JP2003287304A - Stirling refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an oil seal mechanism for effectively reducing oil loss, and to improve the performance and reliability of a stirling refrigerator. <P>SOLUTION: In oil seal mechanisms 21, 22, outer surfaces of piston rods 21, 27 are sealed with a guide ring arranged on the upper part of a seal housing 54, and the inner surface of the seal housing 54 is sealed with an oil seal 63 mounted on the large diameter part 52 of the piston rod. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Stirling refrigerator, and more particularly to an oil seal mechanism for a compression piston rod and an expansion piston rod of the Stirling refrigerator.

[0002]

2. Description of the Related Art In recent years, as a refrigerating device as an alternative to CFCs for global environmental problems, and having a wider operating temperature than conventional cooling devices, therefore, cold or heat utilization equipment for business use such as freezer, refrigerator, throw-in cooler, etc. , Low temperature liquid circulator, low temperature incubator, constant temperature bath, heat shock test device, freeze dryer, temperature characteristic test device, blood / cell storage device, cold cooler, and various other cooling and heating devices The Stirling refrigerator is in the spotlight as a refrigerator that can be applied to cold heat utilization equipment, is compact, has a high coefficient of performance, and has good energy efficiency.

By the way, in a heat engine such as a Stirling refrigerator, a working gas is hermetically sealed in a housing which constitutes a main body and has a crank chamber and a motor chamber. On the other hand, the working gas flows between the compression chamber (high temperature chamber) and the expansion chamber (low temperature chamber), and the cooling heat exchanger (low temperature side heat exchanger) and the heat radiating device arranged along this flow path. The heat exchanger (high temperature side heat exchanger) exchanges heat with the cold heat refrigerant and the heat radiating refrigerant, respectively.

In the Stirling refrigerator, oil (lubrication oil) or oil mist in the crank chamber rises along the surface of the piston rod, enters the cylinder for compressing or expanding the working gas, and causes "baking up" or the like.
There is a peculiar problem, which has been a cause of lowering the performance and reliability of the Stirling refrigerator.

As a rod seal for preventing the rise of oil and mist along the outer peripheral surface of such a piston rod, an oil seal called a lip seal which is in sliding contact with the piston rod from the outside and scrapes oil is conventionally used. It was arranged between the crank chamber of the Stirling refrigerator and a non-lubricated part such as a cylinder (buffer space, compression cylinder, expansion cylinder, etc.).

Further, conventionally, as another sealing means, one end is welded to the crank chamber side housing upper surface and the other end is connected to the piston rod between the crank chamber of the Stirling refrigerator and a non-lubricated portion such as a cylinder. A means called a bellows seal utilizing a welded metal bellows has been provided.

[0007]

In the conventional rod seal, when the piston rod is laterally deflected while the oil is scraped off or the oil mist is sealed by the lip seal, a gap is generated between the lip seal and the piston rod. However, there is a problem that oil or oil mist rises from this gap and enters the cylinder side which is a non-lubricated part.

The non-lubricated parts such as the crank chamber and the cylinder are filled with working gas such as He gas at a high pressure, but the working gas directly flows between the non-lubricated parts such as the crank chamber and the cylinder. Then, the pressure of the working gas in the unlubricated portion of the cylinder or the like depends on the temperature of the crank chamber and the change of the pressure, so that the operation of the compression cylinder and the expansion cylinder becomes unstable, and the refrigerating capacity of the Stirling refrigerator is reduced. However, a lip seal alone is not sufficient as a seal against such a working gas.

Although the conventional bellows seal is excellent in sealing performance, when the Stirling refrigerator is operated at a high speed, stress is concentrated on the welding attachment point, or fatigue due to repeated stress causes a relatively easy breakage. was there.

