Compression piston assembly and rotary Stirling refrigerator
By using the intake passage on the cylinder periphery wall in the compression piston assembly of the rotary Stirling refrigerator, piston contact wear and noise problems are solved, refrigeration performance is improved, support structure is simplified, and the support structure is eliminated The use of universal bearings.
Patent Information
- Application Number
- CN202420328211.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-21
- Publication Date
- 2025-01-10
- Estimated Expiration
- 2034-02-21
AI Technical Summary
The contact wear between the piston and the cylinder in a rotating Stirling refrigerator causes the coating to fall off and noise, and the radial clearance of the piston movement is uneven due to the eccentric movement of the motor shaft, resulting in compression leakage and low volume efficiency.
A compression piston assembly is designed to realize the reciprocating movement of the piston suspended in the cylinder through a plurality of first intake passages and second intake passages on the peripheral wall of the cylinder, avoid direct contact between the piston and the cylinder, and simplify the Support structure, the use of universal bearings has been eliminated.
It effectively avoids friction between the piston and the cylinder block and coating shedding, reduces noise, improves refrigeration performance, and simplifies the piston support structure, reducing manufacturing accuracy and cost requirements.
Smart Images
Figure CN222333975U_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of Stirling refrigerators, and more particularly to a compression piston assembly and a rotary Stirling refrigerator. Background Art
[0002] Stirling refrigerators are widely used in military aviation systems. With the development of airborne infrared systems in other countries, a high-reliability rotary refrigerator military aviation refrigeration system has gradually been formed, which has the characteristics of compact structure, small size, light weight, and adaptability to various harsh environments. However, there is a certain lateral force in the rotor movement of the rotary Stirling refrigerator rotor assembly. Generally, a balance block structure is selected to alleviate the eccentric movement. However, as the piston continues to reciprocate, the compression piston and the compression cylinder will inevitably contact and wear. The wear-resistant coating on the compression piston is prone to produce coating solid contaminants during the back-and-forth movement, and its service life is greatly tested. In order to improve the refrigeration performance of the refrigerator, extremely high requirements are placed on the gap between the cylinder body and the piston in the piston assembly, the high-efficiency wear-resistant coating, the cylinder piston coaxial alignment technology, and the high-precision bearing support technology.
[0003] The motor of the rotary Stirling refrigerator drives the crank-connecting rod mechanism to drive the compression piston to move. The compressed working fluid is transferred to the cold storage tank for heat exchange. The cold end of the cold storage tank absorbs heat and forms a low-temperature environment in the expansion chamber. The compression piston and the expansion piston are driven by the same crank mechanism, but the eccentric movement of the motor shaft in the rotary refrigerator causes uneven radial clearance of the piston movement, resulting in compression leakage and low volumetric efficiency. The gap between the piston and the cylinder is generally micron-level, which is limited by high-precision processing technology and assembly feasibility. The friction between the piston and the cylinder causes the wear-resistant coating on the compression piston to fall off and produce solid contaminants in the coating. The contaminants enter the unit as they move, affecting the refrigeration performance.
[0004] During the assembly process, the coaxiality of the compression assembly and the rotor assembly must be guaranteed, so the accuracy of the components of the refrigerator is extremely high. At present, the piston alignment technology of the Stirling rotary refrigerator usually uses universal bearings to achieve free sway adaptation movement centering and concentricity. The shaft end distance of the unit must be measured and confirmed before and after the bearing is aligned. However, even if universal bearings are used to achieve self-adaptation, since the piston has no supporting force, there is always hard contact between the piston and the cylinder under rapid movement. Therefore, the components require ultra-high precision, and the concentricity of the piston and bearing, and the piston and cylinder to achieve high efficiency and high reliability performance is a problem that must be solved in the development of refrigerators. Utility Model Content
[0005] In view of the problems existing in the background technology, an object of the present disclosure is to provide a compression piston assembly and a rotary Stirling refrigerator, which can solve the problem of contact wear between the piston and the cylinder body.
