JP3723473B2 - Stirling refrigerator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to Stirling refrigeration, and more particularly to an oil seal bellows attachment structure attached as a rod seal for preventing oil spill.
[0002]
[Prior art]
In recent years, it has been used as a refrigeration device in place of CFCs for global environmental problems and has a wider operating temperature than conventional refrigeration equipment. Application to refrigeration equipment in all industrial fields such as liquid circulators, low temperature thermostats, thermostats, heat shock test equipment, freeze dryers, temperature characteristics test equipment, blood / cell storage equipment, cold coolers, and other various refrigeration equipment Stirling refrigerators are in the spotlight as possible refrigerators that are compact, have high coefficient of performance, and have good energy efficiency.
[0003]
[Problems to be solved by the invention]
In the Stirling refrigerator, there is a problem that oil or oil mist rises from the crank chamber along the piston rod, so-called oil rise. This oil rise adheres to the inner surface of oil and oil mist when entering the cylinder, affecting the sealing performance of the piston ring, not only significantly reducing durability and reliability, but also the heat that constitutes the Stirling refrigerator. As a result, the performance of the exchanger is deteriorated and the performance of the refrigerator is deteriorated. Conventionally, the piston rod is sealed with an oil ring seal in order to solve the problem of oil rising.
[0004]
By the way, this oil ring seal is generally made of rubber, and various developments have been made in terms of structure and material. However, the seal performance and durability are not necessarily sufficient.
[0005]
It is an object of the present invention to prevent oil from rising in a Stirling refrigerator and realize a long-life rod seal, improve the performance of the Stirling refrigerator, and improve the reliability and durability. It is to ensure the mounting of the bellows.
[0006]
The inventors have proposed a structure of an oil seal bellows (see Japanese Patent Application No. 10-365371) as a rod seal of a Stirling refrigerator. In the invention according to Japanese Patent Application No. 10-365371, a metal bellows for oil seal is provided between the space in the housing of the Stirling refrigerator and the compression cylinder and the expansion cylinder, and the crank is formed along the surface of the piston rod. This prevents oil from flowing into the compression cylinder and the expansion cylinder from the chamber.
[0007]
In such an oil seal bellows of the prior invention, when the lower end portion is fixed to a housing or a cylinder block via a seal, the excellent sealing property inherent to the oil seal bellows cannot be sufficiently exhibited. In the present invention, the oil seal bellows is fixed to the housing or the cylinder block by a more reliable sealing method, and the seal performance of the oil seal bellows is fully utilized to achieve a more perfect sealed structure. .
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a housing in which a motor and a crank are disposed, a cylinder fixed to the top of the housing via a fixing plate, a piston that reciprocates in the cylinder, and the crank. A Stirling refrigerator having an oil seal bellows and an oil seal bellows, one end of which is coupled to the piston and penetrating the housing, the upper end of the oil seal bellows being fixed to the upper mounting ring. The lower mounting portion is fixed to the lower mounting ring, the upper mounting ring is fastened to the flange portion of the piston rod via the upper sealing material, and the lower mounting ring is fixed to the fixing plate via the lower sealing material. And / or a Stirling refrigerator that is fastened to a housing.
[0009]
In order to solve the above problems, the present invention provides a housing in which a motor and a crank are disposed, a cylinder fixed to the top of the housing via a fixing plate, a piston that reciprocates in the cylinder, and the crank. A Stirling refrigerator having an oil seal bellows and an oil seal bellows, one end of which is coupled to the piston and penetrating the housing, the upper end of the oil seal bellows being fixed to the upper mounting ring. The lower end portion is welded to the annular mounting plate, the upper mounting ring is fastened to the flange portion of the piston rod via the upper sealing material, and the annular mounting plate is welded to the fixed plate. A Stirling refrigerator is provided.
[0010]
The upper seal material is an O-ring or a metal or resin gasket.
[0011]
The lower sealing material is an O-ring or a metal or resin gasket.
