JP2014240626A - Hermetic electric compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hermetic electric compressor capable of reducing heating loss and channel loss of intake gas in an intake pipe, and improving sealability of an inlet pipe press-fitted portion.SOLUTION: A hermetic electric compressor comprises: a hermetic vessel 1; a compression mechanism portion 2 and an electric motor portion provided in this hermetic vessel 1; and an intake pipe 16 passing through the hermetic vessel 1 for introducing refrigerant gas into an intake port 19a of the compression mechanism portion 2. The refrigerant gas introduced from this intake pipe 16 is compressed by the compression mechanism portion 2 and discharged into the hermetic vessel 1, so that an interior of the hermetic vessel 1 around the intake pipe 16 is filled with the discharged gas discharged from the compression mechanism portion 2. The intake pipe 16 is configured to have a double-pie structure of an inner pipe 16a and an outer pipe 16b pressure-welded to an outside of the inner pipe 16a, and the inner pipe 16a is formed out of a material higher in strength than the outer pipe 16b and low in heat conductivity.

Description

  The present invention relates to a hermetic electric compressor in which a compression mechanism unit and an electric motor unit are housed in a hermetic container, and is particularly suitable as a refrigerant compressor such as an air conditioner or a water heater.

  As a conventional hermetic electric compressor, for example, a scroll-type hermetic electric compressor described in Japanese Patent Application Laid-Open No. 2012-241629 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2012-154212 (Patent Document 2) is used. Are known.

  In what is shown in Patent Document 1, as shown in FIG. 1, the hermetic electric compressor has a configuration in which a compression mechanism portion and an electric motor portion that drives the compression mechanism portion are housed in a hermetic container. Further, the suction pipe is connected to a suction port provided at a peripheral edge of the fixed scroll of the compression mechanism unit, and the refrigerant gas from the refrigeration cycle is guided to the suction port via the suction pipe. The refrigerant gas guided to the suction port is compressed by the compression mechanism, discharged from the discharge port provided at the center of the base plate of the fixed scroll into the sealed container, and supplied from the discharge pipe to the refrigeration cycle again. It has become.

  In the one shown in Patent Document 2, as shown in FIG. 1, a copper suction pipe is inserted into a suction port provided at the peripheral edge of the fixed scroll, and a steel seal part with high strength is provided inside the suction pipe. Is pressed to roll the copper pipe (suction pipe), thereby bringing the suction pipe into close contact with the suction port and improving the sealing performance of the press-fitting portion.

JP 2012-241629 A JP 2012-154212 A

  In the above-described conventional hermetic electric compressor, since the sealed container is filled with the discharge gas and the periphery of the suction pipe is also filled with the discharge gas, the working gas (gas refrigerant) in the suction pipe is discharged. It is configured to be heated by gas.

  That is, in the hermetic electric compressor shown in Patent Document 1, the suction pipe is composed of a copper pipe and a steel pipe joined to the tip of the copper pipe by brazing in the furnace. It is configured to press fit into the suction port of the fixed scroll. For this reason, the production of the suction pipe is expensive because it is brazed in the furnace. The suction pipe is made of a material having high thermal conductivity such as a copper pipe or a steel pipe, and the low-temperature and low-pressure suction gas (refrigerant gas) flowing through the suction pipe is generated by the high-temperature and high-pressure discharge gas in the sealed container. There was a problem that the volume of the suction gas was increased by this heating, and the volumetric efficiency was lowered.

  In particular, when R32 or R744 is used as the refrigerant, the temperature difference between the suction gas flowing in the suction pipe and the compressed discharge gas existing outside the suction pipe is increased, and the discharge of the suction gas is increased. The amount of heating by gas increases. For this reason, since the volume increase amount of the said suction gas also becomes large, the subject that the volumetric efficiency fall in a compressor becomes especially remarkable occurs.

  Furthermore, the suction pipe is press-fitted into the suction port provided at the peripheral edge of the fixed scroll of the compression mechanism, but the fastening of the fixed scroll and the suction pipe is due to the press-fitting of steel materials. If the press-fitting part is not manufactured with high dimensional accuracy, it cannot be brought into close contact with each other, and it is difficult to make close contact due to the inclination or the like during press-fitting.

