Vacuum isolation valve external operation lead structure and thermostat

Abstract

This invention belongs to the technical field of high vacuum technology and core components of large scientific devices, and discloses an external operation lead-out structure for a vacuum isolation valve and a thermostat. The lead-out structure includes a rotating operating component, a vacuum sealing assembly, and a universal transmission mechanism. The first end of the rotating operating component is located outside the vacuum chamber of the thermostat, and the second end is located inside the vacuum chamber. The vacuum sealing assembly is sleeved on the rotating operating component and sealed to one end of the vacuum neck tube of the vacuum chamber. One end of the universal transmission mechanism is connected to the second end of the rotating operating component, and the other end is connected to the operating shaft of the vacuum isolation valve located inside the vacuum chamber. This lead-out structure can realize the opening and closing operation of the internal valve without damaging the ultra-high vacuum of the thermostat jacket, greatly improving the ease of operation, maintenance efficiency, and long-term operational reliability of large scientific devices such as superconducting accelerators.

Description

Technical Field

[0001] This invention relates to the fields of low-temperature superconductivity engineering, high vacuum technology and core components of large scientific facilities, and particularly to an external operation lead-out structure and thermostat for a vacuum isolation valve. Background Technology

[0002] With the development of modern physics, materials science, and aerospace technology, large scientific facilities such as heavy-ion accelerators, tokamak fusion devices, synchrotron radiation sources, and quantum computing test platforms are increasingly becoming the forefront of scientific research and industry. The core components of these devices typically operate in extremely low temperatures and ultra-high vacuum environments to eliminate interference from molecular thermal motion and gas molecule scattering, ensuring particle beam quality, plasma confinement performance, or qubit coherence time. In these devices, the cryostat is a key device for achieving and maintaining the extremely low temperature environment. Internally, it typically contains a cold mass string consisting of a superconducting cavity, superconducting magnet, coupler, tuner, etc. This cold mass string is housed within a vacuum chamber, which, together with external components such as cold shields and helium tanks, forms a complex multi-layered structure. To isolate different vacuum sections during assembly, maintenance, and operation, and to achieve rapid isolation in emergencies, manual ultra-high vacuum gate valves are usually installed at critical locations at both ends of the cold mass string. Once installed, these valves need to remain absolutely reliable throughout the entire commissioning, operation, and long-term service life of the cryostat.

[0003] The main problems and shortcomings of existing technologies: Extreme inconvenience in operation and maintenance: In traditional designs, these manual valves are installed directly inside the vacuum jacket of the thermostat. When valve operation is required, such as leak testing of the isolation system after initial installation or maintenance after a running cycle, the thermostat jacket must first be devastated—restored from an ultra-high vacuum state to atmospheric pressure. Subsequently, a significant amount of manpower and time is needed to disassemble the massive upper vacuum chamber or other related components before operators can access and manually operate the valves. This process not only takes days or even weeks but also requires the use of large lifting equipment, posing extremely high operational risks and personnel safety hazards.

[0004] A serious threat to system integrity and reliability: Each cycle of vacuum breaking and re-vacuuming is a severe test of the overall vacuum integrity of the thermostat. Atmospheric contaminants such as water vapor, dust, and grease can enter the originally clean ultra-high vacuum environment and adhere to the surfaces of critical components such as the cold mass string and radiation screen. During re-vacuuming, these contaminants are slowly released, severely deteriorating the vacuum level, prolonging evacuation time, and potentially causing high-voltage discharge, increased heat load, and other problems, directly affecting the performance of the superconducting cavity and the overall efficiency of the accelerator. Frequent disassembly and assembly can also lead to mechanical damage such as damage to flange sealing surfaces and stripped bolt threads, introducing potential irreversible leak points.

[0005] Unable to achieve remote and rapid response: During equipment operation, if an emergency shutdown of a valve section is required due to certain operating conditions, the traditional structure is completely incapable of achieving this. The process of breaking the vacuum and disassembling is extremely slow, failing to meet the requirements for rapid response. While electric or pneumatic valves could be considered, the reliability, magnetic compatibility, and additional heat load and vacuum leakage risks associated with electric actuators in complex environments such as extremely low temperatures, ultra-high vacuum, and strong magnetic fields present insurmountable technical obstacles, and are also extremely costly.

[0006] Therefore, there is an urgent need in this field for an innovative and highly reliable dedicated structure that can safely, conveniently, and reliably operate the internal valves from the outside without damaging the ultra-high vacuum of the thermostat jacket, thereby solving the aforementioned technical bottlenecks. Summary of the Invention

[0007] The purpose of this invention is to provide an external operation lead-out structure for a vacuum isolation valve. This lead-out structure enables the manual opening and closing of the internal valve from the outside at any time throughout the entire lifespan of the thermostat, which maintains the ultra-high vacuum in the jacket and the extremely low internal temperature, without any vacuum breaking or disassembly operations. This extends the thermostat's trouble-free operating time, reduces downtime, lowers maintenance difficulty, and prolongs the thermostat's lifespan.

