Note: Descriptions are shown in the official language in which they were submitted.
CA 02787308 2012-07-17
1
DESCRIPTION
FLUID MACHINE
Technical Field
[0001] This invention relates to a fluid machine,
specifically a fluid machine suited to form a hermetic
reciprocating compressor compressing carbon-dioxide
refrigerant.
Background Art
[0002] There is known a hermetic compressor which
belongs to this class of fluid machine and which comprises
an electric motor and a compressing mechanism arranged in a
hermetic container such that drive power is transmitted
from the electric motor to the compressing mechanism to
compress a refrigerant.
Patent document 1 discloses a hermetic container
composed of three members: a center, a top and a bottom
shells, the center shell being a steel tube open at each
end, and the top and bottom shells being cup-shaped cast
members welded to each open end of the center shell.
[0003] Patent document 2 discloses a hermetic container
composed of two press-formed members: top and bottom shells,
and patent document 3 discloses a hermetic container
composed of two forged members: top and bottom shells.
Prior-art Document
Patent Document
[0004] Patent document 1: Japanese Patent Application
Laid-open No. 2006-177285
Patent document 2: Japanese Patent Publication No. Sho
58-19869
CA 02787308 2012-07-17
2
Patent document 3: Japanese Patent Application Laid-
open No. 2004-285927
Summary of the Invention
Problem to be Solved by the Invention
[0005] The aforementioned hermetic containers are each
constructed by welding the shells together. In the
hermetic container disclosed in patent document 1, however,
the top and bottom shells are cast products, and thus,
difficult to weld together and likely to produce poor welds,
since cast products have generally a high carbon content.
Further, the center shell in the form of a steel tube
incurs high material costs. Furthermore, the hermetic
container composed of three members requires welding at two
locations or more, resulting in correspondingly-increased
assembly manhours, and thus, increased cost of producing
the hermetic container, and thus, the compressor.
[0006] The hermetic container composed of two shells, as
seen in patent documents 2 and 3, requires welding at fewer
locations, and thus, less assembly manhours, leading to a
reduced cost of producing the hermetic container. Further,
the press-formed or forged shells are expected to alleviate
the aforementioned problem of poor welds.
However, press-forming only allows the shells to have
a simple shape such as a dome shape, and portions for the
electric motor, the compressing mechanism and others to be
fixed to need to be created in the shells by additional
working, leading to an increase in cost of producing the
hermetic container.
[0007] Forging allows the shells to have a complicated
shape as needed. The shells forged, however, tend to have
a great wall thickness, and thus, a great weight compared
with the shells press-formed, preventing the hermetic
CA 02787308 2012-07-17
3
container, and thus, the fluid machine from having a
reduced weight and size.
The present invention has been made in view of the
above problems. An object of the present invention is to
provide a fluid machine which can be produced with a
reduced weight and size at a reduced production cost.
Means for Solving the Invention
[0008] In order to achieve the above object, a fluid
machine according to the present invention comprises a
drive unit and a driven unit arranged in a hermetic
container such that drive power is transmitted from the
drive unit to the driven unit, the hermetic container
including a first shell covering the drive unit and a
second shell covering the driven unit and joined to the
first shell, wherein the first and second shells are
members formed by different working processes (claim 1).
[0009] Specifically, the first and second shells may be
a forged and a press-formed members, respectively (claim 2),
or vice versa (claim 3).
The fluid machine may be configured such that the
drive unit is arranged in the first shell with its length
aligned with a depth of the first shell, while the driven
unit is arranged in the second shell with its length
aligned with a diameter of the second shell (claim 4).
The second shell may have a holding portion by which
to hold the second shell during forging of the second shell,
the holding portion forming a crest of the second shell
projecting outward in a central region radially away from a
side wall of the second shell (claim 5).
[0010] The second shell may have a lubricating system
configured to supply a lubricant collecting in an inner
bottom portion of the second shell to sliding parts of the
CA 02787308 2012-07-17
4
drive unit and of the driven unit, wherein said inner
bottom portion is a recess defined by an inner side of said
holing portion and having a shape approximately similar to
an outer shape of said holding portion and serving as an
oil reservoir (claim 6).
The second shell may have a support portion for the
drive unit and the driven unit to be fixed to (claim 7).
[0011] The holding portion, the oil reservoir and the
support portion may be parts formed all at once when the
second shell is forged (claim 8).
