JP2726789B2 - Cool storage refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative refrigerator used for a superconducting magnet applied to, for example, a magnetic resonance diagnostic imaging apparatus.

[0002]

2. Description of the Related Art FIG. 23 is a schematic cross-sectional view showing an example of a conventional regenerative refrigerator. In FIG. 23, reference numeral 1 denotes a first stage, a second stage and a second stage obtained by cutting stainless steel into a cylindrical shape and having different diameters. A three-stage cylinder 1a, 1b, 1c is connected to form a three-stage cylinder, and a displacer 2 is slidably disposed in the cylinder 1. The displacer 2 is formed of, for example, a phenol laminated tube. The first, second and third stage displacers 2a, 2b, 2c are
As shown in FIG. 4, the universal joint 3 and the fixed pin 4 are configured to be rotatably connected to each other.

[0005] Reference numeral 5 denotes first, second and third stage regenerators 5a, 5b and 5c in which regenerator material is filled in first, second and third stage displacers 2a, 2b and 2c, respectively.
Here, the first-stage regenerator 5a is provided with a copper wire mesh, the second-stage regenerator 5b is provided with lead balls, and the third-stage regenerator 5b.
The stage regenerator 5c is filled with GdRh as a regenerative material.

[0004] Reference numerals 6, 7 and 8 are disposed between first, second and third stage cylinders 1a, 1b and 1c and first, second and third stage displacers 2a, 2b and 2c, respectively. The first, second and third stage seals provided. Here, as shown in, for example, FIG. 25, the first-stage seal 6 forms a circumferential annular groove 61 on the outer peripheral surface on the high-temperature side of the first-stage displacer 2a.
A so-called cap seal structure is adopted in which the ring 63 and the ring 63 are disposed in the annular groove 61 and hermetically sealed by the elastic force of the O-ring 63. Although not shown,
The scotch yoke shaft of the driving means for reciprocating the displacer 2 also has the above cap seal structure. In addition, the second and third stage seals 7, 8 are shown in FIG.
6 (a) and 6 (b), a circumferential annular groove 71 is formed on the outer peripheral surface on the high temperature side of the second and third stage displacers 2b and 2c, A piston ring 72 and a backup ring 73 are provided in the annular groove 71, and the backup ring 73
Airtight sealing by the elastic force of

[0005] Reference numerals 9, 10 and 11 denote first, second and third stages respectively disposed on the outer peripheral surfaces of the lower end portions of the first, second and third stage cylinders 1a, 1b and 1c. This is a three-stage heat stage, and a high heat conductive material, for example, copper is used for these heat stages. 12 is the first
Stage expansion chamber, 13 is a second stage expansion chamber, 14 is a third stage expansion chamber,
15 is a helium gas, 16 is a helium compressor, 17 is an intake valve for introducing helium gas 15 compressed by the helium compressor 16, 18 is an exhaust valve for discharging helium gas 15, 19 is a drive motor, and 20 is a drive motor This is a driving mechanism that converts the rotation of 19 into a linear motion and operates the intake valve 17 and the exhaust valve 18 in synchronization with this motion.

[0006] The regenerative refrigerator configured as above operates as follows. First, in a state where the first, second and third-stage displacers 2a, 2b and 2c are at the lowermost end, the intake valve 17 is open and the exhaust valve 18 is closed, the first and second stages are displaced. And the third-stage expansion chambers 12, 1
A high-pressure helium gas 15 compressed by a helium compressor 16, which is a helium gas compression means, is introduced into the insides 3 and 14 to be in a high-pressure state.

Next, the first-stage, second-stage and third-stage displacers 2a, 2b, and 2c move upward, and accordingly, high-pressure helium gas 15 is supplied to the first-stage, second-stage, and third-stage regenerators 5a. , 5b, 5c are introduced into the first, second and third stage expansion chambers 12, 13, 14. During this time, the intake and exhaust valves 17, 18 do not move. The high-pressure helium gas 15 is cooled to a predetermined temperature by each regenerator material when passing through the first regenerator 5a, the second regenerator 5b, and the third regenerator 5c. Furthermore, the first
Stage, second stage and third stage displacers 1a, 1b, 1
When c reaches the uppermost end, the intake valve 17 closes, the exhaust valve 18 opens, and the high-pressure helium gas 15 expands to the low-pressure portion, causing refrigeration. At this time, helium gas 15
Becomes a low-temperature low-pressure gas.

Next, the first, second and third stage displacers 2a, 2b and 2c move downward, so that the low-temperature and low-pressure helium gas 15 is cooled by the first, second and third stage regenerators. The gas is exhausted from the exhaust valve 18 through the vessels 5a, 5b, 5c. At this time, the low-temperature and low-pressure helium gas 15 is supplied to the first, second and third regenerators 5a and 5a.
After cooling the cold storage materials b and 5c, the process returns to the helium compressor 16.

Thereafter, with the volumes of the first, second and third stage expansion chambers 12, 13, and 14 minimized, the exhaust valve 18 is closed, the intake valve 17 is opened, and the helium compressor 16 The compressed high-pressure helium gas 15 is introduced, and the first, second and third stage expansion chambers 12, 13, 1
The pressure of 4 changes from low pressure to high pressure.

The helium gas 15 at a high pressure, for example, 20 bar, is supplied to the first stage regenerator 5a at 60K (Kelvin).
Is cooled to 15K by the second-stage regenerator 5b, further cooled by the third-stage regenerator 5c, and guided to the third expansion chamber 14. For example, if the regenerator material of the third-stage regenerator 5c is lead, the specific heat is smaller than the helium gas 15, so the helium gas 15 is not sufficiently cooled and is guided to the third-stage expansion chamber 5c,
The temperature of the expansion chamber rises to cause a loss, and 6.5K
Although only the ultimate temperature can be obtained, since GdRh is used as the cold storage material of the third stage regenerator 5c, the specific heat is larger than that of lead and the loss is smaller, and the ultimate temperature of 5.5K is obtained.

As described above, the temperature of the helium gas 15 in the first, second and third stage expansion chambers 12, 13 and 14 is:
First stage, second stage and third stage cylinders 1a, 1b, 1c
Through the first stage, the second stage, and the third stage heat stages 9, 10, and 11, for example, applied to cooling of a superconducting magnet.

Next, an application example of the above-mentioned conventional regenerative refrigerator will be described. FIG. 27 is a partially cutaway perspective view showing an example of a conventional superconducting magnet. In the drawing, reference numeral 21 denotes a cylindrical superconducting coil, which is immersed in liquid helium 23 filled in a helium tank 22. , Kept at cryogenic temperatures. Numeral 24 denotes a vacuum tank arranged so as to surround the helium tank 22.
4 and the helium tank 22 are evacuated and insulated. 25 is a second heat shield, 26 is a first heat shield, and these first and second heat shields 26 and 25 are
The helium tank 22 is disposed between the helium tank 22 and the vacuum tank 24 so as to surround the helium tank 22 in a coaxial cylindrical shape.
To reduce heat intrusion.

FIG. 23 is attached to the end face of the vacuum chamber 24 substantially in parallel with the axial direction of the superconducting magnet 21.
, 28 is an iron magnetic shield disposed around the vacuum chamber 24 together with an iron magnetic shield flange 29, 30 is a bore, 31 is a port 3
2, a pressure release valve, a mounting foot 33 for the superconducting magnet, and a pressure controller 34 for controlling the pressure in the helium tank 22.

