A superconducting coil suspension structure

Abstract

The application discloses a superconducting coil suspension structure and relates to the technical field of superconducting coils. The structure comprises a Dewar assembly, a cold mass and a plurality of pull rod assemblies. The plurality of pull rod assemblies are arranged in a vacuum interlayer between the Dewar assembly and the cold mass, the pull rod seats of the pull rod assemblies are respectively installed on a first upper end plate, a first lower end plate, a second upper end plate and a second lower end plate, the inclined screws are obliquely arranged and the two ends of the inclined screws respectively pass through the corresponding pull rod seats and are locked by adjusting nuts, so that a single obliquely arranged inclined screw can simultaneously provide axial and radial constraints, thereby significantly reducing the number of pull rod assemblies and the types of components, making the overall suspension structure more simple and compact, effectively reducing the occupied space of the vacuum interlayer, and only needing to pass the inclined screws through the pull rod seats and lock the inclined screws by the adjusting nuts during assembly to complete the installation and pre-tightening, so that the assembly process is simple and does not need to use a complex cone cylinder assembly, thereby reducing the manufacturing and assembly costs.

Description

Technical Field

[0001] This invention relates to the field of superconducting coil technology, and in particular to a superconducting coil suspension structure. Background Technology

[0002] With the continuous maturation of superconducting technology, superconducting magnets have been widely used in fields such as medicine, transportation, energy, information, and scientific research. Cryogenic superconducting magnets typically consist of a Dewar assembly at approximately 300K room temperature and a cold mass at approximately 4.2K liquid helium temperature. The cold mass generally comprises a superconducting coil, a coil frame, and upper and lower end plates, and is connected to the Dewar assembly via a suspension support structure. Due to the significant temperature difference between the room temperature and cryogenic regions, the suspension support structure not only needs to ensure sufficient structural strength to prevent the superconducting coil from becoming unstable or shifting under various operating conditions, but also must minimize the heat-conducting area, extend the heat transfer path, and use materials with low thermal conductivity to reduce heat leakage to the cryogenic cold mass.

[0003] Currently, existing technologies for supporting superconducting magnets often employ a combination of radial and axial tie rods, or a conical assembly structure with multiple conical cylinders nested sequentially from the inside out. However, using a combination of axial and radial tie rods results in a large number of tie rod assemblies, complex structure, and a large space occupied in the vacuum interlayer, making it difficult to reduce the overall size and footprint of the magnet. Furthermore, the compact vacuum interlayer space makes it difficult to guarantee the effective length of the tie rods, leading to short heat transfer paths and significant heat leakage. Additionally, the different stiffnesses of the axial and radial tie rods can easily cause uneven stress on the superconducting coil. While using conical assemblies can extend the heat transfer path, their structure is complex, manufacturing and assembly are cumbersome, and costs are high. Therefore, there is an urgent need for a superconducting coil suspension method that is structurally simple, has reasonable stress distribution, excellent thermal insulation performance, and a small footprint. Summary of the Invention

[0004] This invention provides a superconducting coil suspension structure that can solve the problems of complex structure, large vacuum interlayer space occupation, cumbersome assembly and high cost in the prior art.

[0005] A superconducting coil suspension structure includes a Dewar assembly, a cold mass, and multiple sets of tie rod assemblies. The multiple sets of tie rod assemblies are disposed within a vacuum interlayer between the Dewar assembly and the cold mass. The Dewar assembly includes a Dewar body and a first upper end plate and a first lower end plate disposed above and below it. The cold mass is disposed within the Dewar assembly and includes a second upper end plate and a second lower end plate. The tie rod assembly includes a tie rod seat, a helical screw, and an adjusting nut. The tie rod seat is respectively mounted on the first upper end plate, the first lower end plate, the second upper end plate, and the second lower end plate. The helical screw is inclined, with its two ends passing through the corresponding tie rod seat and locked by the adjusting nut to provide both axial and radial constraints.