The inventors of the present invention have examined a sealing mechanism having a structure shown in FIG. 5 as a prior art of the present invention for the prevention of lateral blurring. This is provided with a seal housing 65 between the crank chamber formed by the housing of the main body of the Stirling refrigerator, the compression cylinder, and the expansion cylinder. The seal housing 65 is slidably contacted with the outer peripheral surface of the piston rod 66. An oil seal (lip seal) 68 for performing a seal (sealing) is provided, and a guide ring 67 for guiding the piston rod is provided.

According to the preceding seal mechanism, the oil seal 6 is applied to the outer peripheral surface of the piston rod 66 from the outside.
Since the piston rod 66 is guided by the guide ring 67 while slidingly contacting 8, the lateral movement is certainly eliminated as compared with the case where only the oil seal is provided.

However, in this sealing mechanism, since the guide ring 67 and the oil seal 68 are pressed from the outside against the outer peripheral surface of the piston rod 66, all the oil rising along the piston rod 66 is pressed. Since the oil seal must work,
The sealing effect is not always sufficient.

Further, depending on the mounting condition of the guide ring, wear, etc., sideways deviation or backlash still occurs, and the problem of the gap of the oil seal which occurs during sideways deviation cannot be sufficiently solved, and it is against the working gas. The function as a gas seal is not always sufficient.

Therefore, in order to solve the above problems of the conventional oil seal or the problems of the preceding seal mechanism, the inventors have studied the novel seal mechanism by taking the following points as concrete problems. As a result of earnestly proceeding with the development, the present invention has been accomplished. (1) In order to prevent oil from entering the non-lubricated part from a gap formed in the oil seal due to the sideways displacement of the piston rod, the piston rod is reliably guided so that sideways displacement does not occur. In particular, the present invention realizes an oil seal mechanism having a structure capable of reducing the amount of oil itself that rises along the rod that should be blocked by the oil seal, by making it difficult for the oil to rise along the piston rod. (2) Oil rises along the piston rod and effectively prevents oil from entering the non-lubricated part to improve reliability and refrigerator performance, and also exhibits a sufficient gas sealing function against working gas. Thus, it is possible to prevent the adverse effect on the operation of the operating portion due to the pressure change of the crank chamber in the Stirling refrigerator, and prevent the deterioration of the refrigerating capacity. (3) Each component constituting the seal mechanism and its mounting structure are simple and easy to maintain. Especially, regarding the mounting structure of each component of the seal mechanism, there is no deviation or the like during operation, Moreover, the structure is such that it can be securely attached. (4) A structure that is resistant to damage and has a reliable structure even during long-term operation or high-speed operation such as high-speed operation, reduces the maintenance frequency, and extends the service life.

[0015]

In order to solve the above problems, the present invention provides a housing having a crank chamber, a compression cylinder and an expansion cylinder fixed to the top of the crank chamber, and a compression cylinder and an expansion cylinder inside the cylinder. A compression piston and an expansion piston that reciprocally move to compress and expand the working gas; a compression piston rod and an expansion piston rod that are interlocked with a crank in the crank chamber and have one end connected to the compression piston and the expansion piston; In a Stirling refrigerator comprising an oil seal mechanism for sealing a gap between each of the compression piston rod and the expansion piston rod and the top opening of the crank chamber, the oil seal mechanism for the compression piston rod and the expansion piston rod is , Each equipped with a seal housing, Inside the housing, there are provided guide rings that are elastically urged by an O-ring to guide the compression piston rod and the expansion piston rod, respectively. There is provided a Stirling refrigerator having an outer surface of the large diameter portion and an oil seal which is in sliding contact with the inner surface of the seal housing.

In order to solve the above problems, the present invention interlocks with a housing having a crank chamber, a cylinder fixed to the top of the crank chamber, a piston reciprocating in the cylinder, and a crank in the crank chamber. Then, in a Stirling refrigerator comprising a piston rod whose one end is connected to the piston, and an oil seal mechanism for sealing a gap between the piston rod and the top opening of the crank chamber, the oil seal mechanism is A seal housing is provided, and a guide ring that is elastically biased by an O-ring and guides the piston rod is provided inside the seal housing, and the piston rod has a large diameter portion, An oil seal, which is in sliding contact with the inner surface of the seal housing, is mounted on the outer surface of the large diameter portion. To provide a Stirling refrigerator.

