An integrated linear stirling cryocooler

Abstract

This invention provides an integrated linear Stirling refrigerator, comprising a linear compressor, an expander, and a phase adjustment mechanism. The phase adjustment mechanism includes a phase adjustment cavity formed between the moving parts of the linear compressor and the expanding compressor, enabling the moving parts of the linear compressor to move relative to the moving parts of the expanding compressor within a preset stroke, and rigidly driving the moving parts of the expanding compressor to move synchronously beyond the preset stroke. This invention achieves phase adjustment through the phase adjustment cavity between the linear compressor and the expander. The phase difference between them is achieved solely through mechanical geometric coordination, without relying on elastic elements, independent drives, or electronic control systems. This fundamentally eliminates problems such as fatigue failure and drive malfunctions, significantly improving lifespan and reliability. Furthermore, the phase difference is uniquely determined by the axial dimension of the phase adjustment cavity and is unaffected by temperature or operating conditions, solving the problem of significant refrigeration efficiency degradation in traditional pneumatic linear Stirling refrigerators under varying operating conditions.

Description

Technical Field

[0001] This invention belongs to the field of Stirling refrigerator technology, specifically relating to an integral linear Stirling refrigerator. Background Technology

[0002] Linear Stirling refrigerators are widely used in military and civilian applications such as infrared detection, infrared night vision, and infrared guidance in space and on the ground. Based on the expander arrangement, linear Stirling refrigerators can be divided into separate and integrated types. The former is suitable for applications requiring low vibration and flexible layout, while the latter is suitable for applications with less stringent vibration requirements. The coupling matching efficiency between the compressor and expander has a significant impact on the cooling efficiency of the Stirling refrigerator. In actual operation, the optimal phase of the refrigerator changes in real time with parameters such as ambient temperature, cooling temperature, and heat load. However, the phase adjustment mechanism of traditional linear refrigerators is designed for a single operating condition. When the operating condition changes, the actual operating phase deviates from the optimal phase under that condition, leading to a decrease in coupling matching efficiency and an increase in power consumption. Therefore, achieving a reasonable phase difference between the expander piston displacement and the compressor displacement under varying operating conditions is key to improving coupling matching efficiency.

[0003] Traditional linear Stirling refrigerators typically employ a pneumatic spring oscillator passive phase adjustment structure or a motor-driven active phase adjustment structure. The traditional phase adjustment methods have the following drawbacks: (1) The pneumatic spring oscillator passive phase adjustment structure is prone to fatigue deformation, elastic decay, or even breakage during long-term reciprocating operation, resulting in phase shift, reduced efficiency, and limited reliability and lifespan. Moreover, this phase adjustment mechanism is designed for a single operating condition and has weak phase adjustment capability when the operating condition changes, resulting in a deviation from the optimal operating condition and a decrease in refrigeration efficiency. (2) The motor-driven active phase adjustment structure requires the addition of control and drive components, which results in a complex structure, large size, high energy consumption, many fault points, and control delay. (3) The phase adjustment accuracy of these traditional phase adjustment methods is easily affected by temperature, frequency, and operating condition fluctuations, resulting in poor consistency and difficulty in meeting the requirements of long lifespan, high reliability, and miniaturization. Summary of the Invention

[0004] The purpose of this invention is to provide an integral linear Stirling refrigerator, which can at least solve some of the defects existing in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An integrated linear Stirling refrigerator includes a linear compressor, an expander, and a phase adjustment mechanism. The moving parts of the linear compressor and the moving parts of the expander are arranged coaxially. The phase adjustment mechanism includes a phase adjustment cavity formed between the moving parts of the linear compressor and the moving parts of the expander, enabling the moving parts of the linear compressor to move relative to the moving parts of the expander within a preset stroke, and rigidly driving the moving parts of the expander to move synchronously after exceeding the preset stroke.

