Connection assembly for a refrigerator cold head and refrigerator

Abstract

The application provides a connecting assembly for a cold head of a refrigerator and the refrigerator. The connecting assembly comprises a cold lead structure and a pressing member. The cold lead structure comprises a first connecting member and a second connecting member connected in sequence along the length direction of the cold lead structure. The first connecting member is used for fixedly abutting with a cold lead surface of the cold head. The second connecting member is provided with a mounting hole for fixedly mounting a heat sink. The pressing member is sleeved on the outer peripheral side of the second connecting member. The pressing member is contracted along the radial direction of the pressing member and is pressed against the outer wall surface of the second connecting member as the temperature decreases. The inner wall surface of the second connecting member is pressed against the outer wall surface of the heat sink. The connecting assembly greatly simplifies the disassembly process of the refrigerator, avoids the sealing failure and component damage caused by repeated disassembly, and reduces the risk of failure of the superconducting magnet device.

Description

Technical Field

[0001] This invention relates to the field of refrigeration technology, and in particular to a connection assembly for a refrigeration machine cold head, and a refrigeration machine including such a connection assembly. Background Technology

[0002] In industrial production and scientific research, there is often a need to maintain specific spaces or equipment in a low-temperature environment. Therefore, refrigerators are widely used in industrial production and scientific research. Specifically, refrigerators can effectively reduce the temperature of target objects through specific refrigeration principles to meet the low-temperature requirements in different scenarios. For example, in the field of superconducting technology, the normal operation of superconducting magnets cannot be separated from the support of a low-temperature environment, and refrigerators are key equipment for providing a stable low-temperature environment for superconducting coils.

[0003] Currently, the cold head for cooling superconducting magnets in cryogenic refrigerators is mostly placed inside a vacuum chamber. These superconducting magnets typically employ a two-stage refrigerator. The secondary cooling surface of the cold head is threaded to the 4K end heat sink, and the primary cooling surface is similarly threaded to the 50K radiation screen end heat sink. While this connection method meets daily cooling needs, it presents significant drawbacks when repairing or replacing the cryogenic refrigerator cold head.

[0004] The specific maintenance process requires first shutting down the refrigeration unit and waiting for the cold source inside the cryogenic container to gradually return to room temperature (300K). Then, the vacuum environment of the cryogenic container is disrupted, followed by the sequential removal of the vacuum cylinder and the 50K radiation screen. Only then can the cold head be removed for repair or replacement. This process not only significantly increases the workload for staff and prolongs the maintenance cycle, but also, due to repeated disassembly and vacuum disruption, exacerbates the risk of seal failure and component damage in the superconducting magnet, impacting the stability and reliability of the superconducting magnet equipment. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problem that in the prior art, the cold head of the refrigeration unit and the heat sink of the refrigerated equipment are usually connected by bolts, which is troublesome to disassemble, greatly increases the workload of maintenance personnel, and prolongs the maintenance cycle. Especially in the field of superconducting magnets, this exacerbates the risk of failure such as sealing failure and component damage of superconducting magnets, and affects the stability and reliability of superconducting magnet equipment.

[0006] To address the aforementioned technical problems, embodiments of the present invention disclose a connecting assembly for a refrigeration unit cold head. This connecting assembly includes a cooling structure and a clamping member. The cooling structure includes a first connecting member and a second connecting member connected sequentially along its length. The end of the first connecting member away from the second connecting member is used to fit and fix with the cooling surface of the cold head. The second connecting member is provided with a mounting hole for fixing and installing a heat sink. The clamping member is sleeved on the outer periphery of the second connecting member. As the temperature decreases, the clamping member contracts radially inward and presses against the outer wall surface of the second connecting member, so that the inner wall surface of the second connecting member is pressed tightly against the outer wall surface of the heat sink.

[0007] Using the above technical solution, this connecting component connects the cold head and heat sink of the refrigerator through a cold-conducting structure, thereby realizing the transfer of cold energy. The first connecting member of the cold-conducting structure is fixedly attached to the guide surface of the cold head, while the second connecting member is connected to the heat sink through a mounting hole. Furthermore, a clamping member is sleeved on the outer periphery of the second connecting member. As the temperature decreases, the clamping member presses the second connecting member tightly, so that the inner wall surface of the second connecting member is pressed tightly against the outer wall surface of the heat sink, reducing heat loss during the cold conduction process and improving the efficiency of cold energy transfer. Especially in the field of superconducting technology, it provides a more stable low-temperature environment for maintaining the superconducting state of the superconducting coil.

[0008] Furthermore, compared to the existing technology that uses bolts to connect the cold head and heat sink, this connecting component reduces the tedious operation of bolt disassembly and assembly. When repairing or replacing the cold head of the refrigerator, the staff does not need to disassemble the internal components of the superconducting magnet equipment such as the vacuum cylinder and radiation screen. They only need to stop the refrigerator from working, and as the temperature rises, the clamping parts gradually loosen the second connecting parts, which allows the cooling structure to detach from the heat sink. This greatly reduces the workload, shortens the maintenance cycle, and also reduces the probability of sealing failure and component damage in the superconducting magnet, thus improving the stability and reliability of the superconducting magnet equipment.

[0009] In addition, the cooling structure of this connecting component can be assembled with most of the cold heads of the refrigeration unit, and has a wide range of applications.

[0010] The present invention discloses a connection assembly for a cold head of a refrigerator. The cooling structure further includes a flexible cooling element. In the length direction of the cooling structure, the flexible cooling element is located between the first connector and the second connector and connects the first connector and the second connector. The flexible cooling element can deform in a direction perpendicular to the length direction of the cooling structure.

[0011] As the temperature decreases, the clamping member contracts radially inward and presses against the outer wall of the second connector. The second connector contracts radially inward, so that the inner wall of the second connector is pressed tightly against the outer wall of the heat sink. The flexible cooling component bends inward from the end connected to the second connector in a direction perpendicular to the length of the cooling structure.

[0012] Using the above technical solution, the flexible cooling conductor located between the first connector and the second connector can bend and deform with the radial contraction of the second connector, avoiding the stress caused by the contraction of the second connector that could lead to the breakage of the cooling structure or loosening of the connection. At the same time, it always maintains a continuous cooling path between the first connector, the flexible cooling conductor, and the second connector, ensuring that the cold energy is stably transferred to the heat sink, and further optimizing the cooling effect.

[0013] Furthermore, compared to rigid connections, the deformation capability of flexible cooling components can buffer the rigid force exerted on the first connecting component (and the cooling head cooling surface) and the second connecting component (and the heat sink) when the second connecting component contracts, reducing the probability of mechanical damage such as cracks and wear caused by stress concentration in various components. Especially in the field of superconducting magnets, it can further ensure the reliability of superconducting magnet equipment.

[0014] In addition, the deformable nature of the flexible cooling component can tolerate a certain degree of assembly error (such as the coaxiality deviation between the first and second connectors), reducing assembly difficulty; during maintenance and disassembly, there is no need to strictly calibrate the position of each component, reducing secondary failures caused by insufficient assembly accuracy, further shortening the maintenance cycle and reducing the workload.

[0015] The present invention also discloses a connection assembly for a refrigeration unit cold head. The first connector includes a connection body and a connection flange. The connection body is configured as a columnar structure extending along the length direction of the cooling structure. The connection flange is connected to the end of the connection body away from the second connector and constitutes the end of the first connector away from the second connector.

[0016] The flexible cooling component includes multiple flexible cooling wires, one end of which is fixedly connected to the corresponding part of the first connector, and the other end is fixedly connected to the corresponding part of the second connector.