Next, a mounting structure of the regenerative refrigerator 27 will be described with reference to FIG. An L-shaped pipe 35 made of stainless steel is provided above the helium tank 22 so that one end faces the atmosphere of the helium gas evaporated in the helium tank 22. A stainless-steel refrigerator mounting cylinder 36 is mounted on the end surface of the vacuum chamber 24 substantially in parallel with the axial direction of the superconducting coil 21. The L-shaped tube 35 and the refrigerator mounting cylinder 36 are connected by a bellows 37. The refrigerator mounting cylinder 36 is provided with first and second copper heat stages 38 and 39, which are thermally connected to the first and second heat shields 26 and 25, respectively. In addition, the first and second heat stages 3
First and second radiant covers 4 made of copper so as to cover thermal connection portions between the first and second heat shields 26 and 25 and the first and second heat shields 26 and 25.
0 and 41, and a stainless steel sealing plate 42
Is attached to the vacuum chamber 24 to reduce heat intrusion from the outside.

The regenerative refrigerator 27 is inserted and mounted in a refrigerator mounting cylinder 36 such that the third heat stage 11 is exposed to a helium gas atmosphere drawn into the L-shaped tube 35. At this time, the refrigerator-side heat conductor 43 attached to the first and second heat stages 9 and 10 and the mounting position of the first and second heat stages 38 and 39 of the refrigerator mounting cylinder 36 are set. The refrigerator-mounted cylinder-side heat conductor 44 disposed on the inner wall surface is thermally connected to each other.

In the superconducting magnet constructed as described above, since the regenerative refrigerator 27 is mounted substantially parallel to the axial direction of the superconducting coil 21, the gap between the first heat shield 26 and the second heat shield 25 and First heat shield 26
The length of the reciprocating movement of the displacer 2 necessary for achieving the cooling performance of the regenerative refrigerator 27 can be secured in the axial direction of the superconducting coil 21 without increasing the gap between the disposer 2 and the vacuum tank 24 without increasing the gap between the superconducting coil 21 and the apparatus. The size can be reduced and the size can be reduced.

The first and second heat stages 9, 1 cooled to a predetermined temperature by the operation of the regenerative refrigerator 27 are provided.
0, the refrigerator-side heat conductor 43, the refrigerator-mounting cylinder-side heat conductor 44, the first stage and the second stage heat stage 3,
8 and 39, the first and second heat shields 26 and 25 are cooled, heat intrusion from the outside is reduced, and the third heat stage 11 separates the L-shaped tube 3 from the helium tank 22.
The helium gas drawn out into the helium gas 5 is reliquefied and returned to the helium tank 22, so that it can operate stably and reduce the consumption of expensive helium.

[0018]

As described above, the conventional regenerative refrigerator has a first-stage, a second-stage and a third-stage seal 6 as described above.
7 and 8 are configured with a cap seal structure composed of the Teflon seal 62 and the O-ring 63 and a seal structure composed of the piston ring 72 and the backup ring 73, and particularly when the regenerative refrigerator 27 is mounted horizontally. However, when the displacer 2 is reciprocated, the outer peripheral surface of the displacer 2 and the inner peripheral surface of the cylinder 1 rub against each other due to their own weight, generating heat, thereby deteriorating the cooling performance.

The Teflon seal 62 and the piston ring 72 are connected to the O-ring 63 and the backup ring 7.
3 is pressed against the inner peripheral surface of the cylinder 1 to ensure airtightness, so that when the displacer 2 reciprocates, the Teflon seal 62 and the piston ring 72
However, there is also a problem that the rubber rubs against the cylinder 1 and wears, thereby impairing airtightness.

Since the first, second and third stage displacers 2a, 2b and 2c are rotatably connected to each other via the universal joint 3 and the fixing pin 4, there is no play in the axial direction. In the initial stage of cooling, the cylinder 1 is cooled faster than the displacer 2 and thermally contracts more, so that the cylinder 1 and the displacer 2 collide in the axial direction, and in the worst case, breakage. There was also a problem of doing it.

Further, since the third-stage regenerator 5c is formed by uniformly filling the regenerator material made of GdRh, which is a rare earth metal alloy, the thermal conductivity of the regenerator material is poor and the regenerative efficiency cannot be improved. There were also issues.

Further, since the helium gas 15 directly flows into the regenerator 5 from the gas inflow end of the displacer 2,
There is also a problem that the water vapor and oil vapor contained in the helium gas 15 sent through the helium compressor 16 are accumulated in the regenerator 5 to lower the regenerative efficiency.

In addition, since the regenerator material is uniformly filled in the regenerator 5, the flow rate of the helium gas 15 is reduced, the heat transfer efficiency is reduced, and the regenerative efficiency is reduced.

Since the regenerator 5 is filled with one kind of regenerative material, only a specific heat peak at a specific temperature exists in the temperature range from the high temperature side to the low temperature side of the regenerator 5, and the regenerator There was also a problem that efficiency could not be improved.

The third-stage regenerator 5c is formed by filling a regenerator material made of a rare earth metal alloy, GdRh,
Further, since the third-stage cylinder 1c is made of stainless steel, the regenerator material is a magnetic material. For example, when the regenerator material is applied to a superconducting magnet or the like, the external magnetic field is disturbed by the reciprocating movement of the regenerator material. There is also a problem that the uniformity of the magnetic field is impaired, and further, an electromagnetic force is generated in the cold storage material by the external magnetic field, and the displacer 2 is rubbed by the cylinder 1 to generate heat, thereby deteriorating the cooling performance.

The first, second and third cylinders 1a, 1b, 1 made by cutting stainless steel.
Since c is used, there is also a problem that the processing cost is high and the refrigerator becomes expensive.

Further, since the heat stage is mounted on the outer peripheral surface of the cylinder 1, when the heat stage is mounted on the superconducting magnet substantially in the axial direction of the superconducting coil 21, the inner peripheral surface of the refrigerator mounting cylinder 36 and the cylinder 1 There is also a problem that the gap with the outer peripheral surface becomes large, and helium gas filling the gap through the L-shaped tube 35 generates heat convection due to a temperature difference in the axial direction of the cylinder 1 and lowers cooling efficiency. there were.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to improve the cold storage efficiency, improve the cooling performance, and obtain an inexpensive cold storage refrigerator. And

[0029]

According to a first aspect of the present invention, there is provided a regenerative refrigerator in which at least one of an inner peripheral surface of a cylinder and an outer peripheral surface of a displacer is coated with a low-friction material. An annular groove is provided in the direction .

Further, in the regenerative refrigerator according to the second aspect of the invention , the annular groove in the circumferential direction is formed on one side of the outer peripheral surface of the scotch yoke shaft of the driving means and the inner peripheral surface of the receiving portion of the scotch yoke shaft. The seal portion of the Scotch yoke shaft is formed by loosely fitting a ring-shaped seal body having a small gap with the other side of the outer peripheral surface of the Scotch yoke shaft and the inner peripheral surface of the receiving portion into the annular groove. It was done.

Further, in the regenerative refrigerator according to the third aspect of the present invention , a plurality of displacers are connected in the axial direction of the displacer by a joint made of a permanent magnet.

Further, in the regenerative refrigerator according to the fourth aspect of the present invention , an adsorbent is disposed between the gas inlet end of the displacer and the regenerator.

Further, in the regenerative refrigerator according to the fifth invention , at least a regenerator built in one of the plurality of displacers is provided with a partition plate at an angle with respect to the axis of the regenerator. A different type of cold storage material is filled in each partition space formed by the partition plate.

