Low-temperature vacuum pump with controllable air exhaust rate and air exhaust capacity

Abstract

The invention relates to the technical field of vacuum pumps, in particular to a low-temperature vacuum pump with controllable air exhaust rate and air exhaust capacity, which comprises a pump shell, a vacuum assembly, a refrigeration assembly and an adjusting assembly. The vacuum assembly and the refrigeration assembly are arranged in the pump shell, gas can be adsorbed or condensed at low temperature, the needed vacuum environment can be rapidly achieved, the stable vacuum state can be kept, the vacuum pump is particularly suitable for the semiconductor machining process, the pure vacuum environment is provided, other impurities are not introduced, and the machining precision is guaranteed; meanwhile, by arranging the adjusting assembly, opening or closing of the gas adsorption channel can be controlled, the gas extraction rate and the gas extraction capacity can be adjusted and controlled, follow-up maintenance is facilitated, when a fault occurs, only the fault pump needs to be maintained, the multiple low-temperature vacuum pumps in the pump set do not need to be shut down for maintenance, operation is more convenient, and the working efficiency is improved. The working efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of vacuum pump technology, and specifically to a cryogenic vacuum pump with controllable pumping speed and pumping capacity. Background Technology

[0002] In semiconductor manufacturing, most processes require a vacuum environment. Cryogenic vacuum pumps are widely used due to their advantages such as large gas capacity and fast pumping speed. Currently, larger semiconductor manufacturing equipment requires higher vacuum levels and a stable vacuum environment. Therefore, multiple vacuum devices, i.e., cryogenic vacuum pump arrays, are often installed on a single processing unit to ensure the required vacuum environment is achieved. However, in actual use, the vacuum effect is often unsatisfactory, and the pumping speed of most cryogenic vacuum pumps is inconvenient to adjust and control, leading to operational difficulties. Furthermore, it is inevitable that one of the cryogenic vacuum pumps in the array will fail, making it difficult to maintain a constant vacuum in the vacuum chamber. This necessitates a complete shutdown to replace or repair the faulty pump, significantly impacting processing efficiency. Therefore, based on these problems, existing technologies require further improvement. Summary of the Invention

[0003] The purpose of this invention is to provide a cryogenic vacuum pump with controllable pumping speed and pumping capacity, so as to solve the existing technical problems in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a cryogenic vacuum pump with controllable pumping speed and pumping capacity, comprising a pump housing, a vacuum component, a cooling component, and an adjustment component. The vacuum component includes a radiation screen and a cooling umbrella structure, both disposed within the pump housing. The cooling umbrella structure is provided with adsorption material for adsorbing or condensing gas molecules at low temperatures to form a vacuum environment. The cooling component includes a multi-stage cylinder with its free end disposed inside the vacuum component. Cooling gas flows within the cooling component to provide a cryogenic environment for the vacuum component. The adjustment component is disposed within the pump housing with its end located at the gas inlet, and is used to adjust the pumping speed and pumping capacity.

[0005] Based on the above technical solution, the radiation screen is fixedly installed on the inner side wall of the pump housing and its shape is adapted to it. A gap is provided between the outer side wall of the radiation screen and the inner side wall of the pump housing, and a through hole is provided at the bottom end of the radiation screen.

[0006] Based on the above technical solution, the cooling umbrella structure includes a first baffle, a second baffle, and a first cooling umbrella. The first baffle is fixedly installed at the top of the inner wall of the radiation screen, the second baffle is fixedly installed inside the first baffle, and the first cooling umbrella is installed inside the radiation screen and below the first baffle and the second baffle.

[0007] Based on the above technical solution, the first baffle includes a baffle end plate and a baffle blade. The baffle end plate is configured as an annular end plate, and multiple sets of elongated holes are provided on the baffle end plate. One end of the baffle blade is located at the bottom end of the elongated holes.

[0008] Based on the above technical solution, the second baffle includes a fixing plate and a circular baffle. The fixing plate is located at the center of the axis of the radiation screen, and the circular baffle is located on the outside of the fixing plate. There are multiple circular baffles, and their diameters increase sequentially from the inside to the outside.

[0009] Based on the above technical solution, the first cooling umbrella includes multiple cooling umbrella panels that are evenly arranged from top to bottom. Each cooling umbrella panel includes an end plate and a side plate. The side plate is fixedly arranged on the side wall of the end plate and is inclined to the end plate.