[0017] The second connector includes a plurality of fan-shaped connecting plates spaced apart circumferentially along the second connector. The plurality of fan-shaped connecting plates together define a mounting hole. The end of each fan-shaped connecting plate near the first connector is fixedly connected to a corresponding flexible cooling wire. Furthermore, a connecting hole is formed on the outer wall of each fan-shaped connecting plate. Fasteners are fixed in the corresponding connecting holes by passing through the side wall of the clamping member radially along the clamping member, so that the corresponding fan-shaped connecting plate is fixedly connected to the clamping member, and the clamping member presses against the outer wall of the fan-shaped connecting plate.

[0018] The first connector is designed as a columnar structure extending along the length of the cooling structure, providing basic support for the cooling path. The connecting flange is connected to the end of the connector away from the second connector and is used to fit and fix with the cooling surface of the cold head, improving the contact area and connection stability between the cooling structure and the cooling surface of the cold head. The flexible cooling component consists of multiple flexible cooling lines, taking into account both flexible deformation and cold energy conduction efficiency. The second connector includes multiple fan-shaped connecting plates spaced apart along its circumference. The multiple fan-shaped connecting plates together define the mounting holes for installing heat sinks. Each fan-shaped connecting plate is fixedly connected to the corresponding flexible cooling line at the end closest to the first connector. The clamping component is fixed to each fan-shaped connecting plate by fasteners, which can effectively limit the circumferential displacement of the fan-shaped connecting plates and prevent misalignment of the fan-shaped connecting plates during temperature changes.

[0019] When a single sector-shaped connecting plate or a single cooling wire in this type of cooling structure is damaged, the impact on the overall cooling path is relatively small. The remaining components can still ensure the basic conduction of cold energy and connection stability. Especially in the field of superconducting magnets, it can reduce the risk of superconducting magnets losing superheat due to connection component failure. During maintenance, only the damaged parts can be replaced, avoiding the failure of the entire connection component due to local failure, which greatly reduces maintenance costs and equipment downtime.

[0020] The present invention also discloses a connecting assembly for a refrigeration unit cold head, the connecting assembly further including a circumferential limiting assembly, and the clamping member being connected to the first connecting member through the circumferential limiting assembly.

[0021] The first connector also includes a limiting flange, which is connected to one end of the connecting body near the second connector. One end of the multiple flexible cooling wires is fixedly connected to the alignment part of the limiting flange. Furthermore, a circumferential limiting component is disposed on the outer periphery of the multiple flexible cooling wires. One end of the circumferential limiting component is connected to the alignment part of the limiting flange, and the other end is connected to the corresponding part of the clamping component.

[0022] Using the above technical solution, the circumferential limiting component surrounds the outer periphery of the flexible cooling line and is connected to the first connector through the limiting flange. This directly restricts the relative circumferential rotation between the clamping component and the first connector. At the same time, since the clamping component is fixed to multiple sector connecting plates by fasteners, the risk of circumferential displacement of multiple sector connecting plates is reduced, avoiding circumferential misalignment of components due to temperature changes or vibrations. This ensures that the mounting holes enclosed by the second connector are always precisely aligned with the heat sink, preventing damage caused by uneven stress on the heat sink.

[0023] In addition, the circumferential limiting component can prevent the flexible cooling wire from being stretched or squeezed due to misalignment by limiting the circumferential displacement of each component, ensuring that each flexible cooling wire maintains a relatively stable connection state and cooling path; at the same time, it avoids the gap between the inner wall of the second connector and the outer wall of the heat sink from increasing due to component misalignment, further reducing the loss of cold energy during the conduction process and ensuring the low-temperature stability required by the superconducting magnet.

[0024] The embodiments of the present invention also disclose a connecting assembly for a refrigeration unit cold head, wherein the clamping member is configured as a clamping sleeve, and the clamping sleeve is sleeved on the outer periphery of a plurality of sector-shaped connecting plates.

[0025] Furthermore, a plurality of limiting holes are provided at intervals along the circumference at one end of the compression sleeve near the first connecting member. The circumferential limiting assembly includes a plurality of limiting posts. The plurality of limiting posts are provided at intervals along the circumference of the flexible cooling component on the outer periphery of the flexible cooling component. The plurality of limiting posts correspond one-to-one with the plurality of limiting holes. One end of each limiting post is embedded in the corresponding limiting hole, and the other end is connected to the alignment part of the limiting flange.

[0026] Using the above technical solution, the clamping sleeve is fitted around the outer periphery of multiple sector-shaped connecting plates. Its annular structure can evenly transmit its radial contraction force to the outer wall surface of each sector-shaped connecting plate. At the same time, the cooperation between the limiting post and the limiting hole prevents the clamping sleeve from shifting circumferentially. On the one hand, it can accurately constrain the circumferential position of the sector-shaped connecting plates, avoiding circumferential shift of the sector-shaped connecting plates caused by temperature changes or equipment vibration, ensuring that the mounting hole enclosed by the second connector is always accurately aligned with the heat sink, and preventing damage to the heat sink due to force shift. On the other hand, it ensures that the pressure of the clamping sleeve on each sector-shaped connecting plate is consistent, causing all sector-shaped connecting plates to contract radially synchronously, so that the inner wall surface of the second connector and the outer wall surface of the heat sink are fully and tightly fitted, reducing local fitting gaps and further reducing cold loss.

[0027] An embodiment of the present invention also discloses a connecting assembly for a refrigeration unit cold head, wherein an elastic gasket is pressed between the outer wall surface of a plurality of fan-shaped connecting plates and the inner wall surface of a compression sleeve.

[0028] Indium sheets are installed between the inner wall of multiple fan-shaped connecting plates and the outer wall of the heat sink, and between the connecting flange and the cold-conducting surface of the cold head, and coated with low-temperature thermally conductive adhesive.

[0029] By adopting the above technical solution, elastic gaskets are set between the outer wall surface of multiple sector-shaped connecting plates and the inner wall surface of the clamping sleeve. The elastic gaskets can undergo elastic deformation with the radial contraction of the clamping sleeve. On the one hand, they can fill the processing errors or minor unevenness between the outer wall surface of the sector-shaped connecting plates and the inner wall surface of the clamping sleeve, ensuring uniform pressure transmission. On the other hand, when temperature changes cause slight fluctuations in the contraction of the clamping sleeve, the elastic gaskets can compensate for the pressure changes through their own deformation, avoiding excessive local pressure that could damage the components or insufficient pressure that could cause the clamping sleeve and heat sink assembly to loosen, thus always maintaining a stable clamping state of the sector-shaped connecting plates on the heat sink.

[0030] Furthermore, the indium sheet possesses excellent low-temperature ductility and thermal conductivity, allowing it to tightly fit into tiny gaps on the contact surface and eliminate air gaps (air has a low thermal conductivity and easily forms a bottleneck for heat conduction); combined with the high thermal conductivity of the low-temperature thermally conductive adhesive, it can further reduce the thermal resistance between the fan-shaped connecting plate and the heat sink, and between the connecting flange and the cold head's heat conduction surface, achieving efficient transfer of cold energy and reducing the loss of cold energy at the contact surface.

[0031] In addition, the low-temperature thermally conductive adhesive not only improves thermal conductivity but also has a certain sealing performance, which can prevent external impurities (such as dust and moisture) from entering the bonding gap between the fan-shaped connecting plate and the heat sink, and between the connecting flange and the cold head cooling surface. At the same time, the tight bonding of the indium sheet can also block the intrusion of impurities, avoiding contact surface corrosion and decreased thermal conductivity caused by impurity accumulation, or sealing failure and component damage caused by impurities entering the vacuum cavity of the superconducting magnet, further ensuring the stability of the superconducting magnet equipment.

[0032] The embodiments of the present invention also disclose a connecting assembly for a refrigeration unit cold head, wherein any one of the first connecting member, the second connecting member, and the flexible heat-conducting member is made of copper, oxygen-free copper, or silver, and the clamping member is made of polytetrafluoroethylene, perfluoroalkoxyalkane, or fluorinated ethylene propylene.

