U.S. patent application number 10/162582 was filed with the patent office on 2002-10-17 for scroll compressor and scroll-type pressure transformer.
Invention is credited to Takahashi, Mineo.
Application Number | 20020150491 10/162582 |
Document ID | / |
Family ID | 27343145 |
Filed Date | 2002-10-17 |
United States Patent
Application |
20020150491 |
Kind Code |
A1 |
Takahashi, Mineo |
October 17, 2002 |
Scroll compressor and scroll-type pressure transformer
Abstract
A scroll compressor comprises a stationary scroll 122 fixed to a
casing 121, a stator 123 fixed to the casing 121, bearing supports
126 and 127 fixed to the casing 121, a rotary shaft 125 rotatably
supported by the bearing supports 126 and 127 through bearings 128
and 129, a rotor 124 fixed to the rotary shaft 125, a hollow
orbiting shaft 130 eccentrically and rotatably supported by the
rotary shaft 125, a mounting member 133 fixed within the hollow
orbiting shaft 130, an orbiting scroll 135 mounted to a mounting
portion 134 of the mounting member 133, a hollow orbiting plate 136
fixed to the lower portion of the hollow orbiting shaft 130, an
Oldham's ring 137 provided between the bearing support 127 and a
hollow orbiting plate 136 and having protrusions 138 and 139,
grooves 140 and 141 formed on the bearing support 127 and the
hollow orbiting plate 136, the protrusions 138 and 139 being
engaged with the grooves 140 and 141, and a suction pipe 142 and a
discharge pipe 143 connected to the stationary scroll 122.
Inventors: |
Takahashi, Mineo;
(Yachiyo-shi, JP) |
Correspondence
Address: |
JACOBSON HOLMAN PLLC
400 SEVENTH STREET N.W.
SUITE 600
WASHINGTON
DC
20004
US
|
Family ID: |
27343145 |
Appl. No.: |
10/162582 |
Filed: |
June 6, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10162582 |
Jun 6, 2002 |
|
|
|
09835497 |
Apr 17, 2001 |
|
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Current U.S.
Class: |
418/55.2 ;
418/55.3 |
Current CPC
Class: |
F04C 23/001 20130101;
F04C 18/0223 20130101; F04C 29/0085 20130101 |
Class at
Publication: |
418/55.2 ;
418/55.3 |
International
Class: |
F01C 001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 19, 2000 |
JP |
2000-118467 |
Apr 25, 2000 |
JP |
2000-123920 |
Jul 10, 2000 |
JP |
2000-208326 |
Claims
We claim:
1. A scroll compressor comprises; a casing; a stationary scroll
fixed to said casing; a stator fixed to said casing; a rotary shaft
rotatably supported by said casing; a rotor fixed to said rotary
shaft; an orbiting shaft eccentrically and rotatably supported by
said rotary shaft; an orbiting scroll fixed to said orbiting shaft,
and an anti-self-rotation device having a stationary portion fixed
to said casing and a movable portion engaged with said orbiting
shaft.
2. A scroll compressor comprising: a fixed body; a stationary
scroll fixed to said fixed body, said stationary scroll being a
part of a compressor body; a rotary shaft rotatably supported by
said fixed body; a driving device for rotatably driving said rotary
shaft; a hollow orbiting shaft eccentrically and rotatably
supported by said rotary shaft; an anti-self-rotation device for
preventing the self-rotation of said hollow orbiting shaft; and an
orbiting scroll fixed to said hollow orbiting shaft, said orbiting
scroll being a part of said compressor body, wherein said
compressor body is located inside said hollow orbiting shaft.
3. A scroll compressor comprises: a casing; a stationary scroll
fixed to said casing, said stationary scroll being a part of a
compressor body; a stator fixed to said casing; a rotary shaft
rotatably supported by said casing; a rotor fixed to said rotary
shaft; an orbiting shaft eccentrically and rotatably supported by
said rotary shaft; an anti-self-rotation device for preventing the
self-rotation of said orbiting shaft; and an orbiting scroll fixed
to said orbiting shaft, said orbiting scroll being a part of said
compressor body, wherein said compressor body is located inside
said rotor.
4. A scroll compressor as defined in claim 3, wherein said orbiting
shaft is a hollow orbiting shaft, wherein said orbiting scroll is
mounted on a mounting member fixed within said hollow orbiting
shaft.
5. A scroll compressor as defined in claim 3, wherein said rotor is
fixed to said rotary shaft through a coupling member.
6. A scroll-type pressure transformer comprising; a casing; a motor
supported by said casing through a first bearing and provided with
a rotary shaft having an eccentric hollow portion; an orbiting
shaft penetrating said hollow portion of said rotary shaft and
rotatably supported by said rotary shaft through a second bearing;
an orbiting scroll member fastened to said orbiting shaft and
having scrolls on both sides of said orbiting scroll member; a pair
of stationary scroll members fixed to said casing and opposed to
each scroll of said orbiting scroll member; an anti-self-rotation
device provided in said orbiting shaft; a gas inlet port
communicating with a low-pressure area of a pair of scroll spaces
formed between said orbiting scroll member and said stationary
scroll members on both sides of said orbiting scroll member, and a
gas discharge port communicating with a high-pressure area of said
scroll spaces.
7. A scroll-type pressure transformer as defined in claim 6,
wherein said anti-self-rotation device is provided between said
orbiting plate fixed to said orbiting shaft and said casing.
8. A scroll-type pressure transformer as defined in claim 6 or 7,
wherein said orbiting scroll member is fastened to said orbiting
shaft slidably in the axial direction of said orbiting shaft.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a scroll compressor used as
air compressors, vacuum pumps, refrigerant gas compressors, and
oxygen compressors. Further, the present invention relates to a
scroll compressor used as a pressure transformer, namely, a
scroll-type pressure transformer capable of compressing or reducing
pressure of gas or air.
BACKGROUND OF THE INVENTION
[0002] FIG. 6 is a schematic sectional view showing a conventional
scroll compressor as described in Japanese Patent Laid-Open
Publication No. Sho 57-24486. Referring to FIG. 6, this compressor
includes a bearing support 2 fixed to a casing 1, and a stationary
scroll 3 fixed to the bearing support 2 and formed with a spiral
lap. The compressor further includes a stator 4 fixed to the casing
1, a rotary shaft 6 supported rotatably by the bearing support 2
and the casing 1 through bearings 7 and 8, a rotor 5 fixed to the
rotary shaft 6, and an orbiting shaft 9 supported orbitally by the
rotary shaft 6 through bearings 10 and 11. Respective axes of the
rotary shaft 6 and the orbiting shaft 9 are eccentrically arranged.
