-specific module. When it is necessary to replace the seals of the left and right booster cylinder modules, the fourth module remains intact and is not disassembled. Only the booster cylinder module to be replaced is removed from the fourth module and disassembled to replace the corresponding sealing component.

[0044] This utility model features a specially designed hydraulic cylinder module. Compared to related technologies that require disassembling hydraulic cylinder components for maintenance, this utility model can keep the core components of the hydraulic cylinder intact during maintenance, avoiding damage to the hydraulic system or the introduction of impurities due to disassembly. This reduces the risk of hydraulic system failure and significantly shortens maintenance time (from several hours to within 1 hour), making it particularly suitable for scenarios sensitive to downtime, such as peak hours at hydrogen refueling stations.

[0045] In an exemplary embodiment of this utility model, when both sides of the second module are simultaneously fifth modules: hydraulic oil enters from the left hydraulic chamber and hydraulic oil exits from the right hydraulic chamber, the hydraulic cylinder piston moves linearly to the right, driving the D1 booster cylinder piston and D2 booster cylinder piston of the right fifth module to move outward, the volume of the D1 working chamber and D2 working chamber decreases, realizing first-level and second-level boosting respectively, and simultaneously driving the D1 booster cylinder piston and D2 booster cylinder piston of the left fifth module to move inward and linearly to the left, driving the D1 booster cylinder piston and D2 booster cylinder piston of the left fifth module to move outward, and simultaneously driving the D1 booster cylinder piston and D2 booster cylinder piston of the right fifth module to move inward, realizing first-level and second-level intake.

[0046] With its dual-cylinder, dual-stage synchronous motion design, this invention achieves simultaneous dual-stage compression of gas from two different channels, compared to single-cylinder, single-stage / two-stage compression in related technologies. This increases displacement, and the intake and pressurization processes alternate continuously without compression interruption, thus improving compression efficiency and meeting the high-displacement gas requirements of large-scale hydrogen refueling stations.

[0047] In an exemplary embodiment of this utility model, when the left side of the second module is the fifth module and the right side is the sixth module, and d1>d3>d2>d4: hydraulic oil enters the right chamber and hydraulic oil exits the left chamber, the hydraulic cylinder piston moves linearly to the left, the piston of the D1 booster cylinder of the left fifth module moves outward, the volume of the D1 working chamber decreases, and gas enters the outer working chamber of the D3 booster cylinder of the right sixth module through the external interstage pipeline to achieve first-stage boosting; the piston of the D2 booster cylinder of the left fifth module moves outward, the volume of the D2 working chamber decreases, and gas enters the outer working chamber of the D4 booster cylinder of the right sixth module through the external interstage pipeline to achieve third-stage boosting. Oil enters from the left hydraulic chamber and exits from the right hydraulic chamber. The piston of the hydraulic cylinder moves linearly to the right. The volume of the outer working chamber of the D1 booster cylinder in the fifth left module increases, and air is drawn in from the outside. The volume of the outer working chamber of the D3 booster cylinder in the sixth right module decreases, and gas enters the outer working chamber of the D2 booster cylinder in the fifth left module from this chamber, achieving secondary boosting. The volume of the outer working chamber of the D4 booster cylinder in the sixth right module decreases, achieving quaternary boosting, and the ultra-high pressure gas is discharged from the compressor.

[0048] By using a single-cylinder four-stage compression design, compared to the method in related technologies that requires multiple devices to be connected in series to achieve ultra-high pressure, this utility model can achieve four-stage stepped pressurization with one device, increasing the output pressure to 200-300MPa. No additional devices are required to connect in series, reducing the equipment footprint and energy consumption. At the same time, the pressure is increased step by step to avoid the sealing failure problem caused by excessive single-stage compression pressure.

[0049] In an exemplary embodiment of this utility model, a gas channel from left to right is provided between the working chamber of the D1 booster cylinder of the left fifth module and the working chamber of the D3 booster cylinder of the right sixth module, so as to realize the transportation of gas after primary boosting to the secondary booster chamber; a gas channel from right to left is provided between the working chamber of the D3 booster cylinder of the right sixth module and the working chamber of the D2 booster cylinder of the left fifth module, so as to realize the transportation of gas after secondary boosting to the tertiary booster chamber; a gas channel from left to right is provided between the working chamber of the D2 booster cylinder of the left fifth module and the working chamber of the D4 booster cylinder of the right sixth module, so as to realize the transportation of gas after tertiary boosting to the quaternary booster chamber.

[0050] In an exemplary embodiment of this utility model, the outer end cap D2 of the fifth module and the outer end cap D4 of the sixth module are both provided with an air inlet channel, an air outlet channel, and a control valve. In the dual-cylinder dual-stage mode, the raw material gas is drawn in through the air inlet channel of the outer end cap D2 or the outer end cap D4, and the compressed gas is discharged through the air outlet channel. In the single-cylinder four-stage mode, the raw material gas is drawn in through the air inlet channel of the outer end cap D2 of the left fifth module, and the gas compressed in four stages is discharged through the air outlet channel of the outer end cap D4 of the right sixth module.

[0051] By integrating a gas channel in the end cap, compared to the design in related technologies that requires additional external pipelines to transport gas, this utility model simplifies the pipeline layout, reduces gas flow resistance and leakage points, improves gas transport efficiency, and ensures stable transmission of compression pressure at each stage, avoiding pressure loss caused by complex pipelines.

[0052] In an exemplary embodiment of this utility model, the connection between the fourth module and the left and right booster cylinder modules is provided with a screw and a washer. The washer includes an elastic washer, a flat washer, and an anti-loosening washer. The elastic washer is coaxially arranged with the corresponding end cap sealing assembly and is used to fill the end cap gap to improve sealing performance. The flat washer is used to protect the end cap surface from wear by the screw head. The anti-loosening washer is used to prevent the screw from loosening and maintain connection stability.

[0053] The modular design offers strong scalability, enabling multi-stage compression by increasing the number of booster cylinder modules without requiring redesign of the hydraulic cylinder modules, thus reducing equipment upgrade costs. It can also adapt to scenarios with larger displacement or higher pressure, expanding the applicable scenarios from a single type to multiple types, and solving the shortcomings of related technologies that cannot be expanded and require the replacement of the entire equipment for upgrades.

