JPH09112451A - Enclosed compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent support members from being corroded in the case of using an alternate refrigerant together with an ester oil by forming an anti-acid treated layer on the surface of support members for supporting bearings to support the end part on the side not connected to the compressing mechanism of a drive shaft. SOLUTION: A compression mechanism 2 in which mixed refrigerant obtained by mixing together at least one kind of refrigerant from among fluorohydrocarbon series refrigerant group is used and ester oil 7 having compatibility with mixed refrigerant is sealed inside of a tightly closed container 1, is provided. An oil pump 17 for supplying ester oil 7 to each mechanically sliding part and an electric motor 3 for driving those components by means of a crank shaft 6 are provided and the end part of a crank shaft 6 not connected to a compression mechanisms 2 is supported by a rolling bearing 12 supported in a space toward an auxiliary bearing member 11 by means of washer 43, 44. In this case, a nitrided layer 45 servicing as an anti-acid treated layer is formed on the surfaces of washers 43, 44. Thus, washers are prevented from being corroded even if they touch fatty acid. In addition, the anti-acid treated layer may be either nitrided chromium layer or resinous material layer etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic compressor mainly used in a refrigerating cycle, and more particularly, as a refrigerant, a mixed refrigerant in which at least one kind or a combination of two or more kinds of fluorocarbon-hydrogen type refrigerants is mixed, that is, The present invention relates to a hermetic compressor suitable when using an alternative refrigerant.

[0002]

2. Description of the Related Art In general, a hermetic compressor is constructed by enclosing an oil compatible with the mixed refrigerant in a hermetic container, sucking the refrigerant and compressing the oil, and a sliding mechanism for each oil. Is provided with an oil pump and an electric motor that drives these with a drive shaft. In addition to the radial type rolling bearings and sliding bearings that support the force generated on the drive shaft when the refrigerant is compressed by the compression mechanism, the thrust bearing that supports thrust load to the extent that rattling in the axial direction of the drive shaft is prevented. A section is also provided.

Since the radial bearing is particularly heavily loaded, it is provided at a plurality of positions in the axial direction of the drive shaft. The radial type rolling bearing that supports the end of the drive shaft that is not connected to the compression mechanism is supported between the fixed member and the iron-based metal support member provided on the drive shaft to provide the necessary support function. It is exerting.

On the other hand, a specific CFC R12 or a designated CFC R22 was used as the refrigerant. Compared with the previous refrigerants such as sulfur dioxide and methyl chloride, Specified Freon is chemically stable, has no flammability and toxicity, is widely used as an ideal refrigerant, and has been used for many years.

Recently, however, it has been confirmed that a specific CFC contains a chlorine atom in the molecule, which causes the destruction of the ozone layer, and the development and use of a CFC alternative have been attempted.

As a highly practical alternative refrigerant, chlorine-free HFC (Hydro Fluoro Carbo) is used.
n) "Hydraulic and pneumatic technology '9"
4.6. (Published by Nippon Kogyo Shuppan).

By the way, since the alternative refrigerant does not contain chlorine, it cannot be expected to have the lubricity as in the conventional specific CFC. Therefore, the oil to be sealed in the closed container is particularly required to be compatible with the alternative refrigerant. The oil enclosed in the airtight container is agitated by the alternative refrigerant discharged from the compression mechanism into the airtight container and also by the rotor of the electric motor. At this time, since the oil is compatible with the alternative refrigerant, it often accompanies the refrigerant discharged into the closed container and covers the details of the sliding parts of each machine well. Performance is improved.

[0008]

However, when the hermetic compressor is operated under the above conditions and the refrigeration cycle is executed, the supporting member of the rolling bearing may be corroded to generate sludge. Sometimes In such a case, operation failure may be caused, and a maintenance-free hermetic compressor is a problem particularly in reliability.

As a result of various experiments and examinations,
It was found that this was due to the use of ester oil as the oil compatible with the alternative refrigerant. If water enters when the airtight container is closed, or if water is generated for some reason after the airtightness, the ester oil is hydrolyzed by this water to produce a fatty acid. The support member is corroded by this fatty acid to produce sludge.

An object of the present invention is to solve the above problems, and even if an alternative refrigerant is used together with an ester oil compatible therewith, the supporting member of the bearing is not corroded and the hermetic compressor is highly reliable. It is intended to provide.