[0006] Thus, a compression piston assembly includes a cylinder body and a compression piston, the cylinder body has a cylinder body peripheral wall and a cylinder body end wall, the cylinder body peripheral wall and the cylinder body end wall form a receiving cavity, the compression piston has a compression piston peripheral wall and a compression piston end wall, the compression piston peripheral wall is radially opposite to and spaced from the cylinder body peripheral wall, the compression piston end wall is axially opposite to the cylinder body end wall, and the axial direction is parallel to the horizontal direction; the cylinder body peripheral wall has a first end and a second end opposite to each other in the axial direction, the first end is a free end, and the second end is connected to the cylinder body end wall; the cylinder body peripheral wall is provided with a plurality of first intake channels and a plurality of second intake channels; the plurality of first intake channels and the plurality of second intake channels are circumferentially arranged in the cylinder body peripheral wall in the entire The plurality of first air inlet channels are arranged alternately on the ring; the peripheral wall of the compression piston is radially spaced apart from the peripheral wall of the cylinder body by a gap, and the gap is connected to each first air inlet channel and each second air inlet channel; the plurality of first air inlet channels are configured to: when the end wall of the compression piston moves toward the end wall of the cylinder body to compress the gas in the accommodating cavity, the plurality of first air inlet channels introduce the compressed gas between the end wall of the cylinder body and the end wall of the compression piston into the gap, so that the compression piston is suspended in the cylinder body; the plurality of second air inlet channels are configured to: when the end wall of the compression piston moves away from the end wall of the cylinder body, the plurality of second air inlet channels introduce the compressed gas outside the cylinder body and the compression piston into the gap, so that the compression piston is suspended in the cylinder body.
[0007] A rotary Stirling refrigerator is provided. The rotary Stirling refrigerator comprises the aforementioned compression piston assembly and a closed cavity. The closed cavity encloses the compression piston assembly therein, and the closed cavity is used for pre-introducing compressed gas.
[0008] The beneficial effects of the present disclosure are as follows: In the compression piston assembly and the rotary Stirling refrigerator of the present disclosure, the configuration of the plurality of first air inlet channels and the plurality of second air inlet channels on the peripheral wall of the cylinder body enables the compression piston to be suspended in the cylinder body during the reciprocating motion of the compression piston end wall relative to the cylinder body end wall (i.e., the compression piston end wall moves toward the cylinder body end wall and the compression piston end wall moves away from the cylinder body end wall), and the reciprocating compression piston does not contact the cylinder body, thereby avoiding the friction between the compression piston and the cylinder body during the reciprocating motion, and the shedding of the material on the outer surface of the compression piston peripheral wall caused by the friction (forming solid contaminants) and the noise caused by the friction. In addition, in the compression piston assembly and the rotary Stirling refrigerator of the present disclosure, the configuration of the plurality of first air inlet channels and the plurality of second air inlet channels on the peripheral wall of the cylinder body enables the compression piston to be suspended in the cylinder body during the reciprocating motion of the compression piston end wall relative to the cylinder body end wall, so there is no need to use the universal bearing of the background technology, thereby simplifying the support of the compression piston. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Figure 1 It is a schematic cross-sectional view of a rotary Stirling refrigerator according to the present disclosure, wherein the compression piston end wall is in a state of moving toward the cylinder end wall, wherein the closed cavity is schematically shown by a dotted line.
[0010] Figure 2 is another schematic cross-sectional view of a rotary Stirling refrigerator according to the present disclosure, wherein the compression piston end wall is in a state of moving away from the cylinder end wall, wherein the closed cavity is schematically shown by a dotted line.
[0011] Figure 3 is along Figure 2 A cross-section view taken along line AA.
[0012] Figure 4 is along Figure 2 Cross-sectional view made along line BB.
[0013] Figure 5 yes Figure 1 and Figure 2 Schematic cross-sectional view of the magnetic orientation control structure of a rotary Stirling refrigerator, where the magnetic lines of force are shown as dotted lines.
[0014] The description of the accompanying drawings is as follows.
[0015] 1000 Rotary Stirling Refrigerator 2 Compression Piston
[0016] 100 compression piston assembly 21 compression piston peripheral wall
[0017] 1 Cylinder 22 Compression piston end wall
[0018] 11 G clearance of cylinder wall
[0019] 111 First end 3 compression connecting rod
[0020] 112 second end 31 ring structure
[0021] 113 first air inlet passage 200 rotor assembly
[0022] 113a The first axial channel 4 drives the crankshaft
[0023] 113b first radial channel 5 magnetic orientation control structure
[0024] 114 Second air intake passage 51 Electromagnet
[0025] 114a second axial channel 52 magnetic pole
[0026] 114b Second radial channel 53 winding
[0027] 12 Cylinder end wall 54 displacement sensor
[0028] 13 Accommodating cavity 300 Closed cavity DETAILED DESCRIPTION
[0029] The accompanying drawings show embodiments of the present disclosure, and it will be understood that the disclosed embodiments are merely examples of the present disclosure, and the present disclosure can be implemented in various forms. Therefore, the specific details disclosed herein should not be interpreted as limiting, but merely as the basis for the claims and as a representative basis for teaching ordinary technicians in the field to implement the present disclosure in various ways.
