JPH0424621B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) This invention is a regenerator with an expansion valve for liquefying the refrigerant, by pre-cooling using a Stirling cycle refrigerator and cooling by isenthalpic expansion using an expansion valve. This relates to refrigerators.

(Prior art) In recent years, with the development of superconducting equipment that utilizes the superconductivity phenomenon that occurs in certain metals near the He liquefaction temperature of 4, is gaining attention. At the development stage of conventional superconducting application technology, large-capacity Claude cycles suitable for large or medium-sized He liquefaction equipment were generally used, but recently they have been used for medical diagnostic equipment NMR-CT and magnetic levitation trains. As superconducting application devices such as these are developed, refrigerators are becoming smaller.

Therefore, the Claude cycle has been miniaturized, and a regenerator refrigeration cycle with a Joel-Thompson valve (hereinafter, commonly referred to as an "expansion valve") has come into use. An example of the latter is shown in FIG. This regenerator refrigeration cycle with an expansion valve includes a regenerator 90 and a Helium expansion valve system.
It is configured in combination with a liquefaction device 91. The regenerator refrigerator 90 consists of a compressor 92 and a displacer 93 equipped with a regenerator, and also includes:
The He liquefier 91 includes a compressor 94, heat exchangers 95a to 95c provided in multiple stages, and an expansion valve 96.
and a condensing section 97. Refrigeration equipment other than the separately placed compressors 92 and 94 is housed in a cold box 98.
A miniaturization of the refrigerator is achieved.

(Problem to be solved by the invention) However, in the above prior art, the compressors 92, 9
4 and the cold box 98, the structure becomes complicated and the entire refrigerator cannot be made compact. Therefore, the cold storage refrigerator 90
Stirling cycle system
69366, Japanese Patent Application Laid-Open No. 149958), and it is possible to house one compressor 92 in the cold box 98, but the other compressor 9
Problem 4 still remains unsolved, and the complexity of the structure cannot be resolved. Moreover, if the refrigerating capacity of the Stirling cycle system is to be increased, the regenerator refrigerator 90 will become larger, which makes it difficult to accommodate the entire refrigerator in the cold box 98.

This invention was made to solve the above-mentioned conventional problems, and an object thereof is to provide a regenerator refrigerator with an expansion valve that is simple in structure and compact.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a pair of eccentric barrels spaced apart from each other in the coaxial direction on a crankshaft that is rotationally driven by a drive machine. , a plurality of first compression pistons are arranged radially corresponding to one body, and a plurality of second compression pistons are arranged radially corresponding to the other body, and one of the compression pistons is arranged in each body. By connecting the connecting rods, a pair of radial piston drive devices is constructed. In addition, a plurality of displacers are arranged concentrically with the crankshaft, and a cam groove that is displaceable in the axial direction of the crankshaft is provided on the outer periphery of a cam member fixed to one end of the crankshaft. A displacer drive device is constructed by inserting a drive body and connecting a rod for reciprocating the displacer in the axial direction of the crankshaft to the drive body. The shape of the cam groove is set so that the phase of the corresponding displacer can advance approximately 90 degrees with respect to the first compression piston. Further, the expansion valve of the refrigerant liquefaction device communicates with the discharge port of the compression chamber on the second compression piston side via the heat exchanger and the cold head of the displacer. Further, the condensing section has an inlet side communicating with the expansion valve, and an outlet side communicating with the suction port of the compression chamber via a heat exchanger.

(Function) According to the present invention, the radial expansion valve system and the Stirling cycle refrigerator system piston drive device are connected in the axial direction of the crankshaft, and each piston drive device is driven by a single drive device. Therefore, the structure is simplified and the size is reduced. Therefore, all the refrigeration equipment, including the expansion valve system and the Stirling cycle refrigerator system, can be easily housed in the cold box.