[0008] The second objective of this invention is to provide a thermostat that, throughout its entire lifespan while maintaining the ultra-high vacuum and extremely low internal temperature of the jacket, allows for the opening and closing of the internal manual valves from the outside without any vacuum breaking or disassembly. This extends the thermostat's trouble-free operating time, reduces downtime, lowers maintenance difficulty, and extends the thermostat's lifespan.

[0009] To achieve this objective, the present invention adopts the following technical solution: This invention discloses an external operation lead-out structure for a vacuum isolation valve, comprising: a rotary operating member, the first end of which is located outside the vacuum chamber of a thermostat, and the second end of which is located inside the vacuum chamber; a vacuum sealing assembly, which is sleeved on the rotary operating member and sealed to one end of the vacuum neck tube of the vacuum chamber, the vacuum sealing assembly being used to ensure the vacuum seal of the vacuum chamber when the rotary operating member rotates; and a universal drive mechanism, one end of which is connected to the second end of the rotary operating member, and the other end of which is connected to the operating shaft of the vacuum isolation valve located inside the vacuum chamber; wherein, rotating the first end of the rotary operating member, the universal drive mechanism can drive the operating shaft to adjust the working state of the vacuum isolation valve.

[0010] In some embodiments, the rotating operating member includes a first shaft segment, a second shaft segment, and a third shaft segment connected in sequence. The first shaft segment has a mating hole for mating with a wrench or handwheel. The second shaft segment supports the vacuum sealing assembly and is sealed to the vacuum sealing assembly. The third shaft segment is mated with the universal joint mechanism.

[0011] In some specific embodiments, the second shaft segment is provided with a retaining ring groove, and a limiting retaining ring is provided in the retaining ring groove. The limiting retaining ring abuts against the vacuum sealing assembly and is used to prevent the rotating operating component from axially displacing into the vacuum chamber under the action of pressure difference.

[0012] In some embodiments, the vacuum sealing assembly includes: a connecting flange connected to the vacuum neck tube; an angle sealing flange, one side of which abuts against the connecting flange and is connected to the connecting flange and / or the outer wall of the vacuum chamber; and at least two vacuum dynamic seals, the at least two of which are axially spaced along the rotating operating member and located between the peripheral wall of the inner hole of the connecting flange and the outer wall of the rotating operating member.

[0013] In some specific embodiments, at least two first receiving grooves are provided on the peripheral wall of the inner hole of the connecting flange, and the at least two first receiving grooves are spaced apart along the axial direction of the connecting flange, and each first receiving groove is provided with a vacuum dynamic seal.

[0014] In some specific embodiments, the connecting flange is provided with a plurality of first fixing holes, the vacuum neck tube is connected to a neck tube flange, and the neck tube flange is provided with a plurality of second fixing holes. The plurality of first fixing holes and the plurality of second fixing holes are arranged in a one-to-one correspondence. A first fixing member passes through the first fixing holes and the second fixing holes to connect the connecting flange to the neck tube flange. Wherein, at least one of the connecting flange and the neck tube flange is provided with a second receiving groove, and a vacuum static seal is provided in the second receiving groove.

[0015] In some embodiments, the universal joint mechanism includes at least two universal joints, with two adjacent universal joints connected by an adjusting block. The adjusting block is detachably connected to the universal joint and is used to adjust the axial angle and spacing between two adjacent universal joints.

[0016] In some specific embodiments, each of the universal joints has a sleeve portion at both ends, and the sleeve portion has a third fixing hole. The adjusting block includes an integrally formed stop portion and two insertion portions. The two insertion portions are respectively connected to the two ends of the stop portion. The two ends of the insertion portions abut against the sleeve portions of two adjacent universal joints. The insertion portion has a fourth fixing hole. The insertion portion is inserted into the sleeve portion, and a second fixing member passes through the third fixing hole and the fourth fixing hole to lock the insertion portion and the sleeve portion. And / or, the second end of the rotating operating member is inserted into one of the sleeve portions and locked by the third fixing member inserted into the third fixing hole. And / or, the operating shaft on the vacuum isolation valve is inserted into the other sleeve portion and locked by the fourth fixing member inserted into the third fixing hole.

[0017] In some specific embodiments, the included angle between the axes of two adjacent universal joints is less than 30°.

[0018] The present invention also discloses a thermostat, including a vacuum chamber and the aforementioned external operation lead-out structure for a vacuum isolation valve. A vacuum isolation valve is provided in the vacuum chamber, and the external operation lead-out structure for the vacuum isolation valve cooperates with the vacuum isolation valve to adjust the vacuum isolation valve outside the vacuum chamber.

