U.S. patent application number 13/700418 was filed with the patent office on 2013-03-21 for scroll-type fluid machine.
The applicant listed for this patent is Toshiyuki Kikuchi, Takayuki Kudo, Jiro lizuka, Shinichi Ohtake, Kiyoshi Terauchi. Invention is credited to Toshiyuki Kikuchi, Takayuki Kudo, Jiro lizuka, Shinichi Ohtake, Kiyoshi Terauchi.
Application Number | 20130071279 13/700418 |
Document ID | / |
Family ID | 45003922 |
Filed Date | 2013-03-21 |
United States Patent
Application |
20130071279 |
Kind Code |
A1 |
lizuka; Jiro ; et
al. |
March 21, 2013 |
Scroll-Type Fluid Machine
Abstract
A scroll-type fluid machine (1) in which in which a spiral body
(50, 52) and an end plate (8a, 10a) come into sliding contact with
each other between fixed and movable scrolls (8, 10) with a chip
seal (56, 58), which is provided to the spiral body, intervening
therebetween. The spiral body of at least one of the scrolls is
provided, in the corner on the end plate side thereof, with a base
portion (62) formed of a concave arc face (64), and the chip seal
of the other scroll is provided, in the corner of a tip end (56a)
thereof, with a fillet (70) that is formed of a first convex arc
face (72) that comes into sliding contact with the concave arc
face.
Inventors: |
lizuka; Jiro; (Isesaki-shi,
JP) ; Terauchi; Kiyoshi; (Isesaki-shi, JP) ;
Ohtake; Shinichi; (Isesaki-shi, JP) ; Kudo;
Takayuki; (Isesaki-shi, JP) ; Kikuchi; Toshiyuki;
(Isesaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
lizuka; Jiro
Terauchi; Kiyoshi
Ohtake; Shinichi
Kudo; Takayuki
Kikuchi; Toshiyuki |
Isesaki-shi
Isesaki-shi
Isesaki-shi
Isesaki-shi
Isesaki-shi |
|
JP
JP
JP
JP
JP |
|
|
Family ID: |
45003922 |
Appl. No.: |
13/700418 |
Filed: |
May 24, 2011 |
PCT Filed: |
May 24, 2011 |
PCT NO: |
PCT/JP2011/061854 |
371 Date: |
November 27, 2012 |
Current U.S.
Class: |
418/55.2 |
Current CPC
Class: |
F01C 1/02 20130101; F04C
18/0215 20130101; F01C 19/08 20130101; F01C 19/005 20130101; F04C
18/0284 20130101 |
Class at
Publication: |
418/55.2 |
International
Class: |
F01C 19/00 20060101
F01C019/00; F01C 1/02 20060101 F01C001/02 |
Foreign Application Data
Date |
Code |
Application Number |
May 27, 2010 |
JP |
2010-121537 |
Claims
1. A scroll-type fluid machine comprising a fixed scroll and a
movable scroll each having an end plate and a spiral body integral
with the end plate, in which the spiral body and the end plate come
into sliding contact with each other between the fixed and movable
scrolls with a chip seal, which is provided to the spiral body,
intervening therebetween, thus demarcating a pressure chamber of
working fluid, which is formed between the spiral bodies,
characterized in that: the spiral body of at least one of the
scrolls has a base portion formed in a corner on the end plate side
in the form of a concave arc face, and the chip seal of the other
scroll has a fillet formed of a first convex arc face that comes
into sliding contact with the concave arc face on the corner of the
tip end of the chip seal.
2. The scroll-type fluid machine according to claim 1,
characterized in that the chip seal has an engaged portion that is
engaged with the spiral body, and the engaged portion is situated
on a more inner side than the fillet in a width direction of the
chip seal.
3. The scroll-type fluid machine according to claim 1,
characterized in that: a relationship represented by W2>W1 is
satisfied, where the width of the spiral body is W1, and the width
of the chip seal is W2.
4. The scroll-type fluid machine according to claim 1,
characterized in that: the chip seal has a second convex arc face
covering a center end portion of the spiral body, and a
relationship represented by R2>R1 is satisfied, where a
curvature radius of the first convex arc face is R1, and a
curvature radius of a second convex arc face is R2.
5. The scroll-type fluid machine according to claim 1,
characterized in that: a relationship represented by (R0-0.1
mm).ltoreq.R1.ltoreq.(R0+0.1 mm) is satisfied, where a curvature
radius of a concave arc face is R0, and a curvature radius of the
first convex arc face is R1.
6. The scroll-type fluid machine according to claim 1,
characterized in that: the first convex arc face of the fillet is
provided with an auxiliary rib for reinforcing the sealing between
the first convex arc face and the concave arc face at a third
convex arc face, and a relationship represented by
R3.ltoreq.R0.ltoreq.R1 is satisfied, where curvature radii of the
concave arc face, the first convex arc face and the third convex
arc face are R0, R1 and R3, respectively.
7. The scroll-type fluid machine according to claim 6,
characterized in that: a plurality of auxiliary ribs are arranged
more densely with decreasing distance to the center end portion of
the spiral body.
Description
TECHNICAL FIELD
[0001] The invention relates to a scroll-type fluid machine
suitable for a refrigeration circuit used for vehicle air
conditioning.