In addition, one radial type piston drive device,
A Stirling cycle refrigerator was constructed by combining the crankshaft of this piston drive device with a displacer drive device having a plurality of displacers arranged concentrically. Even if the number of displacers is increased, the overall size of the refrigerator can be avoided.

Furthermore, since a radial piston drive mechanism is adopted, most of the gas compression load is canceled out on the crankshaft, making it possible to maintain the balance of compression forces relatively easily. Therefore, the load on the bearing section that supports the crankshaft can be reduced, so that the casing and bearing section of the crankshaft can be made more compact as a whole.

In addition, since the compression pistons are arranged radially,
Even if the piston diameter is increased, the overall size of the device does not increase. Therefore, the output can be easily increased.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a system diagram of a regenerator refrigerator with an expansion valve. In the figure, a regenerator refrigerator 100 with an expansion valve in a cold box 75 is configured by combining a Stirling cycle refrigerator 1 and an expansion valve-based refrigerant liquefaction device 50, and the drive shaft includes:
Basically, a radial expansion valve piston drive device 51, a radial Stirling cycle refrigerator piston drive device 2, and a displacer drive device 3 are connected in this order.

As shown in FIG. 2, the Stirling cycle refrigerator 1 includes a drive machine 6.
is connected to the crankshaft 4 via a reduction gear 5. The speed reducer 5 is, for example, a planetary gear mechanism or a bevel gear mechanism. The reducer 5 and the driver 6 are
The system has an airtight structure to prevent the working gas from leaking. The crankshaft 4 vertically passes through an airtight crankcase 7, and is rotatably supported within the crankcase 7 by low vapor pressure, grease-sealed roller bearings 8a to 8d.

The crankshaft 4 is provided with a pair of body parts 9a, 9b spaced apart in the axial direction (vertical direction in FIG. 2), each body part 9a, 9b having a larger diameter than the crankshaft 4, Moreover, they are each eccentric with respect to the crankshaft 4. Expansion valve system piston drive device 51
is provided corresponding to the body portion 9b on the reducer 5 side,
Further, the Stirling cycle refrigerator system piston drive device 2 is provided corresponding to the body portion 9a on the side of the displacer drive device 3. Each piston drive device 2, 51 has a similar configuration, and corresponding parts are given the same reference numerals and will be described below.
That is, an outer ring 11 is rotatably fitted into the body parts 9a, 9b via a low vapor pressure, grease-sealed roller bearing 10. First and second compression pistons 17a, 17 are provided on the outer peripheral surface of the outer ring 11.
A sliding bearing 13a of the connecting rod 13 connected to b is in sliding contact. A non-lubricated material is fixed to the sliding bearing 13a with a constant thickness. The non-lubricated material is selected to have good sliding properties and wear resistance, such as a polymer bearing material or a sintered bearing material. Note that 12 is an oil seal.

The connecting rod 13 extends radially in the radial direction of the outer ring 11.
are arranged. A pair of guide rings 14a and 14b made of a lubricant-free material are fitted into the lower end flange portion 13b of each connecting rod 13. The guide rings 14a, 14b maintain the contact state between the sliding bearing 13a of each connecting rod 13 and the outer ring 11, and prevent the connecting rod 13 from sliding in the direction indicated by arrow A. In addition, the guide ring 14
a, 14b, the outer ring 11 and the sliding bearing 13a
The sliding friction heat is transmitted to the crankcase 7, and the low temperature near the sliding bearing 13a is maintained.

The connecting rod 13 on the body 9a side is connected to a first compression piston 17a via a spherical bearing 19a, and the connecting rod 13 on the body 9b side is connected to a second compression piston 17b via a spherical bearing 19b. There is. 1st
As shown in FIG. 3, the compression pistons 17a are individually accommodated in first cylinders 18a that protrude radially from the crankcase 7 at equal intervals in the circumferential direction, and as shown in FIG. The second compression piston includes a second cylinder 1 radially protruding from the crankcase 7 corresponding to the first cylinder 18a.
8b. 2nd cylinder 1
8b, a third cylinder 18c having a relatively small diameter is connected coaxially with the second cylinder 18b,
Third compression piston 17c in third cylinder 18c
is connected to the second compression piston 17b via the piston rod 15. Second cylinder 18b
The compression chamber 20b therein is airtightly shielded from the rear chamber 21c inside the adjacent third cylinder 18c by a shielding portion 85 through which the piston rod 15 slidably passes and a seal ring 54.

