JPS6136145B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides independent 20K refrigeration circuits and 70K refrigeration circuits.
A swash plate driven cryogenic refrigerator having two circuits each, and two regenerators having a structure for pre-cooling the working gas of the 20K refrigeration circuit with the low temperature working gas of the 70K refrigeration circuit; By arranging the cylinders on the same circumference at angular intervals of 90°,
The object of the present invention is to provide an opposed cylinder type cryogenic refrigerator in which the range of torque fluctuations caused by changes in the pressure of working gas is smoothed to an extremely small extent, and the vibrations of the machine body caused by the torque fluctuations are extremely reduced.

An embodiment of the present invention will be described below based on the accompanying drawings.

Compression cylinders 1a and 1b and pistons 2a and 2
The compressed spaces 3a and 3b formed by the conduit 8
a, 8b, coolers 21a, 21b, regenerator 22,
23, and communicates with 20K expansion spaces 17b, 17a via conduits 9a, 9b, forming two separate 20K refrigeration circuits 100a, 100b. Said
The 20K expansion spaces 17a, 17b are formed by 20K expansion cylinders 16a, 16b and pistons 12a, 12b, and the pistons 12a, 12b are provided with piston seals 20a, 20a, 20b to prevent working gas from leaking from the 20K expansion spaces 17a, 17b. 20b is provided. Also, in order to prevent the working gas from leaking from the compression spaces 3a and 3b, the piston 2
Piston seals 5a, 5b are also provided in a, 2b, and the 20K expansion cylinders 16a, 1
Refrigeration load units 32a and 32b are installed on the portions surrounding the 20K expansion spaces 17a and 17b on the 6b.

Similarly, a compression space 13 formed by compression cylinders 11a, 11b and pistons 12a, 12b.
a, 13b are conduits 18a, 18b, cooler 31
a, 31b, regenerators 23, 22, and conduit 19
a, 19b, communicate with the 70K expansion spaces 7a, 7b, and two separate 70K refrigeration circuits 200a, 20
It constitutes 0b. Said 70K expansion space 7a, 7
b is formed from 70K expansion cylinders 6a, 6b and pistons 2a, 2b, and the piston 2
Piston seals 10a and 10a are installed in a and 2b to prevent working gas from leaking from the 70K expansion spaces 7a and 7b.
0b is provided, and the compression spaces 13a, 13
Piston seals 1 are also provided on the pistons 12a and 12b to prevent the working gas from leaking from the pistons 12a and 12b.
5a and 15b are provided.

The regenerators 22 and 23 each have one set of 20K.
Refrigeration circuit 100a or 100b and 70K refrigeration circuit 2
00b or 200a, and thermally couples both circuits 100a, 100b, 200a, and 200b. However, both circuits 100a, 100
b, 200a, 200b working gas or partition wall 2
They are separated by 4 and 25 and do not mix with each other.

Rods 4a, 4b, 14a, 14b are connected to the pistons 2a, 2b, 12a, 12b, and the rods 4a, 4b, 14a, 14b are connected to the swash plate via sliding bearings 41a, 41b, 51a, 51b. It's on top of 42. The swash plate 42 is
It is connected to a prime mover (not shown) via a shaft 43. Further, the drive device chamber 46 in which the swash plate 42 and the like are located is surrounded by a machine wall 45 and separated from the outside world, and a shaft sealing device 44 is provided at a portion where the shaft 43 penetrates the machine wall 45. It is being

Furthermore, the compression cylinder 1a, 70K expansion cylinder 6a, piston 2a, etc. are now combined to call the A cylinder, and the compression cylinder 1b, 70K, expansion cylinder 6b, piston 2b, etc. are combined to be called the B cylinder.
Furthermore, the compression cylinder 11a, the 20K expansion cylinder 16a, the piston 12a, the refrigeration load section 32a, etc. are combined into the C cylinder, and the compression cylinder 11
b, 20K expansion cylinder 16b, piston 12
If the refrigeration load section 32b and the like are collectively referred to as the D cylinder, the A cylinder and the B cylinder are at 180° opposing positions, and the C cylinder and D cylinder are also at 180° opposing positions.
Further, cylinders C and D are located at 90 degrees (perpendicular) to each other with respect to cylinder A, and cylinders C and D are also located at 90 degrees (perpendicular) to cylinder B. That is,
The four cylinders A, B, C, and D are arranged at angular intervals of 90 degrees and are further arranged on the same circumference.