BACKGROUND ART
[0002] A scroll-type fluid machine of this type has fixed and
movable scrolls each including an end plate and a spiral body
integral with the end plate. The spiral bodies and the end plates
come into sliding contact with each other between the fixed and
movable scrolls, demarcating a compression or expansion chamber of
working fluid, which is formed between the spiral bodies.
[0003] Patent Document 1 discloses a scroll-type compressor in
which a base portion with a curvature radius (r) is provided to a
corner located on the end plate side of a spiral body of one of the
scrolls, and a rounded portion with a curvature radius (R) is
provided to a corner located on the tip end of a spiral body of the
other scroll, the curvature radius (R) being larger than the
curvature radius (r).
[0004] Patent Document 2 discloses a scroll-type compressor in
which a first chamfered portion in an arc-like shape is provided to
the base portion of a spiral body, and a second chamfered portion
in an arc-like shape, which is slightly smaller than the first
chamfered portion, is provided to a corner of the tip end of the
spiral body. The radii of first and second chamfered portions are 5
percent or less of thickness of the spiral body.
[0005] In a scroll-type compressor disclosed in Patent Document 3,
a space for a compression chamber is formed in a surface of at
least one of two scrolls, and is filled with a surface treatment
material of less hardness than the other scroll.
[0006] Patent Document 4 discloses a scroll-type fluid machine in
which an interference avoidance portion with respect to a base
portion of a spiral body is formed in a second paneling (bottom
plate).
[0007] Patent Document 5 discloses a scroll-type fluid machine in
which a spiral body and an end plate come into sliding contact with
each other between a fixed scroll and a movable scroll with a chip
seal of the spiral body intervening therebetween, and the chip seal
having a concave or convex cross-sectional shape is mounted on a
tip end of the spiral body.
PRIOR ART DOCUMENT
Patent Document
[0008] Patent Document 1: Japanese Patent No. 4126815 [0009] Patent
Document 2: Unexamined Japanese Patent Publication (Kokai) No.
5-187371 [0010] Patent Document 3: Unexamined Japanese Patent
Publication (Kokai) No. 2001-342979 [0011] Patent Document 4:
Unexamined Japanese Patent Publication (Kokai) No. 57-148085 [0012]
Patent Document 5: Unexamined Japanese Patent Publication (Kokai)
No. 2000-352388
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0013] In late years, a vehicle weight saving has been promoted due
to a rise of environmental awareness, and there is a tendency that
an engine room is made smaller and smaller for vehicle interior
comfort. Accordingly, there has been a demand for a compact
scroll-type fluid machine that is installable, for example, in a
small engine room.
[0014] On the other hand, the scroll-type fluid machine has a
scroll unit that is generally formed in a cantilever structure in
which a movable scroll makes an orbital rotation relative to a
fixed scroll. In order to downsize the scroll unit and maintain the
discharge rate of the scroll unit at the same time, a spiral body
has to be made high and is therefore prone to get damaged. For
prevention of damage, the spiral body needs to be made with an
expensive high-strength material. If any high-strength material is
unusable, the spiral body has to be made low in height. This
discourages the promotion of downsizing of fluid machines.
[0015] To downsize the fluid machines while the spiral body is made
high without using a high-strength material, the spiral body needs
to be prevented from damage by controlling stress concentration
that takes place in the spiral body due to the rotating movement of
the movable scroll.
[0016] To solve this, Patent Documents 1 and 2 provide a so-called
fillet to the base portion and tip end of the spiral body to
prevent the spiral body from being damaged. However, the fillets
have different curvature radii, and are formed directly in the
spiral bodies. This produces the possibility that the fillets are
abraded along with the rotating movement of the movable scroll.
Moreover, there is created a space having a crescent-shaped
cross-section between the base portion and the tip end of the fixed
and movable spiral bodies, so that the airtightness of the
compression or expansion chamber cannot be maintained, which might
lead to considerable deterioration of actuation efficiency of the
fluid machine.
[0017] If, as described in Patent Document 2, the curvature radius
of the fillet is set to be 5 percent or less of wall thickness of
the spiral body, it becomes difficult to completely fill the
crescent-shaped space because the fillet is too small especially if
the fluid machine is of a compact size. Furthermore, there is the
possibility that the stress concentration that takes place in the
spiral body cannot be successfully controlled.
[0018] In Patent Document 3, if the fillet is subjected to surface
treatment with a surface treatment material such as a soft metal
plating material, the surface treatment material is abraded to have
a proper film thickness. The crescent-shaped space might be able to
be filled with the fillet. On the other hand, the surface treatment
material generally has micron-order thickness, and the thickness
thereof does not take abrasion into consideration. If the surface
treatment material is too thick, it might fall out along with the
orbital rotation of the movable scroll. It is thus difficult to
fill the crescent-shaped space even if the fillet is subjected to
the surface treatment with a surface treatment material. There is
also the possibility that the stress concentration that takes place
in the spiral body cannot be successfully controlled.
[0019] In Patent Document 4, it is likely that not only the
crescent-shaped space but also another space will be created
between the base portion of the spiral body and a bottom plate. It
is then apparent that airtightness cannot be maintained in the
compression or expansion chamber.
