U.S. patent application number 11/307082 was filed with the patent office on 2006-09-07 for scroll fluid machine.
This patent application is currently assigned to ANEST IWATA CORPORATION. Invention is credited to Tamotsu Fujioka, Atsushi Unami.
Application Number | 20060198746 11/307082 |
Document ID | / |
Family ID | 36143180 |
Filed Date | 2006-09-07 |
United States Patent
Application |
20060198746 |
Kind Code |
A1 |
Fujioka; Tamotsu ; et
al. |
September 7, 2006 |
SCROLL FLUID MACHINE
Abstract
A scroll fluid machine comprises a stationary scroll fixed to a
housing and an orbiting scroll that turns with a driving shaft. The
stationary scroll comprises a stationary end plate having inner and
outer stationary wraps and the orbiting scroll comprises an
orbiting end plate having inner and outer orbiting wraps. Rotation
of the orbiting scroll allows the inner and outer stationary wraps
to engage with the inner and outer orbiting wraps respectively to
form inner and outer volume-variable chambers. The two chambers
have substantially the same compression ratio, so that
substantially-equal low pressure gases are produced.
Inventors: |
Fujioka; Tamotsu;
(Yokohama-shi, Kanagawa, JP) ; Unami; Atsushi;
(Yokohama-shi, Kanagawa, JP) |
Correspondence
Address: |
ZARLEY LAW FIRM P.L.C.
CAPITAL SQUARE
400 LOCUST, SUITE 200
DES MOINES
IA
50309-2350
US
|
Assignee: |
ANEST IWATA CORPORATION
3176, Shinyoshida-cho Kohoku-ku
Yokohama-shi
JP
|
Family ID: |
36143180 |
Appl. No.: |
11/307082 |
Filed: |
January 23, 2006 |
Current U.S.
Class: |
418/55.1 ;
418/55.2 |
Current CPC
Class: |
F04C 18/0215 20130101;
F04C 29/12 20130101; F04C 23/001 20130101 |
Class at
Publication: |
418/055.1 ;
418/055.2 |
International
Class: |
F01C 1/02 20060101
F01C001/02; F04C 2/00 20060101 F04C002/00; F01C 1/063 20060101
F01C001/063 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 2, 2005 |
JP |
2005-25766 |
Jan 6, 2006 |
JP |
2006-1669 |
Claims
1. A scroll fluid machine comprising: a housing; a driving shaft
having an eccentric axial portion; a stationary scroll fixed to and
in the housing and having an inner stationary wrap and an outer
stationary wrap on an stationary end plate; and an orbiting scroll
having an inner orbiting wrap and an outer orbiting wrap on an
orbiting end plate, the orbiting scroll being revolved with the
eccentric axial portion of the driving shaft with respect to the
stationary scroll to allow the inner stationary wrap to engage with
the inner orbiting wrap to form an inner volume-variable chamber
within the inner stationary wrap and to allow the outer stationary
wrap to engage with the outer orbiting wrap to form an outer
volume-variable chamber between the inner and outer stationary
wraps, the stationary end plate having an outer intake port at a
circumference and an outer discharge port radially far from the
circumference within the outer volume variable chamber and having
an inner intake port radially far from a center and an inner
discharge port at the center in the inner volume-variable chamber,
the inner volume-variable chamber having substantially the same
compression ratio as that of the outer volume-variable chamber, a
gas introduced from the outer intake port being compressed in the
outer volume-variable chamber with revolution of the orbiting
scroll and discharged from the outer discharge port, a gas
introduced from the inner intake port being compressed in the inner
volume-variable chamber with the revolution of the orbiting scroll
and discharged from the inner discharge port under substantially
the same low-pressure as what is discharged from the outer
discharge port.
2. A scroll fluid machine as claimed in claim 1 wherein the outer
volume-variable chamber comprises an outer beginning-end
volume-variable chamber communicating with the outer intake port
and an outer terminating-end volume-variable chamber communicating
with the outer discharger port, the inner volume-variable chamber
comprising an inner beginning-end volume-variable chamber
communicating with the inner intake port and an inner
terminating-end volume-variable chamber communicating with the
inner discharger port, a volume ratio of the outer terminating-end
volume-variable chamber to the outer beginning-end volume-variable
chamber being substantially equal to that of the inner
terminating-end volume variable chamber to the inner beginning-end
volume-variable chamber.
3. A scroll fluid machine as claimed in claim I wherein the outer
discharge port of the outer volume-variable chamber is connected to
the inner intake port of the inner volume-variable chamber.
4. A scroll fluid machine as claimed in claim 1 wherein the scroll
fluid machine is a scroll compressor.