The regenerative refrigerator according to the sixth aspect of the present invention uses a drawing tube for the cylinder.

In the regenerative refrigerator according to the seventh aspect of the present invention , a drawing tube is used for each of a plurality of cylinders, and a heat stage is formed from a cylindrical portion and a truncated hollow conical portion. Insert and join the cylindrical part inside
The other cylinder is inserted and joined in the truncated cone, and a plurality of cylinders are hermetically connected by a heat stage.

The regenerative refrigerator according to an eighth aspect of the present invention is the regenerative refrigerator according to the seventh aspect of the present invention, wherein fins are arranged on the end surface of the cylindrical portion of the heat stage exposed in the expansion chamber.

[0037]

In the regenerative refrigerator according to the first aspect of the invention, at least one of the inner peripheral surface of the cylinder and the outer peripheral surface of the displacer is coated with a low-friction material. When the displacer is mounted and used, the outer surface of the displacer reciprocates while abutting on the inner surface of the cylinder via a low-friction material, and the amount of heat generated by the reciprocation is reduced. Furthermore, low
Since the friction material has an annular groove in the circumferential direction, the seal part
Of the displacer from the hot side expansion chamber due to
Helium gas flowing through the circumference to the cold side expansion chamber
Flow velocity is slower in the annular groove and faster outside the annular groove
And as a result, the pressure loss is large and the so-called labyrinth
The effect reduces the amount of leaked gas. Also, the display
Impurity gas contained in the helium gas on the outer periphery of the
This will accumulate in the shape of the groove and freeze.
To prevent the displacer from reciprocating
You.

Further, in the regenerative refrigerator according to the second aspect of the invention , the annular groove in the circumferential direction is formed on one side of the outer peripheral surface of the scotch yoke shaft of the driving means and the inner peripheral surface of the receiving portion of the scotch yoke shaft. And a ring-shaped seal body having a minute gap with the other side of the outer peripheral surface of the Scotch yoke shaft and the inner peripheral surface of the receiving portion is loosely fitted in the annular groove to form the seal portion of the Scotch yoke shaft. The ring-shaped seal body has one end
The side is idle and no mechanical stress is applied,
The outer surface of the Scotch yoke shaft
Friction between the inner peripheral surface of the receiving portion and the other side is suppressed. Also,
The seal moves back and forth with the reciprocation of the Koch yoke shaft.
Moving, the side surface of the seal body and the inner wall surface of the annular groove come into contact,
The contact area between the side surface of this seal and the inner wall surface of the annular groove and
And the other side of the inner peripheral surface of the receiving part and the outer peripheral surface of the Scotch yoke shaft.
Airtightness is ensured by the minute gap with the seal body .

Further, in the regenerative refrigerator according to the third aspect of the present invention , since the plurality of displacers are connected in the axial direction of the displacer by the joints made of permanent magnets, the axis of the cylinder and the displacer can be easily aligned. Therefore, there is no need to take a complicated joint structure, and the manufacturing accuracy of the cylinder assembly can be reduced.

Further, in the regenerative refrigerator according to the fourth aspect of the present invention , since the adsorbent is disposed between the gas inlet end of the displacer and the regenerator, the gas fed from the gas inlet end of the displacer is provided. The water vapor and oil vapor contained therein are taken into the adsorbent, and the accumulation of water vapor and oil vapor in the regenerator is suppressed.

In the regenerative refrigerator according to the fifth aspect of the present invention , at least one of the regenerators built in one of the plurality of displacers has a partition plate arranged at an angle to the axis of the regenerator. Since each partition space formed by the partition plate is filled with a different type of cold storage material, a plurality of different cold storage materials are present in a plane orthogonal to the axial direction of the regenerator. The regenerator material has specific heat peaks at different temperatures in the predetermined temperature region, and the specific heat in the predetermined temperature region is averaged.

Also, in the regenerative refrigerator according to the sixth aspect of the present invention , since a drawing tube is used for the cylinder,
A thin precision cylinder can be easily manufactured without the need for cutting, and the processing cost is reduced.

In the regenerative refrigerator according to the seventh aspect of the present invention , a drawing tube is used for each of the plurality of cylinders, and the heat stage is formed of a cylindrical portion and a truncated hollow conical portion. The cylinder is inserted and joined in the cylinder, the other cylinder is inserted and joined in the truncated cone, and the multiple stages of cylinders are air-tightly connected by the heat stage. When there is no protrusion, for example, when inserted and mounted in a refrigerator mounting cylinder, the gap between the refrigerator mounting cylinder and the cylinder of the regenerative refrigerator can be reduced, and the generation of heat convection of helium gas filling the gap is suppressed. Can be

In the regenerative refrigerator according to the eighth aspect of the present invention , since the fins are provided on the end surface of the cylindrical portion of the heat stage exposed in the expansion chamber, the heat transfer area of the heat stage increases. The heat is efficiently transferred from the cooled helium gas in the expansion chamber to the heat stage.

[0045]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. Reference Example 1. Figure 1 is a fragmentary cross-sectional view of regenerative refrigerator showing a reference example 1 of the present invention, with the same reference numerals, the same or corresponding portions of the conventional regenerative refrigerator shown in FIGS. 23 and 24 in FIG. And the description is omitted.

In Reference Example 1, the second stage displacer 2b (displacer 2) is made of stainless steel, which is a low thermal conductive material, and the outer peripheral surface of the second stage displacer 2b is coated with a polyimide resin, which is a low friction material. Thus, a low friction material coating layer 50 is formed. Also, the second
The regenerator 5b includes a wire mesh 5 in the second displacer 2b.
1 is inserted, then a filter 52 is inserted, and then a lead ball as a cold storage material is filled. Further, a filter 52 and a wire net 51 are inserted.
Is fixed. Here, the wire netting 51 and the filter 52 allow the helium gas 15 to pass therethrough and prevent the passage of lead balls and lead ball powder. Further, heat stages (first and second heat stages 9 and 1 in the figure)
0) is to provide a groove 54 for the pool in the inner wall surface,
The outer surface of the displacer 2 is brazed.

In the regenerative refrigerator according to the first embodiment having the above-described structure, when the refrigerator is horizontally mounted on a superconducting magnet or the like, the outer peripheral surface of the displacer 2 has a cylinder 1 (in FIG. Second stage cylinder 1
It reciprocates while contacting the inner peripheral surface of b), and the amount of heat generated by friction is reduced.

According to the first embodiment , the displacer 2
The low-friction material coating layer 50 is formed on the outer peripheral surface of the cylinder, so that the amount of heat generated by friction between the displacer 2 and the cylinder 1 can be reduced, seizure due to heat generation can be prevented, the maintenance period can be lengthened, and stable. Cooling performance can be obtained.

Since the displacer 2 is made of stainless steel, the heat conductivity of the displacer 2 is low.
Heat generated by friction between the displacer 2 and the cylinder 1 is hardly transmitted to the regenerator 5, and more stable cooling performance can be obtained.

Further, since the row 54 is provided on the inner wall surface of the heat stage, when the brazing is performed on the outer peripheral surface of the cylinder 1, the periphery of the row is improved, and the bonding strength can be increased.

Reference Example 2 In the first embodiment , the low-friction material coating layer 50 is formed on the outer peripheral surface of the displacer 2. In the second embodiment , as shown in FIG. Forming a layer 50;
A similar effect is achieved.