[0033] Using the above technical solution, copper, oxygen-free copper, and silver all have extremely high thermal conductivity. The first connector, the second connector, and the flexible heat-conducting component made of any of the above materials can quickly transfer the cold energy of the cold head, so that the loss of cold energy during the transfer process is minimal. For example, in superconducting magnet equipment, the heat sink temperature can be quickly reduced to the low temperature range required by the superconducting magnet, ensuring that the superconducting coil can stably maintain the superconducting state.

[0034] Polytetrafluoroethylene, perfluoroalkoxyalkanes, and fluorinated ethylene propylene have excellent low-temperature stability. Even at extremely low temperatures, they can maintain good elasticity and structural integrity and will not harden or crack due to temperature reduction. Clamping parts made of the above materials can stably achieve radial shrinkage and clamping function as the temperature decreases.

[0035] The present invention also discloses a refrigerator, which includes a refrigerator body, a first cold head, a second cold head, a first connecting assembly, and a second connecting assembly. One end of the first cold head is connected to the refrigerator body, and the other end is connected to the second cold head. The first cold head is connected to a first heat sink through the first connecting assembly, and the second cold head is connected to a second heat sink through the second connecting assembly. Both the first connecting assembly and the second connecting assembly adopt any of the above-mentioned connecting assemblies for refrigerator cold heads. The first connecting assembly has a first cooling structure and a first clamping member. The second connecting assembly has a second cooling structure and a second clamping member.

[0036] Furthermore, the refrigerator also includes a support cylinder, one end of which is fixed and sealed to the refrigerator body, and the other end is fixed and sealed to the outer wall of the vacuum chamber.

[0037] The first cold head extends into the support cylinder from one end of the support cylinder. The first cold head is provided with a first cold guiding surface. The first cold guiding surface is attached and fixed to the first connecting member of the first cold guiding structure. The first connecting member and the first heat sink of the first cold guiding structure are configured as hollow structures. The first cold head passes through the first cold guiding structure and is connected to the second cold head located in the first heat sink and extending from the other end of the support cylinder. The second cold head is provided with a second cold guiding surface. The second cold guiding surface is attached and fixed to the first connecting member of the second cold guiding structure.

[0038] Using the above technical solution, the first cold head of this refrigerator is connected to the first heat sink via a first connecting component, and the second cold head is connected to the second heat sink via a second connecting component, forming a two-stage refrigeration structure that can simultaneously provide stable low temperatures for heat sinks with different temperature requirements. Furthermore, both the first and second connecting components utilize a heat-conducting structure and clamping parts, eliminating the need for disassembling numerous components as with traditional bolted connections. During maintenance, there is no need to damage the vacuum chamber (the support cylinder is sealed to the vacuum chamber, maintaining its vacuum). Only after the cold head temperature rises again can the clamping parts be loosened radially, directly separating the cold head (the upper-connected heat-conducting structure) from the heat sink. This significantly reduces disassembly workload and shortens the maintenance cycle. Especially in superconducting magnet equipment, it avoids seal failure and component damage caused by repeated disassembly and reassembly, reducing the risk of equipment malfunction.

[0039] The present invention also discloses a refrigeration machine, wherein a connecting plate is provided between one end of the support cylinder and the refrigeration machine body, one side of the connecting plate along its thickness direction is fitted and fixedly connected to one end face of the support cylinder, and the other side is fitted and fixedly connected to the corresponding outer wall surface of the refrigeration machine body.

[0040] By adopting the above technical solution, one side of the connecting plate along its thickness direction is fitted and fixedly connected to one end face of the support cylinder, and the other side is fitted to the corresponding outer wall surface of the refrigeration unit body. This can evenly distribute the connection load between the support cylinder and the refrigeration unit body (such as the weight of the support cylinder and the vibration load during the operation of the cold head) to a larger contact area, avoiding deformation of the support cylinder port or damage to the outer wall surface of the refrigeration unit body caused by local stress concentration. Especially in low temperature environments, metal components (support cylinder, refrigeration unit body) are prone to stress due to thermal expansion and contraction. The buffering effect of the connecting plate can reduce the impact of stress on the sealing surface, prevent the sealing ring from being squeezed and damaged due to component deformation, and extend the service life of the sealing structure.

[0041] An embodiment of the present invention also discloses a refrigerator, wherein sealing rings are provided between one side of the connecting plate and one end face of the support cylinder, and between the other side of the connecting plate and the corresponding outer wall surface of the refrigerator body. Furthermore, vacuum silicone grease is applied to the outer surface of the sealing rings.

[0042] By adopting the above technical solution, the sealing performance between the connecting plate and the refrigerator body and support cylinder is improved by the sealing ring. Furthermore, the vacuum grease applied to the sealing ring has excellent wettability and fluidity, which can tightly fill the tiny pores between the sealing ring and the mating surface (such as microscopic unevenness left by component processing, and the tiny gaps formed after the sealing ring is compressed), preventing the vacuum degree of the vacuum chamber from decreasing and ensuring the stability of the high vacuum environment required by the superconducting magnet.

[0043] The beneficial effects of this invention are as follows:

[0044] This invention discloses a connection assembly for a cold head of a refrigerator. This assembly includes a cooling structure and a clamping member. A first connector of the cooling structure is fixedly fitted to the guide surface of the cold head, while a second connector connects to a heat sink through a mounting hole. The clamping member is sleeved on the outer periphery of the second connector. As the temperature decreases, the clamping member presses the second connector tightly, causing the inner wall of the second connector to adhere tightly to the outer wall of the heat sink. This reduces heat loss during cooling and improves the efficiency of cold energy transfer, especially in the field of superconducting technology, providing a more stable low-temperature environment for maintaining the superconducting state of superconducting coils. During disassembly, this connection assembly only requires stopping the refrigerator; as the temperature rises, the clamping member gradually loosens the second connector, allowing the cooling structure to detach from the heat sink. This significantly reduces workload, shortens maintenance cycles, and also reduces the probability of sealing failure and component damage in superconducting magnets, improving the stability and reliability of superconducting magnet equipment. Attached Figure Description

[0045] Figure 1 A schematic diagram of the structure of a refrigeration unit provided for an embodiment of the present invention;

[0046] Figure 2A schematic axial cross-sectional view of a refrigerator provided for an embodiment of the present invention;

[0047] Figure 3 A schematic diagram of the first cooling structure of the first connecting assembly of the refrigerator provided in an embodiment of the present invention, viewed radially;

[0048] Figure 4 A schematic diagram of the first cooling structure of the first connecting assembly of the refrigerator provided in an embodiment of the present invention, viewed along the axial direction;

[0049] Figure 5 for Figure 2 A magnified view of a portion of point A in the middle;

[0050] Figure 6 A schematic diagram of the radially oriented second cooling structure of the second connecting assembly of the refrigeration unit provided in an embodiment of the present invention;

[0051] Figure 7 A schematic diagram of the second cooling structure of the second connecting assembly of the refrigerator provided in an embodiment of the present invention, viewed along the axial direction;

[0052] Figure 8 for Figure 2 A magnified view of a portion of point B in the middle.

