FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
METHOD FOR MANUFACTURING HERMETIC COMPRESSOR;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND
EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 1008310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION
AND THE MANNER IN WHICH IT IS TO BE PERFORMED

2
DESCRIPTION
Technical Field
[0001]
5 The present disclosure relates to a method for manufacturing a hermetic
compressor including a hermetic casing housing, inside thereof, a spring configured
to push a vane.
Background Art
[0002]
10 A compression mechanism part of a hermetic rotary compressor includes a
cylinder having, inside thereof, a space serving as a compression chamber, a vane
provided in a groove formed in the cylinder so as to slide, the vane partitioning the
space, and a spring configured to push the vane toward the space. In the hermetic
rotary compressor, the compression mechanism part is housed in a hermetic casing.
15 Typically, the hermetic casing includes a casing body having a substantially
cylindrical shape. In the conventional hermetic rotary compressor, the cylinder, the
vane, and the spring are housed in the casing body.
[0003]
With increasing stroke volume of hermetic rotary compressors in recent years,
20 an installation space for a spring may be reduced, which may make it difficult to leave
sufficient room for the spring to extend and contract. In view of this, some of the
conventional hermetic rotary compressors include a hermetic casing provided with a
projecting casing, and a part of the spring is housed in the projecting casing (e.g.,
refer to Patent Literature 1). Specifically, the projecting casing is welded to the
25 casing body and projects outward from the casing body. The cylinder and the vane
are housed in the casing body. A part of the spring is housed in the casing body,
and the rest part of the spring is housed in the projecting casing. Accordingly, as
compared to the configuration in which the entire spring is housed in the casing body,
it is possible to leave a large installation space for the spring and leave sufficient
30 room for the spring to extend and contract.

Citation List
Patent Literature
[0004]
Patent Literature 1: Japanese Unexamined Patent Application Publication No.
5 63-16189
Summary of Invention
Technical Problem
[0005]
When the casing body and the projecting casing of the hermetic casing are
10 joined together by resistance welding, a pair of electrodes holds the casing body and
the projecting casing therebetween and applies pressure to the casing body and the
projecting casing, and, in this state, an electric current is conducted between the pair
of electrodes to weld a contact area between the casing body and the projecting
casing. However, the electric current at the contact area between the casing body
15 and the projecting casing decreases because the distance between the pair of
electrodes holding the casing body and the projecting casing therebetween is long.
Thus, in the conventional hermetic compressor provided with the hermetic casing
including the projecting casing, when the casing body and the projecting casing are
joined together by resistance welding, poor welding may occur at the contact area
20 between the casing body and the projecting casing. As a result, in the conventional
hermetic compressor provided with the hermetic casing including the projecting
casing, the airtightness at the joint between the casing body and the projecting casing
may decrease, which may disadvantageously cause leakage of refrigerant through
the joint between the casing body and the projecting casing.
25 [0006]
The present disclosure has been made to solve the above problem, and an
object thereof is to propose a method for manufacturing a hermetic compressor that
can more reliably prevent reduction in the airtightness at the joint between the casing
body and the projecting casing than the conventional method can.
30 Solution to Problem

[0007]
A method for manufacturing a hermetic compressor according to an
embodiment of the present disclosure is a method for manufacturing a hermetic
compressor, the hermetic compressor including a hermetic casing housing a cylinder
5 having, inside thereof, a space serving as a compression chamber, a vane provided
in a groove formed in the cylinder so as to slide, the vane partitioning the space, and
a spring configured to push the vane toward the space, the hermetic casing including
a casing body housing the cylinder and the vane, and a projecting casing welded to
the casing body, projecting outward from the casing body, and housing a part of the
10 spring. The method includes: holding the casing body and the projecting casing
between a first electrode in contact with the projecting casing and a second electrode
in contact with the casing body; and conducting an electric current between the first
electrode and the second electrode with an energization auxiliary jig made of a
material having a higher conductivity than a material of the projecting casing kept in
15 contact with an outer periphery of the projecting casing to join the casing body and
the projecting casing together by resistance welding.
Advantageous Effects of Invention
[0008]
In the method for manufacturing the hermetic compressor according to an
20 embodiment of the present disclosure, the electric current flowing between the first
electrode and the casing body mainly flows through the energization auxiliary jig
made of the material having a higher conductivity than the material of the projecting
casing in an area where the energization auxiliary jig is present. The electric current
flowing between the first electrode and the casing body flows through the projecting
25 casing in an area where the energization auxiliary jig is not present. Thus, the
method for manufacturing the hermetic compressor according to an embodiment of
the present disclosure can reduce, in a path for the electric current flowing between
the first electrode and the casing body, the length of a part of the path passing
through the projecting casing. Thus, the method for manufacturing the hermetic
30 compressor according to an embodiment of the present disclosure can more reliably