[0012]
A plurality of the cranks are provided, and a plurality of cylinders and pistons are provided corresponding to the plurality of cranks, and the plurality of pistons reciprocate with a phase difference from each other.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings based on examples. FIG. 1 is a front view illustrating the overall configuration of a Stirling refrigerator. FIG. 2 is a diagram for explaining a main part of the Stirling refrigerator, and FIG. 3 is a right side view partially in section. A feature of the present invention is an oil seal bellows mounting structure, and FIGS. 4 to 6 show different oil seal bellows mounting structures. Hereinafter, the overall configuration of the Stirling refrigerator will be described with reference to FIGS. 1 to 3, and the mounting structure of the oil seal bellows will be described with reference to FIGS.
[0014]
The housing 2 forming the main body of the Stirling refrigerator 1 is formed of a casting, and the inside thereof is held in a sealed state. The housing 2 includes a motor chamber 4 and a crank chamber 5 that communicate with each other via a partition wall 3. The motor chamber 4 is provided with a motor 6 capable of rotating in the forward and reverse directions. The crank chamber 5 is provided with a crankshaft 7 and connecting rods 8 and 9 which are driven to rotate by the motor 6 and cross guide heads 10 and 11. Etc. are arranged.
[0015]
The two crank portions 12 and 13 of the crankshaft 7 are formed with a phase difference so that the crank portion 13 moves ahead of the crank portion 12 when the motor 6 rotates forward. 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.
[0016]
A cylinder block 15 is attached to the upper portion of the crank chamber 5 in the housing 2 with a bolt 16 via a fixed plate 14. The cylinder block 15 forms a compression cylinder 17 and a part (lower part) of the expansion cylinder 18.
[0017]
A compression piston 19 reciprocates in the compression cylinder 17. An upper space (compression space) of the compression piston 19 in the compression cylinder 17 is a high temperature chamber 20, in which 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. An oil seal bellows 22 is attached between the compression piston rod 21 and the upper portion of the housing 2 to seal between the compression cylinder 17 and the crank chamber 5 and prevent oil from rising from the crank chamber 5.
[0018]
On the other hand, the lower part of the expansion cylinder 18 is composed of the cylinder block 15 as described above, and the upper part is composed of an inner cylinder 23 of a heat-dissipating heat exchanger 29 and an inner cylinder 24 of a cooling heat exchanger, which will be described later. ing. An expansion piston 25 reciprocates in the expansion cylinder 18, and a space (expansion space) above the expansion piston 25 in the expansion cylinder 18 is a low temperature chamber 26, in which the working gas expands and becomes a low temperature.
[0019]
The expansion piston rod 27 connects the expansion piston 25 and the cross guide head 11 and extends from the crank chamber 5 into the expansion cylinder 18. An oil seal bellows 28 is attached between the expansion piston rod 27 and the upper part of the housing 2 to seal between the expansion cylinder 18 and the crank chamber 5 to prevent oil from rising from the crank chamber 5. The expansion piston 25 moves ahead of the compression piston 19 by a phase of 90 degrees.
[0020]
A heat dissipating heat exchanger (high temperature side heat exchanger) 29, a regenerator 30 and a cooling heat exchanger (low temperature side heat exchanger) 31 are arranged in an annular shape so as to surround the expansion cylinder 18. Yes. A manifold (flow channel for working gas) 32 is formed at the lower end of the heat exchanger 29 for heat dissipation and around the expansion cylinder 18.
[0021]
A communication hole 33 that communicates the high temperature chamber 20 and the manifold 32 is formed at the upper end of the compression cylinder 17. 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 dissipation heat exchanger 29, the regenerator 30, and the cooling heat exchanger 31.
[0022]
The cylinder block 15 has a heat exchange housing 34 for heat dissipation in the upper part thereof. A heat exchanger cylinder 37 is fitted between the heat-dissipating heat exchange housing 34 and the inner cylinder 23 to constitute a heat-dissipating heat exchanger (high temperature side heat exchanger) 29. The heat exchanger cylinder 37 has a narrow groove 35 that forms a flow path for the working gas on its inner surface, and a heat radiating fin 36 on its outer surface.