[0053] Explanation of reference numerals in the attached figures:

[0054] 10a. First connecting component;

[0055] 100a, First cooling structure; 110a, First connector of the first cooling structure; 111a, First connecting body; 112a, First connecting flange; 113a, First limiting flange; 114a, First assembly hole; 120a, Second connector of the first cooling structure; 121a, First sector-shaped connecting plate; 122a, First connecting hole; 130a, First flexible cooling component; 131a, First flexible cooling wire;

[0056] 200a, First clamping element; 210a, First clamping sleeve; 211a, First limiting hole;

[0057] 300a, First circumferential limiting component; 310a, First limiting post;

[0058] 10b. Second connecting component;

[0059] 100b, Second cooling structure; 110b, First connector of the second cooling structure; 111b, Second connecting body; 112b, Second connecting flange; 113b, Second limiting flange; 114b, Second assembly hole; 120b, Second connector of the second cooling structure; 121b, Second sector-shaped connecting plate; 122b, Second connecting hole; 130b, Second flexible cooling component; 131b, Second flexible cooling wire;

[0060] 200b, second clamping element; 210b, second clamping sleeve; 211b, second limiting hole;

[0061] 300b, Second circumferential limit assembly; 310b, Second limit post;

[0062] 20. Refrigeration unit body; 30. First cold head; 40. Second cold head; 50. First heat sink; 60. Second heat sink; 70. Support cylinder; 80. Connecting plate. Detailed Implementation

[0063] As mentioned in the background section, the cold head of the existing refrigeration unit and the heat sink of the cooled equipment are usually connected by bolts, which is troublesome to disassemble, greatly increases the workload of maintenance personnel, and prolongs the maintenance cycle. Especially in the field of superconducting magnets, this exacerbates the risk of superconducting magnets experiencing sealing failures, component damage, and other malfunctions, affecting the stability and reliability of superconducting magnet equipment.

[0064] To address this, the present invention provides a connecting assembly for a cold head of a refrigerator. This connecting assembly includes a cooling structure and a clamping member. The first connecting member of the cooling structure is fixedly fitted to the guide surface of the cold head, while the second connecting member is connected to the heat sink through a mounting hole. The clamping member is sleeved on the outer periphery of the second connecting member. As the temperature decreases, the clamping member presses the second connecting member, causing the inner wall of the second connecting member to press tightly against the outer wall of the heat sink. During disassembly, it is only necessary to stop the refrigerator from working. As the temperature rises, the clamping member gradually loosens the second connecting member, allowing the cooling structure to detach from the heat sink. This eliminates the need to disassemble internal components of superconducting magnet equipment such as vacuum cylinders and 50K radiation screens, significantly reducing the workload, shortening the maintenance cycle, and also reducing the probability of sealing failure and component damage in superconducting magnets, thereby improving the stability and reliability of superconducting magnet equipment.

[0065] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0066] This invention provides a connection assembly for a cold head of a refrigerator, which connects the cold head of the refrigerator to the cooling end of industrial equipment. The refrigerator can effectively reduce the temperature of a target object through a specific refrigeration principle, meeting the low-temperature requirements of different scenarios. For example, in the field of superconducting magnets, the refrigerator can cool the superconducting coils of superconducting magnets in superconducting magnet equipment, ensuring that the superconducting coils can maintain superconducting performance under low-temperature conditions. In the field of new energy (such as photovoltaics and battery manufacturing), the refrigerator can be used to cool furnaces, electrolytic cells, etc. In semiconductor and electronic equipment, processes such as semiconductor wafer manufacturing and integrated circuit packaging require precise temperature control; the refrigerator can cool the heat generated by semiconductor and electronic equipment during operation. This embodiment does not limit the application of the refrigerator to a single use.

[0067] like Figure 1 and Figure 2 As shown, a refrigeration unit typically includes multiple cold heads, such as a first cold head 30 and a second cold head 40. The first cold head 30 is connected to a first heat sink 50 via a first connecting assembly 10a, and the second cold head 40 is connected to a second heat sink 60 via a second connecting assembly 10b. Both the first connecting assembly 10a and the second connecting assembly 10b employ any of the aforementioned connecting assemblies for refrigeration unit cold heads. The structure of the first connecting assembly 10a will be described first below.

[0068] like Figure 2 and Figure 3 As shown, the first connecting assembly 10a includes a first cooling structure 100a and a first clamping member 200a. The first cooling structure 100a includes a first connector 110a and a second connector 120a connected sequentially along its length. One end of the first connector 110a of the first cooling structure away from the second connector 120a of the first cooling structure is used to fit and fix with the cooling surface of the first cold head 30. The second connector 120a of the first cooling structure is provided with a mounting hole for fixing and installing the first heat sink 50. The first clamping member 200a is sleeved on the outer periphery of the second connector 120a of the first cooling structure. As the temperature decreases, the first clamping member 200a shrinks inward along the radial direction of the first clamping member 200a and presses against the outer wall surface of the second connector 120a of the first cooling structure, so that the inner wall surface of the second connector 120a of the first cooling structure is pressed tightly against the outer wall surface of the first heat sink 50.

[0069] In this embodiment, the first connecting component 10a connects the first cold head 30 and the first heat sink 50 of the refrigerator through the first cooling structure 100a, thereby realizing the transfer of cold energy. The first connecting member 110a of the first cooling structure is fixedly attached to the guide surface of the first cold head 30, while the second connecting member 120a of the first cooling structure is connected to the first heat sink 50 through the mounting hole. Furthermore, the first pressing member 200a is sleeved on the outer periphery of the second connecting member 120a of the first cooling structure. As the temperature decreases, the first pressing member 200a presses the second connecting member 120a of the first cooling structure, so that the inner wall surface of the second connecting member 120a of the first cooling structure is pressed tightly against the outer wall surface of the first heat sink 50, reducing heat loss during the cooling process and improving the efficiency of cold energy conduction. Especially in the field of superconducting technology, this provides a more stable low-temperature environment for maintaining the superconducting state of the superconducting coil.

[0070] Furthermore, compared to the existing technology that uses bolts to connect the first cold head 30 and the first heat sink 50, this connecting component reduces the tedious operation of bolt disassembly and assembly. When repairing or replacing the first cold head 30 of the refrigerator, the staff does not need to disassemble the internal components of the superconducting magnet equipment such as the vacuum cylinder and radiation screen. They only need to stop the refrigerator from working. As the temperature rises, the first clamping member 200a gradually loosens the second connecting member 120a of the first cooling structure, which allows the first cooling structure 100a to detach from the first heat sink 50. This greatly reduces the workload, shortens the maintenance cycle, and also reduces the probability of sealing failure and component damage in the superconducting magnet, thus improving the stability and reliability of the superconducting magnet equipment.

[0071] Furthermore, the first cooling structure 100a of this connecting component can be assembled with most of the first cold heads 30 of the refrigeration unit, and has a wide range of applications.

[0072] It should be noted that, as Figure 3 As shown, to improve connection reliability, the first connector 110a and the second connector 120a of the first cooling structure are typically configured as rigid structures. Furthermore, the first cooling structure 100a also includes a first flexible cooling component 130a. Along the length of the first cooling structure 100a, the first flexible cooling component 130a is located between the first connector 110a and the second connector 120a, connecting them. The first flexible cooling component 130a is capable of deformation along a direction perpendicular to the length of the first cooling structure 100a.

[0073] As the temperature decreases, the first clamping member 200a contracts radially inward and presses against the outer wall of the second connector 120a of the first cooling structure. The second connector 120a of the first cooling structure contracts radially inward, so that the inner wall of the second connector 120a of the first cooling structure is pressed tightly against the outer wall of the first heat sink 50. The first flexible cooling member 130a bends inward from one end connected to the second connector 120a of the first cooling structure in a direction perpendicular to the length direction of the first cooling structure 100a.

[0074] In this embodiment, the first flexible cooling element 130a located between the first connector 110a and the second connector 120a of the first cooling structure can bend and deform with the radial contraction of the second connector 120a of the first cooling structure. This avoids the stress caused by the contraction of the second connector 120a of the first cooling structure, which could lead to the breakage or loosening of the first cooling structure 100a. At the same time, it maintains a continuous cooling path between the first connector 110a, the first flexible cooling element 130a, and the second connector 120a of the first cooling structure, ensuring that the cold energy is stably conducted to the first heat sink 50, and further optimizing the cooling effect.

