U.S. patent application number 12/173369 was filed with the patent office on 2009-03-12 for compressor.
This patent application is currently assigned to CALSONIC KANSEI CORPORATION. Invention is credited to Hiroyuki MAKISHIMA.
Application Number | 20090068000 12/173369 |
Document ID | / |
Family ID | 39863122 |
Filed Date | 2009-03-12 |
United States Patent
Application |
20090068000 |
Kind Code |
A1 |
MAKISHIMA; Hiroyuki |
March 12, 2009 |
COMPRESSOR
Abstract
An air bleeding passage 31 through which an intake chamber 7 and
a crankcase 5 communicate with each other includes at least: a
radial passage 31b which is formed in the driving shaft 10 to be
directed in the radial direction, and which indirectly communicates
with the intake chamber 7; and a radial passage 31a which is formed
in a rotor 21 fixed to the driving shaft 10 by press-fitting to be
directed in the radial direction, and through which the radial
passage 31b in the driving shaft 10 and the crankcase 5 are
communicatively connected to each other. An inlet part 61 of the
radial passage 31a in the rotor 21 is configured as a
cylinder-shaped part 61 protruding from the outer peripheral part
63 thereof, and is placed not to overlap a connecting mechanism 40
in the circumferential direction, the connecting mechanism 40 used
for connecting the rotor 21 and a swash plate 24 to each other.
Inventors: |
MAKISHIMA; Hiroyuki;
(Sano-shi, JP) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
CALSONIC KANSEI CORPORATION
|
Family ID: |
39863122 |
Appl. No.: |
12/173369 |
Filed: |
July 15, 2008 |
Current U.S.
Class: |
415/182.1 |
Current CPC
Class: |
F04B 27/1054 20130101;
F04B 27/109 20130101; F04B 27/1081 20130101 |
Class at
Publication: |
415/182.1 |
International
Class: |
F04D 29/40 20060101
F04D029/40 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 18, 2007 |
JP |
2007-187365 |
Jul 18, 2007 |
JP |
2007-187369 |
Claims
1. A compressor, comprising: a driving shaft (10); a rotor (21,
121) fixed to an outer periphery of the driving shaft (10) by
press-fitting; an intake chamber (7); a crankcase (5); and an air
bleeding passage (31) through which the intake chamber (7) and the
crankcase (5) communicate with each other, wherein the air bleeding
passage (31) comprises: a radial passage (31b, 131b) which is
formed in the driving shaft (10) to be directed in a radial
direction of the driving shaft (10), and which communicates with
the intake chamber (7); and a radial passage (31a, 131a) which is
formed in the rotor (21, 121) to be directed in a radial direction
of the rotor (21, 121), and through which the radial passage (31b,
131b) in the driving shaft (10) and the crankcase (5) are
communicatively connected to each other, and wherein an inlet part
(61, 161) of the radial passage (31a, 131a) in the rotor (21, 121)
is formed as a cylinder-shaped part (61, 161) protruding from an
outer peripheral side (63, 163) of the rotor (21, 121).
2. The compressor according to claim 1, wherein the rotor (21, 121)
is connected to a swash plate (24) provided in the crankcase (5) by
a connecting mechanism (40); and wherein the inlet part (61, 161)
of the radial passage (31a, 131a) in the rotor (21, 121) is placed
in a location where the inlet part (61, 161) does not overlap the
connecting mechanism (40) in a circumferential direction of the
rotor (21, 121).
3. The compressor according to claim 1, wherein an outer peripheral
surface of the cylinder-shaped part (61) includes an undercut part
(61a) which gradually juts out from its base end toward its front
end.
4. The compressor according to claim 1, wherein a passage
cross-section area of the radial passage (31a, 131a) in the rotor
(21, 121) is smaller than that of the radial passage (31b, 131b) in
the driving shaft (10).
5. The compressor according to claim 1, further comprising: a
communicating part (135) through which the radial passage (131a) in
the rotor (121) and the radial passage (131b) in the driving shaft
(10) communicate with each other, and the communicating part (135)
being formed in any one of an outer peripheral surface of the
driving shaft (10) and an inner peripheral surface of the rotor
(121).
6. The compressor according to claim 5, wherein the radial passage
(131a) in the rotor (121) is formed in a location offset from the
radial passage (131b) in the driving shaft (10) in a rotational
direction (R) of the rotor (121); thereby the radial passage (131a)
communicates with the radial passage (131b) through the
communicating part (135).
7. The compressor according to claim 6, wherein the radial passage
(131a) in the rotor (121) is arranged in a location offset from the
radial passage (131b) of the driving shaft (10) in a direction
reverse to the rotational direction (R) of the rotor (121).
8. The compressor according to claim 6, wherein the radial passage
(131a) in the rotor (121) includes a first radial passage (131a1)
and a second radial passage (131a2) which are arranged in the
rotational direction (R) of the rotor (121).
9. The compressor according to claim 8, wherein a passage
cross-section area of a minimum-diameter portion of the second
radial passage (131a2) is set smaller than a passage cross-section
area of a minimum-diameter portion of the first radial passage
(131a1).
10. The compressor according to claim 8, wherein the first radial
passage (131a1) is arranged in a location offset from the radial
passage (131b) of the driving shaft (10) in a direction reverse to
the rotational direction (R) of the rotor (121), and the second
radial passage (131a2) is arranged in a location offset from the
first radial passage (131a1) in the rotational direction (R) of the
rotor (121).
11. The compressor according to claim 8, wherein the second radial
passage (131a2) is tapered in a way that a diameter of the second
radial passage (131a2) becomes progressively larger toward its
inner opening end on an inner-peripheral side of the rotor (121)
from its outer opening end near to an outer-peripheral side of the
rotor (121).
12. The compressor according to claim 11, wherein the first radial
passage (131a1) is tapered in a way that a diameter of the first
radial passage (131a1) becomes progressively smaller toward its
inner opening end on the inner-peripheral side of the rotor (121)
from its outer opening end near to the outer peripheral side of the
rotor (121).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a compressor for
compressing a medium of a compressed object, and particularly to a
compressor, installed in a refrigeration cycle for a vehicle
air-conditioning system or the like, for compressing a coolant
which circulates in the refrigeration cycle.
[0003] 2. Description of the Related Art
[0004] Compressors of a related technique each include an air
bleeding passage through which a crankcase and an intake chamber
communicate with each other. In general, lubricant oil is reserved
in the crankcase for the purpose of supplying the lubricant oil to
the sliding component parts in the crankcase. In the compressor
having the air bleeding passage, the lubricant oil reserved in the
crankcase flows out to the intake chamber through the air bleeding
passage, and accordingly causes two chief problems as follows.
First, once the lubricant oil flows out of the crankcase, not
enough lubricant oil is supplied to the sliding component parts in
the crankcase, and the shortage of the lubricant oil adversely
affects the sliding component parts. Second, once the lubricant oil
flows out of the crankcase, the lubricant oil circulates from the
crankcase, to the heat exchanger (such as the condenser and the
evaporator) in the refrigeration cycle through the intake chamber,
the cylinder bores, the exhaust chamber, and the outside of the
compressor. As a result, the lubricant oil adheres to the condenser
tubes in the heat exchanger, and decreases the heat exchange
efficiency of the heat exchanger. The above-mentioned related art
is disclosed in Japanese Patent Application, Laid-Open No. Sho.
62-203980 (Patent Document 1).
[0005] Thus, a compressor of another related technique has been
developed with these problems taken into consideration. In this
compressor, an air bleeding passage through which the crankcase and
the intake chamber always communicate with each other is provided
in the driving shaft with the inlet part of the air bleeding
passage being set in the radial direction of the driving shaft.
