A piston sealing mechanism for a piston-type high-pressure hydrogen compressor and a high-pressure hydrogen compressor

Abstract

The application discloses a piston sealing mechanism for a piston high-pressure hydrogen compressor and the high-pressure hydrogen compressor and belongs to the compressor field, which comprises a cylinder, a piston assembly movably connected to one end of the cylinder, and a gas valve installed at the other end of the cylinder, and a compression cavity is formed between the piston assembly and the gas valve; one side of the piston assembly close to the compression cavity is a high-pressure side, and the other side of the piston assembly away from the compression cavity is a low-pressure side; the piston assembly comprises a piston and a piston ring, a plurality of piston ring grooves are formed in the piston, and the piston ring comprises an airtight ring and a second cutout ring; the plurality of piston rings are fixed on the piston through the piston ring grooves and are arranged along the piston axis direction in sequence, and the airtight ring is arranged on the high-pressure side and the second cutout ring is arranged on the low-pressure side; a communication hole is arranged at the end of the piston close to the compression cavity, and the communication hole communicates the piston ring grooves connected by the plurality of airtight rings; and a supporting ring is arranged at the connection between the piston and the cylinder. The application can increase the service life of the piston ring while guaranteeing the sealing performance of hydrogen.

Description

Technical Field

[0001] The invention belongs to the field of compressors and relates to a piston sealing mechanism for a piston-type high-pressure hydrogen compressor and the high-pressure hydrogen compressor. Background Art

[0002] When filling a tank truck with hydrogen, a high-pressure hydrogen compressor is required to pressurize it. Since the diaphragm stroke of the diaphragm compressor is small, it cannot meet the large-flow hydrogen filling needs. Therefore, the development of a reciprocating hydrogen filling compressor is a key step in achieving large-scale hydrogen storage and transportation.

[0003] To prevent gas from escaping along the moving piston when the compressor piston is operating, the existing solution is to install multiple sealing piston rings on the piston, using the piston rings to abut against the inner wall of the cylinder to prevent gas leakage. However, the hydrogen used in high-pressure hydrogen compressors has a very small molecular weight and a higher diffusion coefficient than gases such as air. Under the same piston ring structure, hydrogen is more likely to leak than other large molecular gases. If a piston compressor is used to compress hydrogen, the piston ring seal must be oil-free lubricated. Since there is no continuous oil film between the contact surface of the oil-free piston ring and the cylinder to reduce wear, the wear coefficient is significantly higher and the service life is almost half that of the oil-lubricated piston ring. When oil-free lubricated piston rings are applied to higher operating pressures, they will quickly fail due to excessive wear rate. The design of the dynamic sealing mechanism of the hydrogen compressor piston ring must not only ensure the high sealing performance of the piston ring, but also consider the service life of the piston ring.

[0004] During operation, the piston rings are held tightly against the cylinder surface due to the pressure differential between the front (high-pressure side) and rear (low-pressure side) of the rings. The contact pressure between the piston rings and the cylinder wall is known as the specific pressure. However, in practice, the high sealing performance of the piston rings results in a delayed transmission of the pressure differential, resulting in uneven specific pressure distribution across the piston rings. Dynamic and static pressure differences cause the specific pressure to be concentrated on the first piston ring on the cover and shaft sides, respectively. This uneven specific pressure distribution has even more serious consequences for sealing high-pressure hydrogen. Under high-pressure, oil-free conditions, the frictional heat generated by the concentratedly loaded piston ring is far greater than that of the other rings. This frictional heat cannot be rapidly dissipated through the low thermal conductivity of the self-lubricating material, leading to rapid thermal failure of the piston ring.

[0005] Currently, the common method of improving the specific pressure distribution of piston ring packs is to change the gap between the piston ring cutouts. However, in high-pressure hydrogen environments, this method not only fails to effectively distribute the load evenly, but also leads to excessive leakage, failing to meet hydrogen sealing requirements. Therefore, it is necessary to propose a new piston ring pack sealing structure to achieve the goals of reducing hydrogen leakage and extending service life. Summary of the Invention

[0006] The piston sealing mechanism for the piston high-pressure hydrogen compressor and the high-pressure hydrogen compressor provided by the application ensure that hydrogen can be reliably sealed in the compression cavity under high pressure, minimize the possibility of leakage, effectively reduce the wear and stress of the piston ring during operation through multiple measures such as optimization of the material selection of the piston ring, improvement of the structural design of the piston ring, and reasonable planning of the working environment of the piston ring, and thus significantly increase the service life of the piston ring to overcome the shortcomings of the prior art.