  In the above-mentioned Patent Document 2, a steel seal part is press-fitted into a suction pipe formed of a copper pipe, and the suction pipe is brought into close contact with the suction port of the fixed scroll, thereby improving the sealing performance of the press-fitting part. To reduce leakage. However, in this structure, since the connection part of the suction pipe to the fixed scroll suction port is press-fitted by the seal part, the inner diameter of the press-fitting part of the suction pipe is reduced by the seal part, and the step further Since it also becomes an attachment structure, the wall surface flow path loss of a suction pipe becomes large and there exists a subject which reduces compressor efficiency.

  An object of the present invention is to obtain a hermetic electric compressor that can reduce the heating loss and flow path loss of suction gas in the suction pipe, and further improve the sealing performance of the suction pipe press-fitting portion.

  In order to achieve the above object, the present invention provides a sealed container, a compression mechanism provided in the sealed container, an electric motor provided in the sealed container for driving the compression mechanism, and the sealed A suction pipe for guiding the refrigerant gas to the suction port of the compression mechanism portion through the container, and the refrigerant gas guided from the suction pipe is compressed by the compression mechanism portion and discharged into the sealed container, The closed container around the suction pipe is a hermetic electric compressor configured to be filled with the discharge gas discharged from the compression mechanism unit, and the suction pipe is crimped to the inner pipe and the outer side of the inner pipe. The inner pipe is formed of a material having higher strength and lower thermal conductivity than the outer pipe.

  According to the present invention, it is possible to reduce the heating loss and flow path loss of the suction gas in the suction pipe, and to obtain an effect of obtaining a hermetic electric compressor capable of improving the sealing performance of the suction pipe press-fitting portion. .

It is a longitudinal cross-sectional view which shows Example 1 of the hermetic type electric compressor of this invention. It is a principal part expanded sectional view which shows the structure of the suction pipe vicinity shown in FIG. It is an expanded sectional view which expands and shows the III section shown in FIG. It is an expanded sectional view which expands and shows the IV section shown in FIG. FIG. 10 is a diagram illustrating a modification of the first embodiment and corresponds to FIG. 3. FIG. 10 is a diagram illustrating a modification of the first embodiment and corresponds to FIG. 4. It is a figure which shows Example 2 of the hermetic type electric compressor of this invention, and is a figure equivalent to FIG.

  Hereinafter, specific examples of the hermetic electric compressor of the present invention will be described with reference to the drawings. In each figure, the part which attached | subjected the same code | symbol has shown the part which is the same or it corresponds.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view showing a first embodiment of a hermetic electric compressor according to the present invention, FIG. 2 is an enlarged sectional view of a main part showing a configuration in the vicinity of a suction pipe shown in FIG. 1, and FIG. FIG. 4 is an enlarged cross-sectional view showing the IV portion shown in FIG. 2 in an enlarged manner.

  First, the overall configuration of the hermetic electric compressor according to the first embodiment will be described with reference to FIG. The hermetic electric compressor 50 in the present embodiment is composed of a hermetic scroll compressor, such as an air conditioner, a refrigerator, a freezer, a refrigeration air conditioner such as a refrigeration / freezer showcase, or a heat pump hot water supply device. It is used as a component device of a refrigeration cycle apparatus.

  In FIG. 1, 1 is a sealed container, 2 is a compression mechanism part, 3 is a fixed scroll, 3a is a fixed scroll wrap configured in a spiral shape, 4 is a orbiting scroll, 4a is a orbiting scroll wrap configured in a spiral shape, 5 Is a frame having a main bearing 7 for rotationally supporting the crankshaft 5, and the frame 6 is fixed to the sealed container 1 of the hermetic electric compressor 50 by welding or the like. The fixed scroll 3 is fixed by a bolt 8 or the like. Reference numeral 9 denotes an Oldham ring for preventing the rotation of the orbiting scroll 4 and causing the orbiting movement to occur. Reference numeral 10 denotes an electric motor unit for driving the compression mechanism unit 2. The electric motor unit 10 is fixed to the sealed container 1. The stator 11 and the rotor 12 configured to rotate integrally with the crankshaft 5 are included. A balance weight 12 a for maintaining a rotational balance with the compression mechanism 2 is fixed to the rotor 12.

  The sealed container 1 is sealed by a cylindrical tube portion 1a, and an upper lid portion 1b and a lower lid portion 1c that are welded to the top and bottom of the tube portion 1a, and the inside is a sealed space. The unit 2 and the motor unit 10 are accommodated. In addition, an oil sump 13 is formed at the bottom of the sealed container 1 to store refrigeration oil (lubricating oil).

