Piston for GM refrigerating machine
By employing a specific combination packing structure in the piston of the GM refrigerator, the cold storage capacity is increased and the extreme bottom temperature is reduced, solving the problem of insufficient cold storage capacity in the prior art and achieving higher refrigeration performance.
Patent Information
- Application Number
- CN202520436304.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-12
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2035-03-12
AI Technical Summary
The existing GM refrigerators have insufficient piston cooling capacity and insufficient extreme bottom temperature, which cannot meet higher performance requirements.
A piston for a GM refrigeration machine is adopted, including a first-stage piston and a second-stage piston. The first-stage piston is equipped with a phosphor bronze perforated plate, a phosphor bronze mesh layer and a cold storage pellet layer. The second-stage piston is equipped with a combination of fillers including a lead pellet layer, a holmium copper mesh layer and a magnetic cold storage pellet layer, which improves the space volume utilization and cold storage capacity, and reduces the extreme bottom temperature through the combination filling.
The cold storage capacity of the GM chiller has been increased, the extreme bottom temperature has been reduced, and higher performance requirements have been met.
Smart Images
Figure CN223647929U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to refrigeration technology, and in particular to a piston for a GM refrigeration machine. Background Technology
[0002] The GM refrigerator is a commercially available, widely used, regenerative, small-scale cryogenic refrigerator. It is extensively applied in cutting-edge technology fields such as semiconductor integrated circuits, flat panel displays, vacuum coating, space environment simulation, and low-temperature superconductivity. The GM refrigerator consists of an expander (cold head), a gas generator (helium compressor unit), and connecting piping. The key component is the cold head, which comprises a valve group gas distribution system, a thin-walled cylinder, a cryogenic accumulator, an exhaust system, a cold-end heat exchanger, and a hot-end heat exchanger. The cryogenic accumulator consists of piston tubes and cryogenic packing. The performance of the GM refrigerator is judged by its cooling capacity, which largely depends on the performance of the first and second stage pistons. The performance of the first and second stage pistons, in turn, largely depends on the performance of the cryogenic packing. Currently, the packing designs for the first and second stage pistons still suffer from insufficient cryogenic capacity and inadequate ultimate bottom temperature, failing to meet higher requirements. Utility Model Content
[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a piston for a GM refrigerator, which has a larger cold storage capacity and a lower limiting bottom temperature.
[0004] A piston for a GM refrigeration unit according to an embodiment of the present invention includes: a primary piston having a primary piston chamber containing a primary cold storage packing; and a secondary piston having one end connected to one end of the primary piston, the secondary piston having a secondary piston chamber containing a secondary cold storage packing; wherein the primary cold storage packing includes a phosphor bronze perforated plate, a first phosphor bronze mesh layer, a primary cold storage pellet layer, and a second phosphor bronze mesh layer arranged sequentially along the piston's axial direction; the secondary cold storage packing includes a first retaining ring, a third phosphor bronze mesh layer, a first support layer, a fourth phosphor bronze mesh layer, a second retaining ring, a lead pellet layer, a first holmium copper mesh layer, a magnetic cold storage pellet layer, a second holmium copper mesh layer, a second support layer, and a third holmium copper mesh layer arranged sequentially along the piston's axial direction; the phosphor bronze perforated plate is located at the end of the primary piston away from the secondary piston, and the first retaining ring is located at the end of the secondary piston closer to the primary piston.
[0005] According to an embodiment of the present invention, a piston for a GM refrigeration unit has at least the following beneficial effects: The first-stage piston adopts a first-stage cold storage pellet layer. Compared with the traditional first-stage piston which uses phosphor bronze mesh filling, the cold storage pellet layer can improve the space volume utilization rate. For the same size piston cavity, "spherical filling" can fill more cold storage material, thereby increasing the cold storage capacity of the first-stage cold head. In addition, the second-stage piston adopts a combination of lead pellet layer, holmium copper mesh layer and magnetic cold storage pellet layer. On the one hand, the pellet layer can increase the cold storage capacity. On the other hand, through the above-mentioned combination filling, the temperature of the second-stage cold head can be effectively reduced, thereby having a lower bottom temperature.
[0006] According to some embodiments of the present invention, the primary cold storage pellet layer is formed by stacking phosphor bronze pellets or stainless steel pellets.
[0007] According to some embodiments of the present invention, the first support layer and the second support layer are wool felt or formed by stacking cold storage nets with a mesh size of 180 mesh or greater.