The orbiting shaft 9 is provided integrally with an orbiting scroll
12 having a lap formed in the same configuration as that of the
stationary scroll 3. These laps of the orbiting scroll 12 and the
stationary scroll 3 are overlappedly engaged with each other to
form a plurality of compression chambers. An Oldham's ring is
provided between the orbiting scroll 12 and the bearing support 2
as an anti-self-rotation device 13 for preventing the self-rotation
of the orbiting scroll 12. A suction pipe 14 is connected to the
casing 1, and a discharge pipe 15 is connected to the stationary
scroll 3.
[0003] In this scroll compressor, when a winding of the stator 4 is
energized, the rotor 5 and the rotary shaft 6 are rotated and the
orbiting shaft 9 are eccentrically orbited about the axis of the
rotary shaft 6. However, the anti-self-rotation device 13 prevents
the self-rotation of the orbiting shaft 9. Thus, the orbiting
scroll 12 is orbited eccentrically to the stationary scroll 3
without any self-rotation of the orbiting scroll 12 and thereby the
volume of the compression chambers formed between the orbiting
scroll 12 and the stationary scroll 3 is gradually reduced. Then, a
gas to be compressed, such as refrigerant gas, is sucked from the
suction pipe 14, and introduced in the outboard side of the
compression chambers through a vent hole (not shown) provided in
the bearing support 2, whereafter the gas is compressed in the
compression chambers, and discharged from the discharge pipe
15.
[0004] However, in such a scroll compressor, the anti-self-rotation
device 13 is provided between the orbiting scroll 12 and the
bearing support 2. Thus, the anti-self-rotation device 13 is
increased in temperature with temperature raise of the orbiting
scroll 12, resulting in shortened life of the anti-self-rotation
device 13. Further, the thermal expansion of the anti-self-rotation
device 13 leads to degraded efficiency of the scroll
compressor.
[0005] In addition, such a scroll compressor has a problem to be
improved in that it disadvantageously has a large dimension in the
axial direction of the rotary shaft 6, i.e., in the longitudinal
direction of the sheet of FIG. 6.
[0006] Further, there have been known scroll compressors using a
mechanism wherein a scroll space between a stationary scroll and an
orbiting scroll is gradually reduced by orbiting the orbiting
scroll to the stationary scroll so as to compress the gas in the
scroll space. Such scroll compressors are currently used for
various purposes, such as a compressor for air conditioners, due to
their advantages of high compression efficiency and excellent
quietness. The above scroll compressors may serve as scroll vacuum
pumps with a substantially same structure. These scroll vacuum
pumps have the similar advantages as described above and thereby is
used for various vacuum apparatuses.
[0007] FIGS. 16 and 17 show a conventional scroll compressor having
such a structure. In this scroll compressor, when a rotary shaft
261 of a motor 260 is rotated, a crank 262a of a crankshaft 262
coupled to the motor by a joint 263 is eccentrically moved. Then,
an orbiting scroll member 280 rotatably attached to the crank 262a
is orbited without self-rotation by means of an anti-self-rotation
mechanism 290. Thus, a scroll space between a scroll of the
orbiting scroll member 280 and a scroll of stationary scroll
members 270a, 270b are reduced in volume and thereby a gas
introduced in the scroll space is compressed. The compressed gas is
then discharged from a discharge port 278 through a discharge
passage 271.
[0008] However, the above conventional scroll compressor has a
complexified structure because the orbiting scroll member 280 is
rotatably coupled to the crank 262a of the crankshaft 262 through a
bearing 283, and the self-rotation of the orbiting scroll member
280 is prevented by the anti-self-rotation mechanism 290 provided
between the orbiting scroll member 280 and the stationary scroll
member 270b. Further, the bearing 283 of the orbiting scroll member
280 is required to have a high precision for bearing the crank 262a
and a high strength proof against the deforming force caused by the
temperature difference in a partial portion of both scrolls.
Furthermore, the basic circle diameter of the scroll is increased
due to the orbiting mechanism with the bearing 283,and the
dimension of the orbiting scroll member 280 is inevitably increased
due to the structure with the anti-self-rotation mechanism. Thus,
it has been difficult to promote downsizing for the structure of
the conventional scroll compressors. Consequently, the conventional
scroll compressors results in a undesirably increased cost.
Further, due to the above particular structure of the
anti-self-rotation mechanism 290, it is difficult to adequately
lubricate, and the temperature of the anti-self-rotation mechanism
290 is increased with temperature rise of the orbiting scroll
member 280. This leads to a degraded compression efficiency
resulting from the deformation of the orbiting scroll member 280
caused by thermal expansion and vibration thereof, and to a
shortened life of the anti-self-rotation mechanism 290.
[0009] Such a scroll compressor typically has a structure wherein a
gas is compressed in a space formed by each scroll of the
stationary scroll members 270a and 270b and the orbiting scroll
member 280. Specifically, this scroll compressor comprises the
motor 260, the crankshaft 262 coupled to the rotary shaft 261 of
the motor through the joint 263, the pair of stationary scroll
members 270a and 270b, the orbiting scroll member having a pair of
scrolls on both sides thereof, the anti-self-rotation device 290,
and an inlet port 276 and the discharge port 278 mounted to the
stationary scroll members 270a and 270b. Spiral scrolls protrudes
integrally from both sides of a disk-shaped base plate 285 of the
orbiting scroll member 280, respectively. The volume of the space
(scroll space) between the scrolls of the orbiting scroll member
280 and the spiral scrolls protruding integrally from respective
inner surfaces of the stationary scroll members 270a and 270b are
gradually reduced by the orbiting of the orbiting scroll member
280.
[0010] At the center of tthe orbiting scroll member 280 is provided
with a cylindrical hub 281, and the crank 262a of the crankshaft
262 penetrates the cylindrical hub 281 through the bearing 283. The
innermost portion of the disk-shaped base plate 285 of the orbiting
scroll member 280 facing the high-pressure areas of the scroll
spaces is provided with a through hole 287 to communicate each
high-pressure area of both scroll spaces. A discharge passage 271
is formed in the one stationary scroll member 270b, and each
high-pressure area in both scroll spaces communicates with the
discharge port 278 through the discharge passage 271.
[0011] At the center of the stationary scroll member 270a is
provided with a through hole 273, and a rotary portion 262b of the
crankshaft 262 penetrates through the hole 273 through a bearing
274. Another through hole is also provided at the center of the
stationary scroll member 270b, and the rotary portion 262b of the
crankshaft 262 penetrates this through hole through a bearing.
