WO2021033890A1

WO2021033890A1 - Stirling refrigerator

Info

Publication number: WO2021033890A1
Application number: PCT/KR2020/007386
Authority: WO
Inventors: 오성광; 박성혁; 이태환; 이호채
Original assignee: 삼성전자주식회사
Priority date: 2019-08-19
Filing date: 2020-06-08
Publication date: 2021-02-25
Also published as: KR20210021699A

Abstract

A Stirling refrigerator according to an embodiment of the present invention can ensure a lower bending stiffness by comprising a displacer rod and a sealing guide partially surrounding the displacer rod. Further, the Stirling refrigerator can minimize friction by ensuring a hollow portion in a compression piston and appropriately selecting the length of the sealing guide which comes in direct contact with a through-hole. The Stirling refrigerator may further comprise a compensation part configured to compensate for misalignment between the displacer piston, the compression piston, the displacer rod, and the cylinder or bending of the displacer rod. The compensation part may comprise a ball joint, a link, a wire, a resin, a spring, etc. The ensured low bending stiffness and the minimized friction can reduce the precision and manufacturing time required for axial alignment in the manufacturing process. In addition, the refrigeration efficiency of the Stirling refrigerator can also be increased.

Description

Stirling freezer

It relates to a Stirling refrigerator having an improved structure to improve durability.

The Stirling refrigerator may be composed of a compressor that drives a piston and an expander that generates refrigeration. Compressors are divided into a crank drive method and a linear motor drive method according to the driving method, and the expander is composed of a cylinder and a displacer including a regenerator serving as a storage cooling.

The Stirling chiller is the reverse operation of the Stirling thermal chiller and is operated by helium gas and is one of the most basic cryogenic chillers. It has high thermodynamic efficiency, is relatively easy to manufacture, and is widely used from small to large capacity. As the cycle is repeated, the temperature of the cooling unit is lowered in the subsequent cycle compared to the previous cycle, and the lowest temperature of the refrigerator becomes the temperature at which the refrigeration load and the refrigeration capacity are balanced. There are various types of Stirling refrigerators that operate on this principle, but there are α-type, β-type, and γ-types depending on the correlation between the cylinder and the piston. The α-type is a two-piston type, which is the basic type, and the γ-type is an α-type expansion piston. As a structure that has been replaced with a displacer, the displacer acts only to move the working gas. The β-type is a structure in which a piston and a displacer are combined in the same cylinder, and has a compact refrigerator structure.

The next driving mechanism is divided into mechanical type and free piston type. In the mechanical type, the piston is driven by a crank mechanism, so it has high reliability and good control performance. In addition, the free piston type drives the piston by using a linear actuator and forced vibration by the repulsive force of a spring and a working gas. It is compact and has low noise, but the price is high. It is used for recondensing helium or cooling insulation surfaces of vacuum pumps for semiconductor manufacturing, MRI, SMES, and superconducting generators.

Among the above Stirling chillers, β-type free piston Stirling chillers have a constant phase angle with the compression piston by the pressure change of the cylinder gas due to the linear reciprocating motion of the compression piston and the spring reaction force connected to the displacer rod end without the displacer being connected to the actuator. And linearly reciprocate at the same period Since the displacer rod is configured to pass through the compression piston, there is a structural limitation in that the length of the displacer rod becomes longer. In addition, since the distance between the displacer rod and the compression piston through hole is manufactured to a level of 10-30㎛ to prevent leakage of the operating gas, if the alignment of the displacer rod and the compression piston through hole is slightly misaligned, wear may proceed between the displacer rod and the compression piston through hole. . Therefore, the coaxiality of the displacer piston, the displacer rod, the compression piston, the through hole and the cylinder may be required. Due to this, precision processing and assembly are required, resulting in an increase in manufacturing cost, and a large assembly time, which may reduce productivity.

Provides a Stirling refrigerator with improved durability.

Provides a Stirling chiller with increased refrigeration efficiency by minimizing friction between components.

It provides a Stirling chiller that can reduce manpower and manufacturing time for precision of the manufacturing process required for shaft alignment.

The Stirling refrigerator according to the spirit of the present invention includes a case; A cylinder disposed in the case; A compression piston provided to reciprocate in the axial direction inside the cylinder and including a through hole; A displacer piston disposed to be spaced apart from the compression piston in the axial direction; A displacer rod connected to the displacer piston and extending in the axial direction to pass through the compression piston;

And a sealing guide extending in the axial direction from the displacer piston so as to be inserted into the through hole and surrounding a portion of the displacer rod.

