A seal assembly for a rotary moving push rod

Abstract

The application belongs to the technical field of optical fiber preparation, and specifically discloses a sealing assembly of a rotating and moving push rod, a cover plate of the sealing assembly is covered on an upper end opening of a muffle tube, and a first hole is arranged on the cover plate; a sealing structure main body comprises a sealing shell and a sealing ring, the sealing shell seals the first hole and forms an accommodating cavity in the interior, a push rod movably penetrates through the sealing shell, the sealing ring is arranged in the accommodating cavity and sleeved on the push rod, and an annular gap is formed between the sealing ring and the push rod; the annular gap is located between the outer side walls of the sealing ring and the push rod, a through hole in communication with the annular gap is formed on the sealing ring, a gas extraction channel in communication with the through hole is formed on the sealing shell, and a vacuum pump is connected with the gas extraction channel. By driving the sealing ring to deform, the push rod and the sealing shell are dynamically and closely fitted, and the path of axial leakage of harmful gas in the muffle tube along the push rod is effectively isolated. The sealing assembly is especially suitable for high-temperature and positive pressure working conditions in which the push rod simultaneously rotates and moves axially.

Description

Technical Field

[0001] This application belongs to the field of optical fiber fabrication technology, and more specifically, relates to a sealing assembly for a rotating movable push rod. Background Technology

[0002] In the optical fiber fabrication process, during the fabrication of the optical fiber preform, a muffle tube (a tubular core component in industrial heat treatment equipment used to contain samples and provide heating space) is placed in a furnace such as a resistance furnace, induction furnace, or silicon molybdenum rod sintering furnace and heated to above 1000°C. The powder rod is then pushed through a cover plate by a pusher and into the muffle tube. During production, the muffle tube, cover plate, pusher, etc., are all located in a sealed space with a certain positive pressure, which is isolated from the external space. Simultaneously, a mixture of gases, including but not limited to nitrogen, helium, sulfur dioxide, and hydrogen sulfide, may be introduced into the muffle tube. Some of these gases, such as sulfur dioxide and hydrogen sulfide, are harmful to human health.

[0003] During the production process, the push rod needs to rotate or move up and down relative to the cover plate. Therefore, it is necessary to ensure the sealing between the push rod and the sealing cover during rotation and movement under high temperature conditions to prevent the leakage of harmful gases. There are currently no relevant research results. Summary of the Invention

[0004] In response to the deficiencies or improvement needs of the prior art, this application provides a sealing assembly for a rotating push rod, which aims to solve the technical problem that poor sealing between the push rod and the cover plate during the optical fiber preform preparation process can lead to the leakage of harmful gases.

[0005] This application provides a sealing assembly for a rotary moving push rod, including a cover plate, a push rod, a sealing structure body, and a vacuum pump; The cover plate is installed over the upper opening of the muffle tube, and the cover plate is provided with a first hole; The sealing structure includes a sealing shell and a sealing ring. The sealing shell seals the first hole and has an internal cavity. The push rod moves through the sealing shell. The sealing ring is disposed in the cavity and fitted onto the push rod. An annular gap is formed between the sealing ring and the push rod. The annular gap is located between the outer walls of the sealing ring and the push rod. A through hole communicating with the annular gap is formed on the sealing ring. An air extraction channel communicating with the through hole is formed on the sealing shell. The vacuum pump is connected to the air extraction channel. The sealing ring is configured to deform under the action of upper and / or lower air pressure so that the inner wall of the sealing ring fits against the push rod and the outer wall fits against the inner wall of the cavity.

[0006] The main body of the sealing structure also includes at least one annular seal, which is fitted onto the outside of the push rod and is located at the upper and / or lower end of the sealing ring.

[0007] As a further preferred embodiment, the sealing ring includes a ring body, the upper end and the lower end of the ring body extending radially inward to form an annular upper sealing section and a lower sealing section, respectively, and the annular gap is defined by the lower end wall of the upper sealing section, the inner side wall of the ring body, the upper end wall of the lower sealing section and the outer side wall of the push rod.

