High-power stirling refrigerator device

Abstract

Provided is a high-power Stirling refrigerator device, comprising two or more power piston structures and a displacer structure. The two or more power piston structures are in fluid communication with the displacer structure. The power piston structures each comprise a power piston. The displacer structure comprises a first piston (1), a displacement plate spring (3), and a second piston (2) arranged in sequence in an axial direction thereof. In the refrigeration process, two or more power pistons of the two or more power piston structures and the first piston (1) form a compression chamber, high-pressure gas flows back and forth in the compression chamber and an expansion chamber at the end of the second piston (2) distant from the displacement plate spring (3), and the gas in the expansion chamber performs positive work on the displacer structure, thus achieving refrigeration. With the arrangement of the displacer structure and the power piston structures, the space of the compression chamber is increased and the motion damping of the displacer in the refrigeration process is reduced.

Description

A high-power Stirling refrigerator device Technical Field

[0001] The present application relates to the field of refrigeration and cryogenic technology, and in particular to a high-power Stirling refrigerator device. Background Art

[0002] With the rapid development of molecular biology and life sciences, artificially created cryogenic environments are playing a vital role. Cryogenic storage technology has a wide range of applications in medicine and biology, including the preservation of blood and blood products, specialty pharmaceuticals, vaccines, human organs, and biological specimens. For cryogenic storage of biological specimens, generally speaking, the lower the temperature, the longer the sample's stable storage time. Different temperatures have different protective effects on biological specimens. -80°C is a commonly used storage temperature for biological specimens. At this temperature, cellular DNA is relatively stable. Most biomacromolecules, such as RNA, proteins, and lipids, also have a certain degree of stability at -80°C. Generally, biological specimens can be stored for several months at this temperature. -196°C is the temperature of liquid nitrogen, at which physiological and biochemical activities within biological specimens essentially cease, allowing them to be preserved for decades. The establishment of cryogenic cold storage and refrigerators within the -196°C to -80°C temperature range requires a suitable refrigeration method. Furthermore, existing refrigerators typically utilize a single power piston and a single ejector, resulting in relatively low cooling power and insufficient refrigeration capacity.

[0003] Since the free-piston Stirling refrigerator was first proposed, the structural design of the displacer has been crucial to determining the cooling effect and overall structure. The existing displacer structure primarily consists of a thin rod connected to the power piston near the compression chamber. The rod passes through the power piston and the linear motor, and the end of the rod is connected to a displacer spring fixed within the back-pressure chamber, forming a free piston. The disadvantage of this piston-through-rod structure is that the power piston and displacer are prone to mutual motion interference, increasing the damping of the displacer and resulting in a decrease in cooling effect. It also increases the design difficulty of the power piston, resulting in low stability and difficult installation.

[0004] Therefore, this application urgently needs to develop a high-power Stirling refrigerator device, which increases the space of the compression chamber by cleverly designing and arranging the displacer structure and the power piston structure, thereby achieving high-power refrigeration and significantly reducing the damping of the displacer movement during movement.

[0005] Summary of the Invention

[0006] The purpose of the present application is to provide a high-power Stirling refrigerator device, which increases the space of the compression chamber by cleverly designing and arranging the displacer structure and the power piston structure, thereby achieving high-power refrigeration and significantly reducing the damping of the displacer movement during the movement.

[0007] The first aspect of the present application provides a high-power Stirling refrigerator device, comprising: two or more power piston structures and a displacer structure, wherein:

[0008] the two or more power piston structures being in fluid communication with the displacer structure;

[0009] The power piston mechanism includes a power piston, and the displacer structure includes a first piston, a displacer plate spring, and a second piston sequentially arranged in an axial direction thereof, wherein the displacer plate spring is connected to the first piston and the second piston via a first fastener, so that when the first piston and the second piston reciprocate under the action of a gas pressure difference, the displacer plate spring radially supports the first piston and the second piston and provides axial stiffness to the first piston and the second piston;

[0010] During the refrigeration process, the two or more power pistons of the two or more power piston structures form a compression chamber with the first piston, and the high-pressure gas flows back and forth in the expansion chamber of the second piston at one end away from the discharge plate spring and the compression chamber. The gas in the expansion chamber performs positive work on the discharger structure, thereby providing refrigeration.

[0011] In another preferred embodiment, it further includes a linear motor assembly for driving the two or more power piston structures.

[0012] In another preferred embodiment, a cold finger assembly is further included, and the ejector structure is arranged in the cold finger assembly.

[0013] In another preferred example, the multiple power piston structures include a first power piston structure and a second power piston structure arranged opposite to each other in the axial direction, the first power piston structure and the second power piston structure have the same structure, and the ejector structure is arranged on the sides of the first power piston structure and the second power piston structure.

[0014] In another preferred example, the first power piston structure, the second power piston structure and the ejector structure are arranged in a T-shaped structure.

[0015] In another preferred example, along the axial direction, the first power piston structure includes a first power leaf spring, a first power bearing and a first power piston in sequence, wherein the first power leaf spring is connected to the first power bearing; the second power piston structure includes a second power piston, a second power bearing and a second power leaf spring in sequence.

[0016] In another preferred example, the upper end of the first power bearing is connected to the first power leaf spring, and the lower end of the first power bearing is connected to the first power piston.

[0017] In another preferred example, the upper end of the second power bearing is connected to the second power leaf spring, and the lower end of the second power bearing is connected to the second power piston.

[0018] In another preferred example, the displacer structure further includes a first displacer cylinder and a second displacer cylinder, and both ends of the displacer plate spring are fixedly connected to the first displacer cylinder or the second displacer cylinder, thereby realizing reciprocating motion of the first piston in the first displacer cylinder and reciprocating motion of the second piston in the second displacer cylinder.

[0019] In another preferred example, it also includes a power cylinder, which is arranged vertically with the first discharge cylinder and the second discharge cylinder, and the first power piston and the second power piston reciprocate in the power cylinder. The power cylinder is provided with a cylinder opening, so that the power piston structure is fluidically connected with the discharger structure.

[0020] In another preferred example, along the radial direction of the power cylinder, it also includes a power cylinder base and a cold finger base arranged on the radial outside of the power cylinder in sequence, the power cylinder base is provided with a cylinder base opening, and the cold finger base is provided with a cold finger base opening, so that the power piston structure is fluidically connected to the ejector structure.

[0021] In another preferred embodiment, it further includes a housing assembly, which includes an upper annular housing and a lower annular housing.

[0022] In another preferred embodiment, the first power piston structure and the second power piston structure are arranged in the upper annular shell and the lower annular shell.

[0023] In another preferred example, a cold finger assembly is further included, and the ejector structure is arranged in the cold finger assembly. The cold finger assembly includes a hot end heat dissipation copper ring, a heat regenerator shell, a cold end heat dissipation copper ring, and a cold finger end cover which are coaxially connected in sequence into one body; and a hot end heat dissipation filler, a heat regenerator, a cold end heat dissipation filler, a hot end limit steel ring, a heat regenerator limit ring, and a cold end limit steel ring which are arranged in sequence along the axial direction, wherein the hot end heat dissipation copper ring is fixedly connected to the upper annular shell and the lower annular shell.

