JPH10103241A - Sealed type compressor and refrigerator which uses it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform stable operation for a long time even if HFC refrigerant is used by using epoxy composed of glycidyl ether as refrigerator oil or ether lubricating oil to which carbodiimide is added. SOLUTION: Polyvinyl ether oil represented by a formula (wherein, R1 to R3 denote hydrogen atom each or hydrocarbon group having the number of carbons of 1 to 8, and they may be the same or different. R4 denotes a hydrocarbon group having the number of carbons of 1 to 4. n is an integer of 1 or more.) is used as basic oil. Preferably, epoxy composed of glycidyl ether of 0.01 to 10weight% or carbodiimide is added to this ether oil. Since the effect of additive does not appear if an amount of the additive is less than the above-mentioned scope, thermal and chemical stability is deteriorated. On the other hand, if the amount of additive exceeds the scope, the additive may be polymerized, turn into sludge, and be deposited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic compressor and a refrigeration system using the same, and more particularly, to 1,1,1,2-tetrafluoroethane (hereinafter referred to as R) as a refrigerant.
134a) alone or a mixed refrigerant of R134a, difluoromethane (hereinafter R-32) and pentafluoroethane (hereinafter R-125), R-32 and R-1
The present invention relates to an HFC-based refrigerant such as a refrigerant mixed with H.25, a hermetic electric compressor using a refrigerating machine oil compatible with the refrigerant, and a refrigeration apparatus using the same.

[0002]

2. Description of the Related Art Compressors for refrigerators, vending machines and showcases have conventionally used a large amount of dichlorodifluoromethane (hereinafter referred to as R12) as a refrigerant. This R12
Due to its high ozone depletion potential, it is subject to Freon regulations because of its problem of destroying this ozone layer when it is released into the atmosphere and reaches the ozone layer above the earth. This destruction of the ozone layer is caused by chlorine groups (Cl) in the refrigerant. Therefore, refrigerants containing no chlorine group, for example, R32, R125, R134a, or a mixture thereof are considered as substitute refrigerants, and R134a or the like as a substitute refrigerant for R12 is being studied for refrigerators (for example, See Japanese Patent Application Laid-Open No. 1-271491).

In addition, chlorodifluoromenter (R22) is conventionally used as a refrigerant in air conditioners and the like. However, HFC-based refrigerants have also attracted attention from the viewpoint of the environmental problem of destruction of the ozone layer.

[0004]

However, the above-mentioned HFC-based refrigerants such as R134a have poor compatibility with currently used refrigerating machine oils such as mineral oils and alkylbenzene oils, and deteriorate the return of oil to the compressor. In addition, there is a problem ranging from suction of the separated refrigerant at the time of start-up of the bed to poor lubrication of the compressor.

[0005] For this reason, the present inventors have proposed that H such as R134a
Ester oil was studied as a refrigerating machine oil compatible with FC refrigerant. However, when this ester-based oil is used in a compressor, the temperature tends to rise due to friction and wear of the sliding members inside the compressor, and the ester oil is hydrolyzed by the heat or decomposed by the action of iron oxide or the like. As a result, fatty acids and metal soaps are produced, causing the sliding members to corrode due to the fatty acids and the like, and a sludge component being generated due to abrasion to clog capillary tubes and the like. The oligomers are extracted from organic materials such as plastic insulating film interposed between the iron core of the stator and the magnet wires (main coil and sub-coil) and are adversely affected by hydrolysis, etc. There was a problem that the durability was impaired.

[0006] The first object of the present invention is to use R13 as a refrigerant.
Even if an HFC-based refrigerant such as 4a is used, the generation of carboxylic acid due to the thermal decomposition or hydrolysis of the refrigerating machine oil due to the frictional heat of the sliding member, and the generation of sludge associated therewith are suppressed. There is no clogging of the capillary tube etc. by the sludge, and there is no problem such as the adverse effect on the organic material such as the plastic insulating film of the electric element of the compressor.
To provide a high-performance hermetic compressor excellent in durability and capable of operating stably for a long period of time, and a second object of the present invention is to provide a refrigeration apparatus using the hermetic compressor. That is.

[0007]

Means for Solving the Problems The present inventors used an HFC-based refrigerant as a refrigerant and combined an ether-based oil having a higher hydrolysis resistance than an ester-based oil as a refrigerating machine oil compatible with the HFC-based refrigerant. As a result of repeated research for use in compressors, thermal decomposition and hydrolysis of ether-based oil due to frictional heat generated in the sliding member due to a limited combination of ether-based oil, a specific additive, and a specific plastic insulating film. The inventors have found that decomposition is suppressed and deterioration of the plastic insulating film is also suppressed, and the present invention has been completed.

