U.S. patent application number 10/927667 was filed with the patent office on 2006-03-02 for scroll fluid machine.
Invention is credited to Tamotsu Fujioka, Ken Yanagisawa.
Application Number | 20060045783 10/927667 |
Document ID | / |
Family ID | 35943418 |
Filed Date | 2006-03-02 |
United States Patent
Application |
20060045783 |
Kind Code |
A1 |
Yanagisawa; Ken ; et
al. |
March 2, 2006 |
SCROLL FLUID MACHINE
Abstract
A scroll fluid machine comprises a stationary scroll and an
orbiting scroll fitted on an eccentric portion of a driving shaft.
The stationary scroll has a stationary end plate from which inner
and outer stationary wraps project, and the orbiting scroll has an
orbiting end plate from which inner and outer orbiting wraps
project. Between the stationary and orbiting end plates, inner and
outer annular partition walls are provided. Inside the inner
partition wall, the inner stationary wrap is engaged with the inner
orbiting wrap to form an expanding region, and between the inner
and outer partition walls, the outer stationary wrap is engaged
with the outer orbiting wrap to form a compressing region. A bore
is formed through the orbiting end plate so that fluid expanded and
cooled in the expanding region flows from the expanding region to
rear surface of the orbiting end plate to cool the orbiting end
plate.
Inventors: |
Yanagisawa; Ken;
(Yokohama-shi, JP) ; Fujioka; Tamotsu;
(Yokohama-shi, JP) |
Correspondence
Address: |
FULWIDER PATTON
6060 CENTER DRIVE
10TH FLOOR
LOS ANGELES
CA
90045
US
|
Family ID: |
35943418 |
Appl. No.: |
10/927667 |
Filed: |
August 28, 2004 |
Current U.S.
Class: |
418/55.2 |
Current CPC
Class: |
F04C 29/04 20130101;
F04C 29/045 20130101; F04C 23/008 20130101; F01C 21/10 20130101;
F01C 11/002 20130101; F01C 1/0215 20130101 |
Class at
Publication: |
418/055.2 |
International
Class: |
F01C 1/02 20060101
F01C001/02; F04C 2/00 20060101 F04C002/00; F01C 1/063 20060101
F01C001/063 |
Claims
1. A scroll fluid machine comprising: a driving shaft having an
eccentric portion; a housing; a stationary scroll having a
stationary end plate from which an inner stationary wrap and an
outer stationary wrap project, said stationary end plate being part
of the housing; an orbiting scroll having an orbiting end plate
from which an inner orbiting wrap and an outer orbiting wrap
project, the orbiting scroll being fitted on the eccentric portion
of the driving shaft and driven by the driving shaft to revolve
eccentrically with respect to the stationary scroll; an inner
annular partition wall mounted to the stationary end plate, said
inner orbiting wrap being revolved by the driving shaft to engage
with said inner stationary wrap inside the inner partition wall to
form an expanding region; and an outer annular partition wall
mounted to the stationary end plate, said outer orbiting wrap being
revolved by the driving shaft to engage with said outer stationary
wrap between the inner and outer partition walls to form a
compressing region; a first outlet for discharging the first fluid
in the compressing region; a second outlet for discharging the
second fluid in the expanding region; a first inlet for introducing
first fluid which is formed at part radially outer than the first
outlet; a second inlet for introducing second fluid which is formed
at part radially inner than the second outlet; and a discharge bore
which is formed through the orbiting end plate so that the second
fluid expanded and cooled in the expanding region flows partially
through the discharge bore to a rear surface of the orbiting end
plate to cool the orbiting end plate.
2. (canceled)
3. (canceled)
4. A scroll fluid machine as claimed in claim 1 wherein a blocking
plate is mounted to a boss of the orbiting end plate whereby the
second fluid flows outwardly from the discharge bore for effective
cooling to the orbiting plate.
5. A scroll fluid machine as claimed in claim 1 wherein a wall of
the housing between the orbiting scroll and an electric motor for
driving the driving shaft has a hole so that the second fluid flows
to the electric motor to cool it.
6. A scroll fluid machine as claimed in claim 1 wherein the second
fluid flows through the second outlet from the expanding region to
a front of the stationary end plate to cool the stationary end
plate.
