Full-working-condition breakage, loosening and leakage prevention structure of high-pressure gas diaphragm compressor

Abstract

This invention discloses a full-condition anti-breakage, anti-loosening, and anti-leakage structure for a high-pressure gas diaphragm compressor, comprising an oil-side cylinder head body, a gas-side cylinder head body, a composite support and anti-friction structure, a symmetrical oblique-hole oil distribution structure, and a constant-pressure tightening anti-loosening and anti-leakage mechanism for the exhaust rod. The composite support and anti-friction structure supports, guides, and transfers load on the plunger rod through a dynamic pressure groove unit, a main directional ring, and an elastic stress transfer guide ring. The constant-pressure tightening anti-loosening and anti-leakage mechanism for the exhaust rod places the exhaust valve inside the exhaust rod and improves the sealing stability of the exhaust end through an NPT threaded collar, a toothed sealing gasket, and a dynamic impedance matching section. The symmetrical oblique-hole oil distribution structure improves the uniformity of oil distribution in the diaphragm oil-side cavity through an annular pressure equalizing groove, a radial pressure equalizing groove, an inner ring oil distribution hole, an outer ring oil distribution hole, and a radially symmetrical oil distribution channel. This invention helps reduce the risk of plunger rod wear and breakage, reduces exhaust rod loosening and leakage, and improves the operational reliability of the high-pressure gas diaphragm compressor.

Description

Technical Field

[0001] This invention relates to the field of high-pressure gas diaphragm compressor technology, specifically to a high-pressure gas diaphragm compressor with a structure that prevents breakage, loosening, and leakage under all operating conditions. Background Technology

[0002] High-pressure gas diaphragm compressors typically use a plunger rod to compress hydraulic oil, which in turn drives the diaphragm to reciprocate, thereby achieving gas intake, compression, and discharge. Because the gas side and oil side are isolated by a diaphragm, this type of compressor is widely used in pressurization scenarios involving hydrogen, nitrogen, helium, natural gas, and other high-purity or high-pressure gases. With increasing operating pressure, the equipment faces higher demands on the reliability of the exhaust end seal, the stability of the plunger rod support, and the uniformity of oil distribution on the oil side under conditions such as start-up, pressurization, steady-state operation, pressure fluctuations, and frequent start-stop cycles.

[0003] In existing high-pressure gas diaphragm compressors, the exhaust valve is typically positioned and pre-tightened using an exhaust rod, chuck, bolts, or similar clamping structure. The exhaust rod transmits the external pre-tightening force to the exhaust valve to ensure a seal between the exhaust valve and the cylinder head. While this type of structure is relatively easy to assemble and maintain, the exhaust rod and its clamping structure are affected by gas pulsation, equipment vibration, and temperature changes during the periodic discharge of high-pressure gas. After long-term operation, the pre-tightening force of the bolts or clamping components may decrease, leading to insufficient clamping force on the sealing surface and potentially causing leakage near the exhaust valve or at the exhaust rod connection point. For small molecule gases such as hydrogen, this leakage risk is more easily exposed. Furthermore, existing structures primarily focus on the clamping seal between the exhaust valve and the exhaust rod, neglecting the potential sealing gaps that may form at the exhaust valve tip or between the exhaust rod and the cylinder head. Under conditions of significant gas impact or pressure fluctuations, localized leakage risks may still exist.

[0004] Regarding the operation of the plunger rod, the plunger rod reciprocates within the plunger sleeve, pushing the hydraulic oil to build up pressure. Its stress state includes not only axial loads but also lateral forces caused by uneven pressure distribution within the oil chamber, assembly deviations, starting impacts, and alternating loads. Existing technologies commonly employ improvements such as increasing the plunger rod material strength, enlarging the transition radius, adjusting the rod cross-section, optimizing heat treatment processes, or adding ordinary guide components. These methods can improve the plunger rod's load-bearing capacity to some extent, but they primarily strengthen the rod itself or local structures. When the pressure distribution within the high-pressure oil chamber is uneven or the plunger rod experiences slight eccentricity, localized contact, uneven wear, or stress concentration may still occur between the plunger rod and the plunger sleeve. Under long-term operation under high pressure and alternating loads, these problems may further develop into fatigue damage, affecting the service life of the plunger rod and related sealing structures.

[0005] Regarding oil distribution on the oil side, the existing diaphragm compressor's oil hole structure is typically used primarily as a hydraulic oil passage. The influence of the hole position, orientation, and connectivity between the holes on the pressure distribution within the oil-side cavity is often insufficiently considered in some designs. When hydraulic oil enters the diaphragm's oil-side cavity, if there is localized flow concentration or uneven pressure build-up, it can lead to differences in pressure build-up rates across different areas of the diaphragm's oil side, resulting in uneven local stress on the diaphragm. Simultaneously, unevenly distributed drain holes in the plunger rod end cavity can also generate pressure disturbances or lateral reaction forces during pressure build-up, adversely affecting the plunger rod's alignment. This issue requires even greater attention under high-pressure, rapid-pressure-increasing, or frequent start-stop conditions.

[0006] Regarding the issues of oil distribution and pressure equalization on the oil side, existing technologies have provided relevant improvements. For example, patent publication number CN117307457A discloses a diaphragm head assembly and a diaphragm compressor. This solution mainly alters the flow path of hydraulic oil within the oil-side diaphragm cavity through the cooperation of the guide plate, distribution plate, and distribution area, causing the hydraulic oil to flow from the edge of the distribution plate towards the center. This improves the diaphragm adhesion process, reduces clearance volume, and increases volumetric efficiency. While this structure can improve oil distribution on the diaphragm oil side, it primarily relies on the guide plate and distribution plate to guide the oil flow. It does not address the structure of setting inner ring oil distribution holes, outer ring oil distribution holes, annular pressure equalization grooves, radial pressure equalization grooves, and radially symmetrical oil distribution channels on the end face of the piston rod pressurization chamber. Nor does it further consider reducing the adverse effects of the hydraulic oil jetting or discharge process on the piston rod alignment through symmetrical hole arrangement. Another example is patent publication number CN200968275Y, which discloses a novel diaphragm compressor cylinder structure. This design incorporates pressure equalization grooves and through-holes on the oil side of the diaphragm compressor, which helps improve the pressure distribution on the diaphragm oil side. However, since this structure primarily uses pressure equalization grooves and through-holes to achieve oil distribution, this design focuses more on the pressure equalization effect on the diaphragm oil side, and pays less attention to the symmetry and tilt direction of the oil distribution holes and oil discharge channels, as well as the impact of pressure reaction force on the plunger rod alignment and wear.