[0030] [Compression piston assembly]
[0031] Reference Figures 1 to 4 , a compression piston assembly 100 according to the present disclosure includes a cylinder 1 and a compression piston 2 .
[0032] The cylinder body 1 has a cylinder body peripheral wall 11 and a cylinder body end wall 12, and the cylinder body peripheral wall 11 and the cylinder body end wall 12 enclose a receiving cavity 13. The compression piston 2 has a compression piston peripheral wall 21 and a compression piston end wall 22, the compression piston peripheral wall 21 is radially opposite to and spaced from the cylinder body peripheral wall 11, and the compression piston end wall 22 is axially opposite to the cylinder body end wall 12, and the axial direction is parallel to the horizontal direction.
[0033] The cylinder peripheral wall 11 has a first end 111 and a second end 112 opposite to each other in the axial direction, the first end 111 is a free end, and the second end 112 is connected to the cylinder end wall 12. The cylinder peripheral wall 11 is provided with a plurality of first air intake channels 113 and a plurality of second air intake channels 114. The plurality of first air intake channels 113 and the plurality of second air intake channels 114 are alternately arranged along the circumferential direction in the cylinder peripheral wall 11 over a whole circle. The compression piston peripheral wall 21 is radially spaced apart from the cylinder peripheral wall 11 by a gap G, and the gap G is connected to each of the first air intake channels 113 and each of the second air intake channels 114.
[0034] The plurality of first air inlet passages 113 are configured to introduce the compressed gas between the cylinder end wall 12 and the compression piston end wall 22 into the gap G when the compression piston end wall 22 moves toward the cylinder end wall 12 to compress the gas in the receiving chamber 13, so that the compression piston 2 is suspended in the cylinder 1. The plurality of second air inlet passages 114 are configured to introduce the compressed gas outside the cylinder 1 and the compression piston 2 into the gap G when the compression piston end wall 22 moves away from the cylinder end wall 12, so that the compression piston 2 is suspended in the cylinder 1.
[0035] In the compression piston assembly 100 of the present disclosure, the configuration of the plurality of first air inlet channels 113 and the plurality of second air inlet channels 114 of the cylinder body peripheral wall 11 realizes that the compression piston 2 is suspended in the cylinder body 1 during the reciprocating motion of the compression piston end wall 22 relative to the cylinder body end wall 12 (i.e., the compression piston end wall 22 moves toward the cylinder body end wall 12 and the compression piston end wall 22 moves away from the cylinder body end wall 12), and the reciprocating compression piston 2 does not contact the cylinder body 1, thereby avoiding the friction between the compression piston 2 and the cylinder body 1 during the reciprocating motion, and the material on the outer surface of the compression piston peripheral wall 21 caused by the friction falling off (forming solid contaminants) and the noise caused by the friction. In addition, in the compression piston assembly 100 of the present disclosure, the configuration of the plurality of first air inlet channels 113 and the plurality of second air inlet channels 114 of the cylinder body peripheral wall 11 realizes that the compression piston 2 is suspended in the cylinder body 1 during the reciprocating motion of the compression piston end wall 22 relative to the cylinder body end wall 12, so it is not necessary to use the universal bearing of the background technology, thereby simplifying the support of the compression piston 2.
[0036] In the compression piston assembly 100 of the present disclosure, since the multiple first intake channels 113 and the multiple second intake channels 114 are alternately arranged circumferentially in the cylinder circumferential wall 11 on a full circle, the compressed gas flows in the gap G, and the effect of the compressed gas in the gap G is radially balanced due to the pressure of the gas connection process, so that the compression piston 2 is always centrally suspended in the cylinder 1 during the reciprocating motion, ensuring the straightness and coaxiality of the cylinder 1 and the compression piston 2, thereby reducing the precision requirements and cost of the compression piston 2 and the compression piston 2 during manufacturing.
[0037] In the compression piston assembly 100 of the present disclosure, as mentioned in the background art, the gap G is in the micrometer order.