[0008] As a further preferred embodiment, the sealing housing includes a base and a pressure cap; the base is disposed in the first hole and forms a second hole communicating with the first hole, the upper end of the base forms a first groove, the pressure cap is mounted on the base and forms a third hole communicating with the second hole; the lower end of the pressure cap forms a second groove, and the first groove and the second groove define the receiving cavity.

[0009] As a further preferred embodiment, the lower end of the base protrudes downward to form a tenon, which is inserted into the first hole.

[0010] As a further preferred embodiment, the air extraction channel is formed on the side of the base or the cover.

[0011] As a further preferred embodiment, the bottom of the first groove and / or the second groove is formed with an annular groove for placing the annular seal.

[0012] As a further preferred embodiment, the sealing assembly further includes an exhaust protective cover, which is sealed and installed on the upper end of the pressure cover, and a protective cavity is formed between the exhaust protective cover and the pressure cover. An exhaust port for connecting to a vacuum pump is formed on the exhaust protective cover.

[0013] As a further preferred embodiment, the lower end of the exhaust protective cover has an installation port, and the upper end of the pressure cover protrudes upward to form a boss, which is fitted into the installation port.

[0014] As a further preferred embodiment, the annular seal is any one of an O-ring, a Glyd ring, or a composite seal.

[0015] In summary, compared with the prior art, the technical solutions conceived in this application have the following main technical advantages: 1. The sealing assembly provided in this application, through the design of a cover plate, push rod, sealing housing, sealing ring, and vacuum pump, achieves this by having the push rod move through the sealing housing and the sealing ring positioned within the receiving cavity and fitted onto the push rod, creating an annular gap between the sealing ring and the push rod. The vacuum pump actively draws air from this annular gap, establishing a stable pressure difference between the upper and lower ends of the sealing ring. This pressure difference drives the sealing ring to deform, causing it to dynamically and tightly conform to the push rod and sealing housing, effectively isolating the path of harmful gas leakage along the push rod axially within the muffle tube. This is particularly suitable for high-temperature, positive-pressure conditions where the push rod simultaneously rotates and moves axially, solving the technical problem of traditional static seals being unable to adapt to dynamic motion.

[0016] 2. The annular seal creates a multi-level sealing barrier. As an auxiliary or backup seal, the annular seal provides additional sealing protection even under extreme operating conditions when the sealing performance of the sealing ring temporarily fluctuates or maintenance is required. This significantly improves the reliability and safety of the entire sealing assembly and reduces the risk of gas leakage.

[0017] 3. By defining the annular gap through a specific structural design, the internal and external pressure difference generated by vacuum pumping can be applied precisely and effectively to the upper and lower sealing sections of the sealing ring. This optimizes the stress on the sealing ring and ensures that it can produce more controllable and uniform deformation under the pressure difference, thereby achieving a more stable and superior dynamic sealing contact.

[0018] 4. The split-type sealing housing design facilitates the installation, inspection, and replacement of internal components such as the sealing ring and annular seal, significantly improving maintenance convenience. Simultaneously, the sealing fit between the gland and the base enhances the overall sealing reliability of the structure.

[0019] 5. The design of the exhaust protective cover forms a second active protection barrier. Even if a small amount of gas escapes from the main body of the sealed structure under extreme conditions, it will be confined within the protective cavity and promptly removed by the vacuum pump to prevent it from spreading to the external operating environment. Attached Figure Description

[0020] Figure 1 This is a cross-sectional schematic diagram of the sealing assembly of a rotary push rod in use, provided in an embodiment of this application. Figure 2 This is a schematic diagram of the connection between the sealing structure body and the push rod in a rotary moving push rod according to an embodiment of this application; Figure 3 This is a schematic diagram of the connection between the sealing ring and the push rod in a rotating push rod according to an embodiment of this application.