This related technique is disclosed in Japanese Patent Application,
Laid-Open No. 2003-343440 (Patent Document 2). Such a structure
causes a mist of oil included in the coolant fully contained in the
crankcase to collide against, and be captured by, the inner
peripheral surface of the inlet part of the air bleeding passage
with the rotation of the driving shaft when the mist of oil
attempts to flow into the air bleeding chamber, and to be pushed
back to the crankcase by centrifugal force generated by the
rotation of the driving shaft. Accordingly, this structure is
unlikely to allow the mist of oil included in the coolant fully
contained in the crankcase to flow out from the crankcase into the
intake chamber, and thus reduces the amount of oil flowing out of
the crankcase.
SUMMARY OF THE INVENTION
[0006] The present invention has been made with the foregoing
problem taken into consideration. An object of the present
invention is to provide a compressor capable of reducing the amount
of oil flowing out from an air bleeding passage to an intake
chamber.
[0007] For the purpose of achieving the object, a first aspect of
the present invention is a compressor including: a driving shaft
(10); a rotor (21, 121) fixed to the outer periphery of the driving
shaft (10) by press fitting; an intake chamber (7); a crankcase
(5); and an air bleeding passage (31) through which the intake
chamber (7) and the crankcase (5) communicate with each other, the
compressor in which the air bleeding passage (31) includes: a
radial passage (31b, 131b) which is formed in the driving shaft
(10) in a way that the radial passage (31b, 131b) is directed in a
radial direction of the driving shaft (10), and which communicates
with the intake chamber (7); and a radial passage (31a, 131a) which
is formed in the rotor (21, 121) in a way that the radial passage
(31a, 131a) is directed in the radial direction of the rotor (21,
121), and through which the radial passage (31b,131b) in the
driving shaft (10) and the crankcase (5) communicate with each
other, as well as the compressor in which an inlet part (61,161) of
the radial passage (31a,131a) in the rotor is configured as a
cylinder-shaped part (61,161) protruding from the outer periphery
of the rotor.
[0008] The first aspect causes a mist of oil to collide against,
and be captured by, the inner peripheral surface of the radial
passage in the rotor due to the rotational motion of the driving
shaft. In this respect, the mist of oil would otherwise flow into
the air bleeding passage from the crankcase along with a medium to
be compressed, and the radial passage works as the inlet part of
the air bleeding passage. Subsequently, the oil thus attached to
the radial passage in the rotor is pushed back to the crankcase by
centrifugal force generated by the rotation of the rotor. In this
manner, the first aspect offers a structure which unlikely allows
the lubricating oil in the crankcase to flow out to the intake
chamber through the air bleeding passage. With this simple
configuration, the first aspect makes it possible to reduce the
amount of oil flowing through the air bleeding passage.
[0009] In addition, because the inlet part of the radial passage in
the rotor is formed as the cylinder-shaped part protruding from the
outer peripheral surface of the rotor, this shape unlikely allows
the oil attached to the outer peripheral surface of the rotor to
flow into the air bleeding passage while climbing over steps formed
in the cylinder part.
[0010] A second aspect of the present invention, which is dependent
on the first aspect, is the compressor according to the first
aspect, in which the inlet part (61, 161) of the radial passage
(31a, 131a) in the rotor (21, 121) is provided in a location in
which the inlet part (61) does not to overlap a connecting
mechanism (40) in a circumferential direction of the rotor
(21,121). Here, the connecting mechanism (40) connects the rotor
(21, 121) with a swash plate (24) which is provided in the
crankcase (5).
[0011] The second aspect makes it possible to prevent the
cylinder-shaped part and the connecting mechanism from interfering
with each other when the rotor is molded, and from obstructing the
rotor 121 when the rotor 121 is removed from the mold. That is
because the inlet part of the radial passage in the rotor is formed
as the cylinder-shaped part, and because the inlet part is provided
in the way that the inlet part does not overlap the connecting
mechanism in the circumferential direction.
[0012] A third aspect of the present invention, which is dependent
on any one of the first and second aspects, is the compressor
according to any one of the first and second aspects, in which the
outer peripheral surface of the cylinder-shaped part (61) includes
an undercut part (61a) which gradually juts out from its base end
toward its front end.
[0013] The third aspect makes the oil attached to the outer
peripheral surface of the rotor harder to flow into the air
bleeding passage while climbing over the steps formed in the
cylinder-shaped part. That is because the outer peripheral surface
of the cylinder-shaped part includes the undercut part which
gradually juts out from its base end toward its front end.
[0014] A fourth aspect of the present invention, which is dependent
on any one of the first to third aspects, is the compressor
according to any one of the first to third aspects, in which the
passage cross-section area of the radial passage (31a, 131a) in the
rotor is smaller than that of the radial passage (31b, 131b) in the
driving shaft.
[0015] The fourth aspect increases the flow rate of the medium to
be compressed, which flows into the air bleeding passage, at the
inlet of the air bleeding passage. As a result, the fourth aspect
facilitates the separation of the mist of oil from the medium to be
compressed at the inlet of the air bleeding passage. That is
because the passage cross-section area of the radial passage in the
rotor is set smaller than that of the radial passage in the driving
shaft.
[0016] A fifth aspect of the present invention, which is dependent
on any one of the first to fourth aspects, is the compressor
according to any one of the first to fourth aspects, which further
includes a communicating part (135) through which the radial
passage (131a) in the rotor (121) and the radial passage (131b) in
the driving shaft (10) communicate with each other, and which is
formed in the outer peripheral surface of the driving shaft (10) or
the inner peripheral surface of the rotor (121).
[0017] The fifth aspect causes the mist of oil to collide against,
and attach to, the inner peripheral surface of the radial passage
in the rotor when the mist of oil flows into the air bleeding
passage from the crankcase along with the medium to be compressed,
as well as thereafter to be pushed back to the crankcase directly
by the centrifugal force. In this respect, even if the mist of oil
passes the radial passage in the rotor while not captured by the
inner peripheral surface of the radial passage in the rotor, the
mist of oil thereafter flows through the communicating part (135)
so that the mist of oil is further centrifuged in the communicating
part, instead of the mist of oil directly flowing into the radial
passage in the driving shaft after passing the radial passage in
the rotor. For this reason, the mist of oil is eventually pushed
back into the crankcase through the radial passages in the rotor.
As a result, the fifth aspect enhances the oil separating function
better than ever before.
[0018] In other words, the passage cross-section area of the radial
passage in the rotor is set smaller that that of the radial passage
in the driving shaft. This setting increases the flow rate of the
medium to be compressed, which flows into the air bleeding passage,
at the inlet of the air bleeding passage. The increased flow rate
makes it easy for the mist of oil flowing together with the medium
to be compressed to collide directly against the inner peripheral
surface of the radial passage or the inner peripheral surface of
the communicating part (135) due to its inertial force. This makes
it easier for the mist of oil to be separated from the medium to be
compressed.
[0019] A sixth aspect of the present invention, which is dependent
on any one of the first to fifth aspects, is the compressor
according to any one of the first to fifth aspects, in which the
radial passage (131a) in the rotor (121) is formed in a location
offset from the radial passage (131b) in the driving shaft (10) in
the rotational direction (R) of the rotor (121), thereby the radial
passage (131a) communicates with the radial passage (131b) through
the communicating passage (135).
[0020] A seventh aspect of the present invention, which is
dependent on any one of the first to sixth aspects, is the
compressor according to any one of the first to sixth aspects, in
which the radial passage (131a) in the rotor (121) is provided to
be offset from the radial passage (131b) in the driving shaft (10)
in a direction reverse to the rotational direction (R) of the
rotor.
[0021] Any one of the sixth and seventh aspects causes the mist of
oil included in the medium to be compressed flowing through the
communicating part to be subject to the centrifugal force for a
longer time, and accordingly increases the oil separating function
further. This effect is obtained by utilizing a phenomenon in which
the medium to be compressed flowing into the communicating part
from the radial passage in the rotor is not abreast of the rotation
of the rotor, so that the medium to be compressed flows in a
direction reverse to the rotational direction of the rotor.