According to the first aspect of the present invention, an electric motor having a rotating shaft on the lower side in a closed container, and a reciprocating compressor driven by the rotating shaft of the electric motor on the upper side are housed and sucked. A hermetic compressor in which an HFC-based refrigerant or a refrigerant mainly composed of an HFC-based refrigerant is compressed by the reciprocating compression section and discharged out of the hermetic container, and epoxy or carbodiimide made of glycidyl ether is used as a refrigerating machine oil. Polyester coated with carbodiimide as a plastic insulating film between the iron core of the stator of the electric motor unit and the main coil and the sub-coil, and between the main coil and the sub-coil, using the added ether lubricating oil. It is a hermetic compressor characterized by using a film.

According to a second aspect of the present invention, in the hermetic compressor according to the first aspect, the insulating film is a polyester film laminated with a carbodiimide resin.

According to a third aspect of the present invention, there is provided a condenser for condensing and liquefying the refrigerant according to the first aspect, a capillary tube for adjusting the pressure of the refrigerant, an evaporator for evaporating the liquefied refrigerant,
A refrigerating apparatus including an accumulator and a hermetic compressor that compresses the evaporated refrigerant and discharges the refrigerant to a condenser, wherein the hermetic compressor according to claim 1 is used as the hermetic compressor. Is a refrigeration apparatus.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The ether lubricating oil used as a base oil in the present invention is not particularly limited. Specifically, for example, a polyvinyl ether-based oil represented by the following general formula (1) can be preferably used. In the formula, R _{1 to} R ₃ each represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, which may be the same or different. R ₄ represents a hydrocarbon group having 1 to ₄ carbon atoms. n is an integer of 1 or more.

[0012]

Embedded image

[0013] 0.01 to 10 to the ether oil
It is preferable to add an epoxy composed of glycidyl ether by weight, but if it is less than this range, the effect of the epoxy will not be exhibited, resulting in poor thermochemical stability. If it exceeds this range, the epoxy may polymerize, become sludge and deposit. The preferred addition range of the epoxy to the ether oil is 0.1 to 2.0% by weight.

It is preferable to add 0.01 to 10% by weight of carbodiimide with respect to the ether oil, but if it is less than this range, the effect of carbodiimide will not be exhibited, resulting in poor thermochemical stability. If the amount exceeds this range, carbodiimide may polymerize, form sludge and accumulate, or deteriorate stability. The preferred range of addition of carbodiimide to the ether oil is 0.1 to 2.0% by weight, more preferably 0.05 to 0.5% by weight.

It is preferable to add a phenolic antioxidant as an additive to the ether-based oil in order to prevent oxidative deterioration during long-term storage.
%, More preferably 0.05 to 0.3% by weight. As antioxidants, 2,6-di-t-butyl-paracresol, 2,6-di-t-butyl-phenol,
2,4,6-tri-t-butyl-phenol and the like can be used.

It is preferable that a benzotriazole-based copper deactivator is added to the ether oil if necessary, and the amount thereof is 1 to 100 ppm, more preferably 5 to 100 ppm.
５０50 ppm. As the benzotriazole-based copper deactivator, for example, specifically, 5-methyl-1H-benzotriazole, 1-dioctylaminomethylbenzotriazole and the like can be used.

Other known additives may be added to the ether-based lubricating oil composition without departing from the gist of the present invention.

The epoxy glycidyl ether is selected from the group of hexyl glycidyl ether, 2-ethylhexyl glycidyl ether, isooctadecyl glycidyl ether and the like.

The present invention will be described below with reference to FIGS. FIG. 1 shows a hermetic compressor a of the present invention for compressing and discharging an evaporated HFC-based refrigerant to a condenser, a condenser b for condensing and liquefying the refrigerant, a capillary tube c for reducing the pressure of the refrigerant, and a liquefied refrigerant. 1 shows an example of a refrigeration cycle of a refrigeration apparatus of the present invention in which an evaporator d for evaporating water is sequentially connected by a refrigerant pipe.

FIG. 2 is a longitudinal sectional view of an example of the hermetic compressor according to the present invention. FIG. 3 is a sectional view of the hermetic compressor of the present invention shown in FIG. In FIG. 2, reference numeral 1 denotes a closed container, in which a motor unit 2 disposed on a lower side;
The reciprocating compression unit 3 disposed on the upper side is housed. The reciprocating compression unit 3 and the electric motor unit 2 are elastically attached to the inner wall of the closed casing 1. The motor unit 2 has a winding (consisting of a main coil 18 and a sub coil 19 described later) 4 inside an iron core 5.
A stator 5 wound around A, a rotor 6 disposed inside the stator, and a rotating shaft 8 inserted into the center of the rotor and supported by bearings 7. .