[0054] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the present invention. Attached Figure Description

[0055] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments conforming to the present invention and, together with the description, serve to explain the principles of the present invention. It is obvious that the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0056] Figure 1 A schematic diagram of the assembly structure of the dual-cylinder single-stage compressor provided in Embodiment 1 of this utility model;

[0057] Figure 2 A schematic diagram showing the disassembled structure of the dual-cylinder single-stage compressor provided in Embodiment 1 of this utility model;

[0058] Figure 3 A schematic diagram of the assembly structure of the dual-cylinder single-stage compressor provided in Embodiment 2 of this utility model;

[0059] Figure 4 A schematic diagram showing the disassembled structure of the dual-cylinder single-stage compressor provided in Embodiment 2 of this utility model;

[0060] Figure 5 This is a schematic diagram of the assembly structure of the single-cylinder two-stage compressor provided in Embodiment 3 of this utility model;

[0061] Figure 6 This is a schematic diagram of the disassembled structure of a single-cylinder two-stage compressor provided in Embodiment 3 of this utility model;

[0062] Figure 7 This is a schematic diagram of the maintenance module application structure provided in Embodiment 4 of this utility model;

[0063] Figure 8 This is a schematic diagram of the assembly structure of the dual-cylinder, two-stage compressor provided in Embodiment 5 of this utility model;

[0064] Figure 9 A schematic diagram showing the disassembled structure of the dual-cylinder, two-stage compressor provided in Embodiment 5 of this utility model;

[0065] Figure 10 This is a schematic diagram of the assembly structure of the dual-cylinder, two-stage compressor provided in Embodiment 6 of this utility model;

[0066] Figure 11 A schematic diagram showing the disassembled structure of the dual-cylinder, two-stage compressor provided in Embodiment 6 of this utility model;

[0067] Figure 12 A schematic diagram of the assembly structure of the single-cylinder four-stage compressor provided in Embodiment 7 of this utility model;

[0068] Figure 13 A schematic diagram showing the disassembled structure of the single-cylinder four-stage compressor provided in Embodiment 7 of this utility model;

[0069] Figure 14 This is a schematic diagram of the application structure of the maintenance module provided in Embodiment 8 of this utility model.

[0070] Explanation of reference numerals in the attached figures:

[0071] 1-First module; 101-Outer end cap; 102-D1 outer end cap; 103-D1 booster cylinder body; 104-D1 water jacket; 105-D1 piston sealing assembly; 106-D1 booster cylinder piston; 107-D1 inner end cap; 108-D1 inner end cap sealing assembly;

[0072] 2-Second Module; 201-Hydraulic Inner End Cap Sealing Assembly; 202-Hydraulic Inner End Cap; 203-Hydraulic Cylinder Body; 204-Piston Rod; 205-Hydraulic Cylinder Piston Sealing Assembly; 206-Hydraulic Cylinder Piston;

[0073] 3-Third Module; 301-Outer End Cap; 302-D2 Outer End Cap; 303-D2 Booster Cylinder Body; 304-D2 Water Jacket; 305-D2 Piston Sealing Assembly; 306-D2 Booster Cylinder Piston; 307-D2 Inner End Cap; 308-D2 Inner End Cap Sealing Assembly;

[0074] 4-The fourth module;

[0075] 5 - Fifth Module; 108 - D1 Inner End Cap Sealing Assembly; 107 - D1 Inner End Cap; 103 - D1 Booster Cylinder Body; 104 - D1 Water Jacket; 105 - D1 Piston Seal; 106 - D1 Booster Cylinder Piston; 501 - D1-D2 Inter-End Cap Seal; 502 - D1-D2 Inter-End Cap; 503 - Booster Piston Rod; 303 - D2 Booster Cylinder Body; 305 - D2 Piston Sealing Assembly; 304 - D2 Water Jacket; 306 - D2 Booster Cylinder Piston; 504 - D2 Outer End Cap;

[0076] 6-Sixth Module; 601-D3 Inner End Cap Sealing Assembly; 602-D3 Inner End Cap; 603-D3 Booster Cylinder Body; 604-D3 Water Jacket; 605-D3 Piston Seal; 606-D3 Booster Cylinder Piston; 607-D3-D4 Inter-End Cap Seal; 608-D3-D4 Inter-End Cap; 609-Booster Piston Rod; 610-D4 Booster Cylinder Body; 611-D4 Piston Sealing Assembly; 612-D4 Water Jacket; 613-D4 Booster Cylinder Piston; 614-D4 Outer End Cap. Detailed Implementation

[0077] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted. Furthermore, the drawings are merely illustrative of the present invention and are not necessarily drawn to scale.

[0078] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples in the accompanying drawings. It is understood that if the device of the icon is flipped so that it is upside down, the component described as "upper" will become the component described as "lower." When a structure is "upper" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0079] The terms “a,” “one,” “the,” and “at least one” are used to indicate the existence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first” and “second” are used only as markers and are not a limitation on the number of objects.

[0080] Example 1: Dual-cylinder single-stage compressor (Module 1 + Module 2)

[0081] like Figure 1-2 As shown, the compressor in this embodiment adopts a combination of "second module 2 (hydraulic cylinder module) + two first modules 1 (D1 booster cylinder modules)", and the assembly steps are as follows:

[0082] like Figure 2 As shown, the second module 2 is pre-assembled:

[0083] S1. Take the hydraulic cylinder body 203 and install the hydraulic cylinder piston sealing assembly 205 into the groove of the hydraulic cylinder piston 206.

[0084] S2. Insert the hydraulic cylinder piston 206 into the inner cavity of the hydraulic cylinder body 203, ensuring that the hydraulic cylinder piston sealing assembly 205 fits against the inner wall of the hydraulic cylinder body 203.

[0085] S3. Install the hydraulic inner end cap sealing assembly 201 at the stop on the left side of the hydraulic cylinder body 203, then install the hydraulic inner end cap 202 and tighten it with screws.

[0086] S4. Repeat step S3 to complete the installation of the hydraulic inner end cap 202 and the hydraulic inner end cap sealing assembly 201 on the right side of the hydraulic cylinder body 203.

[0087] S5. Connect and fix the inner side of the piston rod 204 to the hydraulic cylinder piston 206 to ensure that the piston rod 204 and the hydraulic cylinder piston 206 are coaxial, and complete the pre-assembly of the second module 2.

[0088] Continue as Figure 2 As shown, the first module 1 is pre-assembled:

[0089] S1. Take the D1 booster cylinder body 103 and install the D1 piston sealing assembly 105 into the groove of the D1 booster cylinder piston 106.

[0090] S2. Insert the piston 106 of the D1 booster cylinder into the inner cavity of the D1 booster cylinder body 103, ensuring that the D1 piston sealing assembly 105 fits against the inner wall of the D1 booster cylinder body 103.