prevent decrease in the current at the contact area between the casing body and the
projecting casing than the conventional method can. Therefore, the method for
manufacturing the hermetic compressor according to an embodiment of the present
disclosure can more reliably prevent the occurrence of poor welding at the contact
5 area between the casing body and the projecting casing than the conventional
method can and more reliably prevent reduction in the airtightness at the joint
between the casing body and the projecting casing than the conventional method
can.
Brief Description of Drawings
10 [0009]
[Fig. 1] Fig. 1 is a longitudinal sectional view of a hermetic compressor
according to an embodiment.
[Fig. 2] Fig. 2 is a cross sectional view of a hermetic casing according to the
embodiment.
15 [Fig. 3] Fig. 3 is a diagram for describing a method for joining a casing body
and a projecting casing together by conventional resistance welding.
[Fig. 4] Fig. 4 is a flow chart for describing a method for joining the casing body
and the projecting casing together by resistance welding according to the
embodiment.
20 [Fig. 5] Fig. 5 is a diagram illustrating the projecting casing of the hermetic
compressor according to the embodiment with an energization auxiliary jig attached
thereto.
[Fig. 6] Fig. 6 is a sectional view taken along line A-A of Fig. 5.
[Fig. 7] Fig. 7 is a diagram for describing the method for joining the casing body
25 and the projecting casing together by the resistance welding according to the
embodiment.
Description of Embodiments
[0010]
Embodiment.
30 Fig. 1 is a longitudinal sectional view of a hermetic compressor according to an

embodiment. Fig. 2 is a cross sectional view of a hermetic casing according to the
embodiment. Note that Fig. 2 is a cross sectional view of a hermetic compressor
100 taken at the position of a compression mechanism part 20.
The hermetic compressor 100 according to the present embodiment is a rotary
5 compressor and includes an electric motor 1, the compression mechanism part 20,
and a driving shaft 10. The driving shaft 10 connects the electric motor 1 and the
compression mechanism part 20 to each other. The hermetic compressor 100
according to the present embodiment further includes a hermetic casing 30. The
electric motor 1, the compression mechanism part 20, and the driving shaft 10 are
10 housed in the hermetic casing 30.
[0011]
The electric motor 1 includes a stator 2 fixed to the hermetic casing 30, and a
rotor 3 configured to be rotated by magnetic force generated by the stator 2.
[0012]
15 The driving shaft 10 is connected to the rotor 3 of the electric motor 1 and the
compression mechanism part 20, and transmits the driving force of the electric motor
1 to the compression mechanism part 20. The driving shaft 10 includes a main shaft
part 11, and an eccentric part 12 provided partway of the main shaft part 11. The
main shaft part 11 and the eccentric part 12 each have a columnar shape. The
20 central axis of the eccentric part 12 is eccentric relative to the central axis of the main
shaft part 11. That is, when the main shaft part 11 rotates, the eccentric part 12
eccentrically rotates. The main shaft part 11 is fixed to the rotor 3 of the electric
motor 1. A rolling piston 22 having a cylindrical shape is attached to the outer
periphery of the eccentric part 12 so as to slide. The rolling piston 22 is a constituent
25 component of the compression mechanism part 20.
[0013]
The compression mechanism part 20 compresses low-pressure refrigerant
suctioned into the compression mechanism part 20 using the driving force of the
electric motor 1 transmitted from the driving shaft 10 and discharges high-pressure
30 refrigerant into the hermetic casing 30. The compression mechanism part 20