[0008] According to some embodiments of the present invention, the magnetic cold storage pellet layer is formed by stacking Er3Ni pellets.
[0009] According to some embodiments of this utility model, the height of the phosphor bronze perforated plate is 1±0.5mm, the height of the first phosphor bronze mesh layer is 0.5±0.2mm, the height of the first-stage cold storage pellet layer is 79.3±5mm, the height of the second phosphor bronze mesh layer is 0.5±0.2mm, the mesh size of the phosphor bronze mesh in the first and second phosphor bronze mesh layers is between 150 and 200 mesh, and the particle size of the cold storage pellets in the first-stage cold storage pellet layer is between 0.2mm and 0.5mm.
[0010] According to some embodiments of this utility model, the height of the first retaining ring is 0.2±0.1mm, the height of the third phosphor bronze mesh layer is 0.3±0.2mm, the height of the first support layer is 3±1mm, the height of the fourth phosphor bronze mesh layer is 0.3±0.2mm, the height of the second retaining ring is 0.2±0.1mm, the height of the lead shot layer is 80±5mm, the height of the first holmium copper mesh layer is 0.5±0.2mm, the height of the magnetic cold storage shot layer is 13.7±3mm, and the height of the second holmium copper mesh layer is 0.5±0.2mm. The height of the second support layer is 3±1mm, the height of the third holmium copper mesh layer is 1.0±0.3mm or the height of the third holmium copper mesh layer is equal to the distance from the second support layer to the bottom wall of the corresponding second piston cavity, the mesh size of the phosphor bronze mesh in the third phosphor bronze mesh layer and the fourth phosphor bronze mesh layer is 160±20 mesh, the mesh size of the holmium copper mesh in the first holmium copper mesh layer and the second holmium copper mesh layer is 150±20 mesh, the particle size of the lead shot in the lead shot layer is 0.3±0.05mm, and the particle size of the magnetic cold storage shot in the magnetic cold storage shot layer is 0.2mm to 0.3mm.
[0011] According to some embodiments of the present invention, the diameter of the first-stage piston chamber is 36mm ± 1mm, and the diameter of the second-stage piston chamber is 15mm to 18.5mm.
[0012] According to some embodiments of the present invention, a Green ring seal is provided at the end of the primary piston away from the secondary piston, and at least one primary piston sealing structure is also provided at the position between the two ends of the primary piston, and at least two secondary piston sealing structures are provided at the position between the two ends of the secondary piston.
[0013] According to some embodiments of the present invention, the primary piston sealing structure and the secondary piston sealing structure each include an expansion ring and a piston guide ring, wherein the expansion ring is sleeved on the corresponding piston outer circumference, and the piston guide ring is sleeved on the expansion ring.
[0014] According to some embodiments of the present invention, a bottom pushing block is provided at the tail end of the first-stage piston away from the second-stage piston, and the bottom pushing block is used to seal and fix the Green Ring to the first-stage piston.
[0015] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0016] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0017] Figure 1 This is a perspective view of an embodiment of the present utility model;
[0018] Figure 2 This is an exploded view of an embodiment of the present utility model;
[0019] Figure 3 This is a cross-sectional view of the first-stage piston according to an embodiment of the present invention;
[0020] Figure 4 This is a cross-sectional view of the secondary piston in an embodiment of the present invention.
[0021] Figure label:
[0022] First-stage piston 100, phosphor bronze perforated plate 101, first phosphor bronze mesh layer 102, first-stage cold storage shot layer 103, second phosphor bronze mesh layer 104, Green ring seal 105, first-stage piston sealing structure 106, bottom push block 107.
[0023] Secondary piston 200, first retaining ring 201, third phosphor bronze mesh layer 202, first support layer 203, fourth phosphor bronze mesh layer 204, second retaining ring 205, lead shot layer 206, first holmium copper mesh layer 207, magnetic cold storage shot layer 208, second holmium copper mesh layer 209, second support layer 210, third holmium copper mesh layer 211, secondary piston sealing structure 212;
[0024] Connecting component 300, connecting block 301, primary piston fixing shaft 302, secondary piston fixing shaft 303. Detailed Implementation
[0025] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.
[0026] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 utility model.
[0027] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0028] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.