[0007] To achieve the above object, the application provides the following technical solutions:

[0008] In one aspect, the application provides a piston sealing mechanism for a piston high-pressure hydrogen compressor, comprising a cylinder, the cylinder having a piston assembly movably connected inside one end and having a gas valve installed at the other end, a compression cavity being formed between the piston assembly and the gas valve; the side of the piston assembly close to the compression cavity being a high-pressure side, and the side of the piston assembly away from the compression cavity being a low-pressure side.

[0009] The piston assembly comprises a piston and a piston ring, the piston being provided with a plurality of piston ring grooves, and the piston ring comprising an airtight ring and a second cutout ring; the plurality of piston rings being fixed on the piston through the piston ring grooves and arranged in sequence along the piston axis direction, and the airtight ring being arranged at the high-pressure side and the second cutout ring being arranged at the low-pressure side.

[0010] The end of the piston close to the compression cavity is provided with a communication hole, the communication hole communicating the piston ring grooves connected by the airtight rings, the communication hole reducing the sealing pressure difference borne by the airtight rings close to the compression cavity, reducing the pressure and friction force borne by the airtight rings, thus slowing down the wear speed of the airtight rings and prolonging the service life of the airtight rings; the connection between the piston and the cylinder being provided with a support ring, the support ring being capable of supporting and positioning the piston, reducing the direct friction and collision between the piston and the cylinder wall during movement, and reducing the wear degree of the piston and the cylinder wall.

[0011] Further, the airtight ring comprises a first cutout ring and an L-shaped ring, the L-shaped ring being provided with a positioning protrusion and the positioning protrusion having a cutout at the opposite position, the L-shaped ring being overlapped on the first cutout ring, and the cutout of the first cutout ring being clamped with the positioning protrusion on the L-shaped ring. Through this kind of overlapping structure, the hydrogen leakage amount is effectively reduced, and the problem of high-pressure hydrogen easily leaking through the cutout is solved.

[0012] Furthermore, the communication hole includes an axial longitudinal hole and several radial transverse holes. The axial longitudinal hole is located at the center of the piston, and the radial transverse holes are evenly distributed on one side of the axial longitudinal hole, connecting the compression chamber with several airtight rings located on the high-pressure side. Gas enters the inner side of the airtight ring near the high-pressure side of the piston through the axial longitudinal hole and the radial transverse holes near the high-pressure side. Under the action of the gas pressure, the airtight ring is pressed against the cylinder mirror surface, enhancing the sealing effect of the airtight ring 51.

[0013] Furthermore, the aperture of the radial transverse hole near the high-pressure side is larger than that of the radial transverse hole near the low-pressure side; more high-pressure gas can enter the piston ring groove near the compression chamber 3 side through the radial transverse hole 72 with a larger aperture near the high-pressure side, which increases the pressure in the piston ring groove near the compression chamber 3 side, thereby reducing the sealing pressure difference on both sides of the airtight ring 51 on the high-pressure side.

[0014] Furthermore, the slit gap of the second slit ring near the low-pressure side is larger than the slit gap of the second slit ring near the high-pressure side. By controlling the slit gap, high-pressure gas can be appropriately leaked to the low-pressure side, thereby balancing the pressure difference between the high and low pressure sides, uniformizing the specific pressure and reducing local excessive wear.

[0015] Furthermore, the cutouts on the second cutout ring can be straight or beveled. Straight cutouts are simpler to manufacture and less expensive. When gas leaks through a straight cutout, the path is relatively direct, making the leakage easier to predict and control. Beveled cutouts increase the length of the gas leakage path, improving sealing performance. When gas passes through a beveled cutout, flow resistance is greater, resulting in less leakage compared to a straight cutout.

