U.S. patent application number 10/770757 was filed with the patent office on 2004-09-23 for compressor for and method of simultaneously cooling and cleaning gas.
Invention is credited to Fujii, Toshiro, Hoshino, Tatsuyuki, Nakane, Yoshiyuki, Okada, Masahiko.
Application Number | 20040184940 10/770757 |
Document ID | / |
Family ID | 32658628 |
Filed Date | 2004-09-23 |
United States Patent
Application |
20040184940 |
Kind Code |
A1 |
Nakane, Yoshiyuki ; et
al. |
September 23, 2004 |
Compressor for and method of simultaneously cooling and cleaning
gas
Abstract
A scroll type compressor includes a fixed scroll member and a
movable scroll member to define compression chambers. The movable
scroll member orbits relative to the fixed scroll member to
compress gas in the compression chambers. The compressed gas is
discharged to a discharge port. The compressor also includes a
filter chamber and a cooling chamber. The filter chamber
communicates with the discharge port for accommodating a first
filter to at least partially filter the compressed gas. The cooling
chamber is located adjacent to the filter chamber for containing
coolant fluid that cools the compressed gas in the filter
chamber.
Inventors: |
Nakane, Yoshiyuki;
(Kariya-shi, JP) ; Fujii, Toshiro; (Kariya-shi,
JP) ; Hoshino, Tatsuyuki; (Kariya-shi, JP) ;
Okada, Masahiko; (Kariya-shi, JP) |
Correspondence
Address: |
KNOBLE & YOSHIDA, LLC
Eight Penn Center
Suite 1350
1628 John F. Kennedy Blvd.
Philadelphia
PA
19103
US
|
Family ID: |
32658628 |
Appl. No.: |
10/770757 |
Filed: |
February 3, 2004 |
Current U.S.
Class: |
418/55.1 ;
418/83 |
Current CPC
Class: |
F04C 18/0215 20130101;
F04C 29/0092 20130101; F04C 29/04 20130101 |
Class at
Publication: |
418/055.1 ;
418/083 |
International
Class: |
F04C 018/00; F01C
021/04 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 5, 2003 |
JP |
2003-028401 |
Mar 10, 2003 |
JP |
2003-063608 |
Claims
What is claimed is:
1. A scroll type compressor including a fixed scroll member and a
movable scroll member to define compression chambers, the movable
scroll member orbiting relative to the fixed scroll member to
compress gas in the compression chambers, the compressed gas being
discharged to a discharge port, comprising: a filter chamber
communicating with the discharge port for accommodating a first
filter to at least partially filter the compressed gas; and a
cooling chamber located adjacent to the filter chamber for
containing coolant fluid that cools the compressed gas in the
filter chamber.
2. The scroll type compressor according to claim 1, wherein the
cooling chamber is located between the compression chambers and the
filter chamber.
3. The scroll type compressor according to claim 1, further
comprising an inner casing and an outer casing that define the
filter chamber, the inner casing being fixed to the fixed scroll
member, the outer casing being detachably fixed to the inner
casing.
4. The scroll type compressor according to claim 3, wherein the
first filter is supported in such a manner that the first filter is
sandwiched by the inner and outer casings.
5. The scroll type compressor according to claim 1, wherein the
first filter is located so as to be perpendicular to a first flow
direction in which the compressed gas flows in the filter chamber,
the first flow direction being substantially the same as a second
flow direction in which the compressed gas flows in the discharge
port.
6. The scroll type compressor according to claim 1, wherein the
filter chamber further accommodates a second filter, the first and
second filters being located along a first flow direction in which
the compressed gas flows in the filter chamber, an escape passage
being formed in such a manner that the compressed gas bypasses at
least one of the first and second filters.
7. The scroll type compressor according to claim 6, wherein the
compressed gas flows in the discharge port in a second flow
direction that is substantially the same as the first flow
direction.
8. The scroll type compressor according to claim 7, wherein the
first and second filters are located so as to be perpendicular to
the first flow direction.
9. The scroll type compressor according to claim 6, wherein the
first filter is located on an upstream side with respect to the
second filter, each of the first and second filters having a mesh,
a mesh size of the second filter being equal to or larger than that
of the first filter.
10. The scroll type compressor according to claim 6, wherein the
first filter is located on an upstream side with respect to the
second filter, the first filter having a first predetermined
receiving area, the second filter having a second predetermined
receiving area that is equal to or larger than the first
predetermined receiving area.
11. The scroll type compressor according to claim 6, further
comprising an open-close means for closing the escape passage when
a pressure of the compressed gas on an upstream side of the escape
passage is lower than a predetermined pressure, the open-close
means opening the escape passage when the pressure of the
compressed gas on the upstream side of the escape passage is equal
to or larger than the predetermined pressure.
12. The scroll type compressor according to claim 11, wherein the
open-close means further comprises a fixed support portion that is
fixed to the inner casing and a movable support portion for movably
supporting the first filter, the first filter contacting the fixed
support portion so as to close the escape passage, the first filter
moving away from the fixed support portion so as to open the escape
passage.
13. The scroll type compressor according to claim 12, wherein the
open-close means further comprises an elastic member for urging the
first filter to close the escape passage.
14. The scroll type compressor according to claim 6, wherein the
second filter is located on a downstream side with respect to the
first filter, the escape passage being formed in such a manner that
the compressed gas bypasses the first filter.
15. The scroll type compressor according to claim 6, wherein the
second filter is located on a downstream side with respect to the
first filter, the compressed gas passing through the second filter
without bypassing the second filter.
