Spring-polytetrafluoro-kerf combination resealable structure

Abstract

A spring-polytetrafluoroethylene-knife edge combined type repeatable sealing structure relates to a sealing assembly, and aims to solve the problems of poor temperature resistance and non-reusability of the existing sealing assembly.The sealing assembly comprises a sealing lip, a spring, a gland and a knife edge sealing assembly, a furnace cover is installed at a furnace opening of a furnace body, the sealing lip is arranged at the inner side of the furnace cover between the furnace cover and the furnace opening, the spring is installed in the sealing lip, the outer ring of the sealing lip is provided with an annular pressing edge, the annular pressing edge is fixedly connected with the furnace cover through the gland, and the knife edge sealing assembly is connected with the furnace cover and located at the inner ring of the sealing lip.The sealing assembly overcomes the defects of rubber material temperature resistance and metal knife edge use frequency, and has good redundancy backup safety and reliability.The application belongs to the technical field of sealing.

Description

Technical Field

[0001] This invention relates to a sealing assembly, specifically to a spring-PTFE-knife edge combination reusable sealing structure, and belongs to the field of sealing technology. Background Technology

[0002] Sealing technology for stellar regolith samples from extraterrestrial object sample return missions has always been a topic of great interest to researchers, as the quality of the seal directly affects the accuracy and reliability of ground-based data analysis. Currently, the sealing solutions used in sample return missions mainly include rubber ring seals, metal blade seals, and redundant combinations of both, each demonstrating good sealing performance under its respective operating environment.

[0003] The sealing component proposed in this invention is designed for in-situ extraction and analysis missions. Unlike sampling and return missions, the orbital soil samples do not need to be brought back to Earth; extraction and analysis can be performed directly in orbit. Orbital soil volatiles require temperatures as high as 900°C to be fully extracted, and the long lifespan of in-situ extraction and analysis missions necessitates that the seal possess high-temperature resistance and reusability. Rubber seals have poor temperature resistance and produce volatile gases at high temperatures, while metal blades require high force loads and are only for single use. Currently, there is a lack of a sealing component with good temperature adaptability, stable performance, and good reusability. Summary of the Invention

[0004] To address the problems of poor temperature resistance and non-reusability of existing sealing components, this invention proposes a spring-PTFE-knife edge combination reusable seal with better temperature adaptability, stable performance, and good reusability.

[0005] The technical solution adopted by the present invention to solve the above problems is as follows: The present invention includes a sealing lip, a spring, a pressure cap, and a knife-edge sealing assembly. The furnace cover is installed at the furnace opening of the furnace body. The sealing lip is located on the inner side of the furnace cover between the furnace cover and the furnace opening. The spring is installed inside the sealing lip. The outer ring of the sealing lip is provided with an annular pressure edge. The annular pressure edge is fixedly connected to the furnace cover through the pressure cap. The knife-edge sealing assembly is connected to the furnace cover and located at the inner ring of the sealing lip.

[0006] Furthermore, the sealing lip is made of polytetrafluoroethylene.

[0007] Furthermore, the spring is an O-type coil spring, and the spring is made of nickel-based high-temperature resistant material.

[0008] Furthermore, the knife-edge sealing assembly includes a soft metal ring, a dust-removing film, and a knife edge. The knife edge is located inside the sealing lip, with its lower end connected to the inner side of the furnace cover. The upper end of the knife edge is embedded in the soft metal ring, which is embedded in the furnace body. The dust-removing film is located between the upper end face of the knife edge and the lower end face of the soft metal ring.

[0009] Furthermore, the cutting edge is made of titanium alloy.

[0010] Furthermore, the soft metal ring is made of oxygen-free copper.

[0011] Furthermore, the dust-wiping film is an expanded polytetrafluoroethylene film.

[0012] Furthermore, an annular groove is provided on each of the upper and lower end faces of the sealing lip.

[0013] The beneficial effects of this invention are: 1. The sealing component of the present invention overcomes the temperature resistance defects of rubber materials and the limited number of uses of metal blades, and has good redundancy backup safety and reliability.

[0014] 2. The spring-PTFE seal that plays the main sealing role in this invention relies on the elastic-plastic matching between the built-in spring and PTFE. The spring undergoes elastic deformation under a predetermined load, which compensates for the creep defect of PTFE itself.

[0015] 3. The sealing material of this invention has good environmental adaptability, and the built-in O-ring spring can overcome the slight eccentricity of the mating surface, resulting in good stress conditions for the sealing element and good reusability. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the overall structure of the present invention; Figure 2 This is a cross-sectional view of the spring-PTFE sealing assembly of the present invention; Figure 3 This is a cross-sectional view of another form of the spring-PTFE sealing assembly of the present invention.