When the length of the through hole formed in the compression piston is defined as the first distance, the compression piston may include a hollow portion in the interior spaced by a first distance from the surface of the compression piston facing the displacer piston.

When the distance between the displacer piston and the compression piston is defined as the second distance, the length of the sealing guide may be configured to be equal to the sum of the first distance and the second distance. .

A gap may be formed between the inner peripheral surface of the through hole and the outer peripheral surface of the sealing guide.

The ratio of the diameter of the sealing guide to the diameter of the displacer piston may be composed of 15%-40%.

The displacer rod may further include a compensation unit configured to compensate for misalignment of alignment between the displacer piston, the compression piston, the displacer rod, and the cylinder, or a warpage of the displacer rod.

The Stirling refrigerator may include a displacer spring spaced apart from the compression piston in the axial direction and disposed opposite the displacer piston; A coupling portion in which the displacer rod is coupled to the displacer piston or the displacer spring; It further includes, wherein the coupling unit may further include a compensation unit configured to compensate for a misalignment of alignment between the displacer piston, the compression piston, the displacer rod, and the cylinder, or a warpage of the displacer rod.

The compensation unit may include one or more ball joints configured to be rotatable about an axis perpendicular to the axial direction.

The compensation unit may include one or more links configured to be rotatable about an axis perpendicular to the axial direction.

The displacer rod may contain resin.

The displacer rod may be disposed at the center of a spring having a diameter larger than that of the displacer rod.

The displacer rod may include a wire.

The wire may be disposed at the center of a spring having a diameter larger than that of the wire.

The Stirling refrigerator according to the spirit of the present invention includes: a cylinder; A displacer piston provided to reciprocate in the axial direction inside the cylinder; A compression piston disposed to be spaced apart from the displacer piston in the axial direction and including a through hole extending along the axial direction from a surface of the compression piston facing the displacer piston; A displacer spring spaced apart from the compression piston in the axial direction and disposed on the opposite side of the displacer piston; A displacer rod connected to the displacer piston and extending in the axial direction to pass through the compression piston; And a sealing guide extending in the axial direction from the displacer piston so as to be inserted into the through hole and surrounding a portion of the displacer rod.

The compression piston may include a hollow portion spaced apart from the surface of the compression piston facing the displacer piston, and the hollow portion may be disposed to contact the through hole. The through hole extends along the axial direction from a surface of the compression piston facing the displacer piston, and the extension is a point at which the extension of the sealing guide ends when the displacer piston and the compression piston are spaced apart from each other at a maximum distance and the The through hole and the hollow portion may be formed to be in contact with each other so that the point at which the step is formed is the same.

It is composed of a displacer rod and a sealing guide that partially surrounds it, so that lower bending stiffness can be secured.

It is possible to minimize friction by securing a hollow part in the compression piston and selecting an appropriate length of the sealing guide that directly contacts the through hole.

It is possible to correct displacer piston, compression piston, displacer rod, misalignment between cylinders or warp of displacer rod.

By securing low bending stiffness, friction between the components of the Stirling refrigerator can be minimized. As a result, it is possible to increase the refrigeration efficiency of the Stirling refrigerator.

In addition, due to the lowered bending stiffness of the displacer rod, it may be possible to compensate for axial alignment errors that may occur between components of the Stirling refrigerator. As a result, it is possible to reduce manpower and manufacturing time for the precision of the manufacturing process required for axis alignment.

1 is a cross-sectional view of a Stirling refrigerator according to an embodiment of the present invention.

2 is a perspective view of a Stirling refrigerator according to an embodiment of the present invention.

3 is an exploded perspective view of a Stirling refrigerator according to an embodiment of the present invention.

4 shows an enlarged view of area A of FIG. 1.

5 shows the results of performance evaluation assuming that the diameter of the displacer piston of the Stirling refrigerator according to an embodiment of the present invention is 35 mm.

6 is a perspective view of a displacer of a Stirling refrigerator according to an embodiment of the present invention.

7 shows a cross-sectional view of FIG. 6.

8 is a perspective view of a displacer of a Stirling refrigerator according to another embodiment of the present invention.

9 shows a cross-sectional view of FIG. 8.

10 is a perspective view of a displacer of a Stirling refrigerator according to another embodiment of the present invention.

11 shows a cross-sectional view of FIG. 10.

