JP2815030B2 - Reverse Stirling cycle refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a reverse Stirling cycle refrigerator used for generating cryogenic temperatures.

[0002]

2. Description of the Related Art FIG. 2 is a sectional view showing an example of the structure of a conventional reverse Stirling cycle refrigerator. Reference numeral 1 denotes a working gas compressor, which includes a compression cylinder 2 and a compression piston 3 which can reciprocate in the compression cylinder 2, and a compression space 4 is formed at one end. A cylindrical inner yoke 5 and a cylindrical outer yoke 6 are provided on the outer circumference of the compression cylinder 2, a cylindrical permanent magnet 7 is provided at one end between them, and a cylindrical air gap is provided at the other end. 8 is formed, and a magnetic field is formed in the gap 8. A cylindrical movable coil 10 that reciprocates in the axial direction is provided in the gap 8. The inner yoke 5, the outer yoke 6, and the permanent magnet 7 constitute a field pole 9, and the field pole 9 and the movable coil 10 constitute a linear drive motor 11. The movable coil 10 and the compression piston 3 are connected by a connecting body 12, and the connected member is supported by a support spring 13. These compression cylinder 2, compression piston 3, linear drive motor 11, connecting body 12, and support spring 13
The working gas is sealed and housed in a sealed container 15 in which the working gas buffer space 14 is left. The movable coil 10 is connected to an external power supply via a connection lead 16 and a sealed terminal 17.

A working gas inflator 18 is an expansion cylinder 1.
9 and a displacer 22 that can reciprocate in the expansion cylinder 19. One end of the expansion cylinder 19 is hermetically sealed by the low temperature section 20 to form an expansion space 21. The displacer 2 is sandwiched between the expansion spaces 21.
2, and the displacer 22 includes a support spring 24.
Supported by The displacer 22 has therein a regenerator 2 made of, for example, a stainless steel wire mesh.
3 is provided, one end of which opens into the expansion space 21 and the other end opens into the space 26 in the holder 25.

[0004] The compression space 4 of the compression cylinder 2 of the compressor 1 and the expansion space 21 of the expansion cylinder 19 of the expander 18 are the space 26 in the regenerator 23 of the displacer 22 and the holder 25.
Through a connecting pipe 28 provided with a cooling fin 27.

A drive motor 1 in which the compression piston 3 has a linear shape
1 reciprocates in the compression cylinder 2 when the flow of the working gas generated by the reciprocation passes through the regenerator 23 in the displacer 22, the force generated by the fluid resistance causes the displacer 22 to expand the expansion cylinder 1.
9 reciprocate. A vibration system is constituted by the mass of the displacer 22, the fluid resistance of the regenerator 23, and the support spring 24. By appropriately selecting the reciprocating cycle of the compression piston 3, the displacer 22 and the compression piston 3 are different from each other. Reciprocate synchronously with the phase. When the compression piston 3 and the displacer 22 reciprocate synchronously with mutually different phases, the working medium alternately compresses and expands, generating a low temperature in the expansion space 21 of the expansion cylinder 19. This low temperature is stored in the regenerator 23, and a constant low temperature is formed in the low temperature section 20 in contact with the expansion space 21.

[0006]

In the above-described reverse Stirling cycle refrigerator, in order to increase the output of the drive motor, the gap length of the field pole is made as short as possible, and the movable coil is filled with the size of this gap. And Therefore, the distance between the movable coil and the magnetic pole of the field pole is very small, for example, about several hundred microns. Therefore, as shown in FIG. 2, a space 29 or a space 30 is formed by the compression piston 3, the compression cylinder 2, the field pole 9, the movable coil 10, and the connecting body 12 of the movable coil 10 and the expansion piston 3, and these spaces are movable. A very small gap between the coil 10 and the magnetic pole of the field pole 9 communicates with the working gas buffer space 14.

Therefore, when the member consisting of the compression piston 3, the movable coil 10 and the connecting body 12 reciprocates, the working gas in the spaces 29, 30 is transferred to the buffer space 14 via a very small gap. , Compression work occurs due to fluid resistance when moving between the spaces 29 and 30 and the buffer space 14. This compression work increases the input of the drive motor and reduces the efficiency of the refrigerator.

An object of the present invention is to provide a compression piston, a compression cylinder, a field pole, a movable coil, and a coupling of a movable coil and a compression piston when a member including a compression piston, a movable coil, and a connected body thereof reciprocates. The object of the present invention is to prevent the compression work from being caused by the movement of the working gas between the space formed and the buffer space for the working gas.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention relates to an expansion cylinder having one end hermetically sealed by a low-temperature part for cooling an object to be cooled and forming an expansion space for working gas in the body. An expander comprising a displacer which is disposed with respect to the expansion cylinder with the expansion space interposed therebetween and which can reciprocate in the expansion cylinder; and a compression cylinder having one end hermetically sealed to form a working gas compression space in the body. When,
A compression piston disposed with respect to the compression cylinder with the compression space interposed therebetween and reciprocable in the compression cylinder; a cylindrical inner yoke and a cylindrical outer yoke provided on the outer periphery of the compression cylinder; A field pole comprising a cylindrical permanent magnet provided at one end and having a gap formed at the other end between the inner yoke and the outer yoke; and a reciprocally driven axially within the gap of the field pole. The compression cylinder, the compression piston, and the linear drive motor are filled with a working gas and a buffer space for the working gas. And a compressor housed in a closed container having the above-mentioned structure. In a reverse Stirling cycle refrigerator connected by a pipe, a space formed by the compression piston, the compression cylinder, the field pole, the movable coil, and a connected body of the movable coil and the compression piston and a buffer space of the working gas are provided. A communication hole is provided in the inner yoke.