[0006] The superconducting coil suspension structure provided by this invention has, but is not limited to, the following beneficial effects compared to existing technologies: This superconducting coil suspension structure uses multiple sets of tie rod assemblies set within the vacuum interlayer between the Dewar assembly and the cold mass. The tie rod seats of the tie rod assemblies are respectively mounted on the first upper end plate, the first lower end plate, the second upper end plate, and the second lower end plate. The inclined screw is set at an angle, with both ends passing through the corresponding tie rod seats and locked by adjusting nuts. Therefore, a single inclined screw can provide axial and radial constraints simultaneously, thereby significantly reducing the number of tie rod assemblies and the types of parts, making the overall suspension structure simpler and more compact, effectively reducing the space occupied by the vacuum interlayer. During assembly, installation and pre-tightening can be completed simply by passing the inclined screw through the tie rod seat and locking it with adjusting nuts. The assembly process is simple and does not require the use of complex conical cylinder assemblies, reducing manufacturing and assembly costs.

[0007] Furthermore, multiple grooves are provided on the first upper end plate, the first lower end plate, the second upper end plate, and the second lower end plate, and the pull rod seat is embedded in the groove and detachably connected by fixing bolts.

[0008] Furthermore, multiple sets of the pull rod assemblies are evenly and symmetrically distributed in the circumferential direction of the Dewar assembly.

[0009] Furthermore, the tie rod assembly located between the first upper end plate and the second upper end plate and the tie rod assembly located between the first lower end plate and the second lower end plate are arranged symmetrically above and below the horizontal mid-surface of the cold mass, and are arranged in a cross pattern in a radial plane perpendicular to the circumferential direction, forming a space truss structure.

[0010] Furthermore, the tie rod seat is provided with a mounting hole, the axis of which is inclined to the plane of the end plate, and the inclination angle is consistent with the inclination angle of the inclined screw.

[0011] Furthermore, the pull rod seat includes a first seat body and a second seat body. The first seat body is respectively mounted on a first upper end plate and a first lower end plate, and the second seat body is respectively mounted on a second upper end plate and a second lower end plate. Along the radial direction of the Dewar assembly, the first seat body is located radially outside the second seat body, and the inclined screw extends obliquely from the first seat body to the second seat body.

[0012] Furthermore, the inclined screw includes a smooth section in the middle and external thread sections at both ends. The diameter of the smooth section is smaller than the outer diameter of the external thread section and larger than the thread root diameter of the external thread section.

[0013] Furthermore, a heat-insulating pad is provided between the pull rod seat and the bottom surface of the groove. The heat-insulating pad is used to block the heat directly conducted between the Dewar assembly and the cold mass through the pull rod seat.

[0014] Furthermore, spherical washers are provided between the two ends of the inclined screw and the adjusting nut.

[0015] Furthermore, the inclined screw is a titanium alloy screw. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a superconducting coil suspension structure according to an embodiment of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of a superconducting coil suspension structure according to an embodiment of the present invention. Figure 2 ; Figure 3 This is a left view of a superconducting coil suspension structure according to an embodiment of the present invention; Figure 4 This is a right view of a superconducting coil suspension structure according to an embodiment of the present invention; Figure 5 for Figure 1 Schematic diagram of the tie rod assembly; Figure 6 for Figure 1 A schematic diagram of the structure of the Dewar body.

[0017] Explanation of reference numerals in the attached figures: 1. Dewar assembly; 2. Cold mass; 3. Tie rod assembly; 4. Groove; 5. Fixing bolt; 6. Insulating gasket; 11. Dewar body; 12. First upper end plate; 13. First lower end plate; 21. Second upper end plate; 22. Second lower end plate; 31. Tie rod seat; 32. Diagonal screw; 33. Adjusting nut; 34. Mounting hole; 35. Spherical washer; 311. First seat; 312. Second seat; 321. Smooth rod section; 322. External thread section. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application are described clearly and completely below with reference to the accompanying drawings. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," "comprise," etc., in the specification, claims, and accompanying drawings of this application are open-ended terms, indicating that a method comprises one or more steps, or an apparatus comprises one or more elements, but do not exclude the inclusion of other steps or elements. The terms "first," "second," etc., in the specification, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or primary / secondary relationship. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0023] like Figure 1-4As shown, an embodiment of the present invention provides a superconducting coil suspension structure, including a Dewar assembly 1, a cold mass 2, and multiple sets of tie rod assemblies 3. The multiple sets of tie rod assemblies 3 are disposed in a vacuum interlayer between the Dewar assembly 1 and the cold mass 2. The Dewar assembly 1 includes a Dewar body 11 and a first upper end plate 12 and a first lower end plate 13 disposed above and below it. The cold mass 2 is disposed inside the Dewar assembly 1 and includes a second upper end plate 21 and a second lower end plate 22. The tie rod assembly 3 includes a tie rod seat 31, a helical screw 32, and an adjusting nut 33. The tie rod seat 31 is respectively installed on the first upper end plate 12, the first lower end plate 13, the second upper end plate 21, and the second lower end plate 22. The helical screw 32 is inclined and its two ends pass through the corresponding tie rod seat 31 and are locked by the adjusting nut 33 to provide axial and radial constraints simultaneously.