includes a cylinder 21, the rolling piston 22, a vane 23, a first bearing part 24, a
second bearing part 25, and a spring 26.
[0014]
The cylinder 21 has, inside thereof, a space serving as a compression chamber
5 21a. Specifically, the space inside the cylinder 21 is partitioned by the vane 23 into
a part serving as the compression chamber 21a and a part serving as a suction
chamber 21b. The space inside the cylinder 21 has a cylindrical shape. The
central axis of the space is aligned with the central axis of the main shaft part 11 of
the driving shaft 10. The rolling piston 22 is disposed in the space. Thus, when the
10 driving shaft 10 rotates, inside the space inside the cylinder 21, the eccentric part 12
and the rolling piston 22 eccentrically rotate relative to the central axis of the space.
An upper opening of the space inside the cylinder 21 is closed with the first bearing
part 24. A lower opening of the space inside the cylinder 21 is closed with the
second bearing part 25. The first bearing part 24 and the second bearing part 25
15 support the main shaft part 11 of the driving shaft 10 so that the main shaft part 11
can rotate.
[0015]
The cylinder 21 has a groove 21c extending in the radial direction of the
cylinder 21. One end of the groove 21c communicates with the space inside the
20 cylinder 21. The other end of the groove 21c is open on the outer periphery of the
cylinder 21. The vane 23 is provided in the groove 21c so as to slide.
[0016]
The spring 26 is attached to an end 23a of the vane 23. An end 26a of the
spring 26 is fixed. Specifically, in the present embodiment, a part of the spring 26
25 including the end 26a is housed in a spring guide 27 having, for example, a tubular
shape. The end 26a of the spring 26 is fixed to the spring guide 27. The spring
guide 27 is fixed to the outer periphery of the cylinder 21. An end 26b of the spring
26 compressed to have a length shorter than its natural length is in contact with the
end 23a of the vane 23. That is, the spring 26 pushes the vane 23 toward the rolling
30 piston 22. In other words, the spring 26 pushes the vane 23 toward the space inside

the cylinder 21.
[0017]
Accordingly, even when the eccentric part 12 and the rolling piston 22
eccentrically rotate inside the space inside the cylinder 21, the end 23b of the vane 23
5 can be kept in contact with the outer peripheral face of the rolling piston 22. That is,
even when the eccentric part 12 and the rolling piston 22 eccentrically rotate inside
the space inside the cylinder 21, the space inside the cylinder 21 can be kept
partitioned by the vane 23 into the suction chamber 21b and the compression
chamber 21a.
10 [0018]
The cylinder 21 has a suction port 21d communicating with the suction
chamber 21b. One end of a suction pipe 40 is connected to the suction port 21d.
The other end of the suction pipe 40 is connected to an accumulator 41 configured to
reduce refrigerant noise. The cylinder 21 has a discharge port 21e communicating
15 with the compression chamber 21a. The discharge port 21e also communicates with
the inside of the hermetic casing 30 through a discharge port (not illustrated) formed
in the first bearing part 24.
[0019]
As the rolling piston 22 eccentrically rotates inside the cylinder 21, the volume
20 of the suction chamber 21b increases. Accordingly, low-pressure refrigerant from
the outside of the hermetic compressor 100 passes through the accumulator 41, the
suction pipe 40, and the suction port 21d, and flows into the suction chamber 21b.
When the rolling piston 22 further eccentrically rotates inside the cylinder 21, the
communication between the suction chamber 21b and the suction port 21d is
25 blocked. At this time, the space that has been serving as the suction chamber 21b
starts serving as the compression chamber 21a.
[0020]
As the rolling piston 22 eccentrically rotates inside the cylinder 21, the volume
of the compression chamber 21a decreases. Accordingly, refrigerant inside the
30 compression chamber 21a is compressed to become high-pressure refrigerant and

