JP2000186619A - Stirling heat engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent oil exhaustion, and also to prevent a harmful effect on an oil sealing bellows cause by pressure rise accompanied by temperature rise in a crank chamber. SOLUTION: Oil sealing bellows 53, 58 are arranged among a space in a housing 23, a compression cylinder 45 and an expansion cylinder 46 and a buffer tank 59 equipped with a pressure regulating bellows 61 is arranged between spaces 69, 70 on the back surface sides of a compression piston 48 and an expansion piston 55 and the space in the housing 23. Thereby, pressure rise in the housing 23 and pressure fluctuation in the spaces 69, 70 can be absorbed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Stirling refrigerating machine which can be used for freezing and cooling in all industrial fields such as food distribution, environmental testing, medical care, biotechnology, semiconductor manufacturing, and home appliances. .

[0002]

2. Description of the Related Art In recent years, as a refrigeration system that substitutes CFCs for global environmental problems, the operating temperature of the refrigeration system is wider than that of conventional refrigeration systems. Including
Low-temperature liquid circulators, low-temperature thermostats, constant-temperature baths, heat shock test equipment, freeze dryers, temperature characteristic test equipment, blood / cell storage devices, cold coolers, and various other types of cold heat equipment such as cooling equipment The Stirling refrigerator has been spotlighted as a refrigerator that is applicable, compact, has a high coefficient of performance, and has good energy efficiency.

FIG. 1 is a schematic view showing the entire structure of a Stirling refrigerator 1, in which a crank portion 5 of a crankshaft 4 operated by a motor 3 in a housing 2 is provided.
A compression piston rod 9 and an expansion piston rod 10 are connected to 6 via cross guide heads 7 and 8, respectively. Through these compression piston rod 9 and expansion piston rod 10, compression piston 11 and expansion piston 12
Reciprocate in the compression cylinder 13 and the expansion cylinder 14 with a phase difference, thereby compressing and expanding the working gas, and the high temperature chamber (compression chamber) 15 of the compression cylinder 13 and the low temperature chamber (expansion chamber) of the expansion cylinder 14. ) And a cooling heat exchanger (low-temperature side heat exchanger) 19 disposed between the heat-radiating heat exchanger (high-temperature side heat exchanger) 18 and the cooling-use heat exchanger (low-temperature side heat exchanger) 19, respectively. And the heat exchange between the cold gas and the working gas is performed.

However, there is a problem that oil and oil mist rise from the crank chamber along the piston rods 9 and 10, that is, so-called oil rise. When the oil or oil mist enters the compression cylinder or the expansion cylinder, the oil rise adheres to the inner surface of the cylinder, and is carbonized by heat to significantly reduce the performance and durability of the Stirling refrigerator. Conventionally, in order to solve the problem of oil rising, the compression piston rod 9 and the expansion piston rod 10 are sealed by oil seals 20 and 21.

By the way, regarding this oil seal,
Various developments are being made in terms of structure and materials,
It is not always sufficient in sealing performance and durability,
Although a roll socks type sealing system has been proposed, the current situation is not sufficient in durability.

When the Stirling refrigerator is operating, the temperature of the crank chamber 26 rises and the internal pressure rises. This increase in the pressure in the crank chamber mechanically burdens the oil seal and causes deterioration, and the pressure increases the oil rise, which has a problem in that performance is adversely affected. Further, there is also a problem that the reciprocating motion of the compression piston and the expansion piston causes a pressure fluctuation on the back side thereof, which adversely affects the oil seal.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve various problems peculiar to the above-mentioned Stirling refrigerator. The objects of the present invention are as follows. (1) To realize a bellows for oil seal of a piston rod, which prevents oil rise and has a long service life, and improves the performance and life of a Stirling refrigerator. (2) Even if a general oil seal is used, deterioration and oil rise cannot be prevented even if a general oil seal is used. Although this may adversely affect the bellows itself and the performance of the refrigerator, the rise in pressure due to the rise in the temperature of the crankcase can be solved by employing a buffer tank having a bellows for pressure adjustment. (3) The problem of pressure fluctuation occurring on the back side of the piston that compresses or expands, which adversely affects the performance of the oil seal and the refrigerator, is solved by employing a buffer tank with or without a bellows for pressure adjustment. (4) The problem of pressure fluctuation occurring on the back side of the piston is solved by utilizing the space in the housing having the crank chamber. Specifically, the rear side of the piston communicates with the space in the housing having the crank chamber via the oil catching device to eliminate the problem. In this case, the throttle device for adjusting the oil catching device may be used in common (used in series).

[0008]

According to the present invention, there is provided a housing having a crank chamber, a cylinder disposed adjacent above the crank chamber, and reciprocating in the cylinder. A piston or displacer that compresses or expands the working gas, a piston rod that is linked to the crank in the crank chamber and has one end connected to the piston or displacer, and an opening at the top of the crank chamber through which the piston rod passes. In a Stirling heat engine comprising an oil seal provided, an end of the oil seal is fixed to the piston rod in the cylinder, and a base end of the oil seal has an opening at the top of the crank chamber through which the piston rod passes. An oil seal bellows fixed to the periphery of the oil seal. By providing the bellows to provide a Stirling heat engine, characterized in that the space from the oil into the cylinder penetration in the housing is prevented.

The space between the back side of the piston that compresses or expands the working gas and the space inside the housing is
A buffer tank for absorbing pressure fluctuations in the space on the back side and pressure rise in the housing is provided in communication with communication means, and the buffer tank has a bellows for pressure adjustment provided therein. It is partitioned into a chamber on the opening side and a chamber on the closing wall side of the pressure adjusting bellows,
The chamber on the opening side and the chamber on the closing wall side may be configured to communicate with either the space on the back side of the piston or the space in the housing.