Specifically, in the structure according to the invention of the
seventh aspect, the radial passage in the rotor is offset from the
radial passage in the driving shaft in the direction reverse to the
rotational direction of the rotor, and thus the medium to be
compressed flowing into the communicating part from the radial
passage in the rotor is not abreast of the rotation of the rotor so
that the medium to be compressed flows in the direction reverse to
the rotational direction of the rotor. As a result, the medium to
be compressed does not flow into the radial passage in the driving
shaft until the medium to be compressed makes at least
approximately one circuit along the communicating part. This causes
the mist of oil included in the medium to be compressed flowing
through the communicating part to be subject to the centrifugal
force for a longer time, and thus further increases the oil
separating function.
[0022] An eighth aspect of the present invention, which is
dependent on any one of the first to seventh aspects, is the
compressor according to any one of the first to seventh aspects, in
which the radial passage (131a) in the rotor (121) includes a first
radial passage (131a1) and the second radial passage (131a2) which
are arranged in the rotational direction (R) of the rotor.
[0023] In the structure according to the eighth aspect, multiple
radial passages are formed inside the rotor in the rotational
direction of the rotor. The structure having the multiple radial
passages which are formed inside the rotor brings about the oil
separating function as well as the structure having the single
radial passage which is formed inside the rotor.
[0024] A ninth aspect of the present invention, which is dependent
on any one of the first to eighth aspects, is the compressor
according to any one of the first to eighth aspects, in which the
passage cross-section area in the minimum-diameter portion of the
second radial passage (131a2) is formed smaller than the passage
cross-section area in the minimum-diameter portion of the first
radial passage (131a1).
[0025] A tenth aspect of the present invention, which is dependent
on any one of the first to ninth aspects, is the compressor
according to any one of the first to ninth aspects, in which the
first radial passage (131a1) is arranged in a location offset from
the radial passage (131b) in the driving shaft (10) in the
direction reverse to the rotational direction (R) of the rotor, and
in which the second radial passage (131a2) is arranged in a
location offset from the first radial passage (131a1) in the
rotational direction (R) of the rotor.
[0026] Any one of the ninth and tenth aspects facilitates the
medium to be compressed flowing through the first radial passage,
and on the contrary unlikely allows the medium to be compressed to
flow through the second radial passage. As a result, any one of the
ninth and tenth aspects causes the medium to be compressed to flow
into the communicating part chiefly through the first radial
passage 131a1. In addition, the medium to be compressed which flows
into the communicating part through the first radial passage is not
abreast of the rotation of the rotor, and thus flows in the
direction reverse to the rotational direction of the rotating
rotor. Only after making at least approximately one circuit along
the communicating part, the medium to be compressed is allowed to
flow into the radial passage in the driving shaft. At this time,
the mist of oil having flown into the communicating part through
the first radial passage together with the medium to be compressed
is centrifuged at the communication part. The mist of oil is
discharged to the crankcase through the second radial passage,
before making approximately one circuit along the communicating
part and then entering the radial passage in the driving shaft. For
this reason, any one of the ninth and tenth aspects reduces the
probability that the oil once centrifuged in the communicating part
may be drawn into the radial passage in the driving shaft under the
influence of the flow of the medium to be compressed, and
accordingly heightens the centrifugal separation function
further.
[0027] An eleventh aspect of the present invention, which is
dependent on any one of the first to tenth aspects, is the
compressor according to any one of the first to tenth aspects, in
which the second radial passage (131a2) is tapered in a way that
the diameter of the second radial passage (131a2) progressively
becomes larger toward its inner opening end on an inner-peripheral
side of the rotor from its outer opening end near to an
outer-peripheral side of the rotor.
[0028] The eleventh aspect makes it easy for the oil to be
discharged to the crankcase through the second radial passage more
smoothly. That is because the opening end of the second radial
passage in its inner periphery is set larger although the
minimum-diameter portion of the second radial passage is structured
small, or although the opening end of the second radial passage in
its outer periphery is structured small.
[0029] A twelfth aspect of the present invention, which is
dependent on any one of the first to eleventh aspects, is the
compressor according to any one of the first to eleventh aspects,
in which the first radial passage (131a1) is tapered in a way that
the diameter of the first radial passage (131a1) progressively
becomes smaller toward its inner opening end on the
inner-peripheral side of the rotor from its outer opening end near
to the outer-peripheral side of the rotor.
[0030] The twelfth aspect makes the medium to be compressed easy to
flow through the first radial passage, and on the contrary unlikely
allows the medium to be compressed to flow through the second
radial passage. As a result, the twelfth aspect causes the medium
to be compressed to flow into the communicating part chiefly
through the first radial passage (131a1). In addition, the medium
to be compressed which flows through the first radial passage is
not abreast of the rotation of the rotor, and thus flows in the
direction reverse to the rotational direction of the rotating
rotor. Only after making at least approximately one circuit along
the communicating part, the medium to be compressed is allowed to
flow into the radial passage in the driving shaft. At this time,
the mist of oil having flown into the communicating part through
the first radial passage together with the medium to be compressed
is designed to be centrifuged. The mist of oil is discharged to the
crankcase through the second radial passage, before making
approximately one circuit along the communicating part and then
entering the radial passage in the driving shaft. For this reason,
the twelfth aspect reduces the probability that the oil once
centrifuged in the communicating part may be drawn into the radial
passage in the driving shaft under the influence of the flow of the
medium to be compressed, and accordingly heightens the centrifugal
separation function further. In addition, because the second radial
passage is tapered in the way that the opening end in the inner
peripheral side of the second radial passage is set larger, the
twelfth aspect makes it possible to discharge the oil to the
crankcase through the second radial passage more smoothly.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0031] FIG. 1 is a cross-sectional view of a compressor according
to a first embodiment of the present invention.
[0032] FIG. 2 is a magnified, cross-sectional view showing an inlet
part of an air bleeding passage in the compressor in a magnified
manner according to a first embodiment of the present
invention.
[0033] FIG. 3 is a magnified, cross-sectional view showing an inlet
part of an air bleeding passage in a compressor in a magnified
manner according to a second embodiment of the present
invention.
[0034] FIG. 4 is a side view which is viewed in the IV-IV direction
indicated by an arrow in FIG. 3.
[0035] FIG. 5 is a perspective view schematically showing a rotor
in a compressor according to a third embodiment of the present
invention.
[0036] FIG. 6 is a cross-sectional view of a compressor according
to a fourth embodiment of the present invention.
[0037] FIG. 7 is a magnified, cross-sectional view of showing an
inlet part of an air bleeding passage in the compressor in a
magnified manner according to the fourth embodiment of the present
invention.
[0038] FIG. 8 is a cross-sectional view taken along the VIII-VIII
line of FIG. 7.
[0039] FIG. 9 is a schematic perspective view showing a
modification of a rotor in the compressor according to the fourth
embodiment of the present invention.
[0040] FIG. 10 is a cross-sectional view of a compressor according
to a fifth embodiment of the present invention.
[0041] FIG. 11 is a cross-sectional view of a rotor in the
compressor according to the fifth embodiment of the present
invention, and is the cross-sectional view corresponding to FIG.
8.
[0042] FIG. 12 is a cross-sectional view of a rotor in a compressor
according to a 6th embodiment of the present invention, and is the
cross-sectional view corresponding to FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] Descriptions will be provided hereinbelow for the
embodiments of the present invention by referring to the
drawings.
First Embodiment
[0044] FIGS. 1 and 2 each show a compressor according to a first
embodiment. FIG. 1 is a cross-sectional view of the compressor, and
FIG. 2 is a magnified cross-sectional view showing an inlet side of
an air bleeding passage in the compressor shown in FIG. 1.
