JPS6251390B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Stirling cycle refrigerator, and more particularly to a Stirling cycle refrigerator with improved compression capacity.

A conventional Stirling cycle refrigerator has a compression cylinder with a built-in compression piston and an expansion cylinder with a built-in expansion piston coaxially adjacent to each other, and an expansion piston drive rod passes through the compression piston and drives the expansion piston by a drive mechanism. There is a Stirling cycle refrigerator that moves reciprocally in conjunction with the reciprocating movement of a compression piston, and compressed refrigerant is expanded in an expansion space at the other end of an expansion cylinder via a radiator and a regenerator.

In a known Stirling cycle refrigerator of this type, for example, the one disclosed in U.S. Pat. The phase is advanced by 90°. Therefore, maximum compression can be obtained at the top dead center of the expansion piston (as seen from the compression operation) and near the neutral position of the compression piston, but in this case, there is a large dead volume of compression space on the outer periphery of the expansion piston protruding into the compression cylinder. This has the disadvantage of reducing the refrigerating capacity of the refrigerator.

An object of the present invention is to provide a Stirling refrigerator which eliminates the above drawbacks by reducing the dead volume of the compression space.According to the present invention, in the Stirling cycle refrigerator of the type described at the beginning, the compression cylinder A Stirling cycle refrigeration system characterized in that the adjacent end of the expansion cylinder is closed by a flange through which the expansion piston drive rod is sealed, thereby forming a compression space within the compression cylinder that is compressed only according to the reciprocating motion of the compression piston. machine is provided.

EMBODIMENT OF THE INVENTION Hereinafter, one embodiment of the Stirling cycle refrigerator 10 according to the present invention will be described with reference to the accompanying drawings. An expansion piston 1 is located inside the expansion cylinder 11.
The piston 12 and the inner wall of the cylinder 11 are sealed by a piston cylinder 13. An intermediate flange 14 and a bottom flange 15 extend radially outward from the side wall of the cylinder 11 . A flange 16a of a cup-shaped housing 16 is bolted to the upper surface of the intermediate flange 14 with bolts 17, and the housing 16 surrounds the outer periphery and upper end of the expansion cylinder 11. An expansion space 18 whose volume changes as the piston 12 reciprocates is formed between the expansion piston 12 and the housing head 16b, and a regenerator 19 filled with a wire mesh is provided between the cylinder 11 and the housing 16. There is.

The intermediate flange 14, the bottom flange 15, and the outer ring 20 constitute a heat radiator 21, and the cooling water filled in the container absorbs heat from the pipe 22 passing through both flanges 14 and 15. It absorbs heat from the flowing working gas (refrigerant) such as hydrogen or helium.

The bottom end of cylinder 11 (i.e. compression cylinder 2
9) is closed by an extension 23 of the bottom flange 15, by which the space between the expansion piston 12 and the compression piston 24 is closed on the expansion piston 12 side. It is divided into a buffer space 25 and a compression space 26 on the compression piston 24 side. This cylinder closing portion 23 has a rod 2 screwed onto the expansion piston 12.
7 is penetrated in a sealed state. rod 2
7 and the expansion piston 12 includes a buffer chamber 2.
A gas vent hole 28 is provided for venting the gas inside 5.

The compression piston 24 that reciprocates within the compression cylinder 29 consists of an upper portion 30 that approximately matches the inner diameter of the cylinder 29 and a lower small diameter portion 31 that is smaller in diameter than this portion, and a rod 27 for driving the expansion piston 12. A through hole 33 is provided in the center. The lower end of the rod 27 is a cap nut 34 that slides within the through hole 33, and a pair of spherical bearings 35 fitted inside the rod 27 to pivotably clamp the spherical journal 37 of the connecting rod 36. ing. There is a notch 3 on the side of the bag nut 34.
8 is provided to allow the gas that has passed through the gas vent hole 28 in the rod 27 to escape to the crank chamber 39 below. A pair of pins 40 are fixed to the side surface of the lower small diameter portion 31, and an end of the connecting rod 41 is fixed to each pin 40.

A piston ring (sealing material) 24a is fitted on the outer periphery of the upper part 30 of the compression piston 24, and a sealing material 24b for sealing with the rod 27 is fitted in the center of the upper part 30. .

A drive device 50 that drives this Stirling cycle refrigerator 10 includes an electric motor 51, a planetary reducer 52 that lowers the rotation speed of this motor 51, and a carrier crank 54 to which a planetary gear 53 of this planetary reducer 52 is attached. , this carrier crank 5
4, a pair of compression piston drive connecting rods 41 with an eccentric ring 56 mounted on the crank pin 55, and a pair of compression piston drive connecting rods 41 with an eccentric ring mounted on an eccentric cam 57 on the crank pin 55. and a connecting rod 41. The rotational movement of the motor 50 is decelerated by the reducer 52 and the rotational movement of the motor 50 is reduced by the crank pin 5.
5 rotates around the abort axis C. The expansion piston 12 is configured to advance in stroke by 90 degrees than the compression piston 24 by an eccentric cam 57.

Stirling cycle refrigerator 10 according to the present invention
To explain the operation, the compression piston 24 located at the bottom dead center in the figure is raised by the connecting rod 41 and compresses the working gas in the compression space 26. piston 2
Since the top dead center of No. 4 coincides with the upper end of the compression cylinder, the dead volume of the compression space 26 is approximately zero. The compressed working gas flows into the regenerator 19 and the expansion space 18 through the pipe 22 in the radiator 21 . After that, the expansion piston 12 descends, and the regenerator 1
9 and the working gas in the expansion space 18 expands, generating a low temperature in the regenerator 19. Expansion piston 12
rises after reaching the bottom dead center and returns the working gas in the expansion space 18 to the compression space 26 through the regenerator 19 and the pipe 22. The refrigerator 10 generates a low temperature in the regenerator 19 by repeating the above cycle.

The structure and operation of the present invention are as described above. By dividing the space between the expansion piston 12 and the compression piston 24 into closed sections, the dead volume is significantly reduced, the compression ratio becomes large, and the refrigeration output increases. did.

[Brief explanation of the drawing]

The accompanying drawing is a side sectional view showing a Stirling cycle refrigerator according to the present invention. 10... Refrigerator, 11... Expansion cylinder, 12
...Expansion piston, 16...Housing, 18...
...expansion space, 19...regenerator, 21...radiator,
23... Closing part, 24... Compression piston, 25...
... Buffer space, 26... Compressed space, 29...
compression cylinder.

Claims (1)

[Scope of Claims] 1 A compression cylinder containing a compression piston and an expansion cylinder containing an expansion piston are coaxially adjacent to each other, and an expansion piston driving rod passes through the compression piston and drives the expansion piston to the compression piston by a drive mechanism. In a Stirling cycle refrigerator, the compressed refrigerant is expanded in an expansion space at the other end of the expansion cylinder through a radiator and a regenerator, the end of the compression cylinder adjacent to the expansion cylinder. A Stirling cycle refrigerator characterized in that the expansion piston driving rod is sealed by a flange passing through the cylinder, thereby forming a compression space in the compression cylinder that is compressed only according to the reciprocating motion of the compression piston.