In the first and second embodiments , the low-friction material coating layer 50 is formed of a polyimide resin. However, the low-friction material coating layer 50 may be a low-friction material, for example, using Teflon. be able to.

Embodiment 1 Embodiment 1 is an embodiment according to the first invention . FIG. 3 is a sectional view of a main part of the regenerative refrigerator according to the first embodiment of the present invention. In the first embodiment , the low friction material coating layer 50 is formed on the outer peripheral surface of the second stage displacer 5 b (the displacer 2), and the annular groove 55 is formed on the low friction material coating layer 50 in the circumferential direction of the displacer 2. A plurality is formed along two axial directions.

Next, the operation of the first embodiment will be described. When the airtightness of the second-stage seal 7 decreases, for example, the first-stage expansion chamber 12
Helium gas 15 flows into the second-stage expansion chamber 13 through the gap between the displacer 2 and the cylinder 1 via the second-stage seal 7. When the helium gas 15 flows along the outer peripheral surface of the displacer 2 along the axial direction, the helium gas 15 is expanded in the groove 55 to reduce the flow velocity, and is reduced between the grooves 55 to increase the flow velocity, and the expansion and contraction is repeated. As a result, the pressure loss increases and the labyrinth effect stops the flow.

Here, the first and second regenerators 5a and 5b are constituted by using, for example, a copper wire mesh and a lead ball as regenerative materials, respectively, and the ultimate temperature of the first and second heat stages 9 and 10 is set to 60K. And 15K, the second-stage displacer 2b moves from about 60K to about 15K along the axial direction.
Temperature gradient. On the other hand, the helium gas _{15, H 2 O, CH 4,} N 2, O 2, H includes a gas such as _2, these _{H 2 O, CH 4, N} 2, O 2, H 2 , etc. Have different freezing temperatures. Also, the second
Helium gas 15 is filled in the gap between the stage displacer 2b and the second stage cylinder 1b. Therefore, the gas is frozen in the circumferential direction on the outer peripheral surface of the second-stage displacer 5b where the freezing temperature of the gas matches the wall surface temperature, and the frozen gas hinders the sliding of the displacer 2. However, the gas accumulates and freezes in a plurality of annular grooves 55 formed along the axial direction on the outer peripheral surface of the second-stage displacer 5b, so that hindrance to sliding of the displacer 2 is prevented.

As described above, according to the first embodiment , since a plurality of annular grooves 55 are provided on the outer peripheral surface of the displacer 2 along the axial direction, even if the airtightness of the second-stage seal 7 is reduced, The flow of the helium gas 15 from the first-stage expansion chamber 12 to the second-stage expansion chamber 13 can be prevented by the labyrinth sealing effect.

Further, other gases contained in the helium gas 15 accumulate in the annular groove 55 and freeze, so that it is possible to prevent the dislocation of the displacer 2 from being hindered by the freezing of those gases, and to prevent damage and the like. The maintenance period can be extended.

Embodiment 2 FIG. The second embodiment is another embodiment according to the first invention . In Embodiment 1, to form a low friction material coating layer 50 on the outer peripheral surface of the displacer 2, although it is assumed that a plurality in the low friction material coating layer 50 along the annular groove 55 in the axial direction formed, this embodiment In No. 2 , the low friction material coating layer 50 is formed on the inner peripheral surface of the cylinder 1, and a plurality of annular grooves 55 are formed in the low friction material coating layer 50 along the axial direction.

Embodiment 3 FIG. The third embodiment is another embodiment according to the first invention . In Embodiment 1, to form a low friction material coating layer 50 on the outer peripheral surface of the displacer 2, although it is assumed that a plurality in the low friction material coating layer 50 along the annular groove 55 in the axial direction formed, this embodiment In No. 3 , the low friction material coating layer 50 is formed on the inner peripheral surface of the cylinder 1, and grooves are formed in the low friction material coating layer 50 in a spiral shape along the axial direction, and the same effect is obtained.

Reference Example 3 FIG. 4 is a sectional view of a main part of a regenerative refrigerator according to a third embodiment of the present invention. In the third embodiment , a ring-shaped guide bearing 56 made of a low-friction material, for example, a polyimide resin or a Teflon resin is fixed to two locations on the outer peripheral surface of the second-stage displacer 2b (displacer 2).

According to the reference example 3 , the displacer 2
When sliding, the outer peripheral surface of the guide bearing 56 slides while rubbing against the inner peripheral surface of the cylinder 1. As a result, there is no rubbing between the outer peripheral surface of the displacer 2 and the inner peripheral surface of the cylinder 1, heat generation due to friction between the guide bearing 56 and the cylinder 1 can be suppressed, and the sliding of the displacer 2 can be made smooth. Cooling performance can be obtained.

Reference Example 4 In Reference Example 3, but it is assumed to provide a guide bearing 56 on the outer peripheral surface of the displacer 2, the reference example
In No. 4 , the guide bearing 56 is provided on the inner peripheral surface of the cylinder 1, and the same effect is obtained.

Reference Example 5 FIG. 5 is a sectional view showing a main part of a regenerative refrigerator according to a fifth embodiment of the present invention . In FIG.
an annular groove formed in the circumferential direction on the high temperature side of b (displacer 2); 58, a stainless steel ring; 59, a low friction material coating layer formed by coating the outer peripheral surface of the ring 58 with, for example, a polyimide resin; 60 is a ring body 5
8 and a low friction material coating layer 59. The seal body 60 can secure a clearance of about 1 μm with respect to the inner peripheral surface of the second cylinder 1b (cylinder 1). So that its outer diameter is made
It is loosely fitted in the annular groove 57.

Next, the operation of the fifth embodiment will be described. Seal body 60 loosely fitted in annular groove 57
Reciprocates with an inner peripheral surface of the second stage cylinder 1b with a clearance of about 1 μm to prevent leakage of the helium gas 15 between the inner peripheral surface of the second stage cylinder 1b. Further, the seal body 60 moves in the axial direction in the annular groove 57 due to the differential pressure on both sides, abuts against the inner wall side surface of the annular groove 57,
The leakage of the helium gas 15 through the annular groove 57 is prevented. Furthermore, even when the regenerative refrigerator is mounted horizontally, for example, even if the second stage displacer 2b is misaligned,
The seal body 60 has a bottom wall surface of the annular groove 57 and the second stage cylinder 1 formed by a loose fitting structure of the seal body 60 and the annular groove 57.
There is no compression between the inner peripheral wall of b.

As described above, according to the reference example 5 , the second
A ring-shaped seal body 60 having a clearance of about 1 μm between the inner peripheral surface of the stage cylinder 1b and the ring-shaped seal body 60 is loosely fitted into an annular groove 57 formed in the circumferential direction on the outer peripheral surface of the second stage displacer 2b. Therefore, a seal portion for preventing leakage of the helium gas 15 can be formed, and no mechanical stress acts on the seal body 60, so that abrasion due to reciprocal movement of the second-stage displacer 2b is suppressed, and a high-performance, long A long-lasting seal is obtained.

The ring member 58 of the seal member 60 is
Since it is made of the same stainless steel as the stage cylinder 1b,
Even at extremely low temperatures, the clearance between the seal body 60 and the second cylinder 1b can be secured, and an excellent sealing effect can be obtained.

In the fifth embodiment , the clearance between the seal body 60 and the second cylinder 1b is set to 1 μm. If the clearance is 3 μm or less, a sealing effect is obtained.

