Expander assembly and Stirling refrigerator

Abstract

The expansion machine assembly comprises an expansion machine base, a cold finger connected with the expansion machine base in a sealed mode and a pushing assembly located in the expansion machine base and the cold finger, and an expansion cavity is formed through the cold finger and the pushing assembly. And the magnetic spring assembly is arranged close to the expansion cavity and used for generating magnetic acting force applied to the pushing assembly, and the acting direction of the magnetic acting force is opposite to the moving direction of the pushing assembly in the moving process. The magnetic part is continuously located in the low-temperature environment so as to continuously have larger magnetic flux, the magnetic part is prevented from falling off due to degumming, meanwhile, the overall size of the product is further reduced, and the product structure is more compact.

Description

Technical Field

[0001] The present invention relates to the field of Stirling refrigerators, and in particular to an expander assembly and a Stirling refrigerator. Background Art

[0002] Existing Stirling refrigerators usually use a compressor to compress the gas working medium, thereby generating pneumatic force to drive the guide piston of the expander to move, and further drive the push assembly to reciprocate in the cold finger through the guide piston to achieve a refrigeration effect.

[0003] Among them, as shown in the technical solution with application number 202322895752.6 and patent name "A Stirling Refrigerator Expander and Stirling Refrigerator", leaf springs, column springs, etc. are usually used to connect with the piston, and the stiffness of the system is controlled by adjusting the spring. However, the use of mechanical springs will increase the axial or radial dimensions of the expander, making it impossible to miniaturize the expander. In addition, due to the reciprocating motion of the push assembly, the mechanical spring has the risk of fatigue fracture, resulting in failure of the refrigerator. Summary of the invention

[0004] The object of the present invention is to provide an expander assembly and a Stirling refrigerator, wherein the magnetic parts are continuously in a low temperature environment to continuously have a larger magnetic flux and avoid the magnetic parts from falling off due to debonding, while helping to further reduce the overall volume of the product and making the product structure more compact.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] On the one hand, an expander assembly of a Stirling refrigerator is provided, which includes: an expander base, a cold finger sealed to the expander base, and a push assembly located in the expander base and the cold finger, wherein an expansion chamber is formed by the cold finger and the push assembly; and a magnetic spring assembly, which is arranged close to the expansion chamber and is used to generate a magnetic force applied to the push assembly, and the direction of action of the magnetic force is opposite to the direction of movement of the push assembly when the push assembly moves.

[0007] Preferably, the magnetic spring assembly comprises:

[0008] An internal magnetic member, which is arranged inside one end of the cold storage shell of the pushing assembly close to the expansion chamber and connected to the inner wall surface of the cold storage shell;

[0009] An external magnetic member, which is arranged outside the cold finger cylinder of the cold finger, corresponds to the position of the expansion chamber, and is connected to the outer wall surface of the cold finger cylinder;

[0010] The internal magnetic part and the external magnetic part are magnetized in a radial manner, and the magnetization directions are the same.

[0011] Preferably, the internal magnetic component and the external magnetic component are both permanent magnets.

[0012] Preferably, the internal magnetic component is an integral ring-shaped structure, or an annular split structure formed by splicing multiple component units, and / or the external magnetic component is an integral ring-shaped structure, or an annular split structure formed by splicing multiple component units.

[0013] Preferably, the magnetic spring assembly further comprises: an internal magnetic component limiter connected to the cold storage device housing and used for limiting the axial position of the internal magnetic component.

[0014] Preferably, the magnetic spring assembly further comprises: an external magnetic component limiter connected to the outer wall surface of the cold finger cylinder and used for limiting the axial position and / or radial position of the external magnetic component.

[0015] Preferably, the external magnetic part limiter includes: a radial limiter, which is located as a whole on the periphery of the external magnetic part and one end of which is connected to the lower surface of the cold plate for closing the end opening of the cold finger cylinder, and / or an axial limiter, which is located as a whole below the external magnetic part and one end of which is connected to the outer wall surface of the cold finger cylinder.

[0016] Preferably, the free end of the radial limiting portion and the free end of the axial limiting portion are connected to form a structure with an "L" shape in longitudinal section.

[0017] Preferably, the expander assembly further comprises: a cylinder fitting seal, which is used to seal the fitting position of the guide cylinder and the cold finger of the push assembly.

[0018] Preferably, the expander assembly further comprises: a cold finger mating seal, which is used to seal the mating point between the cold finger and the expander base.

[0019] On the other hand, a Stirling refrigerator is also provided, which includes the above-mentioned expander assembly.

