Compensation type dynamic seal piston structure

Abstract

The utility model relates to a piston dynamic sealing structure, and provides a compensation type dynamic sealing piston structure in order to solve the problems that the service lives of sealing pieces at different positions of an existing piston dynamic sealing structure are not consistent, the tensioning force of the sealing pieces is not uniform and the like, the compensation type dynamic sealing piston structure comprises a piston body, and a plurality of annular grooves are evenly formed in the outer side circumference of the piston body from top to bottom. An annular sealing piece is arranged in each annular groove; the annular sealing piece comprises an open piston ring and a spring energy storage ring, a spring ring mounting groove is formed in the inner ring face of the open piston ring, the outer ring face of the spring energy storage ring is connected with the open piston ring through the spring ring mounting groove, the inner ring face of the spring energy storage ring abuts against the annular groove, and the spring energy storage ring is used for providing radial tensioning force which is uniform in the circumferential direction for the open piston ring; the open ends of the adjacent open piston rings in the annular groove are staggered, the outer ring diameter of each open piston ring is larger than the outer circle diameter of the piston body, the service life of the piston can be effectively prolonged, and good sealing performance of the piston is guaranteed.

Description

Technical Field

[0001] This utility model relates to a piston dynamic sealing structure, specifically a compensated dynamic sealing piston structure. Background Technology

[0002] In cryogenic environments such as LNG and liquid nitrogen, the dimensions of the piston and cylinder within the structure are greatly affected by temperature, and the gap between them changes with temperature. To ensure the service life and sealing performance of the piston, it is necessary to design elastic components on the piston seals for sealing compensation, in order to reduce the problem of increased gap caused by thermal expansion and contraction and wear, which leads to a decrease in sealing performance.

[0003] Because piston sealing design is difficult in low-temperature and high-pressure environments, the current technical approach is to arrange multiple seals in series on the piston, gradually reducing the pressure of the medium from the high-pressure side to the low-pressure side, in order to achieve the required sealing effect.

[0004] When multiple seals are arranged in series, they are subjected to high-pressure liquid pressure. Typically, the seals near the high-pressure side experience the greatest stress and friction, making them prone to wear and failure. Conversely, the seals near the low-pressure side experience less stress and wear. This results in varying wear and service life for seals at different locations on the piston. When the first seal near the high-pressure side fails, the stress on other seals increases, leading to accelerated wear. Uneven tension of the piston seals further deteriorates the sealing performance, severely impacting the service life and sealing performance of the entire piston dynamic seal structure. Therefore, it is essential to find a sealing structure that can provide elastic compensation and ensure uniform tension of the piston seals. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of inconsistent lifespan of seals at different positions in existing piston dynamic sealing structures, poor sealing performance, and uneven tension of piston seals, and to propose a compensating dynamic sealing piston structure.

[0006] To achieve the above objectives, the technical solution proposed by this utility model is as follows:

[0007] A compensated dynamic sealing piston structure includes a piston body, on which multiple annular grooves are evenly formed from top to bottom on the outer circumference of the piston body. The special feature is that an annular seal is provided in each of the annular grooves.

[0008] The annular seal includes an open piston ring and a spring accumulator ring. The two open ends of the open piston ring overlap. A spring ring mounting groove is provided on the inner ring surface of the open piston ring. The outer ring surface of the spring accumulator ring is connected to the open piston ring through the spring ring mounting groove. Its inner ring surface abuts against the bottom of the corresponding annular groove. The spring accumulator ring is used to provide a uniform radial tension force to the open piston ring.

[0009] The open ends of the open piston rings in adjacent annular grooves are staggered, and the outer ring diameter of the open piston ring is larger than the outer circle diameter of the piston body.

[0010] Furthermore, a support ring is provided on the top of the piston body.

[0011] The outer circumference of the support ring is uniformly provided with multiple grooves that pass through its upper and lower ends, which are used to throttle and reduce pressure on the piston body.

[0012] Furthermore, the stiffness of the spring energy storage coils within each of the aforementioned annular grooves is different.

[0013] Furthermore, the spring wire diameter, total number of spring coils, and spring diameter of each of the annular grooves are different, so as to make the radial tension force of the open piston ring in each of the annular grooves different.

[0014] Furthermore, the width of the open piston rings within each of the annular grooves is different.

[0015] Furthermore, both the open piston ring and the support ring are made of non-metallic wear-resistant materials;

[0016] The spring energy storage coil is made of a low-temperature resistant metal material.

[0017] Furthermore, both the open piston ring and the support ring are made of ultra-high molecular weight polyethylene.