Reference Example 6 In the above-described reference example 5 , the low friction material coating layer 59 is formed on the stainless steel ring body 58 to form the seal body 60. In the reference example 6 , as illustrated in FIG. Is formed of a Teflon ring body which is a low friction material, and the same effect is obtained.

Reference Example 7 In the reference example 5 , the annular groove 57 is formed on the outer peripheral surface of the second-stage displacer 2b, and the seal body 60 is loosely fitted into the annular groove 57 with a clearance of about 1 μm with the inner peripheral surface of the second-stage cylinder 1b. This Reference Example 7
7, an annular groove 57 is formed in the inner peripheral surface of the second-stage cylinder 1b, and the seal body 60 has a clearance of about 1 μm with the outer peripheral surface of the second-stage displacer 2b.
Are loosely fitted in the annular groove 57, and the same effect is obtained.

Embodiment 4 FIG. Embodiment 4 is an embodiment according to the second invention . FIG. 8 is a sectional view of a main part of a regenerative refrigerator according to a fourth embodiment of the present invention. In the drawing, reference numeral 61 denotes a drive mechanism 20, and a scotch yoke shaft 61 for reciprocating the displacer 2; It is a receiving part of.

In the fourth embodiment, an annular groove 57 is formed in the inner circumferential surface of the receiving portion 62 in the circumferential direction, and the ring-shaped seal body 60 is formed with a clearance of 1 μm between the inner circumferential surface of the receiving portion 62 and the outer circumferential surface of the scotch yoke shaft 61. Shall be loosely fitted in the annular groove 57,
The same effects as those of the ninth embodiment can be obtained.

Embodiment 5 FIG. Embodiment 5 is another embodiment according to the second invention . In the fourth embodiment , the annular groove 57 is formed in the inner peripheral surface of the receiving portion 62 in the circumferential direction, and the ring-shaped seal body 60 is formed with a clearance of 1 μm between the annular groove 57 and the outer peripheral surface of the Scotch yoke shaft 61. Although it is assumed that it fits loosely in 57,
In the fifth embodiment , as shown in FIG. 9, an annular groove 57 is formed in the outer peripheral surface of the scotch yoke shaft 61 in the circumferential direction, and a ring-shaped groove having a clearance of 1 μm is formed between the groove 57 and the inner peripheral surface of the receiving portion 62. The seal body 60 is loosely fitted in the annular groove 57, and the same effect is obtained.

Reference Example 8 FIG. 10 is a sectional view of a main part of a regenerative refrigerator according to Embodiment 8 of the present invention . In the drawing , reference numeral 63 denotes a fitting having a T-shaped cross section, and the fitting 63 is a second-stage displacer 2b.
Is screwed to the end. Reference numeral 64 denotes a ring-shaped fixing plate fixed to the end of the first-stage displacer 2a by a fixing bolt 65, and 66 denotes a concave portion formed at the end of the first-stage displacer 2a. The joint portion is constituted by the concave portion 66.

In the reference example 8 , one end of the joint fitting 63 screwed to the end of the second stage displacer 2b is connected to the recess 66.
Then, the fixing plate 64 is fixed to the end of the first-stage displacer 2a by fixing bolts 65 to connect the first-stage and second-stage displacers 2a and 2b.
Here, the depth of the concave portion 66 is formed larger than the thickness of the joint fitting 63, and the first and second stage displacers 2a, 2b are connected so as to have an axial play.

As described above, according to the reference example 8 , the first
Since the stage and the second stage displacers 2a and 2b are connected in the axial direction with an axial play, the cylinder 1 is cooled faster than the displacer 2 in the initial cooling process. The heat shrinkage of 1 is absorbed by the play in the axial direction of the joint portion, so that the collision between the cylinder 1 and the displacer 2 is prevented, and the equipment is not damaged.

Reference Example 9 FIG. 11 is a sectional view of a main part of a regenerative refrigerator according to a ninth embodiment of the present invention . In the drawing , reference numeral 67 denotes a spring as an elastic member.

In the ninth embodiment , one end of the joint fitting 63 screwed to the end of the second stage displacer 2 b is connected to a spring 67.
, And the fixing plate 64 is fixed to the end of the first-stage displacer 2a with fixing bolts 65, so that the first-stage and second-stage displacers 2a,
2b are connected. Here, the first-stage and second-stage displacers 2a and 2b are connected with the spring 67 contracted between the bottom surface of the concave portion 66 and the joint fitting 63.

As described above, according to the ninth embodiment , the first
Since the stage and the second stage displacers 2a and 2b are connected in the axial direction with the spring 67 contracted, the cylinder 1 is cooled faster than the displacer 2 in the initial cooling process, and even if the cylinder 1 is thermally contracted more greatly. , This cylinder 1
Is absorbed by the elasticity of the spring 67 of the joint,
Collision between the cylinder 1 and the displacer 2 is prevented, so that damage to the equipment does not occur. Also, the first stage and the second stage
Since the step displacers 2a and 2b are connected without any play in the axial direction, the reciprocating movement of the displacer 2 becomes smooth.

Embodiment 6 FIG. The sixth embodiment is an embodiment according to the third invention . FIG. 12 is a cross-sectional view of a main part of a regenerative refrigerator according to a sixth embodiment of the present invention. In FIG. 12, reference numeral 68 denotes a first permanent magnet having a spherical tip and fixed to an end of a second stage displacer 2b; Reference numeral 69 denotes a plate-shaped second permanent magnet fixed to the end of the first stage displacer 2a.
The permanent magnets 68 and 69 form a joint.

In the sixth embodiment , the first and second stage displacers 2a and 2b are connected by the attraction of the first and second permanent magnets 68 and 69, and the tip of the first permanent magnet 68 is spherical. Therefore, the first and second permanent magnets 68 and 69 are substantially in point contact, and the second stage displacer 2b is swingably connected to the first stage displacer 2a about the contact point. I have.

As described above, according to the sixth embodiment , the axes of the cylinder 1 and the displacer 2 can be easily aligned, and it is not necessary to increase the accuracy of the cylinder assembly, and the cost can be reduced.

Reference Example 10 FIG. 13 is a cross-sectional view of a cold storage material used for a cold storage refrigerator showing a tenth embodiment of the present invention.

In Reference Example 10 , a cold storage material 72 is formed by coating the surface of a particle 70 made of Er ₃ Ni which is an alloy of a rare earth metal with a coating layer 71 of In which is a superconducting material. The third stage regenerator 5c is formed by filling the inside of the third stage displacer 2c.

Here, when the specific heat of the cold storage material 72 with respect to the temperature was measured, as shown in FIG. 14, in addition to the specific heat peak of Er ₃ Ni at the temperature T ₁ (about 7.6 K),
The specific heat peak of In at the temperature T ₂ (about 5 K: corresponding to the superconducting transition point of In) was obtained.

As described above, according to Reference Example 10 , Er ₃
Since the cold storage material 71 is formed by coating the surface of the Ni particles 70 with the coating layer 71 of In, which is a superconducting material, the cold storage material is larger on the low temperature side than when the cold storage material is composed of Er ₃ Ni alone. Specific heat can be obtained, and the cold storage efficiency on the low temperature side can be improved.

In the above-described reference example 10 , the regenerator material 72 is formed by coating the surface of the granular material 70 made of Er ₃ Ni with the coating layer 71 of In. However, as shown in FIG. Even if the cold storage material 72 is formed by integrating Er ₃ Ni and In, the cold storage material 72 is formed by melting and integrating Er ₃ Ni and In as shown in FIG.
To achieve the same effect.