[0021] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1. Cover plate; 1a. First hole; 2. Push rod; 3. Sealing structure main body; 31. Sealing shell; 31a. Receiving cavity; 31b. Air extraction channel; 311. Base; 311a. Second hole; 311b. First groove; 3111. Tenon; 312. Pressure cap; 312a. Third hole; 312b. Second groove; 3121. Boss; 32. Sealing ring; 32a. Annular gap; 32b. Through hole; 321. Ring body; 322. Upper sealing section; 323. Lower sealing section; 33. Annular seal; 4. Vacuum pump; 5. Exhaust fan protective cover; 5a. Protective cavity; 5b. Exhaust vent; 5c. Mounting port; 6. Muffle tube. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0023] like Figures 1 to 3 As shown, this application provides a sealing assembly for a rotating push rod, including a cover plate 1, a push rod 2, a sealing structure body 3, and a vacuum pump 4.

[0024] The cover plate 1 is installed on the upper opening of the muffle tube 6, and the cover plate 1 is provided with a first hole 1a.

[0025] The sealing structure body 3 includes a sealing shell 31 and a sealing ring 32. The sealing shell 31 seals the first hole 1a and has an internal accommodating cavity 31a. The push rod 2 moves through the sealing shell 31. The sealing ring 32 is disposed in the accommodating cavity 31a and is fitted onto the push rod 2. An annular gap 32a is formed between the sealing ring 32 and the push rod 2. The annular gap 32a is located between the outer walls of the sealing ring 32 and the push rod 2. A through hole 32b communicating with the annular gap 32a is formed on the sealing ring 32. An air extraction channel 31b communicating with the through hole 32b is formed on the sealing shell 31. The vacuum pump 4 is connected to the air extraction channel 31b. The sealing ring 32 is configured to deform under the action of air pressure at the upper end and / or the lower end, so that the inner wall of the sealing ring 32 fits against the push rod 2 and the outer wall fits against the inner wall of the accommodating cavity 31a.

[0026] The sealing assembly provided in this application, through the design of a cover plate 1, a push rod 2, a sealing housing 31, a sealing ring 32, and a vacuum pump 4, utilizes the push rod 2 to move through the sealing housing 31. The sealing ring 32 is located in the receiving cavity 31a and fitted onto the push rod 2, forming an annular gap 32a between the sealing ring 32 and the push rod 2. The vacuum pump 4 actively draws air from this annular gap 32a, establishing a stable pressure difference between the upper and lower ends of the sealing ring 32. This pressure difference drives the sealing ring 32 to deform, thereby dynamically and tightly fitting against the surface of the push rod 2, effectively isolating the path of harmful gas leakage along the axial direction of the push rod 2 within the muffle tube 6. This design is particularly suitable for high-temperature, positive-pressure conditions where the push rod 2 simultaneously rotates and moves axially, solving the technical problem of traditional static seals being unable to adapt to dynamic motion.

[0027] In practical use, both the sealing component and the muffle tube 6 are located in a slightly positive pressure environment. At the same time, the inside of the muffle tube 6 is also filled with a composite gas, so that the upper and lower ends of the annular gap 32a have a relatively high gas pressure. When the inside of the annular gap 32a is evacuated to form a negative pressure, a stable pressure difference can be generated inside and outside the annular gap 32a, thereby ensuring that the sealing ring 32 is always in a passive deformation state and ensuring sealing stability.

[0028] The sealing structure body 3 also includes at least one annular seal 33, which is fitted on the outside of the push rod 2 and located at the upper and / or lower end of the sealing ring 32.

[0029] The annular seal 33 forms a multi-level sealing barrier. As an auxiliary or backup seal, the annular seal 33 provides additional sealing protection even when the sealing performance of the sealing ring 32 temporarily fluctuates or requires maintenance under extreme operating conditions, significantly improving the reliability and safety of the entire sealing assembly and reducing the risk of gas leakage. In the embodiments of this application, there are two annular seals 33, located at the upper and lower ends of the sealing ring 32, respectively. In optional embodiments, provided the sealing barrier is maintained, the annular seal 33 may be provided only at the upper or lower end of the sealing ring 32; this will not be elaborated upon here.

[0030] As part of the structural design of the sealing ring 32 in this embodiment, the sealing ring 32 includes a ring body 321. The upper end and lower end of the ring body 321 extend radially inward to form an annular upper sealing section 322 and a lower sealing section 323, respectively. The annular gap 32a is defined by the lower end wall of the upper sealing section 322, the inner side wall of the ring body 321, the upper end wall of the lower sealing section 323, and the outer side wall of the push rod 2.