[0023]
The working gas passes through the narrow groove 35, and cooling water flows through the heat radiation path 38 between the heat radiating heat exchange housing 34 and the heat radiating fins 36, whereby heat of the working gas is radiated to the cooling water. A cover plate 39 is fixed in a watertight manner on both left and right side surfaces of the cylinder block 15, and a cooling water passage 40 is formed between the cover plate 39 and the cylinder block 15. The cooling water passage 40 is formed to surround the compression cylinder 17 and the expansion cylinder 18 while communicating with the heat radiation passage 38 through the inlet 41.
[0024]
A cooling water inlet 42 is provided in the heat radiation path 38, an outlet 43 is provided in the cooling water path 40, and the inlet 40 and the outlet 43 are not shown, but the cooling water circulation path and the cooling water circulation pump And is connected to an air-cooled radiator (radiator) having a cooling fan.
[0025]
The lower part of the inner cylinder 24 is fitted with the inner cylinder 23 to constitute a part of the expansion cylinder 18. A cooling heat exchange housing 44 is disposed on the outer periphery of the upper part of the inner cylinder 24, and the cylinder block 15. The heat-dissipating heat exchange housing 34 is detachably fixed to the upper surface. The cooling heat exchange housing 44 has a plurality of narrow grooves 45 on its inner surface, is fitted with the inner cylinder 24 to form a working gas flow path 46, and has cooling fins 47 on its outer surface. Thus, a cooling heat exchanger (low temperature side heat exchanger) 31 is configured.
[0026]
This cooling heat exchanger 31 cools the cold refrigerant of the cold-use equipment that uses the cold of the Stirling refrigerator of the present invention. Air, water, alcohol, HFE, PFC or the like is used as the cold heat refrigerant.
[0027]
In an annular space between the inner cylinder 24 and the cooling heat exchange housing 44, a regenerator 30 made of a cold storage material such as a metal mesh is disposed.
[0028]
The space between the oil seal bellows 28 and the expansion piston 25 (the same applies to the space between the oil seal bellows 25 and the compression piston 15) is called a buffer space (buffer chamber) 48. The buffer space 48 is connected to the buffer tank 51 by a pipe 49, and the buffer tank 51 is connected to the crank chamber 5 (or the motor chamber 4) of the housing 2 by a pipe 50.
[0029]
Here, an oil seal bellows mounting structure which is a characteristic configuration of the Stirling refrigerator according to the present invention will be described. As described above, the oil seal bellows mounting structures of different modes are shown in FIGS. 4 to 6, respectively. First, a common configuration will be described with reference to FIGS.
[0030]
As the oil seal bellows 22 and 28, a metal-formed bellows integrally formed by pressing a metal material, a welded bellows assembled by welding, or the like is used. 4 to 6, the compression piston rod 21 and the expansion piston rod 27 extend through the openings 2 ′ and 2 ′ on the top wall of the housing 2, respectively. The oil seal bellows 22 and 28 seal the openings 2 'and 2'.
[0031]
The upper end 52 of the oil seal bellows 22 is welded to an annular upper mounting ring 53 shown in FIGS. 4 to 6 (a) and (b). The upper mounting ring 53 is placed on the flange portion 54 of the compression piston rod 21, is sandwiched from above by the compression piston 19, and is fastened with a bolt 55. Similarly, the upper end portion of the oil seal bellows 28 is welded to the upper mounting ring 53, and the upper mounting ring 53 is interposed between the flange portion 56 of the expansion piston rod 27 and the expansion piston 25 via the cylindrical body 57. Fastened with bolts 58.
[0032]
Here, a specific mounting structure of the oil seal bellows 22 and 28 shown in FIG. 4 will be described. As shown in FIG. 4B, an O-ring 59 (upper seal material) is attached to the flange portions 54 and 56, and a seal (completely between the flange portions 54 and 56 and the upper mounting ring 53 is completely formed. Sealing).
