Expander assembly of Stirling cryocooler and Stirling cryocooler

Abstract

The expander assembly of the Stirling cryocooler comprises a cold finger provided with a cold finger air cylinder, a cold finger air cylinder, a cold finger air cylinder and an expander assembly, a shell of the regenerator is in clearance fit with the cold finger air cylinder; the base is connected with the cold finger, and a gas flowing cavity is formed in the base; the spring is respectively connected with the base and the regenerator shell; the expansion machine assembly further comprises a lining connected with the outer wall face of the regenerator shell. The hot end air cylinder is connected and matched with the cold finger air cylinder in a sleeved mode and connected with the inner wall face of the cold finger air cylinder, the hot end air cylinder is arranged outside the lining in a sleeved mode, and the hot end air cylinder and the lining are in clearance seal. According to the application, only the dynamic gap of the hot end cylinder and the lining needs to be sealed, and the gap between the whole regenerator shell and the whole cold finger cylinder does not need to meet the gap sealing requirement, so that the sealing length can be greatly reduced, and meanwhile, the universality between the cold finger cylinder and the regenerator is not influenced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of stirling cryocooler, especially a kind of expansion machine component of stirling cryocooler and stirling cryocooler. BACKGROUND

[0002] The existing stirling cryocooler is generally compressed by compressor gas working medium, and then generates pneumatic force to push the movement of expansion piston, further pushes the gas working medium between compressor and expander by expansion piston, while maintaining the larger temperature gradient between cold end and hot end.

[0003] Among them, the cold finger cylinder of expander is generally composed of titanium alloy thin-walled cylinder, and uses non-contact gap sealing between expansion piston, to avoid the friction of moving part during movement, which mainly reduces the heat generated by friction during piston movement and the influence of gas leakage on the performance of cryocooler. Because the gap sealing is strict in the size of gap and sealing length, the processing precision of cold finger is required to be higher, the whole section of cold finger cylinder needs high coaxiality and cylindricity, and the cold finger size is required to be processed to appropriate gap size according to the cold finger, resulting in high processing cost.

[0004] At the same time, when the dewar and the cold finger are coupled, the dewar cold finger structure formed by the dewar and the cold finger has poor compatibility with the cold accumulator, and after replacing the dewar or the cold accumulator, the gap sealing of the original matching end may be invalid, affecting the refrigeration effect. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a kind of expansion machine component of stirling cryocooler and stirling cryocooler, which only needs to make hot end cylinder, bushing dynamic gap sealing, without making the gap between entire cold accumulator shell and entire cold finger cylinder meet the gap sealing requirement, so the sealing length can be greatly reduced, and the compatibility between cold finger cylinder and cold accumulator is not affected.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical scheme:

[0007] On the one hand, an expansion machine component of stirling cryocooler is provided, which includes: a cold finger having a cold finger cylinder; a cold accumulator having a cold accumulator shell and an energy storage material filled in the interior of the cold accumulator shell, and the cold accumulator shell and the cold finger cylinder are gap fitted; a base connected to the cold finger and having a gas flow cavity formed inside; and springs respectively connecting the base and the cold accumulator shell;

[0008] The expansion machine component further includes:

[0009] a bushing connected to the outer wall surface of the cold accumulator shell;

[0010] A hot end cylinder is matched with the cold finger cylinder, and connects the inner wall surface of the cold finger cylinder, and the hot end cylinder is arranged outside the bushing and is gap sealed with the bushing.

[0011] Preferably, one end of the cold accumulator housing extends to the outside of the hot end cylinder, and is surrounded by the inner wall surface of the cold finger cylinder to form an expansion cavity, and the other end extends to the inside of the hot end cylinder and is provided with an air inlet.

[0012] Preferably, the outer wall surface of the cold accumulator housing is provided with a recess, and the bushing is arranged in the recess.

[0013] Preferably, the gap between the cold accumulator housing and the cold finger cylinder is greater than the gap between the bushing and the hot end cylinder.

[0014] Preferably, the gap between the cold accumulator housing and the cold finger cylinder is 60-70 μm, and the gap between the bushing and the hot end cylinder is 6-8 μm.

[0015] Preferably, the cold finger cylinder is a variable diameter structure with a stepped portion, which comprises a first cylinder body and a second cylinder body, and the diameter of the first cylinder body is smaller than that of the second cylinder body.

[0016] Preferably, one end of the hot end cylinder is arranged in the second cylinder body, and the stepped surface of the stepped portion faces the end of the hot end cylinder located in the second cylinder body.

[0017] Preferably, the cold finger further comprises a Dewar assembly matched with the cold finger cylinder.

[0018] Preferably, the expander assembly further comprises an O-shaped sealing ring arranged at the matching position of the base and the hot end cylinder, and / or the matching position of the base and the cold finger cylinder.

[0019] In another aspect, a Stirling refrigeration machine comprising the above expander assembly is also provided.

