Dynamic sealing element of compressor cylinder
Through a three-layer gradient structure sealing jacket and optimized design, the problems of long life, high temperature and pressure resistance and low leakage of cylinder dynamic seals are solved, achieving higher stability and service life.
Patent Information
- Application Number
- CN202511371152.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-24
- Publication Date
- 2026-01-02
AI Technical Summary
Existing cylinder dynamic seal structures cannot simultaneously meet the requirements of long service life, high temperature and pressure resistance, and low leakage.
The sealing jacket adopts a three-layer gradient structure. The outer layer is graphene or graphite and molybdenum disulfide, the middle layer is carbon fiber or glass fiber and metal powder, and the inner layer is carbon fiber, PEEK or PI. It is made by cold pressing and combined with interference fit and protrusion design to optimize the fit between the sealing jacket and the retaining ring.
It improves the temperature resistance of the sealing element, enhances heat dissipation, extends service life, reduces leakage rate, and ensures the stability and reliability of the cylinder dynamic seal.
Smart Images
Figure CN121251815A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of compressor seal. More particularly, the present application relates to a compressor cylinder dynamic sealing element. BACKGROUND
[0002] In the storage, transportation and application of natural gas, hydrogen, carbon dioxide and other gases, compressors are essential equipment, and the performance of the gas pressurizing cylinder as the core component of the compressor directly affects the working efficiency and stability of the entire compressor. Among them, the cylinder dynamic sealing technology is the key to ensuring the safety and reliability of the compressor equipment.
[0003] The core of the cylinder dynamic sealing technology is to achieve long service life, high temperature pressure resistance and low leakage. Long service life means that the sealing product can maintain stable performance during long-term use, reduce replacement frequency and reduce cost. High pressure resistance requires the product to withstand extremely high pressure to ensure the safe transportation and storage of gas in a high pressure environment. Low leakage ensures that the gas does not leak, avoiding energy waste and safety hazards.
[0004] Currently, the commonly used structure of the cylinder dynamic seal is a jacket, which can be selected to make the cylinder dynamic seal have certain performance, but it cannot meet the requirements of long service life, high temperature pressure resistance and low leakage of the cylinder dynamic sealing technology at the same time. SUMMARY
[0005] Another object of the present application is to provide a compressor cylinder dynamic sealing element that can meet the requirements of long service life, high temperature pressure resistance and low leakage at the same time.
[0006] In order to achieve these objects and other advantages according to the present application, a compressor cylinder dynamic sealing element is provided, which is installed in a compressor cylinder dynamic sealing groove and includes a seal jacket and an elastic body. The upper part of the seal jacket is provided with a groove, and the elastic body is clamped in the groove. The bottom of the seal jacket is tightly attached to the bottom of the seal jacket. The top surface of the upper part of the seal jacket and the bottom of the seal jacket are gap-fitted with the cylinder body of the compressor cylinder. The two sides of the top surface of the seal jacket are interference-fitted with the cylinder body of the compressor cylinder. The seal jacket is a three-layer gradient structure, and any layer is made by mixing PTFE base material and modified filler and cold pressing. The addition ratio of the three layers of modified filler increases layer by layer from the outside to the inside.
[0007] Preferably, the modified filler of the outer layer of the seal jacket is one or more of graphene, graphite and molybdenum disulfide. The modified filler of the middle layer is one or more of carbon fiber, glass fiber and metal powder. The modified filler of the inner layer is one or more of carbon fiber, glass fiber, PEEK or PI. The filling ratio of the modified filler of each layer is not more than 20%.
[0008] Preferably, the single-side interference amount of the sealing jacket to the compressor cylinder block is 0.2-1.2 mm; the gap between the top surface of the upper part of the sealing jacket, the bottom of the check ring and the compressor cylinder block is 0.05-0.15 mm.
[0009] Preferably, the ratio of the height dimension of the sealing jacket to the height dimension of the lower part thereof is 2:1-3:1; the ratio of the height dimension of the sealing jacket to the height dimension of the check ring is 2:1-5:1.
[0010] Preferably, the inner side wall of the top part of the groove is provided with a protrusion for limiting the elastic body in the groove.
[0011] Preferably, the elastic body is a spring or an O-shaped rubber ring.
[0012] Preferably, the molecular weight of the PTFE base material raw material is greater than 8 million.
[0013] Preferably, the check ring is made of PEEK or PI hard polymer base material.
[0014] Preferably, the three-layer structure of the sealing jacket is filled and cold-pressed layer by layer from outside to inside or from inside to outside.