[0020] To solve this problem, as mentioned in Patent Document 5, if
concave and convex chip seals are mounted on the tip end of the
spiral body, the crescent-shaped space can be filled with the chip
seals. However, a particular attention is given neither to the
shape of corners of tip ends of the chip seals nor to the
deformation of the chip seals, which is caused by the rotating
movement of the movable scroll. For that reason, there still is a
problem in completely filling the crescent-shaped space and
successfully controlling the stress concentration that takes place
in the spiral body.
[0021] The present invention provides a scroll-type fluid machine
that controls the stress concentration that takes place in fixed
and movable spiral bodies, and enhances the airtightness of a
compression or expansion chamber of working fluid, which is formed
between the spiral bodies, the fluid machine thus being improved in
actuation efficiency and yet being downsized.
Means for Solving the Problems
[0022] The scroll-type fluid machine of the invention includes a
fixed scroll and a movable scroll each having an end plate and a
spiral body integral with the end plate. The spiral body and the
end plate come into sliding contact with each other between the
fixed and movable scrolls with a chip seal, which is provided to
the spiral body, intervening therebetween, thus demarcating a
pressure chamber of working fluid, which is formed between the
spiral bodies. The spiral body of at least one of the scrolls has a
base portion formed in a corner on the end plate side in the form
of a concave arc face. The chip seal of the other scroll has a
fillet formed of a first convex arc face that comes into sliding
contact with the concave arc face on the corner of the tip end of
the chip seal.
[0023] Preferably, the chip seal has an engaged portion that is
engaged with the spiral body, and the engaged portion is situated
on a more inner side than the fillet in a width direction of the
chip seal.
[0024] Preferably, a relationship represented by W2>W1 is
satisfied, where the width of the spiral body is W1, and the width
of the chip seal is W2.
[0025] Preferably, the chip seal has a second convex arc face
covering a center end portion of the spiral body, and a
relationship represented by R2>R1 is satisfied, where a
curvature radius of the first convex arc face is R1, and a
curvature radius of a second convex arc face is R2.
[0026] Preferably, a relationship represented by (R0-0.1
mm).ltoreq.R1.ltoreq.(R0+0.1 mm) is satisfied, where a curvature
radius of a concave arc face is R0, and a curvature radius of the
first convex arc face is R1.
[0027] Preferably, the first convex arc face of the fillet is
provided with an auxiliary rib for reinforcing the sealing between
the first convex arc face and the concave arc face at a third
convex arc face. A relationship represented by
R3.ltoreq.R0.ltoreq.R1 is satisfied, where curvature radii of the
concave arc face, the first convex arc face and the third convex
arc face are R0, R1 and R3, respectively.
[0028] Preferably, a plurality of auxiliary ribs are arranged more
densely with decreasing distance to the center end portion of the
spiral body.
Advantageous Effects of the Invention
[0029] According to the invention, since the chip seal has the
fillet formed of the first convex arc face in the corner of the tip
end thereof, the stress concentration that takes place in the
corner of the tip end of the fixed and movable spiral bodies can be
controlled. Moreover, the fillet formed in the first convex arc
face of the chip seal of one of the scrolls comes into sliding
contact with the base portion formed in the concave arc face of the
spiral body of the other scroll, so that the airtightness of the
compression or expansion chamber of working fluid, which is formed
between the spiral bodies, is enhanced. As a result, the fluid
machine is improved in actuation efficiency and can be downsized at
the same time.
[0030] According to the invention, the chip seal has the engaged
portion that is engaged with the spiral body. The engaged portion
is situated on a more inner side than the fillet in the width
direction of the chip seal. Along with the sliding contact of the
fillet with the base portion, the fillet is allowed to be slightly
deformed. For this reason, when the fillet is pushed against the
base portion, sealability between the spiral bodies, that is,
airtightness of the pressure chamber, is further enhanced. This
further improves the actuation efficiency of the fluid machine.
[0031] According to the invention, the relationship represented by
W2>W1 is satisfied, where the width of the spiral body is W1,
and the width of the chip seal is W2. It is then possible to
reliably protect the tip end of the spiral body with the chip seal
and to firmly push the fillet against the base portion. The
sealability between the spiral bodies, that is, the airtightness of
the pressure chamber, can be further enhanced, thus further
improving the actuation efficiency of the fluid machine.
[0032] According to the invention, the chip seal has the second
convex arc face covering the center end portion of the spiral body,
and the relationship represented by R2>R1 is satisfied, where
the curvature radius of the first convex arc face is R1, and the
curvature radius of the second convex arc face is R2. Accordingly,
the chip seal can be formed into a smoothly curved face
continuously expanding in the center end portion of the spiral
body. This makes it possible to further enhance the sealability
between the spiral bodies, that is, the airtightness of the
pressure chamber, and thus to further improve the actuation
efficiency of the fluid machine.