16. The scroll type compressor according to claim 6, wherein the
first and second filters are supported in such a manner that the
first and second filters are sandwiched between the inner and outer
casings.
17. The scroll type compressor according to claim 6, further
comprising a first filter mounting portion for placing the first
filter adjacent to the second filter at a predetermined distance
from the second filter.
18. The scroll type compressor according to claim 17, wherein the
first filter mounting portion is connected to the inner casing.
19. The scroll type compressor according to claim 17, wherein the
second filter has a frame, the first filter mounting portion being
connected to the frame of the second filter.
20. The scroll type compressor according to claim 1, wherein the
first filter further comprises a filter portion and a frame.
21. The scroll type compressor according to claim 20, wherein a
shape of the filter portion is different from that of the
frame.
22. The scroll type compressor according to claim 20, wherein the
first filter has a circular shape.
23. The scroll type compressor according to claim 20, wherein the
first filter has a rectangular shape.
24. The scroll type compressor according to claim 20, wherein the
first filter has a semicircular shape.
25. The scroll type compressor according to claim 20, wherein the
first filter has a planar shape.
26. The scroll type compressor according to claim 20, wherein the
first filter has a hemispherical shape.
27. The scroll type compressor according to claim 1, wherein
flow-dividing fins are provided in the cooling chamber for dividing
flow of the coolant fluid.
28. The scroll type compressor according to claim 1, further
comprising a suction port for introducing the compressed gas into
the compression chambers.
29. The scroll type compressor according to claim 1, wherein an
inlet is formed at the filter chamber for communicating with the
discharge port, an outlet being formed at the filter chamber for
leading the compressed gas to an external circuit.
30. A method of processing compressed gas in a compressor that
forms a compression chambers for compressing the gas, a filter
chamber having a filter and a cooling chamber that is located
adjacent to the filter chamber for containing coolant fluid, the
method comprising the steps of: transmitting cooling temperature of
the coolant fluid to the filter chamber; cooling the compressed gas
in the filter chamber; and removing foreign substances in the
compressed gas through the filter in the filter chamber
simultaneously with said cooling.
31. The method according to claim 30, further comprising the steps
of: transmitting the cooling temperature of the coolant fluid to
the compression chambers; and cooling the compressed gas in the
compression chambers simultaneously with said cooling the
compressed gas in the filter chamber.
32. The method according to claim 30, wherein the compressor is a
scroll type compressor.
33. A compressor for compressing gas, comprising: a filter chamber
for accommodating a filter so as to at least partially filter the
compressed gas; and a cooling chamber located adjacent to the
filter chamber for containing coolant fluid so that cooling
temperature of the coolant fluid is transmitted to the filter
chamber.
34. The compressor according to claim 33, further comprising
compression chambers located adjacent to the cooling chamber for
compressing the gas so that the cooling temperature of the coolant
fluid is transmitted to the compression chambers.
35. A cooling circuit for cooling gas in a compressor that
compresses the gas, comprising: a filter chamber located in the
compressor and accommodating a filter to filter at least partially
the compressed gas; a cooling chamber located in the compressor
adjacent to the filter chamber for passing coolant fluid; a heat
exchanger connected to the cooling chamber for cooling the coolant
fluid from the cooling chamber; and a pump connected to the heat
exchanger for supplying the coolant fluid to the cooling chamber.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a compressor that
compresses gas to be supplied preferably to a fuel cell, and more
particularly to a technique for cooling the gas and removing
foreign substances in the gas, such as abrasion powder, from the
gas.
[0002] In a scroll type compressor, as gas is compressed, the
temperature of the gas rises. Then, the compressed gas is
discharged from a compression chamber. When the discharged gas at a
high temperature flows out from the compressor to an external
circuit, it is possible for the high temperature gas to give a
thermally adverse effect to a device on a downstream side in the
external circuit. As disclosed in Japanese Unexamined Patent
Publication No. 2002-295386, a technique is known to avoid such
thermally adverse effect on the downstream device, and the gas is
cooled to a temperature that gives no thermally adverse effect to
the downstream device before the gas flows out of a compressor. In
the above cooling technique, a cooling chamber is disposed adjacent
to a compression chamber, and a gas cooler that has a gas passage
leading to a discharge port is arranged adjacent to the cooling
chamber. Therefore, heat is exchanged between coolant fluid in the
cooling chamber and the discharged gas in the gas passage so that
the discharged gas is cooled while the discharged gas passes
through the gas passage.
[0003] Meanwhile, when the scroll type compressor is operated,
spiral walls of movable and fixed scroll members slide relative to
each other, and tip seals at the axially distal ends of the spiral
walls slide relative to base plates of the scroll members. Sliding
surfaces abrade due to these sliding actions, and the abrasion
produces abrasion powder. The abrasion powder is mixed in the gas
and flows out to the external circuit. Although it adversely
affects the downstream device, preventive measures against such
abrasion powder have not been taken in the scroll type compressor
in prior art.
[0004] Incidentally, Japanese Unexamined Patent Publication No.
2000-213831 discloses a technique in which a filter is provided in
a conduit for collecting the abrasion powder in the gas that flows
in the conduit. The above filter collects abrasion powder that is
produced in the compressor and that is discharged to the outside of
the compressor with the gas so as to prevent the abrasion powder
from flowing into the downstream device. However, in the above
structure, there is a limit to enlarge a cross section of a filter
passage. Because of the small cross-sectional area, the filter is
easily clogged, and the compression pressure is reduced.
SUMMARY OF THE INVENTION
[0005] The present invention provides a technique to effectively
cool gas and to simultaneously remove foreign substances from the
gas in a compressor before the discharged gas from a discharge port
flows out to an external circuit.