12 is a perspective view of a displacer of a Stirling refrigerator according to another embodiment of the present invention.

Fig. 13 shows a cross-sectional view of Fig. 12;

14 is a perspective view of a displacer of a Stirling refrigerator according to another embodiment of the present invention.

15 shows a cross-sectional view of FIG. 14.

The embodiments described in the present specification and the configurations shown in the drawings are only preferred examples of the disclosed invention, and there may be various modifications that may replace the embodiments and drawings of the present specification at the time of filing of the present application.

In addition, the same reference numerals or reference numerals shown in each drawing of the present specification indicate parts or components that substantially perform the same function.

In addition, terms used in the present specification are used to describe the embodiments, and are not intended to limit and/or limit the disclosed invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It does not preclude the presence or addition of elements, numbers, steps, actions, components, parts, or combinations thereof.

In addition, terms including ordinal numbers such as "first" and "second" used herein may be used to describe various elements, but the elements are not limited by the terms, and the terms are It is used only for the purpose of distinguishing one component from other components. For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. The term "and/or" includes a combination of a plurality of related stated items or any of a plurality of related stated items.

Meanwhile, the terms "up-down direction", "lower side", and "front-back direction" used in the following description are defined based on the drawings, and the shape and position of each component are not limited by this term.

Specifically, as shown in FIG. 3, the side on which the displacer piston 310 is disposed is set as the front side based on the axial direction X of the Stirling refrigerator 1, and left and right sides and upper and lower sides are defined.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

A Stirling refrigerator according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. In one embodiment of the present invention, a Stirling refrigeration freezer among Stirling refrigerators is disclosed. However, as will be described later, the Stirling engine is composed of a stationary cycle of the Stirling refrigerator. It may also be applicable to Stirling engines that are not limited. 1 is a cross-sectional view of a Stirling refrigerator according to an embodiment of the present invention. 2 is a perspective view of a Stirling refrigerator according to an embodiment of the present invention. 3 is an exploded perspective view of a Stirling refrigerator according to an embodiment of the present invention.

As disclosed in FIG. 1, the Stirling refrigerator 1 includes a case 10, a displacer piston 310, a displacer rod 100, a compression piston 320, and a displacer piston 310 disposed therein. The cylinder 210, the second cylinder 220 in which the compression piston 320 is disposed therein, the actuator 50 for performing linear reciprocation through electrical interaction with the compression piston 320, the compression piston 320, and It may be composed of a compression piston spring 601 connected and a displacer piston spring 602 connected to the displacer rod 100. The first cylinder 210 and the second cylinder 220 may be arranged in separate configurations as shown in FIGS. 1 and 3, but, unlike this, they may be formed as one cylinder 200 as an integral configuration. There is also.

The Stirling refrigerator 1 includes a compression piston 320 that linearly reciprocates by an actuator 50 such as a linear motor, and a displacer piston that linearly reciprocates while maintaining a constant phase angle difference from the compression piston 320. 310) may be included. At this time, the phase angle may achieve 90°.

The compression piston 320 and the displacer piston 310 may complete the stirring cycle by flowing a working gas between the compression unit and the expansion unit. At this time, the working gas may be composed of He, but can be applied to other working gas.

Specifically, the displacer piston 310 and the compression piston 320 may reciprocate the inside of the cylinder 200. In the compression unit, the compression piston 320 and the displacer piston 310 may compress the working gas. The heat generated at this time may be discharged to the outside through the high-temperature heat exchanger 30. That is, the temperature of the working gas in the compression unit may increase, so that the temperature of the compression unit may increase, and heat generated at this time may be discharged to the outside through the high temperature unit heat exchanger 30. As the displacer piston 310 moves, the working gas of the expansion unit may expand. At this time, heat may be absorbed from the outside through the low-temperature heat exchanger 20 to serve as a refrigerator. That is, the temperature of the working gas in the expansion unit decreases, so that the temperature of the expansion unit may decrease. In summary, the temperature of the compression unit may be lowered through external heat dissipation of the high temperature unit heat exchanger 30, and the temperature of the expansion unit may be lowered through external heat absorption of the low temperature unit heat exchanger 20. Cooling power can be generated by repeating such compression and expansion.

