Stirling refrigerator

Abstract

The Stirling cryocooler provided by the embodiment of the invention relates to the technical field of refrigeration equipment, and comprises a driving assembly comprising a crankshaft and a driving structure, the crankshaft comprises a center shaft and an eccentric shaft which are connected with each other, and the driving structure is used for driving the center shaft to rotate; the compression assembly comprises a compression connecting rod, a compression piston and a plurality of first bearings, the first bearings are arranged at intervals in the axial direction of the eccentric shaft, the compression connecting rod comprises a first connecting end and a second connecting end, the first connecting end is provided with a containing cavity, the containing cavity is matched with the peripheries of the first bearings, and the second connecting end is provided with a second connecting end; the second connecting end is rotationally connected with the compression piston, and the first connecting end comprises a first connecting part; and the expansion assembly comprises an expansion piston, and the expansion piston is connected with the first connecting part. According to the Stirling cryocooler, the service life of the first bearing can be effectively prolonged, so that the service life of the whole Stirling cryocooler is effectively prolonged, and the reliability of the Stirling cryocooler is improved.

Description

Technical Field

[0001] The present application relates to the technical field of refrigeration equipment, and in particular to a Stirling refrigerator. Background Art

[0002] In the related art, Stirling refrigerators can be divided into two categories, namely, split Stirling refrigerators and integral Stirling refrigerators, according to their different structures and working modes.

[0003] Split Stirling refrigerator: Compared with the integral Stirling refrigerator, the split Stirling refrigerator installs the compression and expansion pistons in two different units, connected by a thin tube. This design overcomes the impact of vibration and heat generated by the integral Stirling refrigerator on precision instruments such as infrared detectors. It is difficult to produce and has a high price, and is only widely used in the military, aerospace and other fields.

[0004] Integrated Stirling refrigerator: All key components are integrated into a compact unit, including compression components, expansion components, drive components, control systems and necessary auxiliary structures. Its working principle is to achieve the refrigeration effect through the expansion and compression cycle of gas. It has the advantages of high efficiency, small size and low cost. It is the mainstream product currently promoted in the market. The prior art proposes an integrated Stirling refrigerator, which uses a rotary motor to drive the crank connecting rod, and then converts it into a linear motion of the driving piston. In this structure, the rotary support structure of the refrigerator is prone to failure, which affects its service life. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a Stirling refrigerator, which can reduce the probability of premature failure of the rotary support structure and improve the reliability of the integral Stirling refrigerator.

[0006] The present application provides a Stirling refrigerator, comprising:

[0007] A driving assembly, comprising a crankshaft and a driving structure, wherein the crankshaft comprises a central shaft and an eccentric shaft connected to each other, and the driving structure is used to drive the central shaft to rotate;

[0008] A compression assembly, comprising a compression connecting rod, a compression piston and a plurality of first bearings, wherein the plurality of first bearings are arranged at intervals along the axial direction of the eccentric shaft, the compression connecting rod comprises a first connecting end and a second connecting end, the first connecting end has a receiving cavity, the receiving cavity cooperates with the outer periphery of each of the first bearings, the second connecting end is rotatably connected to the compression piston, wherein the first connecting end comprises a first connecting portion;

[0009] The expansion assembly includes an expansion piston connected to the first connection portion.

[0010] Furthermore, a bearing isolation ring is arranged between two adjacent first bearings.

[0011] Furthermore, the first bearings include two, and the two first bearings are spaced apart from each other along the axial direction of the eccentric shaft.

[0012] Furthermore, the compression assembly includes a compression piston pin and a compression piston bearing sleeved on the compression piston pin, and the second connecting end is connected to the compression piston pin through the compression piston bearing.

[0013] Furthermore, the compression assembly includes a compression stabilizing spring pin and a compression stabilizing spring, the compression stabilizing spring pin is connected to the compression connecting rod, the compression stabilizing spring is sleeved on the compression connecting rod, and the compression stabilizing spring is located between the compression stabilizing spring pin and the compression piston bearing, wherein the compression stabilizing spring is in a compressed state.