[0016] Furthermore, the thickness of the first cutout ring is smaller than the thickness of the second cutout ring.

[0017] Furthermore, the gas-tight ring is made of polyetheretherketone (PEEK), which is a high-temperature resistant and self-lubricating material that can prevent the high-pressure side piston ring from prematurely failing due to high temperature, thereby effectively extending the service life of the gas-tight ring.

[0018] Furthermore, the second slit ring is made of polytetrafluoroethylene (PTFE), which is a low-friction material and can effectively increase the service life of the second slit ring.

[0019] On the other hand, the present invention also provides a high-pressure hydrogen compressor, which uses the above-mentioned piston sealing mechanism.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects:

[0021] The application provides a piston sealing mechanism for a piston type high-pressure hydrogen compressor, a piston assembly movably connected in a cylinder includes a piston and a piston ring, the piston ring includes an air-tight ring and a second cutout ring, the air-tight ring is installed on the high-pressure side of the piston and closely adheres to the mirror surface of the cylinder; the air-tight ring is used in cooperation with a communication hole structure, hydrogen can only leak out from the gap between the air-tight ring and the mirror surface of the cylinder, and the air-tightness is extremely strong; the communication hole connects the cylinder and the piston ring groove on the high-pressure side, so that the high-pressure gas can enter the piston ring groove, thereby uniformly distributing the specific pressure borne by the air-tight ring. Uniform distribution of specific pressure avoids excessive local force on the air-tight ring and reduces wear caused by excessively high local pressure.

[0022] Specifically, the cutout gap of the second cutout ring close to the low-pressure side is larger than the cutout gap of the second cutout ring close to the high-pressure side; the second cutout rings with different cutout gaps are used on the low-pressure side of the piston, and the leakage amount of each cutout ring is adjusted to balance the differential pressure of the static seal. When the pressure is high, the cutout ring with a relatively large leakage amount can release part of the pressure, so that the pressure borne by each cutout ring is more uniform, thereby slowing down the wear of the cutout ring.

[0023] Specifically, different self-lubricating materials are selected for the piston rings on the high-pressure side and the low-pressure side, and the working conditions are optimized, which not only prevents the failure of the air-tight ring on the high-pressure side, but also controls the wear amount of the cutout ring on the low-pressure side, thereby significantly prolonging the overall working life of the piston ring, reducing the maintenance cost and replacement frequency. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a piston sealing mechanism for a piston type high-pressure hydrogen compressor in the embodiment of the application.

[0025] Figure 2 It is an explosion schematic diagram of an air-tight ring in the embodiment of the application.

[0026] Figure 3 It is an enlarged schematic diagram of a second cutout ring in the embodiment of the application.

[0027] Figure 4 It is an enlarged schematic diagram of a communication hole in the embodiment of the application

[0028] In the figure, 1 is a cylinder, 2 is a piston, 3 is a compression chamber, 4 is a gas valve, 5 is a piston ring, 51 is an air-tight ring, 52 is an L-shaped ring, 53 is a positioning protrusion, 54 is a second cutout ring, 55 is a first cutout ring, 6 is a supporting ring, 7 is a communication hole, 71 is an axial longitudinal hole, and 72 is a radial transverse hole. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0031] Example 1

[0032] See Figure 1 The present invention provides a piston sealing mechanism for a piston-type high-pressure hydrogen compressor, comprising a cylinder 1, a piston assembly, a compression chamber 3, an air valve 4 and a support ring 6; a piston assembly is movably connected to one end of the cylinder 1, and an air valve 4 is installed at the other end of the cylinder 1, forming a compression chamber 3 between the piston assembly and the air valve 4; a support ring 6 is provided at the connection between the piston 2 and the cylinder 1; the side of the piston assembly close to the compression chamber 3 is the high-pressure side, and the side of the piston assembly away from the compression chamber 3 is the low-pressure side. The inner surface of the cylinder 1 is processed to form a smooth cylinder mirror surface, ensuring that the piston assembly can smoothly reciprocate therein; during the compression process, the gas in the compression chamber 3 is compressed and the pressure increases, so the high-pressure side will be under higher pressure; the side away from the compression chamber 3 is the low-pressure side, and its pressure is relatively low.