[0031] The specific structural design defines the annular gap 32a, allowing the internal and external pressure difference generated by vacuum pumping to act precisely and effectively on the upper sealing section 322 and the lower sealing section 323 of the sealing ring 32. This optimizes the stress on the sealing ring 32, ensuring that it can produce more controllable and uniform deformation under the pressure difference, thereby achieving a more stable and superior dynamic sealing contact.

[0032] In an embodiment of this application, the sealing housing 31 includes a base 311 and a pressure cap 312; the base 311 is disposed in the first hole 1a and has a second hole 311a communicating with the first hole 1a, the upper end of the base 311 has a first groove 311b, the pressure cap 312 is fitted onto the base 311 and has a third hole 312a communicating with the second hole 311a; the lower end of the pressure cap 312 has a second groove 312b, and the first groove 311b and the second groove 312b define the receiving cavity 31a.

[0033] The split-type sealing housing 31 design facilitates the installation, inspection, and replacement of internal parts such as the sealing ring 32 and the annular seal 33, greatly improving maintenance convenience.

[0034] The base 311 has a tenon 3111 protruding downwards at its lower end, which is inserted into the first hole 1a. The tenon 3111 structure achieves precise positioning and initial sealing between the base 311 and the cover plate 1, preventing gas leakage from the installation interface between the sealing housing 31 and the cover plate 1, while enhancing the mechanical stability and alignment of the component installation. Preferably, a sealing structure, not limited to a sealing ring, is also installed between the lower end face of the base 311 and the cover plate 1.

[0035] Correspondingly, based on the aforementioned split design, the evacuation channel 31b is formed on the side of the base 311 or the pressure cap 312. In this embodiment, for example, the evacuation channel 31b is formed on the side of the pressure cap 312. Placing the evacuation channel 31b on the side makes connecting the vacuum pipeline more convenient, avoids interference that might occur to the movement of the push rod 2 or other parts of the equipment if the pipeline runs from the top or bottom, and optimizes the equipment layout and space utilization.

[0036] To facilitate the installation of the annular component, the bottom of the first groove 311b and / or the second groove 312b is formed with an annular groove for placing the annular seal 33. The annular groove provides precise installation positioning and limiting space for the annular seal 33, preventing it from shifting or twisting under pressure or equipment vibration, and ensuring stable sealing performance.

[0037] Optionally, the annular seal 33 can be any one of an O-ring, a Glyd ring, or a composite seal.

[0038] To further improve the dynamic seal stability and prevent failure due to long-term use, the sealing assembly also includes an exhaust protection cover 5. The exhaust protection cover 5 is sealed and installed on the upper end of the cover 312. A protective cavity 5a is formed between the exhaust protection cover 5 and the cover 312. An exhaust port 5b for connecting to the vacuum pump 4 is formed on the exhaust protection cover 5.

[0039] The exhaust hood 5 and the exhaust port 5b form a second active protection barrier. Even in extreme situations or during long-term use, if a trace amount of gas escapes through the sealed structure 3 from the muffle tube 6, it will be confined within the protective cavity 5a and promptly removed by the vacuum pump 4, preventing it from spreading to the external operating environment and greatly improving personnel safety and environmental protection levels.

[0040] Similar to the design of the base 311 mentioned above, the exhaust protective cover 5 and the pressure cover 312 also adopt a mortise and tenon structure design. Specifically, the lower end of the exhaust protective cover 5 has an installation port 5c, and the upper end of the pressure cover 312 has an upward protrusion 3121. The protrusion 3121 is fitted into the installation port 5c. This centering and fitting structure achieves quick and accurate positioning and reliable sealing connection between the exhaust protective cover 5 and the pressure cover 312, ensuring the airtightness of the protective cavity 5a, while simplifying the installation and disassembly process. Overall, the embodiments of the present invention can effectively ensure the sealing and stability of the push rod 2 and the cover plate 1 during rotational movement under high temperature conditions, effectively preventing the leakage of toxic gases and preventing external gases from entering the muffle tube 6, improving the quality of optical fiber products, reducing water peak value, thereby ensuring the safety of operators, improving optical fiber strength, and reducing optical fiber attenuation.