[0019] The beneficial effects of the aforementioned technology are as follows: Because the lead-out structure includes a rotary operating component, a vacuum sealing assembly, and a universal joint mechanism, with the first end of the rotary operating component located outside the vacuum chamber of the thermostat and the second end located inside the vacuum chamber and connected to the operating shaft of the vacuum isolation valve via the universal joint mechanism, operators can directly operate the vacuum isolation valve from outside the vacuum chamber using the rotary operating component during actual operation. This completely eliminates the traditional cumbersome process of breaking the vacuum, disassembling, operating, and restoring. Operators only need to rotate the rotary operating component from outside the thermostat using a handwheel or wrench to open or close the vacuum isolation valve within minutes, achieving non-invasive operation and significantly improving maintenance efficiency. Simultaneously, because the operation of the lead-out structure completely avoids the vacuum-breaking cycle, the clean ultra-high vacuum environment inside the thermostat's vacuum chamber is maintained consistently. This eliminates the risk of introducing contaminants, stabilizes the vacuum level, reduces the operating load of the vacuum pump unit, extends the system's trouble-free operating time, reduces downtime, lowers maintenance difficulty, and extends system lifespan.

[0020] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] Figure 1 This is a partial structural schematic diagram of the thermostat according to an embodiment of the present invention; Figure 2 yes Figure 1 A magnified diagram showing point A (circled). Figure 3 This is a partial cross-sectional view of the thermostat according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the cooperation structure between the external operation lead-out structure of the vacuum isolation valve and the vacuum isolation valve according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the external operation lead-out structure of the vacuum isolation valve according to an embodiment of the present invention; Figure 6 This is an exploded structural diagram of the external operation lead-out structure of the vacuum isolation valve according to an embodiment of the present invention.

[0022] Figure label: 100. Lead-out structure; 110. Rotary operating component; 111. First shaft section; 112. Second shaft section; 113. Third shaft section; 1121. Snap ring groove; 120. Vacuum sealing assembly; 121. Connecting flange; 1211. First receiving groove; 1212. Second receiving groove; 122. Angle sealing flange; 123. Vacuum dynamic seal; 124. Vacuum static seal; 130. Universal joint mechanism; 131. Universal cross joint; 1311. Sleeve section; 132. Adjusting block; 1321. Stop section; 1322. Insertion section; 140. Limit snap ring; 200. Thermostat; 210. Vacuum chamber; 220. Vacuum neck tube; 230. Neck tube flange; 300. Vacuum isolation valve. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0024] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] In the description of this embodiment, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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 the present invention. Furthermore, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0026] This invention discloses an external operation lead-out structure 100 for a vacuum isolation valve (hereinafter referred to as lead-out structure 100 for ease of description), see reference. Figures 1-6As shown, the lead-out structure 100 includes a rotary operating member 110, a vacuum sealing assembly 120, and a universal transmission mechanism 130. The first end of the rotary operating member 110 is located outside the vacuum chamber 210 of the thermostat 200, and the second end of the rotary operating member 110 is located inside the vacuum chamber 210. The vacuum sealing assembly 120 is sleeved on the rotary operating member 110 and is sealed to one end of the vacuum neck tube 220 of the vacuum chamber 210. The vacuum sealing assembly 120 is used to ensure the vacuum seal of the vacuum chamber 210 when the rotary operating member 110 rotates. One end of the universal transmission mechanism 130 is connected to the second end of the rotary operating member 110, and the other end is connected to the operating shaft of the vacuum isolation valve 300 located inside the vacuum chamber 210. By rotating the first end of the rotary operating member 110, the universal transmission mechanism 130 can drive the operating shaft to adjust the working state of the vacuum isolation valve 300. Understandably, since the lead-out structure 100 includes a rotary operating component 110, a vacuum sealing assembly 120, and a universal transmission mechanism 130, the first end of the rotary operating component 110 is located outside the vacuum chamber 210 of the thermostat 200, and the second end is located inside the vacuum chamber 210 and connected to the operating shaft of the vacuum isolation valve 300 through the universal transmission mechanism 130. In actual operation, the operator can directly operate the vacuum isolation valve 300 outside the vacuum chamber 210 by rotating the rotary operating component 110, completely eliminating the traditional cumbersome process of breaking the vacuum, disassembling, operating, and restoring. The operator only needs to rotate the rotary operating component 110 outside the thermostat 200 using a handwheel or wrench to complete the opening and closing of the vacuum isolation valve 300 within a few minutes, realizing non-invasive operation and significantly improving maintenance efficiency. At the same time, since the operation of the lead-out structure 100 completely avoids the vacuum breaking cycle, the clean ultra-high vacuum environment inside the vacuum chamber 210 of the thermostat 200 can be maintained from beginning to end. This eliminates the risk of introducing contaminants, stabilizes the vacuum level, reduces the operating load of the vacuum pump group, extends the system's trouble-free operation time, reduces downtime, lowers maintenance difficulty, and extends the system's lifespan.