As shown in Figure 3, the cylinder 200 may be configured to have a cylindrical space. The cylinder 200 may be formed by coupling separate cylinders with each other, such as the first cylinder 210 and the second cylinder 220. Alternatively, unlike this, the first cylinder 210 and the second cylinder 220 may be integrally formed. The displacer piston 310 may be disposed inside the first cylinder 210 and the compression piston 320 may be disposed inside the second cylinder 220. The displacer piston 310 may be disposed to be spaced apart from the compression piston 320 in an axial direction to be described later.

The displacer piston 310 or the compression piston 320 in the first cylinder 210 and the second cylinder 220 may reciprocate in the axial direction X as shown in FIG. 3. An expansion portion may be formed in front of the displacer piston 310, and a compression portion may be formed in a gap between the displacer piston 310 and the compression piston 320. A regenerator 40 may be disposed between the expansion unit and the compression unit. A working gas such as helium can be filled in the gap. Thereafter, the compression piston 320 may be reciprocated in the axial direction (X) by an actuator 50 such as a linear motor. The reciprocating motion due to such external drive may be performed in various ways if it is possible to drive the compression piston 320 in the axial direction X in addition to the linear motor. The reciprocating motion of the compression piston 320 may generate a periodic pressure fluctuation of the charged working gas and simultaneously cause a reciprocating motion of the displacer piston 310 in the axial direction.

Referring to FIG. 1, as will be described later, the displacer rod 100 extends in an axial direction to pass through the compression piston, and may include one side connected to the displacer piston and the other side connected to the displacer spring. The displacer piston 310 may have the same reciprocation cycle as the compression piston 320, but may reciprocate in a different phase. When the displacer piston 310 and the compression piston 320 move while maintaining an appropriate phase difference, the charged working gas generates a cooling effect in the expansion portion.

The regenerator 40 may be configured by a matrix of fine wires or an annular gap wound around a coil. When the working gas passes through the regenerator 40 from the compression section and moves to the expansion section, the regenerator 40 receives and stores heat. When the working gas passes through the regenerator 40 from the expansion part and returns to the compression part, it is possible to generate a heat storage action of imparting stored heat to the working gas.

Next, the structure of the displacer 90 will be described in detail with reference to FIGS. 1 to 3.

The displacer 90 may specifically include a displacer piston 310, a displacer rod 100, a sealing guide 700, and a displacer piston spring 602.

The displacer piston 310 may have a cylindrical shape corresponding to the shape of the first cylinder 210 as shown in FIGS. 1, 3 and 4. The displacer piston 310 may be configured to include an empty space therein. Through this configuration, the cooling efficiency can be increased by minimizing the energy required for the reciprocating motion of the displacer piston 310. However, depending on the material and shape of the displacer piston 310, it may be provided in a configuration that does not include an empty space therein.

As shown in FIG. 1, the displacer rod 100 may include one side connected to the displacer piston 310 and the other side connected to the displacer piston spring 602. Specifically, the displacer piston 310 and the displacer rod 100 are connected to one side of the displacer rod 100 through the displacer piston 310 as shown in FIG. 1 to form a bolt and nut structure. It can be connected through. Alternatively, the displacer piston 310 and the displacer rod 100 may be integrally formed. Contrary to this, any structure capable of interconnecting the displacer piston 310 and the displacer rod 100 is applicable. It may be connected through a sealing guide 700 to be described later.

A method in which the displacer rod 100 and the displacer piston spring 602 are connected may be connected through a fastening member such as a screw as shown in FIG. 1. In addition, any structure capable of interconnecting the displacer rod 100 and the displacer piston spring 602 is applicable.

As shown in FIG. 1, the displacer rod 100 may pass through the compression piston 320 and be connected to the displacer piston spring 602. Specifically, the displacer rod 100 may be connected to the displacer piston spring 602 by sequentially passing through the through hole 400 and the hollow part 500 formed in the compression piston 320.

As shown in FIG. 1, the sealing guide 700 may extend in the axial direction from the displacer piston 310 to be inserted into the through hole 400. In addition, it may be configured to surround a portion of the displacer rod 100. When the sealing guide 700 is inserted into the through hole 400, the distance between the outer circumferential surface of the sealing guide 700 and the through hole 400 may be 10-30 μm so that the working gas does not leak.