[0033] The piston assembly comprises a piston 2 and piston rings 5, the piston 2 is provided with a plurality of piston ring grooves, the piston rings 5 comprise airtight rings 51 and second cutout rings 54, the piston ring grooves are used for mounting the airtight rings 51 and the second cutout rings 54; the plurality of piston rings 5 are fixed on the piston 2 through the piston ring grooves and arranged in sequence along the axis direction of the piston 2, and the airtight rings 51 are arranged on the high-pressure side, the airtight rings 51 have good sealing performance and can effectively prevent high-pressure hydrogen gas from leaking from the gap between the piston 2 and the cylinder wall, thereby ensuring the sealing performance of the compression chamber 3; the second cutout rings 54 are arranged on the low-pressure side, the cutout structure of the second cutout rings 54 allows a certain amount of gas to leak, and by reasonably designing the cutout gap, the pressure distribution on the low-pressure side of the piston assembly can be adjusted, the pressure difference is balanced, and the friction and wear between the piston rings 5 and the cylinder wall are also reduced; the end of the piston 2 close to the compression chamber 3 is provided with a communication hole 7, the communication hole 7 communicates the piston ring grooves connected by the airtight rings 51; on one hand, the pressure in the piston ring grooves where the airtight rings 51 are located tends to be uniform, thereby avoiding uneven force on the airtight rings 51 due to excessively high or low local pressure, prolonging the service life of the airtight rings 51 and ensuring the stability of the sealing effect; on the other hand, the communication hole 7 can make the high-pressure gas better transmit pressure between the airtight rings 51, so that the airtight rings 51 can be more closely attached to the cylinder wall, further improving the sealing performance of the high-pressure side and reducing the possibility of hydrogen leakage.

[0034] It should be noted that when the double-acting cylinder is working, the piston can be driven to move by the gas on both sides. Generally, when the shaft side cylinder is driven by the gas, the other side (the rod side) is a low-pressure side formed by exhaust gas; the differential cylinder usually has different piston cavities, and the balance cavity is used for balancing the axial force, which should all be considered as the protection scope of the present patent.

[0035] For example, the piston 2 is provided with nine piston rings 5 and one support ring 6, forming a piston sealing structure, wherein five airtight rings 51 are arranged on the high-pressure side of the piston 2, and four second cutout rings 54 are arranged on the low-pressure side of the piston 2.

[0036] Embodiment 2

[0037] In the conventional piston ring sealing structure, the cutout is often the main path for high-pressure hydrogen gas leakage. Because high-pressure hydrogen gas has strong penetrability, it is easy to leak out through the small gap of the cutout.

[0038] Reference Figures 2 to 3On the basis of Example 1, the airtight ring 51 and the second notch ring 54 are further described; the airtight ring 51 includes a first notch ring 55 and an L-shaped ring 52, and the L-shaped ring 52 is provided with a positioning protrusion 53 and a notch at a relative position of the positioning protrusion 53. When superimposed, the notch of the first notch ring 55 is just engaged with the positioning protrusion 53 on the L-shaped ring 52; ensure that the notch of the first notch ring 55 is staggered with the notch on the L-shaped ring 52, and the notch on the L-shaped ring 52 is surrounded and sealed by the L-shaped ring 52. Through this overlapping structure, the possibility of high-pressure hydrogen leakage is greatly reduced. The setting of multiple sealing links, such as the staggered notches and the surrounding sealing of the L-shaped ring itself, all have a hindering effect on the leakage of hydrogen, so that the hydrogen encounters many resistances when trying to leak, thereby effectively reducing the leakage amount.

[0039] For example, the cut gap of the second cut ring 54 close to the low-pressure side is larger than the cut gap of the second cut ring 54 close to the high-pressure side. By controlling the cut gap, high-pressure gas can be appropriately leaked to the low-pressure side, thereby balancing the pressure difference between the high and low-pressure sides. The uniform specific pressure can reduce local excessive wear; the cut on the second cut ring 54 is a straight cut or an oblique cut.