[0015] The present application at least includes the following beneficial effects: the present application optimizes and improves the structure and material of the universal seal, sets the sealing jacket into a three-layer structure, adds different heat-conducting modified fillers in the three-layer structure, so that the sealing jacket has a temperature resistance of up to 260°C and good heat-conducting performance, can avoid the accumulation of heat in the sealing element during reciprocating motion, improve the heat dissipation capacity of the sealing element, improve the high-temperature dimensional stability of the sealing element, improve the sealing life, at the same time, solve the problems of wear resistance and dimensional stability, and guarantee the stability and service life of the cylinder dynamic seal.
[0016] Other advantages, objects and features of the present application will be partly embodied in the following description, and partly understood by those skilled in the art through research and practice of the present application. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 Structure schematic view of the universal seal with the elastic body being a spring according to the present application; Figure 2 Structure schematic view of the universal seal with the elastic body being an O-shaped rubber ring according to the present application; Figure 1 Assembly structure schematic view of the compressor cylinder dynamic sealing element according to the present application; Figure 3 Structure schematic view of the universal seal with the elastic body being a spring according to the present application; Figure 4 Assembly structure schematic view of the compressor cylinder dynamic sealing element according to the present application; Figure 3A schematic diagram of the assembly structure of the dynamic sealing element of the compressor cylinder; Figure 5 This is a schematic diagram of the three-layer structure of the sealing jacket of the present invention; Explanation of reference numerals in the instruction manual: 1. Cylinder body, 2. Sealing groove, 3. Piston, 4. Sealing jacket, 41. Groove, 42. Protrusion, 5. Spring, 6. Retaining ring, 7. O-ring. Detailed Implementation
[0018] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.
[0019] It should be noted that in the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0020] like Figures 1-5 As shown, the present invention provides a dynamic sealing element for a compressor cylinder, suitable for reciprocating dynamic seals with pressures of 5~90MPa and temperatures of -60~260°C. It is installed in the dynamic sealing groove 2 of the compressor cylinder and includes a plug seal and a retaining ring 6. The plug seal includes a sealing jacket 4 and an elastic body. The upper part of the sealing jacket 4 has a groove 41, and the elastic body is engaged in the groove 41. The retaining ring 6 is tightly attached to the bottom of the sealing jacket 4. The top surface of the upper part of the sealing jacket 4 and the bottom of the retaining ring 6 are clearance-fitted with the cylinder body 1 of the compressor cylinder, and the two sides of the top surface of the sealing jacket 4 are interference-fitted with the cylinder body 1 of the compressor cylinder. The sealing jacket 4 has a three-layer gradient structure. Each layer is made by cold pressing a mixture of PTFE substrate and modified filler. The addition ratio of the three layers of modified filler increases from the outside to the inside. The modified filler of the outer layer of the sealing jacket 4 is one or more of graphene, graphite, and molybdenum disulfide; the modified filler of the middle layer is one or more of carbon fiber, glass fiber, and metal powder; the modified filler of the inner layer is one or more of carbon fiber, glass fiber, PEEK, or PI; and the filling ratio of each layer of modified filler is no more than 20%.
[0021] In the above technical solutions, such as Figure 2 , Figure 4 The dynamic sealing element is assembled in the dynamic sealing groove 2 formed by the compressor cylinder and piston 3, such as... Figure 1 ,Figure 3 As shown, the dynamic sealing element includes a generic seal and a retainer 6, the generic seal is composed of a sealing jacket 4 and an elastomer clamped in the sealing jacket 4, and the retainer 6 is in close contact with the sealing jacket 4, the outer wall of the dynamic sealing element is in close contact with the compressor cylinder during the reciprocating movement of the compressor cylinder, so as to realize the sealing effect, as shown in the figure Figure 5 As shown, the sealing jacket 4 has a three-layer gradient structure, the three-layer gradient structure is obtained by filling the cold-pressed PTFE base material and modified filler, the PTFE base material of each layer is modified by different modified fillers, so that the hardness, self-lubricity, wear resistance and creep resistance of the sealing jacket 4 from the outside to the inside present gradient changes, wherein the modified filler of the outer layer is one or more of graphene, graphite and molybdenum disulfide, so that the outer layer has excellent self-lubricity, the intermediate layer is one or more of carbon fiber, glass fiber and metal powder, so that the intermediate layer has excellent wear resistance, and the inner layer is one or more of carbon fiber, glass fiber, PEEK or PI, so that the inner layer has excellent creep resistance, the smaller the particle size of each layer of modified filler, the smaller the corresponding proportion, and the proportion of each layer of modified filler is not more than 20%; by optimizing and improving the structure and material of the generic seal, the sealing jacket 4 is arranged in a three-layer structure, and different heat-conducting modified fillers are added in the three-layer structure, so that the sealing jacket 4 has a high temperature resistance of 260°C and good heat conductivity, heat aggregation in the dynamic sealing element during reciprocating movement can be avoided, the heat dissipation capacity of the dynamic sealing element is improved, the high-temperature dimensional stability of the dynamic sealing element is improved, the sealing life is improved, the wear resistance and dimensional stability problems are solved, and the stability and service life of the cylinder dynamic seal are ensured.