[0007] In summary, existing high-pressure gas diaphragm compressors still have room for improvement in terms of exhaust rod sealing, plunger rod support and guidance, and oil-side pressure distribution. How to improve the sealing stability at the exhaust rod, reduce the risk of plunger rod wear and stress concentration, and improve the oil distribution uniformity of the diaphragm oil-side cavity without significantly increasing the overall complexity of the compressor is a technical problem that needs to be solved in this field. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the defects in the existing high-pressure gas diaphragm compressor, such as the exhaust pressure rod being easily affected by vibration and pressure fluctuations, resulting in sealing leakage; the plunger rod being prone to uneven wear and stress concentration during startup and high-pressure operation; and uneven oil distribution in the diaphragm oil side cavity affecting the centering stability of the plunger rod. The present invention provides a high-pressure gas diaphragm compressor with a full-condition anti-breakage, anti-loosening, and anti-leakage structure, which can effectively solve the problems in the background technology.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a full-condition anti-breakage, anti-loosening, and anti-leakage structure for a high-pressure gas diaphragm compressor, comprising an oil-side cylinder head body, a gas-side cylinder head body, a composite support and anti-friction structure, a symmetrical oblique-hole oil distribution structure, and a constant-pressure anti-loosening and anti-leakage mechanism for the exhaust pressure rod. The oil-side cylinder head body and the gas-side cylinder head body are arranged opposite to each other. The composite support and anti-friction structure is installed on the oil-side cylinder head body. The symmetrical oblique-hole oil distribution structure is located on the side of the oil-side cylinder head body near the diaphragm oil-side cavity. The constant-pressure mechanism for the exhaust pressure rod... The anti-loosening and anti-leakage mechanism is installed on the air-side cylinder head body; the composite support and anti-friction structure includes a plunger sleeve, a plunger rod, a sealing area, a main directional ring, a dynamic pressure groove unit, and an elastic stress transfer guide ring. The plunger rod passes through the plunger sleeve and can reciprocate along the axial direction of the plunger sleeve; the dynamic pressure groove unit is set on the outer circumferential surface of the plunger rod near the high-pressure oil chamber; the main directional ring is set between the plunger rod and the plunger sleeve and is located on the side of the sealing area near the high-pressure oil chamber; the elastic stress transfer guide ring is set on the side of the plunger sleeve away from the high-pressure oil chamber. The symmetrical inclined hole oil distribution structure is connected to the pressurization chamber of the plunger rod and includes an annular pressure equalizing groove, a radial pressure equalizing groove, an inner ring oil distribution hole, an outer ring oil distribution hole, and a radially symmetrical oil distribution channel. The inner ring oil distribution hole and the outer ring oil distribution hole are respectively arranged symmetrically around the axis of the plunger rod. The inner ring oil distribution hole and the outer ring oil distribution hole are respectively connected through the corresponding annular pressure equalizing groove. The radial pressure equalizing groove is connected to the annular pressure equalizing groove. The radially symmetrical oil distribution channel is connected to the annular pressure equalizing groove and / or the outer ring oil distribution hole. The constant pressure anti-loosening and anti-leakage mechanism of the exhaust rod is installed in the mounting hole of the air-side cylinder head body and includes an outlet section dynamic impedance matching section, a toothed gasket, an exhaust valve, an inlet section dynamic impedance matching section, an NPT threaded collar, an NPT threaded area, and an exhaust rod. The exhaust rod is threadedly connected to the air-side cylinder head body through the NPT threaded area. The exhaust valve is located in the inlet end cavity of the exhaust rod. The NPT threaded collar is threadedly engaged with the internal cavity of the exhaust rod and is used to apply axial preload to the exhaust valve. The toothed gaskets are respectively located between the exhaust valve and the exhaust rod and between the exhaust rod and the air-side cylinder head body.

[0010] Furthermore, the oil-side cylinder head body is provided with a plunger mounting hole extending along the axial direction of the plunger rod. The plunger sleeve is fixedly installed in the plunger mounting hole of the oil-side cylinder head body. The inner hole of the plunger sleeve is coaxially arranged with the plunger rod. The end of the plunger rod near the high-pressure oil chamber is arranged towards the symmetrical inclined hole oil distribution structure, so that when the plunger rod reciprocates, it can deliver hydraulic oil to the symmetrical inclined hole oil distribution structure.

[0011] Furthermore, the dynamic pressure groove unit, the main directional ring, the sealing area, and the elastic stress transfer guide ring are arranged sequentially along the axial direction of the plunger rod, and the main directional ring and the elastic stress transfer guide ring are spaced apart along the axial direction of the plunger rod to form a two-point support structure between the plunger rod and the plunger sleeve.

[0012] The dynamic pressure groove unit includes at least one set of herringbone bidirectional spiral grooves. The herringbone bidirectional spiral grooves include a first spiral groove segment and a second spiral groove segment. The spiral directions of the first spiral groove segment and the second spiral groove segment are opposite, and they converge in the axial middle region of the plunger rod.

[0013] Furthermore, the herringbone bidirectional spiral groove has a spiral angle of 15° to 25°, a groove depth of 0.2 mm to 0.3 mm, a groove width of 0.8 mm to 1.2 mm, and a spiral groove head of 4 to 6. The axial length of the herringbone bidirectional spiral groove on the outer circumference of the plunger rod is 30 mm to 50 mm.

[0014] Furthermore, the elastic stress transfer guide ring includes an inner layer, a middle layer, and an outer layer arranged sequentially from the inside to the outside; the inner layer slides with the plunger rod; the middle layer is an elastic layer used to generate elastic deformation when the plunger rod is subjected to lateral force, and to convert at least part of the bending load on the plunger rod into a radial load; the outer layer is fixedly connected to the inner wall of the plunger sleeve and is used to transfer the radial load to the plunger sleeve.

[0015] Furthermore, the main guide ring is a QSn4-4-2.5 tin bronze guide ring or a polytetrafluoroethylene-filled guide ring; the inner layer of the elastic stress transfer guide ring is a QSn4-4-2.5 tin bronze layer or a polytetrafluoroethylene-filled layer, the middle layer is a stainless steel metal rubber layer or a multi-layer corrugated spring sheet layer, and the outer layer is a 42CrMo alloy steel layer.

[0016] Furthermore, the intake end of the exhaust rod is provided with a cavity for accommodating the exhaust valve and a sealing step for supporting the exhaust valve. The exhaust valve is pressed against the sealing step by an NPT threaded collar.

[0017] The toothed seal includes a first toothed seal and a second toothed seal. The first toothed seal is disposed between the exhaust valve and the exhaust rod, and the second toothed seal is disposed between the exhaust rod and the cylinder head body on the air side. The toothed gasket is a 316L stainless steel toothed metal gasket, and the sealing surface of the toothed gasket is provided with multiple concentric serrated ridges.

[0018] The air-side cylinder head body is provided with an axially extending groove, the top of the exhaust rod extends into the groove, and the second toothed seal is provided in the groove and located between the exhaust rod and the air-side cylinder head body; the exhaust rod is threaded with the air-side cylinder head body through the NPT thread area to apply axial preload to the second toothed seal.

[0019] Furthermore, the inlet section dynamic impedance matching section is set on the inner hole of the NPT threaded collar, and the outlet section dynamic impedance matching section is set on the inner hole of the exhaust pressure rod. Both the inlet and outlet dynamic impedance matching sections are three-section gradually changing micro-diameter tube structures. The three-section gradually changing micro-diameter tube structure includes an inlet section, an intermediate micro-shrinking section, and an outlet gradually expanding section. The diameter reduction ratio of the intermediate micro-shrinking section is 3% to 8%. The total length of the inlet and outlet dynamic impedance matching sections is 2.5 to 3 times the corresponding tube diameter, and their inner walls have a smooth transition structure.

[0020] Furthermore, the end face of the pressurization chamber of the plunger rod is provided with a central circular pressure equalization area, and the radial pressure equalization grooves are arranged symmetrically in a cross shape, connecting the central circular pressure equalization area, the inner ring pressure equalization groove and the outer ring pressure equalization groove. There are five or more sets of inner ring oil distribution holes, which are directly connected to the oil side cavity of the diaphragm. At least two sets of inner ring oil distribution holes are arranged in a cross shape and are inclined inward along the direction of the plunger rod. The remaining inner ring oil distribution holes are inclined outward along the direction of the plunger rod. The inclination angle of the inner ring oil distribution holes is 15° to 25°.

[0021] Furthermore, the number of outer ring oil distribution holes is six or more and is an even number. The outer ring oil distribution holes are directly connected to the diaphragm oil side cavity and are axially inclined outward along the direction of the plunger rod. The inclination angle of the outer ring oil distribution holes is 20° to 35°. The radially symmetrical oil distribution channel includes a radial hole formed on the circumferential surface of the pressurization chamber near the end face of the plunger rod, and a through hole formed on the oil-side cylinder head body and correspondingly communicating with the radial hole; the radial hole communicates with the annular equalizing groove of the outer ring, and the through hole is used to guide the hydraulic oil led out through the radial hole to the outer region of the diaphragm oil-side chamber; the number of radial holes is half the number of oil distribution holes of the outer ring, and the radial holes and the oil distribution holes of the outer ring are symmetrically arranged at intervals in the circumferential direction; the through hole is axially inclined outward along the direction of the plunger rod, with an inclination angle of 20° to 35°.