The large-diameter portion may be formed integrally with or separately from the piston rod.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on examples with reference to the drawings. 1 to 3 are diagrams illustrating a Stirling refrigerator to which the present invention is applied, and FIG. 1 is a front view illustrating the entire configuration of the Stirling refrigerator 1. FIG. 2 is a diagram for explaining a main part of the Stirling refrigerator 1, and FIG. 3 is a diagram partially showing a right side view of a cross section.

The housing 2 made of cast metal of the Stirling refrigerator 1 has a motor chamber 4 and a crank chamber 5 which are kept in a sealed state and communicate with each other through a partition wall 3.
Have and. A motor 6 capable of rotating in the normal and reverse directions is arranged in the motor chamber 4, and the crank chamber 5 includes a crank shaft 7, connecting rods 8 and 9 which are rotationally driven by the motor 6, cross guide heads 10 and 11, and the like. A drive mechanism is provided.

Two crank parts 1 of the crankshaft 7
Reference numerals 2 and 13 are formed with a phase difference so that the crank portion 13 moves ahead of the crank portion 12 when the motor 6 rotates in the normal direction. As this phase difference, a phase difference of about 90 degrees is generally adopted. Connecting rods 8 and 9 are attached to the crank portions 12 and 13, and cross guide heads 10 and 11 are attached to the connecting rods 8 and 9.

A cylinder block 15 is attached to the upper portion of the crank chamber 5 of the housing 2 with a bolt 16 via a seat portion 14. The cylinder block 15 forms a compression cylinder 17 and a part (lower part) of the expansion cylinder 18.

The space above the compression piston 19 (compression space) that reciprocates in the compression cylinder 17 is the high temperature chamber 20,
In this, the working gas is compressed and becomes high temperature. The compression piston rod 21 connects the compression piston 19 and the cross guide head 10, and is provided so as to extend from the crank chamber 5 to the compression cylinder 17 through the top opening of the crank chamber 5. An oil seal mechanism 22 is attached between the top opening 55 of the crank chamber 5 and the compression cylinder 17, and the compression piston rod 21 and the top opening of the crank chamber 5 (correctly, the inner peripheral edge of the opening) 55 are connected. The gap is sealed to prevent oil from rising from the crank chamber 5.

On the other hand, the expansion cylinder 18 has a lower portion composed of the cylinder block 15 as described above and an upper portion thereof.
It is composed of an inner cylinder 23 of a heat radiating heat exchanger 29 described later and an inner cylinder 24 of a cooling heat exchanger. An upper space (expansion space) of the piston 25 that slides back and forth in the expansion cylinder 18 is a low temperature chamber 26, in which the working gas expands and becomes a low temperature.

The expansion piston rod 27 connects the expansion piston 25 and the cross guide head 11 and is provided so as to extend from the crank chamber 5 into the expansion cylinder 18 through the top opening 55 of the crank chamber 5. An oil seal mechanism 28 is provided between the crank chamber 5 and the expansion cylinder 18.
Is attached to seal the gap between the expansion piston rod 21 and the top opening portion (correctly, the inner peripheral edge of the opening portion) 55 of the crank chamber 5 to prevent oil from rising from the crank chamber 5. The expansion piston 25 is 90
It moves ahead by the phase of degrees.

A heat-radiating heat exchanger (high-temperature-side heat exchanger) 29, a regenerator 30, and a cooling heat-exchanger (low-temperature-side heat exchanger) 31 communicate with each other and are annularly arranged so as to surround the expansion cylinder 18. It is set up. A manifold (flow path for working gas) 32 is formed around the lower end of the heat radiating heat exchanger 29 and around the expansion cylinder 18.

