Vibration reduction assembly and extremely low vibration reduction system for extremely low temperature refrigeration platform

Abstract

The utility model discloses a vibration reduction assembly and an extremely low vibration reduction system for an extremely low temperature refrigeration platform. The vibration reduction assembly comprises a main frame. The active suppression platform is arranged above the main frame, reads a signal in real time through a sensor in the active suppression platform and feeds back the signal to an internal control unit, and the control unit sends an instruction to reversely adjust the compression amount of an internal spring so as to realize active vibration reduction; the rotary valve vibration reduction mounting seat is used for respectively fixing the rotary valve motor and the phase modulation air reservoir through a supporting plate and a fixed clamping block and realizing vibration reduction through a vibration reduction element arranged in the rotary valve vibration reduction mounting seat; a second vibration reduction body is arranged in the corrugated pipe assembly so as to reduce vibration in the vertical direction and the radial direction. The active suppression platform is arranged to actively eliminate vibration, vibration or vibration transmission can be reduced, the corrugated pipe is arranged above the active suppression platform, vertical vibration of the cold head of the refrigerating machine can be reduced, the second vibration reduction bodies are arranged on the periphery of the corrugated pipe body, and radial vibration of the cold head of the refrigerating machine can be reduced through the second vibration reduction bodies.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical vibration, in particular to a vibration reduction component and an extremely low vibration reduction system for an extremely low temperature refrigeration platform. Background Art

[0002] In the field of superconducting quantum computing, extremely low temperature environments play a very important role. At the same time, superconducting quantum computing is very sensitive to environmental noise, and usually needs to be maintained in an extremely low temperature environment below 30mK to keep the quantum bit in a superconducting state. Dilution refrigeration technology is a reliable way to provide this extremely low temperature environment. At present, dilution refrigerators are almost all used in scientific research or commercial use. On the other hand, the high cost of preparing and maintaining liquid helium limits the feasibility of large-scale application of superconducting quantum computers. Liquid helium-free dilution refrigerators use an alternative cooling method that does not require liquid helium. It has a large sample space, long continuous operation time, and convenient operation and maintenance. It can reduce the cost of the cooling system and improve overall sustainability. It has rapidly become popular in the past decade and has become the mainstream of the market.

[0003] Existing liquid helium-free dilution refrigerators usually use separate PT pulse tube refrigerators. Although the vibration is smaller than that of integrated PT pulse tube refrigerators, the vibration problem is still a key problem that liquid helium-free dilution refrigerators need to solve. In addition, due to the environmental differences in the application scenarios of liquid helium-free dilution refrigerators, existing commercial liquid helium-free dilution refrigerators need further customized vibration reduction measures for specific use scenarios, which limits the versatility and scale of liquid helium-free dilution refrigerators. Taking the use scenarios of currently used liquid helium-free dilution refrigerators as an example, liquid helium-free dilution refrigerators have internal vibrations generated by the operation of PT pulse tube refrigerators (including pulse tube compressors, rotary valve motors of pulse tube refrigerators, helium gas pressure pulsations of pulse tube refrigerators, helium acoustic-vibration coupling vibrations, and helium hoses). In addition, external vibrations such as heavy-loaded vehicles and high-speed trains near the working area of ​​the liquid helium-free dilution refrigerator are transmitted to the liquid helium-free dilution refrigerator through the foundation. As a result, although there are some vibration reduction measures for liquid helium-free dilution refrigerators, the vibration often still cannot meet the requirements, and the vibration level usually needs to reach the submicron level. In order to expand the versatility and product stability of liquid helium-free dilution refrigerators, an extremely low vibration damping system that can cope with complex working conditions was developed.