[0022] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention improves the support state of the plunger rod during high-pressure reciprocating motion through a composite support and anti-friction structure. The dynamic pressure groove unit is set on the outer circumferential surface of the plunger rod near the high-pressure oil chamber end, which helps to form a dynamic pressure oil film between the plunger rod and the plunger sleeve during the reciprocating motion of the plunger rod, thereby reducing the direct contact between the two. The main guide ring is located on the side of the sealing area near the high-pressure oil chamber, which can provide mechanical guidance for the plunger rod during startup, low-speed operation, or when the oil film has not yet been stably formed. The elastic stress transfer guide ring and the main guide ring are arranged axially at intervals, which can form a two-point support structure. After the above structures are combined, it is beneficial to reduce the risk of plunger rod wobble, uneven wear, and local stress concentration, and improve the operational stability of the plunger rod under startup, normal operation, and pressure fluctuation conditions.

[0023] 2. This invention further improves the force transmission path of the plunger rod when it is subjected to lateral force or bending load by using an elastic stress transfer guide ring. The elastic stress transfer guide ring includes an inner layer, a middle layer, and an outer layer. The inner layer slides with the plunger rod, the middle layer is an elastic layer, and the outer layer is fixedly connected to the inner wall of the plunger sleeve. When the plunger rod is subjected to lateral impact or bending load, the middle layer can generate elastic deformation, absorb part of the impact energy, and convert part of the bending load into a radial load before transmitting it to the plunger sleeve. This structure is different from simply increasing the strength of the plunger rod material or increasing the rod size. It can improve the stress environment of the plunger rod and reduce the risk of fatigue damage under long-term alternating loads without significantly changing the basic structure of the plunger rod.

[0024] 3. This invention improves the sealing stability of the exhaust end through a constant pressure tightening mechanism for the exhaust rod to prevent loosening and leakage. The exhaust valve is located in the intake cavity of the exhaust rod and is pressed against the sealing step inside the exhaust rod by an NPT threaded collar. The exhaust rod is threadedly connected to the cylinder head body on the air side through the NPT threaded area. Toothed sealing gaskets are respectively set between the exhaust valve and the exhaust rod, and between the exhaust rod and the cylinder head body on the air side. Thus, an internal pressure seal is formed between the exhaust valve and the exhaust rod, and an external pressure seal is formed between the exhaust rod and the cylinder head body on the air side. The multi-ring toothed sealing structure can increase the sealing contact line, which is beneficial to maintain a more stable sealing state under vibration, temperature change and pressure fluctuation conditions, and reduce the risk of exhaust rod loosening and leakage near the exhaust valve.

[0025] 4. This invention also mitigates airflow impact during high-pressure exhaust by using dynamic impedance matching sections at the inlet and outlet. The dynamic impedance matching section at the inlet is located on the inner hole of the NPT threaded collar, and the dynamic impedance matching section at the outlet is located on the inner hole of the exhaust rod. Both can be constructed using a three-section gradually decreasing micro-diameter tube structure consisting of an inlet section, an intermediate miniaturized section, and an outlet gradually expanding section. This structure allows the high-pressure gas to experience a relatively gentle cross-sectional change when entering and exiting the exhaust rod, thereby reducing local pressure impact and gas pulsation caused by abrupt flow changes. This effect can reduce the alternating load on the exhaust valve, exhaust rod, and their connecting parts, and, in conjunction with the toothed gasket and NPT threaded pre-tightening structure, improve the reliability of the exhaust end structure under high-pressure exhaust conditions.

[0026] 5. This invention improves the uniformity of oil distribution in the diaphragm oil-side cavity through a symmetrical oblique-hole oil distribution structure, and reduces the adverse effects of oil pressure disturbance on plunger rod alignment. The annular pressure equalizing groove, radial pressure equalizing groove, inner ring oil distribution hole, outer ring oil distribution hole, and radially symmetrical oil distribution channel are interconnected, allowing the hydraulic oil to undergo a certain degree of pressure equalization and flow distribution before entering the diaphragm oil-side cavity. The inner and outer ring oil distribution holes are symmetrically arranged around the plunger rod axis, and the hydraulic oil is guided to act on the central and edge areas of the oil-side cavity through the inward and outward inclined oil distribution holes, which helps to reduce local pressure build-up lag and uneven diaphragm stress. The radially symmetrical oil distribution channel and the outer ring oil distribution hole are symmetrically arranged at intervals, which can make the oil reaction force cancel each other out or partially cancel each other out, thereby reducing the eccentric disturbance to the plunger rod during pressure build-up. When this oil distribution structure is combined with the composite support and anti-friction structure, it helps to simultaneously improve the oil-side pressure equalization effect and the plunger rod running stability. Attached Figure Description

[0027] Figure 1 This is a schematic diagram showing the positions of the overall arrangement of the structures in this invention; Figure 2 This is a schematic diagram of the composite support and wear-reducing structure of the diaphragm compressor plunger rod of the present invention; Figure 3 This is an enlarged structural diagram of point A in the present invention; Figure 4 This is a schematic diagram of the constant pressure tightening mechanism for preventing loosening and leakage of the exhaust pressure rod according to the present invention; Figure 5 This is a schematic diagram of the toothed sealing gasket structure of the present invention; Figure 6 This is a schematic diagram of the symmetrical oblique hole oil distribution mechanism of the present invention; Figure 7 This is an enlarged structural diagram of section I of the present invention; Figure 8 This is a schematic diagram of the elastic stress transfer guide ring structure of the present invention.

[0028] In the diagram: 1. Oil-side cylinder head body; 2. Composite support and anti-friction structure; 3. Symmetrical oblique hole oil distribution structure; 4. Exhaust rod constant pressure tightening anti-loosening and anti-leakage mechanism; 5. Gas-side cylinder head body; 6. Piston sleeve; 7. Piston rod; 8. Sealing area; 9. Main directional ring; 10. Dynamic pressure groove unit; 11. Elastic stress transfer guide ring; 12. Outlet section dynamic impedance matching section; 13. Toothed seal; 14. Exhaust valve; 15. Inlet section dynamic impedance matching section; 16. NPT threaded collar; 17. NPT threaded area; 18. Exhaust rod; 19. Annular pressure equalizing groove; 20. Radial pressure equalizing groove; 21. Inner ring oil distribution hole; 22. Outer ring oil distribution hole; 23. Radial symmetrical oil distribution channel; 23a. Radial hole; 23b. Through hole; 24. Herringbone bidirectional spiral groove; 25. Piston mounting hole. Detailed Implementation

[0029] The following is combined Figures 1 to 8 The following description further illustrates the specific embodiments of the present invention. It should be understood that the following embodiments are used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Without departing from the technical concept of the present invention, those skilled in the art can make adaptive adjustments to the specific dimensions, materials and connection methods according to the compressor pressure rating, displacement, plunger rod size, gas medium and processing conditions.

[0030] In this embodiment, the plunger rod 7 refers to the reciprocating rod used to compress hydraulic oil at the hydraulic end of the diaphragm compressor, and can also be called a piston rod; the plunger sleeve 6 refers to the sleeve that slides with the plunger rod 7 and provides guidance and support for it, and can also be called a piston sleeve; for ease of explanation, the plunger rod 7 and plunger sleeve 6 will be used uniformly in the following text.

[0031] I. Overall Structure like Figure 1 As shown, the present invention provides a high-pressure gas diaphragm compressor full-condition anti-breakage, anti-loosening, and anti-leakage structure, including an oil-side cylinder head body 1, a composite support and anti-friction structure 2, a symmetrical oblique hole oil distribution structure 3, an exhaust pressure rod constant pressure anti-loosening and anti-leakage mechanism 4, and a gas-side cylinder head body 5.

[0032] The oil-side cylinder head body 1 and the gas-side cylinder head body 5 are arranged opposite each other, and the diaphragm assembly is installed between them. The oil-side cylinder head body 1 is located on the oil side of the diaphragm assembly, and the gas-side cylinder head body 5 is located on the gas side of the diaphragm assembly. When the compressor is working, the plunger rod 7 reciprocates in the plunger sleeve 6 and compresses the hydraulic oil. The hydraulic oil enters the oil-side cavity of the diaphragm through the symmetrical inclined hole oil distribution structure 3, causing the diaphragm to undergo periodic deformation. After the gas is compressed on the gas side of the diaphragm, it is discharged through the exhaust valve 14 and the exhaust rod 18.