At the upper end of the compression cylinder 17,
Communication hole 33 for communicating the high greenhouse 20 and the manifold 32
Are formed. The high greenhouse 20 and the low temperature chamber 26 are configured to sequentially communicate with each other through the communication hole 33, the manifold 32, the heat radiating heat exchanger 29, the regenerator 30, and the cooling heat exchanger 31.

The cylinder block 15 has a heat radiating heat exchange housing 34 on its upper part. A heat exchanger tube 37 is fitted between the heat radiating heat exchange housing 34 and the inner cylinder 23, and the heat radiating heat exchanger (high temperature side heat exchanger) 2
9 is composed. The heat exchanger tube 37 has, on its inner surface,
It has a narrow groove 35 that forms a flow path of the working gas, and has a radiation fin 36 on the outer surface.

The working gas passes through the narrow groove 35, and the cooling water flows through the heat dissipation path 38 between the heat dissipation housing for heat dissipation 34 and the heat dissipation fins 36, whereby the heat of the working gas is dissipated to the cooling water. A lid plate 39 is watertightly fixed to both left and right side surfaces of the cylinder block 15, and a cooling water passage 40 is formed between the lid plate 39 and the cylinder block 15. The cooling water passage 40 communicates with the inlet 41 and the heat dissipation passage 38.
And is formed so as to surround the compression cylinder 17 and the expansion cylinder 18.

A cooling water inflow port 42 is provided in the heat radiation path 38, an outflow port 43 is provided in the cooling water path 40, and the inflow port 40 and the outflow port 43 are not shown in the drawing, but are not shown in the drawing. It is connected to an air-cooled radiator (radiator) having a cooling fan via a water circulation pump.

The lower part of the inner cylinder 24 is fitted with the inner cylinder 23 to form a part of the expansion cylinder 18. A cooling heat exchange housing 44 is arranged on the upper outer peripheral side of the inner cylinder 24. It is detachably fixed to the cylinder block 15. The heat exchange housing 44 for cooling has a plurality of narrow grooves 45 on its inner surface, is fitted with the inner cylinder 24 to form a working gas passage 46, and has cooling fins 47 on its outer surface.
This constitutes the cooling heat exchanger (low temperature side heat exchanger) 31.

This cooling heat exchanger 31 cools the cold heat refrigerant of the cold heat utilizing equipment which utilizes the cold heat of the Stirling refrigerator of the present invention. Air, water, alcohol, HFE, PFC or the like is used as the cold heat refrigerant.

A regenerator 30 made of a cold storage material such as a metal mesh is arranged in an annular space between the inner cylinder 24 and the cooling heat exchange housing 44.

Oil seal mechanism 28 and expansion piston 25
Space between the oil seal mechanism 22 and the compression piston 1
The same applies to the space between 9 and 9) is called the buffer space (buffer chamber) 48. The buffer space 48 is
The pipe 49 is connected to the buffer tank 51, and the buffer tank 51 is connected to the crank chamber 5 (or the motor chamber 4) of the housing 2 by the pipe 50.

The present invention has the above-mentioned structure, and particularly, the compression piston rod 21 and the expansion piston rod 2
7 is characterized by the configuration of the oil seal mechanisms 22 and 28 for 7. In the Stirling refrigerator, the state where the oil seal mechanisms 22 and 28 are attached is shown in FIG.

FIG. 4 shows an oil seal mechanism 2 according to the present invention.
FIG. 4A is a diagram for explaining the details of 2 and 28 in FIG.
FIG. 4 is a vertical cross-sectional view taken along the axial center of the piston rods 21, 27 of the oil seal mechanisms 22, 28 according to the present invention, showing the configuration of the oil seal mechanism 22 in FIG. 4 (b) is a sectional view taken along line AA of FIG. 4 (a).