[0045] As shown in FIG. 1, the compressor according to the present
embodiment is a swash plate (a cam plate) variable displacement
compressor, and is set in a refrigeration cycle for an air
conditioning system for a vehicle, which is mounted on the vehicle
such as an automobile.
[0046] This swash plate variable displacement compressor includes:
a cylinder block 2 including multiple cylinder bores 3; a front
head 4 connected to the front end surface of the cylinder block 2,
a crankcase 5 being formed between the front head 4 and the
cylinder block 2; a rear head 6 connected to the rear end surface
of the cylinder block 2 with a valve plate 9 being interposed in
between, an intake chamber 7 and an exhaust chamber 8 being formed
in the rear head 6.
[0047] The cylinder block 2, the front head 4 and the rear head 6
are fixedly fastened one to another by use of through-bolts, and
thus form a housing 1 for the compressor.
[0048] The valve plate 9 includes: intake holes 11 respectively for
causing the cylinder bores 3 to communicate with the intake
chambers 7; and exhaust holes 12 respectively for causing the
cylinder bores 3 to communicate with the exhaust chambers 8.
[0049] Reed intake valves (not illustrated) for opening and closing
the respective intake holes 11 are provided to the cylinder block 2
side of the valve plate 9. On the other hand, reed exhaust valves
(not illustrated) and the retainers 15 are provided to the rear
head 6 side of the valve plate 9. The reed exhaust valves open and
close the exhaust holes 12. The retainers 15 retain the respective
exhaust valves, and respectively restrict the opening limits of the
exhaust valves.
[0050] A shaft supporting holes 19 and 20 are provided in the
center portions of the cylinder block 2 and the front head 4,
respectively. The shaft supporting holes 19 and 20 rotatably
support a driving shaft 10 with bearings 17, 37, and 18 being
interposed in between.
[0051] A rotor 21, a sleeve 22 and a swash plate 24 are provided
inside the crankcase 5. The rotor 21 is fixed to the driving shaft
10 by press-fitting from the outer periphery of the driving shaft
10. The driving shaft 10 is slidably fitted into the sleeve 22. The
swash plate 24 is tiltably put on the sleeve 22. The swash plate 24
is configured including a journal 25 and a swash plate main body
26. The journal 25 is directly put on the sleeve 22, and is almost
shaped like a cylinder. The swash plate main body 26 is fixed to
the journal 25, and is shaped like a disc. In addition, the rotor
21 is configured including: a cylinder-shaped hub part 21a into
which the driving shaft 10 is press-fitted; and a disc part 21b
protruding from the hub part 21a in an outer diameter
direction.
[0052] The rotor 21 and the swash plate 24 are connected to each
other by use of a connecting mechanism 40. This connecting
mechanism 40 causes the rotor 21 and the swash plate 24 to
integrally rotate by transmitting the rotation of the rotor 21 to
the swash plate 24 while allowing the swash plate 24 to incline.
Incidentally, the connecting mechanism 40 according to the present
embodiment is configured including: a hinge arm 21h protruding from
the rotor 21 toward the swash plate 24; a hinge arm 24h protruding
from the swash plate 24 toward the rotor 21; and a link 27 for
connecting the hinge arms 21h and 24h to each other by use of pins
28 and 28.
[0053] Pistons 29 housed in the respective cylinder bores 3 are
connected to the swash plate main body 26 with being sandwiched by
paired shoes 30. When the swash plate main body 26 rotates, the
pistons 29 reciprocate back and forth in the respective cylinder
bores 3.
[0054] The basic function of the compressor is as follows.
Depending on the reciprocation of these pistons 29, a coolant as a
medium to be compressed is aspirated from the intake chamber 7, the
intake holes 11 in the valve plate 9 to the inside of cylinder
bores 3. The coolant is compressed in the cylinder bores 3.
Thereafter, the coolant thus compressed is exhausted from the
cylinder bores 3, the exhaust holes 12 in the valve plate 9 to the
exhaust chamber 8.
[0055] The compressor 1 according to the present embodiment
includes a pressure control system for the purpose of making the
exhaust displacement of the compressor variable. The pressure
control system is configured including: an air bleeding passage 31
(indicated by an arrow in FIG. 1) through which the crankcase 5 and
the intake chamber 7 always communicate with each other; a air
supply passage 32 (indicated by an arrow in FIG. 1) through which
the crankcase 5 and the exhaust chamber 8 communicate with each
other; and a control valve 33 for opening and closing the air
supply passage 32. The air bleeding passage 31 makes a coolant gas
in the crankcase 5 return to the intake chamber 7 depending on the
pressure of the coolant gas in the crankcase 5. Through the air
supply passage 32, the coolant gas is forcedly introduced from the
exhaust chamber 8 to the crankcase 5. When the air supply passage
32 is opened or closed by the control valve 33, the amount of the
coolant gas flowing from the exhaust chamber 8 to the crankcase 5
is controlled, and the pressure in the crankcase 5 is thus
controlled. Thereby, the inclination angle of the swash plate 24 is
changed, that is to say, the piston strokes are changed. This
changes the exhaust displacement of the compressor.
[0056] Next, detailed descriptions will be provided for the
structure of the air bleeding passage.
[0057] The air bleeding passage 31 includes: a radial passage 31a;
a radial passage 31b; an axial passage 31c; a rear end part 31d; a
groove part 31e; a hole part 31f; and a hole part 31g (see FIG. 1).
The radial passage 31a is formed penetrating the rotor 21 with its
end open to the crankcase 5, and extends in a radial direction of
the rotor 21. The radial passage 31b is provided in the driving
shaft 10, and is directed in a radial direction of the driving
shaft 10 to directly communicate with the radial passage 31 in the
rotor 21. The axial passage 31c is provided in the driving shaft 10
in the axial direction of the driving shaft 10 to directly
communicate with the radial passage 31b in the driving shaft 10.
The rear end part 31d of the shaft supporting hole 19 communicates
with the axial passage 31c in the driving shaft 10. The groove part
31e is provided in the rear end surface of the cylinder block 2 to
communicate with the rear end part 31d of the shaft supporting hole
19. The hole part 31f is formed penetrating the valve plate 9 to
communicate with the groove part 31e in the cylinder block 2. The
hole part 31g is provided to the rear head 6 to allow the hole part
31f in the valve plate 9 and the intake chamber 7 to communicate
with each other therethrough.
[0058] An inlet part 61 of the radial passage 31a in the rotor 21
is formed as a cylinder-shape part 61 protruding from the outer
peripheral surface of the rotor 21.
[0059] Next, descriptions will be provided for how the compressor
according to the present embodiment operates.
[0060] Once the driving shaft 10 rotates, the rotor 21 rotates
integrally with the driving shaft 10. This rotation of the rotor 21
is transmitted to the swash plate 24 through the connecting
mechanism 40. The rotation of the swash plate 24 is converted to
the reciprocations of the respective pistons 29 through the paired
piston shoes 30 and 30. Thereby, the pistons 29 reciprocate back
and forth in the respective cylinder bores 3. Depending on the
reciprocations of the respective pistons 29, the coolant in the
intake chamber 7 is aspirated into the cylinder bores 3 through the
intake holes 11 in the valve plate 9. Thereafter, the coolant is
compressed in each of the cylinder bores 3. The coolant thus
compressed is exhausted to the exhaust chamber 8 through the
exhaust holes 12 in the valve plate 9.