[0027] Optionally, the rotary operating component 110 is made of 316 stainless steel, with a diameter of 20mm, and its surface is passivated to reduce the outgassing rate. The first end of the rotary operating component 110 is machined with a hexagonal head conforming to the standard wrench size, and a threaded hole is provided for mounting a handwheel. The handwheel is made of aluminum alloy and has an anti-slip texture. This allows for easy rotation of the rotary operating component 110 via the rotating handwheel, which in turn drives the operating shaft to rotate and adjust the working state of the vacuum isolation valve 300.

[0028] Optionally, the rotating operating component 110 includes a first shaft segment 111, a second shaft segment 112, and a third shaft segment 113 connected in sequence. The first shaft segment 111 has a mating hole for engaging with a wrench or handwheel. The second shaft segment 112 supports the vacuum sealing assembly 120 and is sealed to it. The third shaft segment 113 engages with the universal joint mechanism 130. It is understood that the rotating operating component 110, through the engagement of the first shaft segment 111 with a wrench or handwheel, facilitates operation by the operator using the handwheel or wrench. The second shaft segment 112 supports the vacuum sealing assembly 120, ensuring its stability and thus ensuring the sealing of the connection between the lead-out structure 100 and the vacuum chamber 210. The third shaft segment 113, engaging with the universal joint mechanism 130, ensures that the rotating operating component 110 can stably adjust the working state of the vacuum isolation valve 300 via the universal joint mechanism 130.

[0029] Optionally, the vacuum sealing assembly 120 includes a connecting flange 121, an angle sealing flange 122, and at least two vacuum dynamic seals 123. The connecting flange 121 is connected to the vacuum neck 220. One side of the angle sealing flange 122 abuts against the connecting flange 121 and is connected to the outer wall of the connecting flange 121 and / or the outer wall of the vacuum chamber 210. The at least two vacuum dynamic seals 123 are axially spaced along the rotating operating member 110 and located between the peripheral wall of the inner bore of the connecting flange 121 and the outer wall of the rotating operating member 110. It is understood that the connecting flange 121 is used to securely and sealingly mount the entire lead-out structure 100 to the vacuum neck 220 of the vacuum chamber 210, and the at least two vacuum dynamic seals 123 are designed to form a redundant sealing system. Even if one of the vacuum dynamic seals 123 experiences a minor leak after long-term use, the second vacuum dynamic seal 123 can still ensure the overall vacuum seal. At the same time, the gap between the two vacuum dynamic seals 123 can be connected to a leak detection port to achieve online status monitoring.

[0030] Optionally, the connecting flange 121 and the angle sealing flange 122 are connected by multiple connecting bolts. This simplifies the connection operation of the connecting flange 121 and the angle sealing flange 122, making assembly easier for the user, and also improves the connection stability and sealing performance of the connecting flange 121 and the angle sealing flange 122. In this embodiment, eight connecting bolts are used, and they are M85 bolts. Of course, in other embodiments of the present invention, adjustments can be made according to actual needs.

[0031] Optionally, the inner wall of the connecting flange 121 is provided with at least two first receiving grooves 1211, which are spaced apart along the axial direction of the connecting flange 121. Each first receiving groove 1211 contains a vacuum dynamic seal 123. It is understood that installing the two vacuum dynamic seals 123 respectively in the first receiving grooves 1211 of the connecting flange 121 ensures the connection stability of the vacuum dynamic seals 123, thereby ensuring the connection stability between the connecting flange 121 and the rotating operating member 110.

[0032] Alternatively, the material of the vacuum dynamic seal 123 can be a special material such as perfluoroether rubber or polyimide, which has high vacuum, low outgassing, and wear resistance.

[0033] Alternatively, the diameter of the vacuum dynamic seal 123 is 3 mm.

[0034] Alternatively, the angle sealing flange 122 can be made of 304 stainless steel forging with an inner bore accuracy of H6 and a surface finish of Ra<0.4μm.

[0035] Optionally, the connecting flange 121 is provided with multiple first fixing holes, and the vacuum neck flange 230 is connected to the vacuum neck flange 220. The neck flange 230 is provided with multiple second fixing holes, and the multiple first fixing holes and multiple second fixing holes are arranged one-to-one. A first fixing member passes through the first fixing holes and the second fixing holes to connect the connecting flange 121 to the neck flange 230. It can be understood that by using the first fixing member to connect the connecting flange 121 to the neck flange 230 through the first fixing holes and the second fixing holes, the connection operation of the connecting flange 121 and the neck flange 230 is simplified, making it convenient for users to assemble. On the other hand, the connection stability and sealing performance of the connecting flange 121 and the neck flange 230 are improved. In this embodiment, there are eight first fixing members, and they are M85 bolts. Of course, in other embodiments of the present invention, adjustments can be made according to actual needs.