[0006] According to the present invention, a scroll type compressor
includes a fixed scroll member and a movable scroll member to
define compression chambers. The movable scroll member orbits
relative to the fixed scroll member to compress gas in the
compression chambers. The compressed gas is discharged to a
discharge port. The compressor also includes a filter chamber and a
cooling chamber. The filter chamber communicates with the discharge
port for accommodating a first filter to at least partially filter
the compressed gas. The cooling chamber is located adjacent to the
filter chamber for containing coolant fluid that cools the
compressed gas in the filter chamber.
[0007] The present invention also provides a method of processing
compressed gas in a compressor. The compressor forms a compression
chambers for compressing the gas, a filter chamber having a filter
and a cooling chamber that is located adjacent to the filter
chamber for containing coolant fluid. The method includes the steps
of transmitting cooling temperature of the coolant fluid to the
filter chamber, cooling the compressed gas in the filter chamber
and removing foreign substances in the compressed gas through the
filter in the filter chamber simultaneously with the above cooling
step.
[0008] The present invention also provides a compressor for
compressing gas. The compressor includes a filter chamber and a
cooling chamber. The filter chamber accommodates a filter so as to
at least partially filter the compressed gas. The cooling chamber
is located adjacent to the filter chamber for containing coolant
fluid so that cooling temperature of the coolant fluid is
transmitted to the filter chamber.
[0009] The present invention also provides a cooling circuit for
cooling gas in a compressor that compresses the gas. The cooling
circuit includes a filter chamber, a cooling chamber, a heat
exchanger and a pump. The filter chamber is located in the
compressor and accommodates a filter to filter at least partially
the compressed gas. The cooling chamber is located in the
compressor adjacent to the filter chamber for passing coolant
fluid. The heat exchanger is connected to the cooling chamber for
cooling the coolant fluid from the cooling chamber. The pump
connected to the heat exchanger for supplying the coolant fluid to
the cooling chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The features of the present invention that are believed to
be novel are set forth with particularity in the appended claims.
The invention together with objects and advantages thereof, may
best be understood by reference to the following description of the
presently preferred embodiments together with the accompanying
drawings in which:
[0011] FIG. 1 is a longitudinal cross-sectional view of a scroll
type compressor according to a first preferred embodiment of the
present invention;
[0012] FIG. 2 is a cross-sectional view of the scroll type
compressor taken along the line II-II in FIG. 1;
[0013] FIG. 3 is a perspective view of a filter according to the
first preferred embodiment of the present invention;
[0014] FIG. 4 is a partially enlarged cross-sectional view of a
scroll type compressor according to a second preferred embodiment
of the present invention;
[0015] FIG. 5 is a perspective view of a filter on an upstream side
according to the second preferred embodiment of the present
invention;
[0016] FIG. 6 is a perspective view of a filter according to a
first alternative embodiment of the present invention;
[0017] FIG. 7 is a perspective view of a filter according to a
second alternative embodiment of the present invention;
[0018] FIG. 8 is a perspective view of a filter according to a
third alternative embodiment of the present invention;
[0019] FIG. 9 is a cross-sectional view showing a filter according
to a fourth alternative embodiment of the present invention;
[0020] FIG. 10 is a cross-sectional view showing a support
structure for a filter on an upstream side according to a fifth
alternative embodiment;
[0021] FIG. 11 is a cross-sectional view showing a support
structure for a filter on an upstream side according to a sixth
alternative embodiment; and
[0022] FIG. 12 is a cross-sectional view showing an open-close
structure of an escape passage for a filter on an upstream side
according to a seventh alternative embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] A first preferred embodiment will be now described in
reference to FIGS. 1 through 3. FIG. 1 is a longitudinal
cross-sectional view of a scroll type electric compressor 10
according to the first preferred embodiment of the present
invention. FIG. 2 is a cross-sectional view of the compressor 10
taken along the line II-II in FIG. 1. FIG. 3 is a perspective view
of a filter. The left and right sides of FIG. 1 respectively
correspond to the front and rear sides of the compressor 10.
[0024] The present preferred embodiment is applied for compressing
gas, and it is more particularly applied for compressing air which
is supplied to a fuel cell in an electric vehicle. An outer hull of
the compressor 10 includes a front housing 11 and a rear housing 12
both of which are made of aluminum or aluminum alloy. A rotary
shaft 13 is rotatably supported in the front and rear housings 11
and 12. A rotor 14 constituting an electric motor M is rotatably
mounted on the rotary shaft 13 in the rear housing 12. A stator 16
constituting the electric motor M is fixedly arranged on the inner
circumferential surface of the rear housing 12 so as to surround
the rotor 14.
[0025] The front housing 11 includes a fixed scroll member 20, a
filter casing 41 and a support housing 21. The filter casing 41 is
fixedly joined to the front end of the fixed scroll member 20. The
support housing 21 is fixedly joined to the rear end of the fixed
scroll member 20 and to the front end of the rear housing 12. The
fixed scroll member 20 includes a fixed base plate 20a that has a
substantially disc-shaped configuration and a fixed spiral wall 20b
that extends from the rear surface of the fixed base plate 20a.
[0026] A crankshaft 17 is provided at the front end of the rotary
shaft 13 and is offset from an axis L of the rotary shaft 13 by a
predetermined length E of eccentricity. A movable scroll member 24
is rotatably supported by the crankshaft 17 through a pair of
bearings 25 so as to face the fixed scroll member 20. The movable
scroll member 24 includes a movable base plate 24a that is
substantially disc-shaped and a movable spiral wall 24b that
extends from the front surface of the movable base plate 24b.
