JP2005054652A - Hermetic compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability by using a refrigerant such as CO2 having a high operating pressure, or increasing the strength of a joint part between a sealed container and a gas pipe, preventing gas leakage or breakage at the joint part.
SOLUTION: A gas pipe is fitted into a pipe insertion hole provided in a partition wall of a hermetic container by brazing and joined, and a working gas flows into or out of the hermetic container, and the gas pipe is a circular pipe. In addition, a deformed part having a larger outer diameter than the circular pipe part is provided, and the different diameter part is disposed inside the joint part with the pipe insertion hole or the joint part, so that the different diameter part acts as a stopper, The gas pipe can be firmly joined to the partition wall of the sealed container.
[Selection] Figure 2

Description

  The present invention relates to a hermetic compressor used for refrigeration equipment, air conditioning equipment, and the like, and particularly relates to a container structure suitable for a hermetic compressor that compresses carbon dioxide gas, which is a high-pressure refrigerant gas, to a high pressure. .

  As hermetic electric compressors for refrigerating and air-conditioning, there are reciprocating, rolling piston, and scroll types of compression mechanisms, and both methods are used in the field of refrigerating and air-conditioning for home use and business use. Both types of compressors are configured by accommodating a compression mechanism, a driving shaft, an electric motor, and the like in an airtight container (see, for example, Patent Document 1).

  Here, the conventional technology will be described by taking as an example a scroll compressor that is an HCFC refrigerant R22, an HFC R410A refrigerant, or the like and is used at an operating pressure of 5 MPa or less.

  FIG. 6 shows a longitudinal sectional view of a conventional scroll compressor.

  The sealed container 1 includes a cylindrical shell shell 21, a deep dish-shaped upper end plate 22 and a bottom end plate 23 which are circumferentially welded to the upper end side and the lower end side thereof. Further, a suction outer tube 24 is connected to a tube insertion hole 21a provided in the body shell 21, and a discharge tube 16 is connected to the tube insertion hole 22a provided in the upper end plate 22 by brazing. The suction pipe 11 is inserted into the suction outer pipe 24 and is brazed and fixed circumferentially. The introduction terminal 25 is joined to the upper end plate 22 by resistance welding or the like.

  Inside the hermetic container 1 are a compression mechanism portion 2 composed of a fixed scroll 2a and a movable scroll 3, a shaft 5 for rotating the movable scroll 3 with respect to the fixed scroll 2a via an Oldham coupling 4, and a fixed scroll. A bearing member 6 is provided that fixes the shaft 2a and rotatably supports the shaft 5.

  A rotor 7 a of an electric motor 7 is attached to the shaft 5, and is disposed below the bearing member 6 together with a stator 7 b that is shrink-fitted and fixed to the body shell 21.

  An oil sump 10 for storing the lubricating oil 9 is provided at the lower bottom of the sealed container 1, and the oil 9 in the oil sump 10 is removed from the lower end of the through hole 13 of the shaft 5 by the oil pump 17 as the shaft 5 rotates. Sucking up and supplying to the journal bearing 6a, the eccentric bearing 3a, and each sliding surface.

  Next, the refrigerant gas compression cycle in the conventional scroll compressor having the above-described configuration will be described. The low-pressure refrigerant gas that has circulated through the heat exchanger (not shown) of the air conditioner is sucked into the compression mechanism 2 through the suction pipe 11.

  The sucked refrigerant gas enters a crescent-shaped compression space (not shown) formed between the fixed scroll 2 a and the movable scroll 3, and the crescent-shaped compression space is centered from the outside by the turning motion of the movable scroll 3. The refrigerant gas is compressed to become a high-pressure gas and is discharged from the discharge hole 12 by being gradually reduced toward.

The high-pressure gas discharged from the discharge hole 12 is once discharged into the discharge space 1a above the fixed scroll 2a in the hermetic container 1 and flows through the gas passage 14 to the lower space 1b in which the electric motor 7 is accommodated. The gas flows through an upper space 1c through a gas passage 15 provided separately from the passage 14, and is discharged from the discharge pipe 16 to an external air conditioning system such as a heat exchanger (not shown). The high-pressure gas circulates in a heat exchanger or the like of the air conditioner in the air-conditioning system to become a low-pressure gas and constitutes a known compression cycle that returns to the compressor from the suction pipe 11 again.

However, in order to cope with global environmental problems, HFC refrigerants that are more efficient and have a lower global warming potential than conventional CFCs such as R12 and HCFC refrigerants such as R22, which are more suitable for suppressing global warming ( For example, an HFC refrigerant having R410A or R32 or the like as a main component, or a natural refrigerant having a smaller global warming potential, for example, carbon dioxide (hereinafter referred to as CO2) or the like. Use is in progress. In order to cope with these refrigerants, a compressor having a conventional structure has the following problems.
JP 2002-161856 A

  Many of these refrigerants have higher operating pressure than the conventional refrigerant R22 and the like in order to increase the system efficiency of the equipment due to the characteristics of the refrigerant. Therefore, the compression mechanism section and the sealed container are strengthened by increasing their plate thickness. It was necessary to do.