In order to absorb the pressure fluctuation in the space on the back side, the space on the back side of the piston for compressing or expanding the working gas and the space in the housing are adjusted to
It is good also as a structure provided in communication via the oil capture device.

A buffer tank for absorbing pressure fluctuations in the rear space is provided in a space on the rear side of the piston for compressing or expanding the working gas through communication means. And an oil trapping device or an oil trapping device and a pressure regulating throttle device provided in communication with each other, and a space on the back side of a piston for compressing or expanding the working gas, and a space in the housing. And the pressure may be adjusted.

As the oil seal, in addition to the bellows for the oil seal, an annular pressure-resistant oil seal that is in pressure contact with the piston rod is provided at an opening at the top of the crank chamber, and a piston for compressing or expanding the working gas is provided. A buffer tank is provided between the space on the back side and the seal chamber formed by the oil seal bellows in order to reduce invalid pressure fluctuation generated on the rear side of the piston and invalid pressure fluctuation generated in the seal chamber. The buffer tank is provided with a pressure adjusting bellows therein, and is partitioned into a chamber on the opening side and a chamber on the closing wall side of the pressure adjusting bellows. The chamber on the opening side and the chamber on the closing wall side respectively communicate with the space on the back side of the piston or one of the spaces on the seal chamber. It may be configured that.

Further, in order to solve the above-mentioned problems, the present invention provides a housing having a crank chamber, a cylinder disposed above and adjacent to the crank chamber, and reciprocates in the cylinder to compress working gas. Or an expanding piston or displacer, a piston rod interlocked with a crank in the crank chamber, one end of which is connected to the piston or displacer, and an oil disposed in an opening at the top of the crank chamber through which the piston rod passes. A Stirling heat engine comprising a seal and
Between the space on the back side of the piston and the space in the housing, a buffer tank for absorbing the pressure fluctuation in the space on the back side and the pressure rise in the housing is communicated via communication means. In the buffer tank, a bellows for pressure adjustment is disposed inside, and the buffer tank is partitioned into a chamber on the opening side and a chamber on the closing wall side of the bellows for pressure adjustment, and the chamber on the opening side is provided. The chamber on the side of the closing wall and the space on the side of the closing wall communicate with one of the space on the back side of the piston and the space in the housing, respectively.

Further, in order to solve the above-mentioned problems, the present invention provides a housing having a crank chamber, a cylinder disposed above and adjacent to the crank chamber, and reciprocates in the cylinder to compress working gas. Or an expanding piston or displacer, a piston rod interlocked with a crank in the crank chamber, one end of which is connected to the piston or displacer, and an oil disposed in an opening at the top of the crank chamber through which the piston rod passes. A Stirling heat engine comprising a seal and
A buffer tank for absorbing pressure fluctuation in the space on the back side and pressure rise in the housing is communicated between the space on the back side of the piston and the space in the housing via communication means. Provided between the buffer tank and the space in the housing, an oil supplementing device or an oil catching device and a pressure regulating throttle device are provided in communication with each other, and a space on the back side of the piston that compresses or expands the working gas. And a Stirling heat engine characterized in that the pressure in the space inside the housing can be adjusted.

Further, in order to solve the above-mentioned problems, the present invention provides a housing having a crank chamber, a cylinder disposed above and adjacent to the crank chamber, and reciprocates in the cylinder to compress working gas. Or, an expanding piston or displacer, a piston rod interlocked with a crank in the crank chamber, one end of which is connected to the piston or displacer, and an oil seal disposed at an opening at the top of the crank chamber through which the piston rod passes. In the Stirling heat engine comprising: a space on the back side of the piston and a space in the housing are communicated via an oil capturing device in order to absorb pressure fluctuations in the space on the back side. A Stirling heat engine is provided.

The pressure adjusting bellows may be constituted by one bellows or a pair of opposed bellows facing each other.

Further, a configuration may be employed in which a compressive force is applied to the closing wall of the pressure adjusting bellows by a spring.

The bellows for pressure adjustment may be guided by a guide member with respect to the buffer tank, and may be configured to smoothly expand and contract without bending.

The buffer tank may be provided with one or more buffer tanks.

The working gas of the Stirling heat engine is nitrogen, helium or hydrogen, and the cold refrigerant is any one of a group including ethyl alcohol, HFE, PFC, PFG, nitrogen and helium.

The Stirling heat engine includes a compression cylinder having a compression piston and an expansion cylinder having an expansion piston or a displacer, wherein the compression piston and the expansion piston or the displacer reciprocate with a phase difference. You may apply as a structure of an apparatus.

The Stirling heat engine may be applied as a Stirling refrigerator or a Stirling engine.

[0023]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings based on Embodiments 1 to 9 relating to a Stirling refrigerator. FIG. 2 is a view showing a first embodiment of the Stirling refrigerator according to the present invention. The outline of the Stirling refrigerating machine 22A of the first embodiment is characterized in that an oil seal bellows is provided to prevent oil rising, and a buffer tank with a pressure adjusting bellows communicating with the crank chamber is provided. It is characterized in that the pressure in the space inside the housing due to the temperature rise in the crank chamber and the pressure fluctuation in the space on the back side of the compression piston and the expanding piston with respect to the oil seal bellows are absorbed.

This will be described in detail with reference to FIG.
The housing 23 of the Stirling refrigerator 22A is formed of a casting, and the inside of the housing 23 is partitioned into a motor chamber 25 and a crank chamber 26 by a partition wall 24. Crank chamber 2
6 is provided with a rotary reciprocating conversion mechanism 28 that converts the rotational operation of the motor 27 into reciprocating motion. Motor room 2
5 and the crank chamber 26 are closed by lids 29 and 30, respectively.

In the housing 23, a crankshaft 34 penetrating the partition wall 24 and supported by bearings 31, 32, 33 is rotatably arranged. The motor 27 includes a stator 35 and a rotor 36.
6, a crankshaft 34 is fixed at the center.