[0011]

The inventions of claims 1 and 6 are as follows:
As the refrigerant, a mixed refrigerant in which at least one kind or two or more kinds are mixed in the fluorocarbon-hydrogen-based refrigerant group is used, and an oil compatible with the mixed refrigerant is enclosed in a closed container,
A compression mechanism that draws in and compresses the refrigerant, an oil pump that supplies the oil to each mechanical sliding portion, and an electric motor that drives these by a drive shaft are arranged, and the compression mechanism of the drive shaft is not connected. In a hermetic compressor in which a bearing that supports an end portion is supported between a fixed member and a support member provided on a drive shaft, the invention of claim 1 particularly provides the surface of the support member with an acid-resistant treatment. Are formed in layers,
The oil compatible with the alternative refrigerant is an ester oil, which produces a fatty acid by hydrolysis, and even if the fatty acid comes into contact with the supporting member of the bearing, the surface of the supporting member is corroded due to the acid-resistant treatment layer. No sludge is generated, and the required strength is satisfied with a conventional material, for example, a ferrous metal supporting member, so that the reliability is high.

According to a sixth aspect of the present invention, in particular, the support member is made of ceramics, and the oil compatible with the alternative refrigerant is an ester oil, which produces a fatty acid by hydrolysis, which supports the bearing. Even if the member is touched, since the supporting member is a ceramic having acid resistance, it is not corroded, no sludge is generated, and mechanical strength comparable to that of the conventional metallic supporting member is obtained, so that the reliability is high. Will be things. Further, the parts can be easily manufactured at low cost by molding, and it is advantageous when it is desired to form various shapes.

In the invention of claim 1, the acid-resistant treated layer formed on the surface of the support member is a nitride layer in the invention of claim 2, a chromium nitride layer in the invention of claim 3, and the invention of claim 4. The invention is a resin material layer, the invention of claim 5 is a ceramic layer, and any of the inventions achieves the invention of claim 1.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the hermetic compressor of the present invention will be described below with reference to the drawings.

(First Embodiment) A first embodiment of the present invention shown in FIGS. 1 to 3 is a hermetic compressor used in a refrigeration cycle. The whole is shown in FIG. 1. As the refrigerant, a mixed refrigerant obtained by mixing at least one kind or two or more kinds in the fluorocarbon-hydrogen-based refrigerant group is used, and is compatible with the mixed refrigerant inside the closed container 1. A compression mechanism 2 that encloses an ester oil 7 as a certain oil and sucks and compresses a refrigerant.
And an oil pump 17 for supplying the oil 7 to each mechanical sliding portion and an electric motor 3 for driving them by a crankshaft 6 which is a drive shaft, and a side of the crankshaft 6 which is not connected to the compression mechanism 2. The rolling bearing 12 as a bearing for supporting the end portion of the washer 43 provided on the crankshaft 6 as shown in FIG.
It is supported by 44 between the auxiliary bearing member 11 which is a fixed member. Particularly, on the surfaces of the washers 43 and 44, as shown in FIG. 3, a nitride layer 45 as an acid resistant layer is formed. As the rolling bearing 12, other types may be adopted, and the supporting member other than the washers 43 and 44 achieves the necessary support, and the present invention is applicable as long as it has the object of the present invention. Be subject to.

Such a supporting structure is suitable for the case of the hermetically sealed container 1 which constitutes a horizontal type pressure container as in the present embodiment shown in FIG. However, the present invention is not limited to the horizontal type, and can be applied to the vertical type.

Specifically, in correspondence with the horizontal type,
A compression mechanism 2 is provided on one end side inside the closed container 1. The stator 4 of the electric motor 3 that drives the compression mechanism 2 is located in the central portion of the closed container 1 and is fixed to the inner surface of the side wall of the closed container 1, and the rotor 5 corresponding to the stator 4 of the electric motor 3 is attached to the rotor 5. Is arranged so that the crankshaft 6 is connected and the axis line thereof is substantially horizontal. The lower part of the closed container 1 on the end side from the auxiliary bearing member 11 is an oil reservoir 7a, and the upper part is a discharge chamber 21 for discharging the refrigerant gas to the outside of the closed container 1, and the lubricating oil reservoir 7 of the auxiliary bearing member 11 is covered. The oil pump 17 driven by the other end of the crankshaft 6 is provided on the side where the rotation is performed and is screwed. The oil pump 17 has a suction port 17a opened in the lubricating oil reservoir 7a, and a discharge port 17b communicated with a lubricating hole 6a formed longitudinally in the crankshaft 6.