[0004] At present, there are many vibration reduction improvements for liquid nitrogen dilution refrigerators, but a secondary frame is introduced in various improvement schemes, and even a remote rotary valve support platform is introduced in some improvement schemes, which causes the space occupation of the entire equipment. At the same time, most of the existing technical solutions only reduce vibration through bellows, but some harmful vibrations will still be transmitted to the lowest test sample area through various cold plates and supports, which cannot effectively reduce the harm caused by vibration. Utility Model Content

[0005] The utility model aims to solve the shortcomings in the prior art and proposes a vibration reduction component and an extremely low vibration reduction system for an extremely low temperature refrigeration platform.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solution: a vibration reduction component suitable for an extremely low temperature refrigeration platform of a superconducting quantum computer, comprising:

[0007] An upper fixing member fixed to a cold head of a pulse tube refrigerator in the extremely low temperature refrigeration platform;

[0008] A lower fixing member fixed to a normal temperature cold plate in the extremely low temperature refrigeration platform;

[0009] A first vibration damper is disposed between the upper fixing member and the lower fixing member;

[0010] A stop rod, one end of which is connected to the upper fixing member, and the other end of which is connected to the room temperature cold plate;

[0011] A second vibration damper is disposed on the room temperature cold plate;

[0012] A constraint adjustment rod, one end of which is connected to the second vibration damper and the other end of which is connected to the upper fixing member, wherein the constraint adjustment rod is used to adjust the initial height of the first vibration damper.

[0013] As a further description of the above technical solution: the upper fixing member and the lower fixing member are both adapted flanges, or

[0014] The upper fixing member and the lower fixing member are both adapted flanges, and the first vibration damping body is a bellows body.

[0015] As a further description of the above technical solution: the constraint adjustment rod and the stop rod are distributed circumferentially, or

[0016] The constraint adjustment rod and the stop rod are distributed circumferentially and the constraint adjustment rod and the stop rod appear alternately.

[0017] An extremely low vibration damping system for an extremely low temperature refrigeration platform, comprising:

[0018] Main frame;

[0019] An active suppression platform is arranged above the main frame. The active suppression platform reads signals in real time through its internal sensors and feeds back signals to the internal control unit. The control unit issues instructions to reversely adjust the internal spring compression to achieve active vibration reduction.

[0020] A rotary valve vibration reduction mounting seat is installed on one side of the main frame, and the rotary valve vibration reduction mounting seat fixes the phase-adjusting gas reservoir through a plurality of fixing clamps and realizes vibration reduction through the vibration reduction elements arranged inside the rotary valve vibration reduction mounting seat;

[0021] The vibration reduction component is installed above the active suppression platform through a room temperature cold plate of an extremely low temperature refrigeration platform. A second vibration reduction body is arranged in the vibration reduction component to reduce vibration in vertical and radial directions.

[0022] As a further description of the above technical solution: a pipeline is extended from one end of the phase-adjusting gas reservoir on the rotary valve vibration reduction mounting seat, and a pulse tube refrigerator cold head is connected through the pipeline;

[0023] The pulse tube refrigerator cold head is in contact with the extremely low temperature refrigeration platform 50K cold plate, the pulse tube refrigerator cold head is in contact with the extremely low temperature refrigeration platform 4K cold plate, and vibration-damping copper belts are provided between the pulse tube refrigerator cold head and the extremely low temperature refrigeration platform 50K cold plate, and between the pulse tube refrigerator cold head and the extremely low temperature refrigeration platform 4K cold plate;

[0024] A mixing chamber cold plate is connected below the pulse tube refrigerator cold head.

[0025] As a further description of the above technical solution: the vibration-damping copper belt includes an upper flange and a lower flange and a copper belt body arranged therebetween, and the upper flange and the lower flange are connected to the copper belt body by a press locking device.

[0026] As a further description of the above technical solution: the active suppression platform includes a rubber disc, a support base is arranged below the rubber disc, vibration-damping beams are symmetrically arranged on both sides below the support base, a connecting beam is arranged below the vibration-damping beam, and a control unit is arranged on one side of the main frame;

[0027] The vibration-damping beam is internally provided with a spring device, a sensor and an actuator. The sensor reads the vibration signal in real time and feeds it back to the control unit. The control unit issues a command to the actuator to reversely adjust the compression amount of the internal spring device to eliminate vibration.

[0028] As a further description of the above technical solution: the rotary valve vibration damping mounting seat includes a main support body, a vibration damping element is arranged on the upper surface of the main support body, a support plate is arranged on the vibration damping element, a fixed clamp block is arranged on the support plate, the phase-adjusting gas reservoir is fixed in the fixed clamp block, and the rotary valve motor is fixed on the upper surface of the support plate.

[0029] As a further description of the above technical solution: the vibration-damping elements and the fixed clamping blocks are made of rubber parts or polymer damping materials, and the fixed clamping blocks are arranged along a vertical array.

