Pumps – Expansible chamber type – Having pumping chamber pressure responsive distributor
Reexamination Certificate
1999-12-20
2001-11-20
Walberg, Teresa (Department: 3742)
Pumps
Expansible chamber type
Having pumping chamber pressure responsive distributor
C137S856000
Reexamination Certificate
active
06318980
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a refrigerant compressor used for an automotive air-conditioning system. More particularly, the present invention relates to shapes of suction holes and discharge holes provided in a valve plate of a compressor.
2. Description of the Related At
A description of the structure and operation of a refrigerant compressor for an automotive air conditioning system follows. Referring to
FIG. 1
, a conventional compressor
100
is depicted. Compressor
100
comprises front housing
30
, housing
27
, valve plate
1
, and rear housing
32
. Along the central axis of compressor
100
is provided a drive shaft
34
, which is supported rotatably by needle bearings
35
and
36
. Within housing
27
, cam rotor
37
which is fixed to drive shaft
34
engages the inner wall of front housing
30
via thrust bearing
38
. Cam rotor
37
rotates when drive shaft
34
is rotated. Hinge mechanism
39
couples cam rotor
37
with inclined plate
40
. Inclined plate
40
rotates with cam rotor
37
. Wobble plate
43
engages with inclined plate
40
via thrust bearing
41
and needle bearing
42
. A wobbling motion is induced in inclined plate
40
, so that inclined plate
40
wobbles while rotating. This motion of inclined plate
40
transfers to wobble plate
43
. Rotation of wobble plate
43
is inhibited by engagement with a guide bar
44
. Therefore, only the wobbling component of the motion of inclined plate
40
is transferred from inclined plate
40
to wobble plate
43
. Wobble plate
43
has a wobbling motion, but does not rotate with drive shaft
34
. Rod
45
is connected by spherical coupling to wobble plate
43
and to a plurality of pistons
46
. When wobble plate
43
wobbles, each of pistons
46
reciprocates in one of a plurality of cylinders
71
.
Suction valve reed
22
, discharge valve reed
2
, and valve retainer
3
are fixed by bolt
47
to valve plate
1
. Suction holes
5
and discharge holes
4
correspond to each piston cylinder
71
. Suction chamber
72
and discharge chamber
70
are formed by valve plate
1
and the rear housing
32
, and are separated by inside partition plate
33
.
When drive shaft
34
is rotated by an external power source (not shown), each piston
46
reciprocates in its respective piston cylinder
71
. When piston
46
is moving leftward in
FIG. 1
, the suction phase is executed, and when piston
46
is moving rightward, the compression phase is executed.
In the suction phase, refrigerant gas in suction chamber
72
is drawn into piston cylinder
71
through suction hole
5
. Due to the pressure variance between suction chamber
72
and piston cylinder
71
, the refrigerant gas in suction chamber
72
flows to suction hole
5
, passes through suction hole
5
, opens suction valve reed
22
, and enters piston cylinder
71
. Suction valve reed
22
prohibits a reverse flow of refrigerant gas into suction chamber
72
during the compression phase.
In the compression phase, the refrigerant gas in piston cylinder
71
is discharged into discharge chamber
70
through discharge hole
4
. Due to the pressure variance between piston cylinder
71
and discharge chamber
70
, the refrigerant gas passes through discharge hole
4
, opens discharge valve reed
2
, and enters discharge chamber
70
. Discharge valve reed
2
prohibits a reverse flow of the refrigerant gas into piston cylinder
71
during the suction phase.
FIG. 2
a
depicts a cross-sectional view of valve plate
1
from the rear housing side of valve plate
1
.
FIG. 2
b
depicts a cross-sectional view of valve plate
1
from the cylinder head side of valve plate
1
. With reference to
FIG. 2
a
, rear housing
32
is fixed to housing
27
by a plurality of bolts
130
. Suction holes
5
and discharge holes
4
are disposed equiangularly around the center CO and correspond to piston cylinders
71
. Suction chamber
72
and discharge chamber
70
are separated by inside partition plate
33
. Discharge valve reed
2
within inside partition plate
33
is substantially star-shaped. The arms of discharge valve reed
2
cover discharge holes
4
. With reference to
FIG. 2
b
, suction valve reed
22
also is substantially star-shaped. Within each arm, a hole
22
h
enables the discharge gas to flow therethrough.
