[0001] The present invention relates to a scroll fluid machine according to the preamble
of claim 1. Such a fluid machine is known e.g. from
JP-A-57015996 or
JP-A-06280760.
Background Art of the Invention
[0002] For example, a scroll fluid machine used as a fluid machine in a refrigeration circuit
of an air conditioning system for vehicles has a scroll unit, and the scroll unit
includes a fixed scroll and a movable scroll. Each of these fixed scroll and movable
scroll has an end plate and a scroll wall integral with the end plate, and the scrolls
are disposed at a condition where both scroll walls are engaged with each other so
that therebetween a gas-tight pressure chamber (fluid pocket) is formed via a chip
seal on the tip of the scroll wall. The movable scroll is operated at an orbital movement
relative to the fixed scroll by receiving a drive force via an orbital unit, and by
the change of the displacement and the position of the above-described pressure chamber
accompanied with this orbital movement, the fluid (fro example, refrigerant) in the
pressure chamber is compressed or expanded (for example, Patent document 1).
Patent document 1:
JP-A-8-261171
[0003] In the conventional scroll fluid machine as described above, because the scroll walls
of the fixed scroll and the movable scroll locally slide relatively to each other
to form a pressure chamber, if the sliding contact condition between the scroll walls
can be relaxed, the lives of these fixed scroll and movable scroll, ultimately, the
life of the fluid machine, may be extended.
[0004] Where, in order to relax the sliding contact condition between the scroll walls,
for example, a fine gap may be secured between both scroll walls within a range which
does not decrease the sealability of the pressure chamber, and the scroll walls may
be in non-sliding contact with each other. In order to secure a fine gap, however,
the processing accuracy and the assembly accuracy of not only the fixed scroll and
the movable scroll but also the orbital unit have to be increased.
[0005] Further, because a great centrifugal force acts on the movable scroll as its orbital
speed becomes faster, if a fine gap is secured, the orbital posture of the movable
scroll in a high speed range becomes unstable, and depending upon the posture, there
may be a fear that a galling occurs between the scroll walls. Therefore, when a fine
gap is secured, it is necessary to increase the rigidity of the orbital unit or to
employ a design change such as addition of parts to the orbital unit, so as to stabilize
the orbital posture of the movable scroll.
[0006] Thus, if a fine gap is tried to be provided between the scroll walls, it becomes
necessary to increase the processing accuracy or the assembly accuracy of the scroll
unit or the orbital unit, to increase the rigidity of the orbital unit, or to change
the design such as addition of parts to the orbital unit, and therefore, reduction
in productivity or cost up of the fluid machine may be caused.
[0007] JP-06-280760 A discloses a generic scroll fluid machine having a scroll unit that comprises a fixed
scroll and a movable scroll each constructed from an end plate and a scroll wall integral
with said end plate, and comprises a chip seal provided at a tip of a scroll wall
of one of said scrolls and in relative sliding contact with an end plate of the other
scroll, wherein said scroll unit further comprises a radial projection provided on
a first wall surface as one of wall surfaces of said scroll walls facing each other
and being in relative sliding contact with a second wall surface as the other wall
surface to define a fine gap between said wall surfaces when a pressure chamber is
formed between said fixed scroll and said movable scroll.
[0009] It is the object of the present invention to provide a scroll fluid machine where
the fine gap can be accurately maintained. This object is solved by the scroll fluid
machine having the features of claim 1. The invention is further developed as it is
defined in the dependent claims.
[0010] Various forms can be employed as the scroll fluid machine according to the present
invention, and for example, it can be formed as a compressor or an expander, and further,
as a scroll fluid machine having both functions of compression and expansion. For
example, it can be structured as a scroll fluid machine wherein a motor is further
provided, and the scroll unit is provided on each end of a rotational shaft of the
motor.
[0011] In the scroll fluid machine according to the present invention, since the radial
projection secures a fine gap between the wall surfaces of both scroll walls, the
sliding contact condition between the scroll walls can be relaxed while the sealability
of the pressure chamber can be maintained, and abrasion of the scroll walls can be
suppressed. Further, in this fluid machine, by the structure in which the radial projection
secures a fine gap between the wall surfaces of the scroll walls, even if the movable
scroll is operated at a high-speed orbital movement, the orbital posture of the movable
scroll is not disturbed, and occurrence of a galling between the scroll walls can
be prevented. Consequently, the fluid machine according to the present invention has
an excellent durability.