[0091] S3. Install the D1 inner end cover sealing assembly 108 at the stop inside the D1 booster cylinder body 103, then install the D1 inner end cover 107 and tighten it with screws.

[0092] S4. Cover the outside of the D1 water jacket 104 with the outside of the D1 booster cylinder body 103, ensuring that the D1 water jacket 104 fits snugly against the D1 booster cylinder body 103, and fix it with screws.

[0093] S5. Install the outer end cover 102 of D1 at the stop on the outside of the D1 booster cylinder 103, and install a control valve in the air intake / exhaust passage of the outer end cover 102 of D1, and fasten it with a screw.

[0094] S6. Install the outer end cover 101 and fasten it with screws to complete the assembly of a first module 1;

[0095] S7. Repeat steps S1-S6 to assemble the second first module 1, ensuring that the structure and size of the two first modules 1 are consistent.

[0096] Continue as Figure 2 As shown, the overall assembly and positioning of the first module 1 and the second module 2:

[0097] S1. Place the second module 2 on the assembly platform and adjust it to a horizontal position;

[0098] S2. Insert a positioning pin into the positioning pin hole of the hydraulic inner end cover 202 on the left side of the second module 2.

[0099] S3. Fit the inner end cover 107 of the first module 1 on the left side with the hydraulic inner end cover 202 of the second module 2, and ensure that the positioning pin is inserted into the positioning pin hole of the inner end cover 107 of the D1 to achieve coaxial positioning.

[0100] S4. Pass the screw through the connecting hole between the first module 1 and the second module 2 on the left side, and tighten the screw in a diagonal sequence. At the same time, observe the wax mark on the screw to ensure that the deformation of the wax mark meets the tightening torque requirements.

[0101] S5. Install the elastic washer, flat washer and anti-loosening washer in sequence on the outside of the screw to complete the connection of the left module;

[0102] S6. Repeat steps S2-S5 to complete the connection between the first module 1 and the second module 2 on the right.

[0103] S7. Connect the cooling water pipeline: Connect the pipeline of the external cooling system to the inlet and outlet of the D1 water jacket 104 to ensure that the pipeline is sealed and leak-free.

[0104] S8. Connect the hydraulic lines: Connect the inlet and return oil pipes of the external hydraulic system to the hydraulic left chamber interface and hydraulic right chamber interface of the hydraulic cylinder body 203 respectively to complete the overall assembly.

[0105] The following is in conjunction with the appendix Figure 1 The working process of the compressor in this embodiment will be described as follows:

[0106] like Figure 1 As shown, the working process of this embodiment is based on the reciprocating motion of the hydraulic cylinder piston to achieve continuous gas compression, as detailed below:

[0107] The hydraulic cylinder piston moves to the left during the following phase:

[0108] a. The external hydraulic system supplies oil to the right hydraulic chamber of the hydraulic cylinder 203, while the left hydraulic chamber returns oil.

[0109] b. The hydraulic cylinder piston 206 moves linearly to the left under the action of the oil pressure difference, which drives the piston rod 204 to move to the left in sync.

[0110] c. Left first module 1: Piston rod 204 drives piston 106 of D1 booster cylinder to move to the left, which reduces the volume of working chamber of D1 booster cylinder on the left side. The gas in working chamber of D1 booster cylinder is compressed and the pressure increases. When the pressure reaches the set value, the gas is discharged from the gas outlet channel of D1 outer end cover 102 of D1 booster cylinder on the left side, thus completing the boosting.

[0111] d. Right side first module 1: Piston rod 204 drives piston 106 of D1 booster cylinder to move to the left, which increases the working chamber volume of right side D1 booster cylinder, reduces the pressure in the working chamber, and the gas is drawn into the working chamber from the air intake channel of D1 outer end cover 102, completing the air intake.

[0112] e. The cooling system works synchronously: Cooling water is introduced into the D1 water jacket 104 of the first module 1 on the left to remove the heat generated by the compression of the left D1 booster cylinder 103. At the same time, the cooling water in the end cover water tank cools the sealing components to ensure that the working temperature of the seals is stable.

[0113] The hydraulic cylinder piston moves to the right:

[0114] a. External hydraulic system switches oil flow direction: oil enters the left hydraulic chamber of hydraulic cylinder 203, while oil returns from the right hydraulic chamber at the same time;

[0115] b. The hydraulic cylinder piston 206 moves linearly to the right, causing the piston rod 204 to move synchronously to the right;

[0116] c. Left first module 1: D1 booster cylinder piston 106 moves to the right with piston rod 204, which increases the volume of the working chamber of left D1 booster cylinder, reduces the pressure in the working chamber, and the gas is drawn into the working chamber from the air intake channel of D1 outer end cover 102 to complete the air intake.

[0117] d. Right side first module 1: D1 booster cylinder piston 106 moves to the right with piston rod 204, causing the working chamber volume of the right side D1 booster cylinder to decrease, the gas in the chamber is compressed, and the pressure increases. When the pressure reaches the set value, the gas is discharged from the gas outlet channel of the D1 outer end cover 102 of the left side D1 booster cylinder, completing the boosting.

[0118] e. The cooling system works synchronously: Cooling water is introduced into the D1 water jacket 104 of the first module 1 on the right side to remove the heat generated by the compression of the D1 booster cylinder 103 on the right side. At the same time, the cooling water in the end cover water tank cools the sealing components to ensure that the working temperature of the seals is stable.

[0119] The compressor maintenance process in this embodiment is as follows:

[0120] If the piston sealing assembly 105 of the first module 1 on the right side leaks after the compressor has been running for a period of time, the seal needs to be replaced. The maintenance procedure is as follows:

[0121] a. Shut down the external hydraulic system and stop supplying oil to the hydraulic cylinder 203;

[0122] b. Open the pressure relief valve of the outer end cover 102 of the first module 1D1 on the right to release the gas in the working chamber and the isolation chamber to normal pressure;

[0123] c. Shut down the cooling system and disconnect the cooling water pipe from the hydraulic pipe;

[0124] d. Use tools to disassemble the connecting screw between the first module 1 and the second module 2 on the right side, and remove the screw and the matching washer;

[0125] e. Hold the outer end cover 101 of the right first module 1 and pull it outward along the axis to remove the entire right first module 1 (the second module 2 remains intact and no parts need to be disassembled).

[0126] f. Disassemble the first module 1 on the right: Sequentially disassemble the outer end cover 101, the outer end cover 102 of D1, the water jacket 104 of D1, the booster cylinder body 103 of D1, and the booster cylinder piston 106 of D1.