[0012] The crank-type anti-self-rotation mechanism generally
comprises a pair (two) of a rotatable crank between the orbiting
scroll base plate and the casing. In this example, three rotatable
cranks are provided in order to enhance the balance of the orbiting
scroll base plate. Specifically, as shown in FIGS. 16 to 18, the
anti-self-rotation mechanism 290 comprises three bearings 292, 292
and 292 provided in the base plate 285 of the orbiting scroll
member 280, three bearings 294, 294 and 294 provided in the
stationary scroll member 270b, and a crank member 296 rotatably
supported by the bearings 292 and 294 adjacent to each other. The
three bearings 292, 292 and 292 provided in the orbiting scroll
member 280 are located at apexes of a first equilateral triangle
T1, respectively, and the three bearings 294, 294 and 294 provided
at the stationary scroll member 270b are located at apexes of a
second equilateral triangle T2 slightly out of alignment to the
first equilateral triangle T1 with the same size as the first
equilateral triangle T1. The center O1 of the first equilateral
triangle T1 lies at the center of the crank 262a of the crankshaft
262. The center O2 of the second equilateral triangle T2 lies at
the center of the rotary portion 262b of the crankshaft 262. By
virtue of this structure, the self-rotation of the orbiting scroll
member 280 is prevented when the orbiting scroll member 280 is
orbited with the radius r by the crankshaft 262.
[0013] The scroll compressor shown in FIGS. 16 to 18 may be used as
a scroll vacuum pump. However, in either applications for the
scroll compressor or the scroll vacuum pump, they inevitably
involve the problems of complex structure, high cost, and degraded
efficiency.
SUMMARY OF THE INVENTION
[0014] The present invention has been embodied to solve the above
problem. Thus, it is an object of the present invention to provide
a scroll compressor capable of achieving longer life of the
anti-self-rotation device and maintaining stable efficiency.
[0015] It is another object of the present invention to provide a
scroll compressor capable of reducing the dimension in the axial
direction of the rotary shaft.
[0016] It is still another object of the present invention to
provide a scroll-type pressure transformer capable of facilitating
downsizing with a simple structure, and achieving an excellent
pressure transforming efficiency.
[0017] According to one aspect of the present invention, there is
provided a scroll compressor comprises a casing, a stationary
scroll fixed to said casing, a stator fixed to said casing, a
rotary shaft rotatably supported by said casing, a rotor fixed to
said rotary shaft, an orbiting shaft eccentrically and rotatably
supported by said rotary shaft, an orbiting scroll fixed to said
orbiting shaft, and an anti-self-rotation device having a
stationary portion fixed to said casing and a movable portion
engaged with a certain portion of said orbiting shaft.
[0018] According to another aspect of the present invention, there
is provided a scroll compressor comprising a fixed body, a
stationary scroll which is a part of a compressor body and fixed to
said fixed body, a rotary shaft rotatably supported by said fixed
body, a driving device for rotatably driving said rotary shaft, a
hollow orbiting shaft eccentrically and rotatably supported by said
rotary shaft, an anti-self-rotation device for preventing the
self-rotation of said hollow orbiting shaft, and a hollow orbiting
scroll which is a part of said compressor body and fixed to said
hollow orbiting shaft, wherein said compressor body is located
inside said hollow orbiting shaft.
[0019] According to still another aspect of the present invention,
there is provided a scroll compressor comprises a casing, a
stationary scroll which is a part of a compressor body and fixed to
said casing, a stator fixed to said casing, a rotary shaft
rotatably supported by said casing, a rotor fixed to said rotary
shaft, an orbiting shaft eccentrically and rotatably supported by
said rotary shaft, an anti-self-rotation device for preventing the
self-rotation of said orbiting shaft, and an orbiting scroll which
is a part of said compressor body and fixed to said orbiting shaft,
wherein said compressor body is located inside said rotor.
[0020] In this case, a hollow orbiting shaft may be applied as said
orbiting shaft. Further, a mounting member may be fixed inside said
hollow orbiting shaft to mount said orbiting scroll on said
mounting member. Furthermore, said rotor may be fixed to said
rotary shaft through a coupling member.
[0021] As a result of a attentive research considering the above
problems, the inventors has discovered that the orbiting scroll
member may be orbited without its self-rotation by mounting an
orbiting shaft to a rotary shaft of a motor, and then attaching an
anti-self-rotation mechanism to an orbiting shaft and mounting it
between the orbiting plate and a casing, followed by fastening an
orbiting scroll to the orbiting shaft. Based on this knowledge, the
present invention has been completed.
[0022] According to further another aspect of the present
invention, a scroll-type pressure transformer comprises a casing, a
motor supported by said casing through a bearing and provided with
a rotary shaft having an eccentric hollow portion, an orbiting
shaft penetrating said hollow portion of said rotary shaft and
rotatably supported by said rotary shaft through a bearing, an
orbiting scroll member fastened to said orbiting shaft and having
scrolls on both sides of said orbiting scroll member, a pair of
stationary scroll members fixed to said casing and opposed to each
scroll of said orbiting scroll member, an anti-self-rotation device
provided in said orbiting shaft, a gas inlet port communicating
with a low-pressure area of a pair of scroll spaces formed between
said orbiting scroll member and said stationary scroll members on
both sides of said orbiting scroll member, and a gas discharge port
communicating with a high-pressure area of said scroll spaces.
[0023] Preferably, the orbiting scroll member is fastened to the
orbiting shaft slidably in the axial direction under various
operating conditions. It is also preferable that the
anti-self-rotation device is provided between the orbiting plate
fixed to the orbiting shaft and the casing. The scroll-type
pressure transformer according to the present invention may serve
as either of a scroll compressor and a scroll vacuum pump.
[0024] Other features and advantages of the present invention will
be apparent from the accompanying drawings and from the detailed
description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a schematic sectional view showing a scroll
compressor according to the first embodiment of the present
invention;
[0026] FIG. 2 is a sectional view taken along the line A-A of FIG.
1;
[0027] FIG. 3 is a schematic sectional view showing a scroll
compressor according to the second embodiment of the present
invention;
[0028] FIG. 4 is a schematic sectional view showing a scroll
compressor according to the third embodiment of the present
invention;
[0029] FIG. 5 is a sectional view taken along the line B-B of FIG.
4;
[0030] FIG. 6 is a schematic sectional view showing a conventional
scroll compressor.
[0031] FIG. 7 is a schematic sectional view showing a scroll
compressor according to the fourth embodiment of the present
invention;
[0032] FIG. 8 is a sectional view taken along the line C-C of FIG.
7;
[0033] FIG. 9 is a schematic sectional view showing a scroll
compressor according to the fifth embodiment of the present
invention;
[0034] FIG. 10 is a schematic sectional view showing a scroll
compressor according to the sixth embodiment of the present
invention;
[0035] FIG. 11 is a sectional view taken along the line D-D of FIG.
