Refrigeration – Gas compression – heat regeneration and expansion – e.g.,...
Reexamination Certificate
1999-11-02
2001-08-28
Capossela, Ronald (Department: 3744)
Refrigeration
Gas compression, heat regeneration and expansion, e.g.,...
C062S520000
Reexamination Certificate
active
06279325
ABSTRACT:
BACKGROUND OF THE INVENTION
(I) Field of the Invention
The present invention relates to a Stirling cycle device which can be used for refrigerating or cooling in all industrial fields of industrial apparatuses of food distribution, environmental test, medicine, biological industry, semiconductor manufacture, and the like, or household apparatuses.
(ii) Description of the Related Art
In recent years, a Stirling cycle refrigerator, hereafter referred to generallt as “refrigerator”, has been highlighted as a refrigerating device using a substitute for Freon in earth environmental problems, or as a refrigerator whose operation temperature is in a broader range than that of a conventional cooling device. Therefore, the refrigerator can be applied to the apparatuses utilizing cooling heat for business or household use such as a freezer, a refrigerator, and a throw-in type cooler, and the cooling heat utilizing apparatuses of all industrial fields such as a low-temperature fluid circulator, a low-temperature isothermal unit, an isothermal tank, a heat shock test device, a freezing drier, a thermal property test device, a blood/cell storage-device, a cold cooler, and other various cooling heat devices. Furthermore, the refrigerator is compact, high in result coefficient, and excellent in energy efficiency.
FIG. 1
is an entire schematic view of a conventional general Stirling cycle refrigerator
1
, and in a housing
2
, crank portions
5
,
6
of a crank shaft
4
operated by a motor
3
are connected to a compression piston rod
9
and an expansion piston rod
10
via cross guide heads
7
,
8
. Via these compression piston rod
9
and expansion piston rod
10
, a compression piston
11
and an expansion piston
12
reciprocate with a phase difference in a compression cylinder
13
and an expansion cylinder
14
, respectively. Thereby, operating gas is compressed and expanded. Additionally, by a radiating heat exchanger (high-temperature side heat exchanger)
18
and a cooling heat exchanger (low-temperature side heat exchanger)
19
disposed between a high-temperature chamber (compression chamber)
15
of the compression cylinder
13
and a low-temperature chamber (expansion chamber)
16
of the expansion cylinder
14
via a regenerator
17
, heat exchange is performed between a radiating refrigerant and a cooling heat refrigerant, and the operating gas.
Here, there arises a problem, which is so-called oil rising, that oil or oil mist rises from a crank chamber along the piston rods
9
,
10
. For the oil rising, after entering the compression and expansion cylinders, the oil or oil mist adheres to inner surfaces, or is carbonized by heat so that the performance and durability of the refrigerator are remarkably deteriorated. To solve the oil rising problem, in a conventional art, the compression piston rod
9
and the expansion piston rod
10
are sealed by oil seals
20
,
21
.
Additionally, the oil seals are variously developed in structures and materials, but they are not necessarily sufficient in sealing performance or durability. Moreover, a roll socks type seal system has been proposed, whose durability cannot be said to be sufficient in the present situation.
Moreover, when the Stirling cycle refrigerator is operated, temperature rises, and inner pressure rises in a crank chamber
26
. The pressure rise of the crank chamber applies a mechanical burden to the oil seal, and causes deterioration. There arises another problem that the pressure promotes the oil rising, and adversely affects the performance.
Moreover, the reciprocating movement of the compression and expansion pistons generates a pressure fluctuation on the side of a back surface, and adversely affects the oil seals.
An object of the present invention is to solve problems peculiar to the Stirling cycle refrigerator comprising the above-described refrigerator, and the problems of the present invention are as follows:
(1) The oil rising is prevented, long-life piston rod oil sealing bellows are realized, and the performance and life of the Refrigerator are enhanced.
(2) For the pressure rise accompanying the temperature rise of the crank chamber, even when a general oil seal is employed, deterioration or oil rising cannot be prevented. Moreover, even when the oil sealing bellows are employed, inner and outer pressure differences are generated to adversely affect the bellows themselves and the performance of the refrigerator. The pressure rise accompanying the temperature rise of the crank chamber is solved by employing a buffer tank which has pressure adjusting bellows.
(3) The problem of pressure fluctuation generated on the side of the back surface of the compressing or expanding piston which adversely affects the oil seal or the refrigerator performance is solved by employing the buffer tank provided with or without the pressure adjusting bellows.
(4) The problem of the pressure fluctuation generated on the back surface side of the piston is solved by utilizing a space in the housing having the crank chamber. Specifically, the problem is solved by connecting the back surface side of the piston to the space in the housing having the crank chamber via an oil trapping device. In this case, a constricting device for adjusting the oil trapping device may also be used together (arranged in series for use).
SUMMARY OF THE INVENTION
To solve the problems, according to the present invention, there is provided a Stirling cycle refrigerator, comprising: a housing having a crank chamber; a cylinder disposed above and adjacent to the crank chamber; a piston for reciprocating in the cylinder to compress or expand operating gas, or a displacer; a piston rod operatively connected to a crank in the crank chamber and having one end connected to the piston, or the displacer; and an oil seal disposed in an opening of a top of the crank chamber through which the piston rod is passed. In the Stirling cycle refrigerator, the oil seal comprises oil sealing bellows whose tip end is fixed to the piston rod in the cylinder and whose base end is fixed to a peripheral edge of the opening of the top of the crank chamber provided with the piston rod passed therethrough. By disposing the oil sealing bellows, oil is inhibited from entering the cylinder via a space in the housing.
Between a space on the side of a back surface of the piston for compressing or expanding the operating gas and the space in the housing, a buffer tank for absorbing a pressure fluctuation in the space on the back surface side, and a pressure rise in the housing is connected via connecting means. Inside the buffer tank, pressure adjusting bellows are disposed to divide the buffer tank into a chamber on the side of an opening of the pressure adjusting bellows and a chamber on the side of a closing wall, and the chamber on the opening side and the chamber on the closing wall side may be connected to either one of the space on the back surface side of the piston and the space in the housing.
Additionally, the space on the back surface side of the piston for compressing-or expanding the operating gas and the space in the housing may be connected via an oil trapping device to absorb the pressure fluctuation of the space on the back surface side.
Moreover, in the space on the back surface side of the piston for compressing or expanding the operating gas, the buffer tank for absorbing the pressure fluctuation of the space on the back surface side is connected via the connecting means. Between the buffer tank and the space in the housing, the oil trapping device, or the oil trapping device connected to a pressure adjusting constriction device may be disposed, so that pressure adjustment can be performed in the space on the back surface side of the piston for compressing or expanding the operating gas, and the space in the housing.
Furthermore, as the oil seal, in addition to the oil sealing bellows, an annular pressure-resistant oil seal pressed into contact with the piston rod is disposed in the opening of the top of the crank chamber. Between the space on the back surface sid
Fukuda Eiji
Inoue Takashi
Kakinuma Hirotaka
Komatsubara Takeo
Koumoto Nobuo
Capossela Ronald
Darby & Darby
Sanyo Electric Co,. Ltd.
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