[0029] Reference Figures 1 to 4 A piston for a GM refrigeration unit includes: a primary piston 100, a secondary piston 200, and a connecting assembly 300. The primary piston 100 has a primary piston chamber containing primary cold storage packing. One end of the secondary piston 200 is connected to one end of the primary piston 100 via the connecting assembly 300. The secondary piston 200 has a secondary piston chamber containing secondary cold storage packing. The connecting assembly 300 includes a connecting block 301, a primary piston fixing shaft 302, and a secondary piston fixing shaft 303.
[0030] In this embodiment, the primary cold storage packing includes a phosphor bronze perforated plate 101, a first phosphor bronze mesh layer 102, a primary cold storage pellet layer 103, and a second phosphor bronze mesh layer 104 arranged sequentially along the axial direction of the piston.
[0031] In this embodiment, the secondary cold storage packing includes a first retaining ring 201, a third phosphor bronze mesh layer 202, a first support layer 203, a fourth phosphor bronze mesh layer 204, a second retaining ring 205, a lead shot layer 206, a first holmium copper mesh layer 207, a magnetic cold storage shot layer 208, a second holmium copper mesh layer 209, a second support layer 210, and a third holmium copper mesh layer 211 arranged sequentially along the piston axial direction. The phosphor bronze perforated plate 101 is located at the end of the primary piston 100 away from the secondary piston 200, and the first retaining ring 201 is located at the end of the secondary piston 200 close to the primary piston 100.
[0032] The pistons described above, the first-stage piston 100 uses a first-stage cold storage pellet layer 103. Compared with the traditional first-stage piston 100 which uses phosphor bronze mesh filling, the cold storage pellet layer can improve the space volume utilization. For the same size piston cavity, "spherical filling" can fill more cold storage material, thereby increasing the cold storage capacity of the first-stage cold head. In addition, the second-stage piston 200 uses a combination of lead pellet layer 206, holmium copper mesh layer and magnetic cold storage pellet layer 208. On the one hand, the pellet layer can increase the cold storage capacity. On the other hand, through the above combination filling, the temperature of the second-stage cold head can be effectively reduced, thus having a lower bottom temperature.
[0033] In this embodiment, the primary cold-storage pellet layer 103 is formed by stacking phosphor bronze pellets or stainless steel pellets. It is conceivable that in some embodiments, the primary cold-storage pellet layer 103 is not limited to the structure described above; for example, it could be made of other materials capable of storing cold.
[0034] In this embodiment, the first support layer 203 and the second support layer 210 are made of wool felt or formed by stacking cold storage mesh with a mesh size of 180 mesh or greater. Using wool felt results in lower costs. Using cold storage mesh can simultaneously increase the cold storage capacity of the piston. In this embodiment, the cold storage mesh can be a stainless steel mesh or a phosphor bronze mesh, etc., that has a cold storage function.
[0035] In this embodiment, the magnetic cold storage pellet layer 208 is formed by stacking Er3Ni pellets. It is conceivable that in some embodiments, the magnetic cold storage pellet layer 208 may also use other magnetic cold storage materials, which can be configured according to the actual situation.
[0036] In this embodiment, the height of the phosphor bronze perforated plate 101 is 1 ± 0.5 mm, the height of the first phosphor bronze mesh layer 102 is 0.5 ± 0.2 mm, the height of the primary cold-storage pellet layer 103 is 79.3 ± 5 mm, the height of the second phosphor bronze mesh layer 104 is 0.5 ± 0.2 mm, the mesh size of the phosphor bronze mesh in the first phosphor bronze mesh layer 102 and the second phosphor bronze mesh layer 104 is between 150 and 200 mesh, and the particle size of the cold-storage pellets in the primary cold-storage pellet layer 103 is between 0.2 mm and 0.5 mm. Using the above-mentioned proportions of primary cold-storage filler results in a large cold-storage capacity.
[0037] In this embodiment, the phosphor bronze perforated plate 101 can be a single piece with a diameter of about 36 mm; the first phosphor bronze mesh layer 102 and the second phosphor bronze mesh layer 104 can each be filled with about 5 pieces (0.1 mm each) with a diameter of about 36 mm.