[0014] Furthermore, the expansion assembly includes a connecting piece, an expansion bearing pin and an expansion assembly connecting pin, one end of the connecting piece is rotationally connected to the expansion piston through the expansion bearing pin, and the other end of the connecting piece is rotationally connected to the first connecting end through the expansion assembly connecting pin.

[0015] Furthermore, the expansion assembly includes an expansion stabilizing spring, and the expansion stabilizing spring is arranged between the expansion bearing pin and the expansion assembly connecting pin.

[0016] Further, the expansion assembly comprises a regenerator shell, and the regenerator shell is rigidly connected to the expansion piston; or, the regenerator shell is connected to the expansion piston via a flexible joint.

[0017] Furthermore, the driving structure includes a stator and a rotor, the rotor is connected to the central shaft, and an air gap is formed between the rotor and the stator.

[0018] Furthermore, the drive assembly also includes a crankshaft balance block, and the crankshaft balance block is installed on the central shaft.

[0019] It can be seen from the above technical solutions that the embodiments of the present application have at least the following beneficial effects:

[0020] In the Stirling refrigerator provided in the embodiment of the present application, multiple first bearings are used to form the dynamic bearing of the compression connecting rod to bear the forces from the compression component and the expansion component. Through the cooperation of multiple first bearings and the compression connecting rod, the bearing capacity of each first bearing is reduced compared to the bearing capacity of the original single bearing, which greatly reduces the load on the first bearing. Therefore, the life of the first bearing can be effectively improved, thereby effectively improving the life of the entire machine. At the same time, while bearing the load of the compression component, the multiple first bearings also bear the load from the expansion component, which can ensure the consistency and compactness of the appearance of the new and old products without changing the external dimensions of the existing products. In the embodiment of the present application, the force form of the rotary drive is optimized to reduce the probability of premature failure of the first bearing; the motion state of the friction pair is also optimized, which is conducive to improving the reliability of the Stirling refrigerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 A partial structural schematic diagram of a Stirling refrigerator provided in one embodiment of the present application;

[0023] Figure 2 A schematic cross-sectional view of a partial structure of a Stirling refrigerator provided in one embodiment of the present application;

[0024] Figure 3 A schematic diagram of a portion of the structure of a drive structure in a Stirling refrigerator provided by an embodiment of the present application;

[0025] Figure 4 for Figure 3 A cross-sectional schematic diagram of

[0026] Figure 5 A schematic diagram of a portion of the structure of a drive assembly in a Stirling refrigerator provided in one embodiment of the present application;

[0027] Figure 6 A schematic diagram of the coordination of a compression component and an expansion component in a Stirling refrigerator provided in one embodiment of the present application;

[0028] Figure 7 A schematic diagram of the structure of a compression assembly in a Stirling refrigerator provided in one embodiment of the present application;

[0029] Figure 8 for Figure 7 Schematic diagram of the cross-section structure;

[0030] Fig. 9 A schematic cross-sectional view of an expansion assembly in a Stirling refrigerator provided in one embodiment of the present application;

[0031] Fig.10 A schematic diagram of the structure of an expansion assembly in a Stirling refrigerator provided in another embodiment of the present application;

[0032] Fig.11 A schematic structural diagram of an expansion assembly in a Stirling refrigerator provided in yet another embodiment of the present application.

[0033] Reference numerals:

[0034] 110, crankshaft; 111, central shaft; 112, eccentric shaft; 120, driving structure; 121, rotor; 122, stator; 123, housing; 124, control circuit; 130, crankshaft balance block;

[0035] 211, first connecting end; 2111, first connecting portion; 220, compression piston; 230, first bearing; 240, compression piston pin; 250, compression stabilizing spring pin; 260, compression stabilizing spring; 270, bearing isolation ring; 280, compression piston bearing;