  For example, when the discharge pressure acts on the inner wall of the sealed container 1 (the space in which the electric motor 7 is accommodated) as in the configuration of the compressor shown in FIG. The pressure use range is less than about 5 MPa, and the shell shell 21 has an inner diameter of about 110 mm). However, in the case of CO2 refrigerant, the discharge pressure use range is about 15 Mpa, and the R22 refrigerant When the material having the same strength as the material of the closed container 1 corresponding to the above is used, the plate thickness of the shell is required to be about 8 mm, which is twice or more.

  Further, not only the thickness of the sealed container 1 but also the joining of the suction pipe 24 and the discharge pipe 16 to the sealed container 1 is required to be stronger. The case where the plate | board thickness of the airtight container 1 is made thick with the conventional structure so that it may respond to CO2 gas is demonstrated using FIG.

  FIG. 7 is a cross-sectional view of a portion where the discharge pipe 16 is joined to the upper end plate 22 having a plate thickness t1. As shown in FIG. 7, the discharge pipe 16 is a circular pipe having a substantially uniform pipe diameter (d0 in the figure) and is inserted into a pipe insertion hole 22a formed at a predetermined position of the upper end plate 22, Join with brazing.

  The diameter d1 of the tube insertion hole 22a here is substantially uniform from the outer surface side to the inner surface side of the upper end plate 22, and is drilled so as to be slightly larger than the diameter d0 of the discharge tube 16. .

  In brazing, the brazing material enters and solidifies into the gap between the diameter d0 of the suction outer pipe 24 and the diameter d1 of the pipe insertion hole 21a, and the both are joined. This is performed at the joint 31 formed of the brazing material that has been solidified by protruding from the gap.

  However, in the brazing joining in the configuration shown in FIG. 7, a joining strength sufficient to withstand the high operating pressure of the CO 2 refrigerant cannot be obtained.

  Therefore, in order to obtain a strong joint strength, there is a method of fixing by welding. However, when the discharge pipe 16 is circumferentially welded to the upper end plate 22, a greater amount of heat is locally applied than in the case of brazing. When the temperature is locally raised and cooled, the upper end plate 22 is deformed by the heat, causing problems such as hindering the joining of the introduction terminal 25.

  The present invention solves the above-described conventional problems, and even when a refrigerant gas (including fluid) having a high operating pressure such as CO 2 is used, an intake pipe and a discharge pipe can be easily attached to the upper end plate 22 and the like. It is an object of the present invention to provide a hermetic compressor with high productivity and reliability.

  In order to achieve the above object, the present invention provides a hermetic container, a compression mechanism that is provided in the hermetic container and sucks and compresses the working gas, a drive shaft that drives the compression mechanism, and the An electric motor that rotates the drive shaft, and a gas pipe that is fitted and joined by brazing into a pipe insertion hole provided in a partition wall of the sealed container, and allows the working gas to flow into or out of the sealed container. It is a circular pipe, and a deformed part having an outer diameter partially larger than that of the circular pipe part is provided, and the different diameter part is arranged on the inner side of the joint part or the joint part with the pipe insertion hole.

  According to the present invention, even when a refrigerant having a high operating pressure such as CO 2 is used, the gas pipe can be firmly joined to the sealed container, so that a highly reliable hermetic compressor can be realized.

  Embodiments of the present invention will be described below with reference to the drawings. In the configuration of the scroll compressor used in one embodiment of the present invention, the same reference numerals are used for the same functional parts as those in the prior art example described in FIG. 6, and the description of the same configuration and operation is omitted. .

  Further, the scroll compressor according to the embodiment of the present invention will be described by taking an example in which carbon dioxide is used as a refrigerant (hereinafter referred to as CO2). It is also applicable to the case where the pressure exceeds 5 MPa, the case where HFC refrigerant R410A, R32, or hydrocarbon (HC)) or the like, or a lower refrigerant such as conventional HCFC22 is used, Similar effects can be obtained.

(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIGS.

  1 is a longitudinal sectional view of a scroll compressor according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the main part used for the description in the first embodiment of the present invention.

  In FIG. 1, the sealed container 1 includes a cylindrical shell 21, and an upper end plate 22 and a bottom end plate 23 that are circumferentially welded to the upper end side and the lower end side thereof, as in the conventional configuration of FIG. 6. . A refrigerant gas suction pipe 11 is joined to the body shell 21, and a discharge pipe 16 is joined to the upper end plate 22. Since CO2 is used as the working gas, the plate thickness of the sealed container 1 is thicker than before, and the shapes of the upper end plate 22 and the bottom end plate 23 are deeper than the conventional one so as to be advantageous in terms of strength. Yes.