[0027] The fixed and movable scroll members 20 and 24 are arranged
so as to engage with each other. The distal end surfaces of the
fixed and movable spiral walls 20b and 24b respectively contact the
movable and fixed base plates 24a and 20a at tip seals 20c and 24c.
The fixed spiral wall 20b overlaps the movable spiral wall 24b to
contact each other at a plurality of points. Therefore, the fixed
base plate 20a and the fixed spiral wall 20b of the fixed scroll
member 20 as well as the movable base plate 24a and the movable
spiral wall 24b of the movable scroll member 24 define a plurality
of falcate compression chambers 26.
[0028] A boss 24d is formed at the intermediate portion of the
movable base plate 24a of the movable scroll member 24. The boss
24d axially protrudes toward the front side of the compressor 10.
An inserting recess 24e is formed in the boss 24d for accepting the
crankshaft 17 thereinto. In the inserting recess 24e, a bottom wall
24f of the boss 24d is formed at the front side opposite to an
opening and rear side where the crankshaft 17 is inserted. Thus,
the crankshaft 17 protrudes from the movable base plate 24a toward
the fixed base plate 20a. Consequently, the compressor 10 is
shortened along the axis L of the rotary shaft 13 by a partial
length of the crankshaft 17 that protrudes from the movable base
plate 24a toward the fixed base plate 20a.
[0029] A discharge port 20d is formed in the center of the fixed
base plate 20a of the fixed scroll member 20. A suction port 20e is
formed in the outer circumferential wall of the fixed scroll member
20. A self-rotation preventing mechanism 31 includes a crankshaft
27 and bearings 28 and 29. The self-rotation preventing mechanism
31 is located between the movable base plate 24a of the movable
scroll member 24 and the inner wall surface of the support housing
21 that faces the movable base plate 24a of the movable scroll
member 24.
[0030] As the rotary shaft 13 is rotated by the electric motor M,
the movable scroll member 24 orbits around the axis of the fixed
scroll member 20 by the crankshaft 17. At the same time, the
self-rotation preventing mechanism 31 prevents the movable scroll
member 24 from self-rotating while it allows the movable scroll
member 24 to orbit around the axis of the fixed scroll member 20.
As the compression chambers 26 move inwardly from an outer
circumferential side of the fixed and movable spiral walls 20b and
24b by the orbital movement, the compression chambers 26 reduce in
volume. Thereby, the air introduced from the suction port 20e into
the compression chambers 26 is compressed. The compressed air is
discharged from the compression chambers 26 to a filter chamber 44
through the discharge port 20d when the compression chambers 26
have approached the center of the fixed base plate 20a.
[0031] A cooling chamber 32 is defined between the front surface of
the fixed scroll member 20 and the filter casing 41, the filter
casing 41 is fixed to the fixed scroll member 20. Specifically, a
recess 32c is formed at the front side of the fixed base plate 20a
of the fixed scroll member 20, and the filter casing 41 is fixed to
the front surface of the fixed base plate 20a so as to cover the
recess 32c. Accordingly, the cooling chamber 32 is adjacent to the
compression chambers 26 across the fixed base plate 20a.
[0032] As shown in FIG. 2, the cooling chamber 32 is formed in a
substantially U-shaped manner so as to surround the discharge port
20d. The cooling chamber 32 has a coolant inlet 32a for flowing
cooling water as coolant fluid into the cooling chamber 32 and a
coolant outlet 32b for removing the cooling water. A plurality of
flow-dividing fins 33 is provided in the cooling chamber 32. The
flow-dividing fins 33 divide the flow of the cooling water flowing
in from the coolant inlet 32a, and the cooling water flows toward
the coolant outlet 32b. In the present preferred embodiment, the
flow-dividing fins 33 extend from the front surface of the fixed
base plate 20a of the fixed scroll member 20. The cooling chamber
32 partially constitutes a cooling circuit. As shown in FIG. 2, a
heat exchanger and a 10 pump are provided in the cooling circuit.
The heat exchanger cools the high-temperature cooling water that
flows out from the coolant outlet 32b. The pump supplies the
cooling water that has been cooled into the cooling chamber 32
through the coolant inlet 32a. Pure water generated by cell
reaction at a fuel cell FC as shown in FIG. 1 is utilized as the
cooling water that circulates in the cooling circuit.
[0033] Referring back to FIG. 1, the filter casing 41 has a
two-part structure including an inner casing 41a at the rear side
and an outer casing 41b at the front side. The inner casing 41a is
fixed to the front surface of the fixed scroll member 20 by a
predetermined number of bolts 42 while the outer casing 41b is
fixed to the inner casing 41a by a predetermined number of bolts
43. Namely, the outer casing 41b is detachable from the inner
casing 41a. As necessary, the outer casing 41b is detached from the
inner casing 41a. The inner and outer casings 41a and 41b define
the filter chamber 44. The filter chamber 44 is adjacent to the
cooling chamber 32 across the inner casing 41a. Namely, the cooling
chamber 32 is located between the compression chambers 26 and the
filter chamber 44. Also, the inner casing 41a contacts the
flow-dividing fins 33.
[0034] Still referring to FIGS. 1 and 2, the filter chamber 44
accommodates a filter 45 for removing foreign substances when the
compressed air is introduced from the discharge port 20d into the
filter chamber 44. The filter 45 includes a filter portion 45a for
removing the foreign substances and a frame 45b arranged around the
edges of the filter portion 45a for supporting the filter portion
45a.