[0061] When the volume of exhausted coolant is intended to be
changed, the control valve 33 is opened or closed. Thereby, the
pressure in the crankcase 5 is controlled, and the balance between
pressures respectively in front and rear of each piston is
controlled. These controls change the strokes of the respective
pistons. More specifically, once the air supply passage 32 is
opened by the valve 33, the high-pressure coolant gas flows into
the crankcase 5 from the exhaust chamber 8 through the air supply
passage 32. Thereby, the pressure in the crankcase 5 rises. Once
the pressure in the crankcase 5 rises, the swash plate 24 moves
closer to the cylinder block 2 with the inclination angle of the
swash plate 24 being decreased. This reduces the strokes of the
respective pistons, and accordingly decreases the volume of
exhausted coolant. On the other, once the air supply passage 32 is
closed by the control valve 33, the difference between the pressure
in the intake chamber 7 and the pressure in the crankcase 5
decreases to zero, and the pressure in the intake chamber 7 becomes
equal to the pressure in the crankcase 5. That is because the
coolant gas in the crankcase 5 is constantly released to the intake
chamber 7 through the air bleeding passage 31. In response, the
swash plate 24 moves in a direction in which the swash plate 24
goes away from the cylinder block 2 while increasing the
inclination angle of the swash plate 24. This movement increases
the strokes of the respective pistons, and thus increases the
volume of exhausted coolant.
[0062] Lubricant oil is reserved in the crankcase 5 for the purpose
of lubricating the sliding component parts in the crankcase 5. The
oil is swashed up into a mist by rotary component parts including
the rotor 21 and the swash plate 24, and the crankcase 5 is filled
with the mist of oil. Thereby, the mist of oil is supplied to the
sliding surfaces of the sliding component parts in the crankcase 5.
It is likely that this mist of oil may flow out to the intake
chamber 7 through the air bleeding passage 31 along with the
coolant gas in the crankcase 5. However, the present embodiment
decreases the amount of oil flowing out of the crankcase 5 by use
of the following scheme.
[0063] In the compressor according to the present embodiment,
because the radial passage 31a in the rotor 21 which works as the
inlet of the air bleeding passage 31 extends in the radial
direction of the rotor 21, the mist of oil which attempts to flow
into the air bleeding passage 31 from the crankcase 5 along with
the coolant gas collides against, and is captured by, the inner
peripheral surface of the radial passage 31a in the rotor 21 due to
the rotary motion of the driving shaft 10. Subsequently, the oil
thus attached to the radial passage 31a in the rotor 21 is pushed
back to the crankcase 5 due to centrifugal force generated by the
rotation of the rotor 21. In this manner, the compressor according
to the present embodiment has a structure which unlikely allows the
lubricating oil to flow out to the intake chamber 7 from the
crankcase 5. With this simple configuration, the compressor
according to the present embodiment is capable of reducing the
amount of oil flowing through the air bleeding passage 31.
[0064] Furthermore, in the present embodiment, because the inlet
part 61 of the radial passage 31a in the rotor 21 is formed as the
cylinder-shaped part 61 protruding from the outer peripheral
surface of the rotor 21, this shape unlikely allows the oil
attached to the outer peripheral surface of the rotor 21 to flow
into the air bleeding passage 31 while climbing over steps formed
in the cylinder-shape part 61.
[0065] The cylinder-shaped part 61 is provided in a location in
which the cylinder-shaped part 61 does not overlap the hinge arm
21h of the rotor 21, which constitutes the connecting mechanism 40,
in the circumferential direction of the rotor 21. This makes it
possible to prevent the cylinder-shaped part 61 and the hinge arm
21h from interfering with each other when the rotor 21 is molded
and from obstructing the rotor 121 when the rotor 121 is removed
from the mold.
[0066] Hereinbelow, the effects (results) of the present embodiment
will be summarized.
(1) The compressor according to the present embodiment includes:
the housing 1 including the crankcase 5, the intake chamber 7, the
exhaust chamber 8 and the cylinder bores 3 in its inside; the
driving shaft 10 which is pivotally supported by the housing 1
rotatably, and which rotationally drives in the crankcase 5; the
rotor 21 fixed to the driving shaft 10; the swash plate 24 tiltably
put on the driving shaft 10; the connecting mechanism 40 which
connects the rotor 21 and the swash plate 24 to each other, and
which causes the swash plate 24 to rotate together with the rotor
21 while allowing the inclination angle of the swash plate 24 to be
changed; the pistons 29 which reciprocate back and forth in the
respective cylinder bores 3 in response to the rotation of the
swash plate 24, and which makes the coolant as the medium to be
compressed to be aspirated, compressed and exhausted, through their
respective reciprocations; and the air bleeding chamber 31 through
which the intake chamber 7 and the crankcase 5 communicate with
each other. In addition, the air bleeding passage 31 is configured
including at least: the radial passage 31b which is formed in the
driving shaft 10 in the way that the radial passage 31b is directed
in the radial direction of the driving shaft 10, and which
communicates with the intake chamber 7; and the radial passage 31a
which is formed in the rotor 21 in the way that the radial passage
31a is directed in the radial direction of the rotor 21, and
through which the radial passage 31b in the driving shaft 10 and
the crankcase 5 are communicatively connected to each other. The
inlet part 61 of the radial passage 31a in the rotor 21 is
configured as the cylinder-shaped part 61 protruding from a part 63
of the outer periphery (or the outer peripheral surface 63 of the
hub part 21a of the rotor 21 in this example), and is provided in
the location which causes the inlet part 61 not to overlap the
connecting mechanism 40 in the circumferential direction.
[0067] For this reason, in the compressor according to the present
embodiment, the mist of oil which attempts to flow from the
crankcase 5 into the air bleeding passage 31 together with the
coolant gas collides against, and is captured by, the inner
peripheral surface of the radial passages 31a and 31b as the inlet
part of the air bleeding passage 31 in response to the rotary
motion of the driving shaft 10. Subsequently, the oil separated
from the gas in the radial passages 31a and 31b is pushed back to
the crankcase 5 due to the centrifugal force generated by the
rotation of the rotor. This offers the structure in which, although
the air bleeding passage 31 let the crankcase 5 and the intake
chamber 7 constantly communicate with each other, the air bleeding
passage 31 actively makes the oil separate from the gas (or the
liquid from the gas) at the its inlet parts 31a and 31b by use of
the rotary motion of the driving shaft 10. As a result, with its
simple configuration, the present embodiment is capable of reducing
the amount of oil flowing out of the crankcase.
[0068] Furthermore, the present embodiment has an effect of
enabling the sliding component parts in the crankcase 5 to be
supplied with oil which is scattered in the crankcase 5, through an
end of the inlet of the radial passage 31a.
[0069] Moreover, the present embodiment unlikely allows the oil
attached to the outer peripheral surface of the rotor 21 to flow
into the air bleeding passage 31 while climbing over the steps
formed in the cylinder-shaped part 61. That is because the inlet
part 61 of the radial passage 31a in the rotor 21 is formed as the
cylinder-shaped part 61 protruding from the outer peripheral
surface of the rotor 21. In addition, the present embodiment
heightens the centrifugal separation effect further. That is
because the radial passages 31a and 31b working because the inlet
part of the air bleeding passage 31 are longer by the protrusion
amount d with which the cylinder-shaped part 61 protrudes from the
outer peripheral surface of the rotor 21.
[0070] Furthermore, the present embodiment makes it possible to
prevent the cylinder-shaped part 61 and the hinge arm 21 from
interfering with each other when the rotor 21 is molded, and from
obstructing the rotor 121 when the rotor 121 is removed from the
mold. That is because the inlet part 61 of the radial passage 31a
in the rotor 21 is formed as the cylinder-shaped part 61, and
concurrently because the cylinder-shaped part 61 is provided in the
location which does not cause the cylinder-shaped part 61 to
overlap the hinge arm 21h of the rotor 21 which constitutes the
connecting mechanism 40, in the circumferential direction.
[0071] The present embodiment has an effect of enabling the inlet
part of the radial passage in the rotor to be formed as the
cylinder-shaped part with a smaller number of parts than a
structural design in which a cylinder-shaped member discrete from a
member constituting the rotor is set in the rotor. Accordingly, the
present embodiment has an effect of saving the manufacturing
costs.