[0012] Further, in the scroll fluid machine according to the present invention, by the structure
in which a fine gap is secured between the scroll walls, it is not necessary to mix
a lubricant oil in the operational fluid, and the structure is preferable for making
the machine oil-free. Therefore, for example, in a refrigeration circuit applied with
this fluid machine, because it is not necessary to mix a lubricant oil in the refrigerant,
the coefficient of performance of the refrigeration circuit is improved. Moreover,
because it is not necessary to mix a lubricant oil in the operational fluid, this
fluid machine can be applied to various uses.
[0013] Further, in the scroll fluid machine according to the present invention, if the radial
projection is formed integrally with the chip seal, because the number of parts does
not increase, reduction in productivity and cost up can be prevented. Further, by
the structure in which the radial projection is formed integrally with the chip seal,
because a fine gap can be easily secured even at a position which is most apart from
an end portion of a drive shaft supporting the movable scroll, even when the movable
scroll is operated at a high-speed orbital movement, disturbance of the orbital posture
of the movable scroll can be surely prevented.
[0014] Further, in a case where the chip seal has a top seal surface and a sliding contact
surface for securing a fine gap, while an excellent durability can be given to each
of the top seal surface and the sliding contact surface, both surfaces can well exhibit
respective target functions. Further, in this case, because the chip seal has the
top seal surface projecting from the tip of the scroll wall, during the operation,
the surface contact pressure between the chip seal and the end plate may be reduced
appropriately, and the durability of the chip seal may be increased.
[0015] Further, in a case where a holding means for holding the chip seal at the tip of
the scroll wall is further provided, it becomes possible to easily hold the radial
projection on the scroll wall side by this holding means. Further, by the structure
in which the holding means includes a recessed portion and a projected portion which
are provided on the chip seal and the scroll wall and which are engaged with each
other, the radial projection can be held on the scroll wall side more easily and more
securely. Furthermore, by the structure in which the holding means includes an adhesive
layer, the radial projection can be held on the scroll wall side further easily and
further securely.
[0016] Further, in a case where the chip seal is made of one material selected from the
group consisting of a polyphenylenesulfide group resin (PPS group resin), a polyetheretherketone
group resin (PEEK group resin) and a polyimide group resin (PI group resin) which
are excellent in abrasion resistance, the durability of the scroll fluid machine can
be further increased.
[0017] Furthermore, in a case where the scroll fluid machine according to the present invention
is formed as a structure wherein a motor is further provided, and the scroll unit
is provided on each end of a rotational shaft of this motor (namely, a structure having
two pressure chambers), it is possible to use one pressure chamber as a chamber for
compression and use the other pressure chamber as a chamber for expansion. In such
a structure, since the expansion energy of an operational fluid in the expansion chamber
can be used as an auxiliary power for compressing an operational fluid in the compression
chamber, the consumption power may be saved.
Brief explanation of the drawings
[0018]
[Fig. 1] Fig. 1 is a vertical sectional view of a scroll fluid machine applied to
a refrigeration circuit according to an embodiment of the present invention.
[Fig. 2] Fig. 2 is a back surface view of a chip seal applied to the fluid machine
depicted in Fig. 1.
[Fig. 3] Fig. 3 is an elevational view of a movable scroll applied to the fluid machine
depicted in Fig. 1.
[Fig. 4] Fig. 4 is a plan view showing the movable scroll depicted in Fig. 3 together
with the chip seal depicted in Fig. 2.
[Fig. 5] Fig. 5 is an enlarged, partial sectional view as viewed along V-V line of
Fig. 4.
[Fig. 6] Fig. 6 is an explanation diagram showing the sliding contact position between
scroll walls of a fixed scroll and a movable scroll and a chip seal in the fluid machine
depicted in Fig. 1.
[Fig. 7] Fig. 7 is an elevational view of a movable scroll according to a comparative
example not belonging to the present invention.
[Fig. 8] Fig. 8 is a sectional view showing a part of a scroll wall together with
a chip seal according to a modification of the present invention.
[Fig. 9] Fig. 9 is a sectional view showing a part of a scroll wall together with
a chip seal and a radial projection according to another modification of the present
invention.