[0035] The filter 45 is schematically illustrated in FIG. 3. In the
filter 45, the frame 45b preferably includes a rib 45c for
reinforcing. In order to enhance capacity for collecting the
foreign substances and cooling effect, the filter portion 45a is
preferably a pleated type filter element that has been formed by
bending a flat stainless screen in zigzags. The filter 45 is
supported in such a manner that the filter 45 is sandwiched by the
inner and outer casings 41a and 41b. As shown in FIG. 1, the filter
portion 45a is suspended in the filter chamber 44.
[0036] Referring to FIG. 1, a communication hole 41c is formed as
an inlet in the center of the inner casing 41a. The filter chamber
44 communicates with the discharge port 20d of the compression
chamber 26 through the communication hole 41c. An outlet 41d is
formed in the center of the outer casing 41b. That is, the
compressed air discharged from the discharge port 20d of the
compression chamber 26 is inputted to the filter chamber 44 through
the communication hole 41c. After passing through the filter 45,
the compressed air is outputted through the outlet 41d to the fuel
cell FC, which is located outside of the compressor 10. The
compressed air flows in the filter chamber 44 substantially in the
same direction as the compressed air flows in the discharge port
20d as shown by an arrow in FIG. 1. Also, the filter 45 is located
so as to be perpendicular to the above flow direction.
[0037] Referring to FIGS. 1 and 2, as the compressor 10 is
operated, the cooling water flows into the cooling chamber 32 from
the coolant inlet 32a. The cooling water flowing into the cooling
chamber 32 cools the air that is being compressed in the
compression chambers 26 and the discharged air in the filter
chamber 44. Namely, heat is exchanged between the cooling water in
the cooling chamber 32 and the compressed air in the compression
chambers 26 through the fixed base plate 20a as well as between the
cooling water and the compressed gas in the filter chamber 44
through the inner casing 41a. More specifically, cooling
temperature of the cooling water is transmitted to the compressed
air in the compression chambers 26 through the fixed base pate 20a
as well as the compressed gas in the filter chamber 44 through the
inner casing 41a. The cooling water that has been used for cooling
flows out from the coolant outlet 32b and is substantially cooled
by the heat exchanger to circulate back into the cooling chamber 32
by the pump. Namely, as the cooling water circulates in the cooling
circuit, the temperature of the cooling water repeatedly rises and
lowers. A part of the cooling water that flows out from the coolant
outlet 32b is discarded, and the same amount of the pure water
generated at the fuel cell FC is added into the cooling circuit for
the discarded part.
[0038] In accordance with the operation of the compressor 10, the
movable spiral wall 24b rotates relative to the fixed spiral wall
20b while the movable spiral wall 24b contacts the fixed spiral
wall 20b. That is, the movable spiral wall 24b slides over the
fixed spiral wall 20b. Also, the tip seals 20c and 24c respectively
slide over the movable and fixed base plate 24a and 20a. Thereby,
sliding surfaces abrade to produce abrasion powder. The abrasion
powder is mixed in the compressed air and is sent to the filter
chamber 44 through the discharge port 20d and the communication
hole 41c. When the discharged air passes through the filter 45 in
the filter chamber 44, the filter 45 collects the abrasion powder
in the discharged air and the discharged air is cooled
substantially at the same time. Namely, as the abrasion powder is
removed from the discharged air in the filter chamber 44 by the
filter 45, the cooling water in the cooling chamber 32 cools the
discharged air. The filtered air having a low temperature is
outputted to the outside or an external circuit of the compressor
10 from the outlet 41d.
[0039] In the first preferred embodiment, following effects are
obtained. As described above, in the present preferred embodiment,
the filter chamber 44 accommodating the filter 45 is formed in the
compressor 10 and is adjacent to the cooling chamber 32.
Accordingly, since cleaning and cooling of the discharged air are
simultaneously conducted in one space, the space is efficiently and
logically utilized. Also, since the cooling chamber 32 is adjacent
to the compression chambers 26, cooling action is applied to the
compressed air in the compression chambers 26 and the filter
chamber 44. Accordingly, the compressed air is effectively
cooled.
[0040] Also, in the present preferred embodiment, the filter
chamber 44 is formed in the compressor 10. In this regard, a
conduit in the external circuit is generally not large enough in
diameter for efficient circulation. A filter area size is limited
to a small cross-sectional area of the conduit in the external
circuit. No significant limitation is applicable for the
cross-sectional size in the present preferred embodiment since the
filter is in the compressor. The filter 45 is enlarged in the
preferred embodiment in an orthogonal direction relative to the
compressed air flow direction in which the compressed air flows in
the filter chamber 44. Based on this design, the area of the filter
45 is substantially larger than that in the external circuit, and
the capacity for collecting the foreign substances is also
substantially enhanced. Consequently, since a flow rate of the air
is reduced due to the large area, cooling time of the compressed
air in the filter chamber 44 is longer, and a strong cooling effect
is obtained.
[0041] In the present preferred embodiment, the cooling chamber 32
is formed between the compression chambers 26 and the filter
chamber 44. The heat is exchanged between the cooling water in the
cooling chamber 32 and the compressed air to cool the compressed
air in the compression chambers 26 and the filter chamber 44.
Therefore, in comparison to cooling the compressed air only in the
filter chamber 44, the cooling effect on the air is further
enhanced.