[0038] In this embodiment, the height of the first retaining ring 201 is 0.2±0.1mm, the height of the third phosphor bronze mesh layer 202 is 0.3±0.2mm, the height of the first support layer 203 (wool felt) is 3±1mm, the height of the fourth phosphor bronze mesh layer 204 is 0.3±0.2mm, the height of the second retaining ring 205 is 0.2±0.1mm, the height of the lead shot layer 206 is 80±5mm, the height of the first holmium copper mesh layer 207 is 0.5±0.2mm, the height of the magnetic cold storage shot layer 208 is 13.7±3mm, the height of the second holmium copper mesh layer 209 is 0.5±0.2mm, and the height of the second support layer 205 is... The height of the 10 (wool felt) layer is 3±1mm; the height of the third holmium copper mesh layer 211 is 1.0±0.3mm, or the height of the third holmium copper mesh layer 211 is equal to the distance from the second support layer 210 to the corresponding bottom wall of the second piston chamber; the mesh size of the phosphor bronze mesh in the third phosphor bronze mesh layer 202 and the fourth phosphor bronze mesh layer 204 is 160±20 mesh; the mesh size of the holmium copper mesh in the first holmium copper mesh layer 207 and the second holmium copper mesh layer 209 is 150±20 mesh; the particle size of the lead shot in the lead shot layer 206 is 0.3±0.05mm; and the particle size of the magnetic cold storage shot in the magnetic cold storage shot layer 208 is 0.2mm to 0.3mm. Using the above-mentioned proportions of secondary cold storage filler results in even lower temperatures.
[0039] In this embodiment, the first retaining ring 201 is filled with a single piece, approximately 16 mm in diameter; the third phosphor bronze mesh layer 202 and the fourth phosphor bronze mesh layer 204 can be filled with about 3 pieces (0.1 mm each), 16 mm in diameter; the first support layer 203 (wool felt) is filled with a diameter of 16 mm; the second retaining ring 205 is filled with a single piece; the weight of the lead shot in the lead shot layer 206 is controlled at 160 g; the first holmium copper mesh layer 207 is filled with about 5 pieces (0.1 mm each), 17.5 mm in diameter; the magnetic cold storage shot layer 208 is filled with a weight of 30 g; the second holmium copper mesh layer 209 is filled with about 5 pieces (0.1 mm each), 17.5 mm in diameter; the second support layer 210 (wool felt) is filled with a diameter of 17.5 mm; the third holmium copper mesh layer 211 is filled with more than 10 pieces (enough to just fill the gap, the number of pieces can be adjusted according to the piston cover), 17.5 mm in diameter.
[0040] In this embodiment, the diameter of the primary piston chamber is 36mm ± 1mm, and the diameter of the secondary piston chamber is between 15mm and 18.5mm.
[0041] In this embodiment, a Green Ring Seal 105 is provided at the end of the primary piston 100 away from the secondary piston 200. At least one primary piston sealing structure 106 is also provided between the two ends of the primary piston 100, and at least two secondary piston sealing structures 212 are provided between the two ends of the secondary piston 200. With this structure, both the primary piston 100 and the secondary piston 200 have multiple seals, which can reduce gas leakage between the primary and secondary pistons, thereby increasing the cold storage capacity and reducing the extreme bottom temperature.
[0042] In this embodiment, both the primary piston sealing structure 106 and the secondary piston sealing structure 212 include an expansion ring and a piston guide ring, respectively. The expansion ring is fitted around the outer circumference of the corresponding piston, and the piston guide ring is fitted around the expansion ring. The above-described sealing structure is simple, easy to implement, and provides reliable sealing. In some embodiments, the primary piston sealing structure 106 and the secondary piston sealing structure 212 are not limited to the above-described structure; they can be configured appropriately according to actual conditions.
[0043] In this embodiment, a bottom pushing block 107 is provided at the tail end of the primary piston 100 away from the secondary piston 200. The bottom pushing block 107 is used to fix the Green ring seal 105 to the primary piston 100. The bottom pushing block 107 can be fixed to the body of the primary piston 100, and then the Green ring seal 105 is fixed by clamping. The above-described structure for fixing the Green ring seal 105 is simple and easy to implement. It is conceivable that the structure for fixing the Green ring seal 105 is not limited to the above-described structure, and can be configured reasonably according to the actual situation.
[0044] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0045] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.
Claims
1. A piston for a GM refrigerator, characterized in that, include: A primary piston (100) is provided with a primary piston chamber, and a primary cold storage packing is provided in the primary piston chamber; A secondary piston (200) is connected at one end to one end of the primary piston (100). The secondary piston (200) is provided with a secondary piston chamber, and a secondary cold storage packing is provided in the secondary piston chamber. The primary cold storage packing includes a phosphor bronze perforated plate (101), a first phosphor bronze mesh layer (102), a primary cold storage pellet layer (103), and a second phosphor bronze mesh layer (104) arranged sequentially along the piston axis. The secondary cold storage packing includes a first retaining ring (201), a third phosphor bronze mesh layer (202), a first support layer (203), a fourth phosphor bronze mesh layer (204), a second retaining ring (205), a lead pellet layer (206), a first holmium copper mesh layer (207), a magnetic cold storage pellet layer (208), a second holmium copper mesh layer (209), a second support layer (210), and a third holmium copper mesh layer (211) arranged sequentially along the piston axis. The phosphor bronze perforated plate (101) is located at the end of the primary piston (100) away from the secondary piston (200), and the first retaining ring (201) is located at the end of the secondary piston (200) close to the primary piston (100).