[0024] In this embodiment, multiple sets of tie rod assemblies 3 are arranged in the vacuum interlayer between the Dewar assembly 1 and the cold mass 2. The tie rod seats 31 of the tie rod assembly 3 are respectively installed on the first upper end plate 12, the first lower end plate 13, the second upper end plate 21, and the second lower end plate 22. The inclined screw 32 is inclined and its two ends pass through the corresponding tie rod seats 31 and are locked by the adjusting nut 33. Therefore, a single inclined screw 32 can provide axial and radial constraints at the same time, without the need to set axial and radial tie rods separately as in the prior art. This significantly reduces the number of tie rod assemblies 3 and the types of parts, making the overall suspension structure simpler and more compact, effectively reducing the space occupied by the vacuum interlayer. During assembly, it is only necessary to pass the inclined screw 32 through the tie rod seat 31 and lock it by the adjusting nut 33 to complete the installation and pre-tightening. The assembly process is simple and does not require the use of complex cone cylinder assemblies, reducing manufacturing and assembly costs. This solves the problems of complex structure, large space occupation in vacuum interlayer, cumbersome assembly, and high cost in the prior art.

[0025] like Figure 1 and Figure 6 As shown, multiple grooves 4 are provided on the first upper end plate 12, the first lower end plate 13, the second upper end plate 21, and the second lower end plate 22. The pull rod seat 31 is embedded in the groove 4 and can be detachably connected by fixing bolts 5.

[0026] In this embodiment, since multiple grooves 4 are provided on the first upper end plate 12, the first lower end plate 13, the second upper end plate 21, and the second lower end plate 22, the tie rod seat 31 is embedded in the groove 4 and detachably connected by the fixing bolt 5. Therefore, the groove 4 can position and limit the tie rod seat 31, so that the shear load on the tie rod seat 31 is mainly borne by the mating surface of the groove 4, and the fixing bolt 5 mainly plays the role of locking and fixing, thereby reducing the shear force on the fixing bolt 5 and improving the connection reliability. At the same time, the axis of the mounting hole 34 is consistent with the inclination angle of the inclined screw 32, and the inclined screw 32 can be directly inserted along its own axis and locked by the adjusting nut 33. No additional angle adjustment is required during assembly, which simplifies the assembly process.

[0027] like Figure 1 and Figure 2 As shown, multiple sets of tie rod assemblies 3 are evenly and symmetrically distributed in the circumferential direction of the Dewar assembly 1.

[0028] In this embodiment, since multiple sets of tie rod assemblies 3 are evenly and symmetrically distributed in the circumferential direction of the Dewar assembly 1, the horizontal component force generated by the inclined screw 32 in each set of tie rod assemblies 3 cancels each other in the circumferential direction. After the axial component force is superimposed, it is balanced with the gravity of the cold mass 2, so that the cold mass 2 is uniformly constrained in the axial, radial and circumferential directions. This avoids uneven force, local stress concentration and displacement of the cold mass 2 caused by uneven distribution of tie rods or differences in stiffness. Thus, while ensuring stable suspension, the number of tie rod assemblies 3 is reduced, the overall structure is simplified, the utilization rate of vacuum interlayer space is improved and the assembly difficulty and cost are reduced. This solves the problems of complex structure, large vacuum interlayer space occupation, cumbersome assembly and high cost in the prior art.