[0007] Furthermore, the moving component of the linear compressor is a compression moving cylinder, and the moving component of the expander is a guide piston. The compression moving cylinder is provided with a drive rod on the side facing the expander. One end of the guide piston is provided with a mating cavity that cooperates with the drive rod. The free end of the drive rod is movably limited within the mating cavity and can move axially along the mating cavity. When the drive rod moves to its limit position to the left relative to the mating cavity, the axial gap between the right end face of its free end and the right end face of the mating cavity constitutes the phase adjustment cavity.

[0008] Furthermore, the driving rod is a T-shaped rod, and the mating cavity is a square cavity. An opening is provided on the side of the square cavity near the driving rod for the vertical section of the T-shaped rod to pass through. The horizontal section of the T-shaped rod is located inside the square cavity and can move along its axial direction inside the square cavity.

[0009] Furthermore, the linear compressor also includes a magnet assembly, a winding, and a compressor frame. The magnet assembly is fixed to the outside of the compression moving cylinder, the inside of the compression moving cylinder is clearance-fitted with the compressor frame, and the winding is disposed on the outside of the compressor frame.

[0010] Furthermore, the magnet assembly includes a first main magnet, a first auxiliary magnet, a second main magnet, and a second auxiliary magnet. The first main magnet and the first auxiliary magnet are arranged opposite to each other in the axial direction of the compression moving cylinder and have opposite magnetization directions. The second main magnet and the second auxiliary magnet are arranged opposite to each other in the axial direction of the compression moving cylinder and have opposite magnetization directions. The first main magnet and the second main magnet are both sleeved on the outside of the compression moving cylinder and have opposite magnetization directions. A magnet spacer is provided between the first main magnet and the second main magnet. The first auxiliary magnet and the second auxiliary magnet are respectively fixedly installed at both ends of the compressor frame.

[0011] Furthermore, one end of the guide piston, which has a mating cavity, is fitted into the compressor frame and extends into the interior of the compression moving cylinder.

[0012] Furthermore, the compressor frame includes a connecting plate, an inner cylinder, an outer cylinder, and an end cap. The connecting plate has a central through hole. The inner cylinder and the outer cylinder are perpendicular to the connecting plate and coaxially arranged with the central through hole. The inner cylinder is sleeved inside the compression moving cylinder. The end cap is connected to the end of the outer cylinder away from the connecting plate. The winding is disposed on the outside of the outer cylinder. The expander is connected to the connecting plate.

[0013] Furthermore, the gap between the inner side of the compression moving cylinder and the compressor frame is 5-10 μm.

[0014] Furthermore, the expander includes a guide piston, an integrated Dewar, a cold accumulator, a hot chamber, and a cold chamber. One end of the integrated Dewar is fixedly mounted on the linear compressor by fasteners. The cold accumulator is disposed inside the integrated Dewar. The guide piston is coaxially disposed on the side of the cold accumulator near the linear compressor. The end of the guide piston away from the mating cavity is sealed with a gap to the inner circumferential surface of the integrated Dewar. The hot chamber and the cold chamber are located inside the integrated Dewar. The hot chamber is formed in the cavity of the guide piston near the linear compressor and communicates with the compression chamber of the linear compressor. The cold chamber is formed at the end of the cold accumulator away from the linear compressor.

[0015] Furthermore, the guide piston includes a piston body section and a cold accumulator mating section coaxially connected in sequence. The diameter of the cold accumulator mating section is larger than the diameter of the piston body section. The mating cavity is located at one end of the piston body away from the cold accumulator mating section. The cold accumulator mating section is provided with an airflow channel for connecting the hot cavity and the cold accumulator.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] (1) The integral linear Stirling refrigerator provided by the present invention achieves phase adjustment through the phase adjustment cavity between the linear compressor and the expander. The phase difference between the two is achieved only by mechanical geometric cooperation, without relying on elastic elements, independent drive and electrical control system. This fundamentally eliminates problems such as fatigue failure and drive failure, greatly improves life and reliability. Moreover, the phase difference is uniquely determined by the axial dimension of the phase adjustment cavity and is not affected by temperature or operating conditions. This solves the problem of large refrigeration efficiency decay of traditional pneumatic linear Stirling refrigerators under varying operating conditions.