The spherical bearings 19a and 19b are made of a polymer-based or sintered metal-based non-lubricated material, and the first
The piston ring 22 and rider ring 23 of the ~3rd compression pistons 17a, ~17c are made of a synthetic resin-based non-lubricated material. Further, each compression piston 17a, 17b has the guide ring 14a, 1
A scraper ring 24 having a dustproof function is attached to prevent dust from entering the compression chambers 20a, 20b due to wear of the slide bearings 13a and 4b.

The compression chambers 20a to 20c of the first to third cylinders 18a to 18c and the back chambers 21a and 21b in the crankcase 7 are each filled with He gas as a refrigerant at a predetermined pressure. During operation, a compression load that overcomes the inertial force of the compression pistons 17a to 17c and the frictional force of the piston ring 22 and rider ring 23 acts on each compression chamber 20a to 20c, and the connecting rod 13 and outer ring 11 They are in contact with that compressive load. In addition,
25a and 25b are cooling water passages for the cylinders 18a and 18b, and the cooling water absorbs the compression heat of the He gas, the sliding friction heat of the rings 22 and 23, and the sliding friction heat of the spherical bearings 19a and 19b, respectively. Ru.

The second cylinder 18b has a first suction port 55 and a first discharge port 56 facing the compression chamber 20b, and the third cylinder 18c has a second suction port 57 and a first discharge port 56 facing the compression chamber 20c. Second discharge port 5
8 is drilled. The first discharge port 56 and the second suction port 57 communicate with each other via a communication pipe (not shown). In addition, 80 and 81 are suction valves, and 8
2 and 83 are discharge valves.

The second discharge port 58, as shown in FIG.
The first suction port 55 communicates with the inflow port 62 of the condensing section 61 via the outward path 59 of the expansion valve system, and the first suction port 55 communicates with the outflow port 63 of the condensing section 61 via the return path 60 of the expansion valve system. . The outbound route 59 and the return route 60 are the first
~3rd countercurrent heat exchangers 64 to 66, respectively, and furthermore, in the middle of the outward path 59, a cold head 47 of the displacer 41, which will be described later, is connected.
Cooling pipes 67 and 68 guided to the pipes a and 47b and a Joel-Thompson valve 69 which is an expansion valve are interposed. Heat exchangers 64-66 and cooling pipes 67, 68
In this step, approximately 300㎓ of He gas compressed by the second compression piston 17b (Fig. 2) is sequentially cooled down to approximately
It plays the role of lowering the temperature to 15㎜ and supplying it to the expansion valve 69. Further, the expansion valve 69 plays the role of extremely lowering the temperature of the pre-cooled He gas to a level of 4㎜ by isenthalpic expansion and supplying it to the condensing section 61 . Further, the condensing section 61 plays the role of storing the liquid He 52 condensed by the cryogenic temperature reduction of the expansion valve 69 and guiding the He gas vaporized by the thermal load from the superconducting coil 72 to the return path 60 of the expansion valve system. Superconducting coil 7 as a cooled object
2 is interposed in the middle of a pipe 71 that transports the refrigeration output of liquid He 52.