[0075] Furthermore, compared to rigid connections, the deformation capability of the first flexible cooling component 130a can buffer the rigid force exerted on the first connecting component 110a (and the cooling surface of the first cold head 30) and the second connecting component 120a (and the first heat sink 50) of the first cooling structure when the second connecting component 120a of the first cooling structure contracts, thereby reducing the probability of mechanical damage such as cracks and wear caused by stress concentration in each component. Especially in the field of superconducting magnets, it can further ensure the reliability of superconducting magnet equipment.

[0076] In addition, the deformable nature of the first flexible cooling component 130a can tolerate a certain degree of assembly error (such as the coaxiality deviation between the first connector 110a and the second connector 120a of the first cooling structure), reducing assembly difficulty; during maintenance and disassembly, there is no need to strictly calibrate the position of each component, reducing secondary failures caused by insufficient assembly accuracy, further shortening the maintenance cycle and reducing the workload.

[0077] Specifically, such as Figure 3As shown, the first connecting member 110a of the first cooling structure includes a first connecting body 111a and a first connecting flange 112a. The first connecting body 111a is configured as a columnar structure extending along the length of the first cooling structure 100a, providing basic support for the cooling path. The first connecting flange 112a is connected to one end of the first connecting body 111a away from the first cooling structure, forming the end of the first connecting member 110a away from the first cooling structure, used to fit and fix with the cooling surface of the first cold head 30, improving the contact area and connection stability between the first cooling structure 100a and the cooling surface of the first cold head 30. It should be noted that the cooling surface of the first cold head 30 needs to be connected to the second cold head 40 at the same time as it is connected to the first connecting flange 112a of the first cooling structure 100a. Therefore, as Figure 2 As shown, the first connecting body 111a of the first connector 110a of the first cooling structure is hollow, which facilitates the passage of the first cold head 30 to connect with the second cold head 40.

[0078] Furthermore, the first flexible cooling component 130a includes multiple first flexible cooling wires 131a. One end of each of the multiple first flexible cooling wires 131a is fixedly connected to a corresponding part of the first connector 110a of the first cooling structure, and the other end is fixedly connected to a corresponding part of the second connector 120a of the first cooling structure. Specifically, the number of first flexible cooling wires 131a can be three, four, eight, ten, sixteen, or other numbers. Those skilled in the art can design it according to actual conditions and specific needs, and this embodiment does not limit it to a single number.

[0079] The second connector 120a of the first cooling structure includes a plurality of first sector-shaped connecting plates 121a spaced apart along the circumference, such as Figure 4 As shown, the second connector 120a of the first cooling structure includes four first sector-shaped connecting plates 121a spaced apart circumferentially. The four first sector-shaped connecting plates 121a together define a mounting hole. One end of each first sector-shaped connecting plate 121a near the first connector 110a of the first cooling structure is fixedly connected to the corresponding first flexible cooling wire 131a. Furthermore, a first connecting hole 122a is formed on the outer wall of each first sector-shaped connecting plate 121a. Fasteners (e.g., bolts) are used to fix the corresponding first connecting hole 122a through the radial direction of the first clamping member 200a and through the side wall of the first clamping member 200a, so that the corresponding first sector-shaped connecting plate 121a is fixedly connected to the first clamping member 200a, and the first clamping member 200a is pressed against the outer wall of the first sector-shaped connecting plate 121a. Of course, the second connector 120a of the first cooling structure also includes three, five, eight, ten or other numbers of first sector-shaped connecting plates 121a arranged circumferentially, and this embodiment does not limit this to a single one.

[0080] In this embodiment, the first clamping member 200a is fixedly connected to each of the first sector connecting plates 121a by fasteners, which can effectively limit the displacement of the first sector connecting plates 121a along the circumferential direction and prevent the first sector connecting plates 121a from misaligning during temperature changes.

[0081] When a single first sector-shaped connecting plate 121a or a single cooling wire of this first cooling structure 100a is damaged, the impact on the overall cooling path is small. The remaining components can still ensure the basic conduction of cold energy and connection stability. Especially in the field of superconducting magnets, it can reduce the risk of superconducting magnets losing superheat due to connection component failure. During maintenance, only the damaged parts can be replaced, avoiding the failure of the entire connection component due to local failure, which greatly reduces maintenance costs and equipment downtime.

[0082] It should be noted that any one of the first connector 110a, the second connector 120a, and the first flexible cold conductor 130a of the first cold-conducting structure is made of copper, oxygen-free copper, or silver. Copper, oxygen-free copper, and silver all have extremely high thermal conductivity. The first connector 110a, the second connector 120a, and the first flexible cold conductor 130a of the first cold-conducting structure made of any of the above materials can quickly transfer the cold energy of the first cold head 30, so that the loss of cold energy during the transfer process is minimal. For example, in a superconducting magnet device, the temperature of the first heat sink 50 can be quickly reduced to the low temperature range required by the superconducting magnet, ensuring that the superconducting coil can stably maintain the superconducting state. The first connector 110a, the second connector 120a, and the first flexible heat-conducting component 130a of the first heat-conducting structure are made of the aforementioned high thermal conductivity metal material. The first connector 110a and the first flexible heat-conducting component 130a, and the first flexible heat-conducting component 130a and the second connector 120a of the first heat-conducting structure can be welded together, thereby achieving high connection strength.

[0083] And, as Figure 2 and Figure 5 As shown, the first clamping member 200a is configured as a first clamping sleeve 210a, which is sleeved on the outer periphery of the plurality of first sector-shaped connecting plates 121a. Its annular structure can evenly transmit its radial contraction force to the outer wall surface of each first sector-shaped connecting plate 121a. Of course, the first clamping member 200a can also be configured as a spiral rod extending in a spiral shape around the outer periphery of the plurality of first sector-shaped connecting plates 121a. As the temperature decreases, the spiral rod contracts inward and compresses, thereby radially compressing the plurality of first sector-shaped connecting plates 121a.

[0084] Furthermore, in order to improve the assembly stability between the first cooling structure 100a and the first clamping member 200a, the first connecting assembly 10a also includes a first circumferential limiting assembly 300a, and the first clamping member 200a is connected to the first connecting member 110a of the first cooling structure through the first circumferential limiting assembly 300a.

[0085] The first connecting member 110a of the first cooling structure further includes a first limiting flange 113a. The first limiting flange 113a is connected to one end of the first connecting body 111a near the second connecting member 120a of the first cooling structure. One end of the multiple first flexible cooling wires 131a is fixedly connected to the alignment part of the first limiting flange 113a. Furthermore, the first circumferential limiting component 300a is disposed on the outer periphery of the multiple first flexible cooling wires 131a. One end of the first circumferential limiting component 300a is connected to the alignment part of the first limiting flange 113a, and the other end is connected to the corresponding part of the first clamping member 200a.

[0086] In this embodiment, the first circumferential limiting component 300a surrounds the outer periphery of the first flexible cooling wire 131a and is connected to the first connector 110a of the first cooling structure through the first limiting flange 113a. This directly restricts the relative circumferential rotation between the first clamping component 200a and the first connector 110a of the first cooling structure. At the same time, since the first clamping component 200a is fixed to the multiple first sector-shaped connecting plates 121a by fasteners, the risk of circumferential displacement of the multiple first sector-shaped connecting plates 121a is reduced, avoiding circumferential misalignment of components due to temperature changes or vibrations. This ensures that the mounting hole enclosed by the second connector 120a of the first cooling structure is always precisely aligned with the first heat sink 50, preventing damage caused by uneven stress on the first heat sink 50.