By the way, the oil seal mechanism 22 and the oil seal mechanism 28 have the same construction, and the mounting arrangement is such that the oil seal mechanism 22 is mounted on the compression cylinder 17 side, whereas the oil seal mechanism 22 is mounted on the compression cylinder 17 side. The mechanism 28 is different in that it is attached to the expansion cylinder 18 side, but the attachment structure is the same. Therefore, the structure of the oil seal mechanism 22 and the oil seal mechanism 28 and the mounting structure thereof will be described in common in FIG. Oil seal mechanism 22 and oil seal mechanism 28
The reference numerals relating to the configuration are also described.

2 and 4 (a), the oil seal mechanisms 22 and 28 have a substantially cylindrical seal housing 54 having a large diameter portion 52 and a small diameter portion 53. The large diameter portion 52 of the seal housing 54 is fitted and placed in the opening 55 of the housing 2 of the Stirling refrigerator 1 corresponding to the compression cylinder 17 and the expansion cylinder 18, and the seat portion 14 is placed from above. Then, this is screwed to the housing 2 with the bolt 16. As a result, the seal housing 5
The large-diameter portion 52 of No. 4 is fastened and the seal housing 54
Are mounted in the compression cylinder 17 and the expansion cylinder 18.

A shelf wall 56 is formed above the small diameter portion 53 of the seal housing 54, and a piston rod opening 57 is formed at the center of the shelf wall 56. This opening 5
A compression piston rod 21 and an expansion piston rod 27 (referred to as “piston rods 21 and 27”) are inserted through 7.

A guide ring 58 is mounted on the shelf wall 56 so as to fit the piston rods 21, 27, and an O-ring 59 is mounted on the outer side of the guide ring 58. The guide ring 58 and the O-ring 59 are fastened by mounting an annular lid plate 60 from above and screwing a screw 61 onto the upper surface of the small diameter portion 53.

The piston rods 21 and 27 have a large diameter portion 62.
(It may be formed by fixing an annular member.). The large diameter portion 62 has an outer diameter smaller than the inner diameter of the seal housing 54 and is movable inside the seal housing 54. An oil seal 63 such as a lip seal is attached to the outer peripheral surface of the large diameter portion 62. The oil seal 63 slidably contacts the inner surface of the seal housing 54 and seals the gap between the piston rods 21 and 27 and the seal housing 54.

As described above, in the oil seal mechanisms 21 and 22 of the Stirling refrigerator according to the present invention, the guide ring 58 provided on the upper part of the seal housing 54 seals the outer surfaces of the piston rods 21 and 27 and the pistons. Oil seal 63 attached to the large diameter portion 52 of the rod
Seals against the inner surface of the seal housing 54
It is a configuration for performing.

(Operation) Next, the operation of the Stirling refrigerator of the above embodiment of the present invention will be described. The motor 6 rotates the crankshaft 7 in the forward direction, and the crank portions 12 and 13 in the crank chamber 5 rotate 90 degrees out of phase.
The connecting rod 8 connected to the crank portions 12 and 13,
The compression piston 19 and the expansion piston 25 reciprocate through the cross guide heads 10 and 11, the compression piston rod 21, and the expansion piston rod 27 with a phase difference of 90 degrees.

While the expansion piston 25 moves 90 degrees ahead and moves slowly near the top dead center, the compression piston 19 moves rapidly near the middle toward the top dead center to compress the working gas. The compressed working gas flows into the narrow groove 35 of the heat radiating heat exchanger 29 through the communication hole 33 and the manifold 32, and radiates heat to the cooling water flowing through the heat radiating passage 38. Further, the working gas is cooled by the cold heat stored in the regenerator 30, passes through the narrow groove 45, and flows into the low temperature chamber 26 (expansion space).

When the compression piston 19 is slowly moving near the top dead center, the expansion piston 25 rapidly moves toward the bottom dead center, and the working gas flowing into the low temperature chamber 26 (expansion space) rapidly expands. Then cold heat is generated. As a result, the head portion (called a cold head) 48 including the heat exchanger 31 for cooling is cooled to a low temperature.