[0029] like Figure 1 and Figure 2 As shown, the tie rod assembly 3 located between the first upper end plate 12 and the second upper end plate 21 and the tie rod assembly 3 located between the first lower end plate 13 and the second lower end plate 22 are symmetrically arranged above and below the horizontal mid-surface of the cold mass 2, and are arranged in a cross pattern in a radial plane perpendicular to the circumferential direction, forming a space truss structure.

[0030] In this embodiment, by symmetrically arranging the upper and lower components and forming a spatial truss structure, the stress state and thermal contraction deformation of the upper and lower tie rod assemblies 3 can be matched. When the cold mass 2 drops from room temperature to the liquid helium temperature range, the contraction amount and angle change trend of the upper and lower inclined screws 32 are consistent, which can effectively avoid the tilting of the cold mass 2 or the rapid change of local preload due to uneven contraction, so that the cold mass 2 always remains stably suspended. At the same time, the cross arrangement makes the upper and lower inclined screws 32 form an X-shaped spatial truss in the radial plane, which can effectively resist the cold mass 2 under operating, transportation, vibration or quenching conditions. The axial load, radial load, overturning moment, and torsional moment generated significantly improve the overall stiffness and dynamic stability of the suspension structure, preventing displacement or instability of the cold mass 2. In addition, the space truss structure allows the inclined screw 32 to mainly bear tensile loads along its own axis, reducing additional bending moment and shear stress, improving connection reliability and service life. Furthermore, the symmetrical and cross arrangement can reduce the number of tie rod assemblies 3 and connection nodes while ensuring stable suspension, making the overall structure simpler and more compact, reducing the space occupied by the vacuum interlayer, facilitating assembly and preload adjustment, and reducing manufacturing and assembly costs.

[0031] like Figure 1 and Figure 5 As shown, the tie rod seat 31 is provided with a mounting hole 34. The axis of the mounting hole 34 is inclined to the plane of the end plate, and the inclination angle is consistent with the inclination angle of the inclined screw 32.

[0032] In this embodiment, since the tie rod seat 31 is provided with a mounting hole 34, the axis of the mounting hole 34 is inclined to the plane of the end plate, and the inclination angle is consistent with the inclination angle of the inclined screw 32. Therefore, the inclined screw 32 can pass directly through the mounting hole 34 along its own axis direction without bending at the tie rod seat 31 or setting a complex angle adjustment structure. This allows the tension of the inclined screw 32 to be transmitted along the axis, avoiding the generation of additional bending moment and shear stress. This ensures that the inclined screw 32 mainly bears the tensile load, improving the connection reliability and service life. At the same time, the matching inclination angle makes the tie rod seat 31 compact, which facilitates the insertion of the inclined screw 32 and the locking of the adjusting nut 33. During assembly, there is no need to adjust the angle between the inclined screw 32 and the mounting hole 34, which simplifies the assembly process, reduces the number of parts and the space occupied by the vacuum interlayer, thereby reducing manufacturing and assembly costs.

[0033] like Figure 3 and Figure 4 As shown, the pull rod seat 31 includes a first seat body 311 and a second seat body 312. The first seat body 311 is respectively mounted on the first upper end plate 12 and the first lower end plate 13, and the second seat body 312 is respectively mounted on the second upper end plate 21 and the second lower end plate 22. Along the radial direction of the Dewar assembly 1, the first seat body 311 is located radially outside the second seat body 312, and the inclined screw 32 extends obliquely from the first seat body 311 to the second seat body 312.