The rotary reciprocating conversion mechanism 28 includes the crank chamber 2
6, a crank portion 37 of the crankshaft 34 extending into
38, connecting rods 39 and 40 connected to the crank portions 37 and 38, and cross guide heads 41 and 42 attached to the ends of the connecting rods, and function as drive transmission means of the Stirling refrigerator 22A. I have.

The cross guide heads 41 and 42 are arranged so as to reciprocate in cross guide liners 43 and 44 provided on the inner wall of the cylinder of the housing 23. When the motor 27 rotates forward, the crank portions 37 and 38
8 is formed with a phase difference so that it moves ahead of the crank 37. As this phase difference, a phase difference of about 90 degrees is generally adopted.

Housing 2 of Stirling refrigerator 22A
A compression cylinder 45 and an expansion cylinder 46 are disposed above the third crank chamber 26. Compression cylinder 45
As the working gas, for example, helium, hydrogen, nitrogen, or the like is sealed in the expansion cylinder 46 and the housing 23.

The compression cylinder 45 has a compression cylinder block 47 fixed to the housing 23 with bolts or the like. A compression piston 48 provided with a piston ring reciprocates in the space of the compression cylinder block 47,
The upper part of this space is a high-temperature chamber (compression space) 49, in which the working gas is compressed to a high temperature.

The compression piston rod 50 has one end fixed to the compression piston 48 and the other end rotatably connected to the cross guide head 41. An oil seal bellows 53 is sealed so as to seal the opening 51 at the top of the housing 23.
Is fixed to the compression piston rod 50, and the lower end is fixed to the peripheral edge of the opening 51.

As a result, the compression cylinder 45 and the crank chamber 26 of the housing 23 are completely sealed, and oil from the crank chamber 26 is completely prevented from entering the compression cylinder 45. As the bellows 53 for oil seal, a formed bellows formed by integrally forming a metal material by press working or a welded bellows assembled by welding is used.

Since the sliding direction of the reciprocating compression piston 48 is reversed at the top dead center and the bottom dead center, the speed becomes zero.
The velocity is slow near the top dead center and the bottom dead center, and the amount of change in volume per unit time is small, and at the respective middle points when moving from the bottom dead center to the top dead center and from the top dead center to the bottom dead center. The maximum speed is reached, and the amount of change in volume due to the movement of the piston per unit time is also maximized.

On the other hand, the expansion cylinder 46 is located slightly above the compression cylinder,
The expansion cylinder block 54 is fixed to the expansion cylinder block 3. An expansion piston 55 provided with a piston ring slides back and forth in the space of the expansion cylinder block 54, and the upper part of this space is a low-temperature chamber (expansion space) 56. The working gas therein expands to a low temperature. The expansion piston 55 moves ahead of the compression piston 48 by a phase of about 90 degrees.

The expansion piston rod 57 has one end fixed to the expansion piston 55 and the other end rotatably connected to the cross guide head 42. The upper end of the oil seal bellows 58 is fixed to the expansion piston rod 57 so as to seal the upper opening 52 of the housing 23, and the lower end of the oil seal bellows 58 is fixed to the periphery of the opening 52 of the housing 23.

As a result, the expansion cylinder 46 and the crank chamber 26 are completely sealed and completely prevented from entering the expansion cylinder 46 from the crank chamber 26 along the expansion piston rod 57. The bellows 58 for oil seal
The same bellows as for the compression cylinder is used.

A buffer tank 59 is provided in the Stirling refrigerator 22A, and a pressure adjusting bellows 61 which expands and contracts in the axial direction is provided in the buffer tank 59. With the bellows 61 for pressure adjustment, the buffer tank 59 is divided into a chamber 63 on the opening side of the bellows 61 for pressure adjustment and a chamber 65 on the closing wall side of the bellows 61 for pressure adjustment.
Is divided into

A chamber 63 on the opening side of the bellows 61 for pressure adjustment.
Is connected to a space 69 on the back side of the compression piston 48 of the compression cylinder by a pipe 67. A communication hole 69 'is formed in the partition wall between the chamber 69 and the space 70 on the back side of the expansion piston 55 of the expansion cylinder, and the two spaces 69, 70 communicate with each other. The chamber 65 on the closing wall side of the pressure adjusting bellows 61 communicates with the motor chamber 25 and the crank chamber 26 of the housing 23 by a pipe 71 (in this regard, the motor chamber 25 and the crank chamber 26 are separated from each other by the partition wall 24). However, since they are not partitioned off from each other in an airtight manner but are in a communicating state, in this specification, the expression is referred to as communicating with a space in the housing 23.)
As these pressure adjusting bellows 61, metal bellows or resin or rubber bellows are used as in the case of the oil seal bellows 53 and 58.

The expansion cylinder block 54 is provided with an annular manifold 73 communicating with the high temperature chamber (compression space) 49 of the compression cylinder 45, and further includes a heat-radiating heat exchanger 74, a regenerator 75, and a cooling heat-exchanger. The devices 76 are annularly arranged so as to communicate sequentially with each other. A communication hole 77 is formed near the upper end of the compression cylinder block 45, so that the high-temperature chamber (compression space) 49 and the low-temperature chamber (expansion space) 56 communicate with the communication hole 77, the manifold 73, and the heat radiating heat. It is configured to sequentially communicate with each other via an exchanger 74, a regenerator 75, and a heat exchanger 76 for cooling.

The heat radiating heat exchanger 74 is an annular type heat exchanger, for example, a shell and tube type heat exchanger (a number of tubes through which working gas flows into an annular heat exchange chamber are axially penetrated, A heat exchanger that cools the working gas by flowing cooling water into the heat exchange chamber is used.