2. The piston for a GM refrigerator according to claim 1, characterized in that: The primary cold storage pellet layer (103) is formed by stacking phosphor bronze pellets or stainless steel pellets.
3. The piston for a GM refrigerator according to claim 1, characterized in that: The first support layer (203) and the second support layer (210) are wool felt or formed by stacking cold storage nets with a mesh size of 180 or greater.
4. The piston for a GM refrigerator according to claim 1, characterized in that: The magnetic cold storage pellet layer (208) is formed by stacking Er3Ni pellets.
5. The piston for a GM refrigerator according to claim 1, characterized in that: The height of the phosphor bronze perforated plate (101) is 1±0.5mm, the height of the first phosphor bronze mesh layer (102) is 0.5±0.2mm, the height of the first-stage cold storage pellet layer (103) is 79.3±5mm, the height of the second phosphor bronze mesh layer (104) is 0.5±0.2mm, the mesh size of the phosphor bronze mesh in the first phosphor bronze mesh layer (102) and the second phosphor bronze mesh layer (104) is between 150 mesh and 200 mesh, and the particle size of the cold storage pellets in the first-stage cold storage pellet layer (103) is between 0.2mm and 0.5mm.
6. The piston for a GM refrigerator according to claim 1, characterized in that: The height of the first retaining ring (201) is 0.2±0.1mm, the height of the third phosphor bronze mesh layer (202) is 0.3±0.2mm, the height of the first support layer (203) is 3±1mm, the height of the fourth phosphor bronze mesh layer (204) is 0.3±0.2mm, the height of the second retaining ring (205) is 0.2±0.1mm, the height of the lead shot layer (206) is 80±5mm, the height of the first holmium copper mesh layer (207) is 0.5±0.2mm, the height of the magnetic cold storage shot layer (208) is 13.7±3mm, the height of the second holmium copper mesh layer (209) is 0.5±0.2mm, and the height of the second support layer (210) is... The height of the third holmium copper mesh layer (211) is 3±1mm, the height of the third holmium copper mesh layer (211) is 1.0±0.3mm, or the height of the third holmium copper mesh layer (211) is equal to the distance from the second support layer (210) to the corresponding bottom wall of the second piston cavity. The mesh count of the phosphor bronze mesh in the third phosphor bronze mesh layer (202) and the fourth phosphor bronze mesh layer (204) is 160±20 mesh. The mesh count of the holmium copper mesh in the first holmium copper mesh layer (207) and the second holmium copper mesh layer (209) is 150±20 mesh. The particle size of the lead shot in the lead shot layer (206) is 0.3±0.05mm. The particle size of the magnetic cold storage shot in the magnetic cold storage shot layer (208) is 0.2mm to 0.3mm.
7. The piston for a GM refrigerator according to claim 1, characterized in that: The diameter of the first-stage piston chamber is 36mm ± 1mm, and the diameter of the second-stage piston chamber is between 15mm and 18.5mm.
8. The piston for a GM refrigerator according to claim 1, characterized in that: The first-stage piston (100) is provided with a Green ring seal (105) at one end away from the second-stage piston (200), and the first-stage piston (100) is also provided with at least one first-stage piston sealing structure (106) at the position between the two ends, and the second-stage piston (200) is provided with at least two second-stage piston sealing structures (212) at the position between the two ends.
9. The piston for a GM refrigerator according to claim 8, characterized in that: The primary piston sealing structure (106) and the secondary piston sealing structure (212) each include an expansion ring and a piston guide ring. The expansion ring is sleeved on the corresponding piston outer circumference, and the piston guide ring is sleeved on the expansion ring.
10. The piston for a GM refrigerator according to claim 8, characterized in that: A bottom push block (107) is provided at the tail end of the first-stage piston (100) away from the second-stage piston (200), and the bottom push block (107) is used to fix the Green ring seal (105) to the first-stage piston (100).