[0024] The hot end limiting steel ring, the regenerator limiting ring, and the cold end limiting steel ring are used to fix the hot end heat dissipation filler, the regenerator, and the cold end heat dissipation filler respectively.

[0025] In another preferred embodiment, the displacer structure and the power piston structure constitute the cylinder assembly and the piston assembly of the refrigerator device.

[0026] In another preferred example, the cylinder assembly includes a first discharge cylinder, a second discharge cylinder, a power cylinder and a power cylinder base. The power cylinder and the power cylinder base are coaxially arranged with the first discharge cylinder and the second discharge cylinder, and the first discharge cylinder is coaxially inserted into the second discharge cylinder; the two ends of the discharge plate spring are fixedly connected to the first discharge cylinder or the second discharge cylinder, so as to realize the reciprocating motion of the first piston in the first discharge cylinder, the reciprocating motion of the second piston in the second discharge cylinder, and the sliding of the power piston in the power cylinder.

[0027] In another preferred example, the discharge plate spring is located between the first piston and the second piston.

[0028] In another preferred embodiment, the discharge leaf spring is composed of a double discharge leaf spring.

[0029] In another preferred example, the central axes of the first piston and the second piston are on the same straight line.

[0030] In another preferred embodiment, the central axes of the first piston and the second piston pass through the center point of the discharge leaf spring.

[0031] In another preferred example, the discharge plate spring is fixedly connected to the first piston and the second piston via a first fastener.

[0032] In another preferred example, the first piston, the second piston, and the discharge plate spring are coaxially installed.

[0033] In another preferred example, the first piston includes a cylindrical structure with a protruding bottom surface, the second piston includes a cylindrical structure with a protruding bottom surface, the first piston includes a first protruding bottom surface protruding toward the discharge plate spring, and the second piston includes a second protruding bottom surface protruding toward the discharge plate spring.

[0034] In another preferred example, the ejector structure further includes a first fastener, the first protruding bottom surface is provided with a first protruding portion, the second protruding bottom surface is provided with a second protruding portion, the first fastener passes through the ejection plate spring and is connected to the first protruding portion and the second protruding portion, thereby fixing the ejection plate spring to the first piston and the second piston.

[0035] In another preferred embodiment, the first protrusion is located at the center of the first protruding bottom surface, and the first protrusion is a cylindrical structure extending toward the discharge plate spring.

[0036] In another preferred embodiment, the second protrusion is located at the center of the second protrusion bottom surface, and the second protrusion is a cylindrical structure extending toward the discharge plate spring.

[0037] In another preferred example, the first protrusion is a cylindrical structure with an internal thread, and the second protrusion is a cylindrical structure with an internal thread. The internal thread cooperates with the external thread of the stud to complete the connection. Preferably, an appropriate amount of thread glue is applied when the first protrusion and the second protrusion are threadedly connected to the stud.

[0038] In another preferred example, when the discharge leaf spring is connected to the first protrusion and the second protrusion by the first fastener, the end face of the first protrusion is in contact with one surface of the discharge leaf spring, and the end face of the second protrusion is in contact with the other surface of the discharge leaf spring.

[0039] In another preferred example, the maximum axial distance between the first protruding bottom surface of the first piston and the discharge plate spring should be greater than the maximum amplitude of the discharger structure, and the maximum axial distance between the second protruding bottom surface of the second piston and the discharge plate spring should also be greater than the maximum amplitude of the discharger structure.

[0040] In another preferred example, the displacer structure further includes a first displacer cylinder and a second displacer cylinder, and both ends of the displacer plate spring are fixedly connected to the first displacer cylinder or the second displacer cylinder, thereby realizing reciprocating motion of the first piston in the first displacer cylinder and reciprocating motion of the second piston in the second displacer cylinder.

[0041] In another preferred embodiment, the ends of both ends of the discharge leaf spring away from the center are fixedly connected to the end surface of the first discharge cylinder through second fasteners.

[0042] In another preferred example, the second exhaust cylinder includes a connecting section and a accommodating section. The connecting section is located outside the first exhaust cylinder in the radial direction of the cylinder, and a gap between the connecting section and the first exhaust cylinder is sealed.

[0043] In another preferred example, the first exhaust cylinder and the second exhaust cylinder are gap-sealed by a cylinder seal.

[0044] In another preferred embodiment, the interface between the connecting section of the second exhaust cylinder and the first exhaust cylinder is coated with glue, thereby fixing the second exhaust cylinder and the first exhaust cylinder.

[0045] In another preferred example, the first exhaust cylinder is inserted into the connecting section of the second exhaust cylinder.

[0046] In another preferred embodiment, a plurality of grooves are provided on the inner wall of the accommodating section to reduce the amount of air cross-talk between the compression chamber and the expansion chamber through the gap, which has a positive effect on the sealing effect.

[0047] In another preferred embodiment, the positional relationship between the first piston, the second piston and the discharge plate spring must satisfy the following formula:

[0048] Wherein, m1 is the mass of the first piston, m2 is the mass of the second piston, L1 is the axial distance between the center point of the first piston and the center point of the discharge leaf spring along the axial direction of the first piston, L2 is the axial distance between the center point of the second piston and the center point of the discharge leaf spring along the axial direction of the second piston, g is the acceleration due to gravity, k is the radial stiffness of the discharge leaf spring, and δ is the air gap height between the outer wall surface of the first piston and the inner wall surface of the first discharge cylinder.

[0049] In another preferred example, the first power piston and / or the second power piston is designed as a hollow structure, the first power piston includes a first power piston housing and a first power piston end cover, and the second power piston includes a second power piston housing and a second power piston end cover.

[0050] The first piston is designed as a hollow structure, comprising a first piston outer shell and a first piston top cover, the first piston outer shell and the first piston top cover being sealed by a first piston seal, and the first piston outer shell is a cylindrical structure with a convex bottom surface;

[0051] The second piston is designed as a hollow structure. The second piston includes a second piston outer shell and a second piston top cover. The second piston outer shell and the second piston top cover are fixedly connected and sealed by threads. The second piston outer shell is a cylindrical structure with a protruding bottom surface.

[0052] In another preferred example, the first piston outer shell and the first piston top cover are fixed by a first piston fastener.

[0053] In another preferred embodiment, the first piston outer shell is a cylindrical structure with a bottom surface.

[0054] In another preferred example, the second piston outer shell is a cylindrical structure with a bottom surface.

[0055] In another preferred example, the first piston outer shell and the second piston outer shell are close to the discharge leaf spring and are arranged opposite to each other.

[0056] In another preferred embodiment, the first piston is made of aluminum alloy, and the second piston is made of engineering plastic.

[0057] In another preferred embodiment, the first exhaust cylinder is made of aluminum alloy, and the second piston is made of engineering plastic.

[0058] In another preferred embodiment, it further includes a first linear motor assembly for driving the first power piston and a second linear motor assembly for driving the second power piston.

[0059] In another preferred example, the first power leaf spring is arranged above the first linear motor assembly, and the second power leaf spring is arranged below the second linear motor assembly.