[0038] Specifically, in one example, Figure 1 and Figure 2As shown, each first intake channel 113 includes a first axial channel 113a and a plurality of first radial channels 113b. The first axial channel 113a is axially closed between the first end 111 and the second end 112 of the cylinder circumferential wall 11. The plurality of first radial channels 113b are arranged at intervals along the corresponding first axial channel 113a, and the axial span of the plurality of first radial channels 113b covers the stroke of the compression piston end wall 22 moving toward the cylinder end wall 12. Each first radial channel 113b radially extends from the corresponding first axial channel 113a to the inner surface of the cylinder circumferential wall 11 to communicate with the accommodating cavity 13. Each second air inlet channel 114 includes a second axial channel 114a and a plurality of second radial channels 114b, the second axial channel 114a is axially opened at the first end 111 of the cylinder peripheral wall 11, and axially extends from the first end 111 of the cylinder peripheral wall 11 to the bottom position of the cylinder peripheral wall 11 near the cylinder end wall 12, a plurality of second radial channels 114b are arranged at intervals along the corresponding second axial channel 114a, and the axial span of the second radial channel 114b covers the stroke of the compression piston end wall 22 moving away from the cylinder end wall 12, and each second radial channel 114b radially extends from the corresponding second axial channel 114a to the inner surface of the cylinder peripheral wall 11 to communicate with the receiving cavity 13. The gap G is in communication with each first radial channel 113b and each second radial channel 114b. Each first air inlet channel 113 is configured to: when the compression piston end wall 22 moves toward the cylinder end wall 12, the first radial channel 113b in the plurality of first radial channels 113b that is in communication with the portion of the receiving cavity 13 between the cylinder end wall 12 and the compression piston end wall 22 introduces the compressed gas between the cylinder end wall 12 and the compression piston end wall 22 through the first axial channel 113a into the remaining first radial channels 113b in the plurality of first radial channels 113b and then into the gap G, so that the compression piston 2 is suspended in the cylinder 1. Each second air inlet channel 114 is configured to: when the compression piston end wall 22 moves away from the cylinder end wall 12, the second axial channel 114a introduces the compressed gas outside the cylinder 1 and the compression piston 2 at the first end 111 and introduces the compressed gas into the gap G through the plurality of second radial channels 114b, so that the compression piston 2 is suspended in the cylinder 1. By axially closing the first axial channel 113a between the first end 111 and the second end 112 of the cylinder wall 11 and axially opening the second axial channel 114a at the first end 111 of the cylinder wall 11, the timeliness of the reciprocating motion switching of the compression piston 2 and the non-interference of the corresponding compressed gas flow can be achieved.
[0039] like Figure 3 and Figure 4As shown, in one example, the first axial channels 113a of the plurality of first intake channels 113 and the second axial channels 114a of the plurality of second intake channels 114 are arranged at equal intervals along the circumferential direction on the entire circle. In other words, the first axial channels 113a of the plurality of first intake channels 113 are arranged at equal intervals along the circumferential direction on the entire circle, and the second axial channels 114a of the plurality of second intake channels 114 are arranged at equal intervals along the circumferential direction on the entire circle, which further and more reliably enables the compression piston 2 to always be centrally suspended in the cylinder body 1 during the reciprocating motion.
[0040] like Figure 1 and Figure 2 As shown, in one example, the first radial channels 113b of each first air intake channel 113 are arranged at equal intervals in the axial direction; the second radial channels 114b of each second air intake channel 114 are arranged at equal intervals in the axial direction. This allows the compression piston 2 to be more stably suspended in the cylinder body 1 along the axial direction during the reciprocating motion.
[0041] like Figure 1 and Figure 2 As shown, in one example, the plurality of second radial channels 114b of each second air inlet channel 114 are alternately arranged in the axial direction with the plurality of first radial channels 113b of the corresponding adjacent first air inlet channel 113. Thus, the cylinder peripheral wall 11 is fully utilized without increasing the size of the cylinder peripheral wall 11, thereby ensuring the miniaturization of the compression piston assembly 100.