[0010] Based on the above technical solution, the refrigeration component includes a primary cylinder and a secondary cylinder. A primary piston is provided in the primary cylinder, and a secondary piston is provided in the secondary cylinder. A drive component is provided at the head end of the primary piston, and the end end is connected to the head end of the secondary piston. The end of the secondary cylinder is located inside the cooling umbrella structure.

[0011] Based on the above technical solution, the drive assembly includes a drive motor, an eccentric shaft, an eccentric wheel, and a drive frame. The eccentric shaft is driven to rotate by the drive motor. The eccentric wheel is fixedly sleeved on the eccentric shaft and is disposed in the drive frame. The drive frame is connected to the first end of the first-stage piston.

[0012] Based on the above technical solution, the regulating component includes a first valve, a first valve stem, and a first actuator. The first valve is disposed at the open end of the pump housing and is structurally compatible. The first valve stem is fixedly disposed on the first valve. The first actuator drives the first valve to reciprocate through the first valve stem.

[0013] Based on the above technical solution, the regulating component further includes a second valve, a second valve stem, and a second actuator. The second valve is located at the outlet of the gas channel. The second valve stem is fixedly mounted on the second valve. The second actuator drives the second valve to reciprocate through the second valve stem. The second actuator is fixedly mounted on the outside of the first valve. A displacement hydraulic rod is provided between the first valve and the second valve.

[0014] The beneficial effects of the technical solution provided by this invention are as follows:

[0015] This invention incorporates a vacuum component and a cooling component within the pump housing, enabling the adsorption or condensation of gases at low temperatures. This rapidly achieves the required vacuum environment and maintains a stable vacuum state, making it particularly suitable for semiconductor processing. It provides a pure vacuum environment, preventing the introduction of other impurities and ensuring processing precision. Furthermore, the inclusion of an adjustment component allows for the control of the opening and closing of the adsorption gas channel, enabling the adjustment and control of the pumping rate and capacity. This facilitates subsequent maintenance; in case of a malfunction, only the faulty pump needs maintenance, eliminating the need to shut down multiple cryogenic vacuum pumps in the pump group for repair. This makes operation more convenient and improves work efficiency. Specifically, the radiation screen of the vacuum component can reflect heat energy from the environment, reducing heat radiation to the internal cooling umbrella structure and minimizing fluctuations in the vacuum environment caused by thermal radiation. By setting up the cooling umbrella structure and its adsorption material, gas molecules in the environment can be condensed or adsorbed and solidified on the cooling umbrella structure at low temperatures, achieving the required vacuum environment. By setting up multi-stage cylinders in the refrigeration component and the refrigeration gas flowing inside, the compressed helium gas inside the cylinder expands and does work to cool down, providing a low-temperature state for the radiation screen and cooling umbrella structure, and completing the rapid adsorption and solidification of gas molecules. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 This is a schematic diagram of the internal structure of the vacuum component in this invention;

[0018] Figure 3 This is a schematic diagram of the structure of the first baffle in this invention;

[0019] Figure 4 This is a schematic diagram of the structure of the second baffle in this invention;

[0020] Figure 5 This is a schematic diagram of the structure of the first cooling umbrella in this invention;

[0021] Figure 6 This is a schematic diagram of the structure of the refrigeration component in this invention;

[0022] Figure 7 This is a schematic diagram of the internal structure of the cooling component and the driving component in this invention;

[0023] Figure 8 This is a schematic diagram of the adjustment component in Embodiment 2 of the present invention;

[0024] Figure 9 This is a schematic diagram of the adjustment component in Embodiment 3 of the present invention; Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0026] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] In the description of this invention, it should be understood that the terms "left", "right", "front", "rear", "top", "bottom", 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 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 limitations on this invention.

[0028] Example 1

[0029] like Figures 1 to 7 As shown, a cryogenic vacuum pump with controllable pumping speed and pumping capacity includes a pump housing 1, a vacuum component 2, a cooling component 3, and an adjustment component. The vacuum component 2 includes a radiation screen 21 and a cooling umbrella structure, both of which are disposed within the pump housing 1. The cooling umbrella structure is provided with adsorption material for adsorbing or condensing gas molecules at low temperatures to form a vacuum environment. The cooling component 3 includes a multi-stage cylinder with its free end disposed inside the vacuum component 2. Cooling gas flows within the cooling component 3 to provide a cryogenic environment for the vacuum component 2. The adjustment component is disposed within the pump housing 1 with its end located at the gas inlet and is used to adjust the pumping speed and pumping capacity.

