JPS6353468B2 - - 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 increased refrigeration efficiency.

Refrigerators using the Stirling cycle are theoretically efficient and are desired to be put into practical use, with a compression chamber equipped with a refrigerant compression piston and an expansion chamber equipped with an expansion piston that expands the refrigerant compressed in the compression chamber. and a drive device for driving the compression piston and the expansion piston.

In the above-mentioned Stirling cycle refrigerator, the Rhombic drive mechanism that reciprocates the compression piston and expansion piston with a constant phase difference is composed of an integral crank. However, the axial length becomes longer, and as a result, the size of the drive device becomes larger. There are also systems in which the drive mechanism of the refrigerator is driven by an external prime mover, such as a motor, via a speed reducer, but in this case, there is a drawback that it is not possible to completely seal the bearing part of the connecting shaft that passes through the housing. . Furthermore, in conventional refrigerators, maximum compression is obtained near the top dead center of the expansion piston (as viewed from the compression operation) and the neutral position of the compression piston; This has the disadvantage that a large dead volume compressed space is generated and the refrigerating capacity of the refrigerator is reduced.

An object of the present invention is to provide a Stirling cycle refrigerator that eliminates the above-mentioned drawbacks. That is, the present invention provides a Stirling cycle refrigerator of the type described above, in which the end of the compression cylinder adjacent to the expansion cylinder is closed by a flange through which the expansion piston drive rod is sealed, thereby creating a compression space that is compressed only according to the reciprocating motion of the compression piston. The input rotary shaft connected to the output of the prime mover is connected to the sun gear of a planetary reducer formed in the compression cylinder and the ring gear fixed to the housing, and the carrier crank of the planetary gear is connected to a crank pin eccentric with respect to its axis. a circular eccentric cam having a first eccentric ring fixed to the crank pin and a second eccentric ring fixed to the outer periphery; The entire drive system including the drive system, the prime mover, and the planetary reduction mechanism is connected to the housing of the refrigerator. The above-mentioned problem is solved by housing the device in a sealed manner in a housing integral with the device.

An embodiment of the present invention will be described below with reference to the accompanying drawings. The Stirling cycle refrigerator according to the present invention mainly includes a refrigeration device 10 and a drive device 50 for driving the refrigeration device 10.

The refrigeration system 10 mainly includes an expansion piston 12, a regenerator 19, a radiator 21, and a compression piston 24. The expansion piston 12 is fitted into the expansion cylinder 11 so as to be able to reciprocate, and the piston 12 and the inner wall of the cylinder 11 are sealed by a piston ring 13. An intermediate flange 14 and a bottom flange 15 extend radially outward from the side wall of the cylinder 11 . On the upper surface of the intermediate flange 14,
A flange 16a of the cup-shaped housing 16 is fastened with a bolt 17, and the housing 16 surrounds the outer periphery and upper end of the expansion cylinder 11. Expansion piston 12 and housing head 16b
An expansion space 18 whose volume changes with the reciprocation of the piston 12 is formed between the cylinder 11 and the housing 16, and a regenerator 19 filled with a wire mesh is provided between the cylinder 11 and the housing 16.

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 include a buffer chamber 2.
A gas vent hole 28 is provided for venting the gas inside 5.

The compression piston 24, which 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 includes 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 100 of the connecting rod 95. ing. A notch 38 is provided on the side surface of the cap nut 34 to open the gas vent hole 28 in the rod 27.
The gas that has passed through is released to the crank chamber 39 below. A pair of pins 40 are fixed to the side surfaces of the lower small diameter portion 31, and an end of a connecting rod 90 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. .

Next, the drive device 50 will be explained. The drive device 50 is perpendicular to the refrigeration device 10, and has an L-shaped structure as a whole. The drive device 50 mainly includes a prime mover 60, a planetary reducer 70 connected to the prime mover 60, a carrier crank 80 fixed to a planetary gear 71 of the planetary reducer 70, and a crank pin 83 of the carrier crank 80. a connecting rod 90 that is attached to and reciprocates the pistons 12, 24 of the refrigeration device 10;
95, and a housing 110 that seals and accommodates the above components.

The prime mover 60 located at the left end of the drive device preferably includes an electric motor, such as a DC motor, an AC synchronous motor, an AC induction motor, an AC commutator motor,
A dual-purpose AC/DC motor is used. This motor 60
rotary output shaft 6 supporting a rotor 61 of
2 is rotatably supported by bearings 63 on the left and right sides, and its right end is spline-coupled to a sun gear 72 of a planetary reducer 70 as shown in FIG.

The planetary reducer 70 has a sun gear 72 rotated by an output shaft 62, a ring gear 74 fixed to the housing 110 by a bolt 73, and a ring gear 74 that is meshed between these gears 72 and 74. The planetary reducer 70 is connected to a crank carrier 80 by a pin 75. It consists of three planetary gears 71 that are rotatably connected. Planetary reducer 7
0 has the above configuration, so the output shaft 6
2, that is, the rotational motion of the sun gear 72 is transmitted to the carrier crank 80 in the same direction at a constant reduction ratio.