In the compression mechanism portion 2, the wrap 3 a of the fixed scroll 3 and the wrap 4 a of the orbiting scroll 4 are engaged with each other to form a compression chamber 14.
The upper lid portion 1b of the sealed container 1 is provided with a suction inner pipe 15 and a suction pipe 16 penetrating through the upper lid portion 1b, and the suction pipe 16 is fixed to the upper lid portion 1b of the sealed container 1. A suction outer pipe 17 is provided. The suction inner pipe 15 and the suction outer pipe 17 are made of copper pipes. In the present embodiment, the suction pipe 16 has a double-pipe structure with an inner pipe made of stainless steel and an outer pipe made of copper.

The copper outer suction pipe 17 is configured in advance as a unitary structure by means of a truncated cone-shaped member 17a made of steel and brazing in the furnace, and the truncated cone-shaped member 17a serves as an upper lid portion 1b of the sealed container 1. By welding so as to penetrate, the space between the sealed container 1 and the suction outer pipe 17 is sealed.
A discharge pipe 18 is provided in the cylindrical portion 1a of the sealed container 1 so as to penetrate the cylindrical portion 1a.

  The suction inner pipe 15 is connected to and communicates with an external refrigeration cycle, and is configured to guide refrigerant gas from the refrigeration cycle into the hermetic electric compressor 50. Thus, when the compression mechanism unit 2 is driven by the electric motor unit 10, refrigerant gas is provided in the compression mechanism unit 2 from the external refrigeration cycle via the suction inner pipe 15 and the suction pipe 16. And is compressed in the compression chamber 14 of the compression mechanism 2 and discharged from the discharge port 3c formed in the center portion of the base plate 3b of the fixed scroll 3 to the upper space (discharge chamber) 20 in the sealed container 1. It is comprised so that. The high-temperature compressed gas (refrigerant gas) discharged into the upper space 20 passes through a passage (not shown) formed between the fixed scroll 3, the outer periphery of the frame 6, and the sealed container 1. Then, the refrigerant gas flows into the space on the electric motor unit side in the hermetic container 1 and then the compressed refrigerant gas is sent to the external refrigeration cycle via the discharge pipe 18.

  The suction pipe 16 is press-fitted into a circular suction port 19 a of the suction chamber 19 and fastened. In the present embodiment, the suction pipe 16 has a double-pipe structure manufactured by pressure-bonding two different metals as shown in FIG. That is, the suction pipe 16 is constituted by an inner pipe 16a and an outer pipe 16b that is crimped to the outer side of the inner pipe 16a. The inner pipe 16a is made of a material having a low thermal conductivity, such as stainless steel having a thermal conductivity of 30 W / (m · K) or less (in the case of SUS304, the thermal conductivity is 16 W / (m · K)). The outer pipe 16b is made of a copper material.

  In addition, the suction pipe 16 having such a double-pipe structure can be easily manufactured by a drawn pipe (cold pressure drawn pipe) using a three-roll cold rolling mill. In the present embodiment, the inner pipe 16a and the outer pipe 16b have substantially the same thickness. However, the heat insulation, strength, press-fit workability, the suction inner pipe 15 and the suction outer pipe are the same. These thicknesses may be selected in consideration of, for example, brazing with 17.

  When the suction pipe 16 having the double-pipe structure manufactured as described above is press-fitted into the circular suction port 19a of the suction chamber 19, the suction pipe 19 is composed of the inner surface of the suction port 19a and high-strength stainless steel. Between the inner pipe 16a, the outer pipe 16b made of copper having a low Young's modulus is rolled together with the press-fitting and is brought into close contact with the suction port 19a. Therefore, the sealing performance of the connection portion between the suction pipe 16 and the suction chamber 19 can be improved.

  Further, according to the present embodiment, since the suction pipe 16 has the double pipe structure as described above, an assembly error occurs during the assembly operation in which the suction pipe 16 is press-fitted into the suction port 19a of the fixed scroll 3 and connected. For example, even when the suction pipe 16 is connected with a slight inclination, the outer pipe 16b made of copper can be rolled and brought into close contact with the inclination. Therefore, even when the suction pipe 16 is inclined and connected due to an assembly error or the like, the amount of leakage from the connecting portion can be reduced, so that the assemblability can be improved.

  Furthermore, according to the present embodiment, the inner pipe 16a made of stainless steel having high heat insulation performance allows the inside of the suction pipe 16 from the high-temperature and high-pressure compressed gas (refrigerant gas) in the upper space on the outer periphery side of the suction pipe 16. Heat transfer to the low-temperature and low-pressure suction gas sucked through the air can be suppressed. Therefore, since the temperature rise of the suction gas sucked from the suction pipe 16 can be suppressed, the suction heating loss can be reduced and the volume efficiency can be improved.