[0127] g. Remove the old D1 piston seal assembly 105 and install the new D1 piston seal assembly 105;

[0128] h. Reinstall the first module 1 on the right side in the following order: D1 booster cylinder piston 106, D1 booster cylinder body 103, D1 water jacket 104, D1 outer end cover 102, and outer end cover 101.

[0129] i. Position the reinstalled right-side first module 1 coaxially with the second module 2 using the positioning shoulder, tighten the screw and ensure that the tightening torque meets the standard;

[0130] j. Reconnect the cooling water pipes and hydraulic pipes to complete the maintenance.

[0131] Example 2: Dual-cylinder single-stage compressor (third module 3 + second module 2);

[0132] like Figure 3-4As shown, the difference between this embodiment and embodiment 1 is that the two first modules 1 are replaced with two third modules 3, and the assembly steps are as follows:

[0133] S1. Pre-assembly of Module 3: The structure is symmetrical to Module 1, except that the cylinder body size is different from Module 1. The assembly steps are the same as those of Module 1. Install the outer end cap 301, D2 outer end cap 302, D2 water jacket 304, D2 booster cylinder body 303, D2 booster cylinder piston 306, D2 piston sealing assembly 305, D2 inner end cap 307, and D2 inner end cap sealing assembly 308 in sequence, ensuring that the D2 water jacket 304 fits snugly against the D2 booster cylinder body 303, and that the air inlet / outlet channels and control valves of the D2 outer end cap 302 are installed in place.

[0134] S2. Overall assembly: The overall assembly steps are the same as in Example 1. The third module 3 and the second module 2 are coaxially positioned by the positioning shoulder, and fastened with screws. The cooling water pipeline and the hydraulic pipeline are connected to ensure that the equipment moves smoothly and is sealed without leakage after assembly.

[0135] Because the inner diameter of the D2 booster cylinder 303 is different from that of the D1 booster cylinder 103, the displacement of this embodiment differs from that of embodiment 1. It can meet the needs of larger displacement gas preparation, and there is no need to replace the hydraulic cylinder module. The parameters can be adjusted simply by replacing the booster cylinder module.

[0136] The working process and maintenance procedure of this embodiment are the same as those of Embodiment 1.

[0137] Compared to the fixed three-stage compression structure of related technologies, this embodiment can achieve displacement adjustment by replacing the booster cylinder module without replacing the entire compressor, adapting to the needs of large displacement scenarios and significantly reducing equipment investment costs; at the same time, the D2 water jacket 304 can effectively remove the heat generated during the large displacement compression process, ensuring stable cylinder temperature and avoiding cylinder overheating problems caused by increased displacement.

[0138] Example 3: Single-cylinder two-stage compressor (Module 1 + Module 2 + Module 3)

[0139] The single-cylinder two-stage compressor in this embodiment can be adapted to testing scenarios with higher pressures (such as 70-90MPa); Figure 5-6 As shown, this embodiment uses a combination of "left first module 1 + second module 2 + right third module 3, where the inner diameter d1 of the left first module 1 is greater than the inner diameter d2 of the right third module 3" to form a two-stage compression. The working principle is as follows:

[0140] First stage compression (piston rod moves to the left):

[0141] The hydraulic cylinder piston 206 drives the piston rod 204, which in turn drives the D1 booster cylinder piston 106 to move to the left. The volume of the working chamber of the left D1 booster cylinder decreases, so that the compressed gas is transported from the working chamber of the D1 booster cylinder through the intermediate pipeline and is drawn into the working chamber of the D2 booster cylinder, so that the gas is compressed to the interstage pressure.

[0142] Second, the first stage of intake and the second stage of compression (piston rod moves to the right).

[0143] The hydraulic cylinder piston 206 drives the piston rod 204, which in turn drives the D2 booster cylinder piston 306 to move to the right. The working chamber of the right-side D3 booster cylinder decreases. After the gas after the first stage of compression enters the working chamber of the right-side third module 3, the gas is further compressed to a higher pressure. The gas compressed to a higher pressure is discharged from the exhaust channel of the outer end cover 302 of D2 and supplied to external equipment.

[0144] At the same time, the working chamber of the D1 booster cylinder in the first module 1 on the left draws in gas from the air intake channel of the outer end cover of D1, completing the first stage of air intake.

[0145] In addition, the compressor in this embodiment can also achieve sealed cooling synergy: the water channels of the two end caps are connected in series, and the cooling water enters from the inlet of the left D1 inner end cap 107, flows through the D1 inner end cap sealing assembly 108, the hydraulic inner end cap sealing assembly 201, and the D2 inner end cap sealing assembly 308 in sequence, and finally exits from the outlet of the right D2 inner end cap 307, ensuring that all sealing assemblies are effectively cooled.

[0146] Related technologies require three cylinders to achieve higher pressure output (three-stage compression), while this embodiment only requires two booster cylinder modules (two-stage compression). The number of cylinders is reduced, the equipment structure is more compact, and it occupies less installation space. If the output pressure needs to be adjusted, only the booster cylinder module on the left or right side needs to be replaced, without adjusting the entire compression structure. This flexibility is far superior to the fixed three-stage compression design of related technologies.

[0147] Example 4: Maintenance Module Application (Module 4 + Module 1, adapted to peak maintenance scenarios at hydrogen refueling stations)

[0148] like Figure 7 As shown, this embodiment is based on the structure of embodiment 1, and integrates "second module 2 + inner end caps 107 on both sides D1" into fourth module 4. The assembly steps are as follows:

[0149] S1. Complete the pre-assembly of the second module 2 according to the steps of Example 1;

[0150] S2. On the outside of the hydraulic inner end cover 202 on the left side of the second module 2, the D1 inner end cover 107 is positioned coaxially with the D1 inner end cover 107 by the positioning shoulder. The D1 inner end cover sealing assembly 108 is installed and tightened with screws to ensure that the D1 inner end cover 107 and the hydraulic inner end cover 202 fit together without gaps.

[0151] S3. Repeat step S2 to complete the installation of the inner end cap 107 on the right side D1 and complete the assembly of the fourth module 4.

[0152] The following describes the maintenance process for the compressor in this embodiment:

[0153] If the D1 piston sealing assembly 105 of the first module 1 on the right side suddenly leaks, emergency maintenance is required. The procedure is as follows:

[0154] S1. Shut down the hydraulic system and open the pressure relief valve to reduce the pressure inside the chamber of the first module 1 on the right to normal pressure;

[0155] S2. Disassemble the first module 1 on the right: Quickly disassemble the connecting screw between the fourth module 4 and the first module 1 on the right, and remove the first module 1 on the right (keep the fourth module 4 intact, and do not disconnect the hydraulic line).