The radiating heat exchanger 74 is connected to the cooling water circulation line 7.
8 and the radiator 79 via the cooling water pump P1 to circulate the cooling water. The cooling water heated and exchanged by the heat radiating heat exchanger 74 is cooled by the cooling fan 80 of the radiator 79. The cooling water circulation pipe 78 is connected to a water reservoir tank 82 via a reservoir valve 81. The radiator 79 is connected to an air vent 83 and a drain valve 84.

A cooling heat exchanger 76 is formed above the expansion cylinder block 54 (cold head 85). The cooling heat exchanger 76 is provided inside the working gas flow path 8.
6 and cooling fins are formed on the outside.
Various structures are adopted for the heat exchanger for cooling depending on its use. For example, a jacket wall may be provided at the top of the expansion cylinder block 54, and a cooling / cooling refrigerant such as ethyl alcohol, HFE, PFC, PFG, nitrogen, and helium may flow through the jacket wall.

The Stirling refrigerator of the present invention has a large refrigerating capacity by using two pistons of the compression cylinder 45 and the expansion cylinder 46 to increase the volume fluctuation of the space filled with the working gas of the Stirling refrigerator. A Stirling refrigerator 22A can be provided.

Next, the operation of the Stirling cooling apparatus according to the embodiment of the present invention will be described. The crankshaft 34 is rotated in the forward direction by the motor 27, and the crank portions 37 and 38 in the crank chamber 26 are rotated out of phase with each other.
The cross guide heads 41, 4 are connected via connecting rods 39, 40 rotatably connected to the crank portions 37, 38.
2 reciprocates in the cross guide liners 43 and 44. Each of the cross guide heads 41 and 42 has a compression piston rod 5
The compression piston 48 and the expansion piston 55 connected via the zero and the expansion piston rod 57 reciprocate with a phase difference from each other.

While the expansion piston 55 moves slowly near the top dead center ahead of about 90 degrees, the compression piston 48 moves rapidly toward the top dead center near the middle to perform the compression operation of the working gas. The compressed working gas flows into the heat-radiating heat exchanger 74 through the communication hole 77 and the manifold 73.
The working gas that has radiated heat to the cooling water in the radiating heat exchanger 74
It is cooled by the regenerator 75 and flows into the low temperature chamber (expansion space) 56 through the flow path 86.

When the compression piston 48 is slowly moving near the top dead center, the expansion piston 55 is rapidly moved toward the bottom dead center, and the working gas flowing into the low temperature chamber (expansion space) 56 is rapidly expanded. Cold heat is generated. Thereby, the cold head 85 surrounding the expansion space is cooled to a low temperature.

When the expansion piston 55 moves from the bottom dead center to the top dead center, the compression piston 48 moves from the intermediate position to the bottom dead center, and the working gas is regenerated from the low temperature chamber (expansion space) 56 through the flow path 86. The regenerator 75 stores the cold heat of the working gas flowing into the regenerator 75. The cold stored in the regenerator 75 is transferred from the high-temperature chamber 49 to the heat-radiating heat exchanger 7 as described above.
The working gas sent through 4 is reused for cooling again.

The cold heat of the cold head 85 is supplied to a freezer, a refrigerator, a throw-in cooler, a low-temperature liquid circulator, a low-temperature incubator for various temperature characteristic tests, a constant-temperature bath, a heat shock test device, a freeze dryer, a cold cooler, and the like. Used for cold heat equipment.

The cooling water heat exchanged in the heat radiating heat exchanger 74 flows from the cooling water circulation line 78 to the radiator 79, where it is cooled by the cooling fan 80, and is again cooled.
Cycle to 4.

In the present invention, the space between the compression piston rod 50 and the opening 51 is completely sealed by the oil seal bellows 53, so that oil and oil mist rise from the crank chamber 26 along the compression piston rod 50. As a result, it is completely prevented from entering the compression cylinder 45. Similarly, since the space between the opening 52 and the expansion piston rod 57 is completely sealed by the bellows 58 for oil seal, oil and oil mist rise from the crank chamber 26 along the expansion piston rod 57 and expand. The entry into the cylinder 46 is completely prevented.

By the way, the temperature in the space inside the housing 23 rises during the operation of the Stirling refrigerator, and the pressure in the space inside the housing 23 rises with this temperature rise. Further, pressure fluctuations occur in the spaces 69 and 70 on the back side of the pistons of the compression piston 48 and the expansion piston 55. The pressure rise in the space inside the housing 23 and the space 6
Pressure fluctuations at 9 and 70 are absorbed in the buffer tank 59. In particular, when the pressure adjusting bellows 61 is provided, the pressure in the chamber 65 increases through the pipe 71 and the pressure adjusting bellows 61 contracts, thereby increasing the pressure due to the temperature increase in the space in the housing 23. , Thereby being effectively absorbed.

The motor 27 of the Stirling refrigerator 22A is rotated in the reverse direction. Then, the compression piston 48 and the expansion piston 55 have a phase difference of about 90 degrees, and the compression piston 48 acts as the expansion piston 55 and the expansion piston 55 Act as As a result, the working gas in the expansion space of the expansion cylinder is compressed by the expansion piston 55 to generate heat. This reverse rotation is used when performing a temperature control operation by a Stirling refrigerator or when defrosting frost generated in a cold heat exchanger of a cold heat utilization device.

The reverse rotation causes the temperature of the expansion cylinder 46 to rise, and the so-called carbonization problem occurs in which the oil or oil mist that has risen up is heated and carbonized and adheres to the cylinder. Is completely prevented, so this carbonization problem does not occur.

(Embodiment 2) FIG. 3 is a view showing Embodiment 2 of the Stirling refrigerator according to the present invention. The outline of the Stirling refrigerator 22B according to the second embodiment is that an oil seal bellows is provided to prevent oil rise, a pressure rise due to a rise in the temperature of the crank chamber, a compression piston and an expanding piston are applied to the oil seal bellows. In order to prevent adverse effects due to pressure fluctuations in the space behind the
It is characterized in that two buffer tanks with pressure adjusting bellows communicating with the space on the back side and the space in the housing 23 are provided. The second embodiment is different from the first embodiment in the configuration related to the point that two buffer tanks are provided, but the configuration and operation are the same in other respects.