Then, in the cooling heat exchanger 31, the cold heat refrigerant for the equipment utilizing cold heat, which is in contact with the cooling fins 47, is cooled. When the expansion piston 25 moves from the bottom dead center to the top dead center, the compression piston 19 moves from the intermediate position to the bottom dead center, and the working gas flows from the low temperature chamber 26 through the narrow groove 45 of the cooling heat exchanger to the regenerator. Cold heat flowing into the working gas 30 and contained in the working gas is stored in the regenerator 30. The cold heat stored in the regenerator 30 is transferred from the high temperature chamber 20 to the heat radiating heat exchanger 29 as described above.
The working gas sent through is reused for cooling again.

Then, the cold heat refrigerant cooled in the cooling heat exchanger is sent from the outflow pipe 64 to various cold heat utilizing devices and used for cooling. For example, the cold heat refrigerant is sent to a cold heat refrigerant pipe in a cold heat utilization apparatus such as a freezer, and performs a freezing or cooling action in the cold heat utilization apparatus. Then, the cold heat utilization equipment circulates back to the cooling heat exchanger 31 through the inflow pipe 65 and is cooled again.

The cooling water sent from the radiator (radiator) flows into the heat radiating heat exchanger 38 through the inlet 42, passes through the heat radiating passage 38, and cools the working gas. Further, this cooling water flows into the cooling water passage 40 and flows around the compression cylinder 17 and the expansion cylinder 18. As a result, the compression cylinder 17 and the expansion cylinder 18 formed inside the cylinder block 15 are cooled from the surroundings. After that, the cooling water flows out from the outflow port 43, is cooled by the cooling fan in the radiator, and is circulated again to the heat radiation heat exchanger 29.

The buffer tank 51 has a buffer space 48.
The housing 2 has a uniform pressure, absorbs pressure fluctuations in the buffer space 48, and absorbs pressure fluctuations in the housing 2 so as not to affect the buffer space.

When the piston rods 21 and 27 move up and down during operation of the Stirling refrigerator 1, the piston rod 2
1, 27 move up and down through the oil seal mechanisms 21 and 22. Then, the piston rods 21 and 27 slide with respect to the guide ring 58 provided on the upper part of the seal housing 54, and the guide ring 58 moves the piston rods 21 and 27.
Along with guiding 27, oil (oil mist) rising along the surfaces of the piston rods 21, 27 and oil mist are sealed so as to prevent the rising.

The oil seal 63 attached to the large diameter portion 62 of the piston rods 21, 27 slides on the inner surface of the seal housing 54, and the piston rods 21, 2,
Sealing is performed so as to prevent oil and oil mist rising from the gap between 7 and the seal housing 54.

In the Stirling refrigerator 1, as described above,
The piston rods 21 and 27 rise along the surfaces of the piston rods 21 and 27, and the buffer space 48, the compression cylinder 17, and the expansion cylinder 18
The so-called "oil rise" that gets inside becomes a problem.
In the seal mechanisms 22 and 28 according to the present invention, the crank chamber 5
Even if the oil rises along the surfaces of the piston rods 21 and 27 from the large diameter portion 5 of the piston rods 21 and 27,
Since there is 2, it is necessary to move in the gap direction (outward from the axial center) between the seal housing 54 and the large diameter portion 52 of the rod along the bottom surface 64 thereof in order for the oil to further rise. The rise is blocked or difficult.

Further, the oil seal mechanism 22 according to the present invention,
In 28, the oil seal 63 has a structure in which the oil seal 63 is in sliding contact with the inner surface of the seal housing 54.
Since the structure is not in direct sliding contact with the engine, even if the piston rods 21 and 27 are slightly laterally displaced during operation, as in the prior example, oil, oil, and oil are discharged from the gap between the oil seal 68 and the piston rod 66. The phenomenon that the mist passes through does not occur.