[0036] Optionally, the connecting flange 121 is provided with a second receiving groove 1212, and a vacuum static seal 124 is provided in the second receiving groove 1212. It is understood that the vacuum static seal 124 between the connecting flange 121 and the neck flange 230 can ensure the sealing of the connection between the two and prevent the vacuum chamber 210 from leaking.

[0037] Alternatively, the vacuum static seal 124 can be a metal gasket (such as an oxygen-free copper gasket) or an elastomer (such as a fluororubber O-ring). Of course, in other embodiments of the invention, the second receiving groove 1212 can also be provided in the neck flange 230.

[0038] Optionally, the second shaft segment 112 is provided with a retaining ring groove 1121, and a limiting retaining ring 140 is provided in the retaining ring groove 1121. The limiting retaining ring 140 abuts against the vacuum sealing assembly 120 and is used to prevent the rotating operating member 110 from axially displacing into the vacuum chamber 210 under the action of pressure difference. It can be understood that the core function of the limiting retaining ring 140 is to resist the pressure difference caused by external atmospheric pressure (approximately 10). 5 The axial force generated by the huge pressure difference between the vacuum chamber 210 and the ultra-high vacuum inside the vacuum chamber 210 on the end face of the rotating operating component 110 is mitigated by the retaining ring 140, which engages with the retaining ring groove 1121 of the rotating operating component 110 and forms a mechanical limit with the end face of the angle sealing flange 122. This effectively prevents the rotating operating component 110 from being pushed into the vacuum chamber 210 under the pressure difference, thereby protecting the dynamic vacuum dynamic seal 123 from abnormal axial compression and wear, and ensuring the stability of the transmission position. Optionally, the retaining ring 140 is a standard bore elastic retaining ring; of course, other retaining ring structures can be selected according to actual needs.

[0039] Optionally, the universal joint mechanism 130 includes at least two universal joints 131. Two adjacent universal joints 131 are connected by an adjusting block 132, which is detachably connected to the universal joints 131. The adjusting block 132 is used to adjust the axial angle and spacing between the two adjacent universal joints 131. It is understood that the universal joints 131 can transmit torque within a certain angle and compensate for radial and angular deviations between the connecting shafts. The two adjacent universal joints 131 are connected by the adjusting block 132. In actual operation, by fine-tuning the connection positions at both ends of the adjusting block 132, the working angle between the two universal joints 131 can be changed, and the length of the entire universal joint mechanism 130 can also be fine-tuned to compensate for accumulated machining and installation errors, ensuring that the connection with the operating shaft is free from stress interference and excessive clearance.

[0040] Alternatively, the universal joint 131 may employ a high-precision, low-backlash universal joint with self-lubricating materials or solid lubricants at its joints to adapt to a vacuum environment.

[0041] Optionally, each universal joint 131 has a sleeve portion 1311 at both ends. The sleeve portion 1311 has a third fixing hole. The adjusting block 132 includes an integrally formed stop portion 1321 and two insertion portions 1322. The two insertion portions 1322 are respectively connected to the two ends of the stop portion 1321. The two ends of the insertion portions 1322 abut against the sleeve portions 1311 of the two adjacent universal joints 131. The insertion portions 1322 have a fourth fixing hole. The insertion portions 1322 are inserted into the sleeve portions 1311, and the second fixing member passes through the third fixing hole and the fourth fixing hole to lock the insertion portions 1322 and the sleeve portions 1311. Understandably, during actual installation, it is only necessary to insert the two plug-in parts 1322 into the sleeve parts 1311 of the two universal joints 131, and then the second fixing member passes through the third and fourth fixing holes to lock the plug-in parts 1322 and the sleeve parts 1311. This connection method is convenient to operate and has high reliability. In this embodiment, the second fixing member is a pin, but other fixing members can be selected according to actual needs.

[0042] Optionally, the second end of the rotating operating member 110 is inserted into one of the sleeve portions 1311 and locked by a third fixing member inserted into the third fixing hole. It is understood that in actual installation, the second end of the rotating operating member 110 is inserted into one of the sleeve portions 1311, and then the third fixing member passes through the third fixing hole to lock the rotating operating member 110 and the sleeve portion 1311. This connection method is convenient to operate and has high reliability. In this embodiment, the third fixing member is a pin, but other fixing members can be selected according to actual needs.

