Miniature rotary integral Stirling refrigerator

Abstract

The miniature rotary integral Stirling cryocooler comprises a crankcase, a compression piston assembly, a pushing piston assembly and a motor component, and the motor component comprises a motor stator assembly, a rotor spring assembly and a rotor protection sleeve; the compression piston assembly, the pushing piston assembly and the rotor spring assembly are all arranged in the crankcase, the motor stator assembly is arranged above the crankcase, and the crankcase and the rotor protection sleeve are pressed and fixed through a threaded clamping ring. The compression piston assembly is connected with the pushing piston assembly through a connecting rod, the compression piston assembly is connected with the rotor spring assembly through a connecting rod, and the motor stator assembly and the rotor spring assembly are isolated through a rotor protection sleeve. According to the embodiment of the invention, the radial size of the crankcase can be reduced through a sealing and pressing structure which replaces screw pressing and fixing through threaded clamping ring pressing and fixing, so that the height of the refrigerator is reduced, the weight of the refrigerator is reduced, and the miniaturized design of the rotary integral Stirling refrigerator is realized.

Description

Technical Field

[0001] The present application belongs to the technical field of refrigerators, and in particular to a miniature rotary integral Stirling refrigerator. Background Art

[0002] Stirling refrigerators can provide a low-temperature environment for infrared detectors. As the operating temperature of infrared detectors increases, the cooling capacity required for infrared detectors decreases, which significantly reduces the size, volume, and weight of Stirling refrigerators configured for high-operating-temperature infrared detectors. However, existing rotating integral Stirling refrigerators for infrared detectors have defects such as large size and heavy weight. Summary of the invention

[0003] The embodiment of the present application provides a miniature rotating integral Stirling refrigerator, which is used to at least solve the problem of large size and heavy weight of the rotating integral Stirling refrigerator used in infrared detectors in the related art.

[0004] The embodiment of the present application provides a miniature rotary integral Stirling refrigerator, comprising: a crankcase, a compression piston assembly, a push piston assembly and a motor component, wherein the motor component comprises a motor stator assembly, a rotor spring assembly and a rotor protective sleeve;

[0005] The compression piston assembly, the push piston assembly and the rotor spring assembly are all arranged in the crankcase, the motor stator assembly is arranged above the crankcase, and the crankcase and the rotor protection sleeve are pressed and fixed by a threaded clamp ring;

[0006] The compression piston assembly is connected to the push piston assembly through a connecting rod, the compression piston assembly is connected to the rotor spring assembly through the connecting rod, and the motor stator assembly and the rotor spring assembly are isolated from each other through a rotor protective sleeve.

[0007] The miniature rotary integral Stirling refrigerator of the embodiment of the present application comprises a crankcase, a compression piston assembly, a push piston assembly and a motor component, wherein the motor component comprises a motor stator assembly, a rotor spring assembly and a rotor protection sleeve; the compression piston assembly, the push piston assembly and the rotor spring assembly are all arranged in the crankcase, and the motor stator assembly is arranged above the crankcase, and the crankcase and the rotor protection sleeve are clamped and fixed by a threaded clamp ring, forming a sealing clamping structure in which the threaded clamp ring is clamped and fixed instead of the screw clamping and fixed, which can reduce the radial size of the crankcase, thereby reducing the height of the refrigerator, reducing the weight of the refrigerator, meeting the requirements of a miniaturized Stirling refrigerator for a high operating temperature infrared detector, and providing reliable support for the miniaturization development of infrared thermal imaging systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0009] Figure 1 It is a cross-sectional view of a corresponding push piston assembly portion of a micro rotary integral Stirling refrigerator provided in an embodiment of the present application;

[0010] Figure 2 is a cross-sectional view of a corresponding compression piston assembly portion of a micro rotary integral Stirling refrigerator provided in an embodiment of the present application;

[0011] Figure 3 is a cross-sectional view of a groove portion of a crankcase of a miniature rotary integral Stirling refrigerator provided in an embodiment of the present application;

[0012] Figure 4 It is a cross-sectional view of the fourth deep groove ball bearing portion at the bottom of the crankcase of the miniature rotary integral Stirling refrigerator provided in an embodiment of the present application.