The hermetic container may undergo pressure exerted by
a working fluid sucked in and discharged from the driven
unit, the working fluid being carbon-dioxide refrigerant
(claim 9).
Effect of the Invention
[0012] The fluid machine according to the present
invention recited in claim 1 comprises a hermetic container
composed of two shells, namely first and second shells,
wherein at least either the first or the second shell has a
reduced wall thickness since it is formed by press-forming.
As a result, the hermetic container, and thus, the fluid
machine have a reduced weight and size.
Specifically, in the fluid machine recited in claim 2,
at least the second shell, which is press-formed, has a
reduced wall thickness, and in the fluid machine recited in
claim 3, at least the first shell, which is press-formed,
has a reduced wall thickness. In either type of the fluid
machine, the shell formed not by forging is unlikely to
produce a poor weld when welded to the other shell. The
hermetic container has thus an increased weld strength.
[0013] In the fluid machine recited in claim 4, the
first shell is formed by press-forming to have a depth
CA 02787308 2012-07-17
corresponding to the length of the drive unit, and the
second shell is formed by forging to have a diameter
corresponding to the length of the driven unit.
Specifically, the first shell, requiring a great depth
5 compared with the second shell, can be easily formed by
press-forming into a shape corresponding to the outer shape
of the drive unit, with a reduced wall thickness.
[0014] The second shell, not requiring a great depth
compared with the first shell, can be easily formed by
forging into a shape corresponding to the outer shape of
the driven unit, with a reduced wall thickness. This
ensures that the hermetic container, and thus, the fluid
machine have a reduced weight and size. Further, this
allows a reduction of dead space within the hermetic
container, leading to a further reduced size of the fluid
machine.
In the fluid machine recited in claim 5, the holding
portion provided to form the crest of the second shell
saves the second shell from having an unprofitably-great
wall thickness at the side and/or the crest, which would be
inevitable when the holding portion is provided at the side
of the bottom shell. This leads to a further reduced
weight and size of the hermetic container, and thus of the
compressor.
[0015] In the fluid machine recited in claim 6, the
provision of the holding portion not only allows a
reduction in wall thickness of the second shell but also
facilitates provision of an inner bottom portion serving as
an oil reservoir, without requiring a separate member such
as an oil pan. The inner bottom portion serving as an oil
reservoir can hold the lubricant to have an oil surface at
a specified level. This ensures that the lubricant is
smoothly supplied to the sliding parts through the
CA 02787308 2012-07-17
6
lubricating system and efficiently circulates within the
hermetic container, even though the amount of the lubricant
collecting in the inner bottom portion is small.
[0016] In the fluid machine recited in claim 7, the
drive and driven units are easily fixed without requiring
another member such as a frame.
In the fluid machine recited in claim 8, the holding
portion, the oil reservoir and the support portion are
easily formed without requiring another member or another
working process, which means that the fluid machine can be
produced with an increased productivity.
When the working fluid is carbon-dioxide refrigerant,
the working fluid is discharged from the driven unit at
very high pressure. The inner side of the hermetic
container can therefore be subjected to very high pressure,
and thus, normally, the hermetic container cannot avoid
having a great thickness and weight for safety's sake. The
hermetic container and fluid machine structured as
described above, which allow effective reduction of weight
and size, are therefore favorable.
Brief Description of the Drawings
[0017] FIG. 1 is a vertical cross-sectional view of a
compressor, a first embodiment of the present invention.
FIG. 2 is an enlarged view showing a relevant part of
a compressing mechanism shown in FIG. 1,
FIG. 3 is a diagram showing the outer shape of a
hermetic container of the compressor shown in FIG. 1, and
FIG. 4 is a perspective view showing a bottom shell
shown in FIG. 3, viewed from above.
Best Mode of Carrying out the Invention
[0018] FIGS. 1 to 4 show a compressor 1, a first
CA 02787308 2012-07-17
7
embodiment of fluid machine.
The compressor 1 is a hermetic reciprocating
compressor, which belongs to the class of positive-
displacement compressors called reciprocating compressors
or piston compressors and which is incorporated into, for
example an automatic vending machine to constitute a
refrigeration cycle circuit, not shown.
The refrigeration cycle circuit has a circulation path
along which a refrigerant, or working fluid of the
compressor 1 circulates. The refrigerant is for example
carbon dioxide, which is a non-combustible natural
refrigerant.