Explanation of symbols
[0019]
1: scroll fluid machine
35: scroll unit
36: fixed scroll
38: movable scroll
36a, 38a: end plate
36b, 38b: scroll wall
40: pressure chamber
42: chip seal
42b: seal surface (top seal surface)
42c: outer side surface (sliding contact surface)
G: fine gap
The Best mode for carrying out the Invention
[0020] Hereinafter, desirable embodiments of the present invention will be explained referring
to figures.
Fig. 1 depicts a scroll fluid machine 1 according to an embodiment of the present
invention, which is applied, for example, to a refrigeration circuit of an air conditioning
system for vehicles. The refrigeration circuit has a circulation passageway 2, and
refrigerant as the operational fluid is circulated in the circulation passageway 2.
Where, a lubricant oil is not mixed in the refrigerant, and this refrigeration circuit
is oil free. In this embodiment, fluid machine 1 has both functions of a compressor
and an expander, and the fluid machine disposed in circulation passageway 2 divides
the circulation passageway 2 into a high-pressure region 2a and a low-pressure region
2b. In high-pressure region 2a, a condenser 4 and a receiver 6 are disposed in order
in the circulation direction of refrigerant, and in low-pressure region 2b, an evaporator
8 is interposed.
[0021] Fluid machine 1 has a motor housing 10, and the motor housing 10 has a motor casing
12 with a cup-like shape and an end plate 14 fixed to the opening end of the motor
casing 12. A cylindrical stator 16 is fitted into a circumferential wall 12a of casing
12, and stator 16 surrounds a columnar rotor 18 free to rotate. A drive shaft 20 extends
through the center of rotor 18, and the rotor 18 rotates integrally with drive shaft
20. Shaft holes are provided on the central parts of end wall 12b of casing 12 and
end plate 14, respectively, and both end portions of drive shaft 20 are projected
from these shaft holes. Drive shaft 20 is supported free to rotate by end wall 12b
and end plate 14 via ball bearings 22 provided in the shaft holes. Further, in the
shaft holes, lip seals 24 are provided at positions outside ball bearings 22, and
the shaft holes are closed by the lip seals 24.
[0022] A power supply port 26 is provided to circumferential wall 12a of motor casing 12,
and power can be supplied to stator 16 from an external power source (not shown) through
power supply port 26. When power is supplied to stator 16, rotor is rotated by the
electromagnetic force of stator 16, thereby rotating drive shaft 20.
[0023] A compression housing is provided to each end of the above-described motor housing
10, and the compression housing has a cup-like compression casing 30. Compression
casing 30 is fixed to motor housing 10 by a plurality of bolts 32, and the opening
end of compression casing 30 is fitted at a gas-tight condition to each end of motor
housing 10 via O-ring 34.
[0024] A scroll unit 35 is provided in compression casing 30, and scroll unit 35 has metal
fixed scroll 36 and movable scroll 38. These fixed scroll 36 and movable scroll 38
have end plates 36a, 38a and scroll walls 36b, 38b integral with end plates 36a, 38a,
and in this fluid machine 1, the end wall of compression casing 30 is formed also
as end plate 36a of fixed scroll 36.
[0025] These fixed scroll 36 and movable scroll 38 are disposed so as to be engaged with
each other in order to form pressure chamber 40 (fluid pocket) therebetween. Under
this disposition, movable scroll 38 can be operated at an orbital movement relative
to fixed scroll 36, and accompanied with this orbital movement, pressure chamber 40
is changed in its displacement as well as in its position.
[0026] Resin chip seals 42 are provided on the tips of scroll walls 36b, 38b, respectively,
and scroll walls 36b, 38b of fixed scroll 36 and movable scroll 38 are in sliding
contact with end plates 36a, 38a of scrolls 36, 38 positioned at the respective counter
sides, via chip seals 42.
[0027] Hereinafter, chip seal 42 will be explained, and because the structures of chip seals
42 provided on fixed scroll 36 and movable scroll 38, and fixing means of chip seals
42 to scroll walls 36b, 38b, are same as each other, the explanation will be carried
out by exemplifying chip seal 42 of movable scroll 38 side.
[0028] As shown in Fig. 2, chip seal 42 extends spirally, and has constant width and thickness.
From the back surface among both flat surfaces parallel to each other which define
the thickness of chip seal 42, pins 42a are projected at predetermined positions in
the lengthwise direction (spiral direction).