As shown in FIGS. 1 and 3, the compression piston 320 may be disposed inside the second cylinder 220 and may be configured in a cylindrical shape corresponding to the shape of the second cylinder 220. The compression piston 320 may be disposed to be located inside the actuator 50. That is, the actuator 50 may be positioned to surround the outer peripheral surface of the second cylinder 220. The compression piston 320 located inside the second cylinder 220 may be supported by the first support part 60 as shown in FIGS. 1 and 3. The first support may be referred to as a moving magnet. The second support 70 may be disposed to fix the actuator and the compression piston spring 601. As shown in Figs. 1 and 3, the second support unit may have two configurations, and otherwise, it may be formed integrally. Among the two configurations, a configuration facing the compression piston spring 601 may be referred to as a spring bracket 70. The rest of the configuration may be referred to as the actuator bracket 70. That is, the actuator bracket 70 may be disposed to fix the actuator 50, and the spring bracket 70 may be disposed to fix the compression piston spring 601. In addition, the compression piston 320 has one side connected to the compression piston spring 601 so that when the compression piston 320 is moved in the axial direction by the actuator 50, the compression piston 320 receives a restoring force in the opposite direction, so that a reciprocating motion may be possible. .

As shown in FIG. 1, the compression piston 320 may be configured to include an empty space 900 in an area close to the outer circumferential surface C. Through this configuration, it is possible to increase the cooling efficiency by minimizing the energy required for the reciprocating motion of the compression piston 320. However, depending on the material and shape of the compression piston 320, it may be provided in a configuration that does not include the empty space 900 therein.

The compression piston 320 may include a through hole 400 formed with a predetermined length L1 along the compression piston 320 axial direction X, as shown in FIGS. 1 and 4. The through hole 400 may be formed in a cylindrical shape corresponding to the shape of the displacer rod 100 or the shape of the sealing guide 700 to be described later. The length of the cylindrical shape, that is, the predetermined length L1 formed along the axial direction X may be specifically formed as follows. When the displacer piston 310 and the compression piston 320 are separated at the maximum, the point at which the extension of the sealing guide 700 toward the displacer spring 602 ends, and the through hole 400 and the hollow part 500 are It may be formed so that the point where the step is formed in contact with each other is coincident. A gap G3 between the sealing guide 700 and the through hole 400 shown in FIG. 4 may be formed to be about 10 to 30 μm. That is, it may be configured to prevent leakage of the working gas by maintaining the very small gap G3.

The compression piston 320 is a hollow portion 500 formed along the axial direction from the point where the through hole 400 ends to the point where the compression piston 320 is connected to the compression piston spring as shown in FIGS. 1 and 4 It may include. The diameter of the hollow part 500 may be configured to be larger than the diameter of the through hole 400. Accordingly, a step may be formed by contacting the point at which the extension of the sealing guide 700 toward the displacer spring 602 ends and the through hole 400 and the hollow part 500 contact each other. It is not limited to the shape of the hollow portion 500 shown in FIG. 1 and may be configured in various shapes. Cooling efficiency can be increased by minimizing energy required for the reciprocating motion of the compression piston 320 through the hollow part 500. In addition, it is possible to prevent leakage of the operating gas through the sealing guide 700 and increase cooling efficiency by reducing the contact area between the displacer rod 100 and the compression piston 320 penetrating therethrough.

Next, based on FIGS. 4 to 5, a gap G1 between the outer circumferential surface of the displacer piston 310 and the inner circumferential surface of the first cylinder 210, and a gap G2 between the sealing guide 700 and the through hole 400 , The gap G3 between the compression piston 320 and the second cylinder 220 will be described. The above-described gaps need to be set extremely small so that the working gas does not leak when the Stirling cooler 1 runs the Stirling cycle. Therefore, each of the gaps (G1, G2, G3) can be formed to a level of 10-30㎛. Thus, the displacer piston, the compression piston, the displacer rod, and the cylinder can be configured such that the exact alignment, that is, coaxiality, is consistent. The alignment or coaxiality may be slightly twisted and inconsistent depending on the self-weight or external conditions, the spring, and the degree of processing of the connection portion of the displacer rod 100 during the reciprocating motion of the displacer piston 310 or the compression piston 320. have. If the reciprocating motion is continued in this state, wear may progress between the configurations in which the three gaps G1, G2, and G3 are formed. That is, when the displacer rod 100, the displacer piston 310, and the compression piston 320 are subjected to a significant side force, wear may proceed between the configurations in which the three gaps G1, G2, and G3 are formed. . Such wear may lead to a decrease in the cooling efficiency of the Stirling cooler (1). Therefore, precision processing and assembly may be required to match the distortion and coaxiality. As a result, manufacturing cost may increase and assembly time may be required. This could lead to a decrease in the productivity of the Stirling refrigerator.