discharged into the hermetic casing 30 through the discharge port 21e and the
discharge port (not illustrated) of the first bearing part 24. The high-pressure
refrigerant discharged into the hermetic casing 30 flows out of the hermetic
compressor 100 through a discharge pipe 39 communicating with the inside of the
5 hermetic casing 30. When the rolling piston 22 further eccentrically rotates inside
the cylinder 21, the communication between the compression chamber 21a and the
discharge port 21e is blocked. At this time, the space that has been serving as the
compression chamber 21a starts serving as the suction chamber 21b.
[0021]
10 The hermetic casing 30 according to the present embodiment includes a casing
body 31 and a projecting casing 35. The casing body 31 has a substantially
cylindrical shape. In the present embodiment, the casing body 31 includes an upper
casing 32, a middle casing 33, and a lower casing 34. The middle casing 33 is a
part having a substantially tubular shape. The upper casing 32 is a part closing an
15 upper opening of the middle casing 33. The lower casing 34 is a part closing a lower
opening of the middle casing 33.
[0022]
The projecting casing 35 has a main body 36 having a substantially tubular
shape. The projecting casing 35 projects outward from the casing body 31 with an
20 end 36a of the main body 36 welded to the casing body 31. In the present
embodiment, the end 36a of the main body 36 of the projecting casing 35 is welded to
the middle casing 33. The middle casing 33 has a through hole 33a at a position
corresponding to the end 36a of the main body 36 of the projecting casing 35. Thus,
the inside of the casing body 31 and the inside of the projecting casing 35
25 communicate with each other through the through hole 33a. An end 36b of the main
body 36 of the projecting casing 35 is closed with a lid 38. Thus, a hermetic space is
present inside the hermetic casing 30 including the casing body 31 and the projecting
casing 35. In the present embodiment, the projecting casing 35 has a flange 37 at
the end 36b of the main body 36. The flange 37 projects outward from the main
30 body 36.

[0023]
As illustrated in Fig. 2, the cylinder 21 and the vane 23 of the compression
mechanism part 20 are housed in the casing body 31. On the other hand, a part of
the spring 26 and a part of the spring guide 27 project from the casing body 31
5 through the through hole 33a. The part of the spring 26 and the part of the spring
guide 27 projecting from the casing body 31 are disposed inside the projecting casing
35. That is, the part of the spring 26 is housed in the projecting casing 35.
[0024]
To increase the stroke volume of the hermetic compressor 100, it is necessary
10 to increase the volumes of the compression chamber 21a and the suction chamber
21b inside the cylinder 21. Thus, increasing the stroke volume of the hermetic
compressor 100 may make it difficult to leave sufficient room for the spring 26 to
extend and contract when the entire spring 26 is disposed inside the casing body 31.
However, by housing a part of the spring 26 in the projecting casing 35, it is possible
15 to leave a large installation space for the spring 26 and leave sufficient room for the
spring 26 to extend and contract even when the stroke volume of the hermetic
compressor 100 is increased.
[0025]
Next, a method for manufacturing the hermetic compressor 100 will be
20 described. Specifically, a method for manufacturing the hermetic casing 30 will be
described. In the present embodiment, the casing body 31 and the projecting casing
35 are made of a steel material. The casing body 31 and the projecting casing 35
are joined together by resistance welding. When the casing body 31 and the
projecting casing 35 are joined together by conventional resistance welding, poor
25 welding may occur at the contact area between the casing body 31 and the projecting
casing 35. As a result, when the casing body 31 and the projecting casing 35 are
joined together by the conventional resistance welding, the airtightness at the joint
between the casing body 31 and the projecting casing 35 may decrease, which may
cause leakage of refrigerant through the joint between the casing body 31 and the
30 projecting casing 35. On the other hand, joining the casing body 31 and the

11
projecting casing 35 together by resistance welding described in the present
embodiment can more reliably prevent the occurrence of poor welding at the contact
area between the casing body 31 and the projecting casing 35 than the conventional
method can and more reliably prevent reduction in the airtightness at the joint
5 between the casing body 31 and the projecting casing 35 than the conventional
method can. To facilitate understanding of this effect, hereinbelow, a method for
joining the casing body 31 and the projecting casing 35 together by the conventional
resistance welding will be described first. Then, a method for joining the casing body
31 and the projecting casing 35 together by the resistance welding according to the
10 present embodiment will be described.
[0026]
Fig. 3 is a diagram for describing a method for joining the casing body and the
projecting casing together by the conventional resistance welding. Dashed arrows in
Fig. 3 show the flow of electric current.
15 When the casing body 31 and the projecting casing 35 are joined together by
the conventional resistance welding, the casing body 31 and the projecting casing 35
are held between a first electrode 61 in contact with the end 36b of the projecting
casing 35 and a second electrode 62 in contact with the casing body 31. That is, the
first electrode 61 and the second electrode 62 apply pressure to the casing body 31
20 and the projecting casing 35. Then, in this state, an electric current is conducted
between the first electrode 61 and the second electrode 62.
[0027]
When the casing body 31 and the projecting casing 35 are joined together by
the conventional resistance welding, the distance between the first electrode 61 and
25 the second electrode 62 is long. Thus, when the electric current is conducted
between the first electrode 61 and the second electrode 62, the current decreases at
the contact area between the casing body 31 and the projecting casing 35. Thus,
when the casing body 31 and the projecting casing 35 are joined together by the
conventional resistance welding, poor welding may occur at the contact area between
30 the casing body 31 and the projecting casing 35. As a result, when the casing body