[0034] In this embodiment, by forming an inner and outer staggered arrangement in the radial direction with the first seat 311 and the second seat 312, the inclined screw 32 can connect the first upper end plate 12 or the first lower end plate 13 on the room temperature side and the second upper end plate 21 or the second lower end plate 22 on the low temperature side at a reasonable tilt angle within the limited vacuum interlayer space between the Dewar assembly 1 and the cold mass 2. A single inclined screw 32 can provide both axial and radial constraints simultaneously, eliminating the need for separate axial and radial tie rods. This reduces the number of tie rod assemblies 3 and connection nodes, simplifies the overall suspension structure, and reduces the space occupied in the vacuum interlayer. Simultaneously, the inclined screw 32, from its radial direction... The first seat 311 extends outward and the second seat 312 extends radially inward, so that the tension direction of the inclined screw 32 forms a reasonable angle with the gravity direction of the cold mass 2. The axial component of the screw is superimposed and balances the gravity of the cold mass 2. The radial component cancels each other out in the circumferential direction, ensuring that the cold mass 2 is subjected to uniform force and is suspended stably. In addition, this inner and outer seat layout facilitates the uniform and symmetrical arrangement of multiple sets of tie rod assemblies 3 in the circumferential direction, avoiding interference between the inclined screw 32 and the cold mass 2 body. It also facilitates the insertion of the inclined screw 32 and the tightening of the adjusting nut 33 during assembly, without the need for complex centering tooling, simplifying the assembly process and reducing manufacturing and assembly costs.

[0035] Specifically, the first base 311 is located on the radially outer side and the second base 312 is located on the radially inner side, so that the length and tilt angle of the inclined screw 32 can be optimized according to the axial and radial spacing between the Dewar assembly 1 and the cold mass 2. While ensuring structural strength, the heat transfer path is extended and the heat conduction cross-sectional area is reduced, thereby reducing heat leakage from the room temperature end to the cold mass 2 in the liquid helium temperature range and improving the operational stability of the superconducting magnet.

[0036] like Figure 3 and Figure 5 As shown, the inclined screw 32 includes a smooth section 321 located in the middle and external thread sections 322 located at both ends. The diameter of the smooth section 321 is smaller than the outer diameter of the external thread section 322 and larger than the thread root diameter of the external thread section 322.

[0037] In this embodiment, by making the cross-sectional area of ​​the smooth rod section 321 smaller than the cross-sectional area corresponding to the outer diameter of the external thread section 322, the thermal conductivity of the main heat transfer path in the middle is effectively reduced while ensuring the tensile load-bearing capacity of the inclined screw 32. This reduces solid heat leakage from the room temperature Dewar assembly 1 to the cold mass 2 in the liquid helium temperature zone. At the same time, the diameter of the smooth rod section 321 is larger than the thread root diameter of the external thread section 322, making the cross-sectional area of ​​the smooth rod section 321 larger than the minimum effective load-bearing cross-section of the thread section. This prevents the smooth rod section 321 from becoming a weak point in strength, ensuring that the inclined screw 32 will not yield or break before the thread section when mainly bearing tensile loads under the action of preload and gravity of the cold mass 2, thus improving the safety and reliability of the suspension structure.

[0038] Specifically, the smooth rod section 321 has a smooth, threadless surface, which reduces stress concentration and thread machining length. The external thread section 322 is only set at both ends where it mates with the adjusting nut 33, which satisfies the requirements for preload application and locking, while reducing the amount of thread machining and material cost. Furthermore, the smooth rod section 321 can be set to a longer length to extend the heat transfer path and further reduce heat leakage, thereby achieving a balance between strength, heat insulation, processing, and cost.

[0039] like Figure 1 and Figure 6 As shown, a heat insulation pad 6 is provided between the pull rod seat 31 and the bottom surface of the groove 4. The heat insulation pad 6 is used to block the heat directly conducted between the Dewar assembly 1 and the cold mass 2 through the pull rod seat 31.