10;
[0036] FIG. 12 is a sectional view showing an overall structure of
one example of a scroll-type pressure transformer according to the
present invention;
[0037] FIG. 13 is a partially exploded view of a part of the
scroll-type pressure transformer of FIG. 12;
[0038] FIG. 14 is an exploded view of another portion of the
scroll-type pressure transformer of FIG. 12;
[0039] FIG. 15 is a sectional view showing an overall structure of
another example of a scroll-type pressure transformer according to
the present invention wherein an orbiting scroll member is fastened
to the orbiting shaft slidably in the axial direction;
[0040] FIG. 16 is a sectional view showing an overall structure of
one example of a conventional scroll compressor;
[0041] FIG. 17 is a partially exploded view of the scroll
compressor of FIG. 16; and
[0042] FIG. 18 is a schematic view showing a principle of an
anti-self-rotation mechanism of the scroll compressor of FIG.
16.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] FIG. 1 is a schematic sectional view showing a scroll
compressor according to the first embodiment of the present
invention, and FIG. 2 is a sectional view taken along the line A-A
of FIG. 1. As shown in these figures, a stationary scroll 22 is
fixed to a casing 21, and a spiral lap is provided in the
stationary scroll 22. A stator 23 is fixed to the casing 21.
Bearing supports 26 and 27 are also fixed to the casing 21, and a
rotary shaft 25 is rotatably supported by the bearing supports 26
and 27 through bearings 28 and 29. A rotor 24 is fixed to the
rotary shaft 25. A motor comprises the stator 23 and the rotor 24.
An orbiting shaft 30 is rotatably supported by the rotary shaft 25
through bearings 31 and 32, and respective axes of the rotary shaft
25 and the orbiting shaft 30 are eccentrically arranged each other.
Thus, the orbiting shaft 30 is eccentrically and rotatably
supported by the rotary shaft 25. An orbiting scroll 33 is mounted
to the upper portion of the orbiting shaft 30. The orbiting scroll
33 is provided with a lap formed in the same configuration as that
of the stationary scroll 22. These laps of the orbiting scroll 33
and the stationary scroll 22 are overlappedly engaged with each
other to form a plurality of compression chambers. A compressor
body comprises the stationary scroll 22 and the orbiting scroll 33.
An orbiting plate 34 is fixed to the lower portion of the orbiting
shaft 30, i.e., the downward section on the sheet of FIG. 1, and an
Oldham's ring 35 having protrusions 36 and 37 is provided between
the bearing support 27 and the orbiting plate 34. Grooves 38 and 39
orthogonal to each other are provided in the bearing support 27 and
the orbiting plate 34, respectively, and the protrusions 36 and 37
are engaged with the grooves 38 and 39. This construction including
the bearing support 27 and the Oldham's ring 35 provides an
anti-self-rotation device which allows the orbiting shaft 30 to be
eccentrically orbited and prevents the self-rotation of the
orbiting shaft 30. Specifically, the support member 27 as the
stationary portion of the anti-self-rotation device is fixed to the
casing 21, and the Oldham's rings 35 as the movable portion of the
anti-self-rotation device are engaged with the orbiting plate 34 as
a certain portion of an orbiting shaft. Further, a suction pipe 40
is connected to the stationary scroll 22, and a discharge pipe 41
is connected to the stationary scroll 22. Each of the suction pipe
40 and the discharge pipe 41 communicates with the compression
chambers. The eccentric-rotation driving unit comprises the casing
21, the motor, the rotary shaft 25, the orbiting shaft 30, and the
anti-self-rotation device.
[0044] In this scroll compressor, when a winding of the stator 23
is energized, the rotor 24 and the rotary shaft 25 are rotated, and
the orbiting shaft 30 is eccentrically orbited about the axis of
the rotary shaft 25. However, the anti-self-rotation device
including the Oldham's ring 35 prevents the self-rotation of the
orbiting shaft 30. Thus, the orbiting shaft 30 and the orbiting
scroll 33 are orbited eccentrically to the casing 21 and the
stationary scroll 22 without any self-rotation of the orbiting
shaft 30 and the orbiting scroll 33 and thereby the volume of the
compression chambers formed between the orbiting scroll 33 and the
stationary scroll 22 is gradually reduced. Then, a gas to be
compressed, such as air, is sucked from the suction pipe 40, and
compressed in the compression chambers, whereafter the gas is
discharged from the discharge pipe 41.
[0045] In this scroll compressor, since the support member 27 as
the stationary portion of the anti-self-rotation device is fixed to
the casing 21, and the Oldham's rings 35 as the movable portion of
the anti-self-rotation device are engaged with the orbiting plate
34 as the certain portion of an orbiting shaft, i.e. the Oldham's
rings 35 is provided between the bearing support 27 and the
orbiting plate 34, the Oldham's ring 35 does not be increased in
the temperature even in the temperature raise of the orbiting
scroll 33. Thus, longer life of the Oldham's ring 35 may be
achieved. Less thermal expansion of the Oldham's ring 35 also
provides its stable efficiency. Further, locating the Oldham's ring
35 in the lower portion of the casing 21 allows the Oldham's ring
35 to be readily lubricated, and thereby longer life and enhanced
efficient of the Oldham's ring 35 may be achieved.