[0033] The composite support and anti-friction structure 2 is installed on the oil-side cylinder head body 1 to support the plunger rod 7 and reduce the risk of uneven wear and bending damage to the plunger rod 7; the symmetrical inclined hole oil distribution structure 3 is set on the side of the oil-side cylinder head body 1 near the diaphragm oil-side cavity and is connected to the pressure boosting cavity of the plunger rod 7 to equalize and distribute the hydraulic oil; the constant pressure tightening anti-loosening and anti-leakage mechanism 4 of the exhaust pressure rod is installed on the air-side cylinder head body 5 to tighten and seal the exhaust valve 14 and buffer the exhaust airflow.

[0034] II. Composite Support and Wear Reduction Structure like Figure 2 and Figure 3 As shown, the composite support and friction reduction structure 2 includes a plunger sleeve 6, a plunger rod 7, a sealing area 8, a main directional ring 9, a dynamic pressure groove unit 10, and an elastic stress transfer guide ring 11. The oil-side cylinder head body 1 is provided with a plunger mounting hole 25 extending axially along the plunger rod 7, and the plunger sleeve 6 is fixedly installed in the plunger mounting hole 25. The plunger sleeve 6 can be fixed to the oil-side cylinder head body 1 by interference fit, step limit, gland clamping, threaded connection, or a combination of the above methods. The plunger rod 7 passes through the plunger sleeve 6 and can reciprocate axially along the plunger sleeve 6. The end of the plunger rod 7 near the high-pressure oil chamber faces the symmetrical inclined hole oil distribution structure 3, so that the plunger rod 7 can deliver hydraulic oil pressure to the diaphragm oil-side cavity when it is pushed forward.

[0035] The plunger rod 7 can be made of 38CrMoAlA alloy steel, and its surface can be nitrided to improve its surface hardness and wear resistance; the plunger sleeve 6 can be made of 42CrMo alloy steel, and its inner hole is precision machined to form a sliding fit with the plunger rod 7; as a specific embodiment, the plunger rod 7 has a diameter of 60mm and a total length of 600mm, and the surface roughness of the inner hole of the plunger sleeve 6 is not greater than Ra0.4μm; the above dimensions can be adjusted according to the compressor pressure rating, displacement and structural space.

[0036] The dynamic pressure groove unit 10 is disposed on the outer circumferential surface of the plunger rod 7 near the high-pressure oil chamber; the dynamic pressure groove unit 10 includes at least one set of herringbone bidirectional spiral grooves 24; the herringbone bidirectional spiral grooves 24 include a first spiral groove segment and a second spiral groove segment, the spiral directions of the first spiral groove segment and the second spiral groove segment are opposite, and they intersect in the axial middle region of the plunger rod 7.

[0037] During the compression stroke of the plunger rod 7, the first helical groove section can pump the oil between the plunger rod 7 and the plunger sleeve 6; during the return stroke of the plunger rod 7, the second helical groove section can pump the oil accordingly; through the cooperation of the two helical groove sections with opposite directions, during the reciprocating motion of the plunger rod 7, the oil can form a dynamic pressure oil film between the plunger rod 7 and the plunger sleeve 6, thereby reducing the direct contact between the plunger rod 7 and the plunger sleeve 6.

[0038] The herringbone bidirectional spiral groove 24 can be formed by CNC milling, grinding, electrical discharge machining, or laser processing. After processing, the groove opening can be chamfered or rounded to reduce local stress concentration. As a preferred embodiment, the herringbone bidirectional spiral groove 24 has a spiral angle of 15° to 25°, a groove depth of 0.2mm to 0.3mm, a groove width of 0.8mm to 1.2mm, a spiral groove head of 4 to 6, and an axial length of 30mm to 50mm. In a specific embodiment, the spiral angle is 20°, the groove depth is 0.25mm, the groove width is 1.0mm, the spiral groove head is 4, the axial length is 40mm, and the groove bottom fillet is R0.15mm.

[0039] The main guide ring 9 is disposed between the plunger rod 7 and the plunger sleeve 6, and is located on the side of the sealing area 8 near the high-pressure oil chamber. The main guide ring 9 can be embedded in the annular mounting groove on the inner wall of the plunger sleeve 6, or it can be fixed by press fitting, limiting step or retaining ring. The main guide ring 9 is used to provide mechanical guidance to the plunger rod 7 during startup, low-speed operation or when the hydrodynamic oil film has not yet been stably formed, and to reduce the direct transmission of lateral force to the sealing area 8. The main guide ring 9 can be made of QSn4-4-2.5 tin bronze, filled with polytetrafluoroethylene or other oil-resistant, wear-resistant, low-friction materials. In one specific embodiment, the axial length of the main guide ring 9 is 25 mm and the wall thickness is 4 mm.

[0040] The elastic stress transfer guide ring 11 is located on the side of the plunger sleeve 6 away from the high-pressure oil chamber, and is spaced apart from the main guide ring 9 along the axial direction of the plunger rod 7; the main guide ring 9 and the elastic stress transfer guide ring 11 together form a two-point support structure to limit the radial deflection of the plunger rod 7; Figure 8 As shown, the elastic stress transfer guide ring 11 includes an inner layer, a middle layer, and an outer layer arranged sequentially from the inside to the outside; the inner layer is slidably fitted with the plunger rod 7, the middle layer is an elastic layer, and the outer layer is fixedly connected to the inner wall of the plunger sleeve 6; the inner layer can be made of QSn4-4-2.5 tin bronze or filled with polytetrafluoroethylene material, the middle layer can be made of stainless steel metal rubber or multi-layer corrugated spring sheet, and the outer layer can be made of 42CrMo alloy steel.

[0041] When the plunger rod 7 is subjected to lateral force or bending load, the inner layer of the elastic stress transfer guide ring 11 first bears the radial force transmitted by the plunger rod 7, the middle layer undergoes elastic deformation, absorbs part of the impact load, and converts part of the bending load into a radial load before transmitting it to the outer layer. The outer layer then transmits the radial load to the plunger sleeve 6 and the oil-side cylinder head body 1. As a result, the risk of local stress concentration and uneven wear of the plunger rod 7 can be reduced.

[0042] In one specific implementation, the elastic stress transfer guide ring 11 has an axial length of 40 mm, an inner layer wall thickness of 4 mm, a middle layer wall thickness of 2 mm, and an outer layer wall thickness of 4 mm. There is a radial clearance of about 0.10 mm between the inner layer and the plunger rod 7, and the outer layer is fitted with an interference fit with the inner wall of the plunger sleeve 6, with an interference amount of 0.015 mm. When the middle layer is made of stainless steel rubber, its porosity can be about 25%, and its radial stiffness can be 900 N / mm. The above parameters can be adjusted according to the diameter of the plunger rod 7, the working pressure, and the allowable runout.

[0043] The sealing area 8 is located between the plunger rod 7 and the plunger sleeve 6, and can be located between or adjacent to the main guide ring 9 and the elastic stress transfer guide ring 11. The sealing area 8 can use multiple sealing rings, combined seals or other high-pressure resistant sealing structures to reduce hydraulic oil leakage along the gap between the plunger rod 7 and the plunger sleeve 6. The main guide ring 9 is located on the side of the sealing area 8 closer to the high-pressure oil chamber, which helps to reduce the lateral force of the plunger rod 7 acting directly on the seal, thereby reducing the risk of uneven wear in the sealing area 8.

[0044] III. Constant pressure tightening mechanism for exhaust rod to prevent loosening and leakage like Figure 4 As shown, the constant pressure anti-loosening and anti-leakage mechanism 4 of the exhaust rod is installed on the air-side cylinder head body 5; the air-side cylinder head body 5 is provided with an exhaust rod mounting hole, the exhaust rod 18 is installed in the exhaust rod mounting hole, and is threadedly connected to the air-side cylinder head body 5 through the NPT thread area 17; the NPT thread area 17 can adopt a tapered pipe thread structure, which is used to generate axial preload when the exhaust rod 18 is tightened.