[0029] As shown in Fig. 3, on the tip of scroll wall 38b to be attached with chip seal 42,
the region connected to the outer wall surface among both wall surfaces of scroll
wall 38b is formed as a flat surface 46 at a position close to end plate 38a as compared
with tip surface 44 connected to the inner wall surface. Flat surface 46 also extends
spirally, and pin holes 46a are formed at predetermined positions in the lengthwise
direction.
[0030] As shown in Fig. 4, chip seal 42 is overlapped with flat surface 46, and at that
time, pins 42a are inserted into pin holes 46a. Therefore, as shown in Fig. 4, by
the fitting of pins 42a into pin holes 46a, chip seal 42 is fixed to the tip of scroll
wall 38b.
[0031] Where, as shown in Fig. 5, a part of chip seal 42 is projected at a predetermined
length from tip surface 44 of scroll wall 38b in the thickness direction of chip seal
42, and the front surface of chip seal 42 is parallel to the tip surface 44 of scroll
wall 38b, but is positioned near end plate 36a of fixed scroll 36 as compared with
the tip surface 44. Therefore, the front surface of chip seal 42 forms a seal surface
42b which is in sliding contact with end plate 36a of fixed scroll 36, over its entire
region.
[0032] Further, a part of chip seal 42 is projected at a predetermined length from the outer
wall surface of scroll wall 38b in the width direction of chip seal 42 (the radial
direction of scroll wall 38b), and outer side surface 42c among both side surfaces
defining the width of chip seal 42 is parallel to the outer wall surface of scroll
wall 38b, but is positioned near the inner wall surface of scroll wall 36b of fixed
scroll 36 as compared with this outer wall surface. Therefore, at the position in
the lengthwise direction where scroll walls 36b, 38b are closest to each other, outer
side surface 42c of chip seal 42 is in sliding contact with the inner wall surface
of scroll wall 36b of fixed scroll 36. At this position in the lengthwise direction,
a fine gap G is formed between the inner and outer wall surfaces of scroll walls 36b,
38b via chip seal 42.
[0033] In more detail, Fig. 6 is a modification diagram for explaining the sliding contact
positions between scroll walls 36b, 38b and outer side surface 42c of chip seal 42,
and outer side surface 42c of chip seal 42 at movable scroll 38 side is in sliding
contact with the inner wall surface of scroll wall 36b of fixed scroll 36 at two positions
(points A, B). On the other hand, outer side surface 42c of chip seal 42 at fixed
scroll 36 side is in sliding contact with the inner wall surface of scroll wall 38b
of movable scroll 38 at two positions (points C,D).
[0034] Fine gap G is formed between the inner and outer wall surfaces of scroll walls 36b,
38b at each of these points A, B, C, D in the lengthwise direction, and each of points
A, B, C, D is positioned at each end of each pressure chamber 40 in the lengthwise
direction of scroll walls 36b, 38b. Where, outer side surface 42c of each chip seal
42 is in sliding contact with the inner wall surface at a position near the root of
each of scroll walls 36b, 38b. Further, in Figs. 4 and 6, in order to indicate chip
seal 42 clearly, the hatching is provided only to chip seal 42.
[0035] Referring to Fig. 1 again, movable scroll 38 is connected to each end of drive shaft
20 via an orbital unit to enable the orbital movement of movable scroll 38. In more
detail, an eccentric bush 50 is fixed to each end of drive shaft 20, and the eccentric
bush 50 can be rotated integrally with drive shaft 20. Eccentric bush 50 is surrounded
by a boss provided integrally to the outer surface of end plate 38a, and between the
eccentric bush 50 and the boss, ball bearing 52 is interposed.
[0036] Further, a rotation preventing mechanism for preventing the rotation of movable scroll
38 around eccentric bush 50 is provided between end plate 38a of each movable scroll
38 and end wall 12b or end plate 14. The rotation preventing mechanism includes, for
example, a crank pin 54, and the crank pin 54 connects between end wall 12b or end
plate 14 and end plate 38a via two ball bearings 56.