[0060] In another preferred example, the first linear motor assembly is located above the power cylinder base, and the first linear motor assembly includes a first outer magnetic yoke, a first permanent magnet mover, a first inner magnetic yoke, and a first coil.

[0061] In another preferred example, the second linear motor assembly is located below the power cylinder base, and the second linear motor assembly includes a second outer magnetic yoke, a second permanent magnet mover, a second inner magnetic yoke, and a second coil.

[0062] In another preferred example, the first permanent magnet mover includes a first permanent magnet, a first permanent magnet lower support ring, a first permanent magnet upper support ring, and a first transmission connection plate.

[0063] In another preferred example, the second permanent magnet mover includes a second permanent magnet, a second permanent magnet lower support ring, a second permanent magnet upper support ring, and a second transmission connecting plate.

[0064] In another preferred example, a first outer magnetic yoke upper support ring is provided at the upper end of the first outer magnetic yoke, and a first outer magnetic yoke lower support ring is provided at the lower end. The first outer magnetic yoke upper support ring, the first outer magnetic yoke, and the first outer magnetic yoke lower support ring are axially stacked and fixed above the cold finger base.

[0065] In another preferred example, a second outer magnetic yoke upper support ring is provided at the upper end of the second outer magnetic yoke, and a second outer magnetic yoke lower support ring is provided at the lower end. The second outer magnetic yoke upper support ring, the second outer magnetic yoke, and the second outer magnetic yoke lower support ring are axially stacked in sequence under the cold finger base.

[0066] In another preferred example, the first permanent magnet mover is fixed together with the first power bearing by a first fastening nut, the first power leaf spring is arranged above the support ring on the first outer magnetic yoke, and the first power leaf spring and the support ring on the first outer magnetic yoke are fastened together by a first screw, and the first inner magnetic yoke is fixed on the base of the power cylinder.

[0067] In another preferred example, the second permanent magnet mover and the second power bearing are fixed together by a second fastening nut, the second power leaf spring is arranged below the lower support ring of the second outer magnetic yoke, and the second power leaf spring and the lower support ring of the second outer magnetic yoke are fastened together by a second screw, and the second inner magnetic yoke is fixed on the base of the power cylinder.

[0068] In another preferred example, the lower end surface of the upper annular shell and the upper end surface of the lower annular shell are fixedly connected to the cold finger base.

[0069] In another preferred embodiment, the hot end heat dissipation copper ring, the cold finger base and the upper annular shell are fixedly connected by welding.

[0070] In another preferred example, the upper annular shell is an annular shell including an upper top cover, the lower annular shell is an annular shell including a lower top cover, and the shell assembly also includes upper wiring terminals and lower wiring terminals, the upper wiring terminals are located on the upper top cover, the lower wiring terminals are located on the lower top cover, and the first wiring terminals and / or the second wiring terminals are used to connect the leads of the first coil and / or the second coil.

[0071] It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features described in detail below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be listed here one by one. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. It should be understood that the drawings described below are merely some implementation examples of the present invention, and those skilled in the art can also derive other implementation examples based on these drawings without inventive effort.

[0073] FIG1 is a schematic diagram of a high-power refrigerator device according to an embodiment of the present application;

[0074] FIG2 is a schematic diagram of the structure of an ejector of a high-power refrigerator device according to an embodiment of the present application;

[0075] FIG3 is a schematic cross-sectional view of the ejector structure of a high-power refrigerator device according to an embodiment of the present application;

[0076] FIG4 is a schematic structural diagram of an ejector plate spring of an ejector structure according to an embodiment of the present application.

[0077] In the accompanying drawings, the following are marked:

[0078] 1-first piston; 10-first protruding bottom surface; 101-first protruding portion; 11-first piston outer shell; 12-first piston top cover; 13-first piston seal; 14-first piston fastener;

[0079] 2-second piston; 20-second protruding bottom surface; 201-second protruding portion; 21-second piston outer shell; 22-second piston top cover;

[0080] 3-discharge leaf spring; 31-first fastener; 32-second fastener;

[0081] 41 - first exhaust cylinder; 42 - second exhaust cylinder; 43 - cylinder seal; 421 - connection section; 422 - accommodation section; 4221 - groove;

[0082] 50 - power cylinder; 51 - first power leaf spring; 52 - first power bearing; 53 - first power piston housing; 54 - first power piston end cover; 55 - first fastening plate;

[0083] 60 - power cylinder base; 61 - second power leaf spring; 62 - second power bearing; 63 - second power piston housing; 64 - second power piston end cover;

[0084] 71-cold finger base; 72-hot end heat dissipation copper ring; 73-regenerator housing; 74-cold end heat dissipation copper ring; 75-cold finger end cover; 76-hot end heat dissipation filler; 77-regenerator; 78-cold end heat dissipation filler; 79-hot end limit steel ring; 710-regenerator limit ring; 711-cold end limit steel ring;

[0085] 81 - first outer magnetic yoke; 811 - first outer magnetic yoke upper support ring; 812 - first outer magnetic yoke lower support ring; 82 - first inner magnetic yoke; 83 - first coil; 84 - first permanent magnet; 85 - first permanent magnet lower support ring; 86 - first permanent magnet upper support ring; 87 - first transmission connecting plate; 88 - first fastening nut; 89 - first screw;

[0086] 91 - second outer magnetic yoke; 911 - upper support ring of second outer magnetic yoke; 912 - lower support ring of second outer magnetic yoke; 92 - second inner magnetic yoke; 93 - second coil; 94 - second permanent magnet; 95 - lower support ring of second permanent magnet; 96 - upper support ring of second permanent magnet; 97 - second transmission connection plate (the directional terms "upper" and "lower" of the second linear motor assembly are to correspond to the corresponding components in the first linear motor assembly and do not indicate specific directions);

[0087] 1001-upper annular housing; 1002-lower annular housing; 1003-upper wiring terminal; 1004-lower wiring terminal;

[0088] L1-Axial distance between the center point of the first piston and the center point of the discharge leaf spring in the axial direction of the first piston

[0089] L2-Axial distance between the center point of the second piston and the center point of the discharge leaf spring in the axial direction of the second piston

[0090] δ - air gap height between the outer wall of the first piston and the inner wall of the first exhaust cylinder DETAILED DESCRIPTION

[0091] Through extensive and in-depth research, the inventors have developed a high-power, integrated free-piston Stirling refrigerator. This device features multiple synchronously operating power pistons and a single displacer piston, increasing the compression chamber space and achieving a cooling capacity of 1.0-1.5 kW. Furthermore, the displacer structure in this refrigerator eliminates the slender connecting rod structure of the displacer leaf spring known in the prior art. By employing a dual-cylinder, dual-piston, and displacer leaf spring configuration, heat leakage from the displacer's hot end to the cold end is reduced, eliminating direct interference and wear between the displacer and other refrigerator components, significantly reducing frictional damping, and simultaneously achieving airtightness, low axial heat conduction, and low mass, resulting in a superior cooling effect.

[0092] the term

[0093] As used herein, "ejector" and "ejector structure" are used interchangeably.

[0094] As used herein, "housing," "casing," and "housing body" are used interchangeably.