[0042] In the present preferred embodiment, the filter casing 41
has the two-part structure including the inner and outer casings
41a and 41b. The inner casing 41a is fixed to the fixed scroll
member 20, and the outer casing 41b is detachably fixed to the
inner casing 41a. Since the outer casing 41b is detached from the
inner casing 41a as necessary, the filter 45 in the filter chamber
44 is easily replaced or cleaned. Also, the filter casing 41 is
connected to the fixed scroll member 20 so as to provide the filter
chamber 44. To an existing compressor, a filter casing is newly
placed to a housing so that a filter chamber is newly provided for
the existing compressor. Therefore, the above simple design change
enables the existing scroll type electric compressor to cool air
and remove foreign substances.
[0043] A plurality of the flow-dividing fins 33 is provided in the
cooling chamber 32 and protrudes from the fixed base plate 20a of
the fixed scroll member 20. The flow-dividing fins 33 contact the
inner casing 41a. Thus, a heat transfer area between the cooling
chamber 32 and the compression chambers 26 as well as between
cooling chamber 32 and the filter chamber 44 is increased.
Consequently, the cooling effect is enhanced.
[0044] A second preferred embodiment will be now described in
reference to FIGS. 4 and 5. Since the second preferred embodiment
is modified from the above-described first preferred embodiment,
only the modified parts will be described, and the same description
will be omitted. FIG. 4 is a partially enlarged cross-sectional
view of a scroll type compressor according to the second preferred
embodiment of the present invention. As shown in FIG. 4, in the
present preferred embodiment, an additional filter 55 is added in
the filter chamber 44 on an upstream side, that is, a rear side as
indicated in the right in FIG. 4 relative to the filter 45 of the
above-described first preferred embodiment. The two filters 45 and
55 are located along the compressed air flow direction. For the
convenience of the description, the filter 55 located at the
upstream side and the filter 45 located at a downstream side or the
front side are respectively referred to as a first filter and a
second filter. Since the second filter 45 has substantially the
same structure as in the first preferred embodiment, the
description for the second filter 45 is omitted.
[0045] As schematically shown in FIG. 5, the first filter 55
includes a filter portion 55a for removing the foreign substances
and a frame 55b arranged around the edges of the filter portion 55a
for supporting the filter portion 55a. The frame 55b preferably
includes a rib 55c for reinforcing. In order to enhance the
capacity for collecting the foreign substances and the cooling
effect, the filter portion 55a is preferably a pleated type filter
element that a flat stainless screen is bent in zigzags as
similarly done to the filter portion 45a of the second filter 45 as
described with respect to FIG. 3. In addition to the stainless
filter element, filter elements made of material such as steel,
aluminum alloy, resin and fabric are also used for either of the
first and second filter portions 55a and 45a. The first and second
filter portions 55a and 45a have a micro structure or a mesh in
which circular or square pores are formed in a plate material.
[0046] A plurality of mounting portions or first filter mounting
portions 55d is formed at the periphery of the frame 55b. Two
mounting portions 55d are shown in FIG. 5. The end portions of the
mounting portions 55d are outwardly bent. The end portion of each
mounting portion 55d is fixed to an inner surface of the inner
casing 41a by a bolt 57 so that the first filter 55 is supported in
the filter chamber 44 as shown in FIG. 4. Thereby, the filter
portion 55a of the first filter 55 is supported in the filter
chamber 44. Also, an escape passage 56 bypasses the first filter 55
and leads to the second filter 45. The first and second filters 55
and 45 are placed at a predetermined interval along the compressed
air flow direction or a horizontal direction in FIG. 4. The first
and second filters 55 and 45 are both located so as to face the
discharge port 20d. Namely, the first and second filters 55 and 45
are located so as to be perpendicular to the compressed air flow
direction in the filter chamber 44.
[0047] In general, a mesh size M1 of the first filter 55 and a mesh
size M2 of the second filter 45 preferably satisfy the following
inequality. The mesh size is determined by the number of mesh
openings in a square inch.
M1.ltoreq.M2
[0048] In the present preferred embodiment, the mesh size M1 and M2
of the first and second filters 55 and 45 satisfy the following
inequality:
M1<M2
[0049] Namely, the mesh size M1 of the first filter 55 is smaller
than the mesh size M2 of the second filter 45. More precisely, the
mesh size of the first filter portion 55a in the first filter 55
ranges from 25 to 40 while the mesh size of the second filter
portion 45a in the second filter 45 is approximately 100.
[0050] In general, a receiving area A1 of the filter portion 55a
and a receiving area A2 of the filter portion 45a preferably
satisfy the following inequality. The receiving area of the filter
in the present specification means the area of the filter portion
that receives the compressed air.
A1.ltoreq.A2
[0051] In the preferred embodiment, the receiving areas A1 and A2
of the first and second filters 55 and 45 satisfy the following
inequality:
A1<A2
[0052] Namely, the receiving area A1 of the first filter 55 on the
upstream side is smaller than the receiving area A2 of the second
filter 45 on the downstream side.
[0053] According to the above scroll compressor 10 as shown in FIG.
4, while the compressor 10 is operated, the compressed air is
discharged from the discharge port 20d and is sent to the filter
chamber 44 through the communication hole 41c. The compressed air
passes through the first and second filters 55 and 45 in this
order. Therefore, the foreign substances such as the abrasion
powder mixed in the compressed air are collected by the first and
second filters 55 and 45, and the compressed air is cooled by the
cooling water in the cooling chamber 32. Then, the filtered
compressed air at a lower temperature is outputted from the outlet
45d to the external circuit of the compressor 10.
[0054] According to the scroll compressor 10 of the second
preferred embodiment as constructed above, substantially the same
advantageous effects are obtained as described in the first
preferred embodiment.