[0087] In addition, the first circumferential limiting component 300a can prevent the first flexible cooling wire 131a from being stretched or squeezed due to misalignment by limiting the circumferential displacement of each component, ensuring that each first flexible cooling wire 131a maintains a relatively stable connection state and cooling path; at the same time, it avoids the gap between the inner wall surface of the second connector 120a of the first cooling structure and the outer wall surface of the first heat sink 50 from increasing due to component misalignment, further reducing the loss of cold energy during the conduction process and ensuring the low-temperature stability required by the superconducting magnet.

[0088] Furthermore, a plurality of first limiting holes 211a are provided circumferentially at one end of the first clamping sleeve 210a near the first connecting member 110a of the first cooling structure, and a plurality of first assembly holes 114a corresponding to the plurality of first limiting holes 211a are provided circumferentially at one end of the first limiting flange 113a away from the first connecting flange 112a. The first circumferential limiting assembly 300a includes a plurality of first limiting posts 310a, which are provided circumferentially at intervals on the outer periphery of the first flexible cooling member 130a, and the plurality of first limiting posts 310a correspond one-to-one with the plurality of first limiting holes 211a.

[0089] Specifically, such as Figure 4 and Figure 5 As shown, four first limiting holes 211a are circumferentially spaced at one end of the first clamping sleeve 210a near the first connecting member 110a of the first cooling structure. Four corresponding first assembly holes 114a are provided at one end of the first limiting flange 113a away from the first connecting flange 112a. One end of each first limiting post 310a is embedded in the corresponding first limiting hole 211a, and the other end is connected to the alignment first assembly hole 114a of the first limiting flange 113a. Of course, this embodiment does not specifically limit the number of first limiting holes 211a on the first clamping sleeve 210a, the number of first assembly holes 114a on the first limiting flange 113a, and the number of first limiting posts 310a.

[0090] In this embodiment, the circumferential displacement of the first clamping sleeve 210a is prevented by the cooperation of the first limiting post 310a and the first limiting hole 211a. On the one hand, it can accurately constrain the circumferential position of the first sector connecting plate 121a, avoid the circumferential displacement of the first sector connecting plate 121a caused by temperature changes or equipment vibration, and ensure that the mounting hole enclosed by the second connector 120a of the first cooling structure is always accurately aligned with the first heat sink 50, preventing damage to the first heat sink 50 due to force displacement. On the other hand, it ensures that the pressure of the first clamping sleeve 210a on each first sector connecting plate 121a is consistent, causing all first sector connecting plates 121a to synchronously and radially contract, so that the inner wall surface of the second connector 120a of the first cooling structure is fully and tightly fitted with the outer wall surface of the first heat sink 50, reducing local fitting gaps and further reducing cold loss.

[0091] It should be noted that the first clamping component 200a can be made of polytetrafluoroethylene, perfluoroalkoxyalkane, or fluorinated ethylene propylene. Polytetrafluoroethylene, perfluoroalkoxyalkane, and fluorinated ethylene propylene have excellent low-temperature stability and can maintain good elasticity and structural integrity even at extremely low temperatures. They will not harden or crack due to temperature reduction. The first clamping component 200a made of the above materials can stably achieve radial shrinkage and clamping function as the temperature decreases.

[0092] To improve assembly stability, in this embodiment, an elastic gasket is pressed between the outer wall surface of the plurality of first sector-shaped connecting plates 121a and the inner wall surface of the first clamping sleeve 210a. The elastic gasket can undergo elastic deformation with the radial contraction of the first clamping sleeve 210a. On the one hand, it can fill the processing error or small unevenness between the outer wall surface of the first sector-shaped connecting plate 121a and the inner wall surface of the first clamping sleeve 210a, ensuring uniform pressure transmission. On the other hand, when temperature changes cause slight fluctuations in the contraction of the first clamping sleeve 210a, the elastic gasket can compensate for the pressure change through its own deformation, avoiding damage to components due to excessive local pressure or loosening of the assembly between the first clamping sleeve 210a and the first heat sink 50 due to insufficient pressure, thus always maintaining a stable clamping state of the first sector-shaped connecting plate 121a on the first heat sink 50. It should be noted that the thickness of the elastic gasket can be 0.1mm to 0.05mm. For example, the thickness of the elastic gasket can be 0.1mm, 0.02mm, 0.05mm or other thicknesses within the above range. This embodiment does not make specific limitations on this.

[0093] Furthermore, in this embodiment, indium sheets are provided and coated with low-temperature thermally conductive adhesive between the inner wall surfaces of the plurality of first sector-shaped connecting plates 121a and the outer wall surfaces of the first heat sink 50, and between the first connecting flange 112a and the cooling surface of the first cold head 30. The low-temperature thermally conductive adhesive can be a metal-based low-temperature thermally conductive adhesive made with copper powder, silver powder or nickel powder as thermally conductive filler and a low-temperature stable resin matrix (such as modified epoxy resin or silicone resin), or a ceramic-based low-temperature thermally conductive adhesive made with ceramic particles such as alumina, aluminum nitride, and boron nitride as filler and fluororubber or perfluoropolyether resin as matrix, or a carbon-based low-temperature thermally conductive adhesive made with graphene, carbon nanotubes or high thermal conductivity graphite powder as filler and low-temperature modified silicone rubber or polyimide resin as matrix. This embodiment does not specifically limit this.

[0094] In this embodiment, the indium sheet possesses excellent low-temperature ductility and thermal conductivity, allowing it to tightly fit into the minute gaps of the contact surface and eliminate air gaps (air has a low thermal conductivity and easily forms a bottleneck for cooling). Combined with the high thermal conductivity of the low-temperature thermally conductive adhesive, it further reduces the thermal resistance between the first sector-shaped connecting plate 121a and the first heat sink 50, and between the first connecting flange 112a and the cooling surface of the first cold head 30, achieving efficient heat transfer and reducing heat loss at the contact surface. It should be noted that the thickness of the indium sheet can be 0.05mm to 0.2mm, for example, 0.05mm, 0.1mm, 0.2mm, or other thicknesses within the above range; this embodiment does not impose a unique limitation on this.

[0095] Of course, the low-temperature thermally conductive adhesive not only improves thermal conductivity, but also has a certain sealing performance, which can prevent external impurities (such as dust and moisture) from entering the contact gap between the first sector-shaped connecting plate 121a and the first heat sink 50, and between the first connecting flange 112a and the first cold head 30. At the same time, the tight contact of the indium sheet can also block the intrusion of impurities, avoid contact surface corrosion and decreased thermal conductivity caused by the accumulation of impurities, or seal failure and component damage caused by impurities entering the vacuum cavity of the superconducting magnet, and further ensure the stability of the superconducting magnet equipment.

[0096] The structure of the second connecting component 10b is described below.

[0097] like Figure 2 and Figure 6 As shown, the second connecting assembly 10b includes a second cooling structure 100b and a second clamping member 200b. The second cooling structure 100b includes a first connecting member 110b and a second connecting member 120b connected sequentially along its length. One end of the first connecting member 110b of the second cooling structure away from the second connecting member 120b of the second cooling structure is used to fit and fix with the cooling surface of the second cold head 40. The second connecting member 120b of the second cooling structure is provided with a mounting hole for fixing and installing the second heat sink 60. The second clamping member 200b is sleeved on the outer periphery of the second connecting member 120b of the second cooling structure. As the temperature decreases, the second clamping member 200b shrinks inward along the radial direction of the first clamping member 200a and presses against the outer wall surface of the second connecting member 120b of the second cooling structure, so that the inner wall surface of the second connecting member 120b of the second cooling structure is pressed tightly against the outer wall surface of the second heat sink 60.