A main shaft 8 is provided at an end portion of the crankshaft 6 which is connected to the compression mechanism 2, and the main shaft is supported by a main bearing member 10 fixed in the closed container 1 via a slide bearing 9. The compression mechanism 2 is arranged on the outer side of the bearing member 10 and is fixed with a screw. The sub-bearing member 11 fits a rolling bearing 12 into a recess 11a formed by sheet metal working to hold the outer circumference of the outer ring 12a of the rolling bearing 12, and receives the outer ring 12a from the compression mechanism 2 side. On the other hand, the washers 43 and 44 come into contact with the compression mechanism 2 side of the snap ring 13 fitted in the annular groove 6b of the crankshaft 6 to receive the inner ring 12b of the rolling bearing 12 from the side opposite to the compression mechanism 2. ing. By receiving the outer ring 12a and the inner ring 12b from opposite sides, the rolling bearing 12 is fixed to the crankshaft 6
Holds in the axial direction of.

The number of washers 43 and 44 may be one for holding the bearing as described above. In this embodiment, by providing the two washers 43 and 44, the metal wave washer 15 is sandwiched between the two washers 43 and 44, and the wave washer 15 is charged in the axial direction to give an elastic force.

The sliding bearing 9 and the rolling bearing 1 described above
Reference numeral 2 supports the force generated in the crankshaft 6 when the compression mechanism 2 compresses the refrigerant by the rotational movement of the crankshaft 6, and the rolling bearing 12 receives a particularly large load, but is stabilized by the support structure. Rotation is ensured, and the elastic force of the corrugated washer 15 suppresses vibration of the crankshaft 6 in the axial direction.

The main shaft 8 of the crankshaft 6 is provided with a slider 46 for slidingly driving the compression mechanism 2 in a radial direction, and the lubricating hole 6a extends from the discharge port 17b to a portion of the slider 46. Has reached. The oil discharged by the oil pump 17 is first supplied to the sliding bearing 9 and the slider 46 through the lubricating hole 6a to lubricate that portion. Further, the sliding bearing 9 portion communicates with the inside of the closed container 1 and the compression mechanism 2 through the passage 23 and the gaps between the respective portions, and is also supplied to each sliding portion of the compression mechanism 2 to lubricate them as well. .

Around the portion where the other end of the crankshaft 6 of the casing 17c of the oil pump 17 penetrates,
A thrust receiving portion 41 for the crankshaft 6 as shown in FIGS. 1 and 2A and 2B is provided to prevent axial rattling of the crankshaft 6.

The rotor 5 of the electric motor 3 is provided such that its center is located closer to the lubricating oil pump 17 than the center of the stator 4 by a predetermined amount, so that By the magnetic action of the crankshaft 6, the crankshaft 6 integrated with the rotor 5 can be pulled toward the compression mechanism 2 side, and the thrust load of the crankshaft 6 acting on the thrust receiving portion 41 can be further reduced. It is especially effective for the vertical installation type in which the weight is applied to the thrust receiving part side. But it's up to you to do this.

The compression mechanism 2 comprises a fixed scroll 2a and a movable scroll 2b. The fixed scroll 2a is screwed to the main bearing member 10 to form an end plate, which is movable between the fixed scroll 2a and the main bearing member 10. Scroll 2
b is accommodated and meshed with the fixed scroll 2a, and is supported by an Oldham ring 47 provided between the movable scroll 2b and the main bearing member 10 so that the movable scroll 2b can rotate without rotating. Then, the movable scroll 2b is fitted with the passive shaft 2c integrally formed on the movable scroll 2b on the slider 46, and is driven to rotate via the slider 46 and the Oldham ring 47 when the crankshaft 6 rotates.

Fixed scroll 2a and movable scroll 2b
Means that some of the pockets 2d are formed by mutual engagement. Movable scroll 2b
Is rotated, the pocket 2d moves to the fixed scroll 2
The refrigerant gas from the suction pipe 18 of the compressor is received when it communicates with the suction port 24 provided on the outer periphery of a, and the refrigerant gas moves toward the discharge port 19 provided at the center of the fixed scroll 2a.
Due to this movement, the volume of the pocket 2d is gradually reduced to compress the refrigerant gas being received, and the pocket 2d is compressed.
When d is communicated with the discharge port 19, it is discharged. The discharged refrigerant gas is discharged from the discharge port 19 into the closed container 1, reaches the discharge chamber 21 via the electric motor side passage 20, and is discharged to the outside of the compressor through the discharge pipe 22 provided in the discharge chamber 21. It

With this, when the compression mechanism 2 operates by the rotational movement of the crankshaft 6, the refrigerant gas is sucked and compressed repeatedly, and the refrigeration cycle can be executed.