[0030] As a further description of the above technical solution: one end of the rotary valve motor is connected to a helium hose, and the outside of the helium hose is wrapped with sound insulation material.

[0031] As a further description of the above technical solution: the main frame includes a rectangular frame composed of a plurality of transverse rods and a longitudinal rod fixedly connected to the bottom of the rectangular frame, and a buffer pad is arranged at the bottom of each longitudinal rod.

[0032] As a further description of the above technical solution: the main support body includes a horizontal plate and a vertical plate, and the main support body is fixed to one side of the main frame.

[0033] The utility model has the following beneficial effects:

[0034] The utility model actively eliminates vibration by setting an active suppression platform to reduce vibration or vibration transmission. At the same time, the bellows body is set above the active suppression platform, which can further reduce vertical vibration, and a plurality of second vibration dampers are set around the bellows body. The second vibration dampers can reduce vertical vibration by a small amount, and mainly reduce the radial vibration of the cold head of the pulse tube refrigerator. The applicant found in the experiment that although the proportion of radial vibration is very small, radial vibration will aggravate the deterioration of vertical vibration. Therefore, the present application can effectively reduce vertical vibration and radial vibration by setting a second vibration damper in conjunction with the bellows. In addition, the rotary valve vibration damping mounting seat is set at the same time to effectively reduce various vibrations generated by the rotary valve motor, the phase-adjusting gas reservoir and the auxiliary components. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a front view of the extremely low vibration damping system proposed by the utility model;

[0036] Figure 2 A schematic diagram of the bellows assembly proposed in the utility model;

[0037] Figure 3 A schematic diagram of the rotary valve vibration reduction mounting seat proposed by the utility model;

[0038] Figure 4 A schematic diagram of the pulse tube refrigerator proposed in the utility model;

[0039] Figure 5 This is a schematic diagram of the main frame proposed by the utility model.

[0040] Legend:

[0041] 1. Buffer pad; 2. Main frame; 3. Rotary valve vibration reduction mount; 4. Pulse tube refrigerator; 5. Bellows assembly; 6. Cryogenic refrigeration platform normal temperature cold plate; 7. Active suppression platform; 8. Cryogenic refrigeration platform 50K cold plate; 9. Cryogenic refrigeration platform 4K cold plate; 10. Vibration reduction copper belt; 11. Mixing chamber cold plate;

[0042] 21. Transverse rod body; 22. Longitudinal rod body;

[0043] 31. Main support body; 32. Vibration reduction element; 33. Fixing bolt; 34. Support plate; 35. Fixing clamp; 311. Vertical plate; 312. Horizontal plate;

[0044] 41. Second stage of pulse tube refrigerator; 42. First stage of pulse tube refrigerator; 43. Cold head of pulse tube refrigerator; 44. Rotary valve motor; 45. Phase-adjusting gas reservoir; 46. Helium hose;

[0045] 51. Lower connecting flange; 52. Bellows body; 53. Upper connecting flange; 54. Stop rod; 55. Second vibration damping body; 56. Constraint adjustment rod; 57. Locking nut; 58. Fixing nut;

[0046] 71. Rubber disc; 72. Support base; 73. Vibration-absorbing longitudinal beam; 74. Connecting longitudinal beam; 75. Control unit. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0048] The embodiment of the present application solves the problem that harmful vibration is eliminated or filtered only by bellows in the prior art. However, in non-laboratory environments or when a new vibration source is added to the periphery of the laboratory in the later stage, harmful vibration cannot be effectively reduced only by the bellows body 52. ​​Some harmful vibration will still be transmitted to the test sample area at the bottom through the cold plates and support members at each level, affecting the normal test or work. The technical concept of the present application is to actively eliminate vibration by setting an active suppression platform 7 to reduce vibration or vibration transmission. At the same time, the bellows body 52 is arranged above the active suppression platform 7, which can further reduce vertical vibration, and a plurality of second vibration damping bodies 55 are arranged around the bellows body 52. ​​The second vibration damping body 55 can reduce vertical vibration by a small amount and reduce the radial vibration of the cold head of the pulse tube refrigerator. The applicant found in the experiment that although the proportion of radial vibration is very small, radial vibration will aggravate the deterioration of vertical vibration. Therefore, the present application can effectively reduce vertical vibration and radial vibration by setting the second vibration damping body 55 and the bellows body 52. In addition, the rotary valve vibration reduction mounting seat 3 is provided to effectively reduce various vibrations generated by the rotary valve motor 44, the phase-adjusting gas reservoir 45 and the auxiliary components.