  Although there is a change in the suction volume of the compression unit in accordance with the characteristics of the refrigerant, the compression mechanism 2 operates in the same manner as the conventional example, and the refrigerant gas is sucked from the suction pipe 11 and discharged from the discharge pipe 16. In the airtight container 1, the same flow operation as in the prior art is performed.

  The difference between the configuration of FIG. 1 and the conventional configuration is the configuration of the portion where the discharge pipe 16 is joined to the upper end plate 22. The joint portion will be described with reference to FIG.

FIG. 2 is a cross-sectional view showing a state where the discharge pipe 16 is inserted into the pipe insertion hole 22a and joined to the upper end plate 22 by brazing.

  As shown in FIG. 2, the discharge pipe 16 has a configuration having a diameter d0 portion and a mortar-shaped different-diameter portion 16a having diameters d0 to d2. The diameter d1 of the tube insertion hole 22a is slightly larger than the diameter d0 portion of the discharge tube 16, and is smaller than the different diameter portion 16a.

  The discharge tube 16 having this cross section is inserted into the tube insertion hole 22a from the inside, and is brazed and joined in a state where the different diameter portion 16a is in contact with the inner end of the tube insertion hole 22a.

  When a high pressure is applied to the inside of the shell shell 21, a force in the direction of peeling from the upper end plate 22 acts on the discharge pipe 16 (upward in the figure). However, the different diameter portion 16a acts as a stopper. The joining force is remarkably improved as compared with the case of only the joining portion 31a.

  Therefore, by using this configuration, it is possible to easily obtain a sufficient joint strength at the joint portion between the discharge pipe 16 and the upper end plate 22 by brazing, which has conventionally not been able to obtain a sufficient joint strength.

  Moreover, as shown in FIG. 3, you may use the structure by which the different diameter part 16a of the discharge pipe 16 is accommodated in the pipe insertion hole 22a, and is joined. That is, in FIG. 3, the cross section of the tube insertion hole 22 a is configured along the different diameter portion 16 a of the discharge tube 16. Even if such a configuration is used, it is possible to easily obtain a sufficient joint strength in a joint portion by brazing, which has not been able to obtain a sufficient joint strength conventionally.

  The cross-sectional shape of the tube insertion hole 22a is such that a mortar-shaped cross section having a diameter d3 can be formed with a chamfering drill or the like having a diameter d1 formed by a drill or the like and inclined from the inner surface. It can also be formed by using press working. That is, when punching a hole in a steel plate having a thickness of 5 mm or more by press working as in this embodiment, the clearance between the press mold convex and concave molds is made somewhat larger so The side (right side of the figure) is pulled out with a diameter d1, but on the downstream side in the punching direction (left side of the figure), the maximum stress is applied outside d1 due to the stress relationship. A cross-sectional shape having a mortar shape having a diameter d1 to a diameter d3 can be formed. According to this pressing method, the tube insertion hole 22a having the above-mentioned cross-sectional shape can be easily formed, so that productivity can be improved.

  In the first embodiment, the joint between the discharge pipe 16 and the upper end plate 22 has been described. However, the present invention is not limited to this, and the above configuration is also applied to the joint between the suction outer pipe 24 and the trunk shell 21. A similar effect can be realized.

  As described above, according to the configuration of the first embodiment, the suction outer pipe 24 or the discharge pipe 16 that allows the refrigerant that is the working gas to flow in or out with a simple configuration by brazing is securely connected to the trunk shell 21 or Since it can be firmly joined to the upper end plate 22, it is possible to prevent breakage of the joint and gas leakage even when operating with a refrigerant having a high operating pressure such as CO 2. The reliability of the mold compressor can be improved.

  In the first embodiment, the different diameter portion is provided in the shape of a mortar. However, if the cross-sectional shape is a shape that can function as a stopper as described above, the same operation as in the above example is performed. Needless to say, the same effect can be obtained because it can be realized and the bonding strength can be improved. Moreover, although the cross-sectional part of the tube insertion hole 22a in FIG. 3 is a mortar shape, this shape is not limited to this, and the same effect can be realized if the shape is close to the different diameter portion shape 16a of the discharge pipe 16.

(Embodiment 2)
Next, Embodiment 2 of the present invention will be described with reference to FIG. FIG. 4 shows a longitudinal sectional view of a main part in the second embodiment of the present invention. The components are the same as in FIG.