[0042] Comparison Figure 1 and Figure 2 And compare Figure 3 and Figure 4 In one example, the first axial channel 113a of each first air inlet channel 113 is radially close to the cylinder circumferential wall 11 relative to the second axial channel 114a of the adjacent second air inlet channel 114. As mentioned above, when the compression piston end wall 22 moves toward the cylinder end wall 12, the first radial channel 113b in the plurality of first radial channels 113b that is connected to the portion of the receiving cavity 13 between the cylinder end wall 12 and the compression piston end wall 22 introduces the compressed gas between the cylinder end wall 12 and the compression piston end wall 22 through the first axial channel 113a into the remaining first radial channels 113b in the plurality of first radial channels 113b and then into the gap G, because this flow path is easier than Figure 2The introduction of multiple second radial channels 114b from the second axial channel 114a when the compression piston end wall 22 moves away from the cylinder end wall 12 is not only complicated but also long. Therefore, the first axial channel 113a of each first intake channel 113 is radially close to the cylinder peripheral wall 11 relative to the second axial channel 114a of the adjacent second intake channel 114, so that the compressed gas between the cylinder end wall 12 and the compression piston end wall 22 will flow rapidly to the gap G when the compression piston end wall 22 moves toward the cylinder end wall 12.
[0043] As 1 and Figure 2 As shown, in one example, the compression piston assembly 100 further includes a compression connecting rod 3, which extends horizontally, and one end of which is fixedly connected to the compression piston end wall 22; the compression connecting rod 3 is coaxially arranged with the compression piston 2. One end of the compression connecting rod 3 is fixedly connected to the compression piston end wall 22, providing support for the compression piston 2 without adopting the universal bearing of the background technology, thereby simplifying the support structure of the compression piston 2.
[0044] [Rotary Stirling Refrigerator]
[0045] Reference Figure 1 and Figure 2 According to the present disclosure, the rotary Stirling refrigerator 1000 includes the aforementioned compression piston assembly 100 and a closed cavity 300. The closed cavity 300 encloses the compression piston assembly 100, and the closed cavity 300 is used to pre-enter the compressed gas. The compressed gas in the closed cavity 300 can be introduced by an opening and closing interface.
[0046] Due to the adoption of the compression piston assembly 100 , the rotary Stirling refrigerator 1000 according to the present disclosure has the same effects, structure and operation as described above, so the description of the compression piston assembly 100 is omitted here.
[0047] In one example, refer to Figure 1 , Figure 2 and Figure 5The rotary Stirling refrigerator 1000 also includes a rotor assembly 200, which includes a transmission crankshaft 4 and a magnetic orientation control structure 5. The transmission crankshaft 4 extends vertically. The magnetic orientation control structure 5 is arranged around the transmission crankshaft 4 and fixed to the transmission crankshaft 4. The compression piston assembly 100 also includes a compression connecting rod 3, which extends horizontally. The compression connecting rod 3 is arranged vertically with the transmission crankshaft 4. One end of the compression connecting rod 3 is fixedly connected to the compression piston end wall 22, and the other end of the compression connecting rod 3 is provided with a circular ring structure 31, which is coaxially arranged with the transmission crankshaft 4 and makes the magnetic orientation control structure 5 embedded between the circular ring structure 31 and the transmission crankshaft 4. The magnetic orientation control structure 5 is used to make the circular ring structure 31 of the compression connecting rod 3 radially suspend around the magnetic orientation control structure 5. By using the magnetic orientation control structure 5, the annular structure 31 of the compression connecting rod 3 is radially suspended around the magnetic orientation control structure 5, thereby ensuring the coaxiality of the compression connecting rod 3 of the compression piston assembly 100 and the transmission crankshaft 4 of the rotor assembly 200 (in other words, suppressing the eccentricity of the transmission crankshaft 4), reducing the manufacturing accuracy and cost of the compression connecting rod 3 and the transmission crankshaft 4, and eliminating the noise generated by physical contact.
[0048] Specifically, in one example, Figure 5 As shown, the magnetic orientation control structure 5 is a magnetic suspension structure; the magnetic orientation control structure 5 includes an electromagnet 51, a plurality of magnetic poles 52, a plurality of windings 53, and a displacement sensor 54; the electromagnet 51 surrounds the transmission crankshaft 4 and is fixed to the transmission crankshaft 4; the plurality of magnetic poles 52 are arranged alternately with N poles and S poles along the circumference of the electromagnet 51, and each winding 53 is wound on the corresponding magnetic pole 52; the displacement sensor 54 is arranged in the circumferential interval between two adjacent magnetic poles 52 with opposite polarities to detect the radial gap between the plurality of magnetic poles 52 and the annular structure 31. By setting the displacement sensor 54, it is ensured that the radial gap between the plurality of magnetic poles 52 and the annular structure 31 is monitored in real time and the current flowing in the plurality of windings 53 is controlled based on the monitoring result to ensure the coaxiality of the compression connecting rod 3 of the compression piston assembly 100 and the transmission crankshaft 4 of the rotor assembly 200.