[0045] The constant pressure tightening anti-loosening and anti-leakage mechanism 4 of the exhaust pressure rod includes an outlet section dynamic impedance matching section 12, a toothed sealing gasket 13, an exhaust valve 14, an inlet section dynamic impedance matching section 15, an NPT threaded collar 16, an NPT threaded area 17, and an exhaust pressure rod 18.

[0046] The intake end of the exhaust rod 18 has a cavity for accommodating the exhaust valve 14, and a sealing step for supporting the exhaust valve 14 is formed in the cavity; the exhaust valve 14 is installed in the intake end cavity of the exhaust rod 18; the NPT threaded collar 16 is located at the rear end of the exhaust valve 14 and is threadedly engaged with the internal cavity of the exhaust rod 18.

[0047] During installation, first place the first toothed sealing gasket 13 at the sealing step inside the exhaust pressure rod 18, then install the exhaust valve 14 into the air inlet cavity of the exhaust pressure rod 18, and then screw in the NPT threaded collar 16 so that the exhaust valve 14 is pressed tightly at the sealing step; through this structure, an internal compression seal is formed between the exhaust valve 14 and the exhaust pressure rod 18.

[0048] A groove extending axially can be provided on the air-side cylinder head body 5, and a second toothed sealing gasket 13 is disposed in the groove; the top end of the exhaust pressure rod 18 extends into the groove and is threadedly connected to the air-side cylinder head body 5 through the NPT thread area 17; when the exhaust pressure rod 18 is tightened, the top end of the exhaust pressure rod 18 presses against the second toothed sealing gasket 13 located in the groove, so that an external pressure seal is formed between the exhaust pressure rod 18 and the air-side cylinder head body 5.

[0049] like Figure 5 As shown, at least one sealing end face of the toothed gasket 13 is provided with multiple concentric serrated ridges; under the action of axial preload, the ridges form multiple annular sealing contact lines with the adjacent sealing surfaces; the toothed gasket 13 can be made of 316L stainless steel, or nickel-based alloys, austenitic stainless steel or other metal sealing materials can be used depending on the gas medium, operating temperature and corrosion conditions; as a specific embodiment, the sealing surface of the toothed gasket 13 is provided with 3 concentric serrated ridges, with a tooth height of 0.2 mm and a tooth pitch of 0.8 mm.

[0050] The exhaust rod 18 can be made of 316L stainless steel; in one specific embodiment, the exhaust rod 18 has a total length of 400mm and a maximum outer diameter of 65mm; when the exhaust valve 14 is pre-tightened through the NPT threaded collar 16, a pre-tightening torque of about 80N·m can be used; when the exhaust rod 18 is connected to the air-side cylinder head body 5 through the NPT threaded area 17, a pre-tightening torque of about 120N·m can be used; the above pre-tightening torque can be adjusted according to the thread specification, gasket size and working pressure.

[0051] The inlet section dynamic impedance matching section 15 is set on the inner hole of the NPT threaded collar 16, and the outlet section dynamic impedance matching section 12 is set on the inner hole of the exhaust pressure rod 18. Both the inlet section dynamic impedance matching section 15 and the outlet section dynamic impedance matching section 12 can adopt a three-section gradually changing micro-diameter pipe structure, which includes an inlet section, an intermediate micro-shrinking section and an outlet gradually expanding section. The inlet section has a normal pipe diameter, the pipe diameter of the intermediate micro-shrinking section is smaller than the pipe diameter of the inlet section, and the outlet gradually expanding section gradually expands from the intermediate micro-shrinking section to the normal pipe diameter.

[0052] Preferably, the diameter reduction ratio of the intermediate miniaturized section is 3% to 8%, and the total length of the dynamic impedance matching section is 2.5 to 3 times the corresponding pipe diameter; a smooth transition structure is adopted between the inlet section, the intermediate miniaturized section and the outlet expanding section, without steps or sharp corners.

[0053] In one specific implementation, the inlet section dynamic impedance matching section 15 is set on the inner hole of the NPT threaded collar 16, with an inlet section diameter of 30mm, an intermediate miniaturized section diameter of 28.5mm, a diameter reduction ratio of 5%, and an outlet section gradually expanding back to 30mm; the outlet section dynamic impedance matching section 12 is set on the inner hole of the exhaust pressure rod 18, with an inlet section diameter of 16mm, an intermediate miniaturized section diameter of 15.2mm, a diameter reduction ratio of 5%, and an outlet section gradually expanding back to 16mm; after processing, the inlet section dynamic impedance matching section 15 and the outlet section dynamic impedance matching section 12 can be electrochemically polished or precision polished to make the inner wall surface roughness no greater than Ra0.4μm.

[0054] During operation, high-pressure gas enters the exhaust flow channel of the exhaust rod 18 through the exhaust valve 14. Since the exhaust valve 14 is located in the internal cavity of the exhaust rod 18, an internal seal is formed between the exhaust valve 14 and the exhaust rod 18. At the same time, an external seal is formed between the exhaust rod 18 and the gas-side cylinder head body 5 through the toothed sealing gasket 13. When the high-pressure gas passes through the inlet section dynamic impedance matching section 15 and the outlet section dynamic impedance matching section 12, the flow channel cross-section gradually changes, which helps to reduce local pressure shocks and gas pulsation, thereby reducing the alternating load on the exhaust valve 14 and the exhaust rod 18.

[0055] IV. Symmetrical oblique hole oil distribution structure like Figure 6 and Figure 7 As shown, the symmetrical inclined hole oil distribution structure 3 is located on the side of the oil-side cylinder head body 1 near the diaphragm oil-side cavity and is connected to the pressurization cavity of the plunger rod 7. The symmetrical inclined hole oil distribution structure 3 includes an annular pressure equalizing groove 19, a radial pressure equalizing groove 20, an inner ring oil distribution hole 21, an outer ring oil distribution hole 22, and a radially symmetrical oil distribution channel 23. The end face of the pressurization cavity of the plunger rod 7 is provided with a central circular pressure equalizing area, the depth of which can be consistent with the depth of the annular pressure equalizing groove 19 and the radial pressure equalizing groove 20. The radial pressure equalizing groove 20 is arranged symmetrically in a cross shape and connects the central circular pressure equalizing area, the inner ring annular pressure equalizing groove 19, and the outer ring annular pressure equalizing groove 19. The inner ring oil distribution hole 21 and the outer ring oil distribution hole 22 are respectively arranged symmetrically around the axis of the plunger rod 7. The inner ring oil distribution hole 21 is connected through the inner ring annular pressure equalizing groove 19, and the outer ring oil distribution hole 22 is connected through the outer ring annular pressure equalizing groove 19.

[0056] In one specific embodiment, the depth of both the annular equalizing groove 19 and the radial equalizing groove 20 is 0.5 mm, and the groove width is adapted to the diameter of the inner ring oiling hole 21 or the outer ring oiling hole 22; for example, when the diameter of the inner ring oiling hole 21 and the outer ring oiling hole 22 is 3 mm, the width of the annular equalizing groove 19 and the radial equalizing groove 20 can be 3 mm; the radius of the central circular equalizing region can be 4 mm, and the depth can be 0.5 mm.

[0057] There are five or more sets of inner ring oil distribution holes 21, which are directly connected to the diaphragm oil side cavity. Among the inner ring oil distribution holes 21, at least two sets of holes arranged in a cross shape are inclined inward along the axial direction of the piston rod 7, and the remaining inner ring oil distribution holes 21 are inclined outward along the axial direction of the piston rod 7. The inclination angle of the inner ring oil distribution holes 21 is preferably 15° to 25°. Among them, the inwardly inclined inner ring oil distribution holes 21 are used to guide part of the hydraulic oil to the central area of ​​the diaphragm oil side cavity, and the outwardly inclined inner ring oil distribution holes 21 are used to guide part of the hydraulic oil from the middle to the outer area.