[0019] As seen in FIG. 1, the compressor 1 comprises a
hermetic container 2 enclosing an electric motor (drive
unit) 4 and a compressing mechanism (driven unit) 6, the
latter being supplied with drive power from the former.
The electric motor 4 comprises a stator 8 supplied
with current to generate a magnetic field, and a rotor 10
rotating in the magnetic field generated by the stator 8.
The rotor 10 is arranged within the stator 8, coaxially,
and fixed on a main shaft portion 24 of a crankshaft 14,
described later, by heat-fitting. Current is supplied to
the stator 8 from outside the compressor 1 via electric
components 12 fixed to the hermetic container 2 and leads,
not shown.
[0020] The compressing mechanism 6 is composed of a
crankshaft 14, a cylinder block 16, a piston 18, a
connecting rod 20 and others. The crankshaft 14 includes
an eccentric shaft portion 22 and a main shaft portion 24.
As seen in FIG. 2, the cylinder block 16 has a
cylinder bore 26. A cylinder gasket 28, a suction valve 50,
described later, a valve plate 30, a head gasket 32 and a
cylinder head 34, arranged in this order, are fastened to
CA 02787308 2012-07-17
8
the cylinder block 16 with bolts to close an entrance to
the cylinder bore 26.
[0021] As seen in FIG. 1, the stator 8 is bolted to the
cylinder block 16 with a frame 36 between, the frame 36
being joined to the hermetic container 2.
Specifically, the frame 36 includes a lower base
portion 38 joined to the hermetic container 2 and
supporting the electric motor 4 and the compressing
mechanism 6, and an upper cylindrical portion 40 with a
bearing 42 arranged on an inner circumferential face 40a
and a bearing 44 on a top face 40b. The bearing 42
supports the main shaft portion 24, and the bearing 44 in
the form of a thrust race (bearing), a thrust washer or the
like supports a thrust load generated by the rotor 10.
[0022] As seen in FIG. 2, the valve plate 30 has a
refrigerant suction hole 46 and a refrigerant discharge
hole 48 opened and closed by a suction valve 50 and a
discharge valve 52, respectively. The suction and
discharge valves are reed valves.
The cylinder head 34 has a refrigerant suction chamber
54 and a refrigerant discharge chamber 56. In the
compression stroke of a piston 18, the discharge valve 52
opens to allow a flow from the cylinder bore 26 to the
discharge chamber 56 through the discharge hole 48. In the
suction stroke of the piston 18, the suction valve 50 opens
to allow a flow from the suction chamber 54 to the cylinder
bore 26 through the suction hole 46.
[0023] A suction pipe 58 and a discharge pipe 60 are
fitted to the hermetic container 2. The suction and
discharge pipes 58, 60 connect to the suction and discharge
chambers 54, 56 in the cylinder head 34, at an end,
respectively, and to the refrigeration cycle circuit at the
other end. Suction and discharge mufflers, not shown, are
CA 02787308 2012-07-17
9
incorporated in the suction and discharge pipes to reduce
pulsation and noise of the refrigerant flowing therein.
[0024] The connecting rod 20 has a large end portion 62
connected to the eccentric shaft portion 22 of the
crankshaft 14 in a manner allowing rotating motion of the
crankshaft, and an opposite small end portion connected to
the piston 18 in a manner allowing reciprocating motion of
the piston. The small end portion 64 is connected to the
piston 18 by a piston pin 66, which is prevented from
coming off the piston 18 by a fixing pin 68.
[0025] As the crankshaft 14 rotates, eccentric rotation
of the eccentric shaft portion 22 makes the connecting rod
swing on the piston pin 66, which in turn makes the
piston 18 reciprocate within the cylinder bore 26.
15 The inside of the hermetic container 2 is mostly
subjected to refrigerant discharge pressure. A lubricant
lubricating sliding parts of the electric motor 4 and of
the compressing mechanism 6, such as the bearings 42, 44,
collects in an inner bottom portion 2a of the hermetic
20 container 2 in a small amount.