[0018] Furthermore, the spring energy storage coil is made of 316 stainless steel.

[0019] Furthermore, the open ends of the open piston rings in adjacent annular grooves are offset by 180° from each other.

[0020] Furthermore, five annular grooves are evenly distributed from top to bottom on the outer circumference of the piston body.

[0021] The beneficial effects of this utility model are:

[0022] (1) The structure of the compensated dynamic sealing piston of this utility model is simple and easy to install. By adjusting the radial tension of the open piston ring through the spring energy storage ring, the clamping force between the piston body and the external mounting cylinder and the compensation amount between the open piston ring and the external mounting cylinder can be adjusted. This can not only effectively ensure the sealing performance of the piston, but also make the service life of the open piston ring at different positions on the piston body more consistent, which greatly improves the overall service life and sealing performance of the piston.

[0023] (2) This utility model uses a spring energy storage ring as an elastic adjustment component. Its elastic deformation is large and the compensation is large, which can ensure that the open piston ring is subjected to uniform radial tension force, ensure that the open piston ring does not deform, effectively reduce the risk of sealing leakage, and improve the overall sealing performance of the piston.

[0024] (3) By changing the stiffness of the spring energy storage ring in each annular groove, this utility model can change the clamping force and deformation of the open piston ring at different positions, which can effectively ensure that the life of the open piston ring at different positions tends to be consistent. For wear caused by different friction forces at different positions on the piston, targeted sealing adjustments can be made to effectively ensure the overall sealing performance of the piston and improve the overall service life of the piston. Furthermore, by increasing or decreasing the number of open piston rings and changing the stiffness of the spring energy storage ring, the sealing design of the piston can be adapted to different medium pressure environments, which effectively improves the applicability of the piston and makes it highly practical.

[0025] (4) By setting the outer ring diameter of the open piston ring to be larger than the outer diameter of the piston body, this utility model can effectively ensure the sealing of the inner wall of the cylinder body installed on the outside of the piston body.

[0026] (5) This utility model forms a labyrinth seal by staggering the opening ends of adjacent open piston rings in the annular groove on the outside of the piston body, which increases the leakage path, effectively reduces the leakage amount, and improves the overall sealing performance and sealing reliability of the piston structure.

[0027] The open ends of adjacent open piston rings are offset by 180° to each other, which further extends the leakage path and greatly improves the sealing performance of the piston body.

[0028] (6) By uniformly opening multiple grooves on the outer ring surface of the support ring, this utility model can ensure that the external medium flows through the grooves, thus ensuring that the open piston ring and piston body are subjected to uniform force, forming a throttling and pressure-reducing effect on the piston body, avoiding eccentric wear, greatly improving the overall strength and stability of the piston structure, and providing better support performance. Attached Figure Description

[0029] Figure 1This is a schematic diagram of an embodiment of a compensating dynamic seal piston structure according to the present invention;

[0030] Figure 2 This is a cross-sectional view of the piston body in an embodiment of the present utility model;

[0031] Figure 3 This is a schematic diagram of the structure of the annular seal in an embodiment of this utility model;

[0032] Figure 4 This is a schematic diagram of the support ring structure in an embodiment of the present invention;

[0033] Figure label:

[0034] 1-Open piston ring, 2-Spring accumulator ring, 3-Support ring, 4-Piston body, 5-Annular seal. Detailed Implementation

[0035] like Figure 1 and Figure 2 As shown, a compensated dynamic seal piston structure includes a piston body 4, with a support ring 3 on the top of the piston body 4 for uprighting and supporting the piston body 4, as shown. Figure 4 As shown, the outer ring surface of the support ring 3 is evenly provided with multiple grooves penetrating its upper and lower ends; the outer circumference of the piston body 4 is evenly provided with multiple annular grooves from top to bottom, and each annular groove is provided with an annular seal 5; as shown Figure 3 As shown, the annular seal 5 includes an open piston ring 1 and a spring accumulator ring 2. The two open ends of the open piston ring 1 overlap, and the open ends of adjacent open piston rings 1 in the annular groove are staggered. In this embodiment, the open ends of adjacent open piston rings 1 are staggered by 180°, which can effectively extend the leakage path and improve the sealing performance of the piston structure. A spring ring mounting groove is provided on the inner ring surface of the open piston ring 1. The outer ring surface of the spring accumulator ring 2 is connected to the open piston ring 1 through the spring ring mounting groove, and its inner ring surface abuts against the annular groove. The spring accumulator ring 2 is used to provide a uniform radial tension force to the open piston ring 1. The outer ring diameter of the open piston ring 1 is larger than the outer diameter of the piston body 4, which can make the piston body 4 fit tightly against the inner wall of the external mounting cylinder to form a seal.