[0040] Preferably, the material of the airtight ring 51 is polyetheretherketone (PEEK). During operation, the temperature of the hydrogen in the compression chamber 3 increases due to compression, so the temperature borne by the airtight ring 51 is higher than that of the second cut ring 54. Polyetheretherketone (PEEK) is a high-temperature resistant self-lubricating material, which can prevent the airtight ring 51 from premature failure due to high temperature and increase the service life of the airtight ring.

[0041] Preferably, the material of the second incision ring 54 is polytetrafluoroethylene. During operation, the temperature borne by the second incision ring 54 is lower than the temperature borne by the airtight ring 51. Therefore, the main consideration when selecting the material is the friction coefficient. Polytetrafluoroethylene is a low friction coefficient material, which can effectively increase the service life of the second incision ring 54.

[0042] Preferably, the thickness of the first notch ring 55 is smaller than the thickness of the second notch ring 54 .

[0043] Example 3

[0044] See Figure 4 Based on Example 2, the connecting hole 7 is further described. The connecting hole 7 includes an axial longitudinal hole 71 and a plurality of radial transverse holes 72. The axial longitudinal hole 71 extends along the central axis of the piston 2 and is the main channel for gas transmission inside the piston 2. The radial transverse holes 72 are perpendicular to the axial longitudinal hole 71 and connect the axial longitudinal hole 71 with the piston ring groove on the high-pressure side, so that the gas in the cylinder can enter each piston ring groove through the axial longitudinal hole 71 and the radial transverse holes 72.

[0045] Preferably, the cutout gap of the second cutout ring 54 near the low-pressure side is larger than the cutout gap of the second cutout ring 54 near the high-pressure side. During the operation of a piston-type high-pressure hydrogen compressor, there is a significant pressure difference between the high-pressure and low-pressure sides of the piston assembly. The gas pressure is higher near the high-pressure side, while the gas pressure is lower near the low-pressure side. By designing the cutout gap of the second cutout ring 54 near the low-pressure side to be larger than the cutout gap of the second cutout ring 54 near the high-pressure side, the cutout gap can be used to adjust the amount of gas leakage, thereby balancing the pressure at different locations.

[0046] Preferably, the diameter of the radial transverse hole 72 close to the high-pressure side is larger than that of the radial transverse hole 72 close to the low-pressure side.

[0047] During operation, the gas in the compression chamber 3 is in a high-pressure state. Since the diameter of the radial transverse hole 72 near the high-pressure side is larger than that near the low-pressure side, more high-pressure gas can enter the piston ring groove near the compression chamber 3 through the radial transverse hole 72 near the high-pressure side with a larger diameter. This increases the pressure in the piston ring groove near the compression chamber 3, that is, the pressure in the piston ring groove near the high-pressure side increases, thereby reducing the sealing pressure difference on both sides of the gas-tight ring 51 on the high-pressure side. At the same time, the gas enters the inner side of the gas-tight ring 51 near the high-pressure side of the piston through the axial longitudinal hole 71 and the radial transverse hole 72 near the high-pressure side. Under the action of the gas pressure, the gas-tight ring 51 is pressed against the cylinder mirror surface.

[0048] By reducing the sealing pressure differential on both sides of the airtight ring 51 near the high-pressure side, the pressure and friction on the airtight ring 51 are reduced, thereby slowing its wear rate. This helps to extend the service life of the airtight ring 51 and reduce the occurrence of sealing performance degradation and equipment failure caused by wear of the airtight ring 51. At the same time, the specific pressure experienced by each airtight ring 51 is made uniform, avoiding the problem of excessive wear or sealing failure of some airtight rings due to uneven specific pressure distribution, and ensuring that all airtight rings 51 can operate under relatively balanced working conditions.

[0049] Introducing pressure into the inner side of the gas-tight ring 51 near the high-pressure side causes the gas-tight ring 51 to be in close contact with the cylinder mirror surface, thereby enhancing the sealing effect of the gas-tight ring 51. This effectively prevents high-pressure gas from leaking from the gap between the piston 2 and the cylinder wall, thereby improving the sealing performance of the entire piston sealing mechanism.