7. A scroll fluid machine as claimed in claim 1 wherein an
expanding cover is mounted to the orbiting end plate to surround a
boss of the orbiting end plate, the expanding cover having an
inward-projecting portion to form a narrower space between the
expanding cover and the boss, fluid from the discharge bore from
the expanding portion being depressurized and further cooled when
it passes through the narrower portion.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a scroll fluid machine
having compressing and expanding regions, and especially to a
scroll fluid machine connected to a fuel cell or used as an air
expanding cooler.
[0002] In a fuel cell, electrolytes are put between an anode and a
cathode. Hydrogen is fed as cell active material to the cathode.
Electrons are released to create hydrogen ions and pass through an
external circuit to the anode. Oxygen is fed to the anode and
receives electrons from the external circuit. Oxygen ions react
with hydrogen ions in the electrolytes to produce water. Thus,
electrons flow from the cathode to the anode, or electric currents
flows from the anode to the cathode.
[0003] Generally air that contains oxygen is fed to the anode, so
that there are not only water but also unreactive oxygen and
nitrogen which is main ingredient of air. To combine hydrogen with
oxygen is exothermic reaction, so that temperature elevates from
that of fed air. A gas that mainly contains nitrogen must be
discharged from the anode.
[0004] Air pressurized by a compressor is fed to the anode, and the
gas at the anode has higher pressure than atmospheric pressure. The
gas is discharged to air and lost without doing work. Thus, the gas
is fed to an expander to obtain energy retrieval. Hence, both
compressor and expander are preferably, provided in the fuel
cell.
[0005] U.S. Pat. No. 6,506,512 B1 to Mori et al. discloses a
compression regenerative machine for a fuel cell, comprising a
compressor and an expander in a single fluid machine. An orbiting
scroll of the scroll fluid machine has a scroll wrap in each side.
The scroll wrap in one side compresses sucked fluid, while the
other-side scroll wrap expands the fluid to do work.
[0006] However, in the compression regenerative machine, the scroll
wrap is provided on each side of the orbiting scroll to increase
the length of the scroll. The orbiting scroll has at the center a
bearing boss for supporting the orbiting scroll. So the scroll wrap
is wound at the position outer than the outer circumference of the
bearing boss to increase the external diameter of the scroll end
plate. The wrap is provided on each side of the orbiting scroll
thereby causing troublesome working.
SUMMARY OF THE INVENTION
[0007] In view of the disadvantages in the prior art, it is an
object of the invention to provide a scroll fluid machine having
both compressing and expanding regions, the machine having
small-size and light-weight, manufacturing cost being reduced.
[0008] It is another object of the invention to provide a scroll
fluid machine in which fluid fallen in temperature in an expanding
region is utilized to effectively cool the scroll fluid machine and
an electric motor for driving the scroll fluid machine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The above and other features and advantages of the present
invention will become more apparent from the following description
with respect to embodiments as shown in appended drawings
wherein:
[0010] FIG. 1 is a vertical sectional side view of the first
embodiment of a scroll fluid machine according to the present
invention;
[0011] FIG. 2 is a sectional view taken along the line II-II in
FIG. 1, from which an auxiliary crank shaft and bearings thereof
are removed;
[0012] FIG. 3 is a vertical sectional side view of the second
embodiment of a scroll fluid machine according to the present
invention;
[0013] FIG. 4 is a front view of an example of an orbiting scroll
cooling fin in the first embodiment;
[0014] FIG. 5 is a front view of another example of an orbiting
scroll cooling fin in the first embodiment;
[0015] FIG. 6 is a view seen from an arrow VI in FIG. 3, showing a
stationary scroll cooling fin in the second embodiment of the
present invention;
[0016] FIG. 7 is a front view of further example of a stationary
scroll cooling fin in the second embodiment;
[0017] FIG. 8 is a schematic view of a pipe line when the scroll
fluid machine in the second embodiment is used in a fuel cell;
[0018] FIG. 9 is a schematic view of a pipe line when the scroll
fluid machine in the first embodiment is used in an air expanding
cooler; and
[0019] FIG. 10 is a vertical sectional side view of the third
embodiment of a scroll fluid machine according to the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] FIGS. 1 and 2 illustrate the first embodiment of a scroll
fluid machine according to the present invention, comprising a
scroll portion 10 and an electric motor 20. A stationary end plate
1' of a stationary scroll 1 has an inner annular partition wall
101; an outer annular partition wall 102; an outer stationary wrap
1a between the inner and outer partition walls 101 and 102; and an
inner stationary wrap 1b inside the inner partition wall 101. An
orbiting end plate 2' of an orbiting scroll 2 has an outer orbiting
wrap 2a that engages with the outer stationary wrap 1a; and an
inner orbiting wrap 2b that engages with the inner stationary wrap
1b. The orbiting scroll 2 is covered with a housing 3 fixed to the
stationary scroll 1. An electric motor 20 is fixed to a wall 3' of
the housing 3 by a bolt 26: Journals 21a and 21b of a driving shaft
21 of the electric motor 20 are rotatably supported by the housing
3 and a rear cover 25 of the electric motor 20 by bearings 8 and 23
respectively so that an axis of the driving shaft 21 may coincide
with the center of the stationary scroll 1.