[0046] FIG. 3 is a schematic sectional view showing a scroll
compressor according to the second embodiment of the present
invention, which is used as a refrigerant gas compressor. As shown
in FIG. 3, a chamber 52 is liquid-tightly fixed to the casing 51. A
stationary scroll 53 is fixed to the chamber 52, and the stationary
scroll 53 is provided with a spiral lap. A high-pressure chamber 54
is fixed to the stationary scroll 53, and a stator 55 is fixed to
the casing 51. A rotary shaft 57 is rotatably supported by the
casing 51 through ball bearings 58 and 59, and a rotor 56 is fixed
to the rotary shaft 57. A motor comprises the stator 55, the rotor
56. Further, an orbiting shaft 60 is rotatably supported by the
rotary shaft 57 through ball bearings 61 and 62. Respective axes of
the rotary shaft 57 and the orbiting shaft 60 are eccentrically
arranged each other. Specifically, the orbiting shaft 60 is
eccentrically and rotatably supported by the rotary shaft 57. An
orbiting scroll 63 is mounted to the upper portion of the orbiting
shaft 60. A seal 64 is provided between the orbiting scroll 63 and
the stationary scroll 53, and a balancer 65 is mounted to the lower
portion of the orbiting scroll 63. The orbiting scroll 63 is
provided with a lap formed in the same configuration as that of the
stationary scroll 53. Respective laps of the orbiting scroll 63 and
the stationary scroll 53 are overlappedly engaged with each other
to form a plurality of compressing chambers. Further, an orbiting
plate 66 is fixed to the lower portion of the orbiting shaft 60,
i.e., in the downward section on the sheet of FIG. 3. An Oldham's
ring 67 having protrusions 68 and 69 is provided between the casing
51 and the orbiting plate 64. A groove 70 is provided in the casing
51, and a slit 71 is provided in the orbiting plate 64. The groove
70 and the slit 71 are arranged in the directions orthogonal to
each other (In FIG. 3, while the one of the groove 70 and the slit
71 should be illustrated, for simplifying the explanation, both of
the groove 70 and the slit 71 are shown together.), and the
protrusions 68 and 69 are engaged with the groove 70 and the slit
71. This construction including a part of the casing 51 and the
Oldham's ring 65 provides the anti-self-rotation device which
allows the orbiting shaft 60 to be eccentrically orbited and
prevents the self-rotation of the orbiting shaft 60. Specifically,
the portion of the casing 51 as the stationary portion of the
anti-self-rotation device is fixed to the casing 51, and the
Oldham's ring 65 as the movable portion of the anti-self-rotation
device is engaged with the orbiting plate 66 as the certain portion
of the orbiting shaft. Further, a lid 72 is mounted to the lower
portion of the casing 51, i.e. the lower section on the sheet of
FIG. 3. A suction pipe 77 is connected to the stationary scroll 53
so as to communicate with the chamber 52 and the compressing
chambers of the compressor body. A discharge pipe 78 is connected
with the high-pressure chamber 54 so as to communicate with the
compressing chambers of the compressor body through a check valve
79. The eccentric-rotation driving unit comprises the casing 51,
the motor, the rotary shaft 57, the orbiting shaft 60, and the
anti-self-rotation device.
[0047] In this scroll compressor, when a winding of the stator 55
is energized, the rotor 56 and the rotary shaft 57 are rotated, and
the orbiting shaft 60 is eccentrically orbited about the axis of
the rotary shaft 57. However, the anti-self-rotation device
comprising the Oldham's ring 65 prevents the self-rotation of the
orbiting shaft 60. Thus, the orbiting shaft 60 and the orbiting
scroll 63 are eccentrically orbited without any rotation to the
casing 51 and the stationary scroll 53, and thereby the volume of
the compression chambers formed between the orbiting scroll 63 and
the stationary scroll 53 is gradually reduced. Then, a refrigerant
gas is sucked from the suction pipe 77, and compressed in the
compression chambers, whereafter the gas is discharged from the
discharge pipe 78.
[0048] FIG. 4 is a schematic sectional view showing a scroll
compressor according to the third embodiment of the present
invention, and FIG. 5 is a sectional view taken along the line B-B
of FIG. 4. As shown in these figure, a support member 81 is fixed
to the casing 21, and a movable plate 82 is supported by the
support member 81 so as to be movable in the longitudinal direction
on the sheet of FIG. 5. The movable plate 82 is formed with a
rectangular opening 83 having a longitudinal direction orthogonal
to the moving direction of the movable plate 82. Notched surfaces
84 are provided on both sides of the lower portion of the orbiting
shaft 30. The notched surfaces 84 are arranged in parallel with the
axis of the orbiting shaft 30, and the notched surfaces 84 are also
arranged in parallel with each other. The notched surfaces 84 are
engaged with the peripheral surface of the opening 83 extending in
the width direction of the opening 83. Specifically, this width
direction of the opening 83 corresponds to a direction
perpendicular to the longitudinal direction on the sheet of FIG. 5.
This construction including the support member 81 and the movable
plate 82 provides an anti-self-rotation device which allows the
orbiting shaft 30 to be eccentrically orbited and prevents the
self-rotation of the orbiting shaft 30. That is, the support member
81 as the stationary portion of the anti-self-rotation device is
fixed to the casing 61, and the movable plate 82 as the movable
portion of the anti-self-rotation device are engaged with the
notched surfaces 84 as the certain portion of an orbiting
shaft.
[0049] In this scroll compressor, when a winding of the stator 23
is energized, the rotor 24 and the rotary shaft 25 are rotated, and
the orbiting shaft 30 is eccentrically orbited about the axis of
the rotary shaft 25. However, the anti-self-rotation device
comprising the support member 81 and the movable plate 82 prevents
the self-rotation of the orbiting shaft 30. Thus, the orbiting
shaft 30 and the orbiting scroll 33 are eccentrically orbited
without any rotation to the casing 21 and the stationary scroll 22,
and thereby the volume of the compression chambers formed between
the orbiting scroll 33 and the stationary scroll 22 is gradually
reduced. Then, a gas to be compressed is sucked from the suction
pipe 40, and compressed in the compression chambers, whereafter the
gas is discharged from the discharge pipe 41.
[0050] In this scroll compressor, since the support member 81 as
the stationary portion of the anti-self-rotation device is fixed to
the casing 21, and the movable plate 82 as the movable portion of
the anti-self-rotation device is engaged with the notched surfaces
84 as a portion of the orbiting shaft, the movable plate 82 does
not be increased in the temperature even in the temperature raise
of the orbiting scroll 33. Thus, longer life of the movable plate
82 may be achieved. Less thermal expansion of the movable plate 82
also provides its stable efficiency. Further, locating the movable
plate 82 in the lower portion of the casing 21 allows the movable
plate 82 to be readily lubricated, and thereby longer life and
enhanced efficient of the movable plate 82 may be achieved.
[0051] In the above embodiments, the orbiting plate 34, 66 is fixed
at the lower portion of the orbiting shaft 30, 60. However, it
should be understood that the orbiting plate may be fixed to any
other portion of the orbiting shaft. When the orbiting plate, for
example, is fixed to the upper potion of the orbiting shaft, an
adverse effect of the torsion in the orbiting shaft may be reduced
and thereby the efficiency of the compressor body may be enhanced.
Further, while the notch surfaces 84 are provided in the lower
portion of the orbiting shaft 30 in the above embodiments, the
notch surfaces may be provided in any other portion of the orbiting
shaft. When the notch surface, for example, is provided in the
upper potion of the orbiting shaft, an adverse effect of the
torsion in the orbiting shaft may be reduced and thereby the
efficiency of the compressor body may be enhanced. When the
orbiting shaft is inserted into the opening, the movable plate
first is divided into two parts at the middle thereof and then
jointed after the orbiting shaft is inserted into the opening. In
addition, while the compressor body is provided to one side of the
orbiting shaft 30, 60 in the above embodiments, the compressor body
may be provided to both sides of the orbiting shaft.