(2) The present embodiment increases the flow rate of the coolant
flowing into the air bleeding passage 31 in the inlet 31a of the
air bleeding passage, and accordingly facilitates the separation of
the mist of oil from the coolant in the inlet 31a of the air
bleeding passage. That is because, in the compressor according to
the present embodiment, the passage cross-section area of the
radial passage 31a in the rotor is set smaller than the passage
cross-section area of the radial passage 31b in the driving
shaft.
[0072] Next, descriptions will be provided for the other
embodiments. In the following descriptions, components which are
the same as those according to the foregoing embodiment will be
denoted by the same reference numerals, and duplicated descriptions
will be omitted.
Second Embodiment
[0073] FIGS. 3 and 4 each show a second embodiment of the present
invention.
[0074] The shape of outer peripheral surface of the cylinder-shaped
part 61 in the compressor according to the second embodiment, which
is shown in FIGS. 3 and 4, is different from the shape of outer
peripheral surface of the cylinder-shaped part 61 in the compressor
according to the first embodiment. Specifically, in the compressor
according to the second embodiment, the outer peripheral surface of
the cylinder-shaped part 61 includes an undercut part 61a which
gradually juts out from its base end toward its front end. This
configuration makes it harder for the oil attached to the outer
peripheral surface 63 of the hub part 21a in the rotor 21 to climb
over the steps formed in the cylinder-shaped part 61. This makes it
harder for the oil to flow into the air bleeding passage 31.
Third Embodiment
[0075] FIG. 5 shows a third embodiment of the present
invention.
[0076] In the compressor according to the third embodiment, which
is shown in FIG. 5, the orientation of the cylinder-shaped part 61
is different from the orientation of the hinge arm 21h by
90.degree. in the circumferential direction of the rotor. In the
compressors according to the first and second embodiments, the
orientation of the cylinder-shaped part 61 is different from the
orientation of the hinge arm 21h by 180.degree. in the
circumferential direction of the rotor. The third embodiment is
different from the first and second embodiments in this manner.
However, the third embodiment brings about the same working effect
as the first and second embodiments do.
(Modification)
[0077] In the foregoing embodiments, the single radial passage 31a
is provided as the inlet part of the air bleeding passage 31. In
the present invention, as the inlet part of the air bleeding
passage 31, multiple radial passages 31a may be provided arranged
in the axial direction of the driving shaft. Otherwise, multiple
radial passages 31a may be provided arranged in the circumferential
direction of the rotor.
[0078] In the foregoing embodiments, the axial passage 31c in the
driving shaft 10 is provided along the center line of the driving
shaft 10. In the present invention, however, the axial passage 31c
in the driving shaft 10 may be eccentric to the center line of the
driving shaft 10, or may slant to the center line of the driving
shaft 10, as long as the centrifugal separation effect is
exerted.
[0079] In the foregoing embodiments, the radial passage 31b in the
driving shaft 10 and the radial passage 31a in the rotor 21 are
orthogonal to the axial passage 31c in the driving shaft 10. In the
present invention, however, these radial passages 31b and 31a may
slant to the axial passage 31c in the driving shaft 10 as long as
the centrifugal separation effect is exerted.
[0080] The compressors according to the foregoing embodiments are
the swash variable displacement compressors in which the swash
plate main body 26 is fixed to the journal 25 so that the swash
plate main body 26 rotates integrally with the driving shaft 10.
However, the present invention is also applicable to a wobble
variable displacement compressor in which the swash plate main body
26 is rotatably put on the journal 25 so that the swash plate main
body 26 rotates unintegrally with the driving shaft 10. The present
invention is also applicable to variable displacement compressors
of any other types. It goes without saying that the present
invention is applicable to not only variable displacement
compressors but also fixed displacement compressors.
Fourth Embodiment
[0081] Next, descriptions will be provided for a further modified
structure of the air bleeding passage 31 as a fourth
embodiment.
[0082] As shown in FIG. 6, an air bleeding passage 31 is configured
with a communicative sequence in which a radial passage 131a
communicates with a communicating part 135, which communicates with
a radial passage 131b, which communicate with an axial passage 31c,
which communicates with a rear end part 31d, which communicates
with a groove part 31e, which communicates with a hole part 31f,
which communicates with a hole part 31g. The radial passage 131a is
formed in a rotor 121. The communicating part 135 is provided
between a press-fitting surface 165 of the rotor 121 and a
press-fitting surface 167 of the driving shaft 10 (see FIGS. 7 and
8). The radial passage 131b is formed in the driving shaft 10. The
axial passage 31c is formed in the driving shaft 10. The rear end
part 31d is a part of a shaft supporting hole 19. A groove part 31e
is provided in the rear end surface of the cylinder block 2. The
hole part 31f is formed penetrating a valve plate 9. The hole part
31g is provided in the rear head 6.
[0083] As shown in FIGS. 7 and 8, the radial passage 131a in rotor
121 is formed penetrating a hub part 121a of the rotor 121 in the
radial direction of the rotor. The radial passage 131b in the
driving shaft 10 is similarly formed penetrating the driving shaft
10 in the radial direction of the driving shaft 10. The radial
passage 131b in the driving shaft 10 and the radial passage 131a in
the rotor 121 are provided in the respective locations which are
offset (shifted) from each other in the circumferential direction.
The radial passage 131b and the radial passage 131a are
communicatively connected to each other through the communicating
part 135. As an annular groove extending in the circumferential
direction, the communicating part 135 is constructed in an inner
peripheral surface 165 of the hub part 121a of the rotor 121. A
cylinder-shaped part (or an inlet part) 161 of the radial passage
131a in the rotor 121 is formed as a cylinder-shaped part 161
protruding an outer peripheral surface 163 of the hub part 121a of
the rotor 121.
[0084] Next, descriptions will be provided for effects of the
compressor according to the present embodiment.
[0085] Once the driving shaft 10 rotates, the rotor 121 rotates
integrally with the driving shaft 10. This rotation of the rotor
121 is transmitted to the swash plate 24 through the connecting
mechanism 40. The rotation of the swash plate 24 is converted to
the reciprocation of the pistons 29 through the paired piston shoes
30 and 30. Thereby, the pistons 29 reciprocate back and forth in
the respective cylinder bores 3. Depending on the reciprocation of
the pistons 29, the coolant in the intake chamber 7 is aspirated
into the cylinder bores 3 through the intake holes 11 in the valve
plate 9. Thereafter, the coolant thus aspirated is compressed in
each cylinder bore 3. Subsequently, the compressed coolant is
exhausted to the exhaust chamber 8 through the corresponding
exhaust hole 12 in the valve plate 9.
[0086] When the volume of exhausted coolant is intended to be
changed, the control valve 33 is opened or closed. Thereby, the
pressure in the crankcase 5 is controlled, and the balance between
pressures respectively in front and rear of each piston is
controlled. These controls change the strokes of the respective
pistons. More specifically, once the air supply passage 32 is
opened by the valve 33, the high-pressure coolant gas flows into
the crankcase 5 from the exhaust chamber 8 through the air supply
passage 32. Thereby, the pressure in the crankcase 5 rises. Once
the pressure in the crankcase 5 rises, the swash plate 24 moves
closer to the cylinder block 2 with the inclination angle of the
swash plate 24 being decreased. This reduces the strokes of the
respective pistons, and accordingly decreases the volume of
exhausted coolant. On the other hand, once the air supply passage
32 is closed by the control valve 33, the difference between the
pressure in the intake chamber 7 and the pressure in the crankcase
5 reduces to zero, and the pressure in the intake chamber 7 becomes
equal to the pressure in the crankcase 5. That is because the
coolant gas in the crankcase 5 is constantly released to the intake
chamber 7 through the air bleeding passage 31. In response, the
swash plate 24 moves in a direction in which the swash plate 24
goes away from the cylinder block 2 while increasing the
inclination angle of the swash plate 24. This movement increases
the strokes of the respective pistons, and thus increases the
volume of exhausted coolant.