The reciprocating compression section 3 includes a cylinder 9, a piston 11 reciprocating in the cylinder by being fitted to a crankpin 10 of a rotary shaft 8, a valve seat 12 provided on an end face of the cylinder 9, and a And a cylinder head 13 that is attached to the cylinder 9 through the cylinder head 13. Valve seat 12
A discharge valve (not shown) for opening and closing a discharge port is attached to the cylinder head 13 side.

An HFC-based refrigerant, for example,
R134a, R32 and R125 mixed refrigerant (R4
07C) or a mixed refrigerant of two types of R32 and R125 (R410A) is inhaled, and a polyvinyl ether-based oil which is a refrigerating machine oil compatible with this refrigerant is used as a base oil,
Phosphoric acid triester composed of 0.1 to 2.0% by weight of tricresyl phosphate (TCP) or epoxy composed of 0.01 to 10% by weight of glycidyl ether or 0.01 to 10% by weight based on the base oil. An oil 14 containing carbodiimide in an amount of 10% by weight is enclosed.

In the hermetic compressor (reciprocating compressor) of the present invention using the refrigerating machine oil composition (oil 14), the HFC-based refrigerant flowing into the cylinder 9 by the reciprocating sliding of the piston 11 And is discharged to an external refrigeration cycle by opening a discharge valve (not shown).

The oil 14 placed at the bottom of the sealed container 1 fills the inside of the lubricating oil cup through the hole 16 of the lubricating oil cup 15, and has a hollow lubricating oil passage 17 in the center of the lubricating oil cup 15. The rotary shaft 8 has a rotary shaft 8, and the high-speed rotation of the rotary shaft 8 causes a vacuum phenomenon caused by a vortex generated at the upper open end, so that the oil 14 is sucked up and circulated to each sliding portion such as the piston 11 / cylinder 9 and the rotary shaft 8 / bearing 7. Self-lubrication to lubricate.

FIG. 3 is an enlarged view of a portion B of the stator 5 having the winding 4 and the iron core 5A.
A carbodiimide-coated polyester (polyethylene terephthalate) insulating film 20 is interposed between the main coil 18 and the iron core 5A and the sub coil 19, and also between the main coil 18 and the sub coil 19. The plastic insulating film 20 is interposed.

The method for producing the polyester insulating film coated with the carbodiimide is not particularly limited. Specifically, for example, when a liquid carbodiimide is used, a carbodiimide resin such as a spray coating method, an immersion method, a roll coating method, and a brushing method. When the resin film is used, a method of dry laminating the same resin film, a method of extruding the same resin film or a method of co-extruding the same resin film, and a method of laminating the same resin film using an adhesive can be used. When coating the polyester insulating film with carbodiimide, one side of the polyester insulating film may be coated, both sides of the polyester insulating film may be coated, and the surfaces coated on one side of the polyester insulating film may be uncoated. Or any one of them.

By using the polyester insulating film coated with the carbodiimide as described above, deterioration of the insulating film can be suppressed, and HFC is eluted or extracted from the insulating film.
The carbodiimide component contained in the system refrigerant also contributes to the prevention of deterioration of the ether lubricating oil.

[0028]

EXAMPLES The present invention will be described below in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. (Example 1) Hermetic compressor (exclusion volume 7.65) of the present invention
cc), a durability test was performed under the following test conditions using a refrigeration apparatus (bench stand test apparatus) of the present invention in which a condenser, an expansion valve, and an evaporator were connected by pipes, and a bearing 7, a rotating shaft 8, a cylinder 9, The degree of wear of the sliding portions of the crankpin 10 and the piston 11, the amount of sludge at a discharge valve (not shown), the hue of oil (measured by the ASTM method described in JIS K2580), the amount of oil returned to the bottom of the sealed container 1, the compressor The deterioration of the polyester insulating film 20 used for the motor unit 2 was measured. No deterioration occurred in the polyester insulating film. Table 1 shows the test results.