  In particular, when R32 or R744 is used as the refrigerant, the temperature difference between the discharge gas and the suction gas becomes large, so that the heat conductivity is high as in the suction pipe described in Patent Document 1 and Patent Document 2 described above. In what is comprised with material, the heating amount of suction gas becomes large and a volume change will also become large. On the other hand, since the suction pipe 16 according to the present embodiment has a large heat insulating effect, the effect of improving the volumetric efficiency when R32 or R744 is used as the refrigerant is particularly remarkable.

  Further, in this embodiment, unlike the suction pipe described in Patent Document 2 described above, since the suction pipe is not press-fitted into the suction port using a sealing part, the inner diameter of the press-fit portion of the suction pipe Is not required to have a stepped structure reduced by the sealing part. Therefore, since the inner surface of the suction pipe 16 can be formed straight over the entire length, the flow path loss of the inner wall surface of the suction pipe can be minimized, thereby improving the performance.

Next, the attachment structure of the suction pipe 16 in a present Example is demonstrated with reference to FIG.2 and FIG.3.
The suction pipe 16 is connected to the inner surface side of the suction pipe 16 by brazing or the like for connection to the refrigeration cycle (see the brazing part 21). The suction pipe 16 is connected to the suction surface of the suction pipe 16 on the outer surface side. Similarly, the pipe 16 is connected to the suction outer pipe 17 for fixing the pipe 16 to the upper lid portion 1b of the sealed container 1 by brazing or the like (see the brazing portion 23).

  Here, when a phosphor copper brazing is used as the brazing, the inner diameter side of the suction pipe 16 is stainless steel (non-copper material), and therefore the phosphor copper brazing is difficult to join with the stainless steel. Therefore, in this embodiment, the brazing portion 21 between the suction inner pipe 15 and the suction pipe 16 is chamfered on the inner diameter side of the upper end portion (end portion) of the suction pipe 16 as shown in an enlarged view in FIG. 22 is given. By configuring in this way, the stainless steel inner pipe 16a does not protrude upward from the upper end (end) of the copper outer pipe 16b, so that the copper outer pipe 16b portion becomes the copper suction inner pipe 15. Strong phosphorous copper brazing. As a result, a structure with good phosphor copper brazing can be obtained, and the connection strength and sealing performance at the brazing portion 21 can be improved.

  The outer surface side of the suction pipe 16 is also brazed with phosphorous copper to the suction outer pipe 17 as shown by a brazing portion 23. Since this brazing portion 23 is a joint between the copper outer pipe 16b and the copper suction outer pipe 17, it is possible to easily perform phosphorous copper brazing with a strong and good sealing property.

  Further, in this embodiment, as shown in FIG. 1, when the operation of the hermetic electric compressor 50 is stopped in the suction chamber 19, the refrigerant gas flows backward from the compression chamber 14 side to the suction pipe 16 side. To prevent this, a check valve 24 is installed. When the operation of the compressor 50 is started, the check valve 24 is pushed downward by the flow of the sucked gas, but when the operation is stopped, the check valve 24 is moved upward by a spring 25. And is brought into contact with the lower end surface of the suction pipe 16. Therefore, the compressed gas in the compression chamber 14 can be prevented from flowing backward to the low pressure suction side.

  Thus, in the case of the hermetic electric compressor 50 including the check valve 24, the lower end surface of the suction pipe 16 is in contact with the check valve 24 to prevent the backflow of the compressed refrigerant gas. Flatness is required. Therefore, as shown in FIGS. 2 and 4, the suction pipe 16 is chamfered 26 on the outer diameter side of its lower end surface (the end surface facing the check valve), and the lower end surface of the suction pipe 16 has an inner diameter. The side material (inner pipe 16a) is formed to be stainless steel. With this configuration, the lower end surface of the suction pipe 16 with which the check valve 24 abuts is made of high-strength stainless steel, so that the flatness of the lower end surface of the suction pipe can be maintained for a long period of time, and the compressed gas The effect of preventing the backflow to the suction side can be improved.

A modification of the first embodiment will be described below with reference to FIGS.
FIG. 5 is a view showing a modification of the first embodiment and corresponds to FIG. In the example illustrated in FIG. 3, the chamfer 22 is provided on the inner diameter side of the upper end of the suction pipe 16. However, in the modification illustrated in FIG. 5, the upper end (end) of the inner pipe 16 a of the suction pipe 16. Is cut shorter than the upper end (end) of the outer pipe 16b.