Next, the configuration of the displacer drive device 3 will be explained. A cam member 30 coaxial with the crankshaft 4 is provided at the upper end of the crankshaft 4 in FIG. A key 31 is provided between the crankshaft 4 and the cam member 30 to make the rotational movements of the two the same.
is inserted. On the outer peripheral surface of the cam member 30,
A cam groove 32 with a rectangular cross section extending in the circumferential direction is formed. The cam groove 32 is curved in a sinusoidal shape in the circumferential direction, and four roller-shaped driving bodies 33 are inserted into the cam groove 32 at equal intervals in the circumferential direction. . Each drive body 33 is rotatable about an axis perpendicular to the crankshaft 4 by a grease-sealed roller bearing (not shown), and is connected to four rods 34 concentrically with the crankshaft 4 by bolts and bolts. They are individually fastened by nuts 49. Each rod 34 extends coaxially with the crankshaft 4 and is reciprocatably supported within the airtight casing 28 by low vapor pressure, grease-sealed bearings 36a, 36b.

Each rod 34 is individually connected to each displacer 41 in four displacer cylinders 40 extending coaxially with the rod 34.
The displacer 41 has a relatively large diameter first displacer 41 connected to the tip of the rod 34.
a, and a relatively small-diameter second displacer 41b connected to the first displacer. 1st
An airtight back chamber 42 is provided at the connection between the displacer 41a and the rod 34, and this back chamber 42 is connected to the compression chamber in the compression piston cylinder 18 via a passage 43 and a heat exchanger 44. It is connected to 20. The heat exchanger 44 is configured by incorporating a plurality of water cooling pipes.

Inside the first displacer 41a, a first regenerator 38a made up of layered wire mesh (cold storage material) is incorporated, and inside the second displacer 41b, lead particles (cold storage material) are incorporated. A second regenerator 38b filled with water is incorporated. 1st displacer 4
An airtight first expansion chamber 46a is provided at the connection portion between 1a and the second displacer 41b.
In the vicinity of this first expansion chamber 46a, an annular first cold head 47a that communicates with all of the first expansion chambers 46a of the displacer cylinder 40 is provided. In addition, the second displacer 41b
An airtight second expansion chamber 46b is provided at the tip of the displacer cylinder 40.
A second annular cold head 47b is provided which communicates with all of the cold heads 47b. The first and second expansion chambers 46a, 46b are connected to the first and second regenerators 38.
a, 38b to the rear chamber 4 on the rod 34 side.
It is connected to 2.

Next, the operations of the expansion valve system piston drive device 51 and the refrigerant liquefaction device 50 will be explained.

First, when the drive device 6 shown in FIG. 2 is operated, the crankshaft 4 is reduced to a constant rotational speed by the reduction gear 5 and driven to rotate. The rotational motion of one eccentric body portion 9b of the crankshaft 4 is converted into a reciprocating motion of the connecting rod 13 via the roller bearing 10 and the outer ring 11. Due to the eccentricity of the body portion 9b, the second and third compression pistons 17b and 17c reciprocate within the second and third cylinders 18b and 18c, respectively.
At this time, first, the return path 60 of the expansion valve system (Fig. 1)
He gas of 1 to 2 atm is sucked into the second compression chamber 20b by the first suction valve 80, raised to a predetermined intermediate pressure by the second compression piston 17b, and then released to the first discharge by the first discharge valve 82. It is discharged from the outlet 56. The discharged He gas is sucked into the third compression chamber 20c by the second suction valve 81 via a communication pipe (not shown), and the discharge pressure is increased by the third compression piston 17c.
The pressure is increased to 20 atm, and the second discharge valve 83 discharges from the second discharge port 58 into the outgoing path 59 of the expansion valve system shown in FIG. The high temperature, high pressure He gas discharged into the outgoing path 59 is transferred to the first to third heat exchangers 64 to 66.
The temperature is lowered step by step in the cooling pipes 67,
At 68, the cold head 47 of the displacer 41
A, 47b refrigeration output is obtained, and finally, 15〓
The temperature is lowered to K. Pre-cooled like this
The He gas is cryogenically cooled to a level of 4〓 by isenthalpic expansion in the expansion valve 69, and then
is directed into the superconducting coil 72 to produce refrigeration power for the superconducting coil 72. The He gas vaporized by the heat load of the superelectric coil 72 is separated from the liquid He 52 in the condensing section 61 and guided to the return path 60 of the expansion valve system, and then
~ The third heat exchangers 64 to 66 remove heat from the He gas on the outgoing path 59 side, and turn it into high-temperature gas,
is sucked into the second compression chamber 20b by the first suction valve 80, and the above-described series of compression, preliminary cooling, and cryogenic steps are repeated.