[0098] Similar to the first connecting component 10a of the second cooling structure, the second cooling structure 100b of the second connecting component 10b can have a second flexible cooling component 130b provided between the first connecting component 110b and the second connecting component 120b of the second cooling structure. The first connecting component 110b of the second cooling structure includes a second connecting body 111b and a second connecting flange 112b. The second connecting body 111b is configured as a columnar structure extending along the length direction of the second cooling structure 100b. Since the second cold head 40 does not need to be connected to other components, the second connecting body 111b of the first connecting component 110b of the second cooling structure is solid inside compared to the first cooling structure 100a, reducing the processing difficulty.

[0099] The second flexible cooling element 130b of the second cooling structure 100b also includes multiple second flexible cooling wires 131b, and the second connector 120b of the second cooling structure includes multiple second sector-shaped connecting plates 121b spaced circumferentially. Figure 7As shown, the second connector 120b of the second cooling structure includes eight second sector-shaped connectors 121b spaced apart along the circumference. One end of each of the multiple second flexible cooling wires 131b is fixedly connected to the corresponding part of the first connector 110b of the second cooling structure, and the other end is connected to the corresponding second sector-shaped connector 121b.

[0100] like Figure 7 and Figure 8 As shown, the second clamping member 200b is configured as a second clamping sleeve 210b. A second connecting hole 122b is also formed on the outer wall of each second sector-shaped connecting plate 121b. Fasteners are fixed to the corresponding second connecting hole 122b by passing radially through the side wall of the second clamping sleeve 210b. Elastic gaskets are pressed between the outer walls of the multiple second sector-shaped connecting plates 121b and the inner walls of the second clamping sleeve 210b. A second circumferential limiting group can also be provided between the second clamping member 200b and the second cooling structure 100b. In component 300b, the second clamping sleeve 210b has four second limiting holes 211b spaced circumferentially at one end of the first connecting member 110b near the second cooling structure, and the second limiting flange 113b has four corresponding second assembly holes 114b at one end away from the second connecting flange 112b. The second circumferential limiting assembly 300b includes four second limiting posts 310b, one end of each second limiting post 310b is embedded in the corresponding second limiting hole 211b, and the other end is connected to the alignment second assembly hole 114b of the second limiting flange 113b.

[0101] The specific design of the materials of the second cooling structure 100b and the second clamping member 200b, as well as the indium sheet and low-temperature thermally conductive adhesive disposed between the second connecting assembly 10b and the second cold head 40 and the second heat sink 60, will not be elaborated here.

[0102] This embodiment also discloses a refrigeration unit, such as... Figure 1 and Figure 2 As shown, the system includes a refrigerator body 20, a first cold head 30 and a second cold head 40 as described above. The first cold head 30 is connected to the first heat sink 50 via the first connecting assembly 10a, and the second cold head 40 is connected to the second heat sink 60 via the second connecting assembly 10b. In addition, the refrigerator also includes a support cylinder 70. One end of the support cylinder 70 is fixed and sealed to the refrigerator body 20, and the other end is fixed and sealed to the outer wall of the vacuum chamber.

[0103] The first cold head 30 extends into the support cylinder 70 from one end. The first cold-conducting surface on the first cold head 30 is fitted and fixed to the first connector 110a of the first cold-conducting structure. The first cold head 30 passes through the first cold-conducting structure 100a and is connected to the second cold head 40 located in the first heat sink 50 and extending from the other end of the support cylinder 70. The second cold-conducting surface on the second cold head 40 is fitted and fixed to the first connector 110b of the second cold-conducting structure.

[0104] In this type of refrigeration unit, the first cold head 30 is connected to the first heat sink 50 via the first connecting assembly 10a, and the second cold head 40 is connected to the second heat sink 60 via the second connecting assembly 10b, forming a two-stage refrigeration structure that can simultaneously provide stable low temperatures for heat sinks with different temperature requirements. Furthermore, both the first connecting assembly 10a and the second connecting assembly 10b utilize a cooling-conducting structure and clamping components, eliminating the need for disassembling numerous components as with traditional bolted connections. During maintenance, there is no need to damage the vacuum chamber (the support cylinder 70 is sealed to the vacuum chamber, maintaining its vacuum). Only after the cold head temperature rises does the clamping component loosen radially, directly separating the cold head (the upper-connected cooling-conducting structure) from the heat sink. This significantly reduces disassembly workload and shortens maintenance cycles. Especially in superconducting magnet equipment, it avoids seal failure and component damage caused by repeated disassembly and reassembly, reducing the risk of equipment malfunction.

[0105] Furthermore, a connecting plate 80 is provided between one end of the support cylinder 70 and the refrigerator body 20. One side of the connecting plate 80 along its thickness direction is attached to and fixedly connected to one end face of the support cylinder 70, and the other side is attached to and fixedly connected to the corresponding outer wall surface of the refrigerator body 20.

[0106] A sealing ring is provided between one side of the connecting plate 80 and one end face of the support cylinder 70, and between the other side of the connecting plate 80 and the corresponding outer wall surface of the refrigeration unit body 20.

[0107] One side of the connecting plate 80 along its thickness direction is attached to and fixedly connected to one end face of the support cylinder 70, and the other side is attached to the corresponding outer wall surface of the refrigeration unit body 20. This can evenly distribute the connection load between the support cylinder 70 and the refrigeration unit body 20 (such as the weight of the support cylinder 70 and the vibration load during the operation of the cold head) to a larger contact area, avoiding deformation of the port of the support cylinder 70 or damage to the outer wall surface of the refrigeration unit body 20 caused by local stress concentration. Especially in low temperature environments, metal parts (support cylinder 70, refrigeration unit body 20) are prone to stress due to thermal expansion and contraction. The buffering effect of the connecting plate 80 can reduce the impact of stress on the sealing surface, prevent the sealing ring from being squeezed and damaged due to component deformation, and extend the service life of the sealing structure.

[0108] It should be noted that vacuum grease can also be applied to the outer surface of the sealing ring. Vacuum grease has excellent wettability and fluidity, which can tightly fill the tiny pores between the sealing ring and the mating surface (such as microscopic irregularities left over from component processing, or minute gaps formed after the sealing ring is compressed), preventing a decrease in the vacuum level of the vacuum chamber and ensuring the stability of the high vacuum environment required by the superconducting magnet. Of course, for better sealing, the vacuum grease can be a high-vacuum grease suitable for high vacuum to ultra-high vacuum environments.

[0109] The following example illustrates the assembly and disassembly process of a refrigerator installed on a superconducting magnet.

[0110] A superconducting magnet device typically includes a vacuum chamber, a radiation screen and a superconducting magnet disposed within the vacuum chamber. The radiation screen divides the inner cavity of the vacuum chamber into a first chamber and a second chamber that are independently disposed of. The superconducting magnet is located in the first chamber.

[0111] The other end of the support cylinder 70 of the refrigeration unit is connected to the outer wall of the second chamber, and the first heat sink 50 is fixedly connected to the radiation screen, while the second heat sink 60 is fixedly connected to the end plate on the superconducting magnet.

[0112] The refrigerator of this superconducting magnet device is connected to the radiation screen via a first heat sink 50. The first cold head 30 can provide a suitable low temperature to the radiation screen through the first connecting component 10a, thereby suppressing the impact of radiative heat transfer on the first chamber. The second cold head 40 can provide an even lower target low temperature to the superconducting magnet through the second connecting component 10b, ensuring that the superconducting coils in the superconducting magnet maintain a stable superconducting state. This staged cooling method precisely matches the different low temperature requirements of the radiation screen and the superconducting magnet, avoiding energy waste or insufficient cooling caused by a single cooling mode, and ensuring the efficient operation of the superconducting magnet device.

[0113] When assembling the refrigerator in this superconducting magnet device, the support cylinder 70 needs to be connected to the outer wall of the second chamber first. Then, the first cold head 30 of the refrigerator is assembled with the first connecting component 10a, and the second cold head 40 is assembled with the second connecting component 10b. The first cold head 30 and the second cold head 40 are then inserted into the support cylinder 70, so that the second connecting component 120a of the first cooling structure is connected to the first heat sink 50, and the second connecting component 120b of the second cooling structure is connected to the second heat sink 60. Finally, the refrigerator body 20 is connected to the support cylinder 70 through the connecting plate 80.