[0030] In this invention, by incorporating a vacuum component 2 and a cooling component 3 within the pump housing 1, the adsorption or condensation of gases can be achieved at low temperatures, rapidly creating the required vacuum environment and maintaining a stable vacuum state. This is particularly suitable for semiconductor processing, providing a pure vacuum environment with a vacuum level reaching 10. -9Pa, without introducing other impurities, ensures processing precision; simultaneously, by setting an adjustment component, the opening or closing of the adsorption gas channel can be controlled, realizing the adjustment and control of the pumping rate and pumping capacity, facilitating subsequent maintenance. In case of failure, only the faulty pump needs maintenance, without having to shut down multiple cryogenic vacuum pumps in the pump group for repair, making operation more convenient and improving work efficiency. Specifically, the pump housing end is provided with a flange for installation and disassembly with the process chamber; through the radiation screen 21 of the vacuum component 2, heat energy in the environment can be reflected, reducing heat radiation to the internal cold umbrella structure and reducing the fluctuations that heat radiation may cause to the vacuum environment; by setting the cold umbrella structure and the adsorption material on it, gas molecules in the environment can be condensed or adsorbed and solidified on the cold umbrella structure at low temperature to achieve the required vacuum environment; by setting the multi-stage cylinder in the refrigeration component 3 and the refrigeration gas flowing inside it, the compressed helium gas inside the cylinder expands and does work to cool, providing a low temperature state for the radiation screen and cold umbrella structure, completing the rapid adsorption and solidification of gas molecules. Preferably, the adsorption material is activated carbon, and the refrigeration gas is helium.

[0031] Based on the above technical solution, the radiation screen 21 is fixedly installed on the inner side wall of the pump housing 1 and its shape is adapted to the inner side wall. A gap is provided between the outer side wall of the radiation screen 21 and the inner side wall of the pump housing 1, and a through hole is provided at the bottom end of the radiation screen 21.

[0032] In a preferred embodiment, a gap is provided between the pump housing 1 and the radiation screen 21 to form an auxiliary gas channel. In this way, the gas enters the interior through the cooling umbrella structure during the flow process. The gas can directly enter the cooling umbrella structure, and at the same time, some gas can enter the cooling umbrella structure through the auxiliary gas channel and through holes. This allows the gas molecules to be quickly and effectively adsorbed and solidified.

[0033] Based on the above technical solution, the cooling umbrella structure includes a first baffle 22, a second baffle 23 and a first cooling umbrella 24. The first baffle 22 is fixedly disposed at the top of the inner side wall of the radiation screen 21, the second baffle 23 is fixedly disposed inside the first baffle 22, and the first cooling umbrella 24 is disposed inside the radiation screen 21 and below the first baffle 22 and the second baffle 23.

[0034] The cooling umbrella structure includes a first baffle 22 and a second baffle 23, along with adsorption materials, forming a first adsorption structure at low temperatures. This provides adsorption and condensation sites for gas molecules, achieving the high vacuum required in the processing environment. It also effectively reduces the direct impact of gas on the internal first cooling umbrella 24, providing protection and extending its service life. Furthermore, by incorporating the first cooling umbrella 24 within the radiation screen 21, a second adsorption structure is formed at low temperatures, providing adsorption and condensation sites for most gas molecules, rapidly achieving a high vacuum environment.

[0035] Based on the above technical solution, the first baffle 22 includes a baffle end plate 221 and a baffle blade 222. The baffle end plate 221 is configured as an annular end plate, and multiple sets of elongated holes 223 are provided on the baffle end plate 221. One end of the baffle blade 222 is located at the bottom end of the elongated hole 223.

[0036] Based on the above technical solution, the baffle blades 222 and the baffle end plate 221 are inclined together. By providing the first baffle 22 in the cooling umbrella structure, both the baffle end plate 221 and the baffle blades 222 are provided with adsorption material to adsorb and condense the gas, quickly achieving a vacuum environment. Simultaneously, the baffle blades 222 are provided with multiple sets of elongated holes 223, which are inclined, increasing the effective adsorption area and radiating some heat, reducing the impact of thermal radiation on the vacuum environment and ensuring good vacuum stability. The first baffle 22 is provided with multiple sets of elongated holes 223, each set having multiple elongated holes 223, providing a flow channel for the gas to enter the cooling umbrella structure for adsorption and condensation, achieving a vacuum state. In a preferred embodiment, the baffle blades 222 are directly punched downwards from the baffle end plate 221, meaning only one side of the baffle blade 222 is connected to the baffle end plate 221, while the other three sides are punched away from the baffle end plate 221, forming an inclined state with the baffle end plate 221.