[0095] As used herein, “axial distance” refers to a distance along the axial direction of the first piston or the second piston.

[0096] As used herein, "hot end piston," "hot end discharge piston," and "first piston" refer to the same component;

[0097] As used herein, "cold end piston," "cold end discharge piston," and "second piston" refer to the same component;

[0098] As used herein, "first discharge cylinder" and "hot end cylinder" refer to the same component;

[0099] As used herein, "second-discharge cylinder" and "cold-end cylinder" refer to the same component;

[0100] It should be noted that the "high-power Stirling refrigerator device" involved in this application also refers to the "high-power free-piston Stirling refrigerator device" or the "high-power integral free-piston Stirling refrigerator device";

[0101] It should be noted that in this patent application, relational terms such as first and second, etc., are used solely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, the terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. Without further limitation, an element specified by the phrase "comprising a" does not preclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element. In this patent application, reference to performing an action in accordance with an element means performing the action in accordance with at least that element, including two situations: performing the action in accordance with that element alone, and performing the action in accordance with that element and other elements. Expressions such as "plurality," "multiple times," and "many" include "two," "twice," "two kinds," and "more than two," "more than two times," and "more than two kinds."

[0102] In the present invention, all directional indications (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0103] Main advantages of the present invention

[0104] (a) The refrigerator device of the present application increases the space of the compression chamber by providing multiple synchronously operating power piston structures and a single displacer piston structure, and provides a cooling capacity of 1.0-1.5 kW in the temperature range of -196°C to -80°C;

[0105] (b) The refrigerator device of the present application has an ingenious structural arrangement, and the power piston structure and the displacer structure do not interfere with each other;

[0106] (c) The power piston structure and the displacer structure of the present application are cleverly arranged, with the displacer structure being placed on the side of the power piston structure. The displacer structure eliminates the slender connecting rod structure of the displacer plate spring known in the prior art, that is, the practice of using a displacer base placed inside the compression chamber and a displacer plate spring disposed inside the displacer is abandoned. At the same time, redundant parts other than the cylinder that may directly wear against the displacer are removed, so that the displacer structure significantly reduces friction damping during movement, ensures excellent airtightness between the displacer and the cylinder (small shuttle loss and pumping loss), simplifies the refrigerator structure, reduces installation difficulty, and ensures safe and reliable operation of the refrigerator.

[0107] (d) The displacer structure of the present application eliminates direct interference and wear between the displacer piston and other components of the refrigerator, thereby improving the refrigeration efficiency and stability of the refrigerator;

[0108] (e) The ejector structure of the present application solves the problem of excessive distance between the ejector leaf spring and the ejector piston in the prior art by arranging the ejector leaf spring between the first piston and the second piston, thereby making the coaxiality of the entire ejector easy to control, reducing the difficulty of installation, and improving stability.

[0109] In the following description, many technical details are provided to help readers better understand this application. However, those skilled in the art will understand that even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can be implemented.

[0110] High-power integral free-piston Stirling refrigerator device

[0111] The present application provides a high-power Stirling refrigerator device, comprising: two or more power piston structures and a displacer structure, wherein:

[0112] the two or more power piston structures being in fluid communication with the displacer structure;

[0113] The power piston mechanism includes a power piston, and the displacer structure includes a first piston 1, a displacer plate spring 3, and a second piston 2 arranged in sequence along the axial direction thereof. The displacer plate spring 3 is connected to the first piston 1 and the second piston 2 via a first fastener 31, so that when the first piston 1 and the second piston 2 reciprocate under the action of the gas pressure difference, the displacer plate spring 3 radially supports the first piston 1 and the second piston 2 and provides axial stiffness for the first piston 1 and the second piston 2;

[0114] During the refrigeration process, high-pressure gas flows back and forth in the expansion chamber of the second piston 2 at one end away from the discharge plate spring 3 and the compression chamber formed by the multiple power pistons and the first piston 1. The gas in the expansion chamber does positive work on the discharger structure, thereby providing refrigeration.

[0115] In one embodiment, the multiple power piston structures are identical, and the Stirling refrigerator device further includes a linear motor assembly for driving the power piston structures, and a cold finger assembly disposed outside the displacer structure. In one embodiment, the number of the power piston structures is two or four.

[0116] In this application, a case where there are two multiple power piston structures is given, referring to Figure 1, and the multiple power piston structures include a first power piston structure and a second power piston structure arranged opposite to each other in the axial direction, and the structures of the first power piston structure and the second power piston structure are the same, and the ejector structure (which will be explained in detail below) is arranged on the sides of the first power piston structure and the second power piston structure, that is, the first power piston structure, the second power piston structure and the ejector structure are arranged into a T-shaped structure.

[0117] Along the axial direction, the first power piston structure comprises, in order, a first power leaf spring 51, a first power bearing 52, and a first power piston, wherein the first power leaf spring 51 is connected to the first power bearing 52. The second power piston structure comprises, in order, a second power piston, a second power bearing 62, and a second power leaf spring 61. The first power piston and / or the second power piston are designed as hollow structures. The first power piston comprises a first power piston housing 53 and a first power piston end cap 54, while the second power piston comprises a second power piston housing 63 and a second power piston end cap 64. The upper end of the first power bearing 52 is connected to the first power leaf spring 51, while the lower end is connected to the first power piston. The upper end of the second power bearing 62 is connected to the second power leaf spring 61, while the lower end is connected to the second power piston. The first and second power pistons share the same power cylinder 50 and cylinder base 60. To ensure fluid communication between the power piston structure and the displacer structure, a cylinder opening is provided in the power cylinder 50, and a cylinder base opening is provided in the power cylinder base 60. In one embodiment, the power bearing and the power piston are made of a lightweight, high-strength aluminum alloy. The power cylinder base 60 is connected and fastened to the cold finger base 71 by screws.

[0118] 1 , the cooling device further includes a cold finger assembly, a first linear motor assembly for driving a first power piston, a second linear motor assembly for driving a second power piston, and a housing assembly.

[0119] The cold finger assembly consists of a cold finger end cap 75, a cold end heat sink copper ring 74, a regenerator housing 73, a hot end heat sink copper ring 72, a cold finger base 71, a cold end heat sink filler 78, a regenerator 77, a hot end heat sink filler 76, a cold end stopper steel ring 711, a regenerator stopper ring 710, and a hot end stopper steel ring 79. The hot end heat sink copper ring 72, the cold finger base 71, and the housing assembly are welded together. The cold finger end cap 75, the cold end heat sink copper ring 74, the regenerator housing 73, and the hot end heat sink copper ring 72 are coaxially mounted and joined together using vacuum brazing, with coaxiality controlled to within 0.005 mm. The hot-end heat dissipation filler 76 and the cold-end heat dissipation filler 78 are constructed of folded copper sheets and are hydraulically pressed into corresponding positions inside the cold fingers. The regenerator 77 is constructed of wound polymer film or stainless steel mesh filler. The hot-end heat dissipation filler 76, the regenerator 77, and the cold-end heat dissipation filler 78 are arranged between the second exhaust cylinder 42 and the hot-end heat dissipation copper ring 72, the regenerator housing 73, and the cold-end heat dissipation copper ring 74. The hot-end limiting steel ring 79, the regenerator limiting ring 710, and the cold-end limiting steel ring 711 are sequentially arranged along the axial direction. The cold-end limiting steel ring 711, the regenerator limiting ring 710, and the hot-end limiting steel ring 79 are sequentially pressed into corresponding positions to secure the hot-end and cold-end heat dissipation fillers 78, 76, and the regenerator 77. The hot-end heat dissipation copper ring 72 is welded to the upper annular housing 1001 of the housing assembly. In the radial direction, from the inside to the outside, the cooling components include the hot end limit steel ring 79, the regenerator limit ring 710, the cold end limit steel ring 711; the end heat dissipation filler 76, the regenerator 77, the cold end heat dissipation filler 78; and the hot end heat dissipation copper ring 72, the regenerator shell 73, and the cold end heat dissipation copper ring 74.