[0010]

In the reverse Stirling cycle refrigerator according to the present invention, the inner space between the space formed by the compression piston, the compression cylinder, the field pole, the movable coil, and the connected body of the movable coil and the compression piston and the working gas buffer space. Since the communication hole is provided in the yoke, when the member consisting of the compression piston, the movable coil and the connecting body thereof reciprocates, the working gas in the space moves through the communication hole with almost no fluid resistance. I do. Therefore, no compression work is caused by the movement of the working gas.

[0011]

FIG. 1 is a cross-sectional view showing the structure of one embodiment of the reverse Stirling cycle refrigerator of the present invention. The reverse Stirling cycle refrigerator of the present invention shown in FIG. The difference from the refrigerator is that the expansion piston 3, the expansion cylinder 2, the field pole 9, the movable coil 10, the space 29 or 30 formed by the connecting body 12 of the movable coil 10 and the expansion piston 3, the working gas buffer space 14, and the like. Between the communication holes 31, 32 or 33
Is provided. The communication hole 31 is provided in the connection body 12 between the movable coil 10 and the expansion piston 3, and
9 directly communicates with the working gas buffer space 14. The communication hole 32 is provided in the outer yoke 6 and directly communicates the space 30 with the working gas buffer space 14. The communication hole 33 is provided in the inner yoke 5, communicates the space 29 and the space 30, and communicates these spaces with the buffer space 14 via the communication holes 31 or 31, thereby further improving the communication effect.

When the member consisting of the compression piston 3, the movable coil 10 and the connecting body 12 reciprocates, the working gas in the spaces 29, 30 flows through the communication holes 31,
It travels through 32 or 33 with little fluid resistance. Therefore, no compression work is caused by the movement of the working gas.

[0013]

According to the present invention, an expansion cylinder having one end hermetically sealed by a low-temperature part for cooling an object to be cooled and forming an expansion space for a working gas in the body, and the expansion space is formed with respect to the expansion cylinder. An expander comprising a displacer which is interposed therebetween and which can reciprocate in the expansion cylinder; a compression cylinder having one end hermetically sealed to form a compression space for working gas in the body; and a compression space for the compression cylinder. , A compression piston that can reciprocate in the compression cylinder, a cylindrical inner yoke and a cylindrical outer yoke provided on the outer periphery of the compression cylinder, and a cylindrical shape provided at one end between them. And a field pole having a gap formed at the other end between the inner yoke and the outer yoke, and reciprocatingly driven in the gap between the field poles in the axial direction. The compression cylinder, the compression piston, and the linear drive motor have a working gas filled therein and leave a buffer space for the working gas. An inverted Stirling cycle refrigerator having a compressor housed in a closed container, wherein an expansion space of an expansion cylinder of the expander is connected to a compression space of a compression cylinder of the compressor by a connecting pipe through a displacer. A communication hole is provided in the inner yoke between the space formed by the compression cylinder, the movable coil, the field pole, the connecting body of the movable coil and the compression piston, and the buffer space for the working gas. When the member composed of the movable coil and these connected bodies reciprocates,
The working gas in the space moves through the communication hole with almost no fluid resistance, so that no compression work occurs and the efficiency of the refrigerator is remarkably improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the structure of one embodiment of a reverse Stirling cycle refrigerator according to the present invention.

FIG. 2 is a sectional view showing an example of the structure of a conventional reverse Stirling cycle refrigerator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Compression cylinder 3 Compression piston 4 Compression space 5 Inner yoke 6 Outer yoke 7 Permanent magnet 8 Air gap 9 Field pole 10 Moving coil 11 Linear drive motor 12 Coupled body 14 Buffer space (of working gas) 15 Closed vessel 18 Inflator 19 Expansion cylinder 20 Low temperature section 21 Expansion space 22 Displacer 28 Connection pipe 29 Space 30 Space 31 Communication hole 32 Communication hole 33 Communication hole

Claims (1)

(57) [Claims] 1. An expansion cylinder having one end hermetically sealed by a low-temperature part for cooling an object to be cooled to form an expansion space for a working gas in a body, and an expansion cylinder disposed between the expansion cylinder and the expansion space. An expander comprising a displacer which can reciprocate in the cylinder; a compression cylinder having one end hermetically sealed to form a compression space for working gas in the body; and a compression cylinder disposed with the compression space interposed therebetween. The compression piston includes a compression piston that can reciprocate in the compression cylinder, a cylindrical inner yoke and a cylindrical outer yoke provided on the outer periphery of the compression cylinder, and a cylindrical permanent magnet provided at one end between them. A field pole having a gap formed at the other end between the inner yoke and the outer yoke and reciprocally driven in the axial direction in the gap between the field poles and connected to the compression piston by a connector. The compression cylinder, the compression piston, and the linear drive motor are composed of a moving coil and a linear drive motor. The compression cylinder, the compression piston, and the linear drive motor are housed in a sealed container in which a working gas is sealed and a buffer space for the working gas is left. An expansion space of an expansion cylinder of the expander is connected to a compression space of a compression cylinder of the compressor through a displacer by a connecting pipe, wherein the compression piston, the compression cylinder, and the field pole are connected. An inverted Stirling cycle refrigerator in which a communication hole is provided between a space formed by a movable coil, a connected body of a movable coil and a compression piston, and a buffer space for the working gas, wherein the communication hole is an inner yoke. A reverse Stirling cycle refrigerator provided in a refrigerator.