[0037] Where, counter weights 58 are attached to drive shaft 20 at positions of both sides
of rotor 18, and the counter weights 58 become balance weights for the orbital movements
of movable scrolls 38. High-pressure ports 60 and low-pressure ports (not shown) are
provided on compression casing 30 for supplying and discharging high-pressure and
low-pressure refrigerants to and from both scroll units 35. In more detail, each high-pressure
port 60 provided through the end wall of compression casing 30, namely, the central
part of end plate 36a of fixed scroll 36, and pressure chamber 40 positioned at the
central part of end plate 36a is connected to high-pressure region 2a of circulation
passageway 2 via the high-pressure port 60. The low-pressure port is provided through
the circumferential wall of compression casing 30, and the inside of compression casing
30 is connected to low-pressure region 2b of circulation passageway 2 via the low-pressure
port.
[0038] Hereinafter, the operation of scroll fluid machine 1 in the above-described refrigeration
circuit will be explained.
When rotor 18, that is, drive shaft 20, is rotated by the power supply to stator 16,
accompanied with the rotation of drive shaft 20, movable scroll 38 is served to an
orbital movement via eccentric bush 50. By this orbital movement, scroll unit 35 on
the left side in Fig. 1 carries out the following compression process.
[0039] First, the left-side scroll unit 35 sucks low-pressure gas refrigerant from low-pressure
region 2b of circulation passageway 2 into pressure chamber 40 positioned at the outer
circumferential region through the low-pressure port and the space between scroll
unit 35 and compression casing 30. Thereafter, the pressure chamber 40 having sucked
the refrigerant moves toward the central portions of end plates 36a, 38a along scroll
walls 36b, 38b, and during this movement, the refrigerant in the pressure chamber
40 is compressed by reduction of the volume of the pressure chamber 40. Then, the
refrigerant compressed in the pressure chamber 40 flows out to high-pressure region
2a of circulation passageway 2 through high-pressure port 60 when the pressure chamber
40 is communicated with the high-pressure port 60 at the central portions of end plates
36a, 38a.
[0040] The high-pressure gas refrigerant flowed into high-pressure region 2a is cooled and
condensed at condenser 4, and after becoming a high-pressure liquid refrigerant, bubbles
and moisture are removed at receiver 6. The high-pressure liquid refrigerant having
passed through receiver 6 is supplied to the right-side scroll unit in Fig. 1, and
this right-side scroll unit 35 carries out the following expansion process.
[0041] In the right-side scroll unit 35, the high-pressure liquid refrigerant sent from
high-pressure region 2a of circulation passageway 2 flows into pressure chamber 40
positioned at the central portions of end plates 36a, 38a through high-pressure port
60. Thereafter, the pressure chamber 40, into which the refrigerant has flowed, moves
toward the outer circumferential portions of end plates 36a, 38a along scroll walls
36b, 38b, and during this movement, the refrigerant in the pressure chamber 40 is
expanded by increase of the volume of the pressure chamber 40.
[0042] The refrigerant expanded in pressure chamber 40 flows into low-pressure region 2b
of circulation passageway 2 through the space between scroll unit 35 and compression
casing 30 and the low-pressure port at the outer circumferential region of scroll
unit 35 when the pressure chamber 40 communicates with the space. The gas/liquid mixed
low-pressure refrigerant flowed out to low-pressure region 2b becomes low-pressure
gas refrigerant, and thereafter, the refrigerant is sucked again into pressure chamber
40 of left side scroll unit 35.
[0043] In the above-described scroll fluid machine 1, a part of chip seal 42 (that is, a
radial projection) is radially projected from the outer wall surface of scroll wall
36b, 38b, and fine gap G is secured between the inner and outer wall surfaces of scroll
walls 36b, 38b, thereby relaxing the sliding contact conditions between scroll walls
36b, 38b. Consequently, the abrasion of scroll walls 36b, 38b can be suppressed in
this scroll fluid machine 1.
[0044] Further, in this scroll fluid machine 1, because a part of chip seal 42 (radial projection)
secures the fine gap G between the inner and outer wall surfaces of scroll walls 36b,
38b, even in a case where movable scroll 38 is in an orbital movement at a high speed,
the orbital posture of the movable scroll 38 is not be disturbed. As a result, occurrence
of galling between scroll walls 36b, 38b can be prevented.