[0043] Optionally, the operating shaft on the vacuum isolation valve 300 is inserted into another sleeve portion 1311 and locked by a fourth fixing member inserted into the third fixing hole. It is understood that in actual installation, the operating shaft is inserted into one of the sleeve portions 1311, and then the third fixing member passes through the third fixing hole to lock the operating shaft and the sleeve portion 1311. This connection method is convenient to operate and has high reliability. In this embodiment, the fourth fixing member is a pin, but other fixing members can be selected according to actual needs.

[0044] Optionally, the included angle between the axes of two adjacent universal joints 131 is less than 30°. It is understood that an excessively large included angle between the axes of two adjacent universal joints 131 can lead to a sharp decrease in transmission efficiency, a sharp increase in rotational torque, and even jamming. In this embodiment, an included angle between the axes of two adjacent universal joints 131 is less than 30° effectively avoids jamming. Preferably, the included angle between the axes of two adjacent universal joints 131 is less than 15°.

[0045] This invention also discloses a thermostat 200, including a vacuum chamber 210 and the aforementioned external operation lead-out structure 100 for a vacuum isolation valve. A vacuum isolation valve 300 is disposed within the vacuum chamber 210. The external operation lead-out structure 100 cooperates with the vacuum isolation valve 300 to adjust the vacuum isolation valve 300 from the outside of the vacuum chamber 210. Due to the aforementioned lead-out structure 100, the thermostat 200 can be manually operated from the outside at any time throughout its entire lifespan, maintaining the ultra-high vacuum of the jacket and the extremely low internal temperature, without requiring any vacuum breaking or disassembly. This extends the fault-free operating time of the thermostat 200, reduces downtime, lowers maintenance difficulty, and extends the lifespan of the thermostat 200.

[0046] Optionally, the thermostat 200 body is a large cylindrical vacuum container. A cold mass string runs through it. Two lead-out structures 100, as described above, are symmetrically mounted on the neck tubes on both sides of the vacuum chamber 210 of the thermostat 200, respectively aligned with the vacuum isolation valves 300 at both ends of the cold mass string. This bilateral symmetrical design ensures the modularity and consistency of the system.

[0047] The manufacturing, assembly, and commissioning process of the external operation lead-out structure 100 of this vacuum isolation valve is as follows: Component pretreatment: After machining, all components undergo thorough ultrasonic cleaning, deionized water rinsing and dust-free drying, followed by vacuum baking to degas and ensure an ultra-low outgassing rate.

[0048] Module pre-assembly: In a cleanroom environment, first assemble the rotary operating component 110, limit snap ring 140, angle sealing flange 122, connecting flange 121, and two vacuum dynamic seals 123 into a dynamic sealing sub-module. Then connect the two universal joints 131 and the adjusting block 132 with pins to form a transmission chain sub-module.

[0049] On-site installation: a. During the assembly of thermostat 200, after the cold mass series is in place, first remove the original handles of the vacuum isolation valves 300 at both ends.

[0050] b. Fit the inner end of the pre-assembled transmission chain module onto the operating shaft of the vacuum isolation valve 300, and lock it to the operating shaft with a pin.

[0051] c. Connect the outer end of the entire transmission chain submodule to the dynamic sealing submodule, and then move the entire lead-out structure 100 into place so that the connecting flange 121 is aligned with the neck flange 230.

[0052] d. Place a new oxygen-free copper gasket between the flanges, and then tighten the bolts gradually in a diagonal sequence to the specified torque to install the lead-out structure 100 onto the neck flange 230.

[0053] e. At this time, the first end of the rotating operating element 110 should extend from the center of the connecting flange 121.

[0054] Centering and gap adjustment: a. Manually try rotating the rotating part 110. Initially, it may feel heavy or stuck.

[0055] b. By slightly loosening the connecting pin on the adjusting block 132, the position of the adjusting block 132 is finely adjusted, thereby changing the angle of the universal joint 131 and the length of the drive chain module.

[0056] c. Repeatedly fine-tune and test-rotate until the rotating operating part 110 feels smooth and fluid, without any jamming points throughout its entire stroke. Use an angle gauge to measure and ensure that the working angle between the two universal joints 131 is no greater than 15°.

[0057] d. Finally, hammer all the pins into place completely and install cotter pins or spring clips to prevent them from falling out.

[0058] Final acceptance: Install the handwheel onto the rotary operating component 110. Before evacuating the thermostat 200 and after the required vacuum level is achieved, perform multiple complete opening and closing tests of the vacuum isolation valve 300, record the operating torque, and ensure that the vacuum level in the vacuum chamber 210 does not deteriorate throughout the entire process.

[0059] Work process (usage method flow): Initial status confirmation: Thermostat 200 is in normal operating condition, and the vacuum level of vacuum chamber 210 is stable at 5.0 × 10⁻⁶. -6 Pa, with its internal cold mass series immersed in superfluid helium at 2K.