[0036] In this embodiment, the open piston ring 1 and the support ring 3 are both non-metallic wear-resistant materials, both of which are ultra-high molecular weight polyethylene, and the spring energy storage ring 2 is a low-temperature resistant metal material, which is made of 316 stainless steel.

[0037] In this embodiment, the spring energy storage ring 2 is used as an elastic element, which can make the radial force on the circumference of the open piston ring 1 uniform, making it easier for the open piston ring 1 to maintain a circular shape, reducing the risk of leakage and improving the sealing performance. Furthermore, by changing the stiffness of the spring energy storage ring 2 in each annular groove, the clamping force and deformation of the open piston ring 1 can be changed. Spring energy storage rings 2 with different stiffnesses are installed on the open piston ring 1 at different positions, thereby adjusting the clamping force between the open piston ring 1 and the inner wall of the external mounting cylinder and the compensation amount of the open piston ring 1. Under the condition of ensuring sealing, the life of the open piston ring 1 in each annular groove tends to be consistent, thereby improving the overall service life of the piston body 4.

[0038] Meanwhile, for wear caused by different frictional forces at different locations on the piston, the radial tension of the open piston ring 1 can be changed by altering the width of the annular groove or the width of the open piston ring 1 at different locations. Since the radial tension of the open piston ring 1 varies at different locations, the sealing effect of the open piston ring 1 at different locations on the outer circumference of the piston body 4 varies. By obtaining the pressure drop pattern after sealing through the open piston ring 1 in each annular groove through experiments or simulations, the radial tension of the open piston ring 1 at different locations can be adjusted accordingly to make the pressure drop pattern smoother and the force on the open piston ring 1 at each location more consistent. This makes the service life of each open piston ring 1 more consistent, improves the overall service life of the piston, and ensures the sealing performance of the piston.

Claims

1. A compensating dynamic seal piston structure, comprising a piston body (4), a plurality of annular grooves are uniformly opened on the outer side circumference of the piston body (4) from top to bottom, characterized in that: An annular seal (5) is arranged in each of the annular grooves; The annular seal (5) comprises an open piston ring (1) and a spring energy storage ring (2), two open end portions of the open piston ring (1) are overlapped, a spring ring mounting groove is formed on an inner ring surface of the open piston ring (1), an outer ring surface of the spring energy storage ring (2) is connected with the open piston ring (1) through the spring ring mounting groove, and an inner ring surface of the spring energy storage ring (2) abuts against a bottom of the corresponding annular groove, and the spring energy storage ring (2) is used for providing a circumferentially uniform radial tension force to the open piston ring (1); Open end portions of the open piston rings (1) in adjacent annular grooves are arranged in a staggered manner, and an outer ring diameter of the open piston ring (1) is greater than an outer circle diameter of the piston body (4).

2. The compensation type dynamic sealing piston structure according to claim 1, characterized in that: A support ring (3) is arranged on a top portion of the piston body (4); A plurality of grooves penetrating through upper and lower end portions of the support ring (3) are uniformly arranged on an outer circumference of the support ring (3), and are used for forming throttling pressure reduction to the piston body (4).

3. The compensation type dynamic sealing piston structure according to claim 2, characterized in that: The spring energy storage rings (2) in each of the annular grooves are different in rigidity.

4. The compensation type dynamic sealing piston structure according to claim 3, characterized in that: The spring energy storage rings (2) in each of the annular grooves are different in spring wire diameter, total spring number and spring diameter, and are used for making the radial tension forces of the open piston rings (1) in each of the annular grooves different.

5. The compensation type dynamic sealing piston structure according to claim 2, characterized in that: The open piston rings (1) in each of the annular grooves are different in width.

6. A compensating dynamic seal piston structure according to claim 4 or 5, characterized in that: The open piston ring (1) and the support ring (3) are both non-metal wear-resistant materials; The spring energy storage ring (2) is a low-temperature resistant metal material.

7. The compensating dynamic seal piston structure of claim 6, wherein: The open piston ring (1) and the support ring (3) are both ultra-high molecular weight polyethylene.

8. The compensating dynamic seal piston structure of claim 7, wherein: The spring energy storage ring (2) is 316 stainless steel material.

9. The compensating dynamic seal piston structure of claim 8, wherein: The open end portions of the open piston rings (1) in adjacent annular grooves are staggered by 180°.

10. The compensating dynamic seal piston structure of claim 9, wherein: Five annular grooves are uniformly formed on an outer circumference of the piston body (4) from top to bottom.

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