[0045] Thus, since the abrasion of scroll walls 36b, 38b can be suppressed and the occurrence
of galling between scroll walls 36b, 38b can be prevented by a part of chip seal 42
(radial projection), this scroll fluid machine 1 has an excellent durability. Besides,
in this scroll fluid machine 1, because the fine gap G is secured between scroll walls
36b, 38b, even if lubricant oil is not mixed in the refrigerant, seizure does not
occur between scroll walls 36b, 38b. Therefore, in a refrigeration circuit applied
with this fluid machine 1, it is possible to make the refrigeration circuit oil-free,
and in such a case, because a lubricant oil is not mixed in the refrigerant, the circuit
has a good coefficient of performance. Moreover, because it is not necessary to mix
a lubricant oil in the operational fluid, this fluid machine 1 can be applied to various
uses.
[0046] Further, in this refrigeration circuit, since scroll units 35 each functioning as
a compressor or an expander are provided to both ends of the drive shaft, it is possible
to save the consumption power. This is because the expansion of the refrigerant in
pressure chamber 40 of right-side scroll unit 35 gives an auxiliary power to drive
shaft 20 via the orbital movement of movable scroll 38, and by utilizing this auxiliary
power, the refrigerant can be compressed in pressure chamber 40 of left-side scroll
unit 35.
[0047] Where, in this scroll fluid machine 1, it is possible to maintain the sealability
of pressure chamber 40 by making the fine gap G several-tens µm or less.
[0048] The present invention is not limited to the above-described embodiment, and various
modifications can be employed.
For example, although, in the above-described embodiment, pins 42a are formed on chip
seal 42 and pin holes 46a are formed on flat surface 46 as a holding means for holding
chip seal 42 on scroll walls 36b, 38b, the pin holes may be formed on chip seal 42
and the pins may be formed on flat surface 46. However, from the viewpoint of the
productivity of the fluid machine, it is preferred that pins 42a are formed on chip
seal 42 and pin holes 46a are formed on flat surface 46.
[0049] Further, as a comparative example not belonging to the invention, a projected strip
may be formed instead of pins 42a, and as shown in Fig. 7, a groove 46b for fitting
the projected strip thereinto may be formed instead of pin holes 46a. Namely, the
holding means may be provided between scroll walls 36b, 38b and chip seal 42 and may
include a recessed portion and a projected portion being engaged with each other,
and by such a holding means, chip seal 42 can be held by scroll walls 36b, 38b easily
and securely.
[0050] Moreover, the holding means may include an adhesive layer 70 as shown in Fig. 8.
Further, although a part of chip seal 42 is projected from the outer wall surface
of scroll wall 36b or 38b in the aforementioned embodiment, a part of chip seal 42
may be projected from the inner wall surface of scroll wall 36b or 38b.
[0051] Further, as shown in Fig. 8, a chip seal 72 having a portion projected from the outer
and inner wall surfaces of scroll wall 36b or 38b may be employed. In this case, when
pressure chamber 40 is formed, outer wall surface 72c and inner wall surface 72d of
chip seal 72 is in sliding contact with the inner wall surface and outer wall surface
of counter-side scroll wall 36b or 38b, and a fine gap G is secured at each sliding
contact portion. Therefore, in this case, although chip seal 72 may be provided on
both of fixed and movable scrolls 36, 38, chip seal 72 may be provided on one of fixed
scroll 36 and movable scroll 38, and a conventional chip seal may be provided on the
other scroll.
[0052] Further, as shown in Fig. 9, a radial projection 76 may be provided as a member separate
from a conventional chip seal 74. In this case, by radial projection 76, a fine gap
G can be secured between the inner and outer wall surfaces of scroll walls 36b, 38b.
However, in a case where chip seal 74 and radial projection 76 are formed separately
from each other, because the number of parts increases and it is necessary to provide
means for holding chip seal 74 and radial projection 76 on scroll walls 36b, 38b,
respectively, thereby causing a reduction of productivity and an increase of cost
of the fluid machine, a structure is preferred wherein a part of chip seal 42 is projected
from the outer wall surface as in the aforementioned embodiment. In other words, it
is preferred that radial projection 76 is formed integrally with chip seal 74.
[0053] Further, if a part of chip seal 42 is projected from the outer wall surface of scroll
wall 36b or 38b as in the aforementioned embodiment, because a fine gap G between
scroll walls 36b, 38b is defined at a position most apart from the end of drive shaft
20 supporting movable scroll 38, even if the movable scroll 38 is operated at a high-speed
orbital movement, the disturbance of the orbital posture of the movable scroll 38
can be prevented securely.