[0049] Reference Figure 1-3, an embodiment provided by the utility model: an extremely low vibration damping system for an extremely low temperature refrigeration platform, which specifically includes a main frame 2, the main frame 2 serves as a bearing structure for other structural components, and the whole is a frame structure;

[0050] An active suppression platform 7 is installed above the main frame 2, and the bellows assembly 5 is also installed above the active suppression platform 7. The active suppression platform 7 reads the signal in real time through its internal sensor and feeds back to the internal control unit 75. The control unit 75 issues a command to reversely adjust the internal spring compression amount to achieve active vibration reduction. The multiple second vibration damping bodies 55 arranged in the bellows assembly 5 can reduce vertical vibration and radial vibration, thereby reducing the aggravation of radial vibration on vertical vibration.

[0051] A rotary valve vibration reduction mounting seat 3 is also provided on one side of the main frame 2, and a phase-adjusting gas reservoir 45 and a rotary valve motor 44 are fixed on the rotary valve vibration reduction mounting seat 3. Both of them will generate vibration during operation or running. The vibration reduction element 32 on the rotary valve vibration reduction mounting seat 3 can eliminate or weaken the vibration generated by the phase-adjusting gas reservoir 45 and the rotary valve motor 44 during use. At the same time, since the phase-adjusting gas reservoir 45 is connected to the pulse tube refrigerator 4 through a connecting pipe, and the pulse tube refrigerator 4 is connected to the bellows assembly 5, the vibration of the phase-adjusting gas reservoir 45 and the rotary valve motor 44 during operation is reduced, and the transmission of vibration to the bellows assembly 5 can also be reduced, thereby further reducing the vibration generation of the entire equipment, and effectively reducing the impact of vibration on the extremely low temperature refrigeration platform.

[0052] In summary, through the above technical scheme, the cooperation of multiple vibration reduction components can greatly reduce the vibration generation and transmission of the ultra-low temperature platform compared with a single bellows component 5 to weaken the vibration. It can be suitable for application scenarios with large environmental vibration, or it can deal with the impact of excessive vibration in the surrounding environment on the work of the liquid helium-free dilution refrigerator in the later stage. It can be used for most application scenarios and application conditions, and has stronger versatility.

[0053] refer to Figure 2A vibration reduction assembly, namely a bellows assembly 5, comprises a first vibration reduction body, namely a bellows body 52, an upper fixing member, namely an upper connecting flange 53, and a lower fixing member, namely a lower connecting flange 51, respectively connected to the upper and lower parts of the bellows body 52, wherein the upper connecting flange 53 is fixedly connected to the cold head of the pulse tube refrigerator 4, and the lower connecting flange 51 is fixedly connected to the normal temperature cold plate 6 of the extremely low temperature refrigeration platform, and a plurality of second vibration reduction bodies 55 are fixedly installed on the upper surface of the normal temperature cold plate 6 of the extremely low temperature refrigeration platform and are arranged around the bellows body 52, the second vibration reduction bodies 55 ensure that only the weight of the bellows body 52 and the weight acting on the bellows body 52 are basically eliminated in the vertical direction, and have appropriate stiffness and damping in the radial direction to attenuate or dissipate radial vibration, which can reduce the deterioration or aggravation of vertical and longitudinal vibrations when radial vibration occurs. A constraint adjustment rod 56 is provided on each second vibration damper 55. The constraint adjustment rod 56 passes through the mounting hole of the upper connecting flange 53. The constraint adjustment rod 56 adjusts the height of the bellows body 52 to keep the bellows body 52 in a free length state and fixes the upper and lower surfaces of the upper connecting flange 53 simultaneously through the fixing nut 58 and the locking nut 57. The locking nut 57 is used in pairs to reduce the risk of loosening. A plurality of stop rods 54 are fixed on the room temperature cold plate 6 of the extremely low temperature refrigeration platform. The stop rod 54 passes through the mounting hole on the upper connecting flange 53. When the bellows body 52 is in a free length state, it is fixed to the upper end face of the upper connecting flange 53 by the fixing nut 58, so that it can vibrate freely downward, while the upward vibration is blocked by the stop rod 54. The stop rod 54 makes a cutoff mark line at a certain distance from the end face of the upper connecting flange 53, which can be used to judge whether the bellows body 52 fails and needs to be replaced or to record certain abnormal vibrations. Preferably, the second vibration damping body 55 , the constraint adjustment rod 56 and the stop rod 54 are uniformly and alternately distributed in the circumferential direction of the bellows body 52 , such as three times, four times, five times and six times.