[0049] like Figure 1 and Figure 2 As shown, the closed cavity 300 also encloses a portion of the transmission crankshaft 4 , the compression connecting rod 3 , and the magnetic orientation control structure 5 .
[0050] The above detailed description is used to describe multiple exemplary embodiments, but this document is not intended to be limited to the explicitly disclosed combinations. Therefore, unless otherwise stated, the various features disclosed herein can be combined together to form multiple additional combinations that are not shown for the sake of simplicity.
Claims
1. A compression piston assembly, comprising a cylinder (1) and a compression piston (2), The cylinder body (1) comprises a cylinder body peripheral wall (11) and a cylinder body end wall (12), wherein the cylinder body peripheral wall (11) and the cylinder body end wall (12) enclose a receiving cavity (13). The compression piston (2) comprises a compression piston peripheral wall (21) and a compression piston end wall (22), wherein the compression piston peripheral wall (21) is radially opposite to and spaced from the cylinder peripheral wall (11), and the compression piston end wall (22) is axially opposite to the cylinder end wall (12), and the axial direction is parallel to the horizontal direction; It is characterized in that The cylinder body peripheral wall (11) has a first end (111) and a second end (112) which are opposite to each other in the axial direction, the first end (111) is a free end, and the second end (112) is connected to the cylinder body end wall (12); The peripheral wall (11) of the cylinder body is provided with a plurality of first air intake passages (113) and a plurality of second air intake passages (114); The plurality of first air intake passages (113) and the plurality of second air intake passages (114) are alternately arranged along the circumferential direction on the cylinder peripheral wall (11) over the entire circle; A gap (G) is radially spaced between the compression piston peripheral wall (21) and the cylinder body peripheral wall (11), and the gap (G) is communicated with each first air intake channel (113) and each second air intake channel (114); The plurality of first air inlet passages (113) are configured to: when the compression piston end wall (22) moves toward the cylinder end wall (12) to compress the gas in the receiving chamber (13), the plurality of first air inlet passages (113) introduce the compressed gas between the cylinder end wall (12) and the compression piston end wall (22) into the gap (G), so that the compression piston (2) is suspended in the cylinder (1); The plurality of second air inlet passages (114) are configured to introduce compressed gas outside the cylinder body (1) and the compression piston (2) into the gap (G) when the compression piston end wall (22) moves away from the cylinder body end wall (12), so as to allow the compression piston (2) to be suspended in the cylinder body (1).
2. The compression piston assembly according to claim 1, characterized in that Each first air inlet channel (113) comprises a first axial channel (113a) and a plurality of first radial channels (113b), wherein the first axial channel (113a) is axially closed between a first end (111) and a second end (112) of a cylinder body peripheral wall (11), wherein the plurality of first radial channels (113b) are arranged at intervals along the corresponding first axial channel (113a), and the axial span of the plurality of first radial channels (113b) covers the stroke of the compression piston end wall (22) moving toward the cylinder body end wall (12), and wherein each first radial channel (113b) radially extends from the corresponding first axial channel (113a) to the inner surface of the cylinder body peripheral wall (11) to communicate with the receiving cavity (13); Each second air inlet channel (114) comprises a second axial channel (114a) and a plurality of second radial channels (114b); the second axial channel (114a) is axially opened at the first end (111) of the cylinder circumferential wall (11) and axially extends from the first end (111) of the cylinder circumferential wall (11) to the bottom position of the cylinder circumferential wall (11) close to the cylinder end wall (12); the plurality of second radial channels (114b) are arranged at intervals along the corresponding second axial channel (114a) and the axial span of the second radial channel (114b) covers the stroke of the compression piston end wall (22) moving away from the cylinder end wall (12); each second radial channel (114b) radially extends from the corresponding second axial channel (114a) to the inner surface of the cylinder circumferential wall (11) to communicate with the receiving cavity (13); The gap (G) is in communication with each first radial channel (113b) and each second radial channel (114b); Each first air inlet channel (113) is configured to: when the compression piston end wall (22) moves toward the cylinder end wall (12), the first radial channel (113b) in the plurality of first radial channels (113b) that is in communication with the portion of the receiving cavity (13) between the cylinder end wall (12) and the compression piston end wall (22) introduces the compressed gas between the cylinder end wall (12) and the compression piston end wall (22) through the first axial channel (113a) into the remaining first radial channels (113b) in the plurality of first radial channels (113b) and then into the gap (G), so that the compression piston (2) is suspended in the cylinder (1); Each second air inlet passage (114) is configured to: when the compression piston end wall (22) moves away from the cylinder end wall (12), the second axial passage (114a) introduces compressed gas outside the cylinder (1) and the compression piston (2) at the first end (111) and introduces the compressed gas into the gap (G) via a plurality of second radial passages (114b), so that the compression piston (2) is suspended in the cylinder (1).