[0033] According to the invention, the relationship represented by
(R0-0.1 mm).ltoreq.R1.ltoreq.(R0+0.1 mm) is satisfied, where the
curvature radius of the concave arc face is R0, and the curvature
radius of the first convex arc face is R1. The curvature radii of
the concave arc face and the first convex arc face can therefore be
set at values within a proper range that takes account of an
elastic deformation of the chip seal. It is then possible to
further enhance the sealability between the spiral bodies, that is,
the airtightness of the pressure chamber, and thus to further
improve the actuation efficiency of the fluid machine.
[0034] According to the invention, the first convex arc face of the
fillet is provided with the auxiliary rib for reinforcing the
sealing between the first convex arc face and the concave arc face
at the third convex arc face. The relationship represented by
R3.ltoreq.R0.ltoreq.R1 is satisfied, where the curvature radii of
the concave arc face, the first convex arc face and the third
convex arc face are R0, R1 and R3, respectively. It is therefore
possible to set the curvature radii of the concave arc face and the
first convex arc face at values within a proper range that takes
account of the abrasion of the auxiliary rib. In result, the
sealability between the spiral bodies, that is, the airtightness of
the pressure chamber, is further enhanced, so that the actuation
efficiency of the fluid machine is further improved.
[0035] According to the invention, since the auxiliary ribs are
arranged more densely with decreasing distance to the center end
portion of the spiral body, the curvature radii of the concave arc
face and the first convex arc face can be set at values within a
range that takes account of the abrasion of the auxiliary ribs in
the vicinity of the center end portion of the spiral body, where
the pressure of the pressure chamber reaches its highest. As a
result, the sealability between the spiral bodies, that is, the
airtightness of the pressure chamber, is further efficiently
enhanced, so that the actuation efficiency of the fluid machine is
further improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 is a sectional view of a scroll compressor according
to the invention.
[0037] FIG. 2 is a sectional view of a base portion of a movable
spiral body, a fixed chip seal, and a tip end of a fixed spiral
body according to a first embodiment of the invention.
[0038] FIG. 3 is a sectional view of the fixed spiral body shown in
FIG. 2, as viewed in a direction of line III-III.
[0039] FIG. 4 is a sectional view of a base portion of a movable
spiral body according to a second embodiment of the invention.
[0040] FIG. 5 is a sectional view of a fixed chip seal according to
the second embodiment of the invention.
[0041] FIG. 6 is a sectional view of a tip end of a fixed spiral
body according to the second embodiment of the invention.
[0042] FIG. 7 is a sectional view showing a state where the base
portion and the fillet are separated away from each other to face
each other at the time of fitting the movable scroll to the fixed
scroll according to the second embodiment of the invention.
[0043] FIG. 8 is a sectional view showing a state where a lateral
face of the movable spiral body is in contact with a lateral face
of the fixed spiral body at the time of fitting the movable scroll
to the fixed scroll according to the second embodiment of the
invention.
[0044] FIG. 9 is a sectional view of a relevant part, showing the
movable scroll in rotating movement according to the second
embodiment of the invention.
[0045] FIG. 10 is a sectional view of a fixed chip seal according
to a third embodiment of the invention.
[0046] FIG. 11 is a sectional view of a relevant part, showing the
movable scroll in rotating movement according to the third
embodiment of the invention.
[0047] FIG. 12 is a sectional view of the fixed spiral body shown
in FIG. 11, as viewed in a direction of line XII-XII.
[0048] FIG. 13 is a sectional view of a relevant part, showing the
movable scroll in rotating movement according to a modification
example of the invention.
[0049] FIG. 14 is a plan view of a movable scroll according to
another modification example of the invention.
[0050] FIG. 15 is a sectional view of the movable scroll shown in
FIG. 14 as viewed in a direction of line XV-XV.
MODE FOR CARRYING OUT THE INVENTION
[0051] FIG. 1 shows a scroll compressor (scroll-type fluid machine)
1 according to the invention. The compressor 1 is installed in a
refrigeration circuit for vehicle air conditioning and used to
compress a refrigerant (working fluid) circulating in the
refrigeration circuit.
[0052] The compressor 1 has a rear housing 2 and a front housing 4.
A scroll unit 6 is accommodated in the rear housing 2. The scroll
unit 6 is made up of a fixed scroll 8 fixed to the rear housing 2
and a movable scroll 10 fitted to the fixed scroll 8 in an engaged
manner. In response to an orbital rotation of the movable scroll
10, the scroll unit 6 continuously carries out a series of
processes including the suction, compression, and discharge of the
refrigerant in order.
[0053] More specifically, a discharge chamber 12 is formed in the
rear housing 2 to be located between an end plate thereof and the
fixed scroll 8 of the scroll unit 6. The discharge chamber 12 is
connectable to a discharge aperture 14 formed in an end plate 8a of
the fixed scroll 8, with a reed discharge valve 16 intervening
therebetween. The discharge chamber 12 is also connected to a
refrigerant circulating path of the refrigeration circuit through a
discharge port (not shown) formed in the rear housing 2.
[0054] The rear housing 2 is further provided with an intake port
(not shown) of the refrigerant. This intake port guides the
refrigerant from the refrigerant circulation path and introduces
the refrigerant into the rear housing 2. The refrigerant that has
been introduced into the rear housing 2 is sucked into the scroll
unit 6.