[0021] Three bosses 5 protrude near the outer periphery of the
orbiting scroll 2 like an equilateral triangle, and a pin 7a at one
end of an auxiliary crank 7 is rotatably supported in each of the
bosses 5 via a bearing 9a. There are provided three bosses 6 on the
stationary scroll 1 and a pin 7b at the other end of the stationary
scroll 1 in each of the bosses 6 via a bearing 9b. The pins 7a, 7b
are provided eccentrically by a certain amount. An eccentric
portion 21 is formed at one end of the driving shaft 21 and
supports a boss 4 at the center of the rear surface of the orbiting
end plate 2' via a bearing 22. The eccentric portion 21c has the
same eccentricity as that of the pins 7a,7b of the auxiliary crank
7. Owing to such structure, when the driving shaft 21 is rotated,
the orbiting scroll 2 is revolved around the axis of the driving
shaft 21. The revolution mechanism may be a known means such as
Oldham coupling. As shown in FIG. 2, with respect to a spiral
direction of the scroll wrap, the inner scroll wraps are wound in a
counterclockwise direction from the center, and the outer scroll
wraps are wound in a clockwise direction from the annular wall.
[0022] Numeral 24 denotes a seal, and 27,28 denote elastic rings.
When an inner ball of the bearing is loosened from the eccentric
portion 21c so as to facilitate the eccentric portion 21c to insert
into the bearing 8 of the orbiting scroll, the elastic rings 27,28
prevent fretting corrosion owing to rotation of the inner surface
of the inner ball of the bearing on the outer circumference of the
pin portion 21c.
[0023] For example, when the elastic ring 27 made of hard rubber is
fitted in a bore of the eccentric portion 21c, the elastic ring 27
prevents the inner ball from rotating on the eccentric portion 21c
owing to friction after fitting of the inner ball while resistance
is small during fitting of the inner ball. Similarly, the elastic
ring 28 facilitates the pin portion 7a of the auxiliary crank 7 to
insert into the bearing 9a of the orbiting scroll 2 and prevents
the inner ball of the bearing 9a from sliding.
[0024] On the end plate 1' of the stationary scroll 1, there are a
compressing portion inlet 11 inside the outer partition wall 102; a
compressing portion outlet 12 outside the inner partition wall 101;
an expanding portion outlet 14 inside the inner partition wall 101;
and an expanding portion inlet 13 at the center. Pipes
11a,12a,14a,13a are connected to the holes 11,12,14,13
respectively. When the electric motor 20 is rotated in a
counterclockwise direction seen from the right in FIG. 1, the
orbiting scroll 2 is revolved in the counterclockwise direction
around the center of the stationary scroll 1 as shown in FIG. 2
while the orbiting scroll 2 is prevented from rotation around its
own axis. Thus, a compressing region is created between the inner
and outer partition walls 101 and 102, and an expanding region is
created inside the inner partition wall 101.
[0025] Fluid is sucked through the inlet 11, compressed in the
compressing region by engagement of the outer scroll wraps 1a and
2a between the inner and outer partition walls 101 and 102 and
discharged through the outlet 12. Fluid is sucked through the inlet
13, expanded in the expanding region by engagement of the inner
scroll wraps 1b and 2b inside the inner partition wall 101 and
discharged through the outlet 13.