[0033]
The lower end portion 60 of the oil seal bellows 22 is welded to the upper portion 62 of the annular lower mounting ring 61 shown in FIGS. Similarly, the lower end portion 60 of the oil seal bellows 28 is welded to the upper portion 62 of the annular lower mounting ring 61. The flange 63 of the lower mounting ring 61 is placed on the upper surface of the peripheral edge of the opening 2 ′ at the top of the housing 2, and is clamped by a fixing plate 14 interposed between the housing 2 and the cylinder block 15. 16 is fastened.
[0034]
As shown in FIG. 4C, an O-ring 65 (lower seal material) is mounted in the groove 64 of the flange 63, and seals (completely seals) the lower mounting ring 61 and the fixing plate 14. Is doing).
[0035]
Next, a specific mounting structure of the oil seal bellows 22 and 28 in FIG. 5 will be described. As shown in FIG. 4B, a metal or resin gasket 66 (upper seal material) is attached between the flange portions 54 and 56 and the upper mounting ring 53. And the upper mounting ring 53 are sealed (completely sealed).
[0036]
The lower end portion 60 of the oil seal bellows 22 is welded to the upper portion 62 of the annular lower mounting ring 61 shown in FIGS. Similarly, the lower end portion 60 of the oil seal bellows 28 is welded to the upper portion 62 of the annular lower mounting ring 61. The flange 67 of the lower mounting ring 61 is placed on the upper surface of the periphery of the opening 2 ′ at the top of the housing 2, and is sandwiched between the fixing plate 14 interposed between the housing 2 and the cylinder block 15, and the bolt 16 It is fastened with.
[0037]
As shown in FIG. 5C, a metal or resin gasket 68 (lower sealing material) is mounted between the flange 67 and the fixing plate 14, and the lower mounting ring 61 and the fixing plate 14 are The seal (completely sealed) is performed.
[0038]
Next, a mounting structure unique to the oil seal bellows 22 and 28 in FIG. 6 will be described. Between the flange portions 54 and 56 and the upper mounting ring 53, as shown in FIG. 6B, a metal or resin gasket 66 (upper seal material) is mounted. Sealing (completely sealing) with the mounting ring 53 is performed.
[0039]
The lower end 60 of the oil seal bellows 22 is welded to an annular mounting plate 69 made of a thin plate, as shown in FIGS. Further, the annular mounting plate 69 is welded to the inner peripheral surface 70 of the opening of the fixed plate 14 ′. Similarly, the lower end portion 60 of the oil seal bellows 28 is welded to the annular mounting plate 69, and is welded to the inner peripheral surface 70 of the opening of the fixed plate 14 '. The fixing plate 14 ′ is interposed between the housing 2 and the cylinder block 15 and fastened with bolts 16.
[0040]
(Function)
Next, the operation of the Stirling refrigerator of the embodiment of the present invention having the above configuration will be described. The crankshaft 7 is rotated in the forward direction by the motor 6, and the crank portions 10 and 11 in the crank chamber 5 are rotated 90 degrees out of phase. The compression piston 19 and the expansion piston 25 have a phase difference of 90 degrees from each other via the connecting rods 8 and 9, the cross guide heads 19 and 11, the compression piston rod 21 and the expansion piston rod 27 connected to the crank portions 10 and 11. Reciprocates.
[0041]
While the expansion piston 25 is moving 90 degrees ahead and slowly moving near the top dead center, the compression piston 19 rapidly moves near the middle toward the top dead center to compress the working gas. The compressed working gas flows through the communication hole 33 and the manifold 32 into the narrow groove 35 of the heat dissipation heat exchanger 29 and dissipates heat to the cooling water flowing through the heat dissipation path 38. Further, the working gas is cooled by the cold stored in the regenerator 30 and flows into the low temperature chamber 26 (expansion space) through the narrow groove 45.
[0042]
When the compression piston 19 is slowly moving near the top dead center, the expansion piston 25 is suddenly moved toward the bottom dead center, and the working gas flowing into the low temperature chamber 26 (expansion space) is rapidly expanded to generate cold heat. appear. As a result, a head portion (referred to as a cold head) 48 including the cooling heat exchanger 31 is cooled to a low temperature.