This will be described in detail. In FIG.
The Stirling refrigerator 22B is provided with two buffer tanks 59 and 60.
The pressure adjusting bellows 6 which expands and contracts in the axial direction
1, 62 are provided. This bellows 6 for pressure adjustment
The buffer tanks 59 and 60 are partitioned into chambers 63 and 64 on the opening side of the pressure adjusting bellows and chambers 65 and 66 on the closing wall side of the pressure adjusting bellows.

The chambers 63, 6 on the opening side of the pressure adjusting bellows.
4 communicates with the spaces 69, 70 on the back side of the compression piston 48 and the expansion piston 55 by pipes 67, 68.
The chambers 65 and 66 on the closing wall side of the pressure adjusting bellows are provided with pipes 7.
1 and 72 communicate with the space in the housing 23. Metal bellows are used for these pressure adjusting bellows 61 and 62 in the same manner as the oil seal bellows 53 and 58.

The operation of the second embodiment is substantially the same as that of the first embodiment. However, in the second embodiment, the pressure rise due to the temperature rise in the space in the housing 23 and the pressure fluctuation in the back spaces 69 and 70 are reduced by two. Two buffer tanks 59, 6 with bellows
Absorbed by 0.

(Embodiment 3) FIG. 4 is a view showing Embodiment 3 of a Stirling refrigerator according to the present invention. In the Stirling refrigerator 22C of the third embodiment, an oil seal bellows is provided to prevent oil from rising. Due to the pressure rise caused by the rise in the temperature of the crank chamber, a pressure difference occurs between the inside and outside of the oil seal bellows, and pressure fluctuations occur in the spaces 69, 70 on the rear side of the pistons of the compression piston 48 and the expansion piston 55. To prevent this, spaces 69, 7 on the back side
0 is communicated with the space in the housing 23 through an oil trap (oil trap) 87.

More specifically, the spaces 69 and 70 on the rear side of the compression piston are provided so as to communicate with the space in the housing 23 via the pipe 67, the oil catching device 87 and the pipe 71. Fluctuations in pressure in the space on the piston rear side of the compression piston 48 and the expansion piston 55 are absorbed in the space in the housing 23, thereby preventing a pressure difference between the inside and outside of the oil seal bellows from occurring.

The oil catching device 87 is provided so that oil and oil mist in the crank chamber do not flow into the spaces 69 and 70 on the rear side of the compression piston and the expansion piston. An appropriate structure such as an oil filter is selected according to the contents. Also, a getter agent or the like corresponding to the contaminants is used so that the contaminants can be captured.

(Embodiment 4) FIG. 5 is a view showing Embodiment 4 of a Stirling refrigerator according to the present invention. In the Stirling refrigerator 22D according to the fourth embodiment, oil seal bellows 53 and 58 are provided to prevent oil rising, and the pressure in the spaces 69 and 70 on the back side of the compression piston 48 and the expansion piston 55. A buffer tank 59 '(buffer tank without a bellows for pressure adjustment) for absorbing fluctuations is provided. Further, an oil catching device 87 is provided so that oil and oil mist in the crank chamber do not flow into the spaces 69 and 70 on the rear side of the compression piston and the expansion piston.

In the fourth embodiment, the oil catching device 87
A pressure adjusting throttle device 88 is connected in series with
The pressure adjusting throttle device 88 is provided to prevent the oil mist in the housing 23 from directly reaching the oil catching device 87, and is provided as necessary. Specifically, a capillary tube or a pressure regulating valve is used as the pressure regulating throttle device 88.

(Embodiment 5) FIG. 6 is a view showing Embodiment 5 of the Stirling refrigerator according to the present invention. The outline of the Stirling refrigerator 22E of the fifth embodiment is applied to a case where the pressure rise due to the temperature rise of the crank chamber 26 is small. The oil seal of the specification is provided, and the pressure rise caused by the temperature rise of the crankcase is dealt with by the pressure-resistant oil seal, and the pressure fluctuation inside and outside the oil seal bellows is absorbed by the pressure adjustment bellows in the buffer tank. It is characterized by the following.

In FIG. 6 (a), between the upper openings 51, 52 of the housing 23 and the compression piston rods 50, 57, the structure is a general structure made of rubber, resin, etc. Seal (oil seal ring) 8
9, 90 are provided. And the compression piston 48
The spaces 69, 70 on the rear side of the expansion piston 55 communicate with each other through an opening 91, and the bellows 53, 58 for oil sealing are formed so as to define a seal chamber 92 in the spaces 69, 70. Are integrally formed.
The bellows 53 and 58 for oil seal have a bellows-like cylindrical portion with the top fixed to the compression piston rod 50 and the expansion piston rod 57, respectively, and the lower peripheral edge is fixed to the inner surfaces of the compression cylinder 45 and the expansion cylinder 46. Have been.

A buffer tank 59 having the same structure as in the first embodiment is provided, and a bellows 61 for pressure adjustment is formed inside the buffer tank 59. The chamber 63 on the opening side communicates with the spaces 69 and 70 via the pipe 67, and the chamber 65 on the closing side communicates with the seal chamber 92 via the pipe 71. FIG.
As shown in (b), the direction of the buffer tank 59 may be reversed left and right.

The fifth embodiment having such a structure is applied when the pressure rise due to the temperature rise of the space in the housing 23 is small as described above, and is a pressure-resistant oil seal (oil seal ring) 89, Reference numeral 90 prevents oil rising and also prevents the seal chamber 92 from being affected by a pressure increase due to a temperature rise in the space in the housing 23.