[0020] In summary, the present invention has the following beneficial effects compared with the prior art:

[0021] The magnetic parts in the present invention are continuously in a low-temperature environment to continuously have a larger magnetic flux, thereby avoiding the situation where the magnetic spring stiffness becomes smaller due to the attenuation of the magnetic flux of the magnetic parts in a high-temperature environment. At the same time, it helps to further reduce the overall volume of the product, making the product structure more compact. In addition, since the magnetic parts are in a low-temperature environment, the adhesive used for bonding can maintain the bonding performance for a long time, avoiding the magnetic parts from falling off due to debonding. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a cross-sectional view of the expander assembly in the present invention.

[0023] Figure 2 It is a schematic diagram of the magnetization direction of the internal magnetic part and the external magnetic part in the present invention. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] like Figure 1 As shown, this embodiment provides an expander assembly of a Stirling refrigerator, which includes:

[0027] Expander base 12;

[0028] A cold finger 3 is sealed and connected to the expander base 12, and has a cold finger cylinder 31. In this embodiment, the opening of the cold finger cylinder 31 at one end away from the expander base 12 is closed by a cold plate 1. For example, the cold plate 1 can be connected to the end of the cold finger cylinder 31 by welding, bonding, etc. to close the end opening. At the same time, the cold finger cylinder 31 is a cylindrical structure made of titanium alloy material, and the wall thickness is less than 0.2 mm, thereby reducing the weight while ensuring the structural strength; at the same time, the structure after the expander base 12 and the cold finger 3 are sealed and connected has an internal cavity 100, and the internal cavity 100 includes a back pressure cavity 101 close to the expander base 12 and a room temperature cavity 102 close to the cold finger cylinder 31, and the back pressure cavity 101 and the room temperature cavity 102 are interconnected;

[0029] A cold storage device, which comprises a cold storage device shell 15 and an energy storage material 6 (such as a wire mesh, etc.) filled inside the cold storage device shell 15, wherein one end of the cold storage device shell 15 extends into the inside of the cold finger cylinder 31, and is enclosed with the inner wall surface of one end of the cold finger cylinder 31 away from the expander base 12 and the cold plate 1 to form an expansion cavity 33, and the cold storage device shell 15 and the cold finger cylinder 31 are clearance-matched;

[0030] A guide cylinder 7 is disposed inside the internal cavity 100 and connected to the inner wall surface of the cold finger 3 and / or the inner wall surface of the expander base 12 by bonding or the like; further, an air inlet hole 32 communicating with the inside of the guide cylinder 7 is also provided on the cold finger 3;

[0031] A guide piston 8, one end of which is located inside the guide cylinder 7, and is connected to one end of the cold accumulator close to the expander base 12 (such as connecting to one end of the cold accumulator housing 15 close to the expander base 12) by bonding, welding, etc., and the other end passes through the guide cylinder 7 and extends into the back pressure chamber 101, and the guide piston 8 and the guide cylinder 7 are clearance-matched; preferably, the guide piston 8 is a stepped shaft structure to form a two-stage clearance sealing structure with the guide cylinder 7; the cold accumulator, the guide cylinder 7, and the guide piston 8 constitute a push assembly;

[0032] and a magnetic spring assembly, which is arranged near the expansion chamber 33 and is used to generate a magnetic force applied to the push assembly, and the direction of action of the magnetic force is opposite to the direction of movement of the push assembly when the working fluid gas drives the push assembly to move synchronously;

[0033] The cold finger cylinder 31, the cold storage housing 15, the guide cylinder 7, and the guide piston 8 are coaxially arranged.

[0034] The motor (including the stator assembly and the rotor assembly) of the Stirling refrigerator drives the eccentric shaft to rotate, so as to drive the compression piston of the compressor assembly to reciprocate, so as to compress the working fluid gas (such as helium). The compressed working fluid gas enters the room temperature chamber 102 through the connecting pipe and the air inlet 32, so as to push the guide piston 8 and the cold storage device as a whole to move synchronously inside the cold finger 3 and the guide cylinder 7 in a direction away from the back pressure chamber 101. At the same time, the compressed working fluid gas enters the cold storage device housing 15, and heat is exchanged through the energy storage material 6, so that the temperature of the gas working fluid is reduced to realize heat exchange refrigeration. After the heat exchange is completed, the gas working fluid further enters the expansion chamber 33 for expansion and refrigeration, and at the same time pushes the guide piston 8 of the push assembly and the cold storage device as a whole to move synchronously inside the cold finger 3 and the guide cylinder 7 in a direction close to the back pressure chamber 101 in the opposite direction. The expanded gas working fluid can re-enter the compression chamber for recycling;

[0035] At the same time, when the guide piston 8 of the push assembly and the cold storage device as a whole move synchronously under the drive of the gas working fluid, the magnetic spring assembly generates a magnetic force in the opposite direction of the movement of the guide piston 8 and the cold storage device when they move synchronously, so as to provide a stable spring restoring force within the travel range of the guide piston 8, thereby making the guide piston 8 operate stably within the travel range.