[0018] (2) The integrated linear Stirling refrigerator provided by this invention eliminates the internal magnetic yoke, compressor plate spring, and expander mechanical spring parts in the traditional integrated Stirling refrigerator. It also replaces the traditional internal and external double-gap sealed compressor piston with a simpler compression moving cylinder, reducing the number of refrigerator parts and achieving a compact layout of the whole machine, which greatly reduces the cost.

[0019] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the integral linear Stirling refrigerator of the present invention;

[0021] Figure 2 This is a schematic diagram of the working process of the integral linear Stirling refrigerator of the present invention;

[0022] Figure 3 This is a comparison diagram of piston motion between an ideal cycle, a conventional actual cycle, and the theoretical cycle of this invention.

[0023] Explanation of reference numerals in the attached drawings: 1. End cap; 2. Compression moving cylinder; 3. First auxiliary magnet; 4. Outer yoke; 5. First main magnet; 6. Winding; 7. Magnet spacer; 8. Second main magnet; 9. Compressor frame; 10. Second auxiliary magnet; 11. Fastening screw; 12. Integrated Dewar; 13. Guide piston; 14. Cold accumulator housing; 15. Cold accumulator packing; 16. Cold cavity; 17. Hot cavity; 18. Phase adjustment cavity; 19. Compression cavity. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", 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.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection", and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, an abutting connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0028] like Figure 1 As shown, this embodiment provides an integrated linear Stirling refrigerator, including a linear compressor, an expander, and a phase-adjusting mechanism. The moving parts of the linear compressor and the expander are arranged coaxially. The phase-adjusting mechanism includes a phase-adjusting cavity 18 formed between the moving parts of the linear compressor and the expander, allowing the moving parts of the linear compressor to move relative to the moving parts of the expander within a preset stroke of the phase-adjusting cavity 18, and rigidly driving the moving parts of the expander to move synchronously after exceeding the preset stroke. Specifically, the preset stroke of the phase-adjusting cavity 18 refers to the effective axial movable space length provided by the phase-adjusting cavity 18 for the moving parts of the linear compressor. This preset stroke is an axial distance pre-designed by the structural dimensions, which corresponds to the designed phase difference between the linear compressor and the expander. The free-stroke movement of the linear compressor relative to the moving parts of the expander within this preset stroke means that when the moving parts of the linear compressor move within this preset stroke range, the moving parts of the expander remain stationary. This free-stroke movement creates a phase difference where the displacement of the linear compressor leads the displacement of the expander, perfectly matching the phase relationship required by the Stirling cycle. In this embodiment, the phase difference between the linear compressor and the expander is predetermined through specific structural design, thereby achieving a fixed phase between the linear compressor and the expander motor structure. This ensures that the refrigeration machine remains in the optimal phase range under varying ambient and refrigeration temperatures, thus keeping the refrigeration machine in a high-efficiency range.

[0029] In one specific embodiment, the moving part of the linear compressor is a compression moving cylinder 2, and the moving part of the expander is a guide piston 13. The compression moving cylinder 2 is provided with a drive rod on the side facing the expander. One end of the guide piston 13 is provided with a mating cavity that cooperates with the drive rod. The free end of the drive rod is limited to the mating cavity and can move axially along the mating cavity. When the drive rod moves to its limit position to the left relative to the mating cavity, the axial gap between the right end face of its free end and the right end face of the mating cavity constitutes the phase-adjusting cavity 18, so that the two form a discontinuous rigid connection. The axial length of this axial gap is the preset stroke of the phase-adjusting cavity 18. In this embodiment, the compression moving cylinder 2 is both a compression component and a phase adjustment drive component. When the compression moving cylinder 2 moves, it first goes through a period of idle stroke (i.e., the phase adjustment cavity 18), during which the guide piston 13 remains stationary, and a phase difference is naturally formed between the linear compressor and the expander. When the compression moving cylinder 2 continues to move, the drive rod contacts the end face of the mating cavity and enters the hard connection stroke, and the compression moving cylinder 2 drives the guide piston 13 to move synchronously. Through the alternation of the idle stroke and the hard connection stroke, the phase adjustment between the displacement of the linear compressor and the displacement of the expander is naturally realized, thereby ensuring the normal operation of the Stirling refrigeration cycle. In this embodiment, the phase adjustment function is integrated into the cooperation structure of the compression moving cylinder 2 and the guide piston 13. The phase adjustment mechanism is integrated with the linear compressor and expander, without external phase adjustment components or additional installation space. While realizing the phase adjustment function, it simplifies the overall structure to the greatest extent, reduces volume and weight, reduces assembly difficulty, and improves structural compactness. Moreover, its phase adjustment only relies on the geometric fit of the rigid mechanical structure. The material properties and structural dimensions are minimally affected by external conditions such as ambient temperature and vibration. It can maintain a stable phase difference under harsh conditions such as wide temperature range and strong vibration, ensuring that the refrigeration unit can work continuously and stably in complex environments.