[0037] Based on the above technical solution, each group of elongated holes 223 is provided with multiple holes along the diameter direction of the baffle end plate 221. The elongated holes 223 are arc-shaped and their lengths increase sequentially. In a preferred embodiment, the elongated holes 223 are arc-shaped and the lengths of the multiple elongated holes 223 in each group increase sequentially, which can increase the effective adsorption area of ​​the gas, increase the gas flow rate, quickly and efficiently achieve the required vacuum environment, and maintain the stability of the vacuum state.

[0038] Based on the above technical solution, the second baffle 23 includes a fixing plate 231 and an annular baffle 232. The fixing plate 231 is disposed at the center of the axis of the radiation screen 21, and the annular baffle 232 is disposed on the outside of the fixing plate 231. Multiple annular baffles 232 are provided, and their diameters increase sequentially from the inside to the outside.

[0039] By incorporating a second baffle 23 in the cooling umbrella structure, which consists of multiple annular baffles 232 with progressively increasing diameters, the gas adsorption area is large, ensuring rapid achievement of a vacuum state and a good vacuum effect. More preferably, the annular baffles 232 are all inclined, which can increase the effective gas adsorption area. At the same time, the inclined annular baffles 232 can also radiate some heat, maintaining the stability of the vacuum environment.

[0040] Based on the above technical solution, the first cooling umbrella 24 includes a plurality of cooling umbrella pieces that are evenly arranged from top to bottom. Each cooling umbrella piece includes an end plate 241 and a side plate 242. The side plate 242 is fixedly arranged on the side wall of the end plate 241 and is inclined to the end plate 241.

[0041] By incorporating a first cooling umbrella 24 within the cooling umbrella structure, comprising multiple cooling umbrella plates arranged from top to bottom, and using adsorption material on them, more adsorption and condensation sites are provided for gas molecules, enabling rapid achievement of the desired vacuum state. More preferably, the angle between the side plate 242 and the end plate 241 in the cooling umbrella plates is obtuse, allowing the side plate 242 to reflect some thermal radiation, reducing the adverse effects of heat on temperature and vacuum level, and minimizing fluctuations in vacuum level. Specifically, as... Figure 5 As shown, all the cooling umbrellas are fixedly mounted on the mounting bracket 25, which is fixedly connected to the refrigeration assembly 3. Except for the topmost cooling umbrella, the other cooling umbrellas have notches on their sides, mainly to accommodate the installation of the cylinder part in the refrigeration assembly. The other cooling umbrellas have openings at their centers, forming radial through grooves. The mounting bracket 25 is placed in the through grooves to facilitate the fixing of the cooling umbrellas and also to promote the rapid flow of gas and the adsorption and condensation of its contained molecules.

[0042] In a more preferred embodiment, multiple cooling umbrellas are fixedly mounted on the mounting frame 25. Multiple through holes 243 are formed on the end face of one of the top cooling umbrellas, and the mounting frame 25 also has multiple through holes. The mounting frame 25 facilitates the fixing and disassembly of the multiple cooling umbrellas. Combined with the through holes, it facilitates gas flow and promotes more comprehensive adsorption of molecules in the environment, thus meeting the requirements for a high vacuum environment.

[0043] Based on the above technical solution, the refrigeration component 3 includes a primary cylinder 31 and a secondary cylinder 32. A primary piston 33 is provided in the primary cylinder 31, and a secondary piston 34 is provided in the secondary cylinder 32. A drive component 35 is provided at the head end of the primary piston 33, and the end end is connected to the head end of the secondary piston 34. The end end of the secondary cylinder 32 is located inside the cooling umbrella structure.