[0013] Reference numerals:

[0014] Crankcase 100, first groove 110, second groove 120,

[0015] Compression piston assembly 200, compression cylinder 210, compression piston 220, compression piston pad 230, pin 240, first deep groove ball bearing 250, second deep groove ball bearing 260,

[0016] Push piston assembly 300, cold storage device 310, push piston 320, push cylinder 330, crescent ring 340,

[0017] Rotor spring assembly 410, motor stator assembly 420, rotor protection sleeve 430, eccentric shaft 411, balance ring 412, motor rotor 413, spring 414, third deep groove ball bearing 415, motor stator 421, housing 422,

[0018] Connecting rod 500, threaded collar 600, cold finger 700, press end cover 800,

[0019] Fourth deep groove ball bearing 910 , retaining ring 920 , and shaft sleeve 930 . DETAILED DESCRIPTION

[0020] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0021] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0022] Infrared detectors generally need to work in a low-temperature environment, and their typical working temperature is 77K. With the great breakthroughs in the research of high-working-temperature infrared detection device technology, the working temperature of infrared detectors has been greatly improved, and their typical working temperature has been increased from 77K to 110K~250K. High-working-temperature infrared detector components have become an important development direction of the third-generation infrared detector technology.

[0023] Stirling refrigerators can provide the required low temperature environment for infrared detectors to ensure good performance of infrared detectors. As the operating temperature of infrared detectors increases, the cooling capacity demand of infrared detectors decreases, which significantly reduces the size, volume and weight of Stirling refrigerators configured for high operating temperature infrared detectors.

[0024] The existing rotating integral Stirling refrigerator for infrared detectors has defects such as large size and heavy weight, and the mechanical reliability of the refrigerator needs to be further improved. Therefore, it is very necessary to develop a miniaturized and highly reliable rotating integral Stirling refrigerator for high operating temperature infrared detectors.

[0025] At present, the improvement measures adopted in the related technology for the rotating integral Stirling refrigerator include: optimizing the compression connecting rod, and the integrated structural design of the expansion cylinder, the cold finger cylinder and the base. However, it does not involve the design of the sealing and pressing structure, the base structure, etc., and cannot better meet the requirements of the miniaturized Stirling refrigerator for high-operating-temperature infrared detectors.

[0026] In order to solve the problems of the related art, the embodiment of the present application provides a micro-rotary integral Stirling refrigerator. The micro-rotary integral Stirling refrigerator provided by the embodiment of the present application is described in detail below through specific embodiments and application scenarios in conjunction with the accompanying drawings.

[0027] It should be noted that the micro-rotating integral Stirling refrigerator of this embodiment can be applied to high operating temperature infrared detectors, such as but not limited to a certain medium wave 640×512 infrared detector assembly.

[0028] In this embodiment, the micro rotary integral Stirling refrigerator can achieve the following performance indicators: cooling capacity ≥0.65W@23℃@140K; cooling time ≤3min@150J@23℃@140K (typical value 2.5min); input power ≤15W@23℃@140K (typical value 12W); steady-state power ≤5W@23℃@140K (typical value 3.6W); volume ≤60mm×39mm×57mm; weight ≤185g.

[0029] refer to Figure 1 , is a cross-sectional view of a corresponding push piston assembly portion of a micro-rotary integral Stirling refrigerator according to an embodiment of the present application. Figure 1 As shown, the micro rotary integral Stirling refrigerator includes: a crankcase 100, a compression piston assembly 200, a push piston assembly 300 and a motor component, wherein the motor component includes a rotor spring assembly 410, a motor stator assembly 420 and a rotor protection sleeve 430.

[0030] Specifically, the compression piston assembly 200, the push piston assembly 300 and the rotor spring assembly 410 are all arranged in the crankcase 100, and the lower end of the rotor spring assembly 410 extends into the bottom of the crankcase 100, and the motor stator assembly 420 is arranged above the crankcase 100; the compression piston assembly 200 is connected to the push piston assembly 300 through the connecting rod 500, and the compression piston assembly 200 is connected to the rotor spring assembly 410 through the connecting rod 500, and the motor stator assembly 420 and the rotor spring assembly 410 are isolated from each other by the rotor protection cover 430.