Further, due to the reciprocating motion of the compression piston 48 and the expansion piston 55, a pressure fluctuation occurs between the rear space 69, 70 and the seal chamber 92, but is absorbed by the pressure adjusting bellows 61 of the buffer tank 59. Canceled. The sixth embodiment differs from the first embodiment in the structure for the above-described seal and pressure adjustment, but has the same other structures and functions.

(Embodiment 6) FIG. 7 is a view showing Embodiment 6 of a Stirling refrigerator according to the present invention. The outline of the Stirling refrigerator 22F of the sixth embodiment is as follows. A conventional Stirling refrigerator having a general oil seal made of rubber or resin for preventing oil rising is provided with a bellows for pressure adjustment for adjusting pressure of a crank chamber. It is characterized by a configuration provided with a buffer tank.

The sixth embodiment is different from the first embodiment in the sealing structure for preventing the oil from flowing up, but otherwise has the same configuration and functions. That is, in the sixth embodiment, without providing the oil seal bellows 53, 58, the general oil seals 93, 94 made of rubber, resin or the like are connected to the upper openings 51, 52 of the housing 23 and the compression piston rod 50. , 57 to prevent oil rising.

As in the first embodiment, the pressure rise due to the temperature rise in the space inside the housing 23 and the pressure fluctuation in the spaces 69, 70 on the back side of the compression piston and the expansion piston during the operation of the Stirling refrigerator are buffered. Tank 5
In 9, the pressure is absorbed by the bellows 61 for pressure adjustment. With such a configuration, it is possible to prevent the oil seals 93 and 94 from being easily damaged when the pressure in the crank chamber 26 rises and to prevent the oil from rising, thereby improving the durability and performance of the Stirling refrigerator.

(Embodiment 7) FIG. 8 is a view showing Embodiment 7 of the Stirling refrigerator according to the present invention. The outline of the Stirling refrigerator 22G of the seventh embodiment is similar to that of the sixth embodiment.
It is characterized in that a general oil seal made of rubber or resin is provided to prevent oil rising, and a buffer tank with a bellows for pressure adjustment is provided for pressure adjustment of the crank chamber. However, unlike the fifth embodiment, two buffer tanks 59 and 60 are provided as in the second embodiment.

When the Stirling refrigerator operates, the pressure rises due to the temperature rise in the space inside the housing 23 and the space 69 on the back side of the compression piston and the expansion piston.
The pressure fluctuation 70 is absorbed by the bellows 61 and 62 for pressure adjustment in the buffer tanks 59 and 60, respectively. With such a configuration, the problems of breakage of the oil seals 93 and 94 and oil rise that are likely to occur when the pressure in the crank chamber 26 rises are solved, and the durability and performance of the Stirling refrigerator are improved.

(Eighth Embodiment) FIG. 9 is a view showing an eighth embodiment of the Stirling refrigerator according to the present invention. The outline of the Stirling refrigerating machine 22H of the eighth embodiment is as follows. A general oil seal made of rubber or resin for preventing oil rising is provided, and the space 6 on the back side of the compression piston 48 and the expansion piston 55 is provided.
A buffer tank 59 'without a bellows for absorbing pressure fluctuations of the pressure chambers 9 and 70 (a buffer tank without a bellows for pressure adjustment) is provided, and oil and oil mist in the crank chamber is compressed by a compression piston. Further, an oil catching device 87 is provided so as not to flow into the spaces 69, 70 on the rear side of the expansion piston.

Further, a pressure adjusting throttle device 88 is connected in series with the oil catching device 87 as required. As in the fourth embodiment, a capillary tube or a pressure regulating valve is used as the pressure regulating throttle device 88.

As in the first embodiment, the temperature rise in the space inside the housing 23 and the space 6 on the back side of the compression piston and the expansion piston during the operation of the Stirling refrigerator.
The pressure fluctuations 9 and 70 are received by the pressure adjusting throttle device 88 and the buffer tank 59. With such a configuration, it is possible to prevent problems such as breakage of the oil seal and oil rise that are likely to occur when the pressure in the crank chamber rises, and improve the durability and performance of the Stirling refrigerator.

(Embodiment 9) FIG. 10 is a view showing a ninth embodiment of a Stirling refrigerator according to the present invention. The Stirling refrigerator 22I according to the ninth embodiment includes a general oil seal 93, 94 made of rubber, resin, or the like.
3 and the compression piston rods 50, 5
7, the space 69, 70 on the back side of the compression piston and the expansion piston and the space in the housing 13 are connected to the pipe 67, the oil catching device 87,
1 to prevent pressure fluctuations occurring in the spaces 69 and 70.

Next, the structure of the buffer tank with bellows used in the above embodiment will be described below. FIG. 11 is a view showing some specific examples of the buffer tank and the bellows for pressure adjustment. FIG. 11 (a)
It has a basic structure consisting of one bellows, and is the same as that already used in the above embodiments. The bellows 6 for pressure adjustment is used for static fluctuations in which the pressure in the crankcase rises during operation of the Stirling refrigerator.
Although the movement of No. 1 is slow, the displacement amount becomes large. or,
With respect to the dynamic pressure fluctuation on the back side due to the reciprocating motion of the expansion piston and the like, the displacement amount is small and the operation becomes a vibratory operation.

FIG. 11B shows a bellows 61 for pressure adjustment.
, A compression coil spring 95 applies an initially set compression force. With such a configuration, the displacement amount of the pressure adjusting bellows is (pressure rise of the crank chamber−initial setting compression) + the pressure fluctuation on the back side of the expansion piston and the like,
Is obtained. Therefore, since the displacement due to the increase in the pressure of the crank chamber is given at the initial stage, the bellows approaches the free length so that the displacement amount is eliminated during operation, so that the life of the bellows can be extended.