[0055] A drive shaft 18 is disposed in the front housing 4. The
drive shaft 18 has a large-diameter end 20 and a small-diameter
shaft 22. The large-diameter end 20 is rotatably supported by the
front housing 4 with a needle bearing 24 intervening therebetween.
The small-diameter shaft 22 is rotatably supported by the front
housing 4 with a ball bearing 26 intervening therebetween. A lip
seal 28 is disposed between the small-diameter shaft 22 and the
front housing 4. The lip seal 28 airtightly separates the inside of
the front housing 4.
[0056] The small-diameter shaft 22 of the drive shaft 18 is
protruding from the front housing 4. A protruding end of the
small-diameter shaft 22 is interlocked with a drive pulley 30
including a built-in electromagnetic clutch. The drive pulley 30 is
rotatably supported by the front housing 4 with a bearing 32
intervening therebetween. The drive pulley 30 is connected via a
belt to an output pulley located on the engine side of the vehicle,
and is rotated by receiving power from the engine. If the
electromagnetic clutch in the drive pulley 30 is ON while the
engine is being driven, the drive shaft 18 is rotated together with
the drive pulley 30.
[0057] A crankpin 34 is protruding from the large-diameter end 20
of the drive shaft 18 in the direction of the movable scroll 10.
The crankpin 34 supports a boss 40 of the movable scroll 10 with an
eccentric bushing 36 and the needle bearing 38 intervening
therebetween. Accordingly, when the drive shaft 18 is rotated, the
movable scroll 10 receives the rotation through the crankpin 34 and
the eccentric bushing 36 and makes a rotating movement.
[0058] A rotation preventing coupling is disposed between the front
housing 4 and an end plate 10a of the movable scroll 10. In the
case of this embodiment, the rotation preventing coupling is made
up of an EM coupling 42. The EM coupling 42 is formed by placing a
ball 48 between annular race grooves of ring-like movable and fixed
plates 44 and 46.
[0059] The fixed scroll 8 has a fixed spiral body 50 integrated
with an end plate 8a. The movable scroll 10 also has a movable
spiral body 52 integrated with the end plate 10a. Inner and outer
faces of the fixed and movable spiral bodies 50 and 52, except for
center end portions thereof, are formed of involute faces, and are
molded from aluminum alloy such as A4032-T6.
[0060] The discharge aperture 14 is positioned close to a center
end portion 54 of the fixed spiral body 50. There is secured a
certain clearance between the discharge aperture 14 and an inner
face of the center end portion 54.
[0061] The fixed spiral body 50 is provided with a fixed chip seal
56 in a tip end 50a, and the movable spiral body 52 with a movable
chip seal 58 in a tip end 52a. The fixed and movable chip seals 56
and 58 are molded from engineering plastic, such as polyphenylene
sulfide (PPS), which has an elastic modulus of approximately a
thirtieth part or less of elastic modulus of the fixed and movable
spiral bodies 50 and 52 molded from the above-mentioned aluminum
alloy.
[0062] The fixed spiral body 50 and the end plate 10a are brought
into sliding contact with each other with the fixed chip seal 56
intervening therebetween. The movable spiral body 52 and the end
plate 8a are brought into sliding contact with each other with the
movable chip seal 58 intervening therebetween. Due to the sliding
contact between the fixed and movable scrolls 8 and 10, a
compression chamber (pressure chamber) 60 of refrigerant is
demarcated and located between the fixed and movable spiral bodies
50 and 52, and the above-mentioned series of processes are
continuously carried out.
[0063] The shape of the base portion 62 of the movable spiral body
52, the fixed chip seal 56, and the tip end 50a of the fixed spiral
body 50 of the first embodiment will be described below in detail
with reference to a state at the time of the fitting of the movable
scroll 10 to the fixed scroll 8 shown in FIG. 2. The base portion
of the fixed spiral body 50, the movable chip seal 58, and the tip
end 52a of the movable spiral body 52 have the same shape as the
base portion 62 of the movable spiral body 52, the fixed chip seal
56, and the tip end 50a of the fixed spiral body 50, respectively.
The description of the base portion of the fixed spiral body 50,
the movable chip seal 58, and the tip end 52a of the movable spiral
body 52 will be therefore omitted from the descriptions of
embodiments mentioned later. The fixed spiral body 50 and the fixed
chip seal 56 may be simply referred to as a spiral body 50 and a
chip seal 56, respectively.
[0064] The movable spiral body 52 is formed to have width W1, and
has the base portion 62 in the corner of the end plate 10a side.
The base portion 62 has a concave arc face 64 with a curvature
radius R0, which is formed by using a cutting tool, such as an end
mill, in the step of cutting work of the movable spiral body
52.
[0065] The fixed chip seal 56 has substantially the same length as
the length of the fixed spiral body 50 in a spiral direction. In
the case of the present embodiment, the fixed chip seal 56 has a
concave cross-section. In contrast, the fixed spiral body 50 is
formed to have a convex cross-section. A convex portion 66 is
formed in the tip end 50a of the fixed spiral body 50. The fixed
chip seal 56 is engaged with and mounted on the fixed spiral body
50 by fitting to the convex portion 66 of the fixed spiral body 50
a concave portion (engaged portion) 68 forming the concave
cross-sectional shape of the fixed chip seal 56 along with the
spiral direction of the fixed spiral body 50.