[0036] 310, expansion piston; 320, connecting piece; 330, regenerator shell; 340, expansion bearing pin; 350, expansion piston connecting bearing; 351, needle bearing; 352, ball bearing; 360, expansion assembly connecting pin; 370, expansion stabilizing spring; 380, flexible hinge. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0038] In the related technology, the Stirling refrigerator is a thermodynamic cycle refrigerator based on the Stirling cycle, which has a profound background technology and is full of innovation. The Stirling cycle, first proposed by a Scottish engineer in 1816, is a thermodynamic cycle consisting of two isothermal processes and two isochoric regenerative processes. This cycle was originally designed for heat engines, but its reverse cycle is used for refrigeration, laying the foundation for the Stirling refrigerator.

[0039] In modern times, Stirling refrigerators have gradually emerged in the field of refrigeration technology, especially in the field of low-temperature refrigeration. Stirling refrigerators have been widely used in many fields due to their high efficiency, environmental protection, pollution-free and high reliability. In the electronics industry, Stirling refrigerators are used to manufacture cryogenic pump devices and liquefied gas devices; in the field of aerospace technology, split Stirling refrigerators are favored for their low vibration and low noise characteristics; in the biological freezing industry, pistonless Stirling refrigerators have become the preferred solution for on-site storage and protection of vaccines and biological samples due to their simple structure, high efficiency and high reliability. In the field of infrared technology, Stirling refrigerators have been widely used in the field of refrigerated infrared detectors due to their small size and high efficiency.

[0040] According to their structure and working mode, Stirling refrigerators can be divided into two categories: split Stirling refrigerators and integral Stirling refrigerators.

[0041] Split Stirling refrigerator: Compared with the integral Stirling refrigerator, the split Stirling refrigerator installs the compression and expansion pistons in two different units, connected by a thin tube. This design overcomes the impact of vibration and heat generated by the integral Stirling refrigerator on precision instruments such as infrared detectors. It is difficult to produce and has a high price, and is only widely used in the military, aerospace and other fields.

[0042] Integrated Stirling refrigerator: All key components are integrated into a compact unit, including compression components, expansion components, drive components, control systems and necessary auxiliary structures. Its working principle is to achieve the refrigeration effect through the expansion and compression cycle of gas. It has the advantages of high efficiency, small size and low cost. It is the mainstream product currently promoted in the market. The prior art proposes an integrated Stirling refrigerator, which uses a rotating motor to drive the crank connecting rod, and then converts it into a linear motion of the driving piston. In this structure, the main reasons for the failure of this refrigerator are the friction and wear failure of the compression piston and the limited bearing capacity of the bearing supporting the piston movement, which affects its service life.

[0043] In view of this, an embodiment of the present application proposes a Stirling refrigerator to effectively solve the aforementioned problem.

[0044] See also Figure 1 and Figure 2 As shown, an embodiment of the present application discloses a Stirling refrigerator, including a drive assembly, a compression assembly and an expansion assembly.

[0045] Specifically, the drive assembly includes a crankshaft 110 and a drive structure 120, the crankshaft 110 includes a central shaft 111 and an eccentric shaft 112 connected to each other, and the drive structure 120 is used to drive the central shaft 111 to rotate; the compression assembly includes a compression connecting rod, a compression piston 220 and a plurality of first bearings 230, the plurality of first bearings 230 are arranged at intervals along the axial direction of the eccentric shaft 112, the compression connecting rod includes a first connecting end 211 and a second connecting end, the first connecting end 211 has a accommodating cavity, the accommodating cavity cooperates with the outer periphery of each first bearing 230, and the second connecting end is rotatably connected to the compression piston 220, wherein the first connecting end 211 includes a first connecting portion 2111; the expansion assembly includes an expansion piston 310, and the expansion piston 310 is connected to the first connecting portion 2111.

[0046] The movement direction of the compression piston 220 and the movement direction of the expansion piston 310 are arranged at a certain angle.

[0047] In this embodiment, the angle between the movement direction of the compression piston 220 and the movement direction of the expansion piston 310 is 90°.