In the seal mechanism according to the present invention, the piston rods 21 and 27 are laterally shaken to cause the piston rods 21 and 27 to move sideways.
It is conceivable that a gap may occur between the oil seal 63 of the large diameter portion 52 of 27 and the inner surface of the small diameter portion 53 of the seal housing 54.

However, in the oil seal mechanisms 22 and 28 according to the present invention, the small diameter portion 53 of the seal housing 54 is used.
On the shelf wall 56 of the guide ring 58, a guide ring 58 that is urged to be elastically pressed by the O-ring 59 against the outer surfaces of the piston rods 21 and 27 is provided.
Prevents lateral displacement of the piston rods 21, 27, and a gap is unlikely to be formed between the oil seal 63 and the inner surface of the small diameter portion 53 of the seal housing 54 due to the lateral displacement.

Further, since the guide ring 58 mounted on the upper portion of the small diameter portion 53 of the seal housing 54 is biased by the O-ring 59 from the outside toward the piston rod, oil such as lip seal is used. The seal 63 not only prevents oil and oil mist that cannot be captured by the seal 63 from entering the unlubricated portion, but also functions as a gas seal that blocks the flow of the working gas between the crank chamber 5 and the unlubricated portion such as the cylinder. Even if there is a change in the pressure of the working gas due to a change in the temperature in the crank chamber 5, etc., it is prevented from affecting the non-lubricated portion such as the cylinder, so that the refrigerating capacity of the Stirling refrigerator 1 is not reduced.

The guide ring 58, together with the O-ring 59 on the outside thereof, is mounted on the shelf wall 56, and a ring-shaped cover plate 60 is screwed from above onto the upper surface of the small diameter portion 53 to simplify the operation. Can be attached to. As described above, the structure for attaching the guide ring 58 and the O-ring 59 is also simple, so that the manufacturing, maintenance, and the like thereof are easy.

The embodiments of the present invention have been described above based on the examples, but the present invention is not limited to the above examples and various modifications can be made within the scope of the technical matters described in the claims. It goes without saying that there are examples.

[0058]

As described above, the present invention has the following effects. (1) Since the guide ring provided on the upper part of the seal housing seals the outer surface of the piston rod and the oil seal mounted on the large diameter part of the piston rod seals the inner surface of the seal housing, It is possible to make it difficult for the oil to rise along the line and reduce the amount of oil that the rod seal should prevent. This improves the performance and reliability of the Stirling refrigerator and reduces the frequency and cost of maintenance.

(2) In addition to the oil seal, a guide ring provided with elasticity by an O-ring is provided to guide and seal the piston rod, thereby preventing lateral displacement of the piston rod and providing a large diameter portion of the piston rod. A gap is not formed between the mounted oil seal and the inner surface of the seal housing, and oil is effectively prevented from rising.

(3) By providing the O-ring with the guide ring to which the elastic force is applied in the direction of pressing the piston rod from the outside, sufficient sealing performance can be exhibited even against the working gas, and the Stirling refrigerator Improve the refrigeration capacity.

(4) Since each component constituting the seal mechanism and its mounting structure are simple, it is easy to manufacture and maintain. In addition, even during long-term operation or severe operation such as high-speed operation, it is less likely to be damaged and reliability is improved.
The maintenance frequency is also reduced and the service life can be extended.

[Brief description of drawings]

FIG. 1 is a front view for explaining the overall configuration of a Stirling refrigerator according to the present invention.

FIG. 2 is a diagram showing a main part of the Stirling refrigerator of FIG.

FIG. 3 is a right side partially cutaway front view illustrating a Stirling refrigerator according to the present invention.

FIG. 4 is a diagram illustrating a seal mechanism of a Stirling refrigerator according to the present invention.

FIG. 5 is a diagram illustrating a prior art of a seal mechanism of a Stirling refrigerator according to the present invention.