[0040] In this embodiment, the heat transfer between the Dewar assembly 1 and the cold mass 2 via the pull rod seat 31 is blocked by the heat insulation pad 6. Therefore, when the Dewar assembly 1 is at room temperature and the cold mass 2 is in the liquid helium temperature range, the pull rod seat 31, as a metal component connecting the first upper end plate 12 or the first lower end plate 13 to the second upper end plate 21 or the second lower end plate 22, will form a solid thermal bridge that conducts heat from the room temperature end to the low temperature end when it is in direct contact with the bottom surface of the groove 4. The heat insulation pad 6, made of a low thermal conductivity material and placed between the pull rod seat 31 and the bottom surface of the groove 4, can significantly increase the thermal resistance of the contact interface, blocking or greatly reducing the path of heat transfer directly to the cold mass 2 via the pull rod seat 31, thereby reducing the overall heat leakage of the cold mass 2 and reducing the amount of liquid helium evaporation, which is beneficial. To maintain the low-temperature environment required for superconducting coils and improve the stability and economy of superconducting magnet operation; at the same time, the heat insulation pad 6 is only set between the tie rod seat 31 and the bottom surface of the groove 4, without changing the positioning and limiting relationship of the tie rod seat 31 embedded in the groove 4. The mating surface of the groove 4 can still bear the shear load, the fixing bolt 5 can still reliably lock the tie rod seat 31, and the inclined screw 32 still mainly bears the tensile load. Therefore, it will not weaken the load-bearing capacity and connection reliability of the suspension structure. Moreover, the heat insulation pad 6 has a simple structure, thin thickness, and is easy to process and assemble. It can also compensate for the unevenness of the contact between the tie rod seat 31 and the bottom surface of the groove 4, making the force more uniform. There is no need to add complex parts or change the original assembly process, thereby effectively reducing heat leakage while simplifying the structure, facilitating assembly and reducing costs.

[0041] like Figure 3 and Figure 5 As shown, spherical washers 35 are provided between the two ends of the inclined screw 32 and the adjusting nut 33, and the inclined screw 32 is a titanium alloy screw.

[0042] In this embodiment, by setting a spherical washer 35, the angular deviation between the end face of the inclined screw 32 and the adjusting nut 33 when the inclined screw 32 is tilted can be automatically adapted, so that the preload applied by the adjusting nut 33 is uniformly transmitted along the axial direction of the inclined screw 32. This avoids the introduction of additional bending moment and local shear stress in the inclined screw 32 due to non-perpendicular end face or assembly deviation, ensuring that the inclined screw 32 mainly bears tensile load, improving connection reliability and fatigue life. At the same time, it is convenient to apply and adjust the preload by turning the adjusting nut 33, and no high-precision centering or additional angle adjustment is required during assembly, simplifying the assembly process. The inclined screw 32 is made of titanium alloy. Made of titanium alloy, the thermal conductivity of which is much lower than that of stainless steel, it can effectively reduce solid heat leakage from the room temperature side Dewar component 1 to the cold mass 2 in the liquid helium temperature region. Moreover, titanium alloy is non-magnetic and will not interfere with the magnetic field of the superconducting magnet. It does not exhibit low-temperature brittleness in the liquid helium temperature region, maintaining good mechanical properties and ensuring the safety and stability of the suspension structure under extreme low-temperature conditions. Combined with the inclined arrangement of the inclined screw 32, the heat transfer path is extended, further reducing heat leakage. Thus, while ensuring load-bearing capacity and stable suspension, the number of tie rod components 3 is reduced, the overall structure is simplified, the space occupied by the vacuum interlayer is reduced, and the assembly difficulty and manufacturing cost are lowered.

[0043] Specifically, the Dewar assembly 1 serves as a room-temperature vacuum container, inside which a cold mass 2, located in the liquid helium temperature range, is suspended by multiple sets of tie rod assemblies 3. Tie rod seats 31 are fixed to the first upper end plate 12, the first lower end plate 13, the second upper end plate 21, and the second lower end plate 22, respectively. Inclined screws 32 pass obliquely through the tie rod seats 31 and are locked by adjusting nuts 33. Multiple sets of inclined screws 32 are evenly and symmetrically arranged in a circumferential direction and cross each other vertically, forming a spatial truss structure. The gravity of the cold mass 2 causes the inclined screws 32 to primarily bear tensile loads. The tensile force of a single inclined screw 32 can be decomposed into axial and radial components. The axial components of each inclined screw 32 are superimposed and balance the gravity of the cold mass 2, while the radial components cancel each other out in the circumferential direction, thus suspending the cold mass 2 within the liquid helium temperature range. The axial, radial, and circumferential directions are effectively constrained and the suspension is stable. The tie rod seat 31 is embedded in the groove 4, so that the shear stress is mainly borne by the mating surface of the groove 4. The inclined screw 32 mainly bears the tensile load. The adjusting nut 33 is used to apply the preload. The spherical washer 35 makes the preload evenly transmitted along the axis of the inclined screw 32, avoiding additional bending moment. At the same time, the inclined screw 32, made of titanium alloy, has low thermal conductivity. The inclined arrangement extends the heat transfer path. The heat insulation gasket 6 blocks the direct heat conduction between the tie rod seat 31 and the bottom surface of the groove 4, thereby significantly reducing the heat leakage from the room temperature side Dewar assembly 1 to the low temperature side cold mass 2. When the temperature change or vibration causes the preload to change, it can be compensated online by rotating the adjusting nut 33 to ensure the long-term stable suspension of the cold mass 2.