  By configuring in this way, the surface area on the upper end side of the copper outer pipe 16b can be increased, so that the connection with the copper suction inner pipe 15 can be brazed more easily and reliably by phosphor copper brazing. Thus, the phosphor copper brazeability can be further improved. Therefore, the effect of further improving the connection strength and the sealing performance at the brazed portion 21 between the suction inner pipe 15 and the suction pipe 16 can be obtained.

  FIG. 6 is also a diagram showing a modification of the first embodiment, and corresponds to FIG. In FIG. 4 described above, chamfering 26 is performed on the outer diameter side of the lower end portion of the suction pipe 16 so that the lower end surface of the suction pipe 16 is made of stainless steel as the inner diameter side material. Part of 26 extends to part of the inner pipe 16a. On the other hand, in the modification shown in FIG. 6, the chamfer 26 is provided only on the outer diameter side of the lower end portion of the outer pipe 16 b of the suction pipe 16.

  Even in this configuration, since the outer pipe 16b is made of copper having a low Young's modulus, there is a portion that protrudes toward the check valve 24 from the inner pipe 16a on the lower end surface of the outer pipe 16b. Even if the collision with the check valve 24 is repeated, the lower end surface of the copper outer pipe 16b does not protrude to the check valve 24 side than the inner pipe 16a made of stainless steel. Therefore, the lower end surface of the suction pipe 16 can be made of stainless steel as an inner diameter side material, and the area in contact with the check valve 24 can be made larger including the lower end surface of the outer pipe 16b. Therefore, the effect of more reliably suppressing the backflow of compressed gas to the suction pipe 16 side can be obtained.

  A sealed electric compressor according to a second embodiment of the present invention will be described with reference to FIG. FIG. 7 corresponds to FIG. 2 of the first embodiment. However, in FIG. 7, the configuration in the vicinity of the connection portion between the suction pipe 16 and the fixed scroll 2 shown in FIG. 2 is not shown, and the connection portion between the suction inner pipe 15 and the suction pipe 16, and the suction pipe 16 and the suction pipe. The connection part of the outer pipe 17 is shown enlarged.

  In the second embodiment, the connection portion 15a of the suction inner pipe 15 connected to the suction pipe 16 is expanded larger than the outer diameter of the suction pipe 16, and the suction pipe 16 is inserted inside the connection portion 15a. In this connection, the entire circumference of the outer peripheral surface of the suction pipe 16 is connected by phosphorous copper brazing. In this way, by expanding the suction inner pipe 15, it is possible to braze the copper outer pipe 16 b of the suction pipe 16, so that phosphorous copper brazing can be easily performed.

  Moreover, in the present Example 2, the connection part 15a of the said suction inner pipe 15 is expanded so that it may become the same diameter as the diameter of the suction outer pipe 17. FIG. Therefore, as shown in FIG. 7, it is possible to braze phosphor copper at a time with a single brazing portion 27, including the suction inner pipe 15, the suction pipe 16, and the suction outer pipe 17, so There is also an effect that the attaching work can be further facilitated.

  Furthermore, according to the second embodiment, the chamfering of the upper end inner diameter portion of the suction pipe 16 described in the first embodiment can be eliminated, so that the structure can be further simplified and the cost can be reduced. it can. The other points are basically the same as those of the first embodiment.

  According to each embodiment of the present invention described above, the heat loss and flow path loss of the suction gas in the suction pipe 16 can be reduced, and further, the seal at the press-fitting portion of the suction pipe 16 to the fixed scroll suction port 19a. This has the effect of improving the performance.

  Further, according to each embodiment of the present invention, the suction pipe has a double pipe structure, but the double pipe structure of the suction pipe can be easily manufactured by a cold pressure drawing pipe, etc. Compared to the conventional suction pipes described in Documents 1 and 2, the structure is simplified, and seal parts are not required, and the number of parts can be reduced, so that assembly is facilitated. Therefore, according to each embodiment of the present invention, there is an effect that the cost can be reduced.