[0044] By incorporating a primary cylinder 31 and a secondary cylinder 32 within the refrigeration assembly 3, a low-temperature environment is provided for the radiation screen 21 and the cooling umbrella structure, facilitating gas adsorption under the action of the adsorption material and achieving a vacuum environment. Specifically, the primary cylinder 32 is in thermal contact with the radiation screen 21, and the secondary cylinder 31 is in thermal contact with the cooling umbrella structure. The primary piston 33, driven by the drive assembly 35, causes the secondary piston 34 to reciprocate, expanding the refrigeration gas and performing work, thus achieving refrigeration and providing the required adsorption temperature for the radiation screen 21 and the cooling umbrella structure. This enables the adsorption and condensation of gas molecules in the environment, achieving a vacuum. Preferably, the secondary cylinder 32 is fixedly mounted within the cooling umbrella structure via a mounting bracket 25, which is fixedly connected to the interior of the cooling umbrella blades. The interior of the cooling umbrella blades is provided with a through groove adapted to the mounting bracket 25.

[0045] In a more preferred embodiment, the first-stage piston 33 is provided with multiple layers of copper mesh 331, and the second-stage piston 34 is filled with lead particles. Both ends of the first-stage piston 33 and the second-stage piston 34 are provided with inlet and outlet ports for the refrigerant gas. By providing inlet and outlet ports, the refrigerant gas flows within the first-stage piston 33 and the second-stage piston 34. Particularly when flowing through the interior of the first-stage piston 33, this preferred embodiment provides multiple layers of dense copper mesh 331, which has a heat storage and cooling effect, enabling heat exchange of the passing helium gas, reducing temperature and vacuum drift and fluctuations, and ensuring the stability of the processing environment. The lead particles filled inside the second-stage piston 34 also have a filtering function, removing impurities from the helium gas during its flow, improving the efficiency of helium work, and enhancing the cleanliness of the vacuum environment.

[0046] Based on the above technical solution, the drive assembly 35 includes a drive motor 351, an eccentric shaft 352, an eccentric wheel 353, and a drive frame 354. The eccentric shaft 352 is driven to rotate by the drive motor 351. The eccentric wheel 353 is fixedly sleeved on the eccentric shaft 352. The eccentric wheel 353 is disposed in the drive frame 354. The drive frame 354 is connected to the first end of the first stage piston 33.

[0047] Specifically, the drive frame 354 is arranged in a U-shape; the drive motor 351 drives the eccentric shaft 352 and the eccentric wheel 353 on it to move, which in turn drives the drive frame 354 to reciprocate, thereby driving the first-stage piston 33 and the second-stage piston 34 to reciprocate, doing work on the helium gas. The compressed helium gas absorbs heat during the compression and expansion process, reducing the temperature of the first-stage cylinder 31 and the second-stage cylinder 32, achieving a low-temperature state in the radiation screen 21 and the cold umbrella structure, thereby enabling the cold umbrella structure to adsorb molecules in the gas at a low temperature.

[0048] In a more preferred embodiment, the refrigerant gas is controlled for inlet and outlet by a gas control device 4. The gas control device 4 includes a base 41, an inlet valve, an outlet valve, and a valve switch 42. The base 41 is fixedly connected to a cylinder base 10, which is fixedly located at the end of a first-stage cylinder 31. The inlet valve and outlet valve are respectively located within the base 41. The valve switch 42 is respectively located for the inlet valve and outlet valve, controlling their opening and closing. The valve switch 42 includes a timing valve arm 421, a ejector pin 422, and an eccentric bearing 423. One side of the timing valve arm 421 is connected to the inlet valve or outlet valve via the ejector pin 422, and the other side abuts against the eccentric bearing 423, which is sleeved on an eccentric shaft 352.

[0049] It is understood that two eccentric bearings 423 are sleeved on the eccentric shaft 352 corresponding to the intake valve and the exhaust valve. Correspondingly, two valve swing arms 421 are provided, which are respectively set on one side of the intake valve or the exhaust valve. During the process of the drive motor 351 driving the eccentric shaft 352 to rotate, the different eccentric bearings 423 on it drive different valves during the movement to realize the process of air intake or air exhaust.