[0030] Optionally, the drive rod is a T-shaped rod, and the mating cavity is a square cavity. An opening is provided on the side of the square cavity near the drive rod for the vertical section of the T-shaped rod to pass through. The horizontal section of the T-shaped rod is located inside the square cavity and can move axially within the square cavity. Initially, the horizontal section of the T-shaped rod is close to the end face of the mating cavity with the opening. When the compression cylinder 2 moves, the horizontal section of the T-shaped rod moves axially from the end face of the opening to the side face opposite to the opening end within the mating cavity. The axial distance traveled by the horizontal section of the T-shaped rod within the mating cavity is the preset stroke of the phase-adjusting cavity 18.

[0031] As one specific implementation method, such as Figure 1As shown, the linear compressor includes a coaxially assembled compression moving cylinder 2, a magnet assembly, a winding 6, and a compressor frame 9. The compression moving cylinder 2 is a hollow cylindrical structure and is the core moving component of the linear compressor. It also serves as the phase-adjusting drive component of the phase-adjusting mechanism, achieving integrated compression and phase-adjusting drive functions. The winding 6 is a ring coil structure, wound around the outside of the compressor frame 9. Preferably, an outer magnetic yoke 4 is fitted around the winding 6 to concentrate the magnetic field. The two ends of the winding 6 are connected to an external power source, generating an alternating magnetic field after AC current is applied. The magnet assembly is fixed to the outside of the compression moving cylinder 2, and the inner side of the compression moving cylinder 2 is clearance-fitted with the compressor frame 9. The guide piston 13 is equipped with a matching... One end of the cavity section passes through the compressor frame 9 and extends into the compression moving cylinder 2. The inner cylinder of the compressor frame 9 and the guide piston 13 together constitute the compression piston of the linear compressor. The space between the compression piston and the compression moving cylinder 2 forms the compression chamber 19. At the same time, the gap between the inner cylinder of the compressor frame 9 and the guide piston constitutes a gas flow channel connecting the compression chamber 19 and the hot chamber 17 of the expander. In this embodiment, the interaction between the alternating magnetic field and the constant magnetic field of the magnet assembly generates an axial linear electromagnetic force, driving the compression moving cylinder 2 to reciprocate linearly relative to the compression piston along the axial direction, thereby compressing the working gas. This linear compressor structure of the present embodiment eliminates the internal magnetic yoke and compressor plate spring in the traditional integrated Stirling refrigerator, and replaces the traditional double-gap sealed compressor piston with the simpler compression moving cylinder 2, reducing the number of refrigerator parts, achieving a compact layout of the whole machine, and significantly reducing costs.