[0054] refer to Figure 3 , the above-mentioned rotary valve vibration reduction mounting seat 3 is described in detail:

[0055] It includes a main support body 31, a vibration-damping element 32, fixing bolts 33, a support plate 34, and a fixing clamp 35. The main support body 31 includes a transverse plate 311 and a vertical plate 312. The transverse plate 311 and the vertical plate 312 can be integrated or fixedly connected to form an L-shape or a T-shape or an equivalent shape. The main support body 31 is fixed to the transverse rod 21 or the longitudinal rod 22 of the main frame 2, preferably connected to the longitudinal rod 22, so that the entire device is more compact and can reduce the occupation of external space. The vibration-damping element 32 is preferably a rubber part or a polymer damping material, placed between the support plate 34 and the transverse plate 312, and fixed by bolts. The vibration-damping element 32 is symmetrically arranged at the four corners. A pair of fixing clamps 35 are provided on the support plate 34, wherein the fixing clamps 35 are also damping materials, which play the role of fixing the phase-adjusting gas reservoir 45 and reducing the vibration caused by the pulsation change of helium pressure. The fixing clamps 35 are arranged in a row in the vertical direction, or arranged side by side on the support plate 34. At the same time, the rotary valve motor 44 is also arranged on the upper surface of the support plate 34, and one end of the rotary valve motor 44 is connected to the helium hose 46 of the pulse tube refrigerator 4. The sound insulation material is wrapped on the outside of the helium hose 46 to reduce the sound generated by the pressure pulsation of the instrument when the rotary valve motor 44 switches between high and low pressure helium, thereby reducing the problem of acoustic-vibration coupling aggravating vibration, which can effectively reduce the acoustic-vibration coupling vibration and further reduce harmful vibration.

[0056] refer to Figure 1 , the above-mentioned active suppression platform 7 is described in detail:

[0057] The active suppression platform 7 includes a rubber disc 71, a support base 72, a vibration-damping longitudinal beam 73, a connecting longitudinal beam 74 and a control unit 75. The rubber disc 71 is clamped between the room temperature cold plate 6 of the extremely low temperature refrigeration platform and the support base 72 and fixedly connected. The support base 72 is placed flat on a pair of vibration-damping longitudinal beams 73 and fixed by bolts. The vibration-damping longitudinal beam 73 is placed flat on the connecting crossbeam of the main frame 2 and fixed. The control unit 75 is fixed on the connecting longitudinal beam 74 on one side of the main support frame. A spring device, a sensor and an actuator are arranged inside the vibration-damping longitudinal beam 73. The sensor reads the vibration signal in real time and feeds it back to the control unit 75. The control unit 75 sends a command to the actuator to reversely adjust the compression amount of the internal spring to eliminate the vibration, thereby realizing active vibration reduction control. Preferably, multiple groups of internal springs are used to improve the uniformity of the sensor readings. Preferably, the sensor can be a force sensor or a displacement sensor, corresponding to the reverse force control or displacement control of the actuator.

[0058] refer to Figure 1 and Figure 4 , the connection between the components on the rotary valve vibration damping mounting seat 3 and the bellows body 52 is described in detail:

[0059] A pipeline is extended from one end of the phase-adjusting gas reservoir 45 on the rotary valve vibration-damping mounting seat 3, and is connected to a pulse tube refrigerator cold head 43 through the pipeline. The tube refrigerator cold head 43 includes a pulse tube refrigerator stage 42 and a pulse tube refrigerator stage 41;

[0060] The first stage 42 of the pulse tube refrigerator is in contact with the 50K cold plate 8 of the extremely low temperature refrigeration platform, the second stage 41 of the pulse tube refrigerator is in contact with the 4K cold plate 9 of the extremely low temperature refrigeration platform, and a vibration-damping copper belt 10 is provided between the 4K cold plate 9 of the extremely low temperature refrigeration platform and the second stage 41 of the pulse tube refrigerator;

[0061] A mixing chamber cold plate 11 is connected below the second stage 41 of the pulse tube refrigerator through a bracket structure, and the mixing chamber cold plate 11 can perform low-temperature cooling on the experimental samples.