[0050] In use, the cryogenic vacuum pump of this invention is mounted on the semiconductor processing chamber, referred to as the process chamber. Depending on actual needs, multiple cryogenic pumps can be installed on the process chamber to ensure the vacuum level within it. Helium is pressurized by a compressor and delivered to the cryogenic vacuum pump. Helium inlet and outlet pipes are correspondingly installed on the inlet and outlet valves to achieve helium intake and exhaust. Then, driven by the drive assembly, the first and second stage pistons reciprocate, causing helium to expand, absorb heat, and cool, achieving a cryogenic state for the first and second stage cylinders, the radiation screen, and the cooling umbrella structure. The helium after heat exchange is then discharged. At near-absolute zero temperatures, the adsorption material attached to the cooling umbrella structure adsorbs and condenses gas molecules in the environment, forming a high vacuum environment, achieving a vacuum level of 10... -9A vacuum pressure of Pa achieves a pure vacuum space, making it particularly suitable for the semiconductor industry, where high precision processing is required, such as the processing of heavy metal coatings on chips. When regeneration of the cryogenic vacuum pump is needed, a resistance heater can be used to heat the cooling and vacuum components, releasing molecules adsorbed and solidified on the cold umbrella structure. This facilitates the cleaning and replacement of impurities in the internal cold umbrella and other structures, making operation more convenient.

[0051] In a preferred embodiment, the free end of the secondary cylinder 32 is further provided with a regeneration heating mechanism; more preferably, the regeneration heating mechanism is a resistance heater 6. By providing the resistance heater 6, the refrigeration component 3 and the connected cooling umbrella structure can be heated. When regeneration maintenance of the cryogenic pump is required, and the molecules adsorbed and solidified inside the cooling umbrella are released, the resistance heater is used to heat the cooling umbrella structure, releasing the vacuum, facilitating routine maintenance such as removing impurities or replacing cooling umbrella components, making it more convenient and faster to use.

[0052] Example 2

[0053] Based on the technical solution of Embodiment 1, the adjustment component includes a first valve 51, a first valve stem 52, and a first actuator 53. The first valve 51 is disposed at the open end of the pump housing 1 and is structurally compatible. The first valve stem 52 is fixedly disposed on the first valve 51. The first actuator 53 drives the first valve 51 to reciprocate through the first valve stem 52.

[0054] In a preferred embodiment, the regulating component is provided with a first valve 51. The first valve 51 is opened and closed by driving the movement of the first driver 53, thereby controlling the gas inlet and outlet in the pump housing 1 and regulating the pumping rate and pumping capacity.

[0055] Example 3

[0056] Based on the technical solution of Embodiment 2, the adjustment component further includes a second valve 54, a second valve stem 55, and a second actuator 56. The second valve 54 is located at the outlet of the gas channel, the second valve stem 55 is fixedly mounted on the second valve 54, and the second actuator 56 drives the second valve 54 to reciprocate through the second valve stem 55. The second actuator 56 is fixedly mounted on the outside of the first valve 51, and a displacement hydraulic rod 57 is provided between the first valve 51 and the second valve 54.

[0057] In a more preferred embodiment, the regulating component is further provided with a second valve 54, which is also controlled by an independent actuator to close the gas passage, facilitating subsequent maintenance operations, reducing overall downtime, and improving work efficiency. Preferably, a displacement hydraulic rod 57 is provided between the first valve 51 and the second valve 54 to achieve displacement support between the two valves, ensuring that gas does not enter the cryogenic vacuum pump requiring maintenance. Specifically, the displacement support function is achieved by the displacement hydraulic rod 57 connecting the first valve 51 and the second valve 54. In normal operation mode, the displacement hydraulic rod 57 can move back and forth, and the second actuator 56 moves with the first actuator 53. In fault mode, the displacement hydraulic rod 57 remains in its current position, and the second actuator 56 independently drives the second valve stem 55 to move back and forth. When the pump is running normally, the displacement support function is closed, and the second valve stem 55 moves with the first valve stem 52. When the pump malfunctions, the displacement support function is activated, the second valve 54 closes under the action of an independent actuator, and the first valve 51 also closes, followed by maintenance operations.

[0058] The foregoing has shown and described the basic principles and main features of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments. Therefore, the embodiments should be considered as exemplary and not restrictive. The scope of the present invention is defined by the appended claims rather than the foregoing description. Therefore, it is intended that all variations falling within the meaning and scope of the equivalents of the claims be included within the present invention.

[0059] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A cryogenic vacuum pump with controllable pumping speed and pumping capacity, characterized in that, The application relates to a pump, which comprises a pump shell (1), a vacuum assembly (2), a refrigeration assembly (3) and an adjusting assembly, the vacuum assembly (2) comprises a radiation screen (21) and a cold umbrella structure and is arranged in the pump shell (1), the cold umbrella structure is provided with adsorbing material and is used for adsorbing or condensing gas molecules to form a vacuum environment at low temperature; the refrigeration assembly (3) comprises multi-stage cylinders and is arranged in the vacuum assembly (2) with the free end; refrigeration gas flows in the refrigeration assembly (3) to provide a low-temperature environment for the vacuum assembly (2); and the adjusting assembly is arranged in the pump shell (1) and is located at the gas inlet end to adjust the gas suction rate and capacity.