[0087] Lubricant oil is reserved in the crankcase 5 for the purpose
of lubricating the sliding component parts in the crankcase 5. The
oil is swashed up into a mist by rotary component parts including
the rotor 121 and the swash plate 24, and the crankcase 5 is filled
with the mist of oil. Thereby, the mist of oil is supplied to the
sliding component parts in the crankcase 5.
[0088] It is likely that this mist of oil may flow out to the
intake chamber 7 through the air bleeding passage 31 together with
the coolant gas in the crankcase 5. However, the present embodiment
decreases the amount of oil flowing out of the crankcase 5 by use
of the following scheme.
[0089] In the present embodiment, because the radial passage 131a
in the rotor 121 which works as the inlet of the air bleeding
passage 31 extends in the radial direction of the rotor 21, the
mist of oil which attempts to flow into the air bleeding passage 31
from the crankcase 5 together with the coolant gas collides
against, and is captured by, the inner peripheral surface of the
radial passage 131a in the rotor 121 due to the rotary motion of
the driving shaft 10. Subsequently, the oil thus attached to the
radial passage 131a in the rotor 121 is pushed back to the
crankcase 5 due to centrifugal force generated by the rotation of
the rotor 121. In this manner, the compressor according to the
present embodiment has a structure which unlikely allows the
lubricating oil to flow out to the intake chamber 7 from the
crankcase 5 through the air bleeding passage 31. With this
configuration, the present embodiment reduces the amount of oil
flowing through the air bleeding passage 31.
[0090] In this respect, even if the mist of oil does not collide
against, or is not captured by, the inner peripheral surface of the
radial passage 131a in the rotor 121 so that the mist of oil passes
the radial passage 131a in the rotor 121, the mist of oil
subsequently flows in the communicating part 135 instead of
directly flowing into the radial passage 131b in the driving shaft
10. For this reason, the mist of oil is centrifuged in this
communicating part 135, and the oil thus centrifuged is pushed
against the outer peripheral surface of the communicating part 135.
Eventually, the oil is pushed out into the crankcase 5 through the
radial passage 131a in the rotor 121. Consequently, the present
embodiment offers the structure which has the heightened oil
separating function, and which unlikely allows the lubricant oil to
flow out of the crankcase 5 to the intake chamber 7, through
centrifugal separation not only in the radial passage 131a in the
rotor 121 but also in the communicating part 135.
[0091] Furthermore, in the present embodiment, the cylinder-shaped
part (or the inlet part) 161 of the radial passage 131a in the
rotor 121 is formed as the cylinder-shaped part 161 protruding from
the outer peripheral surface of the rotor 121. This shape unlikely
allows the oil attached to the outer peripheral surface of the
rotor 121 to flow into the air bleeding passage 31 while climbing
over steps formed in the cylinder-shape part 161.
[0092] The effects (results) of the present embodiment will be
summarized as follows.
(1) The compressor according to the present embodiment includes:
the housing 101 including the crankcase 5, the intake chamber 7,
the exhaust chamber 8 and the cylinder bores 3 in its inside; the
driving shaft 10 which is pivotally supported by the housing 101
rotatably, and which rotationally drives in the crankcase 5; the
rotor 121 fixed to the driving shaft 10; the swash plate 24
tiltably put on the driving shaft 10; the connecting mechanism 40
which connects the rotor 121 and the swash plate 24 to each other,
and which causes the swash plate 24 to rotate together with the
rotor 121 while allowing the inclination angle of the swash plate
24 to be changed; the pistons 29 which reciprocate back and forth
in the respective cylinder bores 3 in response to the rotation of
the swash plate 24, and which aspirate, compress and exhaust the
coolant as the medium to be compressed through their respective
reciprocations; and the air bleeding chamber 31 through which the
intake chamber 7 and the crankcase 5 communicate with each other.
In addition, the air bleeding passage 31 is configured including at
least: the radial passage 131b which is formed in the driving shaft
10 in the way that the radial passage 131b is directed in the
radial direction of the driving shaft 10, and which indirectly
communicates with the intake chamber 7; and the radial passage 131a
which is formed in the rotor 121 in the way that the radial passage
131a is directed in the radial direction of the rotor 121, and
which directly communicates with the crankcase 5. In addition, the
radial passage 131a in the rotor 121 and the radial passage 131b in
the driving shaft 10 are arranged to be offset (shifted) from each
other so as not to be arranged in a line. Moreover, the
communicating part 135 through which the radial passage 131a in the
rotor 121 and the radial passage 131b in the driving shaft 10
communicate with each other is formed in the inner peripheral
surface of the rotor 121.
[0093] For this reason, the mist of oil which attempts to flow from
the crankcase 5 into the air bleeding passage 31 together with the
coolant gas collides against, and attaches to, the inner peripheral
surface of the radial passages 131a in the rotor 121. The oil thus
attached thereto is pushed out into the crankcase 5 by centrifugal
force. In this respect, even if the mist of oil is not captured by
the inner peripheral surface of the radial passage 131a in the
rotor 121 so that the mist of oil passes the radial passage 131a in
the rotor 121, the oil is subsequently further centrifuged in the
communicating part 135 instead of directly flowing into the radial
passage 131b in the driving shaft 10. Eventually, the oil is pushed
out into the crankcase 5 through the radial passage 131a in the
rotor 121. For this reason, the present embodiment enhances the oil
separating function better than ever.
(2) In the compressor according to the present embodiment, the
passage cross-section area of the radial passage 131a in the rotor
121 is set smaller that that of the radial passage 131b in the
driving shaft 10. This setting increases the flow rate of the
coolant gas, which flows into the air bleeding passage 31, at the
inlet of the air bleeding passage 31. The increased flow rate makes
it easy for the mist of oil flowing together with the coolant gas
to collide directly against the inner peripheral surface of the
radial passage 131a or the inner peripheral surface of the
communicating part 135 due to its inertial force. This makes it
easier for the mist of oil to be separated from the medium of the
coolant gas. (3) The present embodiment unlikely allows the oil
attached to the outer peripheral surface of the rotor 121 to flow
into the air bleeding passage 31 while climbing over the steps
formed in the cylinder-shaped part 161. That is because the
cylinder-shaped part (or the inlet part) 161 of the radial passage
131a in the rotor 121 is formed as the cylinder-shaped part 161
protruding from the part 163 on the outer peripheral surface side
of the rotor 121 (the outer-peripheral surface 163 of the hub part
121a of the rotor 121 in this example). In addition, the present
embodiment heightens the centrifugal separation effect further.
That is because the radial passages 131a and 131b working as the
inlet part of the air bleeding passage 31 are longer by the
protrusion amount d with which the cylinder-shaped part 161
protrudes from the outer peripheral surface of the rotor 121.
[0094] The present embodiment has an effect of enabling the inlet
part (or the cylinder-shaped part) 161 of the radial passage 131a
in the rotor 121 to be formed as the cylinder-shaped part 161 with
a smaller number of parts than a structural design in which a
cylinder-shaped member discrete from a member constituting the
rotor is set in the rotor. Accordingly, the present embodiment has
an effect of saving the manufacturing costs.
(4) Like in the modification of the fourth embodiment, which is
shown in FIG. 9, the cylinder-shaped part 161 may be provided in a
location in which the cylinder-shaped part 161 does not overlap the
hinge arm 121h of the rotor 121 which constitutes the connecting
mechanism 40 in the circumferential direction of the rotor 121. In
this case, the present embodiment makes it possible to prevent the
cylinder-shaped part 161 and the hinge arm 121h from interfering
with each other when the rotor 121 is molded, and from obstructing
the rotor 121 when the rotor 121 is removed from a mold.
Fifth Embodiment
[0095] Next, descriptions will be provided for the other
embodiments. FIGS. 10 and 11 each show a compressor according to a
fifth embodiment of the present invention. A further modification
is introduced to the passage configuration of the air bleeding
passage 31 inside a housing 201. The illustration of the
cylinder-shaped part 161 shown in FIG. 10 is omitted from FIG.