[0052] As described above, the stationary portion of the
anti-self-rotation device is fixed to the casing, and the movable
portion of the anti-self-rotation device is engaged with the
certain portion of the orbiting shaft, so that the
anti-self-rotation device does not be increased in the temperature
even in the temperature raise of the orbiting scroll. Thus, longer
life of the anti-self-rotation device may be achieved. Further,
less thermal expansion of the anti-self-rotation device may provide
longer life and stable efficient of the anti-self-rotation
device.
[0053] FIG. 7 is a schematic sectional view showing a scroll
compressor according to the fourth embodiment of the present
invention, and FIG. 8 is a sectional view taken along the line C-C
of FIG. 7. As shown in these figures, a stationary scroll 122 is
fixed to a casing or fixed body 121, and a spiral lap is provided
in the stationary scroll 122. A stator 123 is fixed to the casing
121. Bearing supports 126 and 127 are also fixed to the casing 121,
and a rotary shaft 125 is rotatably supported by the bearing
supports 126 and 127 through bearings 128 and 129. A rotor 124 is
fixed to the rotary shaft 125. A motor comprises the stator 123 and
the rotor 124, and this motor serves as a driving device for
rotatably driving the rotary shaft 125. A hollow orbiting shaft 130
is rotatably supported by the rotary shaft 125 through bearings 131
and 132, and respective axes of the rotary shaft 125 and the hollow
orbiting shaft 130 are eccentrically arranged each other. Thus, the
hollow orbiting shaft 130 is eccentrically and rotatably supported
by the rotary shaft 125. A mounting member 133 is fixed within the
hollow orbiting shaft 130, and an orbiting scroll 135 is mounted to
the mounting portion 134 of the mounting member 133. The orbiting
scroll 135 is provided with a lap formed in the same configuration
as that of the stationary scroll 122. These laps of the orbiting
scroll 135 and the stationary scroll 122 are overlappedly engaged
with each other to form a plurality of compression chambers. A
compressor body comprises the stationary scroll 122 and the
orbiting scroll 135, and this compressor body is located inside the
rotor 124 and the hollow orbiting shaft 130. A hollow orbiting
plate 136 is fixed to the lower portion of the hollow orbiting
shaft 130, i.e., the downward section on the sheet of FIG. 7, and
an Oldham's ring 137 having protrusions 138 and 139 is provided
between the bearing support 127 and the hollow orbiting plate 136.
Grooves 140 and 141 orthogonal to each other are provided in the
bearing support 127 and the hollow orbiting plate 136,
respectively, and the protrusions 138 and 139 are engaged with the
grooves 140 and 141. This construction including the Oldham's ring
137 provides an anti-self-rotation device which allows the hollow
orbiting shaft 130 to be eccentrically orbited and prevents the
self-rotation of the hollow orbiting shaft 130. Specifically, the
anti-self-rotation device is provided between the hollow orbiting
plate 136 and the casing 121. Further, a suction pipe 142 is
connected to the stationary scroll 122, and a discharge pipe 143 is
connected to the stationary scroll 122. Each of the suction pipe
142 and the discharge pipe 143 communicates with the compression
chambers. The eccentric-rotation driving unit comprises the casing
121, the motor, the rotary shaft 125, the hollow orbiting shaft
130, and the anti-self-rotation device.
[0054] In this scroll compressor, when a winding of the stator 123
is energized, the rotor 124 and the rotary shaft 125 are rotated,
and the hollow orbiting shaft 130 is eccentrically orbited about
the axis of the rotary shaft 125. However, the anti-self-rotation
device including the Oldham's ring 137 prevents the self-rotation
of the orbiting shaft 130. Thus, the orbiting scroll 135 is orbited
eccentrically to the casing 121 and the stationary scroll 122
without any self-rotation of the orbiting scroll 135 and thereby
the volume of the compression chambers formed between the orbiting
scroll 135 and the stationary scroll 122 is gradually reduced.
Then, a gas to be compressed, such as refrigerant gas, is sucked
from the suction pipe 142, and compressed in the compression
chambers, whereafter the gas is discharged from the discharge pipe
143.
[0055] In this scroll compressor, the compressor body is located
inside the rotor 124 and the hollow orbiting shaft 130 so that the
dimension in the axial direction of the rotary shaft 125, i.e. in
the longitudinal direction on the sheet of FIG. 7, may be reduced.
Further, the hollow orbiting shaft 130 is not directly mounted to
the compressor body and thereby a heat of the compressor body is
hardly transmitted to the hollow orbiting shaft 130, so that the
hollow orbiting shaft 130 is not deformed by such heat. Thus, each
lap of the stationary scroll 122 and the orbiting scroll 135 may
avoid conflicting with each other, and thereby the orbiting scroll
122 and the stationary scroll 135 may be prevented from being
damaged. Furthermore, since the Oldham's ring 137 is provided
between the bearing support 127 and the hollow orbiting plate 136,
the Oldham's ring 137 does not be increased in the temperature even
in the temperature raise of the orbiting scroll 135. Thus, longer
life of the Oldham's ring 137 may be achieved. Less thermal
expansion of the Oldham's ring 137 also provides its stable
efficiency.
[0056] FIG. 9 is a schematic sectional view showing a scroll
compressor according to the fifth embodiment of the present
invention. As shown in FIG. 9, a stationary scroll 151 is fixed to
the casing 121, and the stationary scroll 151 is provided with a
spiral lap. An orbiting scroll 153 is mounted to the mounting
portion 152 of the mounting member 133. The orbiting scroll 153 is
provided with a lap formed in the same configuration as that of the
stationary scroll 151. Respective laps of the orbiting scroll 153
and the stationary scroll 151 are overlappedly engaged with each
other to form a plurality of compression chambers. A compressor
body comprises the stationary scroll 151 and the orbiting scroll
153, and this compressor body is located inside the rotor 124 and
the hollow orbiting shaft 130. Further, a suction pipe 154 is
connected to the stationary scroll 151, and a discharge pipe 155 is
connected to the stationary scroll 151. The suction pipe 154 and
the discharge pipe 155 communicate with the compression
chambers.
[0057] In this scroll compressor, a gas to be compressed is sucked
from the suction pipe 142, and compressed in the compression
chambers, whereafter the gas is discharged from the discharge pipe
143. Simultaneously, the gas to be compressed is sucked from the
suction pipe 154, and compressed in the compressed chambers,
whereafter the gas is discharged from the discharge pipe 155.
