Refrigeration – Gas compression – heat regeneration and expansion – e.g.,...
Reexamination Certificate
2001-01-02
2002-10-22
Capossela, Ronald (Department: 3744)
Refrigeration
Gas compression, heat regeneration and expansion, e.g.,...
C060S520000
Reexamination Certificate
active
06467276
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a pulse tube refrigerator, and in particular, to a pulse tube refrigerator which is capable of minimizing vibration occurring during the operation, and having a simple overall structure.
2. Description of the Prior Art
In general, a pulse tube refrigerator is one type of cryogenic refrigerator having a low-vibration and high-reliability which is used for cooling small size electronic parts or super-conductors. A Stirling refrigerator and a GM refrigerator are widely used as the cryogenic refrigerator.
As depicted in
FIG. 1
, the conventional pulse tube refrigerator comprises a compressor
10
for compressing operating gas by generating a linear reciprocation operating force, a pulse tube
20
for releasing heat on the compressing part
21
and absorbing external heat on an expanding part
22
while the operating gas is compressed and expanded at both ends of the tube by the operation of the compressor
10
, an inertance tube
30
for generating phase difference between mass flow and pressure pulsation of the operating gas fluctuated by connecting to the pulse tube
20
and at the same time achieving the heat balance, a reservoir
40
connected to the end of the inertance tube
30
, a regenerating unit
50
connected between the pulse tube
20
and after-cooler
60
in order to store and release sensible heat of the operating gas passing the pulse tube
20
by being sucked and compressed at the compressor
10
, and an after-cooler
60
placed between the regenerating unit
50
and compressor
10
for cooling the operating gas pushed by the compressor
10
before it reaches the regenerating unit
50
.
The compressor
10
for compressing and sucking the operating gas while generating the linear reciprocation operating force comprises a sealed casing
11
having the inner area covering housings
11
b
,
11
c
, an upper housing
11
a
closely combined to the upper outer circumference of the sealed casing
11
having a cylinder unit on the center portion, a middle housing
11
b
which is placed inside of the sealed casing
11
and its upper surface is closely combined to the lower surface of the upper housing
11
a
, an elastic supporting member
15
is combined inside of it, an operating motor
12
having a piston
14
inserted into the cylinder unit
13
is fixedly installed on it, and a lower housing
11
c
which is placed inside of the sealed casing
11
and its upper surface is closely combined to the lower surface of the middle housing
11
b
, the elastic supporting member
15
is combined to it.
The operation of the conventional pulse tube refrigerator will now be described.
First, when the compressor
10
compresses and sucks the operating gas by being applied power, the operating gas flows into the pulse tube
20
after passing the after-cooler
60
and regenerating unit
50
, is discharged into the inertance tube
30
, repeats the reverse operation, while repeating the above operation, the phase difference is generated between the mass flow and pressure pulsation, according to this the compressing and expanding occur at the compressing part
21
and expanding part
22
of the pulse tube
20
, temperature on the expanding part
22
of the pulse tube
20
lowers drastically.
The inertance tube
30
and reservoir
40
accelerate the compressing and expanding of the operating gas at the pulse tube
20
, the after-cooler pre-cools the operating gas pushed from the compressor
10
, and the regenerating unit
50
stores/releases the sensible heat of the operating gas reciprocating between the compressor
10
and pulse tube
20
.
While repeating the above-mentioned process, the expanding part
22
of the pulse tube
20
is cooled continually, and accordingly the cryogenic refrigeration is obtained.
However, in the conventional pulse tube refrigerator, vibration occurs while the operating gas is compressed by the piston receiving the linear reciprocating motion of the operating motor installed in the compressor, and it causes the vibration noise.
In addition, because the reservoir constructed as the additional part is connected to the inertance tube having a certain length, the overall size of the pulse tube refrigerator is big, lots of manufacturing costs are required, it is difficult to transfer, and it requires lots of installation area.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a pulse tube refrigerator which has a simple overall structure.
Another object of the present invention is to provide the pulse tube refrigerator having a vibration absorbing unit which efficiently reduces vibration occurring while compressing operating gas.
Another object of the present invention is to provide the pulse tube refrigerator having a combining structure of a sealing member which improves the efficiency of the vibration absorbing unit.
In order to achieve the objects, the pulse tube refrigerator according to the present invention comprises a compressor having a sealed casing with a cylinder and an opening at one end thereof, a motor mounted in the sealed casing, and a piston operatively attached with the motor to compress and expand an operating gas via the opening, an after-cooler connected with the compressor in order to cool the operating gas discharged from the compressor, a regenerating unit connected with the after-cooler in order to store and release latent heat of the operating gas reciprocating between the compressor and reservoir formed at an outer surface of the sealed casing and a cover integrally attached to the sealed casing, a pulse tube connected with the regenerating unit, the pulse tube having a cryogenic portion formed thereon, an inertance tube connected with the pulse tube in order to accelerate a formation of the cryogenic portion and connected with the cover, and a vibration absorbing unit which is placed inside of the reservoir and is fixedly attached to the sealed casing in order to reduce the vibration occurring due to the operation of the motor.
In addition, in order to achieve the above-mentioned objects, the pulse tube refrigerator according to the present invention comprises a compressor having a sealed casing with a cylinder and an opening at one end thereof, a motor mounted in the sealed casing, and a piston operatively attached with the motor to compress and expand an operating gas via the opening, an after-cooler connected with the compressor in order to cool the operating gas discharged from the compressor, a regenerating unit connected with the after-cooler in order to store and release latent heat of the operating gas reciprocating between the compressor and a reservoir formed at an outer surface of the sealed casing a a cover attached to the sealed casing, a pulse tube connected with the regenerating unit, the pulse tube having a cryogenic portion formed thereon, an inertance tube connected with the pulse tube in order to accelerate a formation of the cryogenic portion and connected with the cover, a sealing member which is placed between the cover and casing in order to prevent leakage of the operating gas, and a vibration absorbing unit placed inside of the reservoir and fixedly attached to the sealing member in order to reduce the vibration occurring due to the operation of the motor.
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patent: 4739634 (1988-04-01), Watanabe
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patent: 4854131 (1989-08-01), Sakitani et al.
patent: 5090206 (1992-02-01), Strasser
patent: 5913392 (1999-06-01), Eckel et al.
patent: 5966943 (1999-10-01), Mitchell
patent: 6094921 (2000-08-01), Zhu et al.
patent: 3816033 (1989-12-01), None
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patent: 111032 (1984-06-01), None
patent: WO 90 04144 (1990-04-01), None
patent: 1031728 (2000-08-01), None
patent: 59 032754 (1984-02-01), None
Chung Woo Suk
Kim Sung Tae
Birch & Stewart Kolasch & Birch, LLP
Capossela Ronald
LG Electronics Inc.
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