[0032] In some embodiments, such as Figure 1 As shown, the magnet assembly includes a first main magnet 5, a first auxiliary magnet 3, a second main magnet 8, and a second auxiliary magnet 10; wherein the first main magnet 5, the first auxiliary magnet 3, the second main magnet 8, and the second auxiliary magnet 10 all adopt a permanent magnet ring structure such as neodymium iron boron and have axial magnetization. Figure 1The direction of the arrow indicates the magnetization direction of the magnet from the S pole to the N pole, i.e., the axial magnetization direction. The first main magnet 5 and the first auxiliary magnet 3 are arranged opposite each other in the axial direction of the compression moving cylinder 2 and have opposite magnetization directions. The second main magnet 8 and the second auxiliary magnet 10 are arranged opposite each other in the axial direction of the compression moving cylinder 2 and have opposite magnetization directions. The first main magnet 5 and the second main magnet 8 are both sleeved on the outside of the compression moving cylinder 2 and have opposite magnetization directions. A magnet spacer 7 is provided between the first main magnet 5 and the second main magnet 8. The first auxiliary magnet 3 and the second auxiliary magnet 10 are respectively fixedly installed at both ends of the compressor frame 9 to provide magnetic buffering and limiting function for the first main magnet 5 and the second main magnet 8. When the compression moving cylinder 2 moves to the vicinity of the left / right dead point, the repulsive force between the auxiliary magnet and the main magnet increases sharply, forming a soft limit to prevent mechanical collision between the main magnet, the compression moving cylinder and the end face of the compressor frame. Each magnet and the magnet spacer 7 are fixed to the outer cylindrical surface of the compression moving cylinder 2 by means of, but not limited to, adhesive bonding.

[0033] In some embodiments, the compressor frame 9 is a coaxial sleeve-type integral structure, including a connecting plate, an inner cylinder, an outer cylinder, and an end cap 1. The connecting plate has a central through hole. The inner cylinder and the outer cylinder are perpendicular to the connecting plate and coaxially arranged with the central through hole. The inner cylinder is sleeved in the compression moving cylinder 2. The inner side of the compression moving cylinder 2 is clearance-fitted with the outer surface of the inner cylinder. The end cap 1 is connected to the end of the outer cylinder away from the connecting plate, forming an end seal of the linear compressor. The winding 6 is disposed on the outside of the outer cylinder. The expander is connected to the connecting plate, and the guide piston 13 of the expander is sleeved in the inner cylinder of the compressor frame 9.

[0034] Furthermore, the gap between the inner side of the compression moving cylinder 2 and the compressor frame 9 is 5-10 μm, which ensures that the compression moving cylinder 2 can move freely back and forth along the axial direction, reduces the leakage of working gas, and the inner cylinder can also guide the movement of the compression moving cylinder 2. Preferably, the inner cylindrical surface of the compression moving cylinder 2 is coated with a wear-resistant coating.

[0035] As one specific implementation method, such as Figure 1As shown, the expander includes a guide piston 13, an integrated Dewar 12, a cold accumulator, a hot chamber 17, and a cold chamber 16. One end of the integrated Dewar 12 is fixedly mounted to the linear compressor by fasteners; specifically, the integrated Dewar is fixedly mounted to the compressor frame 9. The cold accumulator is disposed inside the integrated Dewar 12. The guide piston 13 is coaxially disposed on the side of the cold accumulator closer to the linear compressor. The end of the guide piston 13 away from the mating cavity is sealed with the inner circumferential surface of the integrated Dewar 12 to minimize axial air leakage. Optionally, the guide piston 13 is a coaxial cylindrical integral rigid component, including a piston body section and a cold accumulator mating section coaxially connected in sequence. The diameter of the cold accumulator mating section is larger than the diameter of the piston body section, forming a stepped rod structure. The mating cavity is located on the piston body at the end away from the cold accumulator mating section. The cold accumulator mating section is provided with an airflow channel to connect the hot chamber 17 and the cold accumulator. The hot cavity 17 and the cold cavity 16 are located inside the integrated Dewar 12. The hot cavity 17 is formed in the cavity of the guide piston 13 near the linear compressor and communicates with the compression cavity 19 of the linear compressor, so that the working gas pressure inside the compression cavity 19 and the hot cavity 17 is always basically balanced, reducing gas flow loss. The cold cavity 16 is formed at the end of the cold accumulator away from the linear compressor.