11.
[0096] The location of the radial passage 131a in the rotor 121 in
the compressor according to the fifth embodiment is different from
the location the radial passage 131a in the rotor 121 in the
compressor according to the fourth direction. Specifically, in the
fourth embodiment, the location of the radial passage 131a in the
rotor 121 is 180.degree. opposite to the location of the radial
passage 131b in the driving shaft 10. In the fifth embodiment, the
radial passage 131a in the rotor 121 is placed in a location close
to the radial passage 131b in the driving shaft 10 and offset
(shifted) from the radial passage 131b in a direction reverse to
the rotational direction R of the rotor 121.
[0097] With this configuration, the fifth embodiment causes the
mist of oil included in the coolant gas flowing in the
communicating part 135 to be subject to the centrifugal force for a
longer time, and heightens the oil separating function further.
[0098] This effect is obtained by utilizing a phenomenon in which
the coolant gas flowing into the communicating part 135 from the
radial passage 131a in the rotor 121 is not abreast with the
rotation of the rotor 121 so that the coolant gas flows in a
direction reverse to the rotational direction R of the rotating
rotor 121. Specifically, in the structure in which the radial
passage 131a in the rotor 121 is offset (shifted) from the radial
passage 131b in the driving shaft 10 in the direction reverse to
the rotational direction R of the rotor 121, the coolant gas having
flown into the communicating part 135 from the radial passage 131a
in the rotor 121 flows in the direction reverse to the rotational
direction R of the rotating rotor. As a result, the coolant gas
does not flow into the radial passage 131b in the driving shaft 10
until the coolant gas makes at least approximately one circuit
along the communicating part 135. This causes the mist of oil
included in the coolant gas to be subject to centrifugal force for
a longer time, and thus heightens the oil separating function
further. It should be noted that the foregoing effect remains the
same, no matter whether the cylinder-shaped part 161 whose
illustration is omitted from FIG. 11, and which is shown in FIG.
10, is present or absent.
Sixth Embodiment
[0099] FIG. 12 shows a sixth embodiment of the present
invention.
[0100] A compressor according to the sixth embodiment is different
from the compressors according to the first and fifth embodiments
in that multiple radial passages 131a are provided in the rotor 121
in the compressor according to the 6th embodiment. Specifically,
the compressor according to the 6th embodiment is configured
including a first radial passage 131a1 and a second radial passage
131a2 (see FIG. 12). The first radial passage 131a1 is formed
inside the cylinder-shaped part 161 whose external shape is shown
in FIG. 10. The second radial passage 131a2 is formed inside a
cylinder-shaped part 162 discrete from the cylinder-shaped part
161. The cylinder-shaped part 162 is a part which is provided by
fitting a bush member into the hub part 121a in the rotor 121. The
first radial passage 131a1 is tapered in way that the diameter of
the first radial passage 131a1 becomes progressively smaller toward
its opening end on an inner-peripheral side of the rotor from its
opening end on an outer-peripheral side of the rotor. On the other
hand, the second radial passage 131a2 is tapered in way that the
diameter of the second radial passage 131a2 becomes progressively
larger toward its opening end on an inner-peripheral side of the
rotor from its opening end on an outer-peripheral side of the
rotor. In addition, the passage cross-section area of a
minimum-diameter portion of the second radial passage 131a2 is
smaller than the passage cross-section area of a minimum-diameter
portion of the first radial passage 131a1. In other words, the
opening end in the outer peripheral side of the second radial
passage 131a2 (that is, the minimum-diameter portion of the second
radial passage 131a1) is set smaller than the opening end in the
inner peripheral side of the first radial passage 131a1 (that is,
the minimum-diameter portion of the first radial passage
131a1).
[0101] This setting makes it easy for the coolant to flow into the
communicating part 135 through the first radial passage 131a1, and
unlikely allows the coolant to flow into the communicating part 135
through the second radial passage 131a2. As a result, the setting
causes the coolant to flow chiefly through the first radial passage
131a1.
[0102] In addition, the first radial passage 131a1 is arranged in a
location offset (shifted) from the radial passage 131b in the
driving shaft 10 in the direction reverse to the rotational
direction R, and the second radial passage 131a2 is arranged not
only in a location offset (shifted) from the first radial passage
131a1 in the direction reverse to the rotational direction R, but
also in a location offset (shifted) from the radial passage 131b in
the driving shaft 10 in the rotational direction R.
[0103] For this reason, the coolant having flown into the
communicating part 135 chiefly through the first radial passage
131a1 is caused to flow in the direction reverse to the rotational
direction R of the rotating rotor 121 as described above. Only
after making at least approximately one circuit along the
communicating part 135, the coolant is allowed to flow into the
radial passage 131b in the driving shaft 10. At this time, the mist
of oil having flown into the communicating part 135 through the
first radial passage 131a1 together with the coolant is centrifuged
at the communicating part 135. The mist of oil is discharged to the
crankcase through the second radial passage, before making
approximately one circuit along the communicating part and then
entering the radial passage in the driving shaft. This design
reduces the probability that the oil once centrifuged in the
communicating part 135 may be drawn into the radial passage 131b in
the driving shaft 10 under the influence of the flow of the
coolant, and accordingly heightens the centrifugal separation
function further.
[0104] In addition, the 6th embodiment makes it easy for the oil to
be discharged to the crankcase 5 through the second radial passage
131a2 more smoothly. That is because the opening end of the second
radial passage 131a2 in its inner periphery is set larger although
the minimum-diameter portion of the second radial passage 131a2 is
structured small, or although the opening end of the second radial
passage 131a2 in its outer periphery is structured small.
(Modification)
[0105] In the foregoing embodiments, the communicating part 135 is
formed in the inner peripheral surface 165 (or the press-fitting
surface) of the rotor 121. In the present invention, however, the
communicating part 135 may be formed in the outer peripheral
surface 167 (or the press-fitting surface) of the driving shaft 10.
Otherwise, the communicating part 135 may be formed both in the
inner peripheral surface 165 of the rotor 121 and in the outer
peripheral surface 167 of the driving shaft 10.
[0106] In the foregoing embodiments, the axial passage 31c in the
driving shaft 10 is provided along the center line of the driving
shaft 10. In the present invention, however, the axial passage 31c
in the driving shaft 10 may be eccentric to the center line of the
driving shaft 10, or may slant to the center line of the driving
shaft 10, as long as the centrifugal separation effect is
exerted.
[0107] In the foregoing embodiments, the radial passages 131b in
the driving shaft 10 and the radial passage 131a in the rotor 121
are orthogonal to the axial passage 31c in the driving shaft 10. In
the present invention, however, these radial passages 131b and 131a
may slant to the axial passage 31c in the driving shaft 10 as long
as the centrifugal separation effect is exerted.
[0108] The compressors according to the foregoing embodiments are
the swash variable displacement compressors in which the swash
plate main body 26 is fixed to the journal 25 so that the swash
plate main body 26 rotates integrally with the driving shaft 10.
However, the present invention is also applicable to a wobble
variable displacement compressor in which the swash plate main body
26 is rotatably put on the journal 25 so that the swash plate main
body 26 rotates unintegrally with the driving shaft 10. The present
invention is also applicable to variable displacement compressors
of any other types. It goes without saying that the present
invention is applicable to not only variable displacement
compressors but also fixed displacement compressors.
[0109] The present invention is not limited to the embodiments of
the present invention which have been described. The present
invention can be carried out as other various embodiments by
introducing modifications to the present invention depending on the
necessity.
[0110] The entire contents of Japanese Patent Application No.
2007-187365 (filed on Jul. 18, 2007) and Japanese Patent
Application No. 2007-187369 (filed on Jul. 18, 2007) are
incorporated in the description by reference.
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