Next, the length and bending stiffness of the displacer rod 100 will be described with reference to FIGS. 1, 6, and 7.

In general, the bending stiffness of a rod configured in the form of a cantilever is inversely proportional to three squares of the length of the rod.

If the bending stiffness of the rod is lowered, it is possible to reduce the side force caused by the misalignment of the displacer piston, the compression piston, the displacer rod, and the cylinder, or the warp of the displacer rod. In other words, due to the structure having lowered stiffness, the displacer rod 100 may have a structure capable of compensating for the above-described misalignment or warpage of the rod. 1, 6, and 7, the displacer rod 100 according to an embodiment of the present invention is directly connected to the displacer piston 310, as described above, and its outer circumferential surface is a sealing guide 700 ) May be enclosed and provided in a structure facing the through hole 400. In addition, it may be configured such that a gap of a predetermined length exists between the displacer rod 100 and the sealing guide 700. This gap may be specifically set to about 20-40 μm. Also, unlike the above embodiment, it may be configured in a state in which a gap does not exist.

Next, the diameter ratio of the sealing guide 700 and the displacer piston 310 will be described with reference to FIGS. 4 and 5. As shown in FIG. 4, the diameter D1 of the sealing guide 700 compared to the diameter D2 of the displacer piston 310 may be configured within a certain range. 5 is a table showing performance evaluation results assuming a diameter D2 of the displacer piston 310 of the Stirling refrigerator 1 according to an embodiment of the present invention is 35 mm. 5, when the diameter (D1) of the sealing guide 700 is 7 mm, that is, the length of 20% compared to the diameter (D2) of the displacer piston 310, COP (heat absorption and consumed It can be confirmed that the ratio of the work volume of the compressor) constitutes the maximum efficiency as the maximum. In addition, when the diameter D1 of the sealing guide 700 has a length of 12 mm, that is, 34% of the diameter D2 of the displacer piston 310, it can be seen that the maximum cooling power is configured. Therefore, it may be desirable that the diameter (D1) of the sealing guide 700 compared to the diameter (D2) of the displacer piston 310 constitutes about 15%-40%.

Next, the range and the length of the sealing guide 700 will be described with reference to FIGS. 1, 6 and 7. As shown in FIG. 1, a distance between the displacer piston 310 and the compression piston 320 being the farthest apart in the axial direction may be defined as a second distance L2. In addition, the compression piston 320 includes a through hole 400 formed with a predetermined length, that is, a first distance L1 along the axial direction located at the center of the compression piston 320 as shown in FIGS. 1 and 5. I can. In this case, the length L3 of the sealing guide 700 may be formed to be equal to the sum of the first distance L1 and the second distance L2. When the length L3 of the sealing guide 700 is secured, the contact area between the sealing guide 700 and the through hole 400 can be reduced, thereby increasing refrigeration efficiency due to friction reduction. In addition, leakage of the working gas into the gap between the sealing guide 700 and the through hole 400 can be effectively prevented.

8 to 15 are a display further including a compensation unit 110 disposed on the displacer rod 100 between one side connected to the displacer piston 310 and the other side connected to the displacer piston spring 602 The book 90 is shown. The compensation unit is aligned between the sealing guide 700 and the displacer rod 100, as well as the displacer piston 310, the compression piston 320, the displacer rod 100, and the cylinder 200 according to an embodiment of the present invention. It may contribute to compensate for the distortion of the displacer or the warpage of the displacer rod 100. In addition, unlike the above description, the compensation unit 110 may be disposed on one side connected to the displacer piston 310 and the other side connected to the displacer piston spring 602.

In the following description, the'axis direction' will be described based on the axis direction X shown in FIG. 3.

In addition, in the following description,'alignment' and'coaxiality' will be described based on the relationship between the displacer piston, the compression piston, the displacer rod, and the cylinder.

Next, a displacer 90 including a ball joint 111 in which the compensation unit 110 is another embodiment of the present invention will be described with reference to FIGS. 8 to 9. In order to simplify the drawing, the displacer piston spring 602 is omitted. 8 shows a perspective view of a displacer 90 to which a ball joint 111 is applied, which is another embodiment of the present invention. 9 shows a cross-sectional view of a displacer 90 to which a ball joint 111, which is another embodiment of the present invention, is applied.