[0031] In some embodiments, the crankcase 100 and the rotor protection cover 430 are compressed and fixed by a threaded collar 600 to form a sealing compression structure. Compared with the previous structure of compressing and fixing by screws, since the relevant technology needs to provide space for the screw tightening process, the threaded collar 600 used in this embodiment can greatly reduce the radial size of the crankcase 100, thereby reducing the height of the refrigerator, that is, reducing the overall size and weight of the refrigerator.

[0032] Optionally, the external threads of the threaded collar 600 are threadedly engaged with the internal threads on the crankcase 100 , so that the threaded collar 600 replaces the screws used for compression and fixing in the previous structure.

[0033] Further, Figure 2 FIG. 1 is a cross-sectional view of a corresponding compression piston assembly portion of a micro-rotary integral Stirling refrigerator according to an embodiment of the present application. Figure 1 and Figure 2 As shown, the micro rotary integral Stirling refrigerator of this embodiment further includes a cold finger 700 and a compressor end cover 800. Specifically, the crankcase 100 and the cold finger 700 are fixed by screws, and the crankcase 100 and the compressor end cover 800 are fixed by screws.

[0034] In some optional embodiments, such as Figure 1 As shown, the push piston assembly 300 includes a cold storage device 310, a push piston 320, a push cylinder 330, a crescent ring 340 and two pins. Specifically, a gap seal is formed between the push piston 320 and the push cylinder 330, one side of the crescent ring 340 is rotatably connected to the connecting rod 500 through a pin, and the other side of the crescent ring 340 is rotatably connected to the push piston 320 through another pin, and the push piston 320 and the cold storage device 310 are connected by threads, and the cold storage device 310 reciprocates in the cold finger 700.

[0035] As an optional embodiment, Figure 3 FIG. 1 shows a cross-sectional view of the groove portion of the crankcase 100 of the micro-rotary integral Stirling refrigerator of this embodiment. Figure 3 As shown, the inner wall surface of the crankcase 100 is provided with at least two grooves (i.e. Figure 3 The first groove 110 and the second groove 120 are provided in the push piston assembly 300. It should be noted that the positions of the at least two grooves are respectively the positions corresponding to the negative distance between the push piston assembly 300 and the inner wall surface during the movement, that is, the two positions where the crescent ring 340 of the push piston assembly 300 is in maximum contact with the inner wall surface during the movement. For example, the angle formed between the first groove 110 and the second groove 120 can be 130°.

[0036] Optionally, the sizes of the two grooves are matched with the crescent ring 340, and the shapes of the two grooves are both crescent-shaped.

[0037] In this way, by arranging the first crescent-shaped groove 110 and the second crescent-shaped groove 120 on the inner wall surface of the refrigerator crankcase 100, without increasing the outer dimensions of the crankcase 100, it is possible to provide space for the reciprocating motion of the rotating structure (i.e., the crescent ring 340 of the connecting rod 500 driving the push piston assembly 300), thereby increasing the mechanical motion space of the compression piston assembly 200 and the push piston assembly 300 in the refrigerator, and further reducing the radial outer dimensions of the crankcase 100 while ensuring the performance of the refrigerator.

[0038] In some optional embodiments, such as Figure 2 As shown, the compression piston assembly 200 includes a compression cylinder 210 , a compression piston 220 , a compression piston pad 230 , a pin 240 , a first deep groove ball bearing 250 , and a second deep groove ball bearing 260 .

[0039] Specifically, a gap seal is formed between the compression cylinder 210 and the compression piston 220, and the compression piston pad 230 and the compression piston 220 are connected by adhesive; one end of the connecting rod 500 is rotatably connected to the pin 240 through the first deep groove ball bearing 250, and the connecting rod 500 is connected to the outer ring of the first deep groove ball bearing 250 by adhesive, and the other end of the connecting rod 500 is rotatably connected to the eccentric part of the rotor spring assembly 410 through the second deep groove ball bearing 260; the first deep groove ball bearing 250 and the pin 240 are in sliding fit, and the pin 240 and the compression piston 220 and the compression piston pad 230 are connected by adhesive.