Next, the operations of the Stirling cycle piston drive device 2 and the displacer drive device 3 will be explained.

The rotational movement of the eccentric body 9a of the crankshaft 4 in FIG. 2 is also converted into a reciprocating movement of the connecting rod 13 via the roller bearing 10 and the outer ring 11. Torso 9
Due to the eccentricity of a, the four first compression pistons 17a
reciprocate within the first cylinder 18a with a phase difference of 90 degrees.

On the other hand, the rotational torque of the crankshaft 4 is transmitted to the cam member 30 and converted into reciprocating motion of the rod 34 via the drive body 33 inserted into the cam groove 32 of the cam member 30. Due to the sinusoidal shape of the cam groove 32, the four displacers 41 move toward the cylinder 40 90 degrees ahead of the phase of the corresponding compression piston 17.
Each moves back and forth inside.

Next, four steps per cycle of the Stirling cycle refrigerator 1, that is, an isothermal compression step, an isovolume step,
The isothermal expansion process and the isovolume process will be explained.

First, in the isothermal compression process, from a state in which the displacer 41 is located at the upper end of the displacer cylinder 40 and the first compression piston 17a is located at the lower end of the compression piston cylinder 18a, the first
When the compression piston 17a rises, the first compression chamber 2
The He gas in Oa is compressed and flows into the back chamber 42 through the heat exchanger 44 and passage 43. At this time, a part of the generated gas compression heat is absorbed by the water-cooled cylinder 18, and the remaining compression heat is absorbed by the heat exchanger 44. Ideally, this is an isothermal compression process.

Next, in the equal volume process, the displacer 4
1 descends, the He gas in the back chamber 42 passes through the first regenerator 38a and flows into the first expansion chamber 46a, and some He gas also flows into the second regenerator 38a.
8b and flows into the second expansion chamber 46b.
At this time, He gas is transferred to the first and second regenerators 3
When passing through the regenerators 8a and 38b, the regenerator absorbs heat and is cooled, and the pressure also decreases, becoming a low-temperature gas at a predetermined pressure in the first and second expansion chambers 46a and 46b. This is an isovolumic change with a constant volume.

Next, in the isothermal expansion step, when the first compression piston 17a descends, the He gas in the first and second expansion chambers 46a, 46b is expanded and cooled. At this time, heat is removed from the first and second cold heads 47a and 47b, and the He gas eventually undergoes isothermal expansion at a constant temperature. The amount of heat taken by the He gas is the refrigeration output of the refrigerator 1.

Next, in the equal volume process, the displacer 4
1 rises, the first and second expansion chambers 46a,
The He gas in 46b is transferred to the first and second regenerators 3
8a, 38b, flows into the rear chamber 42 on the rod 34 side, and further flows into the first compression chamber 20a through the heat exchanger 44. At this time, He
The gas itself becomes high in temperature while cooling each of the regenerator materials in the first and second regenerators 38a and 38b, and its pressure also increases. This is an isovolumic change with a constant volume.

By repeating the above series of operations, continuous refrigeration output can be obtained in the first and second cold heads 47a and 47b.