[0156] S3. Replace the seal: Disassemble the first module 1 on the right, replace the D1 piston seal assembly 105, quickly reinstall the first module 1, and complete the maintenance.

[0157] Example 5: Dual-cylinder, two-stage compressor (Module 5 + Module 2, adapted for high-displacement scenarios in large hydrogen refueling stations)

[0158] The compressor in this embodiment is used for hydrogen boosting in large hydrogen refueling stations (requirements: two-stage compression to increase pressure, large displacement to meet the hydrogen refueling needs of multiple vehicles). It adopts a five-cylinder coaxial series structure of "second module 2 (hydraulic cylinder module) + two fifth modules 5 (D1+D2 booster cylinder modules, d1>d2)". The assembly steps, working process and maintenance procedures are as follows:

[0159] First, module pre-assembly

[0160] 1. Pre-assembly of Module 2 (Hydraulic Cylinder Module)

[0161] S1. Take the hydraulic cylinder body 204 and embed the hydraulic cylinder piston sealing assembly 206 into the groove of the hydraulic cylinder piston 205, ensuring that the sealing assembly fits snugly against the inner wall of the groove without gaps.

[0162] S2. Slowly insert the hydraulic cylinder piston 205 with the sealing assembly assembled into the inner cavity of the hydraulic cylinder body 204.

[0163] S3. Place the hydraulic inner end cap sealing assembly 203 at the left stop of the hydraulic cylinder body 204, align the mounting hole and install the hydraulic inner end cap 202, and gradually tighten it to the preset state with the screw.

[0164] S4. Repeat step S3 to complete the installation of the hydraulic inner end cap 202 on the right side of the hydraulic cylinder body 204 and the hydraulic inner end cap sealing assembly 203.

[0165] S5. Connect and fix the inner side of the piston rod 201 to the hydraulic cylinder piston 205 through the adapter structure to ensure that the piston rod axis coincides with the piston axis. Push the piston rod to verify the overall movement performance and complete the pre-assembly of the second module 2.

[0166] 2. Pre-assembly of Module 5 (D1+D2 booster cylinder module)

[0167] S1. Take D1 booster cylinder body 103, install D1 piston seal 105 into the sealing groove of D1 booster cylinder piston 106, and install the piston into the inner cavity of D1 booster cylinder body 103.

[0168] S2. Install the D1 inner end cap sealing assembly 108 at the inner stop of the D1 booster cylinder body 103, insert the D1 inner end cap 107, and tighten it with screws to ensure that the end cap fits tightly with the cylinder body.

[0169] S3. Cover the outside of the D1 water jacket 104 with the outside of the D1 booster cylinder 103, align the mounting holes of the water jacket and the cylinder, and fix it with screws to ensure that the inner side of the water jacket fits against the outer wall of the cylinder and that the cooling water flow channel is not blocked.

[0170] S4. Take the D2 booster cylinder body 303, install the D2 piston sealing assembly 305 into the sealing groove of the D2 booster cylinder piston 306, install the piston into the inner cavity of the D2 booster cylinder body 303, and check the movement performance.

[0171] S5. Between the outer side of the D1 booster cylinder body 103 and the inner side of the D2 booster cylinder body 303, install the D1D2 inter-end cover seal 501 and the D1D2 inter-end cover 502 in sequence, and tighten them with screws to ensure that the gas passage on the end cover is aligned with the D1 working chamber and the D2 working chamber.

[0172] S6. Connect one end of the booster piston rod 503 to the piston 106 of the booster cylinder D1, and the other end to the piston 306 of the booster cylinder D2. Adjust the coaxiality to ensure that the two pistons move synchronously.

[0173] S7. Cover the outside of the D2 water jacket 304 with the outside of the D2 booster cylinder body 303 and fix it with screws; install the D2 outer end cover 504 on the outside of the D2 booster cylinder body 303, install control valves in the air inlet and outlet channels of the end cover, and tighten them with screws.

[0174] S8. Repeat steps S1-S7 to assemble the second fifth module 5, ensuring that the structure and size of the two modules are completely consistent, and complete the pre-assembly of the fifth module 5.

[0175] 3. Overall assembly and positioning

[0176] S1. Place the second module 2 on the horizontal assembly platform;

[0177] S2. By using the positioning shoulder, the D1 inner end cover 107 of the fifth module 5 on the left side is attached to the hydraulic inner end cover 202 to achieve coaxial positioning between modules.

[0178] S3. Pass the screw through the connection hole between the fifth module 5 on the left and the second module 2;

[0179] S4. Install the elastic washer, flat washer, and anti-loosening washer in sequence on the outside of the screw to complete the connection of the left module;

[0180] S5. Repeat steps S2-S4 to complete the connection between the fifth module 5 on the right and the second module 2.

[0181] S6. Connect the cooling water pipes: Connect the water outlet pipes of the external cooling system to the inlets of the D1 water jacket 104 and D2 water jacket 304 of the fifth module 5 on both sides respectively. Connect the inlet pipes to the corresponding water jacket outlets. Pass in a small amount of cooling water to check the pipe sealing and ensure there is no leakage.

[0182] S7. Connect the hydraulic lines: Connect the inlet and return oil pipes of the external hydraulic system to the hydraulic left and right chamber interfaces of the hydraulic cylinder body 204 respectively to complete the overall assembly.

[0183] Working process (twin-cylinder two-stage compression):

[0184] 1. Hydraulic cylinder piston moving to the right stage

[0185] a. The external hydraulic system supplies oil to the left hydraulic chamber of hydraulic cylinder 204 and returns oil to the right hydraulic chamber.

[0186] b. The hydraulic cylinder piston 205 moves linearly to the right under the action of the oil pressure difference, which drives the piston rods 201 on both sides to move to the right synchronously.

[0187] c. Right Fifth Module 5: The piston rod drives the piston 106 of the D1 booster cylinder to move to the right - the volume of the D1 working chamber decreases, and the raw material gas is boosted by the first stage; the gas after the first stage of boosting enters the D2 working chamber through the gas channel of the D1D2 end cover 502, and at the same time, the piston 306 of the D2 booster cylinder moves to the right - the volume of the D2 working chamber decreases, and the gas is boosted by the second stage. Finally, the high-pressure gas is discharged from the gas outlet channel of the D2 outer end cover 504 to the hydrogen storage tank of the hydrogen refueling station.