[0026] The crankshaft 14 has an oil passage (lubricating
system) 70 extending approximately from the shaft center at
the bottom 22a of the eccentric shaft portion 22 to the
middle of the main shaft portion 24. The oil passage 70
has an upper end open at the outer circumferential face 24a
of the main shaft portion 24 and a lower end connected to
an oil pipe (lubricating system) 72. The oil pipe 72
includes a lower slant portion 74 slanting in a manner
approaching the shaft center of the main shaft portion 24
approximately from the shaft center of the eccentric shaft
portion 22. The slant portion 74 of the oil pipe 72
extends downward into an inner bottom portion 2a of the
hermetic container 2 in the shape of a recess, the inner
CA 02787308 2012-07-17
bottom portion 2a thus serving as an oil reservoir 76.
[0027] The oil reservoir 76 has an area and a depth
ensuring that a small amount of the lubricant, more or less
200 cc, for example, has an oil surface at the level of the
5 lower end of the oil pipe 74 or above. As the crankshaft
14 rotates, the oil pipe 72 eccentrically rotates with the
eccentric shaft portion 22, resulting in the lubricant
moving up the oil passage 74 from the oil reservoir 76 by
centrifugal force acting on the lubricant in the slant
10 portion 74 of the oil pipe 72 in the obliquely in- and
upward direction.
[0028] The operation and action of the compressor 1 will
be described below.
The compressor 1 is designed such that as the stator 8
is supplied with current, the rotor 10 fixed on the main
shaft portion 24 rotates, and thus, the crankshaft 14
rotates, which in turn makes the piston 18 reciprocate
within the cylinder bore 18 by means of the connecting rod
20. As the piston 18 reciprocates, the refrigerant is
sucked into the cylinder bore 26 from the refrigeration
cycle circuit, compressed in the cylinder bore 26 and
discharged from the cylinder bore to the refrigeration
cycle circuit.
[0029] Specifically, the piston 18 moves in the
direction decreasing the volume of the cylinder bore 26, so
that the refrigerant is compressed within the cylinder bore
26. When the pressure in the cylinder bore 26 exceeds
refrigerant discharge pressure, the discharge valve 52
opens because of pressure difference between the cylinder
bore 26 and the discharge chamber 56. The refrigerant
compressed thus flows from the cylinder bore into the
discharge chamber 56 through the discharge hole 48, and
then to the refrigeration cycle circuit through the
CA 02787308 2012-07-17
11
discharge pipe 60.
[0030] After reaching the top dead center, the piston 18
moves in the direction increasing the volume of the
cylinder bore 26, and thus, the pressure in the cylinder
bore 26 decreases and the discharge valve 50 closes because
of pressure difference between the cylinder bore 26 and the
discharge chamber 56.
When the pressure in the cylinder bore 26 decreases to
refrigerant suction pressure or below, the suction valve
opens 50 because of pressure difference between the
cylinder bore 26 and the suction chamber 54. The
refrigerant thus flows into the suction chamber 54 through
the suction pipe 58, and then into the cylinder bore 56
through the suction hole 46.
[0031] After reaching the bottom dead center, the piston
18 moves in the direction decreasing the volume of the
cylinder bore 26, and thus, the refrigerant is again
compressed within the cylinder bore 26. The process of
sucking the refrigerant from the refrigeration cycle
circuit into the cylinder bore 26, compressing it within
the cylinder bore 26 and discharging it from the cylinder
bore to the refrigeration cycle circuit is repeated this
way.
[0032] The above-described operation of the compressor 1
makes the lubricant move from the oil reservoir 76 up into
the oil passage 70, then flow out of the oil passage 70
down toward the eccentric shaft portion 22, thus
lubricating parts including the large end portion 62, and
splash over the piston by centrifugal force, thus
lubricating parts including a skirt portion 18 of the
piston 18.
[0033] Part of the lubricant flows out of the oil
passage 70 and moves upward along a groove in the
CA 02787308 2012-07-17
12
circumferential face of the crankshaft 14, not shown, by
centrifugal force, thereby forming an oil film between the
crankshaft 14 and the frame 36, thus lubricating the
bearing 42, and moves further up toward the top of the
crankshaft 14. After reaching the top face 40b of the
cylindrical portion 40 and lubricating the bearing 44, the
lubricant flows down into the oil reservoir 76 by gravity.
The part of the lubricant not passing over the bearing 44
moves further up the inner wall surface 10a of the rotor 10
to reach the top of the rotor 10, and splashes accompanying
the rotation of the rotor 10, by centrifugal force, thus
cooling the stator 8, and falls into the oil reservoir 76
by gravity.