[Explanation of symbols]

1 Stirling Refrigerator 2 Housing 3 Partition Wall 4 Motor Chamber 5 Crank Chamber 6 Motor 7 Crankshaft 8, 9 Connecting Rod 10, 11 Cross Guide Head 12, 13 Crank Part 14 Seat 15 Cylinder Block 16 Bolt 17 Compression Cylinder 18 Expansion Cylinder 19 Compression piston 20 upper space (compression space) high temperature chamber 21 compression piston rod 22 compression piston rod oil seal mechanism 23 inner cylinder 24 cooling heat exchanger inner cylinder 25 expansion cylinder 18 reciprocally sliding piston 26 upper space ( Expansion space is low temperature chamber 27 Expansion piston rod 28 Oil seal mechanism of expansion piston rod 29 Heat dissipation heat exchanger (high temperature side heat exchanger) 30 Regenerator 31 Cooling heat exchanger (low temperature side heat exchanger) 32 Manifold ( Working gas flow path) 33 Communication hole 34 Heat dissipation Heat exchange housing 35 Thin groove for working gas flow passage on the inner surface of heat exchanger tube 36 Radiating fins 37 Heat exchanger tube 38 Radiating heat exchange housing Radiating path 39 with heat radiating fins Cover plate 40 Cooling water channel 41 Inlet 42 Cooling Water Inlet 43 to Heat Dissipation Path 38 Outlet 44 of Cooling Water Path 40 Cooling Heat Exchange Housing 45 Plural Small Grooves on Inner Surface of Cooling Heat Exchange Housing 44 Working Gas Flow Path 47 Cooling Fin 48 Buffer Space (Buffer Space) Chamber) 49 pipe 51 buffer tank 52 large diameter portion 53 small diameter portion 54, 66 seal housing 55 housing opening 56 shelf wall 57 piston rod opening 58, 67 guide ring 59 O-ring 60 cover plate 61 screw 62 piston rod Large diameter part 63, 68 Oil seal 64 Bottom face of large diameter part of piston rod 66 Piston rod

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takehiro Nishikawa             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. (72) Inventor Hideyuki Inoue             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. (72) Inventor Takashi Atomic             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. (72) Inventor Shinya Itabashi             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. (72) Inventor Tetsuya Kato             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd.

Claims (3)

[Claims] 1. A housing having a crank chamber, a compression cylinder and an expansion cylinder fixed to the top of the crank chamber, a compression piston that reciprocates in the compression cylinder and the expansion cylinder, and compresses and expands a working gas, An expansion piston, a compression piston rod and an expansion piston rod which are interlocked with a crank in the crank chamber and have one ends connected to the compression piston and the expansion piston, the compression piston rod and the expansion piston rod, and the top of the crank chamber. In a Stirling refrigerator comprising an oil seal mechanism that seals a gap between the opening and the opening, the oil seal mechanisms for the compression piston rod and the expansion piston rod each include a seal housing, and inside the seal housing. Is elastically urged by the O-ring Guide rings for guiding the compression piston rod and the expansion piston rod respectively are provided, the compression piston rod and the expansion piston rod each have a large diameter portion, and an outer surface of the large diameter portion of the seal housing A Stirling refrigerator, comprising an oil seal that is in sliding contact with the inner surface. 2. A housing having a crank chamber, a cylinder fixed to the top of the crank chamber, a piston reciprocating in the cylinder, and a crank in the crank chamber, and one end of which is connected to the piston. A Stirling refrigerator comprising a piston rod, and an oil seal mechanism for sealing a gap between the piston rod and the top opening of the crank chamber, wherein the oil seal mechanism includes a seal housing, A guide ring that is elastically biased by an O-ring and guides the piston rod is provided inside the housing. The piston rod has a large diameter portion, and the seal is provided on the outer surface of the large diameter portion. A Stirling refrigerator, comprising an oil seal that is in sliding contact with the inner surface of the housing. 3. The Stirling refrigerator according to claim 1 or 2, wherein the large-diameter portion is formed integrally with or separately from the piston rod.