5. A scroll fluid machine comprising: a housing; a driving shaft
having an eccentric axial portion; a stationary scroll fixed to and
in the housing and having an inner stationary wrap and an outer
stationary wrap on an stationary end plate; and an orbiting scroll
having an inner orbiting wrap and an outer orbiting wrap on an
orbiting end plate, the orbiting scroll being revolved with the
eccentric axial portion of the driving shaft with respect to the
stationary scroll to allow the inner stationary wrap to engage with
the inner orbiting wrap to form an inner volume-variable chamber
within the inner stationary wrap and to allow the outer stationary
wrap to engage with the outer orbiting wrap to form an outer
volume-variable chamber between the inner and outer stationary
wraps, the stationary end plate having an outer intake port
radially inward far from a circumference and an outer discharge
port at the circumference within the outer volume variable chamber
and having an inner intake port at the center and an inner
discharge port radially far from a center in the inner
volume-variable chamber, the inner volume-variable chamber having
substantially the same compression ratio as that of the outer
volume-variable chamber, a gas introduced from the inner intake
port being decompressed in the outer volume-variable chamber with
revolution of the orbiting scroll and discharged from the outer
discharge port, a gas introduced from the outer intake port being
decompressed in the inner volume-variable chamber with the
revolution of the orbiting scroll and discharged from the outer
discharge port under substantially the same low-pressure as what is
discharged from the inner discharge port.
6. A scroll fluid machine as claimed in claim 5 wherein the outer
volume-variable chamber comprises an outer beginning-end
volume-variable chamber communicating with the outer intake port
and an outer terminating-end volume-variable chamber communicating
with the outer discharge port, the inner volume-variable chamber
comprising an inner beginning-end volume-variable chamber
communicating with the inner intake port and an inner
terminating-end volume-variable chamber communicating with the
inner discharger port, a volume ratio of the outer terminating-end
volume-variable chamber to the outer beginning-end volume-variable
chamber being substantially equal to that of the inner
terminating-end volume variable chamber to the inner beginning-end
volume-variable chamber.
7. A scroll fluid machine as claimed in claim 5 wherein the inner
discharge port of the inner volume-variable chamber is connected to
the outer intake port of the outer volume-variable chamber.
8. A scroll fluid machine as claimed in claim 5 wherein the scroll
fluid machine is a scroll decompressor.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a scroll fluid machine by
which a high volume of gases are produced under relatively low
pressure.
[0002] In a scroll fluid machine including a scroll compressor and
a scroll decompressor, volume of a sealed chamber is gradually
reduced from the beginning end of a wrap winding at the
circumference to the terminating end near the center, so that a gas
sucked from the circumference is compressed and discharged near the
center or a gas sucked from the center is decompressed and
discharged from the circumference.
[0003] Such a known scroll fluid machine is used for middle or high
pressure to make relatively high-pressure compressed gas or achieve
effective decompressing.
[0004] However, in the scroll fluid machine, to transport powders
such as flour, it is impossible to obtain a high volume of
compressed gases under low pressure such as about 0.2 to 0.3 MPa.
To obtain a high volume of compressed gases under such low
pressure, it is necessary to expand spaces between wraps and to
reduce the number of windings.
[0005] Expanded spaces between the wraps make a radius of a
revolving orbiting scroll larger to increase an external diameter
of the orbiting scroll. So it is necessary for the heavy orbiting
scroll to revolve with a larger diameter. Load adapted to a support
for an orbiting shaft of the orbiting scroll increases to make it
necessary to provide a high load-resistant bearing thereby
resulting in increase in weight and size requiring high
manufacturing cost.
[0006] To avoid such problems, the wraps must be made as close as
possible to the center of the orbiting scroll not to increase a
diameter of the orbiting scroll. But it involves high discharge
pressure to make it impossible to obtain a desired low-pressure
compressed gas.
[0007] Thus, conventionally, in a scroll compressor for low
pressure, an orbiting wrap is partially removed near the center of
an orbiting scroll and large-spaced wraps are provided only in
parts remote from the center. However, the center of the orbiting
scroll does not play a role of output, which is inefficient and
uneconomical.
SUMMARY OF THE INVENTION
[0008] In view of the disadvantages in the prior art, it is an
object of the present invention to provide a scroll fluid machine
in which a space between wraps is the same as a known middle or
high pressure machine, wraps--being provided to produce a
low-pressure compressed gas almost equal to a compressed gas in the
circumference to make it possible to obtain a high volume of
low-pressure gases without change in the whole size or the number
of revolutions of the scroll.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The features and advantages of the invention will become
more apparent from the following description with respect to
embodiments as shown in accompanying drawings wherein:
[0010] FIG. 1 is a vertical sectional view of one embodiment of a
scroll fluid machine according to the present invention;
[0011] FIG. 2 is a vertical sectional view taken along the line
II-II in FIG. 1;
[0012] FIG. 3 is a vertical sectional view similar to FIG. 2 and
showing that engagement of wraps varies; and
[0013] FIG. 4 is a vertical sectional view similar to FIG. 2 and
showing another embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0014] FIG. 1 is a vertical sectional side view of a scroll
compressor as one embodiment of the present invention. In this
invention, there are outer and inner volume-variable chambers
defined by stationary and orbiting wraps.