[0188] d. Left fifth module 5: The piston rod drives the piston 106 of the D1 booster cylinder to move to the right - the volume of the D1 working chamber increases, and the raw material gas is drawn into the D1 working chamber from the air inlet channel of the D2 outer end cover 504 for the first stage of intake; at the same time, the piston 306 of the D2 booster cylinder moves to the right - the volume of the D2 working chamber increases, reserving space for receiving the gas after the first stage of boosting (preparation for the second stage of intake).

[0189] e. Synchronous operation of the cooling system: Cooling water circulates in the D1 water jacket 104, D2 water jacket 304 and end cover water channel, carrying away the heat from the cylinder block and sealing components.

[0190] 2. The hydraulic cylinder piston moves to the left during this phase.

[0191] a. External hydraulic system switches oil flow direction: oil enters the right hydraulic chamber of hydraulic cylinder 204, and oil returns to the left hydraulic chamber;

[0192] b. The hydraulic cylinder piston 205 moves linearly to the left, causing the piston rods 201 on both sides to move synchronously to the left.

[0193] c. Left fifth module 5: D1 booster cylinder piston 106 moves to the left - D1 working chamber volume decreases (first stage boosting), D2 booster cylinder piston 306 moves to the left - A2 chamber volume decreases (second stage boosting), high pressure gas is discharged from the D2 outer end cover 504 gas outlet channel;

[0194] d. Right fifth module 5: D1 booster cylinder piston 106 moves to the left - D1 working chamber volume increases (first stage intake); D2 booster cylinder piston 306 moves to the left - A2 chamber volume increases (second stage intake);

[0195] e. Repeat the "right-left movement" cycle to achieve continuous two-stage compression of hydrogen.

[0196] 3. Maintenance procedure (replacing the D2 piston seal assembly 305)

[0197] a. Shut down and release pressure;

[0198] b. Disconnect the pipeline: Turn off the cooling system and disconnect the cooling water pipeline from the hydraulic pipeline;

[0199] c. Disassemble the booster cylinder module: Use tools to remove the connecting screw between the fifth module 5 on the right and the second module 2, and remove the screw and washer; hold the outer end cap 504 of the D2 of the fifth module 5 on the right and pull it outward along the axis to remove the entire fifth module 5 on the right (the second module 2 remains intact);

[0200] d. Replace the seals: Disassemble the fifth module 5 on the right side, and in sequence remove the outer end cover 504 of D2, the water jacket 304 of D2, the booster cylinder body 303 of D2, and the piston of D2 booster cylinder 306; remove the old piston sealing assembly 305 of D2 and install the new sealing assembly.

[0201] e. Reinstall the module: Reinstall the fifth module 5 in the following order: "D2 booster cylinder piston 306-D2 booster cylinder body 303-D2 water jacket 304-D2 outer end cover 504-D1D2 intermediate end cover 502-D1 booster cylinder body 103-D1 water jacket 104-D1 inner end cover 107".

[0202] Example 6: Dual-cylinder, two-stage compressor (Module 6 + Module 2)

[0203] like Figure 2 , Figure 3 As shown, the difference between this embodiment and embodiment 5 is that "the two fifth modules 5 are replaced with two sixth modules 6 (D3+D4 booster cylinder modules, d3>d4)", as detailed below:

[0204] First, module assembly:

[0205] 1. Pre-assembly of Module 6 (D3+D4 booster cylinder module):

[0206] S1. Take the D3 booster cylinder body (603), install the D3 piston seal (605) into the groove of the D3 booster cylinder piston (606), install it into the cylinder body and check its movement performance;

[0207] S2. Install the D3 inner end cap sealing assembly (601), D3 inner end cap (602), and D3 water jacket (604) in sequence, and tighten them with screws;

[0208] S3. Take the D4 booster cylinder body (610), install the D4 piston sealing assembly (611) and the D4 booster cylinder piston (613), connect the D3 booster cylinder body (603) through the D3D4 inter-end cover seal (607) and the D3D4 inter-end cover (608), and install the booster piston rod (609).

[0209] S4. Install the D4 water jacket (612), D4 outer end cap (614) and control valve to complete the assembly of one sixth module 6; repeat the assembly of the second sixth module 6.

[0210] 2. Overall assembly:

[0211] The overall assembly steps are consistent with those in Example 5. Coaxial positioning is achieved by using the positioning shoulder, the screw is tightened and the sealing is verified, and the cooling and hydraulic lines are connected.

[0212] Beneficial effects:

[0213] Because the inner diameters of d3 and d4 are different from those of d1 and d2 (d3>d1, d4>d2), the displacement of this embodiment is larger than that of embodiment 5, which can meet the needs of large-displacement gas preparation. There is no need to replace the hydraulic cylinder module; the parameters can be adjusted simply by replacing the booster cylinder module, which reduces the equipment investment cost. At the same time, the D3 water jacket 604 and the D4 water jacket 612 can effectively remove the heat generated by large-displacement compression and maintain the stability of the cylinder.

[0214] Example 7: Single-cylinder four-stage compressor (Module 5 + Module 2 + Module 6, adapted for ultra-high pressure detection scenarios);

[0215] like Figure 3 As shown, this embodiment is used for ultra-high pressure gas detection (requirement: four-stage compression to achieve ultra-high pressure output). It adopts a five-cylinder coaxial series structure of "left fifth module 5 (D1+D2) + second module 2 + right sixth module 6 (D3+D4)" (d1>d3>d2>d4). The working process is as follows:

[0216] Working process (single-cylinder four-stage compression)

[0217] The hydraulic cylinder piston moves to the left during the first and third stages of pressurization.

[0218] a. Hydraulic right chamber inlet, hydraulic left chamber outlet - hydraulic cylinder piston 205 moves linearly to the left, driving piston rod 201 to move synchronously to the left;

[0219] b. The piston 106 of the D1 booster cylinder in the fifth module 5 moves to the left - the volume of the D1 working chamber decreases (first-stage boosting), and the gas enters the D3 working chamber through the independent gas channel between the fifth module 5 and the sixth module 6 to achieve first-stage boosting;

[0220] c. The piston 306 of the D2 booster cylinder in the fifth module 5 moves to the left - the volume of the D2 working chamber decreases (three-stage boosting), and the gas enters the D4 working chamber through the independent gas channel between the fifth module 5 and the sixth module 6 to achieve three-stage boosting.

[0221] The hydraulic cylinder piston moves to the right during the second and fourth stages of pressurization.