In the above configuration, when the shaft 43 is rotated by a prime mover (not shown),
The swash plate 42 also rotates, and the sliding bearings 41a, 41
rods 4a, 4b, through b, 51a, 51b,
14a, 14b make reciprocating movements, and the rods 4a, 4
piston 2a connected to b, 14a, 14b,
2b, 12a, 12b also reciprocate. At this time, the working gas in the compression spaces 3a, 3b, 13a, 13b is compressed and the coolers 21a, 21b, 3
1a and 31b, and further cooled by regenerators 22 and 2.
3, 70K expansion spaces 7a, 7b, and
It expands upon reaching the 20K expansion spaces 17a and 17b, and provides refrigeration output at a low temperature.

The compression cylinders 1a, 1b, 11a and 11b and the pistons 2a, 2b, 12a and 12b each have a convex shape consisting of a large diameter part and a small diameter part, and each piston has a large diameter part of the corresponding cylinder. A compression space and an expansion space are respectively formed between the small diameter part and the small diameter part.

As described above, according to the present invention, when performing the above-mentioned action, the volume ratio (the ratio of the respective maximum volumes of the compression space and the expansion space) etc. can be appropriately selected. The working gas of the 20K refrigeration circuit can be precooled by the low-temperature working gas of the 70K refrigeration circuit through the regenerator that is thermally connected to the regenerator. In other words, by providing a pre-cooling type regenerator, it is possible to obtain an output at a lower temperature in the refrigeration load section than when a 20K refrigeration circuit exists alone.

In addition, by arranging the four cylinders A, B, C, and D on the same circumference at angular intervals of 90 degrees, the 20K
The range of torque fluctuations caused by pressure changes in the refrigeration circuit and the 70K refrigeration circuit can be smoothed to an extremely small extent, and the vibration of the aircraft caused by this torque fluctuation can be extremely reduced. For example, in Figure 4, if there is only one A cylinder (
The torque fluctuation T with respect to the rotation angle θ is shown for the curve) and the case where the four cylinders A, B, C, and D are arranged at angular intervals of 90° (curve). according to this,
As is clear from the curve, the torque fluctuation range can be made extremely small.

[Brief explanation of the drawing]

The figures all show one embodiment of the opposed cylinder type cryogenic refrigerator of the present invention, in which Fig. 1 is a partially cutaway plan view, Fig. 2 is a sectional view taken along line XX in Fig. 1, FIG. 3 is a cross-sectional view taken along the YY line in FIG. 1, and FIG. 4 is a graph showing the relationship of torque fluctuation to negative rotation θ. A, B, C, D: 4 cylinders, 22, 23: Regenerator, 100a, 100b: 20K refrigeration circuit, 20
0a, 200b: 70K refrigeration circuit.

Claims (1)

[Claims] 1. Four convex cylinders each having a large diameter portion and a small diameter portion, which are fitted into the corresponding convex cylinders to form a compression space and an expansion space, respectively, between the large diameter portion and the small diameter portion. four convex pistons, and four independent refrigeration circuits formed by connecting the compression space and the expansion space that are adjacent to each other via a cooler and a regenerator, and a large diameter portion of each cylinder. And by adjusting the size of the small diameter part as appropriate, two of the refrigeration circuits and the remaining two
In the swash plate driven cryogenic refrigerator, each of the four refrigeration circuits is a 20K refrigeration circuit and a 70K refrigeration circuit, and the working gas of the 20K refrigeration circuit is precooled in the regenerator of the 70K refrigeration circuit. A cryogenic refrigerator comprising two cylinders arranged on the same circumference at angular intervals of 90°, and two cylinders belonging to the same refrigeration circuit arranged at angular intervals of 180°.