Lubrication – Systems – Rotary compressor
Reexamination Certificate
2000-06-23
2002-09-17
Kim, Chong H. (Department: 3682)
Lubrication
Systems
Rotary compressor
C184S006180, C092S160000
Reexamination Certificate
active
06450297
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a hermetic compressor, more particularly, a hermetic compressor in which an oil supplying hole for supplying oil between a piston and a cylinder block is formed to pass through an inner wall of( a piston hole in which a lateral pressure of the piston is generated so as to improve a lubricating action for the piston.
2. Description of the Related Art
As shown in
FIG. 1
, a conventional hermetic compressor comprises a compressing instrument
20
and an electric instrument
30
.
The compressing instrument
20
comprises a bearing
21
which is upright mounted at a center portion of a sealed housing
10
, a crankshaft
23
which is rotatably mounted in the bearing
10
and provided with a eccentric shaft
22
at a lower portion thereof, a cylinder block
24
which is fixedly disposed at a lower portion of the bearing
21
, a connecting rod
25
which is coupled to the eccentric shaft
22
of the crankshaft
23
, a piston
26
which is mounted at an end of the connecting rod
25
so as to linearly reciprocate within the cylinder block
24
, and a head cover
27
which is disposed at an end of the cylinder block
24
and formed with a suction and discharge valve (not shown) as means for sucking and discharging refrigerant.
And, the electric instrument
30
comprises a rotor
31
which is coupled to the crankshaft
23
so as to rotate along with the crankshaft
23
, and a stator
32
which is disposed around the rotor
31
in the sealed housing
10
so as to generate an electromagnetic force by which the rotor
31
is rotated.
At a lower portion in the sealed housing
10
, there is provided cooling oil
0
. The cooling oil is supplied to each sliding member by a lubricating means so as to prevent a friction and wear between the sliding members.
In an example of the lubricating means, as shown in
FIG. 2
, there is formed a small diameter portion
41
at a middle portion of the crankshaft
23
which is inserted into the bearing
21
. Between the small diameter portion
41
and an inner wall of the bearing
21
, there is formed an oil bank in which the oil
0
is stored. A lower oil supplying groove
43
and an upper oil supplying groove
44
are respectively formed at each outer face of a lower and upper portions of the crankshaft
23
with the small diameter portion
41
in the center. An oil supplying hole
45
, which is communicated with the lower oil supplying groove
43
, is formed within the eccentric shaft
22
which is provided to the lower portion of the crankshaft
23
. The oil supplying hole
45
is connected with an oil pickup tube
46
. Further, at an edge of the upper end of the bearing, there is formed a guiding groove
47
for guiding the oil
0
.
In the conventional hermetic compressor as described above, if power source is applied to the compressor, the rotor
31
is rotated by the electromagnetic action between the stator
32
and the rotor
31
. The crankshaft
23
, which is coupled to the rotor
3
l, is rotated. Due to the rotation of the crankshaft
23
, the eccentric shaft
22
disposed at the lower portion or the crankshaft
23
is also rotated. Therefore, the piston
26
, which is coupled to the end of the connecting rod
25
, is linearly reciprocated in the cylinder block
24
so that the suction, compression and discharge operations of the refrigerant are performed.
Meanwhile, when the crankshaft
23
is rotated, the oil
0
stored in the lower portion of the sealed housing
10
is sucked through the oil pickup tube
46
which is coupled to the lower portion of the eccentric shaft
22
. The sucked oil
0
is moved upward through the oil supplying hole
45
and the oil supplying groove
43
and supplied to the outer face of the bearing
21
. The sucked oil
0
is also supplied between the piston
26
and cylinder block
24
so that the piston
26
is smoothly reciprocated.
As described above, when the crankshaft
23
is rotated, the oil
0
is supplied to each sliding members of the compressor and then returned to the lower portion of the sealed housing
10
, repeatedly.
In the conventional hermetic compressor, however, when the refrigerant is compressed, the compression force of the piston
26
is characterized by a longitudinal component force Fv and a lateral component force Fs. At this time, a clearance between the inside wall of the cylinder block
24
and the outside wall of the piston
26
is different according to the positions where the lateral component force Fs is applied or not applied (Cs
1
>>Cs
2
).
Therefore, when manufacturing the piston
26
and the cylinder block
24
, if a machining error is generated and a foreign matter is introduced therein, an oil film is instantaneously and repeatedly destroyed in a portion between the outer wall of the piston
26
and the inner wall of the cylinder block
24
, on which the lateral component force is exerted. Therefore, the lubricating action is not performed smoothly so that the friction and wearing is generated in the portion on which the lateral component force is exerted.
In the conventional mechanism, as shown in
FIG. 4
, since the oil
0
sucked through the oil suppling hole
45
is supplied to oil hole
24
a
formed at a center portion of the cylinder block
24
corresponding to a center of the piston
26
, there is a problem that the oil
0
is not supplied sufficiently to the portion on which the lateral component force is exerted.
Further, there is other problem that an internal temperature of the compressor is increased by a frictional heat so as to lower the performance and the compressing implement is deformed so as to lower the confidence thereof.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a hermetic compressor which has an improved lubricating structure of the piston in order to prevent the friction and wear between the piston and the cylinder block.
To achieve the above objects and other advantages, there is provided a hermetic compressor in which an oil hole is formed in the cylinder block so as to penetrate through a piston hole of the cylinder block so that oil sucked through an oil supplying hole of a crankshaft by rotation of the crankshaft is passed through the piston hole when the oil is dispersed, characterized in that the oil hole is formed at an interior wall of the piston, on which a lateral component force is exerted when the piston is reciprocated in the piston hole of the cylinder block.
Preferably, the oil hole has a larger upper diameter which is at an upper portion of the piston hole than a lower diameter which is at a lower portion of the piston hole.
REFERENCES:
patent: 5118263 (1992-06-01), Fritchman
patent: 5191863 (1993-03-01), Hagiwara
patent: 5313875 (1994-05-01), Kadlicko
patent: 5839351 (1998-11-01), Nakada
patent: 6089352 (2000-07-01), Kim et al.
patent: 6135008 (2000-10-01), Soupal et al.
patent: 6138634 (2000-10-01), Kusche et al.
Burns Doane , Swecker, Mathis LLP
Kim Chong H.
Samsung Kwangju Electronics Co., Ltd.
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