31 and the projecting casing 35 are joined together by the conventional resistance
welding, the airtightness at the joint between the casing body 31 and the projecting
casing 35 may decrease, which may cause leakage of refrigerant through the joint
between the casing body 31 and the projecting casing 35. When the voltage
5 between the first electrode 61 and the second electrode 62 is increased to increase
the current at the contact area between the casing body 31 and the projecting casing
35, the temperature of the projecting casing 35 may excessively increase, which may
deform the projecting casing 35. Thus, in the present embodiment, the casing body
31 and the projecting casing 35 are joined together by resistance welding as
10 described below.
[0028]
Fig. 4 is a flow chart for describing a method for joining the casing body and the
projecting casing together by the resistance welding according to the present
embodiment. Fig. 5 is a diagram illustrating the projecting casing of the hermetic
15 compressor according to the present embodiment with an energization auxiliary jig
attached thereto. Fig. 6 is a sectional view taken along line A-A of Fig. 5. Fig. 7 is
a diagram for describing the method for joining the casing body and the projecting
casing together by the resistance welding according to the present embodiment.
Dashed arrows in Fig. 7 show the flow of electric current.
20 [0029]
In the present embodiment, when the casing body 31 and the projecting casing
35 are joined together by the resistance welding, an energization auxiliary jig
attaching step shown as step S1 in Fig. 4 is performed. In the energization auxiliary
jig attaching step, as illustrated in Figs. 5 and 6, an energization auxiliary jig 50 is
25 attached to the projecting casing 35 to bring the energization auxiliary jig 50 into
contact with the outer periphery of the projecting casing 35. More specifically, the
energization auxiliary jig 50 is brought into contact with the outer periphery of the
main body 36 of the projecting casing 35. The energization auxiliary jig 50 is made
of a material having a higher conductivity than the material of the projecting casing
30 35. That is, the energization auxiliary jig 50 is made of a material that conducts

electricity better than the material of the projecting casing 35. In the present
embodiment, the energization auxiliary jig 50 is made of a copper alloy such as a
chrome-copper alloy.
[0030]
5 In the present embodiment, as described above, the projecting casing 35 has
the flange 37 at the end 36b. In other words, the projecting casing 35 has the flange
37 at the end 36b to be brought into contact with the first electrode 61. The
energization auxiliary jig 50 is bought into contact with not only the outer periphery of
the projecting casing 35, but also the flange 37.
10 [0031]
The energization auxiliary jig 50 according to the present embodiment includes
a first jig 51 and a second jig 52. The first jig 51 has a first recess 51a to be brought
into contact with the outer periphery of the main body 36 of the projecting casing 35.
As described above, the main body 36 has a substantially tubular shape. Thus, the
15 cross-sectional shape of the first recess 51a has a substantially arc shape
corresponding to the shape of the outer periphery of the main body 36. The second
jig 52 has a second recess 52a to be brought into contact with the outer periphery of
the main body 36 of the projecting casing 35. As with the cross-sectional shape of
the first recess 51a, the cross-sectional shape of the second recess 52a also has a
20 substantially arc shape corresponding to the shape of the outer periphery of the main
body 36. The energization auxiliary jig 50 according to the present embodiment is
configured to hold the main body 36 of the projecting casing 35 between the first jig
51 and the second jig 52 so that the energization auxiliary jig 50 is in contact with the
outer periphery of the main body 36 of the projecting casing 35. Such a
25 configuration of the energization auxiliary jig 50 facilitates bringing the energization
auxiliary jig 50 into contact with the outer periphery of the main body 36 of the
projecting casing 35. The first jig 51 and the second jig 52 holding the main body 36
of the projecting casing 35 therebetween may be fixed by any method. For example,
the first jig 51 and the second jig 52 may be fixed using a belt or a clamp.
30 [0032]