[0022] In another technical solution, the single-side interference amount of the sealing jacket 4 and the compressor cylinder body 1 is 0.2-1.2mm; the gap between the top surface of the upper part of the sealing jacket 4 and the bottom of the retainer 6 and the compressor cylinder body 1 is 0.05-0.15mm; the ratio of the height size of the sealing jacket 4 to the height size of the lower part of the sealing jacket 4 is 2:1-3:1; and the ratio of the height size of the sealing jacket 4 to the height size of the retainer 6 is 2:1-5:1.
[0023] In this technical solution, by designing the height size ratio of the sealing jacket 4 as a whole, the lower part of the sealing jacket 4 and the retainer 6, and the engagement gap of the sealing jacket 4, the retainer 6 and the cylinder body 1, the sealing leakage rate can be reduced, the sealing effect can be improved, the energy waste and potential safety hazards can be reduced, at the same time, the stress can be more concentrated on the retainer 6, the stress concentration of the generic seal can be reduced, the wear of the sealing jacket 4 can be reduced, and the service life can be prolonged.
[0024] In another technical solution, the inner side wall of the top of the groove 41 is provided with a protrusion 42, and the protrusion 42 is used to limit the elastomer in the groove 41.
[0025] In the above technical solution, the elastic member is clamped in the groove 41 by the protrusion 42, which can avoid the elastic body from being separated from the groove 41 due to vibration caused by the reciprocating motion of the compressor cylinder, thereby reducing the sealing stability; the protrusion is integrally formed with the sealing jacket 4.
[0026] In another technical solution, the elastic body is a spring 5 or an O-shaped rubber ring 7.
[0027] In the above technical solution, the spring 5 can be a spring 5 with a V-shaped or U-shaped cross section selected according to the pressure, or a spiral spring 5, and the material of the spring 5 can be selected according to the gas medium; the O-shaped rubber ring 7 can be selected according to the pressure, temperature and medium, and the specific selection is as follows: for low pressure (0-45 MPa), the elastic body is selected to be a spring 5 with a V-shaped or U-shaped cross section or an O-shaped rubber ring 7 with a smaller hardness; for high pressure (45-90 MPa), the elastic body is selected to be a spiral spring 5 or an O-shaped rubber ring 7 with a larger hardness.
[0028] In another technical solution, the molecular weight of the PTFE base material raw material is greater than 8 million.
[0029] In the above technical solution, the molecular weight of the PTFE base material raw material is greater than 8 million, which can improve the pressure resistance and creep resistance of the sealing jacket 4.
[0030] In another technical solution, the retainer 6 is made of a PEEK or PI hard polymer base material.
[0031] In the present technical solution, the retainer 6 is made of a PEEK or PI hard polymer base material, which can ensure the hardness and pressure resistance of the retainer 6, and the retainer 6 is used to prevent the seal from being engaged. In high-pressure working conditions, when the cooperation gap between the piston 3 and the cylinder body 1 is small, the retainer 6 in a is selected; when the cooperation gap is large, the double retainer 6 cooperation design in b is used. Figure 3 Figure 3
[0032] In another technical solution, the three-layer structure of the sealing jacket 4 is filled and cold-pressed layer by layer from the outside to the inside or from the inside to the outside.
[0033] In the above technical solution, the three-layer structure is obtained by the method of filling and cold-pressing layer by layer, which can first fill the outer layer of powder in the mold, cold-press, then fill the middle layer of powder, cold-press, then fill the inner layer of powder, cold-press, and finally sinter together to obtain the sealing jacket 4; or the sealing jacket 4 can be obtained by filling, cold-pressing and sintering from the inner layer to the outer layer according to the above steps.