  The difference from the first embodiment is the installation angle of the discharge pipe 16. FIG. 4 shows a configuration in which the discharge pipe 16 is installed in the same direction as the center of the cylinder of the shell shell 21. In this case, if the pipe insertion hole 22a is provided on the curved surface of the upper end plate 22, the pipe insertion hole 22a is geometric. It becomes a long hole and does not become circular. When such a tube insertion hole 22a is formed by a press, a drill, or the like, the tool of the press die is struck by a piece of the press die, and manufacturing problems and the life of the tool such as the press die are shortened.

  In order to cope with these problems, in the second embodiment, the discharge pipe 16 is inclined at an angle α as shown in FIG. The axis B is configured to be substantially vertical (α≈90 °). The discharge pipe 16 has a cross-sectional shape similar to that in FIG. 2 and has a portion having a diameter d0 and a mortar-shaped portion having a diameter from d0 to d2. When brazed and joined, the discharge pipe 16 has a different diameter as in FIG. Since the part 16a acts as a stopper, the joining strength of the discharge pipe 16 is sufficiently ensured.

  According to the above configuration, when the tube insertion hole 22a is formed by pressing, the press die hits perpendicularly to the upper end plate 22 to be pressed, and damage to the press die is reduced. Can be long.

  In addition, since the discharge pipe 16 is inclined to the opposite side of the introduction terminal 25 as in this configuration, the distance from the introduction terminal 25 or the terminal cover 26 (t5 in the figure) can be increased, so that workability is improved. Has an effect. Therefore, productivity can be improved.

  Moreover, as shown in FIG. 5, you may use the structure by which the different diameter part 16a of the discharge pipe 16 is accommodated in the pipe insertion hole 22a, and is joined. That is, in FIG. 5, the cross section of the tube insertion hole 22a is configured along the different diameter portion 16a of the discharge tube 16, and since the different diameter portion 16a is brazed and acts as a stopper, conventionally, It is possible to easily obtain a sufficient joint strength at a joint portion by brazing in which a sufficient joint strength cannot be obtained.

  In the first and second embodiments, the electric motor 7 has been described as an example of a configuration that is accommodated in a space to which the pressure of the discharge gas is applied. However, since the bonding strength is improved, the lower pressure is naturally sealed. Even the configuration in the container 1 can be used without any problem. That is, even if the pressure applied from the inner wall of the hermetic container 1 is higher than the pressure of the suction gas, the same effects as those of the first and second embodiments can be obtained.

  In the first and second embodiments, the case where the CO2 refrigerant is used has been described as an example. However, the present invention is not limited to the CO2 refrigerant, and a refrigerant whose operating pressure is equal to or lower than the CO2 refrigerant is used. Even in this case, it goes without saying that the same effect as described above can be obtained.

  As described above, since the hermetic compressor according to the present invention can firmly join the gas pipe to the hermetic container, a highly reliable hermetic compressor can be realized. It can be applied to the use of a hermetic compressor with a high pressure.

1 is a longitudinal sectional view of a hermetic compressor according to a first embodiment of the present invention. Sectional drawing of the principal part by Embodiment 1 of this invention Cross-sectional view of another example of discharge pipe joint Sectional drawing of the junction part of the discharge pipe by Embodiment 2 of this invention Cross-sectional view of another example of discharge pipe joint Longitudinal sectional view of a conventional scroll compressor Cross-sectional view of conventional main part

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Compression mechanism 6 Orbiting scroll 7 Fixed scroll 11 Suction pipe 16 Discharge pipe 21 Trunk shell 22 Upper end plate 22a Pipe insertion hole 23 Bottom end plate 24 Inhalation outer pipe 25 Introduction terminal 31 Joint part

Claims (5)

An airtight container, a compression mechanism that is provided in the airtight container and sucks and compresses the working gas, a drive shaft that drives the compression mechanism, an electric motor that rotationally drives the drive shaft, A gas pipe that is fitted and joined to a pipe insertion hole provided in the partition wall by brazing, and that allows the working gas to flow into or out of the sealed container. The gas pipe is a circular pipe, and is partially circular A hermetic compressor characterized in that a deformed portion having an outer diameter larger than that of the pipe portion is provided, and the different diameter portion is disposed on the inner side of the joint portion or the joint portion with the tube insertion hole. The hermetic compressor according to claim 1, wherein the electric motor is provided in a pressure space that is equal to or higher than a pressure of the working gas discharged from the compression mechanism. 3. The hermetic compressor according to claim 1, wherein a gas pipe is provided on a mirror plate of the partition wall, and an axis of the gas pipe is provided substantially in parallel with a normal line of the end plate. The hermetic compressor according to any one of claims 1 to 3, wherein the working gas contains carbon dioxide as a main component. The hermetic compressor according to any one of claims 1 to 4, wherein the compression mechanism section is of a scroll type.

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