[0040] Thus, by adding the compression piston pad 230 and gluing it to the compression piston 220, the contact area between the pin 240 and the wall surface can be increased, and the friction force of the pin 240 can be increased, thereby reducing the risk of the pin 240 falling off in a harsh environment and improving the mechanical reliability of the refrigerator. The compression piston 220 can also increase the wall thickness to achieve the effect of increasing the contact area and friction force between the pin 240 and the wall surface, thereby reducing the risk of the pin 240 falling off in a harsh environment and improving the reliability of the refrigerator.

[0041] Furthermore, in some embodiments, Figure 1 and Figure 2As shown, the rotor spring assembly 410 specifically includes an eccentric shaft 411, a balance ring 412, a motor rotor 413, a spring 414 and a third deep groove ball bearing 415. Specifically, the eccentric shaft 411 and the balance ring 412 are connected by adhesive, and the eccentric shaft 411 and the motor rotor 413 are connected by adhesive, the eccentric shaft 411 is used as a guide shaft of the spring 414, the spring 414 is placed on the upper part of the rotor spring assembly 410, and the third deep groove ball bearing 415 is arranged in the direction along the eccentric shaft 411. Therefore, the spring 414 can be used to provide a preload force to the third deep groove ball bearing 415.

[0042] It can be understood that in this embodiment, the spring 414 is placed on the upper part of the rotor spring assembly 410 to provide a preload force for the bearing in the direction of the eccentric shaft 411 of the refrigerator (i.e., the third deep groove ball bearing 415). Compared with the method of using gaskets (such as wave washers, spring washers) to provide preload force in the related art, the method of providing bearing preload force through spring 414 can improve the rigidity of the bearing, reduce the vibration and noise of the bearing, and improve the rotation accuracy of the bearing.

[0043] Furthermore, in some embodiments, Figure 1 and Figure 2 As shown, the motor stator assembly 420 specifically includes a motor stator 421 and a housing 422. Specifically, the motor stator 421 and the housing 422 are connected by adhesive, and the motor stator 421 adopts a DC brushless motor stator without a Hall element, which saves space for installing the Hall element and can effectively reduce the height of the refrigerator.

[0044] also, Figure 4 FIG. 1 shows a cross-sectional view of the fourth deep groove ball bearing portion at the bottom of the crankcase 100 of the micro-rotary integral Stirling refrigerator of this embodiment. Figure 4 As shown, the fourth deep groove ball bearing 910 is fixed to the bottom of the crankcase 100 by a retaining ring 920, and the retaining ring 920 is arranged on the outer ring of the fourth deep groove ball bearing 910. In addition, the inner ring of the fourth deep groove ball bearing 910 is connected to the sleeve 930 by gluing.

[0045] Optionally, the shape of the retaining spring 920 is a polygon, such as but not limited to: a hexagon or an octagon.

[0046] In the related art, in order to prevent the bearing and the housing from being separated during the operation of the bearing and failing to play a fixing role, a layer of glue is usually applied to the outer ring of the bearing to glue the bearing to the housing. However, due to the direct contact between the two metal parts, the state of their surface has a great impact on the use of the bearing, resulting in a reduction in its actual service life, such as surface defects or poor surface roughness. Therefore, in this embodiment, the fourth deep groove ball bearing 910 is fixed by a retaining spring 920, which can reduce the impact of the roughness of the bearing assembly surface (i.e., the mating surface with the outer ring of the bearing) on ​​the bearing compared to the related art, thereby facilitating the repeated assembly and use of the crankcase and the bearing.

[0047] It can be seen that the miniature rotary integral Stirling refrigerator of this embodiment is fixed by the threaded collar 600 to replace the sealing and clamping structure of the screws, and the groove is arranged on the inner wall surface of the crankcase 100, which can reduce the size and height of the refrigerator and realize the miniaturized design of the rotary integral Stirling refrigerator; by adding the compression piston pad 230, the rigidity of the bearing can be improved, and the risk of the pin 240 falling off in a harsh environment can be reduced, so as to realize the high reliability design of the rotary integral Stirling refrigerator. That is, a miniaturized and highly reliable rotary Stirling refrigerator for a high operating temperature infrared detector is provided.