3. The compression piston assembly according to claim 2, characterized in that The first axial channels (113a) of the plurality of first air inlet channels (113) and the second axial channels (114a) of the plurality of second air inlet channels (114) are arranged at equal intervals along the entire circle in the circumferential direction.
4. The compression piston assembly according to claim 2, characterized in that The plurality of first radial channels (113b) of each first air inlet channel (113) are arranged at equal intervals in the axial direction; The plurality of second radial passages (114b) of each second air intake passage (114) are arranged at equal intervals in the axial direction.
5. The compression piston assembly according to claim 4, characterized in that The plurality of second radial channels (114b) of each second air intake channel (114) and the plurality of first radial channels (113b) of the corresponding adjacent first air intake channel (113) are alternately arranged in the axial direction.
6. The compression piston assembly according to claim 2, characterized in that The first axial channel (113a) of each first air intake channel (113) is closer to the cylinder circumferential wall (11) in the radial direction relative to the second axial channel (114a) of the adjacent second air intake channel (114).
7. The compression piston assembly according to claim 1, characterized in that The compression piston assembly (100) further comprises a compression connecting rod (3), The compression connecting rod (3) extends horizontally, and one end of the compression connecting rod (3) is fixedly connected to the compression piston end wall (22); The compression connecting rod (3) is coaxially arranged with the compression piston (2).
8. A rotary Stirling refrigerator (1000), characterized in that: A rotary Stirling refrigerator comprises a compression piston assembly (100) and a closed chamber (300) according to any one of claims 1 to 6; The closed cavity (300) encloses the compression piston assembly (100) therein, and the closed cavity (300) is used to be pre-filled with compressed gas.
9. The rotary Stirling refrigerator according to claim 8, characterized in that: The rotary Stirling refrigerator (1000) further comprises a rotor assembly (200), wherein the rotor assembly (200) comprises a transmission crankshaft (4) and a magnetic orientation control structure (5); The transmission crankshaft (4) extends vertically; The magnetic orientation control structure (5) is arranged around the transmission crankshaft (4) and is fixed to the transmission crankshaft (4); The compression piston assembly (100) further comprises a compression connecting rod (3), the compression connecting rod (3) extending horizontally, the compression connecting rod (3) and the transmission crankshaft (4) arranged vertically, one end of the compression connecting rod (3) being fixedly connected to the compression piston end wall (22), the other end of the compression connecting rod (3) being provided with a circular ring structure (31), the circular ring structure (31) being arranged coaxially with the transmission crankshaft (4) and the magnetic orientation control structure (5) being embedded between the circular ring structure (31) and the transmission crankshaft (4); The magnetic orientation control structure (5) is used to make the annular structure (31) of the compression connecting rod (3) radially suspend around the magnetic orientation control structure (5).
10. The rotary Stirling refrigerator according to claim 9, characterized in that: The magnetic orientation control structure (5) is a magnetic suspension structure; The magnetic orientation control structure (5) comprises an electromagnet (51), a plurality of magnetic poles (52), a plurality of windings (53), and a displacement sensor (54); The electromagnet (51) surrounds the transmission crankshaft (4) and is fixed to the transmission crankshaft (4); A plurality of magnetic poles (52) are arranged alternately with N poles and S poles along the circumference of the electromagnet (51). Each winding (53) is wound around a corresponding magnetic pole (52); The displacement sensor (54) is arranged in the circumferential interval between two adjacent magnetic poles (52) with opposite polarities to detect the radial gap between the plurality of magnetic poles (52) and the annular structure (31).