[0120] The first and second linear motor assemblies have identical structures and are axially opposed to each other. The first power leaf spring 51 is positioned above the first linear motor assembly, while the second power leaf spring 61 is positioned below the second linear motor assembly. The first or second power leaf spring 51, 61 is fixedly connected to the first or second dynamic bearing 52, 62, which is in turn integrally secured to the permanent magnet mover of the linear motor assembly.

[0121] The first linear motor assembly is located above the power cylinder base 60 and includes a first outer magnetic yoke 81, a first permanent magnet mover, a first inner magnetic yoke 82, and a first coil 83. The first permanent magnet mover includes a first permanent magnet 84, a first permanent magnet lower support ring 85, a first permanent magnet upper support ring 86, and a first transmission connection plate 87. The upper end of the first outer magnetic yoke 81 is provided with a first outer magnetic yoke upper support ring 811, and the lower end is provided with a first outer magnetic yoke lower support ring 812. The first outer magnetic yoke upper support ring, the first outer magnetic yoke, and the first outer magnetic yoke lower support ring 812 are axially stacked and fixed above the cold finger base 71 by stud nuts.

[0122] The second linear motor assembly is located below the power cylinder base 60 and includes a second outer magnetic yoke 91, a second permanent magnet mover, a second inner magnetic yoke 92, and a second coil 93. The second permanent magnet mover includes a second permanent magnet 94, a second permanent magnet lower support ring 95, a second permanent magnet upper support ring 96, and a second transmission connection plate 97. A second outer magnetic yoke upper support ring 911 is provided at the upper end of the second outer magnetic yoke 91, and a second outer magnetic yoke lower support ring 912 is provided at the lower end. The second outer magnetic yoke upper support ring 911, the second outer magnetic yoke 91, and the second outer magnetic yoke lower support ring 912 are stacked axially in sequence and fixed below the cold finger base 71 via stud nuts.

[0123] Taking the first linear motor and first power piston structure as an example, the first annular permanent magnet 84, the first permanent magnet lower support ring 85, the first permanent magnet upper support ring 86, and the first transmission connecting plate 87 are fastened together as a whole using stud nuts, and the entire radiation ring is magnetized. The first permanent magnet mover and the first power bearing 52 are fastened together as a whole using the first fastening nut 88. The first power leaf spring 51 is placed on the first outer magnetic yoke upper support ring 811 and fastened using the first screw 89. The first power leaf spring 51 has a circular hole in its center, and the tail end face of the first power bearing 52 has several internal threads. The end of the first power bearing 52 passes through the circular hole so that the lower bottom surface of the first power leaf spring 51 is in contact with the upper end face of the first fastening nut 88. The center of the first power leaf spring 51 is fastened to the first power bearing 52 using the first fastening plate 55 and screws. The first coil 83 is evenly and tightly wound around the hollow portion of the first inner yoke 82, forming a single unit. The first inner yoke 82 has an axial through-hole structure and is secured to the power cylinder base 60 via stud nuts. The center position deviation of the first permanent magnet 84, first outer yoke 81, and first inner yoke 82 is controlled within 0.1 mm.

[0124] The housing assembly includes an upper annular housing 1001, a lower annular housing 1002, an upper terminal block 1003, and a lower terminal block 1004. The lower end surface of the upper annular housing 1001 and the upper end surface of the lower annular housing 1002 are fixedly connected to the cold finger base 71 via argon arc welding. The first and second power piston structures are disposed within the upper and lower annular housings 1001, 1002. The hot end heat dissipation copper ring 72, the cold finger base 71, and the housing assembly are fixedly connected by welding.

[0125] The upper annular housing is an annular housing including an upper top cover, and the lower annular housing is an annular housing including a lower top cover. The housing assembly further includes the upper terminal block 1003 located on the upper top cover, and the lower terminal block 1004 located on the lower top cover. The first terminal block 1003 and / or the second terminal block 1004 are used to connect the leads of the first coil 83 and / or the second coil 93. Specifically, through holes are machined in the upper top cover of the upper annular housing 1001 or the lower top cover of the lower annular housing, and the terminal blocks 1003 or 1004 are welded to the housing 1001 or 1002 using energy storage welding. It is worth mentioning that all parts need to be dried in a drying oven at high temperature for a certain period of time before installation.

[0126] Discharger structure

[0127] The displacer is a key component of a free-piston Stirling refrigerator, regulating the phase of the working fluid flow within the refrigerator. A Stirling refrigerator consists of alternating oscillations between the compression piston and the displacer. High-pressure gas (helium) flows back and forth between the compression chamber, the hot-end radiator, the regenerator, the cold-end heat exchanger, and the expansion chamber. During a single refrigerator cycle, the gas in the expansion chamber performs positive work on the displacer, generating cooling capacity in the expansion chamber. Simultaneously, the displacer transfers the work done by the gas in the expansion chamber to the compression chamber, recovering acoustic work and improving the refrigerator's efficiency.

[0128] A free-piston Stirling refrigerator is a pneumatic refrigerator, meaning the movement of the displacer is driven by the pressure difference between the compression and expansion chambers, without any additional force driving its motion or phasing the internal gases. In a free-piston Stirling refrigerator, the displacer is directly connected to the displacer spring and is independent of the compression system, effectively acting as a "free" piston. The mass of the displacer, the stiffness of the displacer spring, and the damping during the displacer's motion play a key role in its phasing function.

[0129] The present application provides an ejector structure for a free-piston Stirling refrigerator. The structure adopts a dual-cylinder-dual ejector, which can reduce the damping of the ejector movement process, reduce the axial heat conduction from the hot end through the cylinder and the ejector to the cold end (for example, the second piston is made of engineering plastic with a low thermal conductivity coefficient), reduce the cross-flow between the compression chamber and the expansion chamber through the ejector, ensure the stable operation of the ejector, reduce the difficulty of installation, and improve the stability and cooling efficiency of the refrigerator.