FIG. 11C shows a pair of left and right pressure adjusting bellows 61 and 61 ′ provided integrally in a buffer tank.
This is a structure of a bellows for facing pressure adjustment. Left and right spaces 96 outside the pressure adjustment bellows 61, 61 ',
96 ′ communicate with each other through a communication hole 98 that communicates with the central support 97. Bellows 61, 6 for pressure adjustment
The internal space 99 of 1 'is communicated with the back side of the compression piston or the like, and the left and right spaces 96, 96' outside the pressure adjusting bellows.
To the crank chamber side. Since this buffer tank is provided with two left and right pressure adjusting bellows 61 and 61 ', each pressure adjusting bellows can be made relatively short, so that bending in a direction (lateral direction) perpendicular to the expansion and contraction direction can be eliminated. .

FIG. 11D shows a configuration in which compression coil springs 95 and 95 ′ are provided between the opposed pressure adjusting bellows 61 and 61 ′ and inner surfaces of both ends of the tank 59. As a result, the same operation and effect as those in FIG. That is, since the displacement due to the increase in the pressure of the crank chamber is given at the beginning, the bellows approaches the free length so that the displacement amount is eliminated during the operation, so that the life of the bellows can be extended.

FIG. 12 is a view showing a guide structure of the bellows for pressure adjustment. When the size of the pressure adjusting bellows in the direction of expansion and contraction is large, that is, when the length thereof is long, the bellows are bent in the lateral direction. As a solution to this, as shown in FIG. 12A, an annular guide 100 made of resin or the like sliding on the inner surface of the buffer tank is attached to the tip of the pressure adjusting bellows.

As shown in FIG. 12 (b), a guide bar 101 is protruded from the distal end surface of the bellows for pressure adjustment, and a guide cylinder 1 is provided on the inner end surface of the buffer tank opposed thereto.
02 is provided to guide the guide bar slidably. If such a guide structure is applied to the bellows for pressure adjustment provided in each of the above embodiments, the problem of the bending can be solved. FIG. 12 (c) shows a structure in which this guide means is used for a facing type pressure adjusting bellows.

Although the embodiments of the present invention have been specifically described based on the embodiments, the present invention is intended to embody the technical concept within the scope described in the claims.
It goes without saying that there are various embodiments without being limited to the above embodiments. In the above embodiment, a two-piston type Stirling refrigerator is used. However, it goes without saying that the present invention can be applied to other types of Stirling refrigerators such as a displacer type.

[0083]

According to the Stirling refrigerator of the present invention having the above configuration, the following effects can be obtained. (1) The space between the housing, the compression piston rod and the expansion piston rod is completely sealed by oil seal bellows, respectively, so that contamination due to oil rise (dirt due to oil rise) can be prevented. Moreover, an oil seal with excellent durability is realized, and the performance and life of the Stirling refrigerator are improved.

(2) Since the pressure rise due to the rise in the temperature of the crank chamber is eliminated by providing a buffer tank with or without a pressure adjusting bellows, the pressure generated inside and outside the oil seal bellows due to this pressure rise. Fluctuations or problems such as general oil seal deterioration and oil rising can be prevented.

(3) The problem of pressure fluctuation occurring on the rear side of the piston that compresses or expands, which adversely affects the performance of the oil seal and the refrigerator, can be solved by employing a buffer tank with or without a bellows for pressure adjustment. .

(4) Since the above-mentioned problems unique to the Stirling refrigerator can be solved, a low-melting-point refrigerant such as ethyl alcohol, nitrogen or helium can be used as a refrigerant other than Freon as a working gas. It is possible to provide a refrigeration system that can be used in a wide range of applications using cold heat, has a large refrigeration capacity, and is capable of performing heating and cooling operation by forward and reverse operation of a motor, which is applicable to a wide range of applications. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing an entire Stirling refrigerator.

FIG. 2 is a diagram showing a first embodiment of a Stirling refrigerator according to the present invention.

FIG. 3 is a view showing a second embodiment of the Stirling refrigerator according to the present invention.

FIG. 4 is a view showing a third embodiment of the Stirling refrigerator according to the present invention.

FIG. 5 is a diagram showing a fourth embodiment of the Stirling refrigerator according to the present invention.

FIG. 6 is a view showing a fifth embodiment of the Stirling refrigerator according to the present invention.

FIG. 7 is a view showing a sixth embodiment of the Stirling refrigerator according to the present invention.

FIG. 8 is a view showing a seventh embodiment of the Stirling refrigerator according to the present invention.

FIG. 9 is a view showing Embodiment 8 of the Stirling refrigerator according to the present invention.

FIG. 10 is a ninth embodiment of the Stirling refrigerator according to the present invention.
FIG.

FIG. 11 is a view showing a specific example of a pressure adjusting bellows of a buffer tank according to the present invention.

FIG. 12 is a view showing a specific example of a guide for a pressure adjusting bellows according to the present invention.

[Explanation of symbols]

22, 22A-F Stirling refrigerator 23 Housing 25 Motor chamber 26 Crank chamber 27 Motor 45 Compression cylinder 46 Expansion cylinder 48 Compression piston 49 High temperature chamber 50 Compression piston rod 53, 58 Bellows for oil seal 55 Expansion piston 56 Low temperature chamber 57 Expansion piston Rods 59, 60 Buffer tanks 61, 61 ', 62 Bellows for pressure adjustment of buffer tank 87 Oil trapping device (oil trap) 88 Throttling device for pressure adjustment 89, 90 Oil seal (oil seal ring) with pressure resistance 93, 94 Oil Seal (oil seal ring) 95, 95 'Compression coil spring 100 Guide for bellows for pressure adjustment

Claims (15)