As illustrated in Fig. 4, step S2 following step S1 is a welding part placing step.
In the welding part placing step, as illustrated in Fig. 7, the projecting casing 35 and
the casing body 31 are placed between the first electrode 61 in contact with the end
36b of the projecting casing 35 and the second electrode 62 in contact with the casing
5 body 31. The energization auxiliary jig attaching step of step S1 may be performed
after the welding part placing step of step S2. As illustrated in Fig. 4, step S3
following step S1 and step S2 is a pressure applying step. In the pressure applying
step, as illustrated in Fig. 7, the first electrode 61 and the second electrode 62 hold
the casing body 31 and the projecting casing 35 therebetween and apply pressure to
10 the casing body 31 and the projecting casing 35.
[0033]
As illustrated in Fig. 4, step S4 following step S3 is an energization step. In
the energization step, as illustrated in Fig. 7, an electric current is conducted between
the first electrode 61 and the second electrode 62 applying pressure to the casing
15 body 31 and the projecting casing 35. Accordingly, resistance welding is performed
on the contact area between the casing body 31 and the projecting casing 35. That
is, in the present embodiment, the casing body 31 and the projecting casing 35 are
held between the first electrode 61 and the second electrode 62, and an electric
current is conducted between the first electrode 61 and the second electrode 62 with
20 the energization auxiliary jig 50 kept in contact with the outer periphery of the
projecting casing 35 to join the casing body 31 and the projecting casing 35 together
by resistance welding.
[0034]
When the casing body 31 and the projecting casing 35 are resistance-welded
25 together as described in the present embodiment, the electric current flowing between
the first electrode 61 and the casing body 31 mainly flows through the energization
auxiliary jig 50 made of the material having a higher conductivity than the material of
the projecting casing 35 in an area where the energization auxiliary jig 50 is present.
The electric current flowing between the first electrode 61 and the casing body 31
30 flows through the projecting casing 35 in an area where the energization auxiliary jig

50 is not present. Thus, resistance-welding the casing body 31 and the projecting
casing 35 together as described in the present embodiment can reduce, in a path for
the electric current flowing between the first electrode 61 and the casing body 31, the
length of a part of the path passing through the projecting casing 35. Thus,
5 resistance-welding the casing body 31 and the projecting casing 35 together as
described in the present embodiment can more reliably prevent decrease in the
current at the contact area between the casing body 31 and the projecting casing 35
than the conventional method can. Therefore, resistance-welding the casing body
31 and the projecting casing 35 together as described in the present embodiment can
10 more reliably prevent the occurrence of poor welding at the contact area between the
casing body 31 and the projecting casing 35 than the conventional method can and
more reliably prevent reduction in the airtightness at the joint between the casing
body 31 and the projecting casing 35 than the conventional method can.
[0035]
15 In the present embodiment, the casing body 31 and the projecting casing 35
are held between the first electrode 61 and the second electrode 62, and an electric
current is conducted between the first electrode 61 and the second electrode 62 with
the energization auxiliary jig 50 kept in contact with the outer periphery and the flange
37 of the projecting casing 35 to join the casing body 31 and the projecting casing 35
20 together by resistance welding. This makes it easy for the electric current flowing
between the first electrode 61 and the casing body 31 to flow into the energization
auxiliary jig 50 through the flange 37. As a result, it is possible to further more
reliably prevent the occurrence of poor welding at the contact area between the
casing body 31 and the projecting casing 35 and further more reliably prevent
25 reduction in the airtightness at the joint between the casing body 31 and the
projecting casing 35.
[0036]
The hermetic compressor 100 according to the present embodiment includes
the hermetic casing 30 housing the cylinder 21, the vane 23, and the spring 26. The
30 cylinder 21 has, inside thereof, the space serving as the compression chamber 21a.