[0222] a. Hydraulic left chamber inlet oil, hydraulic right chamber outlet oil - hydraulic cylinder piston 205 moves linearly to the right, driving piston rod 201 to move synchronously to the right;

[0223] b. The piston 106 of the D1 booster cylinder in the fifth module 5 on the left moves to the right - the volume of the D1 working chamber increases (raw material gas is drawn in);

[0224] c. The working chamber of the D3 booster cylinder in the right sixth module 6 decreases, and the medium enters the working chamber of the D2 booster cylinder in the left fifth module 5 from this chamber, realizing two-stage boosting;

[0225] d. The working chamber of the D4 booster cylinder in the sixth module 6 on the right is reduced, and the medium is pressurized in four stages from this chamber and discharged from the compressor;

[0226] e. Synchronous operation of the cooling system: Cooling water circulates in the end cover water tank and each water jacket to cool all sealing components and cylinder, ensuring equipment stability.

[0227] Beneficial effects:

[0228] Compared to traditional multi-stage compressors, this embodiment achieves four-stage compression through modular combination, eliminating the need for multiple devices connected in series, resulting in a smaller equipment footprint; furthermore, the pressure ratio of each stage can be adjusted by replacing modules to adapt to different detection pressure requirements, offering greater flexibility.

[0229] Example 8: Application of the maintenance module (Module 4 + booster cylinder module, adapted to peak maintenance scenarios of hydrogen refueling stations)

[0230] like Figure 4 As shown, this embodiment is based on the structure of embodiment 5, integrating "second module 2 + two sides D1 inner end caps 107" into the fourth module 4 (maintenance hydraulic cylinder module). The maintenance process is as follows:

[0231] Assembly of Modules 1 and 4

[0232] S1. Complete the pre-assembly of the second module 2 according to the steps in Example 5;

[0233] S2. On the outside of the hydraulic inner end cover 202 on the left side of the second module 2, connect the inner end cover 107 of D1 through the positioning shoulder, install the inner end cover sealing assembly 108 of D1 and fasten it with screws.

[0234] S3. Repeat step S2 to complete the installation of the inner end cap 107 on the right side D1, forming the fourth module 4 (the whole module has no disassembled parts).

[0235] Second, peak-hour maintenance (replacing piston seal 105 for D1).

[0236] a. Quick shutdown;

[0237] b. Disassembling the module: Only disconnect the connecting screw between the fourth module 4 and the fifth module 5 on the left, and remove the fifth module 5 on the left.

[0238] c. Replace the seal: Disassemble module 5, replace piston seal 105 with D1 and reinstall it;

[0239] d. Reset and run;

[0240] The total maintenance time is much shorter than that of traditional structures, allowing for rapid service restoration during peak hours at hydrogen refueling stations and reducing operational losses.

[0241] Other embodiments of the present invention will readily occur to those skilled in the art upon consideration of the specification and practice of the embodiments thereof. The present invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not covered by the invention. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the appended claims.

Claims

1. A hydraulically driven piston compressor with a hydraulic cylinder in the middle, characterized in that, The main body is a multi-cylinder coaxial series structure with a hydraulic cylinder module in the middle. A left booster cylinder module is located on the left side of the hydraulic cylinder module, and a right booster cylinder module is located on the right side. The hydraulic cylinder module, the left booster cylinder module, and the right booster cylinder module are independent and detachable structures. The modules are connected by flanges and screws. There is no long tie rod running through all cylinders, so the booster cylinder module can be replaced or maintained individually without disassembling all cylinders.

2. The hydraulically driven piston compressor with a hydraulic cylinder in the middle according to claim 1, characterized in that, The main body is a three-cylinder coaxial series structure, and the left booster cylinder module and the right booster cylinder module are both modules containing one booster cylinder; The hydraulic cylinder module is defined as the second module, and the left booster cylinder module and the right booster cylinder module are selected as either the first module or the third module; The second module includes a hydraulic inner end cap sealing assembly (201), a hydraulic inner end cap (202), a hydraulic cylinder body (203), a piston rod (204), a hydraulic cylinder piston sealing assembly (205), and a hydraulic cylinder piston (206). The hydraulic cylinder piston (206) divides the inner cavity of the hydraulic cylinder body (203) into a hydraulic left cavity and a hydraulic right cavity. The inner side of the piston rods (204) on both sides of the hydraulic cylinder piston (206) is connected to the hydraulic cylinder piston (206), and the outer side is in contact with the booster cylinder pistons in the left and right booster cylinder modules, respectively, so that the hydraulic cylinder piston (206), the left booster cylinder piston, the right booster cylinder piston, and the two piston rods (204) move synchronously left and right in a straight line. The first module includes an outer end cap, a D1 outer end cap (102), a D1 booster cylinder body (103), a D1 piston sealing assembly, a D1 booster cylinder piston, a D1 inner end cap (107), and a D1 inner end cap sealing assembly (108). The third module includes an outer end cap, a D2 outer end cap, a D2 booster cylinder body, a D2 piston sealing assembly (305), a D2 booster cylinder piston, a D2 inner end cap (307), and a D2 inner end cap sealing assembly (308). The D1 booster cylinder body (103) and the D2 booster cylinder body (103) have different inner diameters. By changing the type of the left and right booster cylinder modules, a dual-cylinder single-stage compression mode or a single-cylinder two-stage compression mode can be selectively implemented. The dual-cylinder single-stage compression mode is in which both the left and right booster cylinder modules are either the first module or both are the third module. The single-cylinder two-stage compression mode is in which one of the left and right booster cylinder modules is the first module and the other is the third module.

3. The hydraulically driven piston compressor with the hydraulic cylinder in the middle according to claim 2, characterized in that: The first module further includes a D1 water jacket (104), and the third module further includes a D2 water jacket (304); the D1 water jacket (104) covers the outside of the D1 booster cylinder body (103), and the D2 water jacket (304) covers the outside of the D2 booster cylinder body; the inner sides of the D1 water jacket (104) and the D2 water jacket (304) are both in contact with the outer wall of the corresponding booster cylinder body, and the D1 water jacket (104) and the D2 water jacket (304) are both provided with cooling water channels.

4. The hydraulically driven piston compressor with the hydraulic cylinder in the middle according to claim 3, characterized in that: Water channels are provided on the side of the hydraulic inner end cap (202) and the side of the inner end cap (107) or the inner end cap (307) of D1. The water channels are arranged around the sealing assembly (201) of the inner hole of the end cap, and cooling water can be introduced into the water channels.

5. The hydraulically driven piston compressor with the hydraulic cylinder in the middle according to claim 4, characterized in that: The water channel of the hydraulic inner end cap (202) is connected to the water channel of the inner end cap (107) of D1 or the inner end cap (307) of D2 to form a continuous cooling water channel; the inlet of the continuous cooling water channel is located on the inner end cap (107) of D1 or the inner end cap (307) on one side, and the outlet is located on the inner end cap (107) of D1 or the inner end cap (307) on the other side.