[0015] The scroll compressor in FIG. 1 is basically similar to a
known device and will be simply described. In FIG. 1, left and
rights sides are deemed front and rear respectively.
[0016] In the front or left side in FIG. 1, an outer intake port 3a
is formed on the circumference of a stationary end plate 2 of a
stationary scroll 1, and an inner discharge port 4b is formed at
the center. Between them, an outer discharge port 4a and an inner
intake port 3b are formed.
[0017] A spiral stationary wrap 5 is provided on the rear surface
of the stationary end plate 2. On the front surface, there are a
plurality of horizontal equal-height gently-corrugated cooling fins
6 equally spaced. An orbiting scroll 7 behind the stationary scroll
1 has a spiral orbiting wrap 9 on the front surface of a circular
orbiting end plate 3 or opposing surface to the stationary scroll
1, and a plurality of horizontal equal-height corrugated cooling
fins 10 equally spaced on the rear surface.
[0018] On the rear surface of the orbiting scroll 7, a bearing
plate 11 is mounted. At the center of the rear surface of the
bearing plate 11, there is a tubular boss 15 pivotally supporting
an eccentric axial portion 13 of a driving shaft 12 via a bearing
14.
[0019] At three points of the circumference on the rear surface of
the bearing plate 11, there is a known crank-pin-type self-rotation
preventing device 16, so that the orbiting scroll 7 is
eccentrically revolved around the driving shaft 12 with respect to
a housing 17.
[0020] A cover plate 18 is fixed to the front surface of the
stationary scroll 1 with a screw 19. The orbiting scroll 7 is fixed
to the bearing plate 11 with a screw 20. A rear portion 21 of the
stationary scroll 1 is fixed to the housing 17 with a bolt 22 and a
nut 23.
[0021] Engagement grooves 24,25 are formed on the tip ends of the
stationary and orbiting wraps 5,9 respectively. Sealing members "S"
are fitted in the engagement grooves 24,25 in sliding contact
between the orbiting end plate 8 of the orbiting scroll 7 and the
stationary end plate 4 of the stationary scroll 1.
[0022] As shown in FIGS. 2 and 3 sectioned along the line II-II in
FIG. 1, the stationary wrap 5 is separated to an outer
volume-variable chamber stationary wrap 5a communicating with the
outer intake port 3a and an inner volume-variable chamber
stationary wrap 5b communicating with the inner discharge port 4b,
while the orbiting wrap 9 is separated to an outer volume-variable
chamber orbiting wrap 9a and an inner volume-variable chamber
orbiting wrap 9b.
[0023] A gap between the outer volume-variable chamber stationary
wrap 5a and the outer volume-variable chamber orbiting wrap 9a is
large, and a gap between the inner volume-variable chamber
stationary wrap 5b and the inner volume-variable chamber orbiting
wrap 9b is somewhat small.
[0024] A volume ratio of an outer beginning-end volume-variable
chamber "B" communicating with the outer discharger port 4a to an
outer terminating-end volume-variable chamber "A" communicating
with the outer intake port 3a is substantially the same as a volume
ratio of an inner terminating-end volume-variable chamber "D"
communicating with the inner discharge port 4b to an inner
beginning-end volume-variable chamber "C" communicating with the
inner intake port 3b.
[0025] Accordingly, compressed gases having almost equal pressure
are produced in the outer and inner volume-variable chambers, so
that a large quantity of low-pressure compressed gas is obtained
compared with a conventional device in which a central wrap is
removed in a scroll.
[0026] FIG. 4 is a vertical sectional side view of a scroll
decompressor according to the present invention and similar to FIG.
2.
[0027] In FIG. 4, the inner discharge port 4b in FIG. 2 is changed
to an inner intake port 3b and the outer discharge port 4a is
changed to an outer intake port 3a. Similarly, the inner intake
port 3b is changed to an inner discharge port 4b, and the outer
intake port 3a is changed to an outer discharge port 4a. The others
are the same as those in FIGS. 1 to 3. In FIG. 4, a gas sucked from
the inner intake port 3b is decompressed and discharged from the
outer discharge port 4a.
[0028] The foregoing merely relates to embodiments of the present
invention. Various changes and modifications may be made by a
person skilled in the art without departing from the scope of
claims wherein.
* * * * *