[0066] The fixed chip seal 56 has a fillet 70 in each corner of the
tip end 56a located on the side brought into sliding contact with
the end plate 10a. The fillet 70 is provided with a first convex
arc face 72 with a curvature radius R1. The first convex arc face
72 comes into sliding contact with the concave arc face 64 of the
base portion 62 in response to the rotating movement of the movable
scroll 10.
[0067] The fixed chip seal 56 is engaged with a concave portion 68,
namely, the fixed spiral body 50 at a portion on a more inner side
than the fillet 70 in the width direction of the fixed chip seal
56. Width W2 between outer circumferential surfaces 56c of a
lateral portion 56b of the concave portion 68 is larger than at
least the width W1 of the fixed and movable spiral bodies 50 and
52. The fixed chip seal 56 has a shape that is gradually widened
from the tip end 56a towards the lateral portion 56b.
[0068] FIG. 3 is a sectional view of the fixed spiral body 56 of
FIG. 2 as viewed in a direction of line III-III. As is clear from
the drawing, the convex portion 66 of the fixed spiral body 50 is
formed up to the center end portion 54 of the fixed spiral body 50.
The fixed chip seal 56 is provided with a sac-like center end
portion 74 that covers the entire center end portion 54 of the
fixed spiral body 50. The center end portion 74 is provided with a
second convex arc face 76 with a curvature radius R2 in the
vicinity of a tip end thereof.
[0069] A relationship below is satisfied among the curvature radius
R0 of the concave arc face 64, the curvature radius R1 of the first
convex arc face 72, and the curvature radius R2 of the second
convex arc face 76.
R2>R1
(R0-0.1 mm).ltoreq.R1.ltoreq.(R0+0.1 mm)
[0070] When the above expression is true, it is possible to
maintain the sealability between the fillet 70 and the base portion
62, and materialize a smooth rotating movement of the movable
spiral body 52, while giving consideration to the moldability of
the fixed chip seal 56.
[0071] In the compressor 1 of the first embodiment, as described
above, the chip seal 56 has the fillet 70 formed of the first
convex arc face 72 in the corner of the tip end 56a thereof. This
makes it possible to control the stress concentration that takes
place in the corners of the tip ends of the fixed and movable
spiral bodies 50 and 52. Moreover, since the first convex arc face
72 of the tip end 56a comes into sliding contact with the concave
arc face 64 of the base portion 62, the airtightness of the
compression chamber 60 of refrigerant, which is formed between the
spiral bodies 50 and 52, is enhanced. At the same time, the
compression efficiency of the compressor 1 is improved, and thus,
the compressor 1 is downsized.
[0072] Since the concave portion 68 is situated in a more inner
side than the fillet 70 in the width direction of the chip seal 56,
the fillet 70 is allowed to be slightly deformed along with the
sliding contact of the fillet 70 with the base portion 62. When the
fillet 70 is pushed against the base portion 62, the fillet 70 is
deformed to fill a minute crescent-shaped space between the fillet
70 and the base portion 62. The sealability between the spiral
bodies 50 and 52, that is, the airtightness of the compression
chamber 60, can be further enhanced.
[0073] The relationship represented by R2>R1 is satisfied, where
the curvature radius of the first convex arc face 72 is R1, and
that of the second convex arc face 76 is R2. The chip seal 56 can
therefore be formed into a smooth curved face continuously
expanding in the center end portion 54 of the spiral body 50. In
result, the sealability between the spiral bodies 50 and 52, that
is, the airtightness of the compression chamber 60, is further
enhanced.
[0074] The relationship represented by (R0-0.1
mm).ltoreq.R1.ltoreq.(R0+0.1 mm) is satisfied, where the curvature
radius of the concave arc face 64 is R0, and that of the first
convex arc face 72 is R1. Accordingly, the curvature radii of the
concave arc face 64 and the first convex arc face 72 can be set at
values within a range that takes account of the elastic deformation
of the chip seal 56. It is then possible to further enhance the
sealability between the spiral bodies 50 and 52, that is, the
airtightness of the compression chamber 60.
[0075] FIGS. 4 to 6 show the detail of the shape of the base
portion 62 of the movable spiral body 52, the fixed chip seal 56,
and the tip end 50a of the fixed spiral body 50 of the second
embodiment. FIGS. 7 and 8 show a state at the time of the fitting
of the movable scroll 10 to the fixed scroll 8 of the second
embodiment. FIG. 9 shows the movable scroll 10 in rotating movement
according to the second embodiment.
[0076] As is apparent from FIGS. 4 to 6, the movable spiral body 52
includes the base portion 62 formed in the end plate 10a in a
standing manner at an angle .theta.1 (normally, .theta.1=90
degrees). The fixed chip seal 56 is so formed that an angle between
the outer circumferential surface 56c of the lateral portion 56b
forming the concave portion 68 and a tip end face 56d of the tip
end 56a, that is, an angle indicative of a degree of the gradual
widening of the fixed chip seal 56, is an angle .theta.2.