[0048] In the Stirling refrigerator provided in the embodiment of the present application, multiple first bearings 230 are used to form the dynamic bearing of the compression connecting rod, and bear the forces from the compression component and the expansion component at the same time. Through the rigid cooperation between the multiple first bearings 230 and the compression connecting rod, the bearing capacity of each bearing is reduced compared to the bearing capacity of the original single bearing, which greatly reduces the bearing load. Therefore, the life of the first bearing 230 can be effectively improved, thereby effectively improving the life of the entire machine. At the same time, while bearing the load of the compression component, the multiple first bearings 230 also bear the load from the expansion component, which can ensure the consistency and compactness of the appearance of the new and old products without changing the external dimensions of the existing products.

[0049] In the embodiment of the present application, the force form of the rotary drive is optimized to reduce the probability of premature failure of the first bearing 230; the motion state of the friction pair is also optimized, which is beneficial to improving the reliability of the Stirling refrigerator.

[0050] In one embodiment of the present application, the crankshaft 110 performs rotational motion along the center line of the central shaft 111, and the eccentric shaft 112 performs rotational eccentric motion around the center line of the central shaft 111 driven by the central shaft 111. In this embodiment, the driving structure 120 can drive the compression assembly and the expansion assembly to perform linear motion along their respective motion directions by driving the central shaft 111 to rotate.

[0051] In some embodiments of the present application, a bearing isolation ring 270 is provided between two adjacent first bearings 230 to avoid mutual interference between adjacent first bearings 230 and ensure that each first bearing 230 operates independently.

[0052] In this embodiment, see Figure 2 The first bearing 230 includes two bearings, which are arranged at intervals along the axial direction of the eccentric shaft 112, and a bearing isolation ring 270 is arranged between the two first bearings 230. Among them, the two first bearings 230 are both arranged in the accommodating cavity of the first connecting end 211. In this way, the first connecting end 211 can be rotatably connected to the eccentric shaft 112 through the first bearing 230. Through the rigid cooperation of the two first bearings and the compression connecting rod, the bearing capacity of each existing first bearing 230 is only 50% of the original single bearing bearing capacity, which greatly reduces the bearing load. Therefore, the bearing life here can be effectively improved, that is, the life of the whole machine is effectively improved. At the same time, while reducing the bearing capacity, this structure also assumes the function of connecting with the expansion component, which can ensure the appearance consistency and compactness of the new and old products without changing the external dimensions of the existing products.

[0053] In some embodiments of the present application, see Figure 2 , Figure 7 and Figure 8 The compression assembly includes a compression piston pin 240 and a compression piston bearing 280 sleeved on the compression piston pin 240 , and the second connecting end is connected to the compression piston pin 240 through the compression piston bearing 280 .

[0054] The compression piston bearing 280 may be a roller bearing or a needle bearing.

[0055] In a possible implementation, the compression piston bearing 280 is a ball bearing. Roller bearings are simple to assemble and low in cost, and can effectively reduce the cost of the entire machine.

[0056] In some embodiments of the present application, see Figure 2 and Figure 8 The compression assembly includes a compression stabilizing spring pin 250 and a compression stabilizing spring 260. The compression stabilizing spring pin 250 is connected to the compression connecting rod. The compression stabilizing spring 260 is sleeved on the compression connecting rod, and the compression stabilizing spring 260 is located between the compression stabilizing spring pin 250 and the compression piston bearing 280. Among them, the compression stabilizing spring 260 is in a compressed state. Specifically, the compression stabilizing spring 260 cooperates with the compression piston bearing 280 to effectively reduce the matching clearance of the compression piston bearing 280, and can optimize the noise and vibration control of the whole machine. At the same time, the compression stabilizing spring 260 can effectively stabilize the operating state of the compression piston 220, reduce the friction between the compression piston 220 and the compression cylinder body, and increase the life of the friction pair. In other words, this embodiment can effectively increase the life of the refrigerator.

[0057] In the above embodiments, the compression piston bearing 280 may be a needle bearing, a ball bearing or other types of bearings.