[0060] Operation command issued: Due to changes in the experimental plan or abnormal parameters detected in a certain area, it is necessary to close the vacuum isolation valve 300 on one side.

[0061] Performing external operation: The operator walks to one side of the thermostat 200 and grasps the handwheel. After confirming that everything is correct, smoothly rotate the handwheel according to the valve opening direction.

[0062] Torque transmission path: The rotation of the handwheel drives the rotating operating component 110 to rotate. The rotating operating component 110 rotates under the tight wrapping of two vacuum dynamic seals 123. The lip of the sealing ring forms an extremely thin lubricating and sealing film with the surface of the rotating operating component 110, maintaining a torque of 10 with minimal friction. -8 Pa·m 3With an extremely low leakage rate on the order of / s, the second end of the rotating operating element 110 drives the input torque of the first universal joint 131, which is transmitted to the adjusting block 132 through the first universal joint 131, and then drives the input end of the second universal joint 131. The output end of the second universal joint 131 transmits the rotational motion directly to the operating shaft of the vacuum isolation valve 300 through the pin. The operating shaft drives the internal valve plate or valve stem to overcome the pre-tight sealing force and achieve precise displacement from fully open to fully closed (or vice versa).

[0063] Status feedback and confirmation: The vacuum isolation valve 300 is usually equipped with a position indicator. The operator can confirm that the vacuum isolation valve 300 has reached the predetermined position by observing the indicator or by observing changes in system pressure.

[0064] Operation complete: Operation completed. Throughout the entire process, the vacuum gauge reading in vacuum chamber 210 remained stable, the system temperature was stable, and the ultra-high vacuum environment and extremely low temperature operation of thermostat 200 were unaffected.

[0065] The advantages of the external operation lead-out structure 100 for the vacuum isolation valve of the present invention are as follows: First, it achieves non-invasive operation, significantly improving maintenance efficiency: it completely eliminates the traditional cumbersome process of breaking the vacuum, disassembling, operating, and restoring. Operators only need to turn the rotating operating component 110 from outside the thermostat 200 using a handwheel or wrench to open or close the vacuum isolation valve 300 within minutes. This shortens the maintenance cycle from several days or even weeks to just a few minutes, greatly improving maintenance efficiency, saving valuable experimental time for large scientific facilities, and significantly reducing operating costs. Secondly, it maximizes the integrity and long-term reliability of the system's vacuum: By completely avoiding vacuum breaking cycles, the clean ultra-high vacuum environment inside the vacuum chamber 210 of the thermostat 200 can be maintained consistently. This eliminates the risk of introducing contaminants, stabilizes the vacuum level, reduces the operating load of the vacuum pump group, extends the system's trouble-free operation time, reduces downtime, lowers maintenance difficulty, and extends the system's lifespan. It also improves the data quality and operational reliability of the entire scientific device while saving huge costs throughout the entire life cycle of the large scientific device. Third, it enhances operational safety and emergency response capabilities: operators no longer need to disassemble or assemble in confined spaces or using heavy equipment, significantly reducing personal safety risks. More importantly, during operation, if a minor leak or need for isolation is detected in a certain area, the corresponding valves can be immediately shut off from the outside, enabling rapid emergency response—a proactive safety function that traditional structures simply cannot achieve. Fourth, redundant sealing and limiting design: The combination of the dual vacuum dynamic seal 123 and the limiting snap ring 140 constitutes an extremely reliable dynamic sealing system, effectively coping with the challenges of long-term wear and huge pressure difference of the device. Fifth, the universal drive and adjustable design, the introduction of universal cross joint 131 and adjusting block 132, solve the unavoidable dimensional chain error and thermal deformation problems in large-scale projects, ensure smooth and efficient transmission, high torque transmission efficiency, and avoid local stress concentration and mechanism jamming. Sixth, modular design: the entire structure can be installed and maintained as a pre-installed module, which facilitates mass production and quick replacement, improves the engineering level of the entire thermostat 200 system, and the manufacturing cost is far lower than that of electric or pneumatic actuators specifically developed for ultra-low temperature and ultra-high vacuum environments.

[0066] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0067] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An external operation lead-out structure for a vacuum isolation valve, characterized in that, include: A rotating operating member (110) has a first end located outside the vacuum chamber (210) of the thermostat and a second end located inside the vacuum chamber (210). A vacuum sealing assembly (120) is sleeved on the rotating operating member (110) and sealed to one end of the vacuum neck tube (220) of the vacuum chamber (210). The vacuum sealing assembly (120) is used to ensure the vacuum seal of the vacuum chamber (210) when the rotating operating member (110) rotates. A universal drive mechanism (130) is provided, one end of which is connected to the second end of the rotary operating member (110), and the other end is connected to the operating shaft of the vacuum isolation valve (300) located in the vacuum chamber (210). By rotating the first end of the rotary operating member (110), the universal drive mechanism (130) can drive the operating shaft to adjust the working state of the vacuum isolation valve (300).