[0036] Optionally, the integrated Dewar 12 adopts a cylindrical structure. The integrated Dewar is coaxially arranged with the linear compressor and the guide piston 13. One end of the integrated Dewar 12 adopts an annular flange structure, which is fixedly connected to the corresponding mounting surface of the compressor frame 9 by fastening screws 11. A metal sealing ring is set at the coupling point to form a high-pressure gas sealing structure, which can not only ensure the reliable fixation of the integrated Dewar 12 and the compressor frame 9, but also prevent leakage of the working medium inside the refrigeration machine. The end of the integrated Dewar 12 closer to the linear compressor serves as a heat dissipation end, and the hot cavity 17 is located at the heat dissipation end. The heat generated in the hot cavity 17 is transferred to the environment through this heat dissipation end of the integrated Dewar 12 to realize the heat release process of the Stirling refrigeration cycle. The end of the integrated Dewar 12 away from the linear compressor serves as a vacuum insulation end, and the cold cavity 16 is located at the vacuum insulation end to prevent external heat from being transferred to the cold cavity 16.

[0037] Optionally, the cold storage device includes a cold storage device housing 14 and a cold storage packing 15 filled in the cold storage device housing 14. The cold storage packing 15 has an airflow channel connecting the cold cavity 16 and the hot cavity 17. The cold storage packing 15 can adopt, but is not limited to, a wire mesh structure, to achieve rapid heat exchange between the working gas and the cold storage packing 15 in the refrigeration cycle and complete the regeneration process.

[0038] The working process of the integral linear Stirling refrigerator in this embodiment is as follows: Figure 2 As shown: In processes (a) to (b), AC current is applied to winding 6, and the compression cylinder 2 moves from the left dead center to the right under the action of electromagnetic force, while the guide piston 13 of the expander remains almost stationary at the left dead center. The gas pressure in the compression chamber 19 and the hot chamber 17 increases, which is the compression process of the Stirling refrigeration cycle; In processes (b) to (c), as the compression cylinder 2 continues to move to the right under the action of electromagnetic force, the guide piston 13 is driven to move to the right by the compression cylinder 2 through a rigid connection, which is the compression process of the Stirling refrigeration cycle. The isochoric heat release process of the Stirling refrigeration cycle; in process (c) to process (d), the compression moving cylinder 2 moves from right dead center to left under the action of electromagnetic force, while the guide piston 13 of the expander is almost stationary at right dead center, which belongs to the expansion process of the Stirling refrigeration cycle; in process (d) to process (a), as the compression moving cylinder 2 continues to move to the left under the action of electromagnetic force, the guide piston 13 is driven to move to the left by the compression moving cylinder 2 through a hard connection, which belongs to the isochoric heat absorption process of the Stirling refrigeration cycle.

[0039] Furthermore, the theoretical motion relationship between the compressor moving cylinder 2 and the guide piston 13 in this embodiment is as follows: Figure 3 As shown in (c), the displacement curve of the compressor moving cylinder 2 is a continuous sine wave, while the displacement curve of the guide piston 13 is a segmented broken line. Through the alternation of "no-load stroke + hard connection", four cyclic processes are clearly divided, and its theoretical cycle curve is closer to the ideal cycle (e.g., Figure 3 (as shown in (a)), which greatly improves the cooling efficiency.

[0040] The above examples are merely illustrative of the present invention and do not constitute a limitation on the scope of protection of the present invention. All designs that are the same as or similar to the present invention are within the scope of protection of the present invention.

Claims

1. An integral linear Stirling refrigerator, characterized in that: The device includes a linear compressor, an expander, and a phase adjustment mechanism. The moving parts of the linear compressor and the expanding machine are arranged coaxially. The phase adjustment mechanism includes a phase adjustment cavity formed between the moving parts of the linear compressor and the expanding machine, which enables the moving parts of the linear compressor to move relative to the moving parts of the expanding machine within a preset stroke, and rigidly drives the moving parts of the expanding machine to move synchronously after exceeding the preset stroke.