[0043]
Then, in the cooling heat exchanger 31, the cold refrigerant of the cold-use equipment 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 is moving from the intermediate position to the bottom dead center, and the working gas passes from the low temperature chamber 26 through the narrow groove 45 of the cooling heat exchanger and the regenerator. The refrigerating machine 30 stores the cold heat that flows into the working gas 30 and has the working gas. The cold stored in the regenerator 30 is reused to cool again the working gas sent from the high temperature chamber 20 through the heat dissipation heat exchanger 29 as described above.
[0044]
The cold refrigerant cooled by the cooling heat exchanger 31 of the Stirling refrigerator 1 is supplied to various cold utilization devices through the outflow pipe 71. For example, the cold refrigerant is sent to a heat exchanger in a cold energy utilization device such as a freezer, and performs freezing or cooling action in the cold energy utilization device. Then, after the cold energy is utilized in the cold energy utilization device, the cold refrigerant is circulated back to the cooling heat exchanger 31 of the Stirling refrigerator 1 through the inflow pipe 72 from the cold energy utilization device.
[0045]
Cooling water sent from a radiator (radiator) flows into the heat-dissipating heat exchanger 38 from the inlet 42 and passes through the heat-radiating path 38 to cool the working gas. Further, the 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. Thereafter, the cooling water flows out from the outlet 43, is cooled by the cooling fan in the radiator, and is circulated again to the heat exchanger 29 for heat radiation.
[0046]
The buffer tank 51 makes the buffer space 48 and the housing 2 have equal pressure, absorbs the pressure fluctuation in the buffer space 48, absorbs the pressure fluctuation in the housing 2, and does not affect the buffer space. It has a function.
[0047]
In the present invention, the upper end 52 and the lower end 60 of the oil seal bellows 22 and 28 are welded to the upper mounting ring 53 and the lower mounting ring 61 (the annular mounting plate 69 shown in FIG. 6), respectively. The upper mounting ring 53 and the lower mounting ring 61 (the annular mounting plate 69 shown in FIG. 6) are sealed to the piston rod (compression piston rod 21 and expansion piston rod 27) and the fixed plate 14 via an O-ring or gasket. (The one shown in FIG. 6 is fixed by direct welding).
[0048]
Due to the mounting structure of the oil seal bellows 22 and 28, the compression cylinder 17 and the expansion cylinder 18 and the crank chamber 5 of the housing 2 are completely sealed from each other. Oil rising into the expansion cylinder 18 is completely prevented.
[0049]
Although the embodiments of the present invention have been specifically described based on the examples, the present invention is not limited to the above examples in order to embody the technical idea within the scope described in the claims. Needless to say, there are various embodiments. For example, the oil seal bellows mounting structure according to the present invention can be applied to gas flow machines such as a gas compressor (gas compressor) and a vacuum pump in addition to the Stirling refrigerator.
[0050]
【The invention's effect】
According to the Stirling refrigerator according to the present invention having the above-described configuration, the oil seal bellows, which is a rod seal, is welded to the mounting ring fixed to the piston and the fixed plate fixed to the housing, respectively. Since the housing and the rod are completely sealed, it is possible to solve the problem of oil spilling, which allows oil to be applied to the inner surfaces of the compression and expansion cylinders, pistons, various heat exchangers, and piston rings. It can prevent performance degradation and durability reduction due to adhesion. As a result, an oil seal with excellent durability can be realized, and a maintenance-free and long-life Stirling refrigerator can also be realized from this aspect.
[0051]
Since a metal or resin gasket or the like is used as a seal used for the mounting portion of the upper or lower mounting ring of the oil seal bellows, the durability can be sufficiently improved.
[Brief description of the drawings]
FIG. 1 is an overall view illustrating a Stirling refrigerator to which the present invention is applied.
FIG. 2 is a diagram showing a main part of the Stirling refrigerator of FIG.
3 is a partially cutaway front view of the Stirling refrigerator of FIG. 1. FIG.