[0017] 1-Sealing lip; 1-1-Annular pressing edge; 2-Spring; 3-Soft metal ring; 4-Dust wiping film; 5-Knife edge; 6-Furnace body; 7-Pressure cover; 8-Furnace cover. Detailed Implementation

[0018] Specific implementation method one: Combining Figures 1 to 3 This embodiment describes a spring-PTFE-knife-edge combined reusable sealing structure, which includes a sealing lip 1, a spring 2, a pressure cap 7, and a knife-edge sealing assembly. The furnace cover 8 is installed at the furnace opening of the furnace body 6. The sealing lip 1 is located on the inner side of the furnace cover 8 between the furnace cover 8 and the furnace opening. The spring 2 is installed inside the sealing lip 1. The outer ring of the sealing lip 1 is provided with an annular pressure edge 1-1, which is fixedly connected to the furnace cover 8 through the pressure cap 7. The knife-edge sealing assembly is connected to the furnace cover 8 and is located at the inner ring of the sealing lip 1.

[0019] The internal spring 2 and the sealing lip 1 are assembled with a slight interference fit to ensure that the contact surface is subjected to uniform force during operation.

[0020] To restrict the movement of the seal, it is pressed tightly by the pressure cap 7 and fixed to the furnace cover 8 with screws, ensuring a compact and reliable overall structure. When the soil sample enters the heating furnace, the furnace body 6 is fixed, and the furnace cover 8, along with the sealing lip 1, moves towards the furnace body 6 under the action of the force-applying mechanism. The sealing lip deforms under pressure, filling the microscopic unevenness of the furnace body contact surface to establish initial sealing conditions. Under actual working conditions, the spring and sealing lip withstand the positive pressure generated by the heating volatiles inside the furnace, while the outside of the furnace is an ultra-high vacuum environment. With the seal opening facing inward, it can achieve a good self-sealing effect under the pressure difference between the inside and outside.

[0021] Specific Implementation Method Two: Combining Figures 1 to 3 In this embodiment, the sealing lip 1 is made of polytetrafluoroethylene (PTFE). The material used for the sealing lip 1 is PTFE, which has good temperature adaptability and stable performance.

[0022] The other components and connections are the same as in Specific Implementation Method 1.

[0023] Specific implementation method three: Combining Figures 1 to 3 In this embodiment, spring 2 is an O-type coil spring made of nickel-based high-temperature resistant material. The built-in O-type coil spring is made of nickel-based high-temperature resistant material, such as Inconel 600.

[0024] The other components are connected in the same way as in specific implementation method one or two.

[0025] Specific implementation method four: Combination Figure 1 This embodiment describes a knife-edge sealing assembly comprising a soft metal ring 3, a dust-removing film 4, and a knife edge 5. The knife edge 5 is located inside the sealing lip 1, with its lower end connected to the inner side of the furnace cover 8 and its upper end connected to the soft metal ring 3. The soft metal ring 3 is embedded in the furnace body 6, and the dust-removing film 4 is located between the upper end face of the knife edge 5 and the lower end face of the soft metal ring 3.

[0026] The knife-edge sealing assembly serves as a redundancy backup. Considering that any seal has a service life, and that the sealing lip of PTFE material will undergo irreversible creep under long-term mechanical and temperature conditions, the knife-edge sealing assembly plays an important role in maintaining a stable sealing effect after the spring-PTFE lip seal has been used several times and the sealing effect has decreased. Activating the knife-edge sealing assembly as a redundancy backup ensures the established good sealing effect.

[0027] Other components and connections are the same as in specific implementation methods one, two or three.

[0028] Specific Implementation Method Five: Combining Figure 1 This embodiment describes a cutting edge 5 made of titanium alloy. Other components and connections are the same as in specific embodiments one, two, three, or four.

[0029] Specific Implementation Method Six: Combination Figure 1 In this embodiment, the dust-wiping film 4 is an expanded polytetrafluoroethylene (ePTFE) film. The bottom of the soft metal ring 3 is covered with an ePTFE film. The density and flexibility of the film allow the blade to easily penetrate and wipe away traces of dust from its surface, thus ensuring a sealing effect.

[0030] Other components and connections are the same as in specific implementation methods one, two, three, four, or five.

[0031] Specific implementation method seven: Combining Figure 1 In this embodiment, the dust-wiping film 4 is an expanded polytetrafluoroethylene (ePTFE) film. The bottom of the soft metal ring 3 is covered with an ePTFE film. The density and flexibility of the film allow the blade to easily penetrate and wipe away traces of dust from its surface, thus ensuring a sealing effect.

[0032] Other components and connections are the same as in specific implementation methods one, two, three, four, five, or six.