Further, in Reference Example 10 , Er ₃ Ni and In are integrated to form the regenerator material 72, but the combination of the rare earth metal alloy (compound) and the superconducting material is not limited to this. Is not something, for example, Ho
_1.5 Er _1.5 Ru and Pb, and Ho _1.5 Er _1.5 Ru and Nb are used. Furthermore, a superconducting material such as In, Nb, Pb, Ta or the like can be used alone as a cold storage material by using a preparing machine whose specific heat is increased by superconducting transition.

Embodiment 7 FIG. Embodiment 7 is an embodiment according to the fourth invention . FIG. 16 is a cross-sectional view of a main part of a regenerative refrigerator according to a seventh embodiment of the present invention. In the drawing, reference numeral 73 is provided between the gas inflow end of the second-stage displacer 2b and the second-stage regenerator 5b. The adsorbent 73 is made of, for example, molecular sieves, silica gel, or activated carbon.

The helium gas 15 contains water vapor and oil vapor. These water vapor and oil vapor accumulate in the regenerator 5 to lower the regenerative efficiency and become fine solids to form a seal portion. Causes deterioration.

As described above, according to the seventh embodiment , since the adsorbent 73 is provided between the gas inflow end of the second-stage displacer 2b and the second-stage regenerator 5b, the helium gas 1
The water vapor and oil vapor contained in the fuel gas 5 are adsorbed by the adsorbent 73 to prevent the gas from entering the regenerator 5, whereby a decrease in the efficiency of the cold storage and a deterioration of the seal portion can be suppressed.

Embodiment 8 FIG. Embodiment 8 is an embodiment according to the fifth invention . FIG. 17 is a sectional view of a main part of a regenerative refrigerator according to an eighth embodiment of the present invention. In the figure, reference numeral 75 denotes a flat partition plate made of, for example, felt. The second-stage regenerator 5b has a plurality of partitioning plates 75 disposed at an angle with respect to the axis thereof, and each partitioning space formed by these partitioning plates 75 is filled with different cold storage materials 76a to 76d. ,
It is configured such that different cold storage materials are mixed in a cross section perpendicular to the axis.

Next, the operation of the eighth embodiment will be described. In the reciprocating movement of the second stage displacer 2b in one cycle, the second stage regenerator 5b has a case where the high-pressure and high-temperature helium gas 15 flows from the high-temperature side and a case where the low-pressure and low-temperature helium gas 15 flows from the low-temperature side. . When the high-pressure and high-temperature helium gas 15 flows from the high-temperature side, the temperature of the section A in the drawing is Ta, and the low-pressure and low-temperature helium gas 15
When the temperature of the cross section A in the figure when
In this case, the temperature of the cross section A changes in the range between Ta and Tb in one cycle.

Here, if the cross section A is constituted only by the cold storage material 76a, the cold storage efficiency becomes optimum when the high-pressure and high-temperature helium gas 15 flows, but the low-pressure and low-temperature helium gas 1
When 5 flows in, the cold storage efficiency will be significantly reduced. On the other hand, if the cross section A is composed only of the cold storage material 76b, the cold storage efficiency becomes optimal when the low-pressure and low-temperature helium gas 15 flows in, but the cold storage efficiency drops significantly when the high-pressure and high-temperature helium gas 15 flows. become.

In the eighth embodiment , the cross section A is the cold storage material 76.
a and the cold storage material 76b are mixed.
Therefore, by selecting a material that can obtain a specific heat peak at the temperature Ta as the cold storage material 76a and selecting a material that can obtain a specific heat peak at the temperature Tb as the cold storage material 76b, A
The specific heat of the cross section is apparently averaged, and there is no place where the temperature becomes extremely bad even if the temperature swings from Ta to Tb. Therefore, even if the temperature swings in one cycle, the cold storage efficiency can be improved. In Example 8 , GdRh (Ta: 19.2K), Gd _0.8 Er _0.2 was used as the cold storage materials 76a to 76d.
Rh (Tb: 12.6K), Gd _0.5 Er _0.5 Rh (T
c: 4.7 K) and ErRh (Td: 3.2 K) were selected, and apparently averaged specific heat was obtained as shown by the dotted line in FIG. Was.

As described above, according to the eighth embodiment , the plurality of partition plates 75 are formed at an angle with respect to the axis of the second stage regenerator 5b.
Are arranged and filled with different cold storage materials 76a to 76d in the respective partition spaces formed by the partition plates 75, so that different cold storage materials are mixed in a cross section perpendicular to the axis, and The specific heat of the cold storage material is apparently averaged from the high-temperature side to the low-temperature side of the regenerator 5b, so that the cooling efficiency can be improved with respect to the temperature amplitude in one cycle, and the cooling performance can be improved.

Embodiment 9 FIG. The ninth embodiment is another embodiment according to the fifth invention . In the eighth embodiment , a plurality of flat partition plates 75 are disposed at an angle with respect to the axis of the second stage regenerator 5b, and different cold storage materials 76a to 76d are provided for each partition space formed by the partition plates 75. it is assumed to be filled, but the real
In the ninth embodiment, as shown in FIG. 19, a partition plate 75 formed in a conical shape is disposed symmetrically with respect to the axis of the second-stage regenerator 5b, and is formed by the partition plate 75. Different cooling storage materials 76e and 76f are filled for each partition space, and the same effect is exerted.

Embodiment 10 FIG. The tenth embodiment is an embodiment according to the sixth to eighth inventions . FIG. 20 is a sectional view of a cylinder used in a regenerative refrigerator according to a tenth embodiment of the present invention. In the drawing, reference numerals 77a, 77b, and 77c denote first and second stages, each of which is a thin stainless steel drawn tube. Tier and third
As shown in FIG. 21, the stepped cylinders 78 and 79 have a cylindrical portion 78a (79a) and a truncated hollow conical portion 78b (79b).
A first and second stage copper heat stage consisting of a first stage, a second stage and a third stage cylinder, and a first stage, a second stage and a third stage made of copper. 1st, 2nd and 3rd heat stages 7
8, 79 and 81 constitute a cylinder 77.

In order to assemble the cylinder 77 constructed as described above, first, the cylindrical portion 78a of the first-stage heat stage 78 is inserted into the first-stage cylinder 77a and brazed, and the first-stage cylinder 77a and the One-stage heat stage 78
And join. Next, the second-stage cylinder 77b is inserted into the truncated hollow conical portion 78b of the first-stage heat stage 78 and brazed to join the first-stage heat stage 78 and the second-stage cylinder 77b. Similarly, the second-stage cylinder 77
b and the second stage heat stage 79, and
The stage heat stage 79 and the third stage cylinder 77c are joined. Finally, the third-stage heat stage 81 is inserted and brazed into the third-stage cylinder 77c,
The three-stage cylinder 77 is assembled by joining the third stage 7c and the third stage heat stage 81.

The cylinder 7 thus assembled
7 are the first stage, the second stage and the third stage as shown in FIG.
First from the outer peripheral surface of the step cylinder 77a, 77b, 77c.
Stage, second stage and third stage heat stages 78, 79, 8
1 is configured not to protrude. Also, the first stage,
Fins 80 are formed on the end surfaces of the second and third heat stages 78, 79, 81 that are exposed inside the cylinder, thereby increasing the heat transfer area.