[0058] The outer ring oil distribution holes 22 are arranged in six or more groups, preferably in an even number; the outer ring oil distribution holes 22 are directly connected to the diaphragm oil side cavity and are inclined outward axially along the direction of the plunger rod 7; the inclination angle of the outer ring oil distribution holes 22 is preferably 20° to 35°; the outer ring oil distribution holes 22 are used to guide the hydraulic oil to the outer side or edge area of ​​the diaphragm oil side cavity.

[0059] The radially symmetrical oil distribution channel 23 includes a radial hole 23a formed on the circumferential surface of the booster chamber near the end face of the plunger rod 7, and a through hole 23b formed on the oil-side cylinder head body 1 and correspondingly communicating with the radial hole 23a; the radial hole 23a communicates with the annular pressure equalizing groove 19 of the outer ring, and the through hole 23b communicates with the corresponding radial hole 23a, so that the hydraulic oil in the annular pressure equalizing groove 19 of the outer ring can enter the outer region of the diaphragm oil-side chamber in sequence through the radial hole 23a and the through hole 23b; the number of radial holes 23a is preferably in the outer ring. Half the number of oil distribution holes 22 are arranged symmetrically with the outer ring oil distribution holes 22 in the circumferential direction; the through hole 23b is inclined outward along the axial direction of the piston rod 7, and the inclination angle is preferably 20° to 35°; through the above arrangement, the radial hole 23a and the through hole 23b together form a symmetrical oil distribution path, which can guide the hydraulic oil to the outer area of ​​the diaphragm oil side cavity, and can also make the reaction force generated during the radial oil discharge process cancel each other or partially cancel each other, thereby reducing the adverse effect of hydraulic oil pressure disturbance on the centering state of the piston rod 7.

[0060] The number of radially symmetrical oil distribution channels 23 is preferably half the number of outer ring oil distribution holes 22, and they are arranged symmetrically with the outer ring oil distribution holes 22 at intervals. The through hole 23b on the oil side cylinder head body 1 can be inclined outward along the axial direction of the piston rod 7, and the inclination angle can be 20° to 35°. This structure can allow hydraulic oil to enter the edge area of ​​the diaphragm oil side cavity, and can also reduce the adverse effect of the oil reaction force on the centering state of the piston rod 7 through symmetrical arrangement.

[0061] In a specific example, the inner ring oil distribution holes 21 are configured with 6 groups of 12 holes, each with a diameter of 3mm, evenly distributed on a circumference with a radius of 20mm; two groups of 4 holes are inclined inwards, and the remaining 4 groups of 8 holes are inclined outwards at an angle of 20°; the outer ring oil distribution holes 22 are configured with 8 groups of 16 holes, each with a diameter of 3mm, evenly distributed on a circumference with a radius of 33mm, and all the outer ring oil distribution holes 22 are inclined outwards at an angle of 25°; radially symmetrical oil distribution channels 23. There are 8 radial holes 23a in the middle, with a diameter of 10mm. The radial holes 23a and the outer ring oil distribution holes 22 are arranged at intervals in the circumferential direction and are connected to the annular pressure equalization groove 19 of the outer ring. The oil side cylinder head body 1 is provided with through holes 23b that are connected to each radial hole 23a. The through holes 23b are axially inclined outward along the progress direction of the plunger rod 7 with an inclination angle of 25°, which is used to guide the hydraulic oil led out through the radial holes 23a to the outer area of ​​the diaphragm oil side cavity.

[0062] When the plunger rod 7 is advanced, the hydraulic oil first enters the central circular pressure equalization area, the radial pressure equalization groove 20, and the annular pressure equalization groove 19, and undergoes pressure balancing and flow distribution before entering the diaphragm oil side cavity. Subsequently, the hydraulic oil enters the diaphragm oil side cavity through the inner ring oil distribution hole 21, the outer ring oil distribution hole 22, and the radially symmetrical oil distribution channel 23, respectively. Since the inner ring oil distribution hole 21, the outer ring oil distribution hole 22, and the radially symmetrical oil distribution channel 23 are all symmetrically arranged around the axis of the plunger rod 7, the reaction forces generated during the oil injection or discharge process can cancel each other out or partially cancel each other out, thereby reducing the adverse effects on the alignment state of the plunger rod 7.

[0063] V. Overall Machine Operation Process When the compressor starts, the plunger rod 7 begins to reciprocate within the plunger sleeve 6. At this time, the plunger rod 7 moves at a low speed, and the dynamic pressure groove unit 10 has not yet formed a stable dynamic pressure oil film. The main guiding ring 9 and the elastic stress transfer guide ring 11 mainly serve as mechanical guides. After the plunger rod 7 compresses the hydraulic oil, the hydraulic oil enters the diaphragm oil side cavity through the symmetrical inclined hole oil distribution structure 3. The annular pressure equalizing groove 19 and the radial pressure equalizing groove 20 distribute the hydraulic oil, and the inner ring oil distribution hole 21, the outer ring oil distribution hole 22 and the radially symmetrical oil distribution channel 23 guide the hydraulic oil to different areas of the diaphragm oil side cavity, so that the oil side pressure is gradually established.

[0064] When the compressor is running normally, the reciprocating speed of the plunger rod 7 increases, and the herringbone bidirectional spiral groove 24 in the dynamic pressure groove unit 10 pumps the oil between the plunger rod 7 and the plunger sleeve 6, forming a dynamic pressure oil film on the outer periphery of the plunger rod 7. This oil film can reduce the direct contact between the plunger rod 7 and the plunger sleeve 6. At the same time, the main directional ring 9 and the elastic stress transfer guide ring 11 continue to provide radial constraints, and the symmetrical oblique hole oil distribution structure 3 continues to supply oil evenly to the diaphragm oil side cavity.

[0065] When the compressed high-pressure gas is discharged through the exhaust valve 14, the exhaust valve 14 is axially pressed inside the exhaust rod 18 by the NPT threaded collar 16, and the exhaust rod 18 is pressed and connected to the gas-side cylinder head body 5 through the NPT threaded area 17; the toothed sealing gasket 13 forms a seal between the exhaust valve 14 and the exhaust rod 18, and between the exhaust rod 18 and the gas-side cylinder head body 5; when the high-pressure gas passes through the inlet section dynamic impedance matching section 15 and the outlet section dynamic impedance matching section 12, the gas impact and pressure pulsation are mitigated to a certain extent due to the gradual change of the flow channel cross section.

[0066] When the compressor experiences pressure fluctuations, hydraulic instantaneous overload, or frequent start-stop conditions, the plunger rod 7 may bear large lateral forces or bending loads. At this time, the middle layer of the elastic stress transfer guide ring 11 undergoes elastic deformation, absorbing part of the impact energy and converting part of the bending load into a radial load that is transmitted to the plunger sleeve 6 and the oil-side cylinder head body 1. Meanwhile, the symmetrical oblique hole oil distribution structure 3 reduces oil pressure disturbance through symmetrically arranged hole systems and pressure equalization grooves, and the constant pressure clamping anti-loosening and anti-leakage mechanism 4 of the exhaust pressure rod maintains the sealing state of the exhaust end through internal clamping and external clamping structures.

[0067] VI. Specific Prototype Implementation Examples In a specific prototype, the above structure is applied to a 70MPa high-pressure hydrogen diaphragm compressor. In this prototype, the plunger rod 7 is made of 38CrMoAlA alloy steel, with a nitrided surface, a diameter of 60mm, and a total length of 600mm. The plunger sleeve 6 is made of 42CrMo alloy steel, with a precision-machined inner hole and a surface roughness of no more than Ra0.4μm. The dynamic pressure groove unit 10 adopts a herringbone bidirectional spiral groove 24 with a spiral angle of 20°, a groove depth of 0.25mm, a groove width of 1.0mm, 4 spiral groove heads, and an axial length of 40mm. The main guide ring 9 is made of QSn4-4-2.5 tin bronze, with an axial length of 25mm and a wall thickness of 4mm. The elastic stress transfer guide ring 11 has an axial length of 40mm, with an inner layer of QSn4-4-2.5 tin bronze, a middle layer of stainless steel metal rubber, and an outer layer of 42CrMo alloy steel.