The vane 23 is provided in the groove 21c formed in the cylinder 21 so as to slide.
The vane 23 partitions the space inside the cylinder 21. The spring 26 is configured
to push the vane 23 toward the space inside the cylinder 21. The hermetic casing
30 includes the casing body 31 and the projecting casing 35. The casing body 31
5 houses the cylinder 21 and the vane 23. The projecting casing 35 is welded to the
casing body 31 and projects outward from the casing body 31. The projecting
casing 35 houses a part of the spring 26.
[0037]
In the present embodiment, the casing body 31 and the projecting casing 35
10 are held between the first electrode 61 in contact with the projecting casing 35 and
the second electrode 62 in contact with the casing body 31. Then, an electric
current is conducted between the first electrode 61 and the second electrode 62 with
the energization auxiliary jig 50 made of the material having a higher conductivity than
the material of the projecting casing 35 kept in contact with the outer periphery of the
15 projecting casing 35 to join the casing body 31 and the projecting casing 35 together
by resistance welding. As described above, resistance-welding the casing body 31
and the projecting casing 35 together as described in the present embodiment can
more reliably prevent the occurrence of poor welding at the contact area between the
casing body 31 and the projecting casing 35 than the conventional method can and
20 more reliably prevent reduction in the airtightness at the joint between the casing
body 31 and the projecting casing 35 than the conventional method can.
Reference Signs List
[0038]
1: electric motor, 2: stator, 3: rotor, 10: driving shaft, 11: main shaft part, 12:
25 eccentric part, 20: compression mechanism part, 21: cylinder, 21a: compression
chamber, 21b: suction chamber, 21c: groove, 21d: suction port, 21e: discharge port,
22: rolling piston, 23: vane, 23a: end, 23b: end, 24: first bearing part, 25: second
bearing part, 26: spring, 26a: end, 26b: end, 27: spring guide, 30: hermetic casing,
31: casing body, 32: upper casing, 33: middle casing, 33a; through hole, 34: lower
30 casing, 35: projecting casing, 36: main body, 36a: end, 36b: end, 37 flange, 38: lid,

39: discharge pipe, 40: suction pipe, 41: accumulator, 50: energization auxiliary jig,
51: first jig, 51a: first recess, 52: second jig, 52a: second recess, 61: first electrode,
62: second electrode, 100: hermetic compressor

We Claim:
[Claim 1]
A method for manufacturing a hermetic compressor, the hermetic compressor
5 including a hermetic casing housing a cylinder having, inside thereof, a space serving
as a compression chamber, a vane provided in a groove formed in the cylinder so as
to slide, the vane partitioning the space, and a spring configured to push the vane
toward the space,
the hermetic casing including
10 a casing body housing the cylinder and the vane, and
a projecting casing welded to the casing body, projecting outward from
the casing body, and housing a part of the spring,
the method comprising:
holding the casing body and the projecting casing between a first
15 electrode in contact with the projecting casing and a second electrode in contact with
the casing body; and
conducting an electric current between the first electrode and the second
electrode with an energization auxiliary jig made of a material having a higher
conductivity than a material of the projecting casing kept in contact with an outer
20 periphery of the projecting casing to join the casing body and the projecting casing
together by resistance welding.
[Claim 2]
The method for manufacturing the hermetic compressor of claim 1, wherein
the energization auxiliary jig includes
25 a first jig having a first recess to be brought into contact with the outer
periphery of the projecting casing, and
a second jig having a second recess to be brought into contact with the
outer periphery of the projecting casing, and
the projecting casing is held between the first jig and the second jig to bring the
30 energization auxiliary jig into contact with the outer periphery of the projecting casing.

19
[Claim 3]
The method for manufacturing the hermetic compressor of claim 1 or 2,
wherein
the projecting casing has a flange at an end to be brought into contact with the
5 first electrode, and
an electric current is conducted between the first electrode and the second
electrode with the energization auxiliary jig kept in contact with the outer periphery
and the flange of the projecting casing to join the hermetic casing and the projecting
casing together by resistance welding.
10 [Claim 4]
The method for manufacturing the hermetic compressor of any one of claims 1
to 3, wherein the energization auxiliary jig is made of a copper alloy.