In the above configuration, since the Stirling cycle compressor and the expansion valve compressor are configured by a pair of flat radial piston drive devices 2 and 51, the space occupied by each compressor in the axial direction of the crankshaft 4 can be narrowed down. This allows the entire refrigerator to be downsized. In addition, each piston drive device 2, 51 is connected to the crankshaft 4.
Since the piston drive devices 2 and 51 are directly connected in the coaxial direction, each piston drive device 2, 51 can be driven by a single drive device 6. Furthermore, since a Stalin cycle system is adopted in which the crankshaft 4 is directly connected to the displacer drive device 3, the structure is simplified and downsized. Therefore, the refrigerator 100 with an expansion valve according to this invention can be easily accommodated in the cold box 75. This eliminates the need for piping between the conventional separately installed compressor and the cold box, so the structure is not complicated and the refrigerator as a whole can be made more compact.

In addition, a Stirling cycle refrigerator is manufactured by combining a radial type piston drive device 2 and a displacer drive device 3 having a plurality of displacers 41 arranged concentrically with the crankshaft 4 of the piston drive device 2. 1, the first compression piston 17a is used to improve the refrigerating capacity.
Even if the number of displacers 41 is increased, the overall size of the refrigerator can be avoided.

In addition, the first
Since the second compression pistons 17a and 17b are arranged radially, the compression piston cylinder 18
Most of the gas pressure loads in a and 18b are canceled out, and the compressive load on the bearing portion that supports the crankshaft 4 can be reduced. Therefore, the bearing portion and the crankcase 7 can be made more compact.

Also, since the gas pressure load is canceled out, the first
Also, the diameter of the second compression pistons 17a, 17b can be increased, thereby increasing the output. Moreover, since the compression piston cylinders 18a and 18b are provided radially,
Even if the cylinder diameter is increased, the size of the entire refrigerator in the axial direction (vertical direction in FIG. 2) does not increase.

Further, in this embodiment, the expansion valve system piston drive device 51 is connected to the second and second compression pistons 17.
b, 17c, He gas in the expansion valve system is
By compressing in stages, the compression ratio of He gas can be increased. As a result, even if the suction pressure is as low as, for example, 1 to 2 atm, a discharge pressure of 20 atm can be obtained, and the condensation efficiency in the expansion valve system can be increased.

In addition, since the inside of the system is made oil-free by the method described below, the service life is extended without oil supply and the structure is simplified. Even if it enters the compression chambers 20a, 20b, contamination inside is prevented. This achieves prevention of contamination of the regenerator material, improvement of heat conductivity, and reduction of pressure loss, thereby improving the performance and reliability of the refrigerator 1. That is, the eccentric body portions 9a, 9b of the crankshaft 4
has a fairly high circumferential speed, but since grease-sealed roller bearings 10 with a small coefficient of friction are provided on the outer peripheral surfaces of the bodies 9a and 9b, the frictional work in these parts can be significantly reduced. Furthermore, roller bearing 10
As a result, the outer ring 11 hardly rotates, so that the relative movement of the sliding bearing 13a of the connecting rod 13 with respect to the outer peripheral surface of the outer ring 11 can be reduced. Therefore, the sliding bearing 13a can be made of a non-lubricated material.

Furthermore, since the cam member 30 is used as a method of driving the displacer 41, the cam member 30
By appropriately changing the shape of the cam groove 32 within a range that does not impede the reciprocating motion of the drive body 33 and the rod 34, it is possible to easily achieve the most thermodynamically preferable reciprocating motion of the displacer 41.

Further, since the piston drive device 2 and the displacer drive device 3 are connected by the key 31 provided between the crankshaft 4 and the cam member 30,
The phase difference between each reciprocating motion of the first compression piston 17a and the displacer 41 can be arbitrarily selected.
This phase difference greatly affects the refrigeration output. In an ideal state, the phase difference is 0 degrees and the refrigeration output is zero,
Refrigeration output is maximum when the phase difference is 90 degrees. but,
In reality, it is 90 degrees, which is slightly off 90 degrees due to pressure loss and other factors.
The optimum value exists near the degree.