[0062] The above-mentioned vibration-damping copper belt 10 is fixedly installed between the first stage 42 of the pulse tube refrigerator and the 50K cold plate 8 of the ultra-low temperature refrigeration platform, the second stage 41 of the pulse tube refrigerator and the 4K cold plate 9 of the ultra-low temperature refrigeration platform, and specifically includes an upper flange and a lower flange and a copper belt body arranged therebetween. The upper flange and the lower flange are connected to the copper belt body by a press-locking device. The working principle of the press-locking device is described. The metal spring sheet inside the press-locking device has a certain elasticity. These spring sheets bend under force and have the ability to clamp the copper wire. A handle is provided inside to control the pressure of the spring sheet. When the copper wire is inserted into place, the spring sheet will apply a certain force to the copper wire, thereby ensuring that the copper wire is pressed by the press-locking device. The copper wire connected at the end can be processed by a wire crimping pliers to increase friction, further ensuring the effect of pressing and locking. Specifically, when in use, the handle is opened to 90°, and the metal spring sheet is not subjected to force and is in a naturally open state. The copper wire at the end of the vibration-damping copper braid is inserted into the guide groove / guide hole of the press-locking device, so that the copper wire is inserted into the metal spring sheet. The handle is closed and returned to 0°, which generates pressure on the metal spring sheet and acts on the copper wire, so that the copper wire is in a compressed state, thereby realizing a quick connection between the copper belt body and the upper and lower flanges, which is easier to replace.

[0063] At the same time, the press-locking device is also applied to the elastic part installation interface of the mixing chamber cold plate 11. The installation interface is used to install elastic elements with good thermal conductivity and vibration reduction, such as springs of the same material or other similar elements that can be equivalently replaced, to prevent further vibration reduction when the vibration still does not meet the requirements under extreme abnormal conditions. The elastic part installation interface of the mixing chamber cold plate 11 can directly reserve installation holes in the mixing chamber cold plate 11 or pre-install secondary adapter blocks on the mixing chamber cold plate 11. Adapter blocks are preferred because test samples may be frequently replaced during scientific research, and the elastic parts of the mixing chamber cold plate 11 may also be frequently disassembled and assembled, thereby reducing the situation in which the installation holes on the mixing chamber cold plate 11 are frequently used and the life of the mixing chamber cold plate 11 is reduced.

[0064] Please refer to Figure 5 , the main frame 2 is described in detail. The main frame 2 includes a rectangular frame composed of a plurality of transverse rods 21 and a longitudinal rod 22 fixedly connected to the bottom of the rectangular frame. The structure of the frame is a hollow structure so that a plurality of cold plates can be normally installed inside the frame, and a buffer pad 1 is provided at the bottom of each longitudinal rod 22 to reduce vibration transmitted from the ground or the installation position to the main frame 2.

[0065] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A vibration reduction component, suitable for a very low temperature refrigeration platform of a superconducting quantum computer, characterized in that: include: An upper fixing member fixed to a cold head of a pulse tube refrigerator in the extremely low temperature refrigeration platform; A lower fixing member fixed to a normal temperature cold plate in the extremely low temperature refrigeration platform; A first vibration damper is disposed between the upper fixing member and the lower fixing member; A stop rod, one end of which is connected to the upper fixing member, and the other end of which is connected to the room temperature cold plate; A second vibration damper is disposed on the room temperature cold plate; A constraint adjustment rod, one end of which is connected to the second vibration damper and the other end of which is connected to the upper fixing member, wherein the constraint adjustment rod is used to adjust the initial height of the first vibration damper.

2. The vibration reduction assembly according to claim 1, characterized in that: The upper fixing member and the lower fixing member are both adapted flanges, or The upper fixing member and the lower fixing member are both adapted flanges, and the first vibration damping body is a bellows body.