4 (a) is a view showing the main part of one embodiment of the oil seal bellows mounting structure of the present invention, and (b) and (c) are enlarged views of A and B, respectively. FIG.
5 (a) is a view showing a main part of another aspect of the mounting structure of the oil seal bellows of the present invention, and (b) and (c) are enlarged views of A and B, respectively. FIG.
6A is a view showing a main part of still another aspect of the oil seal bellows mounting structure of the present invention, and FIGS. 6B and 6C are enlarged views of A and B, respectively.
[Explanation of symbols]
1 Stirling refrigerator 2 Housing 3 Partition wall 4 Motor chamber 5 Crank chamber 6 Motor 7 Crankshafts 8 and 9 Connecting rods 10 and 11 Cross guide heads 12 and 13 Crank portions 14 and 14 'Fixing plate 15 Cylinder blocks 16, 55 and 58 bolts 17 compression cylinder 18 expansion cylinder 19 compression piston 20 high greenhouse 21 compression piston rod 22 (compression side) oil seal bellows 23 (inside heat exchanger for heat dissipation) inner cylinder 24 (in heat exchanger for cooling) inner cylinder 25 expansion piston 26 Low Greenhouse 27 Expansion Piston Rod 28 (Expansion Side) Oil Seal Bellows 29 Heat Dissipation Heat Exchanger 30 Regenerator 31 Cooling Heat Exchanger 32 Manifold 33 Communication Hole 34 (Cylinder Block) Heat Dissipation Heat Exchange Housing 35 (Heat Exchanger) Narrow groove 36 on the inner surface of the cylinder Radiating fin 37 Heat exchanger cylinder 38 Heat radiation path 39 Cover plate 40 Cooling water path 41 Inlet 42 Inlet 43 Outlet 44 Cooling heat exchange housing 45 Narrow groove 46 (of cooling heat exchange housing) Working gas flow path 47 Cooling fin 48 Buffer chamber 49 50 Pipe 51 Buffer tank 52 Oil seal bellows upper end 53 Upper mounting ring 54, 56 Piston rod flange 57 Cylindrical body 59, 65 O-ring 60 Lower end of oil seal bellow 61 Lower mounting ring 62 Upper 63 Lower mounting Ring flange 64 Groove 66, 68 Gasket 67 Lower mounting ring flange 69 Ring mounting plate 70 Inner peripheral surface 71 of fixing plate Outflow pipe 72 Inflow pipe

Claims (5)

A housing in which a motor and a crank are disposed, a cylinder fixed to the top of the housing via a fixing plate, a piston that reciprocates in the cylinder, and an interlock with the crank, and one end connected to the piston. A Stirling refrigerator having a piston rod penetrating the housing and an oil seal bellows,
The oil seal bellows has an upper end fixed to the upper mounting ring and a lower end fixed to the lower mounting ring.
The upper mounting ring is fastened to the flange portion of the piston rod via the upper sealing material,
The Stirling refrigerator, wherein the lower mounting ring is fastened to the fixed plate and / or the housing via a lower sealing material. A housing in which a motor and a crank are disposed, a cylinder fixed to the top of the housing via a fixing plate, a piston that reciprocates in the cylinder, and an interlock with the crank, and one end connected to the piston. A Stirling refrigerator having a piston rod penetrating the housing and an oil seal bellows,
The oil seal bellows has an upper end fixed to the upper mounting ring and a lower end welded to the annular mounting plate.
The upper mounting ring is fastened to the flange portion of the piston rod via the upper sealing material,
A Stirling refrigerator, wherein the annular mounting plate is welded to the fixed plate. The Stirling refrigerator according to claim 1 or 2, wherein the upper sealing material is an O-ring or a metal or resin gasket. The Stirling refrigerator according to claim 1, wherein the lower sealing material is an O-ring, or a metal or resin gasket. A plurality of the cranks are provided, and a plurality of cylinders and pistons are provided corresponding to the plurality of cranks, and the plurality of pistons reciprocate with a phase difference from each other. The Stirling refrigerator as described in the item.

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