2. A cryogenic vacuum pump with controllable pumping speed and pumping capacity according to claim 1, characterized in that The radiation screen (21) is fixedly arranged on the inner side wall of the pump shell (1) and is shaped to be matched, a gap is arranged between the outer side wall of the radiation screen (21) and the inner side wall of the pump shell (1), and the bottom end of the radiation screen (21) is provided with a through hole.

3. A cryogenic vacuum pump with controllable pumping speed and pumping capacity according to claim 1, characterized in that, The cold umbrella structure comprises a first barrier plate (22), a second barrier plate (23) and a first cold umbrella (24), the first barrier plate (22) is fixedly arranged at the top end of the inner side wall of the radiation screen (21), the second barrier plate (23) is fixedly arranged on the inner side of the first barrier plate (22), and the first cold umbrella (24) is arranged in the radiation screen (21) and is located below the first barrier plate (22) and the second barrier plate (23).

4. A cryogenic vacuum pump with controllable pumping speed and pumping capacity according to claim 1, characterized in that, The first barrier plate (22) comprises a barrier plate end plate (221) and a barrier plate blade (222), the barrier plate end plate (221) is arranged in a circular ring shape, a plurality of long strip holes (223) are arranged on the barrier plate end plate (221), and the barrier plate blade (222) is arranged at the bottom end of the long strip hole (223).

5. A cryogenic vacuum pump with controllable pumping speed and pumping capacity according to claim 1, characterized in that, The second barrier plate (23) comprises a fixed sheet (231) and a circular ring baffle (232), the fixed sheet (231) is arranged at the axis center position of the radiation screen (21), the circular ring baffle (232) is arranged on the outer side of the fixed sheet (231), and a plurality of circular ring baffles (232) are arranged and the diameters gradually increase from inside to outside.

6. A cryogenic vacuum pump with controllable pumping speed and pumping capacity according to claim 1, characterized in that The first cold umbrella (24) comprises a plurality of cold umbrella sheets and is uniformly arranged from top to bottom, the cold umbrella sheet comprises an end plate (241) and a side plate (242), the side plate (242) is fixedly arranged on the side wall of the end plate (241) and is arranged to be inclined to the end plate (241).

7. A cryogenic vacuum pump with controllable pumping speed and pumping capacity according to claim 1, characterized in that The refrigeration assembly (3) comprises a first-stage cylinder (31) and a second-stage cylinder (32), the first-stage cylinder (31) is provided with a first-stage piston (33), the second-stage cylinder (32) is provided with a second-stage piston (34), the first-stage piston (33) is provided with a driving assembly (35) at the head end and is connected with the second-stage piston (34) at the tail end, and the tail end of the second-stage cylinder (32) is arranged in the cold umbrella structure.

8. A cryogenic vacuum pump with controllable pumping speed and pumping capacity according to claim 1, characterized in that The driving assembly (35) comprises a driving motor (351), an eccentric shaft (352), an eccentric wheel (353) and a driving frame (354), the eccentric shaft (352) is driven to rotate by the driving motor (351), the eccentric wheel (353) is fixedly sleeved on the eccentric shaft (352), the eccentric wheel (353) is arranged in the driving frame (354), and the driving frame (354) is connected with the first end of the primary piston (33).

9. A cryogenic vacuum pump of the kind described in claim 1, characterized in that The adjusting assembly comprises a first valve (51), a first valve rod (52) and a first driver (53), the first valve (51) is arranged at the open end of the pump housing (1) and is structurally matched, the first valve rod (52) is fixedly arranged on the first valve (51), and the first driver (53) drives the first valve (51) to reciprocate through the first valve rod (52).

10. A cryogenic vacuum pump of the kind described in claim 1, characterized in that The adjusting assembly further comprises a second valve (54), a second valve rod (55) and a second driver (56), the second valve (54) is arranged at the gas passage outlet, the second valve rod (55) is fixedly arranged on the second valve (54), the second driver (56) drives the second valve (54) to reciprocate through the second valve rod (55), the second driver (56) is fixedly arranged outside the first valve (51), and the displacement hydraulic rod (57) is arranged between the first valve (51) and the second valve (54).

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