[0034] <Example 1> A compressor cylinder dynamic sealing element is composed of a sealing jacket 4, a spring 5 and a retaining ring 6, the spring 5 is installed in a groove 41 of the sealing jacket 4, the spring 5 is made of hydrogen embrittlement resistant metal such as 316L or A286, the retaining ring 6 is made of PI, the height ratio of the sealing jacket 4 to the retaining ring 6 is 2.5:1, the height ratio of the sealing jacket 4 to the lower part of the sealing jacket 4 (the part without the groove 41) is 2.2:1; the sealing jacket 4 is a three-layer gradient structure, each layer is a composite layer formed by cold pressing the mixture of PTFE base material with a molecular weight of 10 million and modified filler, the modified filler of the outer layer of the sealing jacket 4 is graphene and molybdenum disulfide, the modified filler of the middle layer is carbon fiber and PI, the modified filler of the inner layer is molybdenum disulfide and PI, the proportion of the modified filler is 5% for the outer layer, 15% for the middle layer and 15% for the inner layer, the thickness ratio of the outer layer, the middle layer and the inner layer is 1:2:2, the three-layer gradient structure is filled and cold-pressed layer by layer in the order from the inner layer to the outer layer, and finally sintered together to obtain the sealing jacket 4; the retaining ring 6 is installed at the bottom of the sealing jacket 4 to obtain the compressor cylinder dynamic sealing element, wherein the single-side interference amount of the sealing jacket 4 to the cylinder body 1 is 0.4mm, the fit clearance of the sealing jacket 4 to the cylinder body 1 and the fit clearance of the retaining ring 6 to the cylinder body 1 are both 0.08mm.
[0035] <Comparative Example 1> A compressor cylinder dynamic sealing element is a PTEE jacket.
[0036] The dynamic sealing elements of Example 1 and Comparative Example 1 are respectively applied to the reciprocating operation of a compressor cylinder with a working pressure of 90MPa, a maximum temperature of 200°C, a reciprocating linear velocity of 0.1m / s and hydrogen as the medium, and comparison is made in terms of heat conduction performance, dynamic friction performance, wear resistance, stability, sealing performance, expected service life and the like, and the comparison results are shown in Table 1: Table 1
[0037] As shown in Table 1, the heat conduction coefficient, dynamic friction coefficient, specific wear amount, creep resistance, leakage rate and expected service life of Example 1 of the application are all better than those of Comparative Example 1, and the compressor cylinder dynamic sealing element of the application can simultaneously meet the requirements of long service life, high temperature pressure resistance and low leakage.
[0038] Although the embodiments of the application have been disclosed as above, they are not limited to the application listed in the specification and embodiments, and can be fully applied to various fields suitable for the application, and additional modifications can be easily realized by those skilled in the art, and therefore the application is not limited to specific details and the figures shown and described herein, without departing from the general concept defined by the claims and the equivalent scope.
Claims
1. A dynamic sealing element for a compressor cylinder, installed within a dynamic sealing groove of the compressor cylinder, comprising a plug seal and a retaining ring, characterized in that, The sealing sleeve includes a sealing jacket and an elastomer. The upper part of the sealing jacket has a groove, the elastomer is inserted into the groove, the retaining ring is tightly attached to the bottom of the sealing jacket, the top surface of the upper part of the sealing jacket and the bottom of the retaining ring are clearance fit with the cylinder body of the compressor cylinder, and the two sides of the top surface of the sealing jacket are interference fit with the cylinder body of the compressor cylinder. The sealing jacket has a three-layer gradient structure. Each layer is made by cold pressing a mixture of PTFE substrate and modified filler. The proportion of modified filler added in the three layers increases from the outside to the inside.
2. The compressor cylinder dynamic sealing element as described in claim 1, characterized in that, The modified filler of the outer layer of the sealing jacket is one or more of graphene, graphite, and molybdenum disulfide; the modified filler of the middle layer is one or more of carbon fiber, glass fiber, and metal powder; the modified filler of the inner layer is one or more of carbon fiber, glass fiber, PEEK, or PI; the filling ratio of each layer of modified filler is no more than 20%.
3. The compressor cylinder dynamic sealing element as described in claim 1, characterized in that, The interference fit between the sealing jacket and the compressor cylinder body on one side is 0.2~1.2mm; the gap between the top surface of the upper part of the sealing jacket, the bottom of the retaining ring and the compressor cylinder body is 0.05~0.15mm.
4. The compressor cylinder dynamic sealing element as described in claim 1, characterized in that, The ratio of the height dimension of the sealing jacket to its lower height dimension is 2:1 to 3:1; the ratio of the height dimension of the sealing jacket to the height dimension of the retaining ring is 2:1 to 5:
1.
5. The compressor cylinder dynamic sealing element as described in claim 1, characterized in that, The inner wall of the top of the groove is provided with a protrusion, which is used to confine the elastomer within the groove.
6. The compressor cylinder dynamic sealing element as described in claim 1, characterized in that, The elastomer is a spring or an O-ring.
7. The compressor cylinder dynamic sealing element as described in claim 1, characterized in that, The molecular weight of the PTFE substrate raw material is greater than 8 million.
8. The compressor cylinder dynamic sealing element as described in claim 1, characterized in that, The retaining ring is made of PEEK or PI rigid polymer substrate.
9. The compressor cylinder dynamic sealing element as described in claim 1, characterized in that, The three-layer structure of the sealing jacket is formed by cold pressing and filling layer by layer from the outside to the inside or from the inside to the outside.