[0020] Compared with the prior art, the expander assembly of the present application has the following advantages:

[0021] In the expander assembly of the present application, when the cold accumulator reciprocates in the cold finger cylinder, only the dynamic gap sealing between the hot end cylinder and the bushing needs to be realized, and the gap between the entire cold accumulator housing and the entire cold finger cylinder does not need to meet the gap sealing requirement, so that the sealing length can be greatly reduced, the precision requirement of the cold finger and the cold accumulator is lowered, and the compatibility between the cold finger cylinder and the cold accumulator is not affected after the Dewar assembly or the cold accumulator is replaced, so that the cold accumulator can be used with different Dewar assemblies. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 Figure 2 is a sectional view of the expander assembly in the utility model.

[0023] Figure 2 Figure 3 is a sectional view of the regenerator in the utility model.

[0024] Figure 3 Figure 4 is an enlarged view of A in figure 2. Figure 1 Figure 5 is an enlarged view of B in figure 2. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the utility model will be apparently and completely described in combination with the drawings in the embodiments of the utility model, obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments, based on the embodiments in the utility model, all other embodiments obtained by the ordinary skilled in the art without creative labor belong to the protection scope of the utility model.

[0026] Embodiment 1

[0027] As shown in figure 2, the embodiment provides an expander assembly of Stirling refrigerator, which comprises: Figures 1-3

[0028] A cold finger, which has a cold finger cylinder 1, in the embodiment, the cold finger cylinder 1 is a cylindrical structure made of titanium alloy material, and the wall thickness is less than 0.2mm, thereby reducing the weight while ensuring the structural strength;

[0029] A regenerator, which has a regenerator shell 3 and energy storage material 31 (such as wire mesh, etc.) filled inside the regenerator shell 3, the regenerator shell 3 is arranged inside the cold finger cylinder 1, and is gap-fitted with the cold finger cylinder 1;

[0030] A bushing 4, which is connected to the outer wall surface of the regenerator shell 3 by bonding or the like;

[0031] A hot end cylinder 2, which is sleeve-fitted with the cold finger cylinder 1, for example, in the embodiment, the hot end cylinder 2 can be entirely or partially sleeve-fitted inside the cold finger cylinder 1, and is connected to the inner wall surface of the cold finger cylinder 1 by bonding or the like, at the same time, the hot end cylinder 2 is sleeve-fitted outside the regenerator shell 3 and the bushing 4, and is gap-sealed with the bushing 4; at the same time, the gap between the regenerator shell 3 and the cold finger cylinder 1 (such as the gap can be 60-70μm) is greater than the gap between the bushing 4 and the hot end cylinder 2 (such as the gap can be 6-8μm).

[0032] A base 7, which is connected to the cold finger, and has a gas flow cavity 71 formed inside;

[0033] And a spring 5; ​

[0034] The cold finger cylinder 1, the accumulator shell 3, and the spring 5 are coaxially arranged; the gas flow cavity 71 is in communication with the inside of the cold finger cylinder 1.

[0035] The cold finger cylinder 1, the accumulator shell 3, and the spring 5 are coaxially arranged; the gas flow cavity 71 is in communication with the inside of the cold finger cylinder 1.

[0036] The motor (including a stator assembly and a rotor assembly) of the Stirling refrigerator drives the eccentric rotating shaft to rotate, so as to drive the compression piston of the compressor assembly to reciprocate, so as to compress the working gas (such as helium). The compressed working gas enters the gas flow cavity 71 through the compression cavity of the compressor assembly and the gas flow channel 72 provided on the base 7, and flows into the hot end cylinder 2, so as to drive the accumulator as a whole to move in the cold finger cylinder 1 and the hot end cylinder 2, away from the base 7. At this time, the spring 5 is elongated. At the same time, the compressed working gas enters the accumulator shell 3 through the gas inlet 33, exchanges heat with the energy storage material 31, so that the temperature of the gas working medium is reduced, so as to realize heat exchange refrigeration. The gas working medium after heat exchange further enters the expansion cavity 32 to expand and refrigerate, and at the same time, drives the accumulator as a whole to move in the cold finger cylinder 1 and the hot end cylinder 2, close to the base 7. At this time, the spring 5 is compressed. The expanded gas working medium can be recycled in the compression cavity.

[0037] The structure design and working principle of the motor, the eccentric rotating shaft, and the compressor assembly of the Stirling refrigerator are all prior art, and will not be described in detail.

[0038] Therefore, in the embodiment, when the accumulator reciprocates in the cold finger cylinder 1, only the dynamic gap sealing with the liner 4 at the hot end cylinder 2 is required, and the gap between the entire accumulator shell 3 and the entire cold finger cylinder 1 does not need to meet the gap sealing requirement. Therefore, the sealing length can be greatly reduced, the precision requirement of the cold finger and the accumulator is reduced, and the processing difficulty and cost are reduced.