[0077] In the fixed spiral body 50, a stepped portion 78 is formed
on each side of the convex portion 66 to have width W3 that is a
width measured from the convex portion 66. In the fixed chip seal
56, the lateral portion 56b is formed to have width W4.
[0078] As described above, the fixed spiral body 50 has the width
W1 in the width direction thereof. The fixed chip seal 56 is so
formed that distance between the outer circumferential surfaces 56c
of the lateral portions 56b is equal to the width W2. The fixed
chip seal 56 is so formed that the tip end 56a has thickness T1 in
a height direction thereof, and that the lateral portion 56b has
thickness T2 in a height direction thereof.
[0079] A relationship below is satisfied among the angle .theta.1
of the base portion 62, the gradual widening angle .theta.2 of the
fixed chip seal 56, the width W1 of the fixed spiral body 50, the
width W2 between the outer circumferential surfaces 56c, the width
W3 of the stepped portion 78, the width W4 of the lateral portion
56b, the thickness T1 of the tip end 56a, and the thickness T2 of
the lateral portion 56b.
W2>W1
(W3-W4)<0.2 mm
.theta.1<.theta.2
T2>R1
(R1: the curvature radius of the first convex arc face 72)
T1>1 mm
[0080] When the above expression is true, it is possible to
maintain the sealability between the fillet 70 and the base portion
62, and materialize a smooth rotating movement of the movable
spiral body 52, while giving consideration to the moldability of
the fixed chip seal 56.
[0081] More specifically, as shown in FIG. 7, in a state where the
base portion 62 and the fillet 70 are separated away from each
other and face each other at the time of fitting the movable scroll
10 to the fixed scroll 8, the fixed chip seal 56 is in the form
that is gradually widened at the angle .theta.2. As a result, a
wedge-shaped space G is created between the lateral portion 56b
located on the opposite side to a lateral face 80 of the movable
spiral body 52 and the convex portion 66.
[0082] As shown in FIG. 8, at the time of the fitting of the
movable scroll 10 to the fixed scroll 8, if the lateral face 80 of
the movable spiral body 52 is brought into contact with a lateral
face 82 of the fixed spiral body 50, the lateral portion 56b of the
fixed chip seal 56, which is located on the lateral face 80 side,
is pushed against the lateral face 82, and the lateral portion 56b
located on the opposite side to the lateral portion 56b located on
the lateral face 80 side is further deformed in a tilted manner.
The space G is thus enlarged.
[0083] As shown in FIG. 9, when the end plate 10a of the movable
scroll 10 is pushed against the tip end face 56d of the fixed chip
seal 56, and the fixed and movable spiral bodies 50 and 52 are
firmly engaged with each other, the space G is almost totally
flattened out, and the sealing between the fillet 70 and the base
portion 62 is reinforced by an elastic force of the fixed chip seal
56.
[0084] In the compressor 1 of the second embodiment, there is a
relational expression of dimension and shape of the base portion
62, the fixed chip seal 56, and the fixed spiral body 50.
Especially, the relationship represented by W2>W1 is satisfied,
where the width of the spiral body 50 is W1, and the width of the
chip seal 56 is W2. It is therefore possible to reliably protect
the tip end face 56d of the spiral body 50 by using the chip seal
56, and firmly push the fillet 70 against the base portion 62. This
further enhances the sealability between the spiral bodies 50 and
52, that is, the airtightness of the compression chamber 60.
[0085] FIG. 10 precisely shows the shape of the fixed chip seal 56
according to a third embodiment. FIG. 11 shows the movable scroll
10 in the rotating movement according to the third embodiment. FIG.
12 shows a cross-section of the fixed spiral body 50 of FIG. 11 as
viewed in a direction of line XII-XII.
[0086] As shown in FIG. 10, according to the embodiment, the first
convex arc face 72 is provided with an auxiliary rib 86 for
reinforcing the sealing between the first convex arc face 72 and
the concave arc face 64 of the base portion 62 at the third convex
arc face 84 so that the auxiliary rib 86 is integral with the
fillet 70. The auxiliary rib 86 is molded from material having a
lower abrasion resistance at least than the end plate 10a of the
movable scroll 10, preferably has a higher abrasion resistance than
the fixed chip seal 56, and has an elastic modulus at least equal
to that of the fixed chip seal 56 or higher than that the fixed
chip seal 56.
[0087] A curvature radius R3 of the third convex arc face 84
satisfies a relationship below.
R3.ltoreq.R0.ltoreq.R1
(R0: the curvature radius of the concave arc face 64, R1: the
curvature radius of the first convex arc face 72)
[0088] When the above expression is true, it is possible to
maintain the sealability between the fillet 70 and the base portion
62, and materialize a smooth rotating movement of the movable
spiral body 52, while giving consideration to the moldability of
the fixed chip seal 56.
[0089] To be more specific, as shown in FIG. 11, during the
rotating movement of the movable scroll 10, the third convex arc
face 84 is abraded into a complementary form to the concave arc
face 64 of the base portion 62 along with the sliding contact with
the base portion 62 since the auxiliary rib 86 is molded from the
material having the above-mentioned abrasion resistance and elastic
modulus, and has the curvature radius R3 of the third convex arc
face 84. In consequence, a fourth convex arc face 88 having a
curvature radius R4 that is substantially equal to R0 is formed,
and in combination with the elastic force of the fixed chip seal
56, the sealing between the fillet 70 and the base portion 62 is
further reliably reinforced.