[0034] While lubricating the parts including the skirt
portion 18a of the piston 18, part of the lubricant is
sucked into the cylinder bore 26 in the form of oil mist,
which flows into a space between the piston 18 and the
cylinder block 18 together with a refrigerant gas leaking
from the cylinder bore 26, thus sealing and lubricating the
piston 18 and the cylinder block. The lubricant adhering
to the wall surface 54a of the suction chamber 54 falls
into the oil reservoir 76 by gravity. The lubricant
falling into the oil reservoir 76 again moves up through
the oil pipe 72. The lubricant thus circulates within the
hermetic container 2, lubricating and sealing the sliding
parts of the electric motor 4 and of the compressing
mechanism 6.
[0035] In the present embodiment, as seen also from FIG.
3, the hermetic container 2 is a shell structure composed
of two shells: a top shell (first shell) 78 covering the
electric motor 4 and a bottom shell (second shell) 80
covering the compressing mechanism 6. Within the hermetic
container 2, the crankshaft 14 and the connecting rod 20
CA 02787308 2012-07-17
13
need to be arranged at right angles to each other, and thus,
the electric motor 4 is arranged in the top shell 78 with
its length aligned with the depth of the top shell, while
the compressing mechanism 6 is arranged in the bottom shell
80 with its length aligned with a diameter of the bottom
shell 80. The top shell 78 has therefore a great depth
compared with the bottom shell 80.
[0036] The shells 78, 80 each have a root edge at their
rims 78a, 80a so that the root edges mated form a groove 82.
The shells 78, 80 are joined together by forming a weld 84
in the form a continuous series of beads in the groove 82
over its entire length, by a single step of welding. In
other words, the shells are joined together by a single
butt weld joint formed by a single step of welding.
[0037] The top shell 78 is formed by press-forming, more
specifically deep-drawing a soft steel, such as SPCC or
SPHE, into a simple shape like a dome. The top shell 78 is
formed as thin as possible, specifically into a thickness
of more or less 6.8mm at the thinnest portion and more or
less 7mm even at thick portions. Work hardening during
deep drawing provides a sufficient resistance to high
pressure exerted by the refrigerant.
The bottom shell 80, on the other hand, is formed by
forging a soft steel, such as S20C or S25C. The bottom
shell 80 is formed as thin as possible, specifically into a
thickness of more or less 8.5mm. Like the top shell 78,
the bottom shell has a sufficient resistance to high
pressure exerted by the refrigerant on the hermetic
container 2.
[0038] The bottom shell 80 includes a holding portion 86
by which to hold the bottom shell 80 during forging of the
bottom shell 80. The holding portion 86 forms a crest 80c
of the bottom shell 80 projecting outward in a central
CA 02787308 2012-07-17
14
region radially away from a side 80b of the bottom shell 80.
The inner bottom portion 2a serving as the oil reservoir 76
is a recess defined by the inner side of the holding
portion 86 and having a shape similar to the outer shape of
the holding portion 86. The bottom shell 80 has thus an
approximately uniform wall thickness throughout the side
80b and the crest 80a.
[0039] A base plate 88 is fitted around the crest 80a,
or holding portion 86 to allow the compressor 1 to be
installed stably. Attaching a rubber vibration insulator or
the like, not shown, to the underside of the base plate 88
ensures that the compressor 1 is fixed with vibration being
reduced during operation.
The bottom shell 80 has four support portions 90
bulging radially-inward from the rim 80a and describing an
undulating outline. The frame 36 supporting the stator 8
and the cylinder block 16, as seen in FIG. 1, is fixed to
these support portions 4. Although not shown, the hermetic
container 2 may have another support structure allowing the
stator 8 and the cylinder block 16 to be fixed directly to
the support portions without a frame 36.
[0040] The holding portion 86, the oil reservoir 76 and
the support portions 90 of the bottom shell 80 are formed
all at once when the bottom shell 80 is forged.
The above-described compressor 1 presented as a first
embodiment of the present invention has a hermetic
container 2 composed of two shells 78, 80, wherein at least
the press-formed top shell 78 has a reduced wall thickness,
resulting in a reduced weight and size of the hermetic
container 2, and thus, of the compressor 1.
The top shell 78 formed not by forging is unlikely to
produce a poor weld when welded to the bottom shell 80,
resulting in an increased weld strength of the hermetic
CA 02787308 2012-07-17
container.