[0058] In this embodiment, the compression piston bearing 280 is a needle bearing. The solution of using the needle bearing in combination with the compression stabilizing spring 260 has the characteristics of high reliability and high cost.

[0059] In some embodiments of the present application, see Figure 1 , Figure 2 and Figure 6 As shown, the expansion assembly includes a connecting piece 320, an expansion bearing pin 340 and an expansion assembly connecting pin 360. One end of the connecting piece 320 is rotatably connected to the expansion piston 310 through the expansion bearing pin 340, and the other end of the connecting piece 320 is rotatably connected to the first connecting end 211 through the expansion assembly connecting pin 360.

[0060] Further, see Figure 7 The expansion assembly includes an expansion piston connecting bearing 350, and the expansion piston connecting bearing 350 is sleeved on the expansion assembly connecting pin 360, wherein the first connecting portion 2111 has a mounting cavity for mounting the expansion piston connecting bearing 350. The connecting member 320 is connected to the expansion assembly connecting pin 360, thereby being rotatably connected to the first connecting portion 2111.

[0061] Further, see Figure 2 and Fig. 9 The outer circumference of the expansion bearing pin 340 is also sleeved with an expansion piston connecting bearing 350, and one end of the connecting member 320 is rotatably connected to the expansion bearing pin 340 through the expansion piston connecting bearing 350.

[0062] The expansion piston connecting bearing 350 may be of various bearing types. For example, the expansion piston connecting bearing 350 may be a needle bearing, a ball bearing or other types of bearings, which are not limited here.

[0063] For example, in one possible implementation, see Figure 2 and Fig.10 , the expansion piston connecting bearing 350 is a needle bearing 351 .

[0064] For example, in another possible implementation, see Figure 2 and Fig.11 The expansion piston connecting bearing 350 is a ball bearing 352 .

[0065] In some embodiments of the present application, see Figure 6The expansion assembly includes an expansion stabilizing spring 370, which is disposed between the expansion bearing pin 340 and the expansion assembly connecting pin 360. The expansion stabilizing spring 370 is in a compressed state. The expansion stabilizing spring 370 can apply a preload force to the expansion piston connecting bearing 350 installed on the expansion bearing pin 340 and / or the expansion assembly connecting pin 360, and the preload force can reduce the active clearance of the expansion piston connecting bearing 350, which can effectively reduce the noise and vibration generated during operation.

[0066] In the above embodiment, a compression spring is used as the expansion stabilizing spring 370 in the expansion assembly, which is different from some solutions in which a tension spring is used as the expansion stabilizing spring 370 or a solution in which the expansion stabilizing spring 370 is not used.

[0067] In some embodiments of the present application, see Figure 2 As shown, the expansion assembly includes a regenerator shell 330, and the regenerator shell 330 is rigidly connected to the expansion piston 310. The regenerator shell 330 is rigidly connected to the expansion piston 310, which can effectively avoid contact and wear between the regenerator shell 330 and the inner wall of the cold finger, and has higher reliability.

[0068] In other embodiments of the present application, see Figure 6 The regenerator shell 330 is connected to the expansion piston 310 via the flexible joint 380, so that the regenerator shell 330 can swing compared to the expansion piston 310. The flexible joint 380 has a better vibration control level.

[0069] It is worth understanding that in practical applications, the connection method between the regenerator shell 330 and the expansion piston 310 can be selected according to actual needs.

[0070] In some embodiments of the present application, see Figure 1 , Figures 2 to 4 The driving structure 120 includes a stator 122 and a rotor 121. The rotor 121 is connected to the central shaft 111, and an air gap is formed between the rotor 121 and the stator 122. The magnetic rotor 121 is installed on the central shaft 111 of the crankshaft 110, and drives the crankshaft 110 to rotate in a certain manner by cooperating with the stator 122. The stator 122 and the magnetic rotor 121 in the driving assembly together constitute a complete motor, which serves as a power source for the crankshaft 110 to drive the crankshaft 110 to operate.