[0130] 2 , the displacer structure includes a double cylinder (a first displacer cylinder 41 and a second displacer cylinder 42 ), a double piston displacer (a first piston 1 and a second piston 2 ), and a displacer plate spring 3 ; the displacer plate spring 3 is disposed between the first piston 1 and the second piston 2 ;

[0131] The first piston 1 (hot end discharge piston) and the second piston 2 (cold end discharge piston) are connected and fixed to the first piston 1, the second piston 2 and the discharge plate spring 3 by a first fastener 31, so that when the first piston 1 and the second piston 2 reciprocate under the action of the air pressure difference, the discharge plate spring 3 radially supports the first piston 1 and the second piston 2 and provides axial stiffness for the first piston 1 and the second piston 2.

[0132] In one embodiment, the cold and hot end discharge pistons are both designed to be hollow structures, and have cylindrical protrusions at the ends. The cylindrical protrusions are internally processed with internal threads, and the cold and hot end discharge pistons are installed and fastened on both sides of the discharge plate spring 3 through studs (first fasteners 31).

[0133] In one embodiment, the discharge leaf spring 3 comprises a double discharge leaf spring. In one embodiment, the central axes of the first piston 1 and the second piston 2 are collinear. In one embodiment, the central axes of the first piston 1 and the second piston 2 pass through the center point of the discharge leaf spring. In one embodiment, the discharge leaf spring 3 is fixedly connected to the first piston 1 and the second piston 2 via a first fastener 31. In one embodiment, the first piston 1, the second piston 2, and the discharge leaf spring 3 are coaxially mounted.

[0134] Discharge leaf spring

[0135] 3 and 4 , FIG. 3 shows a schematic cross-sectional view of the ejector structure of a free piston Stirling refrigerator; FIG. 4 shows a schematic structural view of the ejector plate spring of the ejector structure;

[0136] Both ends of the discharge leaf spring 3 are fixedly connected to the first discharge cylinder 41 or the second discharge cylinder 42 , thereby enabling the first piston 1 to reciprocate in the first discharge cylinder 41 and the second piston 2 to reciprocate in the second discharge cylinder 42 .

[0137] In one embodiment, the ends of the discharge leaf spring 9 (the ends away from the center) are secured to the end faces of the first discharge cylinder 41 (the ends facing the second discharge cylinder 42) via second fasteners 32. In one embodiment, the second fasteners 32 are second hexagon socket head cap screws. The coaxiality between the discharge leaf spring 3 and the first discharge cylinder 41 is controlled to within 0.005 mm. In one embodiment, the edges (ends) of the discharge leaf spring 3 away from the center are secured to the first discharge cylinder 41 via screws.

[0138] First exhaust cylinder and second exhaust cylinder

[0139] Referring to Figures 2-4 , the ejector structure of the present application adopts a dual-cylinder structure, which includes a first ejection cylinder 41 (hot-end cylinder) and a second ejection cylinder 42 (cold-end cylinder). Both ends of the ejection plate spring 3 are fixedly connected to the first ejection cylinder 41 or the second ejection cylinder 42, thereby achieving reciprocating motion of the first piston 1 in the first ejection cylinder 41 and reciprocating motion of the second piston 2 in the second ejection cylinder 42. The first ejection cylinder 41 and the second ejection cylinder 42 are arranged perpendicular to the power cylinder 50.

[0140] The second discharge cylinder 42 includes a connecting section 421 and a accommodating section 422. In the radial direction of the cylinder, the connecting section 421 is located on the outside of the first discharge cylinder 41. In other words, the first discharge cylinder 41 is inserted into the connecting section 421 of the second discharge cylinder 42, wherein the gap between the connecting section 421 and the first discharge cylinder 41 is sealed.

[0141] In one embodiment, a plurality of grooves 4221 are provided on the inner wall of the accommodating section 422 to reduce the amount of cross-flow between the compression chamber and the expansion chamber through the gap, which has a positive effect on the sealing effect.

[0142] In one embodiment, the first and second exhaust cylinders 41, 42 are gap-sealed by a cylinder seal 43. In one embodiment, the gap between the first and second exhaust cylinders 41, 42 is sealed by an O-ring and the interface between them is secured with glue. The coaxiality between the first and second exhaust cylinders 41, 42 is controlled within 0.005 mm. In one embodiment, the interface between the connecting section 421 of the second exhaust cylinder 42 and the first exhaust cylinder 41 is coated with glue to secure the second exhaust cylinder 42 to the first exhaust cylinder 41.

[0143] The first piston and the second piston

[0144] Referring to Figures 2 to 4, the first piston 1 includes a cylindrical structure with a protruding bottom surface, and the second piston 2 includes a cylindrical structure with a protruding bottom surface. The first piston 1 includes a first protruding bottom surface 10 protruding toward the discharge leaf spring 3, and the second piston 2 includes a second protruding bottom surface 20 protruding toward the discharge leaf spring 3. The first protruding bottom surface 10 and / or the second protruding bottom surface 20 are arranged to avoid the end or edge of the discharge leaf spring 3, away from the center, from colliding with the first piston 1 and / or the second piston 2 during the movement of the piston.

[0145] In one embodiment, the ejector structure further includes a first fastener 31. The first protruding bottom surface 10 is provided with a first protrusion 101, and the second protruding bottom surface 20 is provided with a second protrusion 201. The first fastener 31 passes through the ejector leaf spring 3 and connects with the first protrusion 101 and the second protrusion 201, thereby securing the ejector leaf spring 3 to the first and second pistons 1 and 2. In one embodiment, the first protrusion 101 is located at the center of the first protruding bottom surface 10 and is a cylindrical structure extending toward the ejector leaf spring 3. In one embodiment, the second protrusion 201 is located at the center of the second protruding bottom surface 20 and is a cylindrical structure extending toward the ejector leaf spring 3. In one embodiment, the first fastener 31 is a stud.

[0146] In one embodiment, the first protrusion 101 is a cylindrical structure with an internal thread, and the second protrusion 201 is a cylindrical structure with an internal thread. The internal thread cooperates with the external thread of the stud to complete the connection. Preferably, an appropriate amount of thread glue is applied when the first protrusion 101 and the second protrusion 201 are threadedly connected to the stud.

[0147] In one embodiment, when the discharge leaf spring 3 is connected to the first protrusion 101 and the second protrusion 201 by the first fastener 31, the end surface of the first protrusion 101 is in contact with one surface of the discharge leaf spring 3, and the end surface of the second protrusion 201 is in contact with the other surface of the discharge leaf spring.

[0148] In one embodiment, the axial distance between the first protruding bottom surface 10 of the first piston 1 and the discharge plate spring 3 should be greater than the maximum amplitude of the discharger structure, and the axial distance between the second protruding bottom surface 20 of the second piston 2 and the discharge plate spring 3 should also be greater than the maximum amplitude of the discharger structure.

[0149] To achieve good airtightness, the first piston 1 should maintain a small gap with the first discharge cylinder 3. However, the first piston may deviate from its center position under the action of gravity and even contact the wall of the cylinder. To prevent the displacer from contacting the wall and causing a significant increase in friction, it is assumed that the axial distance between the geometric center of the first piston and the center of the discharge leaf spring (or the axial distance between the center point of the first piston and the center point of the discharge leaf spring along the axial direction of the first piston) L1, the axial distance between the center point of the second piston (the second piston outer shell 21 and the second piston top cover 22) and the center of the discharge leaf spring along the axial direction of the second piston L2, the weight of the first piston 1 m1, the weight of the second piston 2 m2, the radial stiffness of the discharge leaf spring 3, and the air gap δ between the first piston and the cylinder should maintain a certain relationship.