[0068] The exhaust rod 18 is made of 316L stainless steel, with a total length of 400mm and a maximum outer diameter of 65mm. The exhaust valve 14 is built into the intake end cavity of the exhaust rod 18. A 316L toothed sealing gasket 13 is provided between the exhaust valve 14 and the exhaust rod 18. The toothed sealing gasket 13 has three concentric sawtooth ridges with a tooth height of 0.2mm and a tooth pitch of 0.8mm. The exhaust valve 14 is pressed by an NPT threaded collar 16 with a preload torque of 80N·m. The exhaust rod 18 is connected to the air-side cylinder head body 5 through an NPT threaded area 17 with a preload torque of 120N·m.

[0069] The inlet section dynamic impedance matching section 15 is set on the inner hole of the NPT threaded collar 16. Its inlet section diameter is 30mm, the middle micro-section diameter is 28.5mm, the diameter reduction ratio is 5%, and the outlet section gradually expands back to 30mm. The outlet section dynamic impedance matching section 12 is set on the inner hole of the exhaust pressure rod 18. Its inlet section diameter is 16mm, the middle micro-section diameter is 15.2mm, the diameter reduction ratio is 5%, and the outlet section gradually expands back to 16mm.

[0070] In the symmetrical inclined hole oil distribution structure 3, the inner ring oil distribution holes 21 consist of 6 groups of 12 holes with a diameter of 3mm, evenly distributed on a circumference with a radius of 20mm; two groups of 4 holes are inclined inward, and the remaining 4 groups of 8 holes are inclined outward, with an inclination angle of 20°; the outer ring oil distribution holes 22 consist of 8 groups of 16 holes with a diameter of 3mm, evenly distributed on a circumference with a radius of 33mm, and all the outer ring oil distribution holes 22 are inclined outward, with an inclination angle of 25°; the annular pressure equalizing groove 19 and the radial pressure equalizing groove 20 are 3mm wide and 0.5mm deep; the radial symmetrical oil distribution channels 23 are set to 8 and are connected to the annular pressure equalizing groove 19 of the outer ring.

[0071] In the aforementioned prototype test, the 70MPa high-pressure hydrogen diaphragm compressor underwent a 500-hour operation test. After the test, no obvious wear marks were observed on the surface of the plunger rod 7, and the wear on the inner surfaces of the main directional ring 9 and the elastic stress transfer guide ring 11 was no more than 0.01mm. After 100 consecutive start-stop cycles, the preload of the exhaust pressure rod 18 decreased by no more than 2%. Under pressure fluctuation conditions, the exhaust pressure rod 18 did not show obvious loosening, and no obvious leakage was found at the seal. The above test results indicate that the structure can meet the usage requirements of the high-pressure gas diaphragm compressor under start-up, normal operation, and pressure fluctuation conditions.

[0072] VII. Alternative Implementation Methods In other embodiments, the plunger rod 7 may be a smooth rod of constant diameter, a rod with a partially variable diameter, or other structures suitable for high-pressure reciprocating motion; the material of the plunger rod 7 is not limited to 38CrMoAlA, but may also be other alloy steels that meet the requirements of strength, wear resistance and gas medium adaptability; the plunger sleeve 6 may also be made of other high-strength wear-resistant alloy materials.

[0073] The dynamic pressure groove unit 10 is not limited to a set of herringbone bidirectional spiral grooves 24, but can also be configured with multiple sets of herringbone bidirectional spiral grooves 24 arranged axially according to the diameter of the plunger rod 7 and the reciprocating speed. When the compressor size is small, the number of spiral groove heads, groove width and axial length can be reduced accordingly. When the compressor size is large, the number of spiral groove heads and axial length can be increased accordingly.

[0074] The middle layer of the elastic stress transfer guide ring 11 can be made of stainless steel metal rubber, or it can be made of multi-layer corrugated spring sheet, annular elastic support sheet or other fatigue-resistant elastic element; as long as it can undergo elastic deformation when the plunger rod 7 is subjected to lateral force and transfer part of the load to the plunger sleeve 6, it can be used as an alternative embodiment of the present invention.

[0075] The material of the toothed gasket 13 is not limited to 316L stainless steel. Nickel-based alloys, austenitic stainless steel or other metal sealing materials can also be selected according to the corrosiveness, temperature and pressure of the compressed gas. The number of serrated ridges on the toothed gasket 13 can be 2, 3, 4 or more. The tooth height and tooth pitch can be adjusted according to the sealing pressure and sealing surface size.

[0076] The dimensions of the inlet section dynamic impedance matching section 15 and the outlet section dynamic impedance matching section 12 can be adjusted according to the exhaust pipe diameter, gas medium and pressure level; the diameter reduction ratio of the intermediate miniaturized section is preferably 3% to 8%, and the total length of the dynamic impedance matching section is preferably 2.5 to 3 times the corresponding pipe diameter.

[0077] The number, diameter, circumferential radius, and inclination angle of the inner ring oil distribution holes 21 and the outer ring oil distribution holes 22 in the symmetrical inclined hole oil distribution structure 3 can be determined according to the diaphragm diameter, oil side cavity volume, hydraulic oil flow rate, and plunger rod 7 diameter; the inner ring oil distribution holes 21 can be set to 5, 6, 8 or more groups, and the outer ring oil distribution holes 22 can be set to 6, 8, 10 or more groups; the number of radially symmetrical oil distribution channels 23 can be matched with the number of outer ring oil distribution holes 22, and the arrangement should be circumferentially symmetrical.

[0078] The above embodiments illustrate the main structure, assembly method and working process of the present invention; those skilled in the art can make conventional selections and adjustments to the size and materials of each component according to the pressure level, displacement, gas medium and installation space of the specific compressor. As long as it still adopts the combination relationship of the composite support and friction reduction structure 2, the symmetrical inclined hole oil distribution structure 3 and the constant pressure tightening anti-loosening and anti-leakage mechanism 4 of the exhaust pressure rod of the present invention, it belongs to the equivalent embodiments of the technical solution of the present invention.

Claims

1. A full-condition anti-breakage, anti-loosening, and anti-leakage structure for a high-pressure gas diaphragm compressor, comprising an oil-side cylinder head body (1), a gas-side cylinder head body (5), a composite support and anti-friction structure (2), a symmetrical oblique hole oil distribution structure (3), and a constant pressure tightening anti-loosening and anti-leakage mechanism for the exhaust pressure rod (4), characterized in that: The oil-side cylinder head body (1) and the air-side cylinder head body (5) are arranged opposite to each other. The composite support and anti-friction structure (2) is installed on the oil-side cylinder head body (1). The symmetrical oblique hole oil distribution structure (3) is set on the side of the oil-side cylinder head body (1) near the diaphragm oil-side cavity. The constant pressure tightening anti-loosening and anti-leakage mechanism (4) of the exhaust pressure rod is installed on the air-side cylinder head body (5). The composite support and anti-friction structure (2) includes a plunger sleeve (6), a plunger rod (7), a sealing area (8), a main guide ring (9), and a dynamic pressure groove. Unit (10) and elastic stress transfer guide ring (11), plunger rod (7) passes through plunger sleeve (6) and can reciprocate along the axial direction of plunger sleeve (6); dynamic pressure groove unit (10) is set on the outer circumferential surface of plunger rod (7) near the high pressure oil chamber, main guide ring (9) is set between plunger rod (7) and plunger sleeve (6) and is located on the side of sealing area (8) near the high pressure oil chamber, elastic stress transfer guide ring (11) is set on the side of plunger sleeve (6) away from the high pressure oil chamber; The symmetrical inclined hole oil distribution structure (3) is connected to the pressurization cavity of the plunger rod (7) and includes an annular pressure equalization groove (19), a radial pressure equalization groove (20), an inner ring oil distribution hole (21), an outer ring oil distribution hole (22) and a radially symmetrical oil distribution channel (23). The inner ring oil distribution hole (21) and the outer ring oil distribution hole (22) are arranged symmetrically around the axis of the plunger rod (7). The inner ring oil distribution hole (21) and the outer ring oil distribution hole (22) are connected through the corresponding annular pressure equalization groove (19). The radial pressure equalization groove (20) is connected to the annular pressure equalization groove (19). The radially symmetrical oil distribution channel (23) is connected to the annular pressure equalization groove (19) and / or the outer ring oil distribution hole (22). The constant pressure anti-loosening and anti-leakage mechanism (4) of the exhaust rod is installed in the mounting hole of the air-side cylinder head body (5) and includes an outlet section dynamic impedance matching section (12), a toothed gasket (13), an exhaust valve (14), an inlet section dynamic impedance matching section (15), an NPT threaded collar (16), an NPT threaded area (17) and an exhaust rod (18). The exhaust rod (18) is threadedly connected to the air-side cylinder head body (5) through the NPT threaded area (17). The exhaust valve (14) is set in the inlet end cavity of the exhaust rod (18). The NPT threaded collar (16) is threadedly engaged with the internal cavity of the exhaust rod (18) and is used to apply axial preload to the exhaust valve (14). The toothed gasket (13) is respectively set between the exhaust valve (14) and the exhaust rod (18) and between the exhaust rod (18) and the air-side cylinder head body (5).