6. The hydraulically driven piston compressor with the hydraulic cylinder in the middle according to claim 2, characterized in that, The piston of the D1 booster cylinder divides the inner cavity of the D1 booster cylinder body (103) into the outer D1 working cavity and the inner D1 isolation cavity; the piston of the D2 booster cylinder divides the inner cavity of the D2 booster cylinder body into the outer D2 working cavity and the inner D2 isolation cavity; the D1 isolation cavity and the D2 isolation cavity are used to isolate the compression medium of the corresponding working cavity from the hydraulic oil of the hydraulic cylinder module.

7. The hydraulically driven piston compressor with a hydraulic cylinder in the middle according to any one of claims 2-6, characterized in that: The hydraulic cylinder module is further modified by adding either an inner end cap (107) of D1 or an inner end cap (307) of D2 to one side to form a fourth module. The fourth module is a maintenance-specific module. When the seals of the left and right booster cylinder modules need to be replaced, the fourth module remains intact and is not disassembled. Only the booster cylinder module to be replaced is removed from the fourth module and disassembled.

8. The hydraulically driven piston compressor with a hydraulic cylinder in the middle according to any one of claims 2-6, characterized in that: When both sides of the second module are simultaneously the first module or the third module, when the hydraulic left chamber is filled with oil and the hydraulic right chamber is discharged with oil, the hydraulic cylinder piston (206) moves linearly to the right, driving the booster cylinder piston of the right booster cylinder module to move outward to reduce the working chamber volume and achieve pressure increase, while driving the booster cylinder piston of the left booster cylinder module to move inward to expand the working chamber volume and achieve air intake; when the hydraulic right chamber is filled with oil and the hydraulic left chamber is discharged with oil, the hydraulic cylinder piston (206) moves linearly to the left, driving the booster cylinder piston of the left booster cylinder module to move outward to reduce the working chamber volume and achieve pressure increase, while driving the booster cylinder piston of the right booster cylinder module to move inward to expand the working chamber volume and achieve air intake; When the left side of the second module is the first module and the right side is the third module, and the inner diameter d1 of the D1 booster cylinder body (103) of the first module is greater than the inner diameter d2 of the D2 booster cylinder body of the third module, when the hydraulic right chamber is filled with oil and the hydraulic left chamber is filled with oil, the hydraulic cylinder piston (206) moves to the left in a straight line, driving the booster cylinder piston of the left D1 booster cylinder module to move outward to reduce the working chamber volume, so that the compressed gas is transported from the working chamber of the D1 booster cylinder through the intermediate pipeline and sucked into the working chamber of the D2 booster cylinder of the right D2 booster cylinder module, so that the gas is compressed to the interstage pressure; when the hydraulic left chamber is filled with oil and the hydraulic right chamber is filled with oil, the hydraulic cylinder piston (206) moves to the right in a straight line, driving the D2 booster cylinder piston rod to move outward to reduce the working chamber volume, and the gas is further compressed to achieve secondary compression. At the same time, the left D1 booster cylinder piston moves inward to expand the working chamber of the D1 booster cylinder to achieve air intake.

9. The hydraulically driven piston compressor with a hydraulic cylinder in the middle according to claim 1, characterized in that, The main body is a five-cylinder coaxial series structure, and the left booster cylinder module and the right booster cylinder module are both modules containing two-stage booster cylinders; The hydraulic cylinder module is defined as the second module, and the left booster cylinder module and the right booster cylinder module are selected as either the fifth module or the sixth module; The second module includes a hydraulic inner end cap sealing assembly (201), a hydraulic inner end cap (202), a hydraulic cylinder body (203), a piston rod (204), a hydraulic cylinder piston sealing assembly (205), and a hydraulic cylinder piston (206). The hydraulic cylinder piston (206) divides the inner cavity of the hydraulic cylinder body (203) into a hydraulic left cavity and a hydraulic right cavity. The inner side of the piston rods (204) on both sides of the hydraulic cylinder piston (206) is connected to the hydraulic cylinder piston (206), and the outer side is in contact with the booster cylinder pistons in the left and right booster cylinder modules, respectively, so that the hydraulic cylinder piston (206), the left booster cylinder piston, the right booster cylinder piston, and the two piston rods (204) move synchronously left and right in a straight line. The fifth module includes a D1 inner end cap sealing assembly (108), a D1 inner end cap (107), a D1 booster cylinder body (103), a D1 water jacket (104), a D1 piston sealing assembly, a D1 booster cylinder piston, a D1D2 inter-end cap seal (501), a D1D2 inter-end cap (502), a booster piston rod, a D2 booster cylinder body, a D2 piston sealing assembly (305), a D2 water jacket (304), a D2 booster cylinder piston, and a D2 outer end cap. The inner diameter d1 of the D1 booster cylinder body (103) is greater than the inner diameter d2 of the D2 booster cylinder body. The sixth module includes a D3 inner end cap sealing assembly (601), a D3 inner end cap (602), a D3 booster cylinder body, a D3 water jacket (604), a D3 piston seal (605), a D3 booster cylinder piston (606), a D3-D4 inter-end cap seal (607), a D3-D4 inter-end cap (608), a booster piston rod, a D4 booster cylinder body, a D4 piston sealing assembly (611), a D4 water jacket (612), a D4 booster cylinder piston (613), and a D4 outer end cap (614). The inner diameter d3 of the D3 booster cylinder body is greater than the inner diameter d4 of the D4 booster cylinder body. By changing the type of the left and right booster cylinder modules, a dual-cylinder dual-stage compression mode or a single-cylinder four-stage compression mode can be selectively implemented. The dual-cylinder dual-stage compression mode is that both the left and right booster cylinder modules are either the fifth module or both are the sixth module. The single-cylinder four-stage compression mode is that the left booster cylinder module is the fifth module and the right booster cylinder module is the sixth module, d1>d3>d2>d4.

10. The hydraulically driven piston compressor with a hydraulic cylinder in the middle according to claim 9, characterized in that, The fifth module's D1 water jacket (104) covers the outside of the D1 booster cylinder body (103), and the D2 water jacket (304) covers the outside of the D2 booster cylinder body; the sixth module's D3 water jacket (604) covers the outside of the D3 booster cylinder body, and the D4 water jacket (612) covers the outside of the D4 booster cylinder body; the inner side of each water jacket is in contact with the outer wall of the corresponding booster cylinder body, and each water jacket is provided with a cooling water channel, through which cooling water can be introduced to cool the booster cylinder body.

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