As the refrigerant gas, a mixed refrigerant obtained by mixing at least one kind or two or more kinds in the fluorocarbon-hydrogen type refrigerant group is adopted as an alternative refrigerant, and since it does not contain chlorine, it does not damage the environment. As a specific example of such a refrigerant, HFC or FC having a boiling point close to that of the specified chlorofluorocarbon HCFC22 can be considered.

On the other hand, the oil 7 is an ester oil compatible with the refrigerant gas, and the oil 7 supplied to the compression mechanism 2 is used.
The oil that has flowed out of the sliding bearing 9 into the closed container 1 is agitated by the refrigerant that is sucked into the compression mechanism 2, compressed, and discharged into the closed container 1, and is also disturbed by the rotor 5 of the electric motor 3. And is accompanied by the refrigerant. Specific examples of such ester oils include fatty acid esters and carbonic acid esters.

When the oil 7 accompanies the refrigerant, the refrigerant flowing toward the discharge chamber 21 through the electric motor side passage 20 contains the oil 7. The oil 7 is carried by its own flow and supplied to the rolling bearing 12. Therefore, it can be lubricated appropriately. The discharge chamber 21 is formed by partitioning the inside of the closed container 1 by a baffle plate 25, and the refrigerant that is about to flow into the discharge pipe 22 collides with the baffle plate 25 to perform gas-liquid separation, and is contained in the refrigerant. The oil 7 is appropriately separated and collected in the lower oil sump 7a.

By the way, the oil 7 is an ester oil, and if water enters when the hermetically sealed container 1 is sealed or water is generated for some reason after sealing, the oil 7 is hydrolyzed by the water. The fatty acids are received to generate fatty acids, which may also touch the surfaces of the washers 43 and 44 that are the supporting members.

However, as mentioned above, since the nitride layer 45 as the acid-resistant treated layer is formed on the surface and has the acid resistance, it is not corroded even when it is contacted with fatty acid, and no sludge is generated. Since the required strength is satisfied by the conventional material, for example, the iron-based metal supporting member as in the case of the present embodiment, the reliability is high.

To form the nitride layer 45, for example, in an ammonia gas atmosphere, at a temperature of 500 ° C. to 600 ° C., 1
It is recommended to heat for 100 to 100 hours. The higher the processing temperature is, the higher the hardness of the nitride layer 45 is, and the life of the nitride layer 45 can be extended. Therefore, the surface hardness can be adjusted by setting the processing temperature.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention. This is a hermetic compressor having a structure similar to that of the first embodiment, in which a chromium nitride layer 51 is formed on the surfaces of washers 43 and 44 which are support members. Since this chromium nitride layer 51 also has acid resistance, it exhibits the same effect as that of the first embodiment. Further, since the chromium nitride layer 51 is also excellent in hardness and wear resistance, the life can be further extended in this respect as well.

The chromium nitride layer 51 can be formed by physical vapor deposition.

(Third Embodiment) FIG. 5 shows a third embodiment of the present invention. This is a hermetic compressor having a structure similar to that of the first embodiment, in which ceramic layers 53 are formed on the surfaces of washers 43 and 44 which are support members.
Is formed. Since this ceramic layer 53 also has acid resistance, it exhibits the same effects as those of the first embodiment. Further, since the ceramic layer 53 has high hardness and excellent wear resistance, the life of the ceramic layer 53 can be further extended in this respect. The ceramic layer 53 can be formed by physical vapor deposition.

(Fourth Embodiment) FIG. 6 shows a fourth embodiment of the present invention. This is a hermetic compressor having a structure similar to that of the first embodiment, in which a resin material layer 54 is formed on the surfaces of washers 43 and 44 which are support members. Since this resin material layer 54 also has acid resistance, it exhibits the same operational effect as that of the first embodiment. Further, the resin material layer 54 can be formed easily and inexpensively by coating or insert molding, which is advantageous for cost reduction.

In each embodiment, the washers 43,
An acid-resistant treated layer is provided only on 44 or the whole is made of an acid-resistant material, but similar measures can be taken for other members such as corrugated washers, if necessary.