[0036] Therefore, in this embodiment, the magnetic spring assembly can replace the mechanical spring in the prior art (such as leaf spring, column spring, etc.) to provide a spring restoring force to ensure that the guide piston moves stably within the stroke range. At the same time, the axial or radial size of the expander can be reduced to achieve miniaturization of the expander, while avoiding the failure of the refrigerator due to the risk of fatigue fracture of the mechanical spring.

[0037] Embodiment 2:

[0038] The difference between this embodiment and embodiment 1 is that the magnetic spring assembly includes:

[0039] An internal magnetic member 5, which is disposed inside one end of the cold storage housing 15 close to the expansion chamber 33 and connected to the inner wall surface of the cold storage housing 15 by bonding, welding, etc.;

[0040] The external magnetic member 13 is arranged outside the cold finger cylinder 31 and corresponds to the position of the expansion chamber 33, and is connected to the outer wall surface of the cold finger cylinder 31 by bonding, welding, etc.;

[0041] Further, the internal magnetic member 5 is an annular integral structure, or an annular split structure formed by splicing multiple components (such as multiple magnetic tiles), and / or the external magnetic member 13 is an annular integral structure, or an annular split structure formed by splicing multiple components (such as multiple magnetic tiles);

[0042] At the same time, the internal magnetic member 5 and the external magnetic member 13 are both permanent magnets (such as magnetic steel, etc.), and Figure 2 As shown, the internal magnetic member 5 and the external magnetic member 13 are magnetized in a radial manner, and the magnetization directions of the two are the same (such as both radially outward, or both radially inward);

[0043] When the internal magnetic component 5 is located at the initial position (for example, at the middle position of the external magnetic component 13), the resultant magnetic force exerted on it by the external magnetic component 13 is zero. When the internal magnetic component 5, the guide piston 8 and the cold storage device reciprocate synchronously, the internal magnetic component 5 deviates from the initial position, the resultant magnetic force exerted on it by the external magnetic component 13 is not zero, and the direction of the resultant force is opposite to the direction of its movement, thereby producing a restoring effect similar to that of a mechanical spring. Furthermore, in this embodiment, the size and material of the internal magnetic component 5 and the external magnetic component 13 can be adjusted to achieve the adjustment of the magnetic force.

[0044] Therefore, this embodiment makes full use of the internal space of the cold storage housing 15 and the external space of the cold finger cylinder 31 to arrange the magnetic parts, which can make the structure of the expander more compact. At the same time, the magnetic spring assembly is arranged as a whole at the cold end, that is, near the expansion chamber 33, so that the internal magnetic part 5 and the external magnetic part 13 are continuously in a low temperature environment, so as to continuously have a larger magnetic flux (relative to the magnetic part being in a high temperature environment), thereby avoiding the situation where the magnetic spring stiffness decreases due to the attenuation of the magnetic flux of the magnetic part in a high temperature environment. At the same time, having a large magnetic flux for a long time can further reduce the volume of the magnetic part, which helps to further reduce the overall volume of the product. In addition, when the internal magnetic part 5 and the external magnetic part 13 are installed by bonding, since the internal magnetic part 5 and the external magnetic part 13 are in a low temperature environment, the adhesive used for bonding can maintain the bonding performance for a long time, avoiding the magnetic part from falling off due to debonding.

[0045] Embodiment 3:

[0046] The difference between this embodiment and embodiment 1 or 2 is that the magnetic spring assembly further includes:

[0047] An internal magnetic part stopper 4, which is connected to the cold storage housing 15 by bonding, welding, etc., and is used to limit the axial position of the internal magnetic part 5 to prevent the internal magnetic part 5 from falling out of the cold storage housing 15;

[0048] and an external magnetic part stopper 2, which is connected to the outer wall surface of the cold finger cylinder 31 by bonding, welding, etc., and is used to limit the axial position and / or radial position of the external magnetic part 13 to prevent the external magnetic part 13 from falling off;

[0049] For example, in this embodiment, the external magnetic member stopper 2 includes: a radial stopper 21, which is entirely located at the periphery of the external magnetic member 13 and one end of which is connected to the lower surface of the cold plate 1, and / or an axial stopper 22, which is entirely located below the external magnetic member 13 and one end of which is connected to the outer wall surface of the cold finger cylinder 31;

[0050] Preferably, the external magnetic part limiter 2 has both a radial limiter 21 and an axial limiter 22, and the end of the radial limiter 21 not connected to the cold plate 1 (i.e., the free end) is connected to the end of the axial limiter 22 not connected to the outer wall of the cold finger cylinder 31 (i.e., the free end) to form a structure with an "L"-shaped longitudinal section, and the radial limiter 21 and the axial limiter 22 can be integrally formed.