The ball joint 111 may be configured to be rotatable about an axis perpendicular to an axial direction. During the reciprocating motion of the compression piston 320, the alignment may be finely distorted and the coaxiality may not coincide depending on the self-weight, external conditions, the degree of processing of the connection part of the spring, and the displacer rod 100. In this case, the ball joint 111 rotates based on an axis perpendicular to the axial direction, so that alignment misalignment or coaxiality mismatch may reduce side force generated. A plurality of ball joints 111 may be disposed on the displacer rod 100.

The ball joint 111 may be integrally formed with the displacer rod 100 as shown in FIG. 9. Also, unlike this, it may be manufactured in a separate configuration and fastened to the displacer rod 100 in the form of a screw. In addition, the ball joint 111 and the displacer rod 100 may be formed in a variety of structures that can be rigidly fastened.

Next, the applied displacer 90 including the link 112, which is another embodiment of the present invention, will be described with reference to FIGS. 10 to 11. In order to simplify the drawing, the displacer piston spring 602 is omitted. 10 is a perspective view of a displacer 90 in which the compensation unit 110 is configured with links 112, which is another embodiment of the present invention. 11 is a cross-sectional view of a displacer 90 in which the compensation unit 110 is configured as a link 112 according to another embodiment of the present invention.

The link 112 may be configured to be rotatable about an axis perpendicular to an axial direction. During the reciprocating motion of the compression piston 320, the alignment may be finely distorted and the coaxiality may not coincide depending on the self-weight, external conditions, the degree of processing of the connection part of the spring, and the displacer rod 100. In this case, the link 112 rotates based on an axis perpendicular to the axial direction, thereby reducing a side force caused by misalignment or coaxiality mismatch. A plurality of links 112 may be disposed on the displacer rod 100. When a plurality of links 112 are disposed, the rotation axis directions of each link may be different.

The link 112 may be integrally formed with the displacer rod 100 as shown in FIG. 11. Also, unlike this, it may be manufactured in a separate configuration and fastened to the displacer rod 100 in the form of a screw. In addition, the link 112 and the displacer rod 100 may be formed in a variety of structures that can be rigidly fastened.

Next, a displacer 90 including a wire 113 and a spring 114 in which the compensation unit 110, which is another embodiment of the present invention, will be described with reference to FIGS. 12 to 13. In order to simplify the drawing, the displacer piston spring 602 is omitted. 12 is a perspective view of a displacer 90 in which the compensating part 110 is composed of a wire 113 and a spring 114, which is another embodiment of the present invention. 13 is a cross-sectional view of a displacer 90 in which the compensation unit 110 is composed of a wire 113 and a spring 114, which is another embodiment of the present invention.

Part or all of the displacer rod 100 wrapped by the sealing guide 700 may be formed of a wire 113. In this case, the displacer rod 100 may be configured to have lower bending stiffness compared to the case of the embodiment disclosed in FIGS. 6 and 7. Therefore, it is possible to more easily reduce the side force generated due to misalignment or coaxiality mismatch.

In addition, when there is a risk of buckling during compression, the spring 114 may be disposed on the outer peripheral surface of the wire 113. During axial compression, the spring 114 can bear the load and reduce the possibility of buckling. The spring 114 may be composed of a leaf spring or a coil spring. In addition, any spring that can support compression in the axial direction may be composed of various types of springs.

Next, with reference to FIGS. 14 to 15, a displacer 90 in which the compensation unit 110 is made of a resin 115 according to another embodiment of the present invention will be described. In order to simplify the drawing, the displacer piston spring 602 is omitted. 14 is a perspective view of a displacer 90 in which the compensation unit 110 is made of a resin 115 according to another embodiment of the present invention. 14 is a cross-sectional view of a displacer 90 in which the compensation unit 110 is made of a resin 115 according to another embodiment of the present invention.

Part or all of the displacer rod 100 may be made of a resin having lower bending stiffness than metal. For example, in contrast to the case where the displacer rod 100 is made of SUS 304 out of stainless steel, when made of a resin such as PEEK, the bending stiffness may be formed at a level of 2%. Therefore, it is possible to more easily reduce the side force generated due to misalignment or coaxiality mismatch.

In addition, when there is a risk of buckling during compression, the above-described spring 114 may be disposed on the outer peripheral surface of the displacer rod 100. During axial compression, the spring 114 can bear the load and reduce the possibility of buckling.