[0041] It should be understood that expressions such as "comprising" and "may include" as used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "comprising" and / or "having" may be interpreted as indicating a specific characteristic, number, operation, constituent element, component, or combination thereof, but should not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0042] It should be understood that the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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 application.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0044] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0045] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A sealing assembly for a rotary movable push rod, characterized in that, Includes cover plate (1), push rod (2), sealing structure body (3) and vacuum pump (4); The cover plate (1) is installed over the upper opening of the muffle tube (6), and the cover plate (1) is provided with a first hole (1a). The sealing structure body (3) includes a sealing shell (31) and a sealing ring (32). The sealing shell (31) seals the first hole (1a) and has an internal accommodating cavity (31a). The push rod (2) moves through the sealing shell (31). The sealing ring (32) is disposed in the accommodating cavity (31a) and fitted onto the push rod (2). An annular gap (32a) is formed between the sealing ring (32) and the push rod (2). The annular gap (32a) is located at the sealing ring (32). Between the outer wall of the push rod (2), a through hole (32b) communicating with the annular gap (32a) is formed on the sealing ring (32), and an air extraction channel (31b) communicating with the through hole (32b) is formed on the sealing housing (31). The vacuum pump (4) is connected to the air extraction channel (31b). The sealing ring (32) is configured to deform under the action of the upper and / or lower air pressure so that the inner wall of the sealing ring (32) fits against the push rod (2) and the outer wall fits against the inner wall of the accommodating cavity (31a).

2. The sealing assembly of the rotary movable push rod according to claim 1, characterized in that, The sealing structure body (3) also includes at least one annular seal (33), which is fitted on the outside of the push rod (2) and located at the upper and / or lower end of the sealing ring (32).

3. The sealing assembly of the rotary moving push rod according to claim 1 or 2, characterized in that, The sealing ring (32) includes a ring body (321), the upper end and the lower end of the ring body (321) extend radially inward to form an annular upper sealing section (322) and a lower sealing section (323), respectively. The annular gap (32a) is defined by the lower end wall of the upper sealing section (322), the inner side wall of the ring body (321), the upper end wall of the lower sealing section (323) and the outer side wall of the push rod (2).

4. The sealing assembly of the rotary movable push rod according to claim 2, characterized in that, The sealing housing (31) includes a base (311) and a pressure cap (312); the base (311) is disposed in the first hole (1a) and forms a second hole (311a) communicating with the first hole (1a); a first groove (311b) is formed at the upper end of the base (311); the pressure cap (312) is sealed on the base (311) and forms a third hole (312a) communicating with the second hole (311a); a second groove (312b) is formed at the lower end of the pressure cap (312); the first groove (311b) and the second groove (312b) define the receiving cavity (31a).

5. The sealing assembly of the rotary movable push rod according to claim 4, characterized in that, The lower end of the base (311) protrudes downward to form a tenon (3111), which is inserted into the first hole (1a).

6. The sealing assembly of the rotary movable push rod according to claim 4, characterized in that, The air extraction channel (31b) is formed on the side of the base (311) or the cover (312).

7. The sealing assembly of the rotary movable push rod according to claim 4, characterized in that, The bottom of the first groove (311b) and / or the second groove (312b) is formed with an annular groove for placing the annular seal (33).

8. The sealing assembly of the rotary movable push rod according to claim 4, characterized in that, The sealing assembly also includes a ventilation protective cover (5), which is sealed and installed on the upper end of the cover (312). A protective cavity (5a) is formed between the ventilation protective cover (5) and the cover (312), and a ventilation port (5b) for connecting to the vacuum pump (4) is formed on the ventilation protective cover (5).

9. The sealing assembly of the rotary movable push rod according to claim 8, characterized in that, The lower end of the exhaust protective cover (5) is provided with an installation port (5c), and the upper end of the pressure cover (312) protrudes upward to form a boss (3121), which is fitted into the installation port (5c).

10. The sealing assembly of the rotary movable push rod according to claim 2, characterized in that, The annular seal (33) is any one of an O-ring, a Glyd ring, or a composite seal.

Images