[0044] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A superconducting coil suspension structure, comprising a Dewar assembly (1), a cold mass (2) and multiple sets of tie rod assemblies (3), wherein the multiple sets of tie rod assemblies (3) are disposed in a vacuum interlayer between the Dewar assembly (1) and the cold mass (2); The Dewar assembly (1) includes a Dewar body (11) and a first upper end plate (12) and a first lower end plate (13) disposed above and below it. The cold mass (2) is located within the Dewar assembly (1) and includes a second upper end plate (21) and a second lower end plate (22). The tie rod assembly (3) includes a tie rod seat (31), a helical screw (32), and an adjusting nut (33). The tie rod seat (31) is respectively installed on the first upper end plate (12), the first lower end plate (13), the second upper end plate (21), and the second lower end plate (22). The helical screw (32) is inclined and its two ends pass through the corresponding tie rod seat (31) and are locked by the adjusting nut (33) to provide axial and radial constraints at the same time.

2. The superconducting coil suspension structure as described in claim 1, characterized in that, Multiple grooves (4) are provided on the first upper end plate (12), the first lower end plate (13), the second upper end plate (21), and the second lower end plate (22). The pull rod seat (31) is embedded in the groove (4) and can be detachably connected by fixing bolts (5).

3. The superconducting coil suspension structure as described in claim 1, characterized in that, Multiple sets of the tie rod assemblies (3) are evenly and symmetrically distributed in the circumferential direction of the Dewar assembly (1).

4. The superconducting coil suspension structure as described in claim 1, characterized in that, The tie rod assembly (3) located between the first upper end plate (12) and the second upper end plate (21) and the tie rod assembly (3) located between the first lower end plate (13) and the second lower end plate (22) are symmetrically arranged above and below the horizontal mid-plane of the cold mass (2) and are arranged in a cross pattern in a radial plane perpendicular to the circumferential direction, forming a space truss structure.

5. The superconducting coil suspension structure as described in claim 1, characterized in that, The tie rod seat (31) is provided with a mounting hole (34). The axis of the mounting hole (34) is inclined to the plane of the end plate, and the inclination angle is consistent with the inclination angle of the inclined screw (32).

6. The superconducting coil suspension structure as described in claim 1, characterized in that, The pull rod seat (31) includes a first seat body (311) and a second seat body (312). The first seat body (311) is respectively mounted on the first upper end plate (12) and the first lower end plate (13). The second seat body (312) is respectively mounted on the second upper end plate (21) and the second lower end plate (22). Along the radial direction of the Dewar assembly (1), the first seat body (311) is located radially outside the second seat body (312). The inclined screw (32) extends obliquely from the first seat body (311) to the second seat body (312).

7. The superconducting coil suspension structure as described in claim 1, characterized in that, The inclined screw (32) includes a smooth section (321) in the middle and external thread sections (322) at both ends. The diameter of the smooth section (321) is smaller than the outer diameter of the external thread section (322) and larger than the thread root diameter of the external thread section (322).

8. The superconducting coil suspension structure as described in claim 2, characterized in that, A heat insulation pad (6) is provided between the bottom surface of the pull rod seat (31) and the groove (4). The heat insulation pad (6) is used to block the heat directly conducted between the Dewar assembly (1) and the cold mass (2) through the pull rod seat (31).

9. The superconducting coil suspension structure as described in claim 1, characterized in that, Spherical washers (35) are provided between the two ends of the inclined screw (32) and the adjusting nut (33).

10. The superconducting coil suspension structure as described in claim 1, characterized in that, The inclined screw (32) is a titanium alloy screw.

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