In the above, specific embodiments have been illustrated and described. However, it is not limited to only one embodiment, and those of ordinary skill in the art to which the invention pertains will be able to perform various changes without departing from the gist of the technical idea of the invention described in the following claims.

Claims

case;

A cylinder disposed in the case;

A compression piston provided to reciprocate in the axial direction inside the cylinder and including a through hole;

A displacer piston disposed to be spaced apart from the compression piston in the axial direction;

A displacer rod connected to the displacer piston and extending in the axial direction to pass through the compression piston;

And a sealing guide extending in the axial direction from the displacer piston to be inserted into the through hole and surrounding a portion of the displacer rod.
The method of claim 1,

When defining the length formed in the compression piston of the through hole as a first distance,

The compression piston is a Stirling refrigerator including a hollow portion in the interior spaced by a first distance from the surface of the compression piston facing the displacer piston.
The method of claim 2,

When the displacer piston and the compression piston are defined as the second distance the most spaced apart in the axial direction,

Stirling refrigerator configured to have the same length as the sum of the first distance and the second distance.
The method of claim 1,

A Stirling refrigerator having a gap formed between the inner circumferential surface of the through hole and the outer circumferential surface of the sealing guide.
The method of claim 1,

A Stirling refrigerator consisting of 15%-40% of the diameter of the sealing guide relative to the diameter of the displacer piston.
The method of claim 1,

The displacer load,

A Stirling refrigerator further comprising a compensation unit configured to compensate for a misalignment of alignment between the displacer piston, the compression piston, the displacer rod, and the cylinder, or a warpage of the displacer rod.
The method of claim 1,

The Stirling refrigerator,

A displacer spring spaced apart from the compression piston in the axial direction and disposed on the opposite side of the displacer piston;

A coupling portion in which the displacer rod is coupled to the displacer piston or the displacer spring; Including more,

The coupling part,

A Stirling refrigerator further comprising a compensation unit configured to compensate for a misalignment of alignment between the displacer piston, the compression piston, the displacer rod, and the cylinder, or a warpage of the displacer rod.
The method according to any one of claims 6 or 7,

Stirling refrigerator comprising one or more ball joints configured to be rotatable about an axis perpendicular to the axial direction.
The method according to any one of claims 6 or 7,

Stirling refrigerator comprising one or a plurality of links configured to be rotatable about an axis perpendicular to the axial direction.
The method of claim 1,

The displacer rod is a Stirling refrigerator containing a resin.
In claim 6,

Stirling refrigerator in which the displacer rod is disposed at the center of a spring having a diameter larger than that of the displacer rod.
The method of claim 1,

The displacer rod is a Stirling refrigerator comprising a wire.
The method of claim 12,

Stirling refrigerator in which the wire is disposed at the center of a spring having a diameter larger than that of the wire.
cylinder;

A displacer piston provided to reciprocate in the axial direction inside the cylinder;

A compression piston disposed to be spaced apart from the displacer piston in the axial direction and including a through hole extending along the axial direction from a surface of the compression piston facing the displacer piston;

A displacer spring spaced apart from the compression piston in the axial direction and disposed on the opposite side of the displacer piston;

A displacer rod connected to the displacer piston and extending in the axial direction to pass through the compression piston;

And a sealing guide extending in the axial direction from the displacer piston to be inserted into the through hole and surrounding a portion of the displacer rod.
The method of claim 14,

The compression piston includes a hollow portion in the interior spaced apart from the surface of the compression piston facing the displacer piston,

Stirling refrigerator disposed so as to contact the hollow portion with the through hole.
The method of claim 15,

The through hole extends along the axial direction from a surface of the compression piston facing the displacer piston,

The extension is formed such that when the displacer piston and the compression piston are separated at a maximum distance, a point at which the extension of the sealing guide ends and a point at which a step is formed by contacting the through hole and the hollow portion are the same.
The method of claim 1,

The displacer load,

A Stirling refrigerator further comprising a compensation unit configured to compensate for a misalignment of alignment between the displacer piston, the compression piston, the displacer rod, and the cylinder, or a warpage of the displacer rod.
The method of claim 14,

A Stirling refrigerator consisting of 15%-40% of the diameter of the sealing guide relative to the diameter of the displacer piston.
The method of claim 17,

Stirling refrigerator comprising one or more ball joints configured to be rotatable about an axis perpendicular to the axial direction.
The method of claim 17,

Stirling refrigerator comprising at least one link configured to be rotatable about an axis perpendicular to the axial direction.