[0055] Furthermore, the foreign substances such as the abrasion
powder mixed in the compressed air are collected by the first and
second filters 55 and 45 in a sequential manner so that the
compressed air is cleaned through two filters over a longer period
of time. Also, as the air flowing in the filer chamber 44 passes
through the two filters 55 and 45, the flow rate of the air is
further reduced. Therefore, the compressed air is effectively
cooled. The escape passage 56 is formed so that the compressed air
bypasses the first filter 55. The escape passage 56 includes the
space between the first filter 55 and the inner casing 41a as
indicated by "X" in FIG. 5. If the first filter 55 is clogged, the
compressed air bypasses the first filter 55 through the escape
passage 56. Consequently, the pressure loss due to the clogged
filter is prevented or reduced. Even though the first filter 55 is
clogged, the compressor 10 effectively performs. In this regard,
life of the scroll compressor 10 is extended. As described above,
not only the foreign substances such as the abrasion powder mixed
in the compressed air are substantially collected but also the
temperature is substantially lower in the compressed air that is
discharged from the outlet 41d of the filter chamber 44.
[0056] Also, the escape passage 56 are formed so as to bypass the
first filter 55 that is located on the upstream side. Thus, even
though the compressed air bypasses the first filter 55, the foreign
substances in the compressed air are eventually collected by the
second filter 45 on the downstream side. Consequently, the foreign
substances such as the abrasion powder mixed in the compressed air
are effectively collected. Also, if the second filter 45 is
clogged, the first and second filters 55 and 45 are replaced or
cleaned. Without replacement or cleaning, the amount of clogged
material on the second filter 45 is one indication of remaining
life of the compressor 10.
[0057] The first and second filters 55 and 45 are located so as to
face the discharge port 20d. Thus, the compressed air discharged
from the discharge port 20d effectively passes through the two
filters 55 and 45. Consequently, the foreign substances such as the
abrasion powder mixed in the compressed air are effectively
collected. Also, the two filters 55 and 45 are compactly installed
in the compressor 10.
[0058] The mesh size M1 of the first filter 55 is smaller than the
mesh size M2 of the second filter 45. Thus, the foreign substances
such as the abrasion powder mixed in the compressed air are
collected separately according to the size through the first filter
55 on the upstream side and then the second filter 45 on the
downstream side.
[0059] The receiving area A1 of the first filter 55 on the upstream
side is smaller than the receiving area A2 of the second filter 45
on the downstream side. Thus, the compressed air smoothly flows
toward the second filter 45 on the downstream side after passing
through the first filter 55 on the upstream side so that the
foreign substances such as the abrasion powder mixed in the
compressed air are effectively collected.
[0060] The second filter 45 is located on the downstream side with
respect to first filter 55, and an escape passage is not formed at
the second filter 45. Thus, since the compressed air cannot bypass
the second filter 45, the foreign substances in the compressed air
are eventually collected by the second filter 45. It is possible to
avoid the flow of the foreign substances to the external circuit of
the compressor 10 due to the insufficient cleaning which is
expected when the compressed air supposedly bypasses the second
filter 45.
[0061] The present invention is not limited to the above-described
preferred embodiments, and the above-described preferred
embodiments are also modified according to the present invention in
the following manners.
[0062] The shapes of the first and second filters 55 and 45 are
circular in the above-described preferred embodiments. However, the
outer shapes of the first and second filters 55 and 45 are changed.
For example, in a first alternative embodiment, the shape of at
least one of the first and second filters 55 and 45 is
substantially rectangular as shown in FIG. 6. In a second
alternative embodiment, the shape of at least one of the first and
second filters 55 and 45 is substantially semicircular as shown in
FIG. 7.
[0063] As shown in FIG. 8, the filter 55 or 45 has a substantially
rectangular shape, and the shape of the filter portion 55a or 45a
is different from the shape of the frame 55b or 45b in a third
alternative embodiment. In this case, the filter portion 55a or 45a
avoids holes H1 for inserting bolts and a hole H2 that leads to the
coolant inlet 32a or the coolant outlet 32b of the cooling chamber
32 as shown in FIG. 2, which are formed in the frame 55b or 45b.
Namely, the shape of the filter portion 55a or 45a is appropriately
changed in accordance with the design requirements including the
location for inserting bolts, the location for the coolant inlet
32a and the coolant outlet 32b of the cooling chamber 32, and the
location for the communication hole 41c and the outlet 41d of the
filter chamber 44 in the filter casing 41.
[0064] The first and second filters 55 and 45 have planar shapes in
the above-described preferred embodiment. However, in a fourth
alternative embodiment, the first and second filters 55 and 45 have
substantially hemispherical shapes as shown in FIG. 9. The first
filter 55 is connected to the inner casing 41a of the filter casing
41 in the above-described second preferred embodiment. However, as
shown in FIG. 10, the first filter 55 is connected to the frame 45b
of the second filter 45 in a fifth alternative embodiment. In this
case, the end portion of each mounting portion 55d of the frame 55b
of the first filter 55 is similarly fixed to the frame 45b of the
second filter 45 by a bolt that is not shown in the drawings as the
above description. Thereby, the filter portion 55a of the first
filter 55 is suspended in the filter chamber 44, and a part of the
escape passage 56 is formed between the frame 55b of the first
filter 55 and the inner casing 41a.