[0026] The orbiting scroll end plate 2' has an expanded fluid
discharge bore 103 communicating with the expanding region, and an
blocking plate 106 is provided behind the orbiting scroll end plate
2'. The blocking plate 106 is fixed to the orbiting scroll end
plate 2' by bonding it to a cooling fin 105 and other means. The
fluid expanded in the expanding region is discharged not only
through the outlet 14 of the stationary scroll end plate 1' but
also through the discharge bore 103 of the orbiting scroll end
plate 2'. The expanded fluid discharged through the discharge bore
103 passes between the rear surface of the orbiting scroll 2 and
the blocking plate 106 toward the outer circumference to cool the
orbiting scroll 2, turns at the outer circumference of the blocking
plate 106, flows between the blocking plate 106 and the wall plate
3' of the housing 3 toward the center and flows into the electric
motor 20 through a bore 104 of the wall plate 3' of the housing 3.
The fluid that cools the electric motor 20 is discharged to the
outside through the outlet 107.
[0027] If the expanded fluid does not cool the electric motor 20,
the fluid may be discharged through an outlet of the housing 3
without the blocking plate 106 or bore 104 of the wall plate 3'.
The compressing region is partitioned by the outer partition wall
102 to prevent the fluid from flowing out of the compressing region
to the back of the orbiting scroll 2.
[0028] The inlet and outlet of fluid in the compressing region and
the inlet and outlet of fluid in the expanding region are all
formed on the front face of the stationary scroll, thereby avoiding
conduits which project on the outer circumference of the housing 3
and preventing the external diameter of the scroll machine 10 from
becoming larger owing to the conduits. It is advantageous in
providing the scroll fluid machine in a motor vehicle where space
is limited.
[0029] In FIGS. 1 and 2, the inlets and outlets are circular, but
may be other shapes by which required sectional area is obtainable,
The inlets and outlets on the front face of the stationary scroll
end plate allow the external diameter of the scroll fluid machine
to become smaller and allows conduits to be ordered clearly,
thereby providing good appearance.
[0030] The cooling fin behind the orbiting scroll end plate 2' may
be various shapes. FIG. 4 is a rear view of the orbiting scroll 2
and one example of the shape of the cooling fin. The fluid fallen
in temperature in the expanding region is discharged through the
discharge bore 103 of the orbiting scroll 2 and flows along the
cooling fin 105 to cool the orbiting scroll 2.
[0031] When the scroll fluid machine is used for a fuel cell, a gas
discharged from the fuel cell and sucked through the inlet 13 has
raised temperature with reaction heat in the fuel cell, but the gas
discharged from the outlet 103 has fallen temperature with
expansion in the expanding region and can be used as cooling
fluid,
[0032] FIG. 5 illustrates another embodiment of a cooling fin in an
orbiting scroll. In this embodiment, the cooling fin 105' is
spiral, and fluid through a discharge bore 103 flows through a
spiral path made by the cooling fin to cool an orbiting scroll and
flow out of an outlet 108 of the spiral path. The cooling fin also
reinforces the orbiting scroll.
[0033] FIG. 3 shows an embodiment similar to that in FIG. 1 except
that a cooling fin 111 and a front blocking plate 112 are provided
in front of a stationary scroll end plate 1' so that fluid
discharged through an outlet 14 from an expanding region flows
along the cooling fin between the front blocking plate and the
stationary scroll end plate. The same structure is omitted.
[0034] In FIG. 3, the cooling fin 111 is provided in front of the
stationary scroll end plate 1' and the front blocking plate 112 is
contacted with the top surface of the cooling fin 111. The front
blocking plate 11 may be bonded to the cooling fin 111 by adhesive
or may be fixed to the stationary scroll end plate 1' by a screw.
Between pipes 11a,12a,13a and bores through which the pipes pass in
the front blocking plate 112, a gap is not formed by a rubber
grommet to prevent fluid from leaking not to decrease cooling
efficiency.
[0035] The stationary scroll cooling fin may be various shapes.
FIG. 6 is a view seen from an arrow VI in FIG. 3 and shows one
example of the front shape of the cooling fin. Fluid fallen in
temperature in the expanding region is discharged through the
outlet 14 and flows along a radial cooling fin 111. After cooling
the stationary scroll, it is discharged to the outside.