2. The integral linear Stirling refrigerator as described in claim 1, characterized in that: The moving component of the linear compressor is a compression moving cylinder, and the moving component of the expander is a guide piston. The compression moving cylinder has a drive rod on the side facing the expander. One end of the guide piston has a mating cavity that cooperates with the drive rod. The free end of the drive rod is limited to the mating cavity and can move axially along the mating cavity. When the drive rod moves to its limit position to the left relative to the mating cavity, the axial gap between the right end face of its free end and the right end face of the mating cavity constitutes the phase adjustment cavity.

3. The integral linear Stirling refrigerator as described in claim 2, characterized in that: The drive rod is a T-shaped rod, and the mating cavity is a square cavity. An opening is provided on the side of the square cavity near the drive rod for the vertical section of the T-shaped rod to pass through. The horizontal section of the T-shaped rod is located inside the square cavity and can move along its axial direction inside the square cavity.

4. The integral linear Stirling refrigerator as described in claim 2, characterized in that: The linear compressor also includes a magnet assembly, a winding, and a compressor frame. The magnet assembly is fixed to the outside of the compression moving cylinder, the inside of the compression moving cylinder is clearance-fitted with the compressor frame, and the winding is disposed on the outside of the compressor frame.

5. The integral linear Stirling refrigerator as described in claim 4, characterized in that: The magnet assembly includes a first main magnet, a first auxiliary magnet, a second main magnet, and a second auxiliary magnet. The first main magnet and the first auxiliary magnet are arranged opposite to each other in the axial direction of the compression moving cylinder and have opposite magnetization directions. The second main magnet and the second auxiliary magnet are also arranged opposite to each other in the axial direction of the compression moving cylinder and have opposite magnetization directions. The first main magnet and the second main magnet are both sleeved on the outside of the compression moving cylinder and have opposite magnetization directions. A magnet spacer is provided between the first main magnet and the second main magnet. The first auxiliary magnet and the second auxiliary magnet are respectively fixedly installed at both ends of the compressor frame.

6. The integral linear Stirling refrigerator as described in claim 4, characterized in that: One end of the guide piston, which has a mating cavity, is fitted into the compressor frame and extends into the compression moving cylinder.

7. The integral linear Stirling refrigerator as described in claim 4 or 6, characterized in that: The compressor frame includes a connecting plate, an inner cylinder, an outer cylinder, and an end cap. The connecting plate has a central through hole. The inner cylinder and the outer cylinder are perpendicular to the connecting plate and coaxially arranged with the central through hole. The inner cylinder is sleeved inside the compression moving cylinder. The end cap is connected to the end of the outer cylinder away from the connecting plate. The winding is disposed on the outside of the outer cylinder. The expander is connected to the connecting plate.

8. The integral linear Stirling refrigerator as described in claim 4, characterized in that: The gap between the inner side of the compression moving cylinder and the compressor frame is 5-10 μm.

9. The integral linear Stirling refrigerator as described in claim 2, characterized in that: The expander includes a guide piston, an integrated Dewar, a cold accumulator, a hot chamber, and a cold chamber. One end of the integrated Dewar is fixedly mounted to the linear compressor by fasteners. The cold accumulator is disposed inside the integrated Dewar. The guide piston is coaxially disposed on the side of the cold accumulator near the linear compressor. The end of the guide piston away from the mating cavity is sealed with a gap to the inner circumferential surface of the integrated Dewar. The hot chamber and the cold chamber are located inside the integrated Dewar. The hot chamber is formed in the cavity of the guide piston near the linear compressor and communicates with the compression chamber of the linear compressor. The cold chamber is formed at the end of the cold accumulator away from the linear compressor.

10. The integral linear Stirling refrigerator as described in claim 9, characterized in that: The guide piston includes a piston body section and a cold accumulator mating section connected coaxially in sequence. The diameter of the cold accumulator mating section is larger than the diameter of the piston body section. The mating cavity is located at one end of the piston body away from the cold accumulator mating section. The cold accumulator mating section is provided with an airflow channel for connecting the hot cavity and the cold accumulator.

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