[0065] As shown in FIG. 11, the frame 45b of the second filter 45
and the frame 55b of the first filter 55 are sandwiched between the
inner and outer casings 41a and 41b in a sixth alternative
embodiment. Thereby, the frame 45b of the second filter 45 and the
frame 55b of the first filter 55 are supported. A ring-shaped
spacer 50 is interposed between the first filter frame 55b and the
second filter frame 45b. Therefore, an interval is maintained
between the first and second filters 55 and 45. In this case, an
escape passage 56 includes through holes that are formed in the
first filter frame 55b. Meanwhile, the spacer 50 is formed
integrally with either of the first filter frame 55b or the second
filter frame 45b, and the number of components is reduced.
[0066] As shown in FIG. 12, an escape passage 56 at the first
filter 55 is formed so as to be opened and closed by an open-close
means in a seventh alternative embodiment. The open-close means
closes the escape passage 56 when the compressed air pressure on
the upstream side relative to the first filter 55 is smaller than a
predetermined pressure. The open-close means opens the escape
passage 56 when the compressed air pressure on the upstream side
relative to the first filter 55 is equal to or larger than the
predetermined pressure. Namely, a support member 58 is arranged at
the inner casing 41a. The support member 58 includes a fixed
support portion 58a that has a ring shape and a plurality of
movable support portions 58b that extends from the fixed support
portion 58a. The fixed support portion 58a is fixed to the inner
casing 41a. The end portions of the movable support portions 58b
movably support the first filter frame 55b in an axial direction as
shown in a horizontal direction in FIG. 12. The movable support
portions 58b are arranged in a circumferential direction of the
support member 58. Therefore, a part of the escape passage 56 is
formed between the movable support portions 58b. The first filter
frame 55b contacts the fixed support portion 58a to close the
escape passage 56 as shown by a solid line in FIG. 12. The first
filter frame 55b separates itself from the fixed support portion
58a to open the escape passage 56 as shown by a double-dotted line
in FIG. 12. Furthermore, an elastic member 59 such as a coil spring
is interposed between the first filter frame 55b and the movable
support portions 58b for urging the first filter 55 in a direction
in which the escape passage 56 are closed or rightward in FIG. 12.
That is, the direction is to urge the first filter 55 to close the
escape passage 56. The first filter 55, the support member 58 and
the elastic member 59 constitute an open-close means of the present
invention.
[0067] As constructed above, the first filter 55 is urged by the
elastic member 59 to close the escape passage 56 when the first
filter 55 is at a position as shown by the solid line in FIG. 12.
Thereby, the compressed air discharged from the discharge port 20d
through the communication hole 41c passes through the first filter
55. Consequently, the foreign substances such as the abrasion
powder mixed in the compressed air are effectively collected by the
first filter 55.
[0068] Also, when the first filter 55 is clogged and the compressed
air pressure on the upstream side relative to the first filter 55
is equal to or more than the predetermined pressure, the first
filter 55 is forced to move against the urging of the elastic
member 59 to open the escape passage 56 at a position as shown by
the double-dotted line in FIG. 12. Thereby, the compressed air
bypasses the first filter 55 through the opened escape passage 56.
Consequently, the pressure loss due to the clogging of the first
filter 55 is substantially prevented or reduced. As described
above, even though the first filter 55 is clogged, the compressor
10 effectively performs without cleaning or replacing the clogged
filter 55. Thus, the life of the scroll compressor 10 is extended
beyond the point when the first filter 55 is clogged.
[0069] Since the first filter 55, the support member 58 and the
elastic member 59 constitute the open-close means according to the
present invention as described above, the first filter 55
effectively functions as a valve body. Meanwhile, instead of the
above open-close means, another alternative embodiment utilizes a
known escape valve at an escape passage in the filter casing 41 for
bypassing the first filter 55.
[0070] Also, in an eighth alternative embodiment, in the second
filter 45, an escape passage is similarly formed so as to be opened
and closed by an open-close means as in the above first filter 55.
The open-close means usually closes the escape passage while the
open-close means opens the escape passage when the pressure of the
compressed air on the upstream side relative to the second filter
45 is equal to or larger than a predetermined pressure.
[0071] The recess 32c is formed in the fixed base plate 20a of the
fixed scroll member 20 for defining the cooling chamber 32 in the
above-described preferred embodiments. However, in a ninth
alternative embodiment, the recess 32c is formed in the inner
casing 41a of the filter casing 41, or in both the fixed base plate
20a and the inner casing 41a.
[0072] Also, in a tenth alternative embodiment, an additional
cooling chamber is defined on the front side of the filter casing
41 for cooling the discharged air in the filter chamber 44 from
both the front side and the rear side of the filter chamber 44.
[0073] The flow-dividing fins 33 are formed in the cooling chamber
32. However, in an eleventh alternative embodiment, the
flow-dividing fins 33 are formed on the rear side of the inner
casing 41a of the filter casing 41, or are omitted.
[0074] The above-described preferred embodiments apply to the
compressor for compressing the gas, more particularly the air,
which is supplied to the fuel cell FC of the electric vehicle.
However, in a twelfth alternative embodiment, the present invention
is applied to a compressor in an air conditioner or a refrigerating
device.
[0075] The two filters 55 and 45 in the second preferred embodiment
are located. However, in a thirteenth alternative embodiment, three
filters or more are located along the flow direction of the gas. An
escape passage is formed so as to bypass at least one of the
filters. Also, the first and second filters 55 and 45 are located
so as to be offset from the discharge port 20d and do not face the
discharge port 20d.
[0076] In the above-mentioned preferred embodiments, the present
invention is applied to a scroll type compressor. However, the
present invention is also applied to other type compressors.
[0077] The present examples and embodiments are to be considered as
illustrative and not restrictive, and the invention is not to be
limited to the details given herein but may be modified within the
scope of the appended claims.
* * * * *