(Fifth Embodiment) FIG. 7 shows a fourth embodiment of the present invention. This is a hermetic compressor having a structure similar to that of the first embodiment, and replaces washers 43 and 44, which are support members, with those made of ceramics. Therefore, since the washers 43 and 44 themselves have acid resistance, they are not corroded, sludge is not generated, and mechanical strength comparable to that of the conventional metal supporting member is obtained, so that it is highly reliable. Becomes Further, the parts can be easily manufactured at low cost by molding, and it is advantageous when it is desired to form various shapes.

In each embodiment, the washers 43,
An acid-resistant treated layer is provided only on 44 or the whole is made of an acid-resistant material, but similar measures can be taken for other members such as corrugated washers, if necessary.

[0040]

According to the first aspect of the present invention, the oil compatible with the alternative refrigerant is an ester oil, which produces a fatty acid by hydrolysis, and even if the fatty acid touches the supporting member of the bearing,
Since the surface of the supporting member does not corrode due to the acid-resistant treatment layer, sludge does not occur, and the supporting strength of the conventional material, for example, a ferrous metal supporting member, also satisfies the required strength. It will be highly responsive.

The acid-resistant treated layer formed on the surface of the supporting member is a nitride layer in the invention of claim 2, a chromium nitride layer in the invention of claim 3, and a resin material layer in the invention of claim 4. The invention of claim 5 is a ceramic layer, and any of the inventions achieves the invention of claim 1.

According to a sixth aspect of the present invention, the oil compatible with the alternative refrigerant is an ester oil and produces a fatty acid by hydrolysis, and even if the fatty acid comes into contact with the supporting member of the bearing, the supporting member has acid resistance. Since it is a ceramic, it is not corroded, no sludge is generated, and mechanical strength comparable to that of a conventional metal supporting member is obtained, so that it is highly reliable. Further, the parts can be easily manufactured at low cost by molding, and it is advantageous when it is desired to form various shapes.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a hermetic compressor according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the compressor of FIG.

3 is an enlarged cross-sectional view of the washer of FIG.

FIG. 4 is an enlarged cross-sectional view of a washer of a hermetic compressor showing a second embodiment of the present invention.

FIG. 5 is an enlarged sectional view of a washer of a hermetic compressor showing a third embodiment of the present invention.

FIG. 6 is an enlarged sectional view of a washer of a hermetic compressor showing a fourth embodiment of the present invention.

FIG. 7 is an enlarged sectional view of a washer of a hermetic compressor showing a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 airtight container 2 compression mechanism 3 electric motor 6 crankshaft 7 oil 11 sub-bearing member 12 rolling bearing 17 oil pump 44, 45 washer 46 nitride layer 51 chromium nitride layer 53 ceramics layer 54 resin material layer

Claims (6)

[Claims] 1. A mixed refrigerant prepared by mixing at least one kind or two or more kinds selected from the group of fluorocarbon-hydrogen based refrigerants as a refrigerant, and enclosing an oil compatible with the mixed refrigerant inside a closed container, A compression mechanism that draws in and compresses the refrigerant, an oil pump that supplies the oil to each mechanical sliding portion, and an electric motor that drives these by a drive shaft are arranged, and the compression mechanism of the drive shaft is not connected. In the hermetic compressor in which the bearing that supports the end portion is supported between the fixed member and the support member provided on the drive shaft, an acid-resistant treatment layer is formed on the surface of the support member. A hermetic compressor. 2. The acid-resistant treated layer is a nitride layer.
A hermetic compressor according to item 1. 3. The hermetic compressor according to claim 1, wherein the acid-resistant treated layer is a chromium nitride layer. 4. The hermetic compressor according to claim 1, wherein the acid-resistant treated layer is a resin material layer. 5. The hermetic compressor according to claim 1, wherein the acid-resistant treated layer is a ceramic layer. 6. A mixed refrigerant prepared by mixing at least one kind or two or more kinds selected from the group consisting of fluorocarbon-hydrogen-based refrigerants is used as a refrigerant, and an oil compatible with the mixed refrigerant is enclosed in a closed container, A compression mechanism that draws in and compresses the refrigerant, an oil pump that supplies the oil to each mechanical sliding portion, and an electric motor that drives these by a drive shaft are arranged, and the compression mechanism of the drive shaft is not connected. A hermetic compressor in which an auxiliary bearing that supports an end is supported between a fixed member and a supporting member provided on a drive shaft, wherein the supporting member is made of ceramics. Machine.