FIG. 3
depicts valve plate
1
as viewed from the side of valve plate
1
facing discharge chamber
70
. Discharge holes
4
and suction holes
5
are disposed equiangularly with respect to the center C of valve plate
1
. FIG.
4
and
FIG. 5
are corresponding radial, cross- sectional views of valve plate
1
of FIG.
1
. Valve reed
2
is fixed between valve plate
1
and valve retainer
3
. Discharge holes
4
have side walls which are substantially perpendicular to the opposing surfaces of valve plate
1
.
FIG.
4
and
FIG. 5
depict valve plate
1
during the compression phase. When the refrigerant gas is discharged from cylinders
71
, it strikes, pushes, and displaces valve reed
2
. The refrigerant gas flows into discharge chamber
70
through a gap created between valve reed
2
and valve plate
1
. When refrigerant gas flow impinges against reed valve
2
in
FIG. 4
, its flow path may be diverted at an angle substantially perpendicular to valve plate
1
. Turbulence in the refrigerant gas flow may be created due to the abrupt change in the direction of flow. Further, a portion of the refrigerant gas flow impinging against valve reed
2
may not enter discharge chamber
70
, and may instead return to piston cylinder
71
. These turbulence effects are indicated by the arrows in FIG.
4
and FIG.
5
. Therefore, turbulence of the refrigerant gas flow may result in flow resistance at discharge hole
4
. Such flow resistance lowers the volumetric efficiency, a primary measure of the performance of compressor
100
. The turbulence of flow also disturbs the motion of valve reed
2
and impedes valve reed
2
from discretely and completely opening and closing. Moreover, the turbulence of flow in discharge holes
4
may cause noise in compressor
100
. Similar problems may occur with respect to suction holes
5
.
Thus, it has long been desired to resolve effectively the problem of the turbulence of refrigerant gas flowing through the suction holes and discharge holes and to suppress noise generated thereby.
SUMMARY OF THE INVENTION
Therefore, a need has arisen to effectively resolve the problem of turbulence of refrigerant gas flowing through the suction holes and discharge holes, so that refrigerant flow is not impeded, and noise is suppressed. It is an object of the present invention to provide a shape for such suction holes and discharge holes in a valve plate of a compressor that improves the volumetric efficiency of the compressor and suppresses noise. It is another object of the present invention to provide shapes of such suction holes and discharge holes that may suppress the occurrence of turbulence of the refrigerant gas flow to lower impedance to refrigerant gas passing through the suction holes or the discharge holes, or both.
A compressor according to the present invention is equipped with a valve plate that has suction passages and discharge passages. Regarding the discharge passages, each of the discharge passages includes a first piston cylinder-side opening having a first piston cylinder-side opening area, a discharge chamber-side opening having a discharge chamber-side opening area, and a sidewall extending between the openings. At least a portion of the discharge passage sidewall is tapered. The discharge chamber-side opening area is greater than the piston cylinder-side opening area. Regarding the suction passages, each of the suction passages includes a second piston cylinder-side opening having a second piston cylinder-side opening area, a suction chamber-side opening having a suction chamber-side opening area, and a sidewall extending between the openings. At least a portion of the suction passage sidewall is tapered. The piston cylinder-side opening area is greater than the su
Kimura Yoshio
Kurihara Masayuki
Noda Tetsuya
Takai Kazuhiko
Uchikado Iwao
Baker & Botts L.L.P.
Fastovsky Leonid
Sanden Corporation
Walberg Teresa
LandOfFree
Shape of suction hole and discharge hole of refrigerant... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Shape of suction hole and discharge hole of refrigerant..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Shape of suction hole and discharge hole of refrigerant... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2613627