In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, in the above-described embodiment, the inner pipe of the suction pipe is made of stainless steel, but may be a member having a low thermal conductivity and high strength, and may be made of, for example, titanium. In the above-described embodiment, the case where the hermetic type electric compressor is applied to the hermetic scroll compressor has been described. However, the present invention is not limited to the scroll type compressor, and the same applies to the rotary type and the reciprocating type. Applicable.
Further, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

DESCRIPTION OF SYMBOLS 1 ... Airtight container, 1a ... Tube part, 1b ... Upper cover part, 1c ... Lower cover part,
2 ... compression mechanism,
3 ... fixed scroll, 3a ... fixed scroll wrap, 3b ... base plate, 3c ... discharge port,
4 ... turning scroll, 4a ... turning scroll wrap,
5 ... Crankshaft, 6 ... Frame, 7 ... Main bearing, 8 ... Bolt, 9 ... Oldham ring,
DESCRIPTION OF SYMBOLS 10 ... Electric motor part, 11 ... Stator, 12 ... Rotor, 12a ... Balance weight,
13 ... Oil sump, 14 ... Compression chamber,
15 ... Suction pipe,
16 ... Suction pipe, 16a ... Inner pipe, 16b ... Outer pipe,
17 ... Outer pipe, 17a ... Conical member,
18 ... discharge pipe,
19 ... Suction chamber, 19a ... Suction port, 20 ... Upper space (discharge chamber),
21, 23, 27 ... brazing part,
22, 26 ... chamfering,
24 ... Check valve, 25 ... Spring,
50: Hermetic electric compressor.

Claims (9)

An airtight container, a compression mechanism portion provided in the airtight container, an electric motor portion provided in the airtight container for driving the compression mechanism portion, and a suction port of the compression mechanism portion penetrating the airtight container A suction pipe for guiding the refrigerant gas to the refrigerant pipe, and the refrigerant gas guided from the suction pipe is compressed by the compression mechanism and discharged into the sealed container, and the inside of the sealed container around the suction pipe is the A hermetic electric compressor configured to be filled with a discharge gas discharged from a compression mechanism,
The suction pipe is configured in a double pipe structure with an inner pipe and an outer pipe crimped to the outside of the inner pipe,
The hermetic electric compressor is characterized in that the inner pipe is made of a material having higher strength and lower thermal conductivity than the outer pipe.   2. The hermetic electric compressor according to claim 1, wherein the suction pipe has a double pipe structure in which the inner pipe is made of stainless steel and the outer pipe is made of copper, and these two different metals are crimped together. A hermetic electric compressor characterized by having   3. The hermetic electric compressor according to claim 2, wherein a copper suction pipe connected to a refrigeration cycle is connected to the suction pipe, and the suction pipe is fixed to the sealed container. Copper suction outer pipe, the suction pipe, the suction inner pipe and the suction outer pipe are joined by brazing, and the brazed portion between the suction inner pipe and the suction pipe is inside the suction pipe. A hermetic electric compressor characterized in that the outer pipe made of copper and the suction inner pipe made of copper are brazed so that the pipe does not protrude beyond the end of the outer pipe.   4. The hermetic electric compressor according to claim 3, wherein the brazing portion between the suction inner pipe and the suction pipe is chamfered on the inner diameter side of the end of the suction pipe so that the inner pipe becomes the outer A hermetic electric compressor characterized by being configured not to protrude from an end of a pipe.   4. The hermetic electric compressor according to claim 3, wherein a brazing portion between the suction inner pipe and the suction pipe is configured such that an end of the inner pipe of the suction pipe is shorter than an end of the outer pipe. Thus, the hermetic electric compressor is configured such that the inner pipe does not protrude beyond the end of the outer pipe.   3. The hermetic electric compressor according to claim 2, wherein a copper suction pipe connected to a refrigeration cycle is connected to the suction pipe, and the suction pipe is fixed to the sealed container. The suction pipe, the suction inner pipe, and the suction outer pipe are joined by brazing, and the brazed portion between the suction inner pipe and the suction pipe is connected to the suction inner pipe. The connection portion of the suction pipe is expanded larger than the outer diameter of the suction pipe, the suction pipe is inserted inside the connection portion, and the copper outer pipe outer peripheral surface of the suction pipe and the copper suction inner portion A hermetic electric compressor characterized in that a pipe is brazed.   The hermetic electric compressor according to any one of claims 1 to 6, wherein the compression mechanism portion of the suction pipe is configured to prevent backflow of refrigerant gas from the compression chamber of the compression mechanism portion to the suction pipe side. A hermetic electric compressor comprising a check valve disposed so as to face a side end face, and chamfering the end face outer diameter side of the suction pipe facing the check valve.   7. The hermetic electric compressor according to claim 1, wherein an inner surface of the suction pipe is formed straight over the entire length thereof.   7. The hermetic electric compressor according to claim 1, wherein the refrigerant gas is R32 or R744.

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