The carrier crank 80 is composed of a disk-shaped portion 82 to which the planetary gear 71 is attached, and a crank pin 83 that protrudes from the disk-shaped portion 82 and has an eccentric axis Y eccentric from the rotation axis X. Carrier crank 80 as shown in FIGS. 1 and 2
The outer periphery of is supported by a ball bearing 84. Although it is possible to omit the bearing 84, by providing such a bearing, the rotation of the carrier 80 is stabilized. At the right end of the crank pin 83 is a crank 85.
is fixed by bolt 86, and crank pin 83
The right end is supported so that it can rotate freely.

A pair of connecting rods 9 are provided on both sides of the crank pin 83.
The other end of these connecting rods 90 is pivotally connected to the compression piston 24 of the refrigeration system 10 via a pin 40.
With such a mechanism, when the crank pin 83 turns around the rotation axis X, the compression piston 24 reciprocates within the compression cylinder 29. These connecting rods 9
A circular eccentric cam 96 is fixed between the two eccentric wheels 91 by a key 97. This eccentric cam 9
The center Z of 6 is eccentric by a predetermined amount with respect to the rotation axis X of the carrier crank 80, as shown in FIG.
The phase of the reciprocating movement of the expansion piston 12 is arranged to lead the phase of the compression piston 24 by about 90 degrees. A ball bearing 9 is provided on the outer periphery of this eccentric cam 96.
Eccentric wheel (second eccentric wheel) of connecting rod 95 through 8
99 is fitted, and the other end of the connecting rod 95 forms a spherical journal 100.

Eccentric wheel 99 and connecting rod 95 convert rotational motion of crank pin 83 into reciprocating motion of expansion piston 12, which reciprocating motion is 90° ahead of compression piston 24 due to eccentric cam 96, resulting in a Stirling cycle. The piston stroke necessary for refrigeration work can be obtained.

A housing 110 that seals and accommodates the drive device 50 is a housing 1 that accommodates the prime mover 60.
10a, an intermediate housing 110b that accommodates the planetary reducer 70, a side plate 110c that supports the crank 85, and a bottom plate 110d located below the crank pin 83, which are integrally connected to each other by an O-ring 115 and a bolt 116. Moreover, the intermediate housing is connected to the compression cylinder 29 of the refrigeration system 10 and the O-ring 1.
17 and bolts 118 in a sealed state. Therefore, the housing 11 of the drive device 50
0 provides a sealed space for the working gas in the device 10 together with the housing of the refrigeration device 10, that is, the compression cylinder 29, but since the rotating shaft does not pass through the housing 110 of the drive device 50, the sealing performance is poor. It has further improved.

The configuration of the present invention is as described above, and by employing the planetary reducer 70 and the carrier crank 80, the overall length of the device is shortened, and the carrier crank 80 and the eccentric cam 96 provide a freewheel effect. has become unnecessary. Furthermore, as described above, since the entire drive mechanism is housed within the housing, the sealing performance against the working gas is improved without using a special sealing device.

As described above, in the present invention, the compression piston and the expansion piston can be driven by one small reduction drive mechanism, and both pistons are crank-driven in the direction perpendicular to the rotation axis, allowing for easy and smooth operation. be.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of a Stirling refrigerator drive device according to the present invention, and FIG.
A schematic diagram showing the gear train of the drive device shown in the figure, FIG. 3 is A-A in FIG.
4 is a sectional view taken along the line B-B of FIG. 1 showing the installation of the connecting rod that drives the compression piston, and FIG. 5 is a sectional view showing the installation of the connecting rod that drives the expansion piston. FIG. 2 is a sectional view taken along line CC in FIG. 1; 10... Refrigeration device, 50... Drive device, 60...
...Motor, 70...Planetary reducer, 80...Carrier crank, 90,95...Connecting rod, 110...
housing.

Claims (1)

[Claims] 1. A compression cylinder with a built-in compression piston and an expansion cylinder with a built-in expansion piston are coaxially adjacent to each other, and an expansion piston drive rod passes through the compression piston and causes the expansion piston to cooperate with the reciprocating motion of the compression piston by a drive mechanism. In a Stirling cycle refrigerator, the compressed refrigerant is expanded in the expansion space at the other end of the expansion cylinder through a radiator and a regenerator, and an expansion piston driving rod connects the end of the compression cylinder adjacent to the expansion cylinder. A sealed and penetrating flange forms a compression space in the compression cylinder that is compressed only according to the reciprocating motion of the compression piston, and the ring gear is connected to the output of the prime mover to the sun gear of a planetary reducer fixed to the housing. It has a planetary reduction mechanism in which a crank pin eccentric to the shaft is fixed to a carrier crank of a planetary gear, a first eccentric ring is supported on the crank pin, and a first eccentric ring is mounted on the outer circumference. a drive device having a fixed circular eccentric cam bearing a second eccentric, and driving the compression piston and the expansion piston via connecting rods connected to the first and second eccentrics, respectively; A Stirling cycle refrigerator, characterized in that the entire drive device including the drive device, the prime mover, and the planetary reduction mechanism is hermetically housed in a housing integral with a housing of the refrigerator.