[Claims] 1. A housing having a crank chamber, a cylinder disposed above and adjacent to the crank chamber, a piston or displacer for reciprocating in the cylinder to compress or expand a working gas, and A Stirling heat engine, comprising: a piston rod that is linked to a crank and has one end connected to the piston or displacer; and an oil seal disposed at an opening at the top of the crank chamber through which the piston rod passes. The oil seal comprises an oil seal bellows having a distal end fixed to the piston rod in the cylinder and a proximal end fixed to a peripheral edge of an opening at the top of the crank chamber through which the piston rod passes. By providing bellows for Stirling heat engine, characterized in that the entry of oil into the cylinder is prevented from between. 2. A pressure fluctuation in the space on the back side and a pressure rise in the housing are absorbed between a space on the back side of the piston for compressing or expanding the working gas and a space in the housing. A buffer tank is provided in communication with communication means through a communication means. The buffer tank has a pressure adjusting bellows disposed therein, and a chamber on the opening side and a chamber on the closing wall side of the pressure adjusting bellows. And the chamber on the opening side and the chamber on the closing wall side are respectively communicated with either the space on the back side of the piston or the space in the housing. The Stirling heat engine according to claim 1. 3. A space on the back side of the piston for compressing or expanding the working gas and a space in the housing are connected via an oil trapping device to absorb pressure fluctuations in the space on the back side. The Stirling heat engine according to claim 1, wherein the Stirling heat engine is in communication. 4. A buffer tank for absorbing pressure fluctuations in the space on the back side is provided in a space on the back side of the piston for compressing or expanding the working gas through communication means, and the buffer tank is provided. And the space in the housing,
An oil catching device or an oil catching device and a pressure adjusting throttle device are provided in communication with each other, so that the space on the back side of the piston that compresses or expands the working gas and the space inside the housing can be pressure-adjusted. The Stirling heat engine according to claim 1, characterized in that: 5. An oil seal having an annular pressure-resistant specification, which is in pressure contact with the piston rod, is provided at the opening at the top of the crank chamber, in addition to the oil seal bellows, as the oil seal, and a piston for compressing or expanding the working gas is provided. A buffer tank is provided between the space on the back side and the seal chamber formed by the oil seal bellows in order to reduce invalid pressure fluctuation generated on the rear side of the piston and invalid pressure fluctuation generated in the seal chamber. The buffer tank is provided with a pressure adjusting bellows therein, and is partitioned into a chamber on the opening side and a chamber on the closing wall side of the pressure adjusting bellows. The chamber on the opening side and the chamber on the closing wall side communicate with either the space on the back side of the piston or the space on the seal chamber, respectively. The Stirling heat engine according to claim 1, wherein: 6. A housing having a crank chamber, a cylinder disposed above and adjacent to the crank chamber, a piston reciprocating in the cylinder to compress or expand a working gas, and a crank in the crank chamber. A Stirling heat engine, comprising: a piston rod, which is linked to the piston, one end of which is connected to the piston; and an oil seal disposed at an opening at the top of the crank chamber through which the piston rod passes. And a buffer tank for absorbing pressure fluctuation in the space on the back side and pressure rise in the housing through communication means between the space and the space in the housing. Is provided therein with a bellows for pressure adjustment, which is divided into a chamber on the opening side and a chamber on the closing wall side of the bellows for pressure adjustment. Wherein the chamber on the opening side and the chamber on the closing wall side communicate with one of the space on the back side of the piston and the space in the housing, respectively. organ. 7. A housing having a crank chamber, a cylinder disposed above and adjacent to the crank chamber, a piston reciprocating in the cylinder to compress or expand a working gas, and a crank in the crank chamber. A Stirling heat engine, comprising: a piston rod, which is linked to the piston, one end of which is connected to the piston; and an oil seal disposed at an opening at the top of the crank chamber through which the piston rod passes. And a buffer tank for absorbing pressure fluctuations in the space on the back side and pressure rises in the housing through communication means, between the space and the space in the housing, Between the tank and the space inside the housing,
The oil supplementing device or the oil catching device and the pressure adjusting throttle device are provided in communication with each other, so that the pressure in the space on the back side of the piston that compresses or expands the working gas and the space in the housing can be adjusted. Stirling heat engine characterized. 8. A housing having a crank chamber, a cylinder disposed above and adjacent to the crank chamber, a piston reciprocating in the cylinder to compress or expand a working gas, and a crank in the crank chamber. A Stirling heat engine, comprising a piston rod having one end connected to the piston and an oil seal disposed at an opening at the top of a crank chamber through which the piston rod passes. A Stirling heat engine, wherein a space and a space in the housing are communicated via an oil capturing device to absorb pressure fluctuations in the space on the back side. 9. The Stirling heat engine according to claim 2, wherein the bellows for pressure adjustment comprises one bellows or a pair of opposed bellows facing each other. 10. The Stirling heat engine according to claim 2, wherein a compressive force is applied to a closing wall of the pressure adjusting bellows by a spring. 11. The pressure adjusting bellows is guided by a guide member with respect to a buffer tank, and is configured to smoothly expand and contract without bending. The Stirling heat engine according to 9 or 10. 12. The method according to claim 2, wherein one or more buffer tanks are provided.
The Stirling heat engine according to 6, 7, 9, 10, or 11. 13. The working gas of the Stirling heat engine is nitrogen, helium, or hydrogen, and the cold refrigerant is any one of a group including ethyl alcohol, HFE, PFC, PFG, nitrogen and helium. The Stirling refrigerating apparatus according to any one of claims 1 to 12, wherein 14. The Stirling heat engine includes a compression cylinder having a compression piston, and an expansion cylinder having an expansion piston or a displacer, and controls that the compression piston and the expansion piston or the displacer reciprocate with a phase difference. The Stirling refrigerating apparatus according to any one of claims 1 to 13, wherein: 15. The Stirling heat engine according to claim 1, wherein the Stirling heat engine is a Stirling refrigerator or a Stirling engine.