[0050] Preferably, the present invention also provides a high-pressure hydrogen compressor, which utilizes the above-mentioned piston sealing mechanism.

[0051] Compared with the traditional sealing structure, the present invention proposes a piston through hole 7, and by combining piston rings 5 ​​with different structures and materials, while ensuring the airtightness of the piston ring 5, improvements are made in terms of uniform pressure distribution, improved high temperature resistance and reduced wear. While effectively controlling the hydrogen leakage, the piston ring group pressure distribution is uniformly distributed, the wear rate of the piston ring group is reduced, and the service life of the piston ring 5 is greatly improved.

[0052] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0053] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A piston sealing mechanism for a piston-type high-pressure hydrogen compressor, characterized in that: The invention comprises a cylinder (1), wherein one end of the cylinder (1) is internally movably connected to a piston assembly, and the other end is provided with an air valve (4), and a compression chamber (3) is formed between the piston assembly and the air valve (4); the side of the piston assembly close to the compression chamber (3) is a high-pressure side, and the side of the piston assembly away from the compression chamber (3) is a low-pressure side; The piston assembly comprises a piston (2) and a piston ring (5), wherein the piston (2) is provided with a plurality of piston ring grooves, and the piston ring (5) comprises an airtight ring (51) and a second cut ring (54); the plurality of piston rings (5) are fixed to the piston (2) through the piston ring grooves, and the piston rings (5) are arranged in sequence along the axis direction of the piston (2), with the high-pressure side being provided with the airtight ring (51) and the low-pressure side being provided with the second cut ring (54); A connecting hole (7) is provided at the end of the piston (2) close to the compression chamber (3), and the connecting hole (7) connects the piston ring grooves connected to the plurality of airtight rings (51); a supporting ring (6) is provided at the connection between the piston (2) and the cylinder (1).

2. The piston sealing mechanism for a piston-type high-pressure hydrogen compressor according to claim 1, characterized in that: The airtight ring (51) comprises a first notch ring (55) and an L-shaped ring (52); a positioning protrusion (53) is provided on the L-shaped ring (52), and a notch is provided at a relative position of the positioning protrusion (53); the L-shaped ring (52) is superimposed on the first notch ring (55), and the notch of the first notch ring (55) is engaged with the positioning protrusion (53) on the L-shaped ring (52).

3. The piston sealing mechanism for a piston-type high-pressure hydrogen compressor according to claim 1, characterized in that: The communicating hole (7) comprises an axial longitudinal hole (71) and a plurality of radial transverse holes (72). The axial longitudinal hole (71) is arranged at the center of the piston (2), and the plurality of radial transverse holes (72) are evenly distributed on one side of the axial longitudinal hole (71), connecting the compression chamber (3) with a plurality of airtight rings (51) arranged on the high-pressure side.

4. The piston sealing mechanism for a piston-type high-pressure hydrogen compressor according to claim 3, characterized in that: The diameter of the radial transverse hole (72) close to the high-pressure side is larger than the diameter of the radial transverse hole (72) close to the low-pressure side.

5. The piston sealing mechanism for a piston-type high-pressure hydrogen compressor according to claim 1, characterized in that: The cutout gap of the second cutout ring (54) close to the low-pressure side is larger than the cutout gap of the second cutout ring (54) close to the high-pressure side.

6. The piston sealing mechanism for a piston-type high-pressure hydrogen compressor according to claim 5, characterized in that: The cut on the second cut ring (54) is a straight cut or an oblique cut.

7. The piston sealing mechanism for a piston-type high-pressure hydrogen compressor according to claim 2, characterized in that: The thickness of the first notch ring (55) is smaller than the thickness of the second notch ring (54).

8. The piston sealing mechanism for a piston-type high-pressure hydrogen compressor according to claim 1, characterized in that: The material of the airtight ring (51) is polyetheretherketone material.

9. The piston sealing mechanism for a piston-type high-pressure hydrogen compressor according to claim 1, characterized in that: The second notch ring (54) is made of polytetrafluoroethylene.

10. A high-pressure hydrogen compressor, characterized in that: The piston sealing mechanism according to any one of claims 1 to 9 is used.

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