According to the tenth embodiment , a thin stainless steel drawing tube is used for the first, second and third-stage cylinders 77a, 77b and 77c, so that the processing cost of the cylinders is reduced and the cold storage The price of the type refrigerator can be reduced.

The cylindrical portion 78a and the truncated hollow conical portion 78
b, the connection between the cylinders is established, so that the heat stage does not protrude from the outer peripheral surface of the cylinder. For example, as shown in FIG.
When the regenerative refrigerator is mounted in the refrigerator mounting cylinder 36, the inner wall surface of the refrigerator mounting cylinder 36 and the cylinder 77
Of the helium gas in the space can be suppressed, and the cooling efficiency can be improved.

Further, since the fins 80 are formed on the end faces exposed in the cylinder of the heat stage, the contact area between the helium gas 15 passing through the expansion chamber and the heat stage increases, and the heat transfer area increases. The heat of the helium gas 15 is efficiently transmitted to the heat stage.

Embodiment 11 FIG. The eleventh embodiment is another embodiment according to the eighth invention . In the tenth embodiment , the fin 80 including the annular protrusion is provided on the end surface of the heat stage.
In the eleventh embodiment , as shown in FIG. 22, a plurality of fins 80 composed of columnar projections are provided on the end surface of the heat stage, and the same effect is obtained.

[0104]

Since the present invention is configured as described above, it has the following effects.

In the regenerative refrigerator according to the first aspect of the present invention, at least one of the inner peripheral surface of the cylinder and the outer peripheral surface of the displacer is coated with a low-friction material.
Since the annular groove is provided in the circumferential direction, the calorific value due to the rubbing of the cylinder and the displacer is reduced, the cold storage efficiency can be improved, and the cooling performance can be improved .
Gas passing through the outer periphery of the displacer due to leakage of the seal
The labyrinth effect to prevent the flow of
I can do it. In addition, impure gas contained in the gas is transferred into the groove.
Wrap and slide the displacer due to frozen impurity gas
Can be inhibited .

Further, in the regenerative refrigerator according to the second aspect of the present invention , an annular groove in the circumferential direction is formed on one side of the outer peripheral surface of the scotch yoke shaft of the driving means and the inner peripheral surface of the receiving portion of the scotch yoke shaft. The seal portion of the Scotch yoke shaft is formed by loosely fitting a ring-shaped seal body having a small gap with the other side of the outer peripheral surface of the Scotch yoke shaft and the inner peripheral surface of the receiving portion into the annular groove. And no wear due to mechanical stress.
Periodically stable confidentiality can be secured .

Further, in the regenerative refrigerator according to the third aspect of the present invention , since the plurality of displacers are connected in the axial direction of the displacer by the joints made of permanent magnets, the axis of the cylinder and the displacer can be easily aligned. In addition, the manufacturing accuracy of the cylinder assembly can be reduced.

Further, in the regenerative refrigerator according to the fourth aspect of the present invention , since the adsorbent is disposed between the gas inlet end of the displacer and the regenerator, steam or oil vapor contained in the gas, Alternatively, those solidified substances are removed, and a decrease in the cool storage efficiency is suppressed, and the deterioration of the seal portion is also suppressed.

Further, in the regenerative refrigerator according to the fifth aspect of the invention , at least a regenerator built in one of the plurality of displacers is provided with a partition plate at an angle with respect to the axis of the regenerator. Since different types of cold storage materials are filled in each partition space formed by the partition plate, a plurality of different cold storage materials are mixed in a plane orthogonal to the axial direction of the regenerator, and the specific heat Averaging is achieved, and the efficiency of the regenerative refrigerator can be improved even when the temperature swings.

Further, in the regenerative refrigerator according to the sixth aspect of the present invention , since the drawing tube is used for the cylinder, the processing cost of the cylinder is reduced, and the price of the device is reduced.

In the regenerative refrigerator according to the seventh aspect of the present invention , a drawing tube is used for each of a plurality of cylinders, and a heat stage is formed from a cylindrical portion and a truncated hollow conical portion. Insert and join the cylindrical part inside
Since the other cylinder is inserted and joined in the truncated cone and the multiple stages of cylinders are air-tightly connected by the heat stage, the heat stage does not project from the outer peripheral surface of the cylinder. The gap between the helium gas and the refrigerator mounting cylinder is reduced, the convection of helium gas filling the gap is suppressed, and the cooling performance can be improved.

Further, in the regenerative refrigerator according to the eighth aspect of the present invention , since the fins are provided on the end surface of the cylindrical portion of the heat stage exposed in the expansion chamber, the heat transfer area is enlarged and the inside of the expansion chamber is reduced. The heat of the gas is efficiently transmitted to the heat stage.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a regenerative refrigerator according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a regenerative refrigerator according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a main part of the regenerative refrigerator according to the first embodiment of the present invention.

FIG. 4 is a sectional view of a main part of a regenerative refrigerator according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a main part of a regenerative refrigerator according to a fifth embodiment of the present invention.

FIG. 6 is a perspective view of a seal used in a regenerative refrigerator according to a sixth embodiment of the present invention.

FIG. 7 is a sectional view of a main part of a regenerative refrigerator according to a seventh embodiment of the present invention.

FIG. 8 is a sectional view of a main part of a regenerative refrigerator according to a fourth embodiment of the present invention.

FIG. 9 is a sectional view of a main part of a regenerative refrigerator according to a fifth embodiment of the present invention.

FIG. 10 is a sectional view of a main part of a regenerative refrigerator according to a eighth embodiment of the present invention.

FIG. 11 is a cross-sectional view of a main part of a regenerative refrigerator according to a ninth embodiment of the present invention.

FIG. 12 is a sectional view of a main part of a regenerative refrigerator according to a sixth embodiment of the present invention.

FIG. 13 is a cross-sectional view of a cold storage material used in a cold storage refrigerator showing a tenth embodiment of the present invention.

FIG. 14 is a graph showing the relationship between the temperature of the cold storage material used in the cold storage refrigerator according to Embodiment 10 of the present invention and the specific heat.

FIGS. 15A and 15B are reference diagrams of the present invention, respectively.
It is sectional drawing corresponding to implementation of the cold storage material used for the cold storage refrigerator shown in Example 10 .

FIG. 16 is a sectional view of a main part of a regenerative refrigerator according to a seventh embodiment of the present invention.

FIG. 17 is a sectional view of a main part of a regenerative refrigerator according to an eighth embodiment of the present invention.

FIG. 18 is a graph showing the relationship between the temperature of the cold storage material used in the cold storage refrigerator according to the eighth embodiment of the present invention and the specific heat.

FIG. 19 is a sectional view of a main part of a regenerative refrigerator according to a ninth embodiment of the present invention.

FIG. 20 is a sectional view of a cylinder used in a regenerative refrigerator according to a tenth embodiment of the present invention.

FIG. 21 is a perspective view of a heat stage used in a regenerative refrigerator according to a tenth embodiment of the present invention.

FIG. 22 is a perspective view of a heat stage used in a regenerative refrigerator according to an eleventh embodiment of the present invention.

FIG. 23 is a sectional view showing an example of a conventional regenerative refrigerator.

FIG. 24 is a sectional view of a main part of a conventional regenerative refrigerator.

FIG. 25 is a cross-sectional view showing a seal structure in a conventional regenerative refrigerator.