[0071] In some embodiments of the present application, see Figure 1 , Figure 2 and Figure 5The drive assembly further includes a crankshaft balancing block 130, which is mounted on the central shaft 111. Since the eccentric motion has an unbalanced force, in order to balance the vibration caused by the eccentric force, a crankshaft balancing block 130 is also arranged on the central shaft 111 of the crankshaft 110. The precisely calculated crankshaft balancing block 130 can significantly reduce the vibration and noise output of the refrigerator.

[0072] Further, see Figure 3 and Figure 4 The driving structure 120 also includes a housing 123 and a control circuit 124. The control circuit 124 is installed in the housing 123 and is used to realize functions such as starting, accelerating, pausing, standing by, temperature control, timing, counting, fault diagnosis, etc.

[0073] In this embodiment, compared with the silicon steel sheet used in the stator core of the conventional motor, the 1J22 with stronger magnetic properties is used as the core material. Compared with the conventional silicon steel sheet, the 1J22 material has lower excitation current and better magnetic properties, that is, lower power consumption is required under the condition of generating the same torque, and thus has lower heat generation, so that the whole machine has lower heat generation and higher reliability.

[0074] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0075] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0076] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0077] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

Claims

1. A Stirling refrigerator, characterized in that: include: A driving assembly, comprising a crankshaft and a driving structure, wherein the crankshaft comprises a central shaft and an eccentric shaft connected to each other, and the driving structure is used to drive the central shaft to rotate; A compression assembly, comprising a compression connecting rod, a compression piston and a plurality of first bearings, wherein the plurality of first bearings are arranged at intervals along the axial direction of the eccentric shaft, the compression connecting rod comprises a first connecting end and a second connecting end, the first connecting end has a receiving cavity, the receiving cavity cooperates with the outer periphery of each of the first bearings, the second connecting end is rotatably connected to the compression piston, wherein the first connecting end comprises a first connecting portion; The expansion assembly includes an expansion piston connected to the first connection portion.

2. The Stirling refrigerator according to claim 1, characterized in that: A bearing isolation ring is arranged between two adjacent first bearings.

3. The Stirling refrigerator according to claim 1 or 2, characterized in that: The first bearings include two.

4. The Stirling refrigerator according to claim 1, characterized in that: The compression assembly includes a compression piston pin and a compression piston bearing sleeved on the compression piston pin, and the second connecting end is connected to the compression piston pin through the compression piston bearing.

5. The Stirling refrigerator according to claim 4, characterized in that: The compression assembly includes a compression stabilizing spring pin and a compression stabilizing spring, wherein the compression stabilizing spring pin is connected to the compression connecting rod, the compression stabilizing spring is sleeved on the compression connecting rod, and the compression stabilizing spring is located between the compression stabilizing spring pin and the compression piston bearing, wherein the compression stabilizing spring is in a compressed state.

6. The Stirling refrigerator according to claim 1, characterized in that: The expansion assembly includes a connecting piece, an expansion bearing pin and an expansion assembly connecting pin. One end of the connecting piece is rotationally connected to the expansion piston through the expansion bearing pin, and the other end of the connecting piece is rotationally connected to the first connecting end through the expansion assembly connecting pin.

7. The Stirling refrigerator according to claim 6, characterized in that: The expansion assembly includes an expansion stabilizing spring, and the expansion stabilizing spring is arranged between the expansion bearing pin and the expansion assembly connecting pin.

8. The Stirling refrigerator according to claim 1, characterized in that: The expansion assembly comprises a regenerator shell, which is rigidly connected to the expansion piston; or, the regenerator shell is connected to the expansion piston via a flexible joint.

9. The Stirling refrigerator according to claim 1, characterized in that: The driving structure includes a stator and a rotor. The rotor is connected to the central shaft, and an air gap is formed between the rotor and the stator.

10. The Stirling refrigerator according to claim 1, characterized in that: The drive assembly also includes a crankshaft balance weight mounted on the center shaft.

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