[0058] In this scroll compressor, the gas to be compressed may be
compressed by two compressor bodies; one compressor body comprising
the stationary scroll 122 and the orbiting scroll 135, and another
compressor body comprising the stationary scroll 151 and the
orbiting scroll 153. Thus, when these two compressor bodies are
connected in parallel with each other, larger volume may be
provided, and when they otherwise are connected in series with each
other, higher compressibility may be provided. Further, the
mounting portions 134 and 152 may be shortened, and thereby higher
torsional rigidity of the mounting portions 134 and 152 and less
buckling deformation may be achieved. This allows various
compressor bodies to be mounted to the mounting portions 134 and
152. Thus, the scroll compressor may assure a substantially
constant performance regardless of the temperature, and it may be
used in either of the cold and hot areas in case of applied as a
compressor for air conditioners.
[0059] FIG. 10 is a schematic sectional view showing a scroll
compressor according to the sixth embodiment of the present
invention, and FIG. 11 is a sectional view taken along the line D-D
of FIG. 10. As shown in these figure, a stationary scroll being a
part of a compressor body 162 is fixed to a casing 161. A stator
163 is fixed to the casing 161, and a bearing support 164 is fixed
to the casing 161. A rotary shaft 166 is rotatably supported by a
bearing support 164 through a bearing 165, and a rotor 168 is fixed
to the rotary shaft 166 through a coupling disk 167. A motor
comprises the stator 163 and the rotor 168. Further, an orbiting
shaft 170 is rotatably supported by the rotary shaft 166 through a
bearing 169. Respective axes of the rotary shaft 166 and the
orbiting shaft 170 are eccentrically arranged each other. Thus, the
orbiting shaft 170 is eccentrically and rotatably supported by the
orbiting shaft 170. An orbiting scroll being a part of the
compressor body 162 is mounted to the end portion of the orbiting
shaft 170, and the compressor body 162 is located inside the rotor
168. A support member 171 is fixed to the casing 161. A movable
plate 172 is supported by the support member 171 so as to be
movable in the longitudinal direction on the sheet of FIG. 11. The
movable plate 172 is formed with a rectangular opening 173 having a
longitudinal direction orthogonal to the moving direction of the
movable plate 172. Specifically, this longitudinal direction of the
rectangular opening 173 corresponds to the lateral direction on the
sheet of FIG. 11. Notched surfaces 174 are provided on both sides
of the center portion of the orbiting shaft 170. The notched
surfaces 174 are arranged in parallel with the axis of the orbiting
shaft 170, and the notched surfaces 174 are also arranged in
parallel with each other. The notched surfaces 174 are engaged with
the peripheral surface of the opening 173 extending in the width
direction of the opening 173. Specifically, this width direction of
the opening 173 corresponds to a direction perpendicular to the
longitudinal direction on the sheet of FIG. 11. This construction
including the support member 171 and the movable plate 172 provides
an anti-self-rotation device which allows the orbiting shaft 170 to
be eccentrically orbited and prevents the self-rotation of the
orbiting shaft 170. That is, the support member 171 as the
stationary portion of the anti-self-rotation device is fixed to the
casing 161, and the movable plate 172 as the movable portion of the
anti-self-rotation device are engaged with the notched surfaces 174
as a portion of the orbiting shaft. The eccentric-rotation driving
unit comprises the casing 161, the motor, the rotary shaft 166, the
orbiting shaft 170, and the anti-self-rotation device.
[0060] In this scroll compressor, when a winding of the stator 163
is energized, the rotor 168 and the rotary shaft 166 are rotated,
and the orbiting shaft 170 is eccentrically orbited about the axis
of the rotary shaft 166. However, the anti-self-rotation device
comprising the support member 171 and the movable plate 172
prevents the self-rotation of the orbiting shaft 170. Thus, the
orbiting shaft 170 and the orbiting scroll are eccentrically
orbited without any rotation to the casing 161 and the stationary
scroll, and thereby the volume of the compression chambers formed
between the orbiting scroll and the stationary scroll is gradually
reduced.
[0061] In this scroll compressor, the compressor body 162 is
located inside the rotor 168 so that the dimension in the axial
direction of the rotary shaft 166, i.e. in the longitudinal
direction on the sheet of FIG. 10, may be shorten. Further, the
diameter of the orbiting shaft 170 may be increased without
increasing the outside dimension of the scroll compressor unit, and
thereby higher rigidity of the orbiting shaft 170 and less
deformation of the orbiting shaft 170 may be achieved. Thus, each
lap of the orbiting scroll and stationary scroll in the compressor
body 162 may avoid conflicting with each other, and thereby the
orbiting scroll and stationary scroll in the compressor body 162
may be prevented from being damaged. Further, since the
anti-self-rotation device is obtained only by providing the opening
173 in the movable plate 172 and providing the notched surfaces 174
in both sides of the bottom of the orbiting shaft 170, simpler
structure and lower manufacturing cost may be achieved.
[0062] In the above embodiments, the motor including the stator 123
and the rotor 124 is used as a driving device for rotatably driving
the rotary shaft 125. However, it should be understood that a
belt-type driving device may be applied as the driving device for
rotatably driving the rotary shaft. Further, while the hollow
orbiting plate 136 is fixed at the lower portion of the hollow
orbiting shaft 130 in the above embodiments, the hollow orbiting
plate 136 may be fixed to any other portion of the hollow orbiting
shaft 130. Furthermore, while the coupling disk 167 is used as a
coupling member in the above embodiments, a plurality of coupling
rods may be applied as coupling members. In addition, in the above
embodiments, the orbiting scrolls 135 and 153 are mounted to the
mounting member 133. However, the orbiting scroll may be mounted
directly to the hollow orbiting shaft. When the compressor body is
cooled by supplying wind to the center thereof, for example, the
compressor body 162 is cooled by supplying wind to the center
thereof through the inner passage provided in the orbiting shaft
170, the thermal deformation of the compressor body may be reduced.
Thus, the interference between respective laps of the orbiting
scroll and stationary scroll in the compressor body and resulting
damage of the laps of the orbiting scroll and the stationary scroll
in the compressor body may further be prevented.
[0063] As described above, in the scroll compressor according to
the present invention, locating the compressor body inside the
orbiting shaft allows the dimension in the axial direction of the
rotary shaft to be effectively shortened. Further, locating the
compressor body inside the rotor allows the dimension in the axial
direction of the rotary shaft to be shortened.
[0064] FIG. 12 is a sectional view showing an overall structure of
one example of a scroll-type pressure transformer according to the
present invention, and FIGS. 13 and 14 are exploded views thereof.
This scroll-type pressure transformer comprises a driving unit, a
scroll device and a casing to couple them.