[0041] The top shell 78 is press-formed to have a depth
corresponding to the length of the electric motor 4, while
the bottom shell 80 is forged to have a diameter
5 corresponding to the length of the compressing mechanism 8.
Specifically, the top shell 78, requiring a great depth
compared with the bottom shell 80, can be easily formed by
press-forming into a shape corresponding to the outer shape
of the electric motor 4, with a reduced wall thickness.
10 [0042] The bottom shell 80, not requiring a great depth
compared with the top shell 78, can be easily formed by
forging into a shape corresponding to the outer shape of
the compressing mechanism 6, with a reduced wall thickness.
This ensures that the hermetic container 2, and thus, the
15 compressor 1 have a reduced weight and size. Further, this
allows a reduction of dead space within the hermetic
container 2, leading to a further reduced size of the
compressor 1.
[0043] The holding portion 86 provided to form the crest
of the bottom shell 80 saves the bottom shell 80 from
having an unprofitably-great wall thickness at the side 80b
and/or the crest 80c, which would be inevitable when the
holding portion 83 is provided at the side 80b of the
bottom shell 80. This leads to a further reduced weight
and size of the hermetic container 2, and thus of the
compressor 1.
The provision of the holding portion 86 not only
allows a reduction in wall thickness of the bottom shell 80
but also facilitates provision of an inner bottom portion
2a serving as an oil reservoir 76, without requiring a
separate member such as an oil pan. The inner bottom
portion 2a serving as an oil reservoir 78 can hold the
lubricant to have an oil surface at a specified level.
CA 02787308 2012-07-17
16
This ensures that the lubricant is smoothly supplied to the
sliding parts of the electric motor 4 and of the
compressing mechanism through the lubricating system
including the oil pipe 72 and the oil passage 70 and
efficiently circulates within the hermetic container 2,
even though the amount of the lubricant collecting in the
inner bottom portion 2a is small.
[0044] If the hermetic container 2 has a support
structure allowing the stator 8 and the cylinder block 16
to be fixed directly to the support portions 90 without
requiring a frame 36, the electric motor 4 and the
compressing mechanism 6 are easily fixed without requiring
a separate member such as a frame 36.
The holding portion 86, the oil reservoir 76 and the
support portions 90 are formed all at once when the bottom
shell 80 is forged. In other words, these parts can be
easily formed without requiring another member or another
working process, which means that the compressor 1 can be
produced with an increased productivity.
[0045] The present invention is not restricted to the
above-described embodiment, which can be modified in
various ways.
Specifically, although in the described embodiment,
the top shell 78 is press-formed and the bottom shell 80 is
forged, the shells 78, 80 may be formed in another way.
What is essential is that the shells 78, 80 be formed by
different working processes allowing them to have a reduced
wall thickness, and thus, allowing the hermetic container 2,
and thus, the compressor 1 to have a reduced weight and
size. The described embodiment may be modified such that
the top shell 78 is forged and the bottom shell 80 is
press-formed, for example.
[0046] In the present embodiment of compressor 1, the
CA 02787308 2012-07-17
17
working fluid is carbon-dioxide refrigerant. The working
fluid is however not restricted to carbon-dioxide
refrigerant. When the working fluid is carbon-dioxide
refrigerant, the working fluid is discharged from the
compressing mechanism 8 in a supercritical state, and thus,
at very high pressure. The inner side of the hermetic
container 2 can therefore be subjected to very high
pressure, and thus, normally, the hermetic container 2
cannot avoid having a great thickness and weight for
safety's sake. The hermetic container 2 and compressor 1
structured as described above, which allow effective
reduction of weight and size, are therefore favorable.
[0047] Although the present embodiment is a positive-
displacement compressor 1, the present invention is
applicable to hermetic fluid machines in general, including
scroll compressors and expanders. Needless to say, fluid
machines to which the present invention is applied can be
used to constitute a refrigeration cycle circuit
incorporated in apparatuses other than vending machines.
Explanation of the Reference Characters
[0048] 1 Compressor (fluid machine)
2 Hermetic container
2a Inner bottom portion
4 Electric motor (drive unit)
6 Compressing mechanism (driven unit)
70 Oil passage (lubricating system)
72 Oil pipe (lubricating system)
76 Oil reservoir
78 Top shell (first shell)
80 Bottom shell (second shell)
80a Side
80c Crest
CA 02787308 2012-07-17
18
86 Holding portion
90 Support portion