[0036] When the scroll fluid machine is used for a fuel cell, a gas
discharged from the fuel cell and sucked into the expanding region
through an inlet 13 is raised in temperature owing to reaction heat
in the fuel cell, but is fallen with expansion in the expanding
region of the scroll fluid machine. It can be used as cooling
fluid.
[0037] FIG. 7 illustrates further example of a front shape of a
cooling fin of a stationary scroll. In the example, the cooling fin
111' is spiral and fluid discharged though an outlet 14 passes
through a spiral path formed by the cooling fin 111' to an outlet
112 of the spiral path 112.
[0038] When the scroll fluid machine is used in an air expanding
cooler, air that cools the stationary scroll and comes to the
outlet 112 of the spiral path can be fallen to very low
temperature, so that air discharged though the outlet 112 can be
employed as cooling air.
[0039] FIG. 8 schematically illustrates a pipe line in which the
scroll fluid machine in FIG. 3 is used in a fuel cell. Air cleaned
through an air filter 31 is sucked into the scroll fluid machine 10
through a pipe 11a, compressed in the compressing region and
transferred under pressure to an anode of a fuel cell 32 through a
pipe 12a. The air is cooled on the way of transfer, if necessary. A
gas from the fuel cell 32 is sucked into the center of the scroll
through a pipe 13, expanded in the expanding region of the scroll
fluid machine 10 and discharged from a pipe 14a.
[0040] As mentioned above, a gas sucked into the expanding region
from the fuel cell 32 is expanded in the expanding region to apply
rotational force to the orbiting scroll to help compression in the
compressing region, so that compression in the compressing region
is partially retrieved. The discharged gas fallen in temperature
with expansion in the expanding region is partially discharged
through the outlet 14 to cool the stationary scroll and discharged
to the outside. The remainder of the gas flows out of the discharge
bore 103 of the orbiting scroll to the back of the orbiting scroll
end plate 2'. After cooling the orbiting scroll, it flows into the
electric motor 20 through the bore 104 of the housing and is
discharged to the outside through the outlet 107. The scroll fluid
machine in FIG. 1 can be applied to a fuel cell.
[0041] FIG. 9 schematically illustrates a pipe line when the scroll
fluid machine in FIG. 1 is used in an air expanding cooler. Instead
of the fuel cell in FIG. 8, an air cooler 33 is disposed. Air
compressed in the compressing region of the scroll fluid machine 10
is introduced into the air cooler 33 and cooled by heat exchange
with cooling medium. The cooled air is introduced into the
expanding region of the scroll fluid machine 10. As a result of
working of the air to the orbiting scroll, expanded air discharged
through the pipe 14a from the outlet 14 has lower temperature than
air sucked through the air filter 31, and is used as cooler.
[0042] Air expanded in the expanding region partially flows through
the discharge bore 103 to the back of the orbiting scroll. After
cooling the orbiting scroll, it is introduced into the electric
motor 20 and discharged to the outside through the outlet 107 after
cooling to the electric motor. The scroll fluid machine in FIG. 3
is also applied to an air-expanding cooler.
[0043] FIG. 10 illustrates the third embodiment of a scroll fluid
machine according to the present invention, in which an expanding
cover 120 is mounted to the rear surface of an orbiting end plate
2' to surround a boss 4. Fluid already expanded in an expanding
region between an inner stationary wrap 1b and an inner orbiting
wrap 2b flows through a discharge bore 103 and an annular bore 122
of an annular support plate 121 for supporting the expanding cover
120. The fluid passes through a narrower space 124 between an
inward-projecting portion 123 and the boss 4. In the narrower space
124, the fluid becomes faster and gives lower pressure to become
lower temperature. A central bearing 125 driven by a driving shaft
21 is likely to heat and to wear owing to friction. By the
lower-temperature fluid that passes near the central bearing 125,
the central bearing 125 is cooled, so that durability is increased.
Thereafter, the fluid flows through a bore 104 to an electric motor
20 to cool it and to the rear surface of the orbiting end plate 2'
to cool it.
[0044] The foregoing merely relates to embodiments of the
invention. Various changes and modifications may be made by a
person skilled in the art without departing from the scope of
claims wherein:
* * * * *