[0054] Furthermore, if a part of chip seal 42 is projected from the outer wall surface of
scroll wall 36b or 38b as in the aforementioned embodiment, because a seal surface
42b can be formed also on the projected portion, during the operation of the fluid
machine, the surface pressure between chip seal 42 and end plates 36a, 38a can be
reduced, and the durability of chip seal 42 can be increased. Therefore, as chip seal
42, it is preferred that seal surface 42b extends up to the projected portion in the
width direction and an outer side surface 42c is connected perpendicularly to the
side edge of the seal surface 42b.
[0055] In fluid machine 1 according to the aforementioned embodiment, it is preferred that
chip seal 42 is made of one material selected from the group consisting of a polyphenylenesulfide
group resin (PPS group resin), a polyetheretherketone group resin (PEEK group resin)
and a polyimide group resin (PI group resin), because these resins are excellent in
abrasion resistance, thereby further improving the durability of the fluid machine.
[0056] Although fluid machine 1 according to the aforementioned embodiment has two scroll
units 35 provided on both end portions of drive shaft 20, the scroll fluid machine
according to the present invention may have at least one scroll unit.
Industrial Applications of the Invention
[0057] The scroll fluid machine according to the present invention can be applied to any
fluid machine having a scroll unit, and in particular, it is suitable as a fluid machine
used for a refrigeration circuit in an air conditioning system for vehicles.
1. Machine fluidique à volute (1) ayant une unité de volutes (35) comprenant une volute
fixe (36) et une volute mobile (38) réalisée chacune à partir d'un plateau d'extrémité
(36a, 38a) et d'une paroi de volute (36b, 38b) réalisée intégralement avec le plateau
d'extrémité (36a, 38a), et comprenant une lamelle d'étanchéité (42, 72, 74) située
à l'extrémité d'une paroi de volute (38b) de l'une des volutes (38) et en contact
glissant relatif avec le plateau d'extrémité (36a) de l'autre volute (36), l'unité
de volutes (35) comprenant en outre un prolongement radial situé sur une première
surface de paroi constituant l'une des surfaces de paroi des parois de volute (36b,
38b) situées en regard et en contact glissant relatif avec une seconde surface de
paroi constituant l'autre surface de paroi pour définir un faible interstice (G) entre
ces surfaces de paroi lorsqu'une chambre sous pression (40) est formée entre la volute
fixe (36) et la volute mobile (38),
caractérisée en ce que
des broches (42a) sont prévues sur un côté de la lamelle d'étanchéité (42), des orifices
de réception de broches (46a) sont prévus sur un côté d'une surface plate (46), et
les broches (42a) sont respectivement insérées dans des orifices de réception de broches
(46a) correspondants.
2. Machine fluidique à volute (1) conforme à la revendication 1, dans laquelle le prolongement
radial est formé intégralement avec la lamelle d'étanchéité (42, 72, 74).
3. Machine fluidique à volute (1) conforme à la revendication 2, dans laquelle la lamelle
d'étanchéité (42, 72, 74) comporte une surface d'étanchéité d'extrémité (42b, 72b)
qui est en contact glissant relatif avec le plateau d'extrémité (36a) de l'autre volute
(36) et une surface de contact glissant (42c, 72c) qui est reliée perpendiculairement
à un bord latéral de la surface d'étanchéité d'extrémité (42b, 72b) et qui est située
relativement à la première surface de paroi à une distance correspondant au fin interstice
(G).
4. Machine fluidique à volute (1) conforme à la revendication 2, dans laquelle les broches
(42a) et les orifices de réception de broches (46a) forment des moyens de retenue
de la lamelle d'étanchéité (42, 72, 74) à l'extrémité de la paroi de volute (36b,
38b).
5. Machine fluidique à volute (1) conforme à la revendication 4, dans laquelle les moyens
de retenue comportent en outre une couche adhésive.
6. Machine fluidique à volute (1) conforme à la revendication 1, dans laquelle la lamelle
d'étanchéité (42, 72, 74) est réalisée en un matériau choisit dans le groupe formé
par les résines du groupe des poly phénylène sulfures, les résines du groupe des polyéther
cétones, et les résines du groupe des poly-imides.
7. Machine fluidique à volute (1) conforme à la revendication 1, comportant en outre
un moteur, l'unité de volutes (35) étant montée à chaque extrémité de l'arbre rotatif
de ce moteur.