[0150] The positional relationship among the first piston 1, the second piston 2 and the discharge plate spring 3 can satisfy the following formula:

[0151] Where m1 is the mass of the hot-end discharge piston, m2 is the mass of the cold-end discharge piston, L1 is the axial distance between the center of the hot-end discharge piston and the center of the discharge leaf spring, L2 is the axial distance between the center of the cold-end discharge piston and the center of the discharge leaf spring, g is the acceleration due to gravity, k is the radial stiffness of the discharge leaf spring 9, and δ is the air gap height between the hot-end discharge piston wall and the hot-end cylinder inner wall. See Figure 3, where L1, L2, and δ are schematically illustrated.

[0152] (a) First piston

[0153] In order to reduce the mass of the ejector and make it lighter, the first piston 1 adopts a hollow structure. The first piston 1 includes a first piston outer shell 11 and a first piston top cover 12. The first piston outer shell 11 and the first piston top cover 12 are sealed by a first piston seal 13. The first piston outer shell 11 and the first piston top cover 12 are connected and fixed by a first piston fastener 14. In one embodiment, the first piston seal 13 is an O-ring. In one embodiment, the first piston fastener 14 is a hexagon socket screw. Preferably, the first piston outer shell 11 is a cylindrical structure with a protruding bottom surface. In one embodiment, the first piston 1 includes a first protruding bottom surface 10 protruding toward the ejector plate spring 3. The first protruding bottom surface 10 is provided with a cylindrical protrusion 101 (i.e., a first protruding portion 101) facing the ejector plate spring 3, and the center of the protruding cylinder is processed with an internal thread.

[0154] In one embodiment, the first piston housing 11, the first piston top cover 12, the O-ring and several screws constitute the first piston assembly. The first piston housing 11 and the first piston top cover 12 are sealed by the O-ring to prevent the loss of compression work caused by the gas in the compression chamber entering and exiting the first piston assembly. The first piston housing 11 and the first piston top cover 12 are fastened by eight screws.

[0155] In one embodiment, to prevent direct collision between the first piston and the deformed discharge leaf spring during movement, the first piston housing has a slope on the side near the cold end (second piston) or the discharge leaf spring 3. The slope is determined by the maximum vibration amplitude of the discharger assembly. In other words, the first piston housing includes a first protruding bottom surface 10 facing the discharge leaf spring 3, thereby providing a sloped bottom surface of the first piston housing. The maximum axial distance between the first protruding bottom surface 10 of the first piston 1 and the discharge leaf spring 3 is greater than the maximum vibration amplitude of the discharger structure. Furthermore, the first piston housing (hot end piston housing) of the discharger has a cylindrical protrusion (first protrusion 101) on the side near the expansion chamber (or near the discharge leaf spring). The center of the protrusion is internally threaded to facilitate connection with the discharge leaf spring 3 and the second piston 2.

[0156] (b) Second piston

[0157] To reduce the mass of the displacer and make it lighter, the second piston 2 adopts a hollow structure. Preferably, to reduce internal empty volume and control mass, the second piston is filled with a rollable lightweight material. The second piston 2 comprises a second piston outer shell 21 and a second piston top cover 22, which are fixedly connected and sealed via internal and external threads. Preferably, the first piston outer shell 11 and the second piston outer shell 21 are arranged opposite each other near the displacer leaf spring 3. Preferably, the second piston outer shell is a cylindrical structure with a convex bottom surface.

[0158] Similarly, to prevent the second piston from colliding with the discharge leaf spring during movement, the second piston outer shell has a certain slope on the side close to the discharge leaf spring. The size of the slope is determined by the maximum amplitude of the discharger assembly. In other words, the second piston outer shell includes a second protruding bottom surface 20 facing the discharge leaf spring 3, thereby making the bottom surface of the second piston shell have a slope, and the maximum axial distance between the second protruding bottom surface 20 of the second piston 2 and the discharge leaf spring 3 should be greater than the maximum amplitude of the discharger structure. The second piston outer shell 21 has a boss (second protrusion 201) close to the discharge leaf spring, and the center of the boss has an internal threaded hole of a certain depth.

[0159] In one embodiment, a stud extends through the internal threads of the protrusion (first protrusion 101) or boss (second protrusion 201) of the first and second piston outer shells, connecting the discharge leaf spring to the first and second piston outer shells and securing them with glue applied to the screw surface. Specifically, the stud extends through the protrusion (first protrusion 101) on the bottom surface of the first protrusion, the discharge leaf spring 3, and the boss 201 (i.e., second protrusion 201) on the bottom surface of the second protrusion 20. The coaxiality of the first piston 1, second piston 2, and discharge leaf spring 3 is controlled within 0.005 mm.

[0160] Discharger structural components materials

[0161] The existing displacer structure consists of a single piston, which runs through the compression chamber at the hot end and the expansion chamber at the cold end. Displacer structures are generally made of aluminum alloy, stainless steel, or polymer (engineering plastic). Metal displacer structures have low thermal deformation, high strength, high machining accuracy, and high thermal conductivity. The gap between the cylinder and the displacer can be designed to be very small, resulting in good airtightness, low shuttle loss, and low pumping loss. However, the disadvantage is that the axial heat conduction from the compression chamber to the expansion chamber is large, and the mass of the displacer is also large. Polymer materials generally have low strength, low machining accuracy, large thermal deformation, and low thermal conductivity. Their advantages are low axial heat conduction from the compression chamber to the expansion chamber through the displacer body and low mass. Their disadvantage is that a certain gap must be maintained between the displacer and the cylinder to prevent direct friction between the displacer and the cylinder due to temperature changes, resulting in a significant increase in the displacer's damping.

[0162] The various problems caused by the use of a single material for the displacer structure (as mentioned above) are solved by minimizing the axial heat conduction loss as much as possible while ensuring the airtightness between the compression chamber and the expansion chamber (reducing shuttle loss and pumping loss) to improve the efficient cooling effect of the refrigerator.

[0163] Therefore, in order to reduce the transfer of heat from the hot end to the cold end of the refrigerator through the cylinder, and at the same time to maintain a small gap between the piston and the cylinder, in the technical solution of the present application, the cylinder structure and the displacer structure are both made of a mixture of two materials, wherein the first discharge cylinder is made of metal material, such as aluminum alloy, stainless steel, titanium alloy, etc., and the second discharge cylinder is made of a polymer (engineering plastic) with low thermal conductivity and high strength, and the first discharge cylinder and the second discharge cylinder are connected by an O-ring and glued together.

[0164] Preferably, the first piston 1 is made of aluminum alloy with high strength and low density, and the hot end discharge piston surface is evenly sprayed with a wear-resistant and lubricating coating such as Teflon. The second piston 2 is made of engineering plastic with low thermal conductivity, low temperature resistance, and low thermal expansion coefficient.