[0114] After the refrigerator is assembled, the airtightness of the vacuum chamber is checked, and then the refrigerator starts to operate, so that the first cold head 30 transfers cold energy to the radiation screen and the second cold head 40 transfers cold energy to the end plate on the superconducting magnet.

[0115] When the refrigeration unit needs to be repaired or replaced, there is no need to damage the overall structure of the vacuum chamber (especially no need to disassemble the first chamber). A suitable amount of nitrogen is introduced into the vacuum chamber. After the temperature inside the chamber rises to room temperature, the connection between the support cylinder 70 and the refrigeration unit body 20 is disconnected. As the temperature rises, the first clamping member 200a and the second clamping member 200b are relaxed radially, directly separating the first cooling structure 100a from the first heat sink 50 and the second cooling structure 10b from the second heat sink 60, greatly reducing the amount of disassembly and assembly work.

[0116] It should be noted that, in addition to the specific embodiments described above, those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with the embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a deep understanding of the invention, many specific details are included in the above description, and the invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0117] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0118] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of the invention is usually placed in during use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0119] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0120] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" 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 of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0121] While the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the invention to these descriptions. Various changes in form and detail can be made by those skilled in the art, including several simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

1. A connection assembly for a cold head of a refrigerator, characterized in that The application relates to a connecting assembly for connecting a cold head and a heat sink. The connecting assembly comprises a cold lead structure and a compression member. The cold lead structure comprises a first connecting member and a second connecting member connected in sequence along the length direction of the cold lead structure.

2. The connection assembly for a cold head of a refrigerator according to claim 1, characterized in that The first connecting member is used for being fixedly attached to the cold lead surface of the cold head. The second connecting member is provided with a mounting hole for fixedly mounting the heat sink.

3. The connection assembly for a cold head of a refrigerator according to claim 2, characterized in that The compression member is sleeved on the outer circumferential side of the second connecting member. The compression member is gradually loosened along with the temperature rise. The cold lead structure is separated from the heat sink.

4. The connection assembly for a cold head of a refrigerator according to claim 3, characterized in that The cold lead structure further comprises a flexible cold lead member. The flexible cold lead member is located between the first connecting member and the second connecting member along the length direction of the cold lead structure and connects the first connecting member and the second connecting member. The flexible cold lead member can be deformed along the direction perpendicular to the length direction of the cold lead structure. The first connecting member comprises a connecting body and a connecting flange. The connecting body is arranged as a columnar structure extending along the length direction of the cold lead structure. The connecting flange is connected to the end of the connecting body away from the second connecting member and constitutes the end of the first connecting member away from the second connecting member. The flexible cold lead member comprises a plurality of flexible cold lead wires. One end of the flexible cold lead wires is fixedly connected to the corresponding part of the first connecting member. The other end of the flexible cold lead wires is fixedly connected to the corresponding part of the second connecting member. The second connecting member comprises a plurality of fan-shaped connecting plates arranged at intervals along the circumferential direction of the second connecting member. The plurality of fan-shaped connecting plates jointly define the mounting hole. Each fan-shaped connecting plate is fixedly connected to the corresponding flexible cold lead wire at the end close to the first connecting member. A connecting hole is further formed on the outer wall surface of each fan-shaped connecting plate. A fastener penetrates the side wall of the compression member along the radial direction of the compression member and is fixed in the corresponding connecting hole. The corresponding fan-shaped connecting plate is fixedly connected to the compression member. The compression member is tightly attached to the outer wall surface of the fan-shaped connecting plate. The connecting assembly further comprises a circumferential limiting assembly. The compression member is connected to the first connecting member through the circumferential limiting assembly. The circumferential limiting assembly comprises a plurality of limiting members arranged at intervals along the circumferential direction of the first connecting member. Each limiting member is arranged on the outer wall surface of the first connecting member. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. 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The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact with the corresponding fan-shaped connecting plate. The limiting member is arranged to be in contact The first connector further includes a limiting flange, which is connected to one end of the connecting body near the second connector. One end of the plurality of flexible cooling wires is fixedly connected to the alignment part of the limiting flange. Furthermore, the circumferential limiting component is disposed on the outer periphery of the plurality of flexible cooling wires. One end of the circumferential limiting component is connected to the alignment part of the limiting flange, and the other end is connected to the corresponding part of the clamping member.

5. The connection assembly for a cold head of a refrigerator according to claim 4, characterized in that The clamping element is configured as a clamping sleeve, which is sleeved on the outer periphery of the plurality of sector-shaped connecting plates; and... The clamping sleeve is provided with a plurality of limiting holes at intervals along the circumference at one end near the first connector. The circumferential limiting component includes a plurality of limiting posts. The plurality of limiting posts are provided at intervals along the circumference of the flexible cooling component on the outer circumference side of the flexible cooling component. The plurality of limiting posts correspond one-to-one with the plurality of limiting holes. One end of each limiting post is embedded in the corresponding limiting hole, and the other end is connected to the alignment part of the limiting flange.

6. The connection assembly for a cold head of a refrigerator according to claim 5, characterized in that An elastic gasket is pressed between the outer wall surface of the plurality of fan-shaped connecting plates and the inner wall surface of the clamping sleeve; An indium sheet is provided between the inner wall surface of the plurality of fan-shaped connecting plates and the outer wall surface of the heat sink, and between the connecting flange and the cooling surface of the cold head, and coated with low-temperature thermally conductive adhesive.

7. A connection assembly for a cold head of a refrigerator according to any one of claims 2 to 6, characterized in that The first connector, the second connector, and the flexible cooling component are all made of copper, oxygen-free copper, or silver, and the clamping component is made of polytetrafluoroethylene, perfluoroalkoxyalkane, or fluorinated ethylene propylene.

8. A refrigerator characterized by comprising: The system includes a refrigerator body, a first cold head, a second cold head, a first connecting assembly, and a second connecting assembly. One end of the first cold head is connected to the refrigerator body, and the other end is connected to the second cold head. The first cold head is connected to a first heat sink via the first connecting assembly, and the second cold head is connected to a second heat sink via the second connecting assembly. Both the first and second connecting assemblies are using the connecting assemblies for refrigerator cold heads as described in any one of claims 1 to 7. The first connecting assembly has a first cooling structure and a first clamping member, while the second connecting assembly has a second cooling structure and a second clamping member. The refrigerator also includes a support cylinder, one end of which is fixedly and sealed to the refrigerator body, and the other end is fixedly and sealed to the outer wall of the vacuum chamber; wherein... The first cold head extends into the support cylinder from one end. The first cold head is provided with a first cooling surface. The first cooling surface is fitted and fixed to the first connector of the first cooling structure. The first connector and the first heat sink of the first cooling structure are hollow structures. The first cold head passes through the first cooling structure and is connected to a second cold head located in the first heat sink and extending from the other end of the support cylinder. The second cold head is provided with a second cooling surface. The second cooling surface is fitted and fixed to the first connector of the second cooling structure.

9. The refrigerator of claim 8, wherein, A connecting plate is provided between one end of the support cylinder and the refrigerator body. One side of the connecting plate along its thickness direction is attached to and fixedly connected to one end face of the support cylinder, and the other side is attached to and fixedly connected to the corresponding outer wall surface of the refrigerator body.

10. The refrigerator of claim 9, wherein, A sealing ring is provided between one side of the connecting plate and one end of the support cylinder, and between the other side of the connecting plate and the corresponding outer wall of the refrigerator body; and the outer surface of the sealing ring is coated with vacuum silicone grease.

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