FIGS. 26A and 26B are a cross-sectional view and a perspective view, respectively, showing a seal structure in a conventional regenerative refrigerator.

FIG. 27 is a cutaway perspective view showing a superconducting magnet equipped with a conventional regenerative refrigerator.

FIG. 28 is a cross-sectional view showing a mounting structure of a regenerative refrigerator in a conventional superconducting magnet.

[Explanation of symbols]

1 cylinder, 1a first stage cylinder, 1b second stage cylinder, 1c third stage cylinder, 2 displacer,
2a first stage displacer, 2b second stage displacer, 2c third stage displacer, 5 regenerator, 5a
First stage regenerator, 5b Second stage regenerator, 5c Third stage regenerator, 6 First stage seal, 7 Second stage seal, 8 Third
Stage seal, 9 1st stage heat stage, 10 2nd stage heat stage, 11 3rd stage heat stage, 12 1st stage expansion room, 13 2nd stage expansion room, 50 Low friction material coating layer, 55 groove, 56 guide Bearing, 57
Annular groove, 60 seal body, 61 Scotch yoke shaft,
62 receiving part, 63 joint fitting (joint part), 64 fixing plate (joint part), 65 concave part (joint part), 67 spring (elastic member), 68 first permanent magnet (joint part), 69 second
Permanent magnet (joint part), 72 cold storage material, 73 adsorbent,
75 Partition plate, 76a-76f Cold storage material, 77a 1st
Stage cylinder, 77b second stage cylinder, 77c third stage cylinder, 78 first stage heat stage, 78a cylindrical portion, 78b truncated hollow cone portion, 79 second stage heat stage, 79a cylindrical portion, 79b truncated hollow cone portion , 80
Fins, 81 Third heat stage.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication F25B 9/00 F25B 9/00 H (72) Inventor Joji Ando 651 Tenwa, Ako-shi Mitsubishi Electric Inside Ako Mfg. Co., Ltd. (72) Inventor Mitsuhiro Kishida 8-1-1, Tsukaguchi Honcho, Amagasaki City Mitsubishi Electric Corporation Central Research Laboratory (72) Inventor Hideto Yoshimura 8-1-1, Tsukaguchi Honmachi, Amagasaki City Mitsubishi Electric Corporation (72) Inventor Masashi Nagao 8-1-1, Tsukaguchi Honcho, Amagasaki City Mitsubishi Electric Corporation Central Research Laboratory (72) Inventor, Takashi Inaguchi 8-1-1 Honcho Tsukaguchi, Amagasaki City Mitsubishi Electric Corporation (56) References JP-A-62-59344 (JP, A) JP-A-3-236549 (JP, A) JP-A-62-280553 (JP, A) JP 4-59884 (JP, A) JitsuHiraku Akira 62-147865 (JP, U) JitsuHiraku Akira 63-150260 (JP, U)

Claims (8)

(57) [Claims] 1. A cylinder having a heat stage mounted therein, a regenerator built-in, a displacer housed in the cylinder with a predetermined gap, and reciprocating in the cylinder, and a displacer disposed between the cylinder and the displacer. A seal portion provided, and a driving means for reciprocating the displacer in the cylinder, wherein the gas fed into the expansion chamber partitioned by the displacer is adiabatically expanded by the reciprocal movement of the displacer, and the heat stage A low-friction material is coated on at least one of an inner peripheral surface of the cylinder and an outer peripheral surface of the displacer , and an annular groove is provided in the low-friction material in a circumferential direction.
Regenerative refrigerator, characterized in that digit. 2. A cylinder having a heat stage mounted thereon, a displacer having a built-in regenerator and reciprocating in the cylinder, a seal disposed between the cylinder and the displacer, and a displacer. Driving means for reciprocating in the cylinder,
In the regenerative refrigerator that adiabatically expands the gas sent into the expansion chamber partitioned by the displacer and reciprocates the displacer, and cools the heat stage to a predetermined temperature, the outer peripheral surface of the scotch yoke shaft of the driving unit A circumferential annular groove is formed on one side of the inner peripheral surface of the receiving portion of the Scotch yoke shaft, and a minute gap is formed between the outer peripheral surface of the Scotch yoke shaft and the inner peripheral surface of the receiving portion. A regenerative refrigerator comprising a ring-shaped seal having a loose fit in the annular groove to form a seal portion for the Scotch yoke shaft. 3. A plurality of cylinders each having a heat stage mounted thereon, and a plurality of displacers each having a built-in regenerator and reciprocating in said cylinder.
A seal portion disposed between the cylinder and the displacer; and a driving unit for reciprocating the displacer in the cylinder.The gas fed into the expansion chamber partitioned by the displacer is supplied to the displacer by a gas. In a regenerative refrigerator that adiabatically expands by reciprocating movement and cools the heat stage to a predetermined temperature, the plurality of displacers are connected in the axial direction of the displacer by joints made of permanent magnets. Cool storage refrigerator. 4. A cylinder on which a heat stage is mounted, a displacer having a built-in regenerator and reciprocating in the cylinder, a seal disposed between the cylinder and the displacer, and a displacer. Driving means for reciprocating in the cylinder,
The gas fed into the expansion chamber partitioned by the displacer is adiabatically expanded by reciprocating movement of the displacer, and in a regenerative refrigerator that cools the heat stage to a predetermined temperature, a gas inflow end of the displacer, the regenerator, A regenerative refrigerator comprising an adsorbent disposed between the two. 5. A plurality of cylinders each having a heat stage mounted thereon, a plurality of displacers each having a built-in regenerator and connected in the axial direction of the cylinder and reciprocating in the cylinder. A seal portion disposed between the displacer and a driving unit for reciprocating the displacer in the cylinder, wherein a gas fed into an expansion chamber partitioned by the displacer is moved by the reciprocal movement of the displacer. In a regenerative refrigerator that adiabatically expands and cools the heat stage to a predetermined temperature, the regenerator built into at least one of the plurality of displacers includes:
A regenerative refrigerator having a partition plate disposed at an angle with respect to the axis of the regenerator and a different type of regenerator material filled in each partition space formed by the partition plate. 6. A cylinder on which a heat stage is mounted, a displacer having a built-in regenerator and reciprocating in the cylinder, a seal disposed between the cylinder and the displacer, and a displacer. Driving means for reciprocating in the cylinder,
In a regenerative refrigerator that adiabatically expands gas sent into an expansion chamber partitioned by the displacer by reciprocating the displacer and cools the heat stage to a predetermined temperature, a drawing tube is used for the cylinder. Regenerative refrigerator. 7. A plurality of cylinders each having a heat stage mounted thereon, a plurality of displacers each having a built-in regenerator and connected in the axial direction of the cylinder and reciprocating in the cylinder; A seal portion disposed between the displacer and a driving unit for reciprocating the displacer in the cylinder, wherein a gas fed into an expansion chamber partitioned by the displacer is moved by the reciprocal movement of the displacer. In the regenerative refrigerator that adiabatically expands and cools the heat stage to a predetermined temperature, a drawing tube is used for each of the plurality of cylinders, and the heat stage is formed from a cylindrical portion and a truncated hollow conical portion,
The cylinder portion is inserted and joined in one of the cylinders, and the other cylinder is inserted and joined in the truncated cone portion, and the plurality of cylinders are hermetically connected by the heat stage. Cool storage refrigerator. 8. A fin is provided on an end face of a cylindrical portion of a heat stage exposed in an expansion chamber.
8. The regenerative refrigerator according to 7 .