[0165] Preferably, the first exhaust cylinder 41 is made of an aluminum alloy material with high thermal conductivity and high strength, wherein the inner cylinder wall surface of the first exhaust cylinder 41 is polished and hard-oxidized.

[0166] The second air discharge cylinder 42 is made of engineering plastics with low thermal conductivity, high strength and low thermal expansion coefficient. The inner wall surface of the accommodating section 422 of the second air discharge cylinder 42 adopts a sealing structure with multiple grooves 4221 .

[0167] This application also provides an embodiment of the steps for installing the ejector structure:

[0168] (1) Place an O-ring of appropriate size on the boss of the first piston top cover, and fix the first piston top cover to the first piston outer shell with 8 screws.

[0169] (2) Fill the second piston outer shell with lightweight material evenly, and then fix the second piston top cover to the second piston thread.

[0170] (3) Insert a stud of appropriate size and length through the circular hole in the center of the discharge plate spring 3, and connect the first piston and the second piston through threads. The raised end surface of the second piston outer shell (i.e., the end surface of the first protrusion 101 of the first protruding bottom surface 10) and the raised end surface of the first piston outer shell (i.e., the end surface of the second protrusion 201 of the first protruding bottom surface 10) are flush with the two surfaces of the discharge plate spring, and an appropriate amount of thread glue is applied during the threaded connection. It should be noted that during the installation process, the coaxiality of the discharge plate spring, the first piston (the first piston outer shell 11 and the first piston top cover 12) and the second piston (the second piston outer shell 21 and the second piston top cover 22) should be maintained, and the coaxiality needs to be maintained within 0.005mm.

[0171] (4) The discharge plate spring is coaxially mounted on the end face of the first discharge cylinder by eight screws, and the coaxiality is required to be within 0.005 mm.

[0172] (5) Finally, the first exhaust cylinder 41 and the second exhaust cylinder 42 are sealed by an O-ring and a proper amount of anaerobic glue is filled in the gap between the two to ensure the fixation of the two. The coaxiality should be controlled within 0.005 mm during the installation process.

[0173] It is worth mentioning that all parts need to be dried in a drying oven at high temperature for a certain period of time before installation.

[0174] The specification of this application records a large number of technical features, which are distributed in various technical solutions. If all possible combinations of technical features of this application (i.e., technical solutions) are to be listed, the specification will be too lengthy. In order to avoid this problem, the various technical features disclosed in the above-mentioned invention content of this application, the various technical features disclosed in the various embodiments and examples below, and the various technical features disclosed in the accompanying drawings can be freely combined with each other to form various new technical solutions (these technical solutions are all deemed to have been recorded in this specification), unless such a combination of technical features is technically infeasible. For example, in one example, feature A+B+C is disclosed, and in another example, feature A+B+D+E is disclosed. Features C and D are equivalent technical means that play the same role. Technically, only one of them can be used, and it is impossible to use them at the same time. Feature E can be technically combined with feature C. Then, the solution of A+B+C+D should not be considered as having been recorded because it is technically infeasible, while the solution of A+B+C+E should be considered as having been recorded.

[0175] All documents mentioned in this application are considered to be included in their entirety in the disclosure of this application so that they can be used as a basis for modification when necessary. In addition, it should be understood that after reading the above disclosure of this application, those skilled in the art may make various changes or modifications to this application, and these equivalent forms also fall within the scope of protection claimed in this application.

Claims

1. A high-power Stirling refrigerator device, characterized in that: include: Two or more power piston structures and displacer structures, wherein: The two or more power piston structures are in fluid communication with the ejector structure; The power piston mechanism comprises a power piston, and the displacer structure comprises a first piston (1), a displacer plate spring (3), and a second piston (2) arranged in sequence along the axial direction thereof, wherein the displacer plate spring (3) is connected to the first piston (1) and the second piston (2) via a first fastener (31), so that when the first piston (1) and the second piston (2) reciprocate under the action of a gas pressure difference, the displacer plate spring (3) radially supports the first piston (1) and the second piston (2) and provides axial rigidity for the first piston (1) and the second piston (2); During the refrigeration process, high-pressure gas flows back and forth in the expansion chamber of the second piston (2) at one end away from the discharge plate spring (3) and the compression chamber formed by the multiple power pistons and the first piston (1), and the gas in the expansion chamber performs positive work on the discharger structure, thereby providing refrigeration.

2. The refrigerator device according to claim 1, characterized in that: Also included is a linear motor assembly for driving the two or more power piston structures.

3. The refrigerator device according to claim 2, characterized in that: Also included is a cold finger assembly, the ejector structure being disposed within the cold finger assembly.

4. The refrigerator device according to claim 1, characterized in that: The multiple power piston structures include a first power piston structure and a second power piston structure that are arranged opposite to each other in the axial direction, the first power piston structure and the second power piston structure have the same structure, and the ejector structure is arranged on the sides of the first power piston structure and the second power piston structure.

5. The refrigerator device according to claim 4, characterized in that: Along the axial direction, the first power piston structure comprises a first power leaf spring (51), a first power bearing (52) and a first power piston in sequence, wherein the first power leaf spring (51) is connected to the first power bearing (52); the second power piston structure comprises a second power piston, a second power bearing (62) and a second power leaf spring (61) in sequence.

6. The refrigerator device according to claim 5, characterized in that: The displacer structure further comprises a first displacer cylinder (41) and a second displacer cylinder (42), and both ends of the displacer plate spring (3) are fixedly connected to the first displacer cylinder (41) or the second displacer cylinder (42), so that the first piston (1) can reciprocate in the first displacer cylinder (41) and the second piston (2) can reciprocate in the second displacer cylinder (42).

7. The refrigerator device according to claim 6, characterized in that It also includes a power cylinder (50), which is vertically arranged with the first discharge cylinder (41) and the second discharge cylinder (42), and the first power piston and the second power piston reciprocate in the power cylinder (50). The power cylinder is provided with a cylinder opening, so that the power piston structure is fluidically connected with the discharger structure.

8. The refrigerator device according to claim 7, characterized in that: Along the radial direction of the power cylinder, it also includes a power cylinder base (60) and a cold finger base (71) arranged on the radial outer side of the power cylinder (50) in sequence, the power cylinder base (60) being provided with a cylinder base opening, and the cold finger base (71) being provided with a cold finger base opening.

9. The refrigerator device according to claim 1, characterized in that: The first piston (1) comprises a cylindrical structure with a protruding bottom surface, the second piston (2) comprises a cylindrical structure with a protruding bottom surface, the first piston (1) comprises a first protruding bottom surface (10) protruding toward the discharge plate spring (3), and the second piston (2) comprises a second protruding bottom surface (20) protruding toward the discharge plate spring (3).

10. The refrigerator device according to claim 9, characterized in that The ejector structure further comprises a first fastener (31); the first protruding bottom surface (10) is provided with a first protruding portion (101); the second protruding bottom surface (20) is provided with a second protruding portion (201); the first fastener (31) passes through the ejector leaf spring (3) and is connected to the first protruding portion (101) and the second protruding portion (201), thereby fixing the ejector leaf spring (3) to the first piston (1) and the second piston (2).

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