In the above embodiment, a non-lubricating system is adopted, but an oil seal mechanism may be used that supplies lubricating oil to the bearing and prevents the refrigerant from being contaminated by oil.

Further, instead of the cylindrical cam member 30 of the displacer drive device 3, a rotating swash plate may be used.

(Effects of the Invention) As explained above, according to the present invention, a radial expansion valve system and a Stirling cycle refrigerator system piston drive device are connected coaxially to the crankshaft, and each piston is driven by a single drive machine. Since the drive device is used, the structure is simplified and the size is reduced. Therefore, all the refrigeration equipment including the expansion valve system and the Stirling cycle refrigerator system can be easily accommodated in the cold box, and a compact refrigerator with a simple structure can be realized.

In addition, since the refrigerator was constructed by combining a radial piston drive device and a displacer drive device having a plurality of displacers arranged concentrically with the crankshaft of the piston drive device, the refrigerating capacity was Even if the number of compression pistons and displacers is increased to improve the efficiency, it is possible to avoid increasing the size of the refrigerator as a whole.

Additionally, since the compression pistons are arranged radially, most of the gas pressure loads in each cylinder are offset. Therefore, the bearing portion and the casing can be made lightweight and compact. Furthermore, even if the cylinder diameter is increased in order to increase the output, the device is prevented from becoming complicated or large.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a regenerator refrigerator with an expansion valve according to the present invention, Fig. 2 is a sectional view of main parts of the regenerator refrigerator with an expansion valve, and Fig. 3 is a diagram taken along the - line in Fig. 2. The sectional view, FIG. 4, is a system diagram of a conventional refrigerator. DESCRIPTION OF SYMBOLS 1... Stirling cycle refrigerator, 2... Radial piston drive device, 3... Displacer drive device, 4... Crankshaft, 6... Drive machine, 9a, 9b... Body, 11... Outer ring , 13...
...Connecting rod, 17a, 17b...Compression piston, 3
0... Cam member, 32... Cam groove, 33... Drive body, 34... Rod, 38a, 38b... Regenerator, 41... Displacer, 42... Back chamber,
44, 64-66... Heat exchanger, 46a, 46b
...Expansion chamber, 47a, 47b...Cold head, 55...Suction port, 58...Discharge port, 61...
Condensing section, 69...expansion valve, 100...refrigerator with expansion valve.

Claims (1)

[Claims] 1. A first refrigerant compressed by a first compression piston is cooled in an expansion chamber through a regenerator in a displacer, and a second refrigerant compressed by a second compression piston is cooled. In a regenerator refrigerator with an expansion valve, which pre-cools the refrigerant with the first refrigerant and then passes it through an expansion valve to bring it to a cryogenic temperature through isenthalpic expansion, the crankshaft, which is rotationally driven by a drive machine, is provided with an interval in the coaxial direction. A pair of eccentric body parts are provided, a plurality of first compression pistons are arranged radially in correspondence with one body part, and a plurality of second compression pistons are arranged radially in correspondence with the other body part. A pair of radial piston drive devices each having a connecting rod of each compression piston connected to each body, and a plurality of displacers are disposed concentrically with the crankshaft, and one end of the crankshaft is arranged with a plurality of displacers. A cam groove that is displaceable in the axial direction of the crankshaft is provided on the outer periphery of the cam member fixed to the cam member, and a rod that reciprocates the displacer in the axial direction of the crankshaft is inserted into the drive body inserted into this cam groove. a displacer drive device connected to the first compression piston and configured to set the shape of the cam member so that the phase of the corresponding displacer advances approximately 90 degrees with respect to the first compression piston; An expansion valve communicates with the discharge port of the compression chamber via a heat exchanger and a cold head of the displacer, an inflow side communicates with the expansion valve, and an outflow side communicates with the suction port of the compression chamber via the heat exchanger. 1. A regenerative refrigerator with an expansion valve, comprising: a refrigerant liquefaction device including a condensing section and a refrigerant liquefaction device.