[0090] As shown in FIG. 12, the auxiliary ribs 86 are molded so
that the length thereof in a direction of the spirals of the fixed
spiral body 50 is reduced with decreasing distance to the central
end portion 54, and so that the auxiliary ribs 86 are arranged more
densely with decreasing distance to the center end portion 54.
[0091] As described above, in the compressor 1 of the third
embodiment, the auxiliary ribs 86 are arranged in the first convex
arc face 72 of the fillet 70. The relationship represented by
R3.ltoreq.R0.ltoreq.R1 is satisfied, where the curvature radii of
the concave arc face 64, the first convex arc face 72, and the
third convex arc face 84 are R0, R1, and R3, respectively. Since
the fourth convex arc face 88 with the curvature radius R4
substantially equal to R0 is formed, the curvature radius of the
concave arc face 64 and that of the first convex arc face 72 can be
set at values within a range that takes account of the abrasion of
the auxiliary ribs 86. As a consequence, the sealability between
the spiral bodies 50 and 52, that is, the airtightness of the
compression chamber 60, is further enhanced.
[0092] More specifically, when the fillet 70 is pushed against the
base portion 62, the wedge-shaped oil film formed in the space
created in the compression chamber 60 and the auxiliary ribs 86
work together, and thus completely block a refrigerant leakage
passage. Consequently, the sealability between the spiral bodies 50
and 52, that is, the airtightness of the compression chamber 60,
can be effectively enhanced.
[0093] Since the refrigerant leakage passage can be completely
blocked, it is possible to prevent a backward flow of the
refrigerant, a decrease in refrigerant pressure, and noises caused
by fluctuations of the movable scroll, attributable to the above
phenomena.
[0094] Since the auxiliary ribs 86 are arranged more densely with
decreasing distance to the center end portion 54 of the spiral body
50, the curvature radii of the concave arc face 64 and the first
convex arc face 72 can be set at values within the range that takes
account of the abrasion of the auxiliary ribs 86 in the vicinity of
the center end portion 54 where the pressure of the compression
chamber 60 reaches its highest. As a result, the sealability
between the spiral bodies 50 and 52, that is, the airtightness of
the compression chamber 60, can be further enhanced.
[0095] The invention is not limited to the above-described
embodiments, and may be modified in various ways.
[0096] For example, the chip seal 56 of the invention is not
necessarily limited in shape. A convex portion (engaged portion) 92
of the chip seal 90, which is formed to have a convex
cross-sectional shape, for example, as shown in FIG. 13, may be
mounted in a concave portion 94, which is formed in the tip end
50a.
[0097] The chip seal 56 and the auxiliary ribs 86 of the invention
do not always have to be formed in the entire circumference of the
spiral bodies 50 and 52. For example, as shown in FIGS. 14 and 15,
the movable chip seal 58 of the invention may be formed at least
only in a single roll of the spirals, which starts from the center
end portion of the movable spiral body 52. By so doing, it is
possible to effectively reinforce, at low cost, the sealing of the
compression chamber 60 exposed to high pressure, which is located
close to the center end portion of the movable spiral body 52.
[0098] In the above-mentioned case, it is preferable that an outer
end 96 of the movable chip seal 58 have an end surface that is
formed along a rotating direction (direction of the arrow in FIG.
14) of the movable scroll 10, because the outer end 96 is pushed
against the tip end 50a of the fixed spiral body 50 due to the
pressure of the compression chamber 60 formed closer to the center
end portion than to the outer end 96, and the compression chamber
60 is thus firmly sealed.
[0099] Furthermore, according to the invention, the fillet 70 and
the auxiliary ribs 86 may be provided to the chip seal of the
spiral body of at least one of the fixed and movable scrolls 8 and
10. It is not always necessary to provide these elements to both
the fixed and movable chip seals 56 and 58 or both the fixed and
movable spiral bodies 50 and 52.
[0100] Needless to say, the invention may be applied not only to
scroll compressors but also to any scroll-type fluid machine, such
as a scroll expansion machine, in which an expansion chamber is
demarcated as a refrigerant pressure chamber.
EXPLANATION OF REFERENCE SIGNS
[0101] 1 scroll compressor (scroll-type fluid machine) [0102] 8
fixed scroll [0103] 8a end plate [0104] 10 movable scroll [0105]
10a end plate [0106] 50 fixed spiral body (spiral body) [0107] 52
movable spiral body (spiral body) [0108] 54 center end portion
[0109] 56 fixed chip seal (chip seal) [0110] 56a tip end [0111] 58
movable chip seal (chip seal) [0112] 60 compression chamber
(pressure chamber) [0113] 62 base portion [0114] 64 concave arc
face [0115] 68 concave portion (engaged portion) [0116] 70 fillet
[0117] 72 first convex arc face [0118] 76 second convex arc face
[0119] 84 third convex arc face [0120] 86 auxiliary rib [0121] 90
fixed chip seal (chip seal) [0122] 92 convex portion (engaged
portion)
* * * * *