[0039] Embodiment 2:

[0040] The difference between the embodiment and the embodiment 1 is that, as shown in Figure 2 The outer wall surface of the accumulator shell 3 is provided with a recess 34, and the liner 4 is arranged in the recess 34, and the outer wall surface of the liner 4 is not lower than the outer wall surface of the accumulator shell 3.

[0041] In addition, as shown in Figure 3As shown, the cold finger cylinder 1 is a variable diameter structure with a stepped portion 13, which includes a first cylinder body 11 and a second cylinder body 12, both of which are integrally formed, and the diameter of the first cylinder body 11 is smaller than that of the second cylinder body 12; the hot end cylinder 2 is sleeved in the second cylinder body 12, and the stepped surface 131 of the stepped portion 13 faces the one end of the hot end cylinder 2 in the second cylinder body 12, so that the hot end cylinder 2 is axially limited by the stepped portion 13.

[0042] Embodiment 3:

[0043] The difference between the embodiment and any one of embodiments 1 or 2 is that the cold finger further includes a Dewar assembly 8 matched with the cold finger cylinder 1 to form a Dewar cold finger structure, for example, in the embodiment, the cold finger cylinder 1 is assembled inside the Dewar assembly 8.

[0044] Embodiment 4:

[0045] The difference between the embodiment and any one of embodiments 1-3 is that the expander assembly further includes an O-ring 6 arranged at the matching position of the base 7 and the hot end cylinder 2 and / or the matching position of the base 7 and the cold finger cylinder 2 to prevent gas leakage.

[0046] Embodiment 4:

[0047] The embodiment provides a Stirling cryogenic refrigerator, which includes the expander assembly according to any one of embodiments 1-4.

[0048] In the expander assembly, the cold finger cylinder 1 is a variable diameter structure with a stepped portion 13, which includes a first cylinder body 11 and a second cylinder body 12, both of which are integrally formed, and the diameter of the first cylinder body 11 is smaller than that of the second cylinder body 12; the hot end cylinder 2 is sleeved in the second cylinder body 12, and the stepped surface 131 of the stepped portion 13 faces the one end of the hot end cylinder 2 in the second cylinder body 12, so that the hot end cylinder 2 is axially limited by the stepped portion 13.

[0049] The above only describes the preferred embodiments of the utility model, and does not limit the utility model, and any modification, equivalent replacement, improvement, etc. within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. An expander assembly of a Stirling cryocooler comprising: A cold finger having a cold finger cylinder; a cold accumulator having a cold accumulator shell and an energy storage material filled in the inside of the cold accumulator shell, and the cold accumulator shell is in clearance fit with the cold finger cylinder; a base connected with the cold finger and having a gas flow cavity formed in the inside thereof; and springs connected with the base and the cold accumulator shell respectively; The expansion machine assembly further comprises: a bushing connected with the outer wall surface of the cold accumulator shell; a hot end cylinder in interference fit with the cold finger cylinder and connected with the inner wall surface of the cold finger cylinder, and the hot end cylinder is sleeved outside the bushing and is in clearance seal with the bushing.

2. The expander assembly of claim 1, wherein, The cold accumulator shell extends to the outside of the hot end cylinder at one end and forms an expansion cavity together with the inner wall surface of the cold finger cylinder, and extends to the inside of the hot end cylinder at the other end and is provided with an air inlet.

3. The expander assembly of claim 1, wherein, The outer wall surface of the cold accumulator shell is provided with a recess, and the bushing is arranged in the recess.

4. The expander assembly of claim 3, wherein, The clearance between the cold accumulator shell and the cold finger cylinder is greater than the clearance between the bushing and the hot end cylinder.

5. The expander assembly of claim 3, wherein, The clearance between the cold accumulator shell and the cold finger cylinder is 60-70μm, and the clearance between the bushing and the hot end cylinder is 6-8μm.

6. The expander assembly of claim 1, wherein, The cold finger cylinder is a variable diameter structure having a stepped portion, which comprises a first cylinder body and a second cylinder body, and the diameter of the first cylinder body is smaller than that of the second cylinder body.

7. The expander assembly of claim 6, wherein The hot end cylinder is sleeved in the second cylinder body at one end, and the stepped surface of the stepped portion faces the end of the hot end cylinder located in the second cylinder body.

8. The expander assembly of claim 1, wherein, The cold finger further comprises a Dewar assembly matched with the cold finger cylinder.

9. The expander assembly of claim 1, wherein, The expansion machine assembly further comprises: an O-ring arranged at the matching position of the base and the hot end cylinder, and / or the matching position of the base and the cold finger cylinder.

10. A Stirling cryocooler characterised in that, The expansion machine assembly comprises the expansion machine assembly according to any one of claims 1-9. The expansion machine assembly comprises the expansion machine assembly according to any one of claims 1-9.

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