2. The external operation lead-out structure of the vacuum isolation valve according to claim 1, characterized in that, The rotating operating component (110) includes a first shaft segment (111), a second shaft segment (112), and a third shaft segment (113) connected in sequence. The first shaft segment (111) has a mating hole for mating with a wrench or handwheel. The second shaft segment (112) is used to support the vacuum sealing assembly (120) and is sealed to the vacuum sealing assembly (120). The third shaft segment (113) is mated with the universal transmission mechanism (130).

3. The external operation lead-out structure of the vacuum isolation valve according to claim 2, characterized in that, The second shaft segment (112) is provided with a snap ring groove (1121), and a limiting snap ring (140) is provided in the snap ring groove (1121). The limiting snap ring (140) abuts against the vacuum sealing assembly (120) and is used to prevent the rotating operating member (110) from axially displacing into the vacuum chamber (210) under the action of pressure difference.

4. The external operation lead-out structure of the vacuum isolation valve according to any one of claims 1-3, characterized in that, The vacuum sealing assembly (120) includes: A connecting flange (121) is connected to the vacuum neck tube (220); An angle sealing flange (122) abuts against the connecting flange (121) on one side and is connected to the outer wall of the connecting flange (121) and / or the vacuum chamber (210). At least two vacuum dynamic seals (123) are provided at an axial distance from the rotary operating member (110) and are located between the peripheral wall of the inner hole of the connecting flange (121) and the outer wall of the rotary operating member (110).

5. The external operation lead-out structure of the vacuum isolation valve according to claim 4, characterized in that, At least two first receiving grooves (1211) are provided on the peripheral wall of the inner hole of the connecting flange (121). The at least two first receiving grooves (1211) are spaced apart along the axial direction of the connecting flange (121), and each first receiving groove (1211) is provided with a vacuum dynamic seal (123).

6. The external operation lead-out structure of the vacuum isolation valve according to claim 4, characterized in that, The connecting flange (121) is provided with a plurality of first fixing holes, and a neck flange (230) is connected to the vacuum neck (220). The neck flange (230) is provided with a plurality of second fixing holes, and the plurality of first fixing holes and the plurality of second fixing holes are arranged in a one-to-one correspondence. A first fixing member passes through the first fixing holes and the second fixing holes to connect the connecting flange (121) to the neck flange (230); wherein: At least one of the connecting flange (121) and the neck flange (230) is provided with a second receiving groove (1212), and a vacuum static seal (124) is provided in the second receiving groove (1212).

7. The external operation lead-out structure for the vacuum isolation valve according to any one of claims 1-3, characterized in that, The universal drive mechanism (130) includes at least two universal joints (131). Two adjacent universal joints (131) are connected by an adjusting block (132). The adjusting block (132) is detachably connected to the universal joints (131). The adjusting block (132) is used to adjust the axial angle and spacing between two adjacent universal joints (131).

8. The external operation lead-out structure of the vacuum isolation valve according to claim 7, characterized in that, Each of the universal joints (131) has a sleeve portion (1311) at both ends. The sleeve portion (1311) has a third fixing hole. The adjusting block (132) includes an integrally formed stop portion (1321) and two insertion portions (1322). The two insertion portions (1322) are respectively connected to the two ends of the stop portion (1321). The two ends of the insertion portion (1322) abut against the sleeve portions (1311) of the two adjacent universal joints (131). The insertion portion (1322) has a fourth fixing hole. The insertion portion (1322) is inserted into the sleeve portion (1311), and the second fixing member passes through the third fixing hole and the fourth fixing hole to lock the insertion portion (1322) and the sleeve portion (1311); and / or, The second end of the rotating operating member (110) is inserted into one of the sleeve portions (1311) and locked by a third fixing member inserted into the third fixing hole; and / or, The operating shaft on the vacuum isolation valve (300) is inserted into another sleeve (1311) and locked by a fourth fastener inserted into the third fixing hole.

9. The external operation lead-out structure of the vacuum isolation valve according to claim 7, characterized in that, The included angle between the axes of two adjacent universal joints (131) is less than 30°.

10. A thermostat, characterized in that, Includes a vacuum chamber (210) and an external operation lead-out structure for a vacuum isolation valve as described in any one of claims 1-9, wherein a vacuum isolation valve (300) is provided inside the vacuum chamber (210), and the external operation lead-out structure for the vacuum isolation valve cooperates with the vacuum isolation valve (300) to adjust the vacuum isolation valve (300) outside the vacuum chamber (210).

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