3. The vibration reduction assembly according to claim 1 or 2, characterized in that: The constraint adjustment rod and the stop rod are distributed circumferentially, or The constraint adjustment rod and the stop rod are distributed circumferentially and the constraint adjustment rod and the stop rod appear alternately.

4. An extremely low vibration damping system for an extremely low temperature refrigeration platform, characterized in that: include: Main frame; An active suppression platform is arranged above the main frame. The active suppression platform reads signals in real time through its internal sensors and feeds back signals to the internal control unit. The control unit issues instructions to reversely adjust the internal spring compression to achieve active vibration reduction. A rotary valve vibration reduction mounting seat is installed on one side of the main frame, and the rotary valve vibration reduction mounting seat fixes the phase-adjusting gas reservoir through a plurality of fixing clamps and realizes vibration reduction through the vibration reduction elements arranged inside the rotary valve vibration reduction mounting seat; The vibration reduction component is installed above the active suppression platform through a room temperature cold plate of an extremely low temperature refrigeration platform. A second vibration reduction body is arranged in the vibration reduction component to reduce vibration in vertical and radial directions.

5. The ultra-low vibration damping system for an ultra-low temperature refrigeration platform according to claim 4, characterized in that: A pipeline is extended from one end of the phase-adjusting gas reservoir on the rotary valve vibration-damping mounting seat, and a pulse tube refrigerator cold head is connected through the pipeline; The pulse tube refrigerator cold head is in contact with the extremely low temperature refrigeration platform 50K cold plate, the pulse tube refrigerator cold head is in contact with the extremely low temperature refrigeration platform 4K cold plate, and vibration-damping copper belts are provided between the pulse tube refrigerator cold head and the extremely low temperature refrigeration platform 50K cold plate, and between the pulse tube refrigerator cold head and the extremely low temperature refrigeration platform 4K cold plate; A mixing chamber cold plate is connected below the pulse tube refrigerator cold head.

6. The ultra-low vibration damping system for an ultra-low temperature refrigeration platform according to claim 5, characterized in that: The vibration-damping copper belt comprises an upper flange, a lower flange and a copper belt body arranged therebetween. The upper flange and the lower flange are connected to the copper belt body via a pressing and locking device.

7. The ultra-low vibration damping system for an ultra-low temperature refrigeration platform according to claim 4, characterized in that: The active suppression platform comprises a rubber disc, a support base is arranged below the rubber disc, vibration-damping beams are symmetrically arranged on both sides below the support base, a connecting beam is arranged below the vibration-damping beam, and a control unit is arranged on one side of the main frame; The vibration-damping beam is internally provided with a spring device, a sensor and an actuator. The sensor reads the vibration signal in real time and feeds it back to the control unit. The control unit issues a command to the actuator to reversely adjust the compression amount of the internal spring device to eliminate vibration.

8. The ultra-low vibration damping system for an ultra-low temperature refrigeration platform according to claim 5, characterized in that: The rotary valve vibration damping mounting seat comprises a main support body, a support plate is arranged on the vibration damping element, a fixed clamp block is arranged on the support plate, a phase-adjusting gas reservoir is fixed in the fixed clamp block, and a rotary valve motor is fixed on the upper surface of the support plate.

9. The ultra-low vibration damping system for an ultra-low temperature refrigeration platform according to claim 8, characterized in that: The vibration-damping elements and the fixed clamping blocks are made of rubber pieces or polymer damping materials, and the fixed clamping blocks are arranged along a vertical array.

10. The ultra-low vibration damping system for an ultra-low temperature refrigeration platform according to claim 8, characterized in that: One end of the rotary valve motor is connected to a helium hose, and the outside of the helium hose is wrapped with sound insulation material.

11. The ultra-low vibration damping system for an ultra-low temperature refrigeration platform according to claim 4, characterized in that: The main frame comprises a rectangular frame formed by a plurality of transverse rods and a longitudinal rod fixedly connected to the bottom of the rectangular frame, and a buffer pad is arranged at the bottom of each longitudinal rod.

12. The ultra-low vibration damping system for an ultra-low temperature refrigeration platform according to claim 8, characterized in that: The main support body comprises a horizontal plate and a vertical plate, and the main support body is fixed to one side of the main frame.

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