[0051] Embodiment 4:

[0052] The difference between this embodiment and any one of embodiments 1-3 is that the expander assembly further includes:

[0053] The cylinder matching seal is used to seal the matching position between the guide cylinder 7 and the cold finger 3. For example, the cylinder matching seal in this embodiment includes a first seal 9, which is used to seal the matching position between the end of the guide cylinder 7 away from the expander base 12 and the cold finger 3, and / or a second seal 10, which is used to seal the matching position between the end of the guide cylinder 7 close to the expander base 12 and the cold finger 3; the cylinder matching seal includes an O-ring;

[0054] And / or, a cold finger matching seal 11 is used to seal the matching position between the cold finger 3 and the expander base 12. Preferably, the cold finger matching seal 11 includes a C-ring or an O-ring.

[0055] Therefore, different seals can be used to achieve sealing at the joints of different components, avoiding air cross-talk and leakage that affect the refrigeration efficiency.

[0056] Embodiment 5:

[0057] This embodiment provides a Stirling refrigerator, which includes the expander assembly described in any one of Embodiments 1-4.

[0058] In summary, the present invention arranges the magnetic spring assembly as a whole at the cold end, so that the magnetic part is continuously in a low-temperature environment to continuously have a larger magnetic flux, thereby avoiding the situation where the magnetic spring stiffness becomes smaller due to the attenuation of the magnetic flux of the magnetic part in a high-temperature environment. At the same time, having a large magnetic flux for a long time can further reduce the volume of the magnetic part, which helps to further reduce the overall volume of the product and make the product structure more compact. In addition, since the magnetic part is in a low-temperature environment, the adhesive used for bonding can maintain the bonding performance for a long time, avoiding the magnetic part from falling off due to debonding.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An expander assembly of a Stirling refrigerator, comprising: An expander base, a cold finger sealed with the expander base, and a push assembly located in the expander base and the cold finger, wherein an expansion chamber is formed by the cold finger and the push assembly; Characterized in that the expander assembly also includes: A magnetic spring component is arranged close to the expansion chamber and is used to generate a magnetic force applied to the push component, and the direction of action of the magnetic force is opposite to the direction of movement of the push component.

2. The expander assembly according to claim 1, characterized in that The magnetic spring assembly comprises: An internal magnetic member, which is arranged inside one end of the cold storage shell of the pushing assembly close to the expansion chamber and connected to the inner wall surface of the cold storage shell; An external magnetic member, which is arranged outside the cold finger cylinder of the cold finger, corresponds to the position of the expansion chamber, and is connected to the outer wall surface of the cold finger cylinder; The internal magnetic part and the external magnetic part are magnetized in a radial manner, and the magnetization directions are the same.

3. The expander assembly according to claim 2, characterized in that The internal magnetic part and the external magnetic part are both permanent magnets.

4. The expander assembly according to claim 2, characterized in that The internal magnetic component is an integral ring-shaped structure, or an annular split structure formed by splicing multiple components, and / or the external magnetic component is an integral ring-shaped structure, or an annular split structure formed by splicing multiple components.

5. The expander assembly according to claim 2, characterized in that The magnetic spring assembly further includes: an internal magnetic component limiting component, which is connected to the cold storage device housing and is used to limit the axial position of the internal magnetic component.

6. The expander assembly according to claim 2, wherein: The magnetic spring assembly further includes: an external magnetic part limiter connected to the outer wall surface of the cold finger cylinder and used for limiting the axial position and / or radial position of the external magnetic part.

7. The expander assembly according to claim 5, characterized in that The external magnetic part limiter includes: a radial limiter, which is located as a whole on the periphery of the external magnetic part and one end of which is connected to the lower surface of the cold plate for closing the end opening of the cold finger cylinder, and / or an axial limiter, which is located as a whole below the external magnetic part and one end of which is connected to the outer wall surface of the cold finger cylinder.

8. The expander assembly according to claim 6, wherein: The free end of the radial limiting portion and the free end of the axial limiting portion are connected to form a structure with an "L" shape in longitudinal section.

9. The expander assembly according to claim 1, wherein: The expander assembly further comprises: a cylinder matching seal, which is used to seal the matching position between the guide cylinder and the cold finger of the push assembly.

10. The expander assembly according to claim 1, wherein: The expander assembly further comprises: a cold finger matching seal, which is used to seal the matching position between the cold finger and the expander base.

11. A Stirling refrigerator, characterized in that: Comprising the expander assembly according to any one of claims 1-9.

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