[0033] Specific implementation method eight: Combination Figure 3 In this embodiment, the sealing lip 1 has an annular groove on each of its upper and lower end faces. With an annular groove on each of the upper and lower end faces of the sealing lip, and the sealing lip itself tilted at a slight angle, when an equal amount of dust falls onto the end face, some of it will fall into the dust-collecting groove. This dust does not participate in establishing a sealing contact condition; it only serves to contain any dust that may appear on the end face, ensuring a good sealing effect.

[0034] Other components and connections are the same as in specific implementation methods one, two, three, four, five, six, or seven.

[0035] Working principle: The regolith sample is fed into the heating furnace from the furnace opening. The upper furnace body remains stationary, while the force-applying mechanism slowly moves the furnace cover 8 along the furnace body. The sealing lip 1 contacts the furnace body 6 and undergoes elastoplastic deformation to fill the microscopic unevenness of the furnace body. The internal spring undergoes elastic deformation, providing spring reaction force to the contact surface, thereby increasing the predetermined sealing force and improving the sealing effect. The sealing force remains constant thereafter, establishing the initial sealing conditions. The regolith sample is heated in the heating furnace, producing volatiles. A certain pressure is generated in the sealed space inside the furnace, while the outside is a vacuum environment. This positive pressure environment promotes a tighter fit between the contact surfaces of the sealing lip 1, which is beneficial to the sealing to some extent. After a single regolith sample analysis, the sample is discarded through a sample disposal mechanism to prepare for the next analysis. The sealing lip and its internal spring, forming a seal, undergo the same steps described above. With increased use of the sealing lip and spring assembly, the surface of the seal will wear and undergo slight plastic deformation, leading to a decrease or even failure of the sealing effect. Due to the cumulative plastic deformation of the sealing lip 1, the knife-edge sealing assembly will establish sealing conditions. The blade embeds itself into the soft metal under the action of sealing force, causing it to undergo plastic deformation, thereby obstructing the leakage channel of volatiles and forming a sealing condition.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art should consult a professional before making any decisions. Without departing from the scope of the technical solution of this invention, when some modifications or alterations are made to the above-disclosed technical content to form equivalent embodiments, any simple modifications, equivalent substitutions and improvements made to the above embodiments within the spirit and principles of this invention, based on the technical essence of this invention, and without departing from the scope of the technical solution of this invention, shall still fall within the protection scope of this invention.

Claims

1. A spring-PTFE-knife edge combined reusable sealing structure, characterized in that: The spring-PTFE-knife-edge combined reusable sealing structure includes a sealing lip (1), a spring (2), a pressure cap (7), and a knife-edge sealing assembly. The furnace cover (8) is installed at the furnace opening of the furnace body (6). The sealing lip (1) is located on the inner side of the furnace cover (8) between the furnace cover (8) and the furnace opening. The spring (2) is installed inside the sealing lip (1). The outer ring of the sealing lip (1) is provided with an annular pressure edge (1-1). The annular pressure edge (1-1) is fixedly connected to the furnace cover (8) through the pressure cap (7). The knife-edge sealing assembly is connected to the furnace cover (8) and located at the inner ring of the sealing lip (1). The knife-edge sealing assembly plays a redundant backup role. Due to the cumulative effect of plastic deformation of the sealing lip (1), the knife-edge sealing assembly will establish sealing conditions. The sealing lip (1) has an annular groove on each of its upper and lower end faces; the sealing lip is tilted at a slight angle, and the annular grooves help to contain the dust that appears on the end face; the sealing lip (1) is made of polytetrafluoroethylene; the spring (2) is an O-type coiled spring, and the spring (2) is made of nickel-based high-temperature resistant material. The spring (2) and the sealing lip (1) are fitted together by an interference fit; Under pressure, the sealing lip (1) produces elastic deformation on the sealing contact surface, thereby establishing initial sealing conditions by filling the microscopic unevenness of the contact surface of the furnace body (6); the sealing lip (1) opens inward, and under the action of the internal and external pressure difference, it can play a self-sealing role. The spring (2) inside the sealing lip (1) undergoes elastic deformation under a given load, thus providing elastic support. The blade sealing assembly includes a soft metal ring (3), a dust-removing film (4), and a blade (5). The blade (5) is located inside the sealing lip (1). The lower end of the blade (5) is connected to the inner side of the furnace cover (8). The upper end of the blade (5) is embedded in the soft metal ring (3). The soft metal ring (3) is embedded in the furnace body (6). The dust-removing film (4) is located between the upper end face of the blade (5) and the lower end face of the soft metal ring (3). The blade (5) is made of titanium alloy. The soft metal ring (3) is made of oxygen-free copper material; The dust-wiping film (4) is an expanded polytetrafluoroethylene film. The material density and flexibility of the dust-wiping film (4) allow the blade (5) to penetrate and wipe the stardust on its surface.

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