[0048] It should be noted that the above describes some embodiments of the present application. Other embodiments are within the scope of the attached claims. Reference to "embodiments" in the present application means that the specific features, structures or characteristics described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0049] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" 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 elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0050] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0051] The term "plurality" used in the present application refers to two or more (including two).

[0052] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0053] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0054] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A miniature rotary integral Stirling refrigerator, characterized in that: include: A crankcase, a compression piston assembly, a push piston assembly and a motor component, wherein the motor component includes a motor stator assembly, a rotor spring assembly and a rotor protective sleeve; The compression piston assembly, the push piston assembly and the rotor spring assembly are all arranged in the crankcase, the motor stator assembly is arranged above the crankcase, and the crankcase and the rotor protection sleeve are pressed and fixed by a threaded clamp ring; The compression piston assembly is connected to the push piston assembly through a connecting rod, the compression piston assembly is connected to the rotor spring assembly through the connecting rod, and the motor stator assembly and the rotor spring assembly are isolated from each other through a rotor protective sleeve.

2. The miniature rotary integral Stirling refrigerator according to claim 1, characterized in that: The external thread of the threaded collar is threadably engaged with the internal thread on the crankcase.

3. The miniature rotary integral Stirling refrigerator according to claim 1, characterized in that: The inner wall surface of the crankcase is provided with at least two grooves, and the positions of the at least two grooves correspond to the positions where the negative distance between the push piston assembly and the inner wall surface exists during the movement of the push piston assembly.

4. The miniature rotary integral Stirling refrigerator according to claim 3, characterized in that: The push piston assembly includes a push piston, a crescent ring and a pin, one end of the crescent ring is rotatably connected to the connecting rod through the pin, and the other end of the crescent ring is rotatably connected to the push piston through the pin; The sizes of the two grooves are matched with the crescent ring, and the shapes of the two grooves are both crescent-shaped.

5. The miniature rotary integral Stirling refrigerator according to claim 4, characterized in that: It also includes a cold finger, wherein the crankcase and the cold finger are fixed by screws; The push piston assembly also includes a cold storage device and a push cylinder. A gap seal is formed between the push piston and the push cylinder. The push piston is connected to the cold storage device through threads. The cold storage device reciprocates in the cold finger.

6. The miniature rotary integral Stirling refrigerator according to claim 1, characterized in that: The compression piston assembly includes a compression cylinder, a compression piston, a compression piston pad, a pin, a first deep groove ball bearing and a second deep groove ball bearing; A gap seal is formed between the compression cylinder and the compression piston, and the compression piston pad is connected to the compression piston by adhesive; One end of the connecting rod is rotatably connected to the pin shaft through a first deep groove ball bearing, the connecting rod is connected to the outer ring of the first deep groove ball bearing by gluing, and the other end of the connecting rod is rotatably connected to the eccentric part of the rotor spring assembly through a second deep groove ball bearing; The first deep groove ball bearing is slidably matched with the pin shaft, and the pin shaft is connected to the compression piston and the compression piston pad by gluing.

7. The miniature rotary integral Stirling refrigerator according to claim 1, characterized in that: The rotor spring assembly includes an eccentric shaft, a balancing ring, a motor rotor, a spring and a third deep groove ball bearing; The eccentric shaft is glued to the balance ring, the eccentric shaft is glued to the motor rotor, the eccentric shaft is a guide shaft of the spring, and the third deep groove ball bearing is arranged in the direction along the eccentric shaft; The spring is used to provide a preload force to the third deep groove ball bearing.

8. The miniature rotary integral Stirling refrigerator according to claim 1, characterized in that: It also includes a fourth deep groove ball bearing, which is fixed to the bottom of the crankcase through a retaining spring.

9. The miniature rotary integral Stirling refrigerator according to claim 8, characterized in that: The retaining spring is arranged on the outer ring of the fourth deep groove ball bearing, and the retaining spring is in a polygonal shape.

10. The micro rotary integral Stirling refrigerator according to claim 8, characterized in that: The inner ring of the fourth deep groove ball bearing is adhesively connected to the shaft sleeve.

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