[0065] The driving unit comprises a motor 301, an orbiting shaft
303 located in a rotary shaft 302 of the motor 301, an
anti-self-rotation mechanism 304 of the orbiting shaft 303, and a
casing 306 for fixing the motor 301. The motor 301 comprises a
stator 301a fixed to the casing 306, a rotary shaft 302 rotatable
in a space of the stator 301a and having an eccentric axial hollow
portion therein, and a rotor 301b fixed to the rotary shaft 302 and
facing to the stator 301a with a small gap therebetween. Bearings
302a and 302b are provided on both ends of the hollow portion
within the rotary shaft 302, and the orbiting shaft 303 is
relatively rotatably supported through the bearings 302a and 302b.
The shaft center of the orbiting shaft 303 is arranged
eccentrically to the shaft center of the rotary shaft 302. Thus,
when the rotary shaft 302 is rotated, the orbiting shaft 303 is
orbited along the circumference having a radius R corresponding to
the distance R between the both shaft centers.
[0066] The anti-self-rotation mechanism 304 according to the
present invention includes an Oldham's ring 444 having a pair of
first protrusions 441, 441 provided along a diagonal line on one
side of the Oldham's ring 444 and a pair of second protrusions 442,
442 provided along a diagonal line orthogonal to the above diagonal
line on the other side of the Oldham's ring 444. An orbiting plate
446 fixed to the orbiting shaft 303 has, on the inner surface
thereof, a pair of radial grooves (not shown) which allows the
first protrusions 441 of the Oldham's ring 444 to be moved therein.
The outer surface of the casing 306 is formed with a pair of radial
grooves 448 which allows the second protrusions 442 of the Oldham's
ring 444 to be moved therein. The Oldham's ring 444 is restrained
by the radial grooves (not shown) of the orbiting plate 446 and the
radial grooves 448 of the casing 306 so that the orbiting shaft 303
may be orbited without its self-rotation.
[0067] Among a pair of stationary scroll members 340 and 342 each
having a scroll, a protrusion 345 of a stationary scroll member 342
located on the side of the motor is formed with an opening 347a
having a bearing 345a coaxial with the rotary shaft 302 to
rotatably bear the rotary shaft 302, and a through hole 347b
coaxial with the rotary shaft 302 and having an inner diameter
slightly larger than the orbiting diameter of the orbiting shaft
303. The protrusion 345 of the stationary scroll member 342 is
fixed to the casing 306 of the motor 301 by a screw or the like.
The other stationary scroll member 340 includes, on the inner
surface thereof, a scroll 340a having the same configuration as
that of the scroll 342a of the stationary scroll member 342. The
stationary scroll member 340 also has a recessed portion 340b
rotatably bearing the top portion of the orbiting shaft 303 at a
position corresponding to a through hole 344a of an orbiting scroll
member 344.
[0068] The orbiting scroll member 344 has spiral scrolls 349a and
349b on both sides thereof, and a sleeve 344b at its approximate
center thereof. The sleeve 344b is fastened to the orbiting shaft
303 by a screw, lock or the like. Thus, when both stationary scroll
members 340 and 342 are coupled through the orbiting scroll member
344 with a screw or the like, the scroll spaces are formed on both
sides of the orbiting scroll member 344. These scroll spaces are
moved toward the side of the orbiting shaft 303 (i.e. the center
side of the compressor) as they are gradually reduced in volume by
the orbiting of the orbiting scrolls 349a and 349b. Each scroll
space has a low-pressure area in the outward portion thereof and
has a high-pressure area at the center portion thereof. Since the
configuration and operation of the scroll are known, their
description will be omitted. A through hole 344d is formed in a
disk-shaped base plate 344c of the orbiting scroll member 344 in
the high-pressure area to communicate the scroll spaces on both
sides respectively. A vent passage communicating with the
low-pressure area of the scroll spaces operates as an inlet port
320, and a vent passage communicating with the high-pressure area
of the scroll spaces operates as a discharge port 322.
[0069] The scroll-type pressure transformer shown in FIGS. 12 to 14
may function as a scroll vacuum pump.
[0070] FIG. 15 is a sectional view showing an overall structure of
another example of a scroll-type pressure transformer according to
the present invention having scroll spaces on both sides thereof,
wherein the orbiting scroll member 344 fastened to the orbiting
shaft 303 is slidably in the axial direction. In FIG. 15, the same
elements as those of the scroll-type pressure transformer in FIGS.
12 to 14 are defined by the same reference numbers.
[0071] Generally, the pressure transformer, for example, is
operated under an adequate difference in gas pressure by arranging
a gas pressure in the upper scroll space higher than a gas pressure
in the lower scroll space. However, under various operation
conditions and the conditions of each portion of the orbiting
scroll member 344, such as temperature rise, and deformation by
vibration, an excessive thrust force may load to the bearing 302b
of the orbiting shaft 303. To cope with these undesirable
condition, as shown in FIG. 15, the orbiting scroll member 344 is
engaged with the orbiting shaft 303 slidably in the axial direction
by, for example, key or P-profile and fastened by a spring 350 and
a screw 351 thereto. By virtue of this structure, the above
excessive thrust force is absorbed by the spring 350 so that the
thrust force on the bearing 302b of the orbiting shaft 303 may be
reduced. Thus, the bearing of the orbiting scroll member is not
required to have an excessively high strength and thereby its cost
may be reduced.
[0072] The embodiment of the present invention has been described
with reference to the drawings of the particular embodiment.
However, the present invention is not limited to those and various
modifications may be made. For example, the anti-self-rotation
mechanism is not limited to the Oldham's ring and a crankshaft type
anti-self-rotation mechanism as shown in FIG. 18 may be applied.
Further, the anti-self-rotation mechanism is not essentially
required to mount to the orbiting shaft in the position outside the
motor farthest from the scroll as shown in FIGS. 12 and 13, and it
may be provided outside the scroll as shown in FIG. 15, or halfway
between the motor and the scroll. Further, in the motor as shown in
figures, the orbiting shaft is not essentially required to
penetrate the rotary shaft, and a commercially available motor, for
example, may be applied and an orbiting shaft may be rotatably
mounted within the hollow portion of the rotary shaft coupled to
the rotary shaft of the motor.
[0073] As described above, in the scroll-type pressure transformer
according to the present invention, the orbiting scroll member is
directly fastened or fastened slidably to the orbiting shaft which
is orbited without any self-rotation by the anti-self-rotation
mechanism provided between the orbiting plate mounted to the
orbiting shaft and the casing. Thus, the overall device may be
simplified in structure, and its cost may be reduced. Further, the
complicated mechanism is not required for the anti-self-rotation
mechanism of the orbiting shaft, and the deformation of the
orbiting scroll member due to the thermal expansion or the
vibration may be reduced. Thus, the orbiting scroll member may be
orbited precisely, and the durability and quietness of the device
may be enhanced.
* * * * *