2. The anti-breakage, anti-loosening, and anti-leakage structure for a high-pressure gas diaphragm compressor under all operating conditions as described in claim 1, characterized in that: The oil-side cylinder head body (1) is provided with a plunger mounting hole (25) extending along the plunger rod axially. The plunger sleeve (6) is fixedly installed in the plunger mounting hole (25) of the oil-side cylinder head body (1). The inner hole of the plunger sleeve (6) is coaxially arranged with the plunger rod (7). The end of the plunger rod (7) near the high-pressure oil chamber is arranged towards the symmetrical inclined hole oil distribution structure (3), so that when the plunger rod (7) reciprocates, it can send hydraulic oil to the symmetrical inclined hole oil distribution structure (3).

3. The anti-breakage, anti-loosening, and anti-leakage structure for a high-pressure gas diaphragm compressor under all operating conditions as described in claim 1, characterized in that: The dynamic pressure groove unit (10), the main guide ring (9), the sealing area (8) and the elastic stress transfer guide ring (11) are arranged sequentially along the axial direction of the plunger rod (7). The main guide ring (9) and the elastic stress transfer guide ring (11) are spaced apart along the axial direction of the plunger rod (7) to form a two-point support structure between the plunger rod (7) and the plunger sleeve (6). The dynamic pressure groove unit (10) includes at least one set of herringbone bidirectional spiral grooves (24), the herringbone bidirectional spiral grooves (24) include a first spiral groove segment and a second spiral groove segment, the first spiral groove segment and the second spiral groove segment have opposite spiral directions and intersect in the axial middle region of the plunger rod (7).

4. The anti-breakage, anti-loosening, and anti-leakage structure for a high-pressure gas diaphragm compressor under all operating conditions as described in claim 3, characterized in that: The herringbone bidirectional spiral groove (24) has a spiral angle of 15° to 25°, a groove depth of 0.2 mm to 0.3 mm, a groove width of 0.8 mm to 1.2 mm, and a spiral groove head of 4 to 6. The axial length of the herringbone bidirectional spiral groove (24) on the outer circumference of the plunger rod (7) is 30 mm to 50 mm.

5. The anti-breakage, anti-loosening, and anti-leakage structure for a high-pressure gas diaphragm compressor under all operating conditions as described in claim 1, characterized in that: The elastic stress transfer guide ring (11) includes an inner layer, a middle layer and an outer layer arranged sequentially from the inside to the outside; the inner layer is in sliding fit with the plunger rod (7); the middle layer is an elastic layer, which is used to generate elastic deformation when the plunger rod (7) is subjected to lateral force, and to convert at least part of the bending load on the plunger rod (7) into radial load; the outer layer is fixedly connected to the inner wall of the plunger sleeve (6) and is used to transfer the radial load to the plunger sleeve (6).

6. The anti-breakage, anti-loosening, and anti-leakage structure for a high-pressure gas diaphragm compressor under all operating conditions as described in claim 5, characterized in that: The main guide ring (9) is a QSn4-4-2.5 tin bronze guide ring or a polytetrafluoroethylene-filled guide ring; the inner layer of the elastic stress transfer guide ring (11) is a QSn4-4-2.5 tin bronze layer or a polytetrafluoroethylene-filled layer, the middle layer is a stainless steel metal rubber layer or a multi-layer corrugated spring sheet layer, and the outer layer is a 42CrMo alloy steel layer.

7. The anti-breakage, anti-loosening, and anti-leakage structure for a high-pressure gas diaphragm compressor under all operating conditions as described in claim 1, characterized in that: The air intake end of the exhaust rod (18) is provided with a cavity for accommodating the exhaust valve (14) and a sealing step for supporting the exhaust valve (14). The exhaust valve (14) is pressed against the sealing step by an NPT threaded collar (16). The toothed gasket (13) includes a first toothed gasket and a second toothed gasket. The first toothed gasket is disposed between the exhaust valve (14) and the exhaust rod (18), and the second toothed gasket is disposed between the exhaust rod (18) and the cylinder head body (5). The toothed gasket (13) is a 316L stainless steel toothed metal gasket, and the sealing surface of the toothed gasket (13) is provided with multiple concentric sawtooth ridges.

8. The anti-breakage, anti-loosening, and anti-leakage structure for a high-pressure gas diaphragm compressor under all operating conditions as described in claim 7, characterized in that: The inlet section dynamic impedance matching section (15) is set on the inner hole of the NPT threaded collar (16), and the outlet section dynamic impedance matching section (12) is set on the inner hole of the exhaust pressure rod (18). Both the inlet section dynamic impedance matching section (15) and the outlet section dynamic impedance matching section (12) are three-section gradually changing micro-diameter tube structures. The three-section gradually changing micro-diameter tube structure includes an inlet section, an intermediate micro-shrinking section and an outlet gradually expanding section. The diameter reduction ratio of the intermediate micro-shrinking section is 3% to 8%. The total length of the inlet section dynamic impedance matching section (15) and the outlet section dynamic impedance matching section (12) is 2.5 to 3 times the corresponding tube diameter, and its inner wall is a smooth transition structure.

9. The anti-breakage, anti-loosening, and anti-leakage structure for a high-pressure gas diaphragm compressor under all operating conditions according to claim 1, characterized in that: The pressure chamber end face of the plunger rod (7) is provided with a central circular pressure equalization area, and the radial pressure equalization grooves (20) are arranged in a cross shape and connected to the central circular pressure equalization area, the inner ring pressure equalization groove (19) and the outer ring pressure equalization groove (19). There are five or more sets of inner ring oil distribution holes (21), which are directly connected to the oil side cavity of the diaphragm. At least two sets of inner ring oil distribution holes (21) arranged in a cross shape are inclined inward along the direction of the plunger rod (7), and the remaining inner ring oil distribution holes (21) are inclined outward along the direction of the plunger rod (7). The inclination angle of the inner ring oil distribution holes (21) is 15° to 25°.

10. The anti-breakage, anti-loosening, and anti-leakage structure for a high-pressure gas diaphragm compressor under all operating conditions according to claim 9, characterized in that: The number of outer ring oil distribution holes (22) is six or more and is even. The outer ring oil distribution holes (22) are directly connected to the diaphragm oil side cavity and are axially inclined outward along the direction of the plunger rod (7). The inclination angle of the outer ring oil distribution holes (22) is 20° to 35°. The radially symmetrical oil distribution channel (23) includes a radial hole (23a) formed on the circumferential surface of the pressurization chamber near the end face of the piston rod (7), and a through hole (23b) formed on the oil-side cylinder head body (1) and correspondingly connected to the radial hole (23a); the radial hole (23a) is connected to the annular equalizing groove (19) of the outer ring, and the through hole (23b) is used to guide the hydraulic oil led out through the radial hole (23a) to the outer region of the diaphragm oil-side chamber; the number of radial holes (23a) is half the number of outer ring oil distribution holes (22), and the radial holes (23a) and the outer ring oil distribution holes (22) are symmetrically arranged at intervals in the circumferential direction; the through hole (23b) is axially inclined outward along the progress direction of the piston rod (7), and the inclination angle is 20° to 35°.

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