A in the degree of abrasion in Table 1 indicates that the wear is small and the condition is the same as that of a new article. B indicates that the abrasion is normal, and AB indicates the middle abrasion between A and B. And C shows a state of wear that is so severe that it is not practical. A in the sludge column in Table 1 indicates a state in which the amount of generated sludge is small, B indicates that the amount of generated sludge is normal, and AB indicates the amount of sludge intermediate between A and B. The state of the amount of generation is shown, and C indicates a state in which the amount of generation of sludge is too large to be practical.

Pressure conditions: high pressure 23.0 kg / cm ² ·
G, Low pressure: 1.0 kg / cm ² · G Operating frequency: 100 HZ, Operating time: 200 hr, Refrigerant: R134a Case upper temperature: 110 to 120 ° C. Polyester insulating film: Calcoat E film (P
A film in which a carbodiimide resin is coated on the surface of an ET film. (Manufactured by Nisshinbo)

Lubricating oil composition (oil): 0.05 to 0.3% by weight of 2,6-di-t-butyl-paracresol based on a polyvinyl ether-based oil (FVC68DX3, manufactured by Idemitsu Kosan Co., Ltd.) (Hue before use is L
0.5) (Prepared amount: 230 cc).

(Comparative Example 1) The results of a test performed in the same manner as in Example 1 except that no epoxy was added to the oil are shown in Table 1.
Shown in

(Comparative Example 2) Table 1 shows the results of a test conducted in the same manner as in Example 1 except that a PET film having no carbodiimide resin coated on the surface was used.

[0034]

[Table 1]

From Table 1, it can be seen that in Example 1, there was no wear on each sliding portion, the amount of sludge was small, the hue of the oil was unchanged from that at the time of preparation, and the amount of returned oil was large. On the other hand, in Comparative Example 1, wear of each sliding portion was slightly observed, and the amount of sludge exceeded the practical level. The hue of the oil was worse than at the time of preparation. In Comparative Example 2, wear of each sliding portion was slightly observed, the amount of sludge was large, and the PET film deteriorated.

3.1 g of the Calcoat E film used in Example 1 and 3.1 g of the PET film used in Comparative Example 2 were added to 50 ml of the ether-based lubricating oil used in Example 1 (initial water content: 100 ppm). Table 2 shows the results of measuring the presence or absence of precipitates and the amount of oligomer extracted from each film after the treatment for 10 days.

[0037]

[Table 2]

From Table 2, it can be seen that in the case of a PET film (Calcoat E film) coated with a carbodiimide resin on the surface, there is no precipitate and the amount of oligomer extracted is small. On the other hand, the PET film has a precipitate and a large amount of oligomer is extracted.

The Calcoat E film used in Example 1 and 3.1 g of the PET film used in Comparative Example 2 were put into 50 ml of the ether lubricating oil used in Example 1 (initial water content: 50 ppm and 100 ppm), and 175
Table 3 shows the results obtained by measuring the total acid value of each lubricating oil after treatment at 10 ° C for 10 days.

[0040]

[Table 3]

Table 3 shows that a PET film (Calcoat E film) coated on its surface with a carbodiimide resin has an effect of suppressing the deterioration of the ether-based lubricating oil. On the other hand, in the case of the PET film, the total acid value was higher than in the case of using only the ether lubricating oil.

[0042]

As described above, the hermetic compressor of the present invention and the refrigeration system using the same are constructed as described above, so that even when an HFC-based refrigerant is used and an ether-based refrigeration oil is used as the refrigeration oil, the hermetic compressor is used. The polyester insulating film used for the electric element of the compressor and the ether-based refrigerating machine oil used did not deteriorate, the wear of the sliding parts was suppressed, and there was no problem that sludge was deposited on the capillary tubes in the refrigerating circuit and clogged, It can be operated stably for a long time.

[Brief description of the drawings]

FIG. 1 is a refrigeration circuit diagram of an example of a refrigeration apparatus of the present invention.

FIG. 2 is a longitudinal sectional view of an example of the hermetic compressor of the present invention.

FIG. 3 is a sectional view of the hermetic compressor of FIG. 2 taken along line AA.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed container 2 Electric motor part 3 Reciprocating compression part 4 Winding 5A iron core 5 Stator 6 Rotor 7 Bearing 8 Rotating shaft 9 Cylinder 10 Crank pin 11 Piston 12 Valve seat 13 Cylinder head 14 Oil 15 Lubricating oil cup 16 Hole 17 Lubrication Oil passage 18 Main coil 19 Sub coil 20 Polyester insulating film

Claims (3)

[Claims] 1. A motor unit having a rotating shaft on the lower side in a closed container and a reciprocating compression unit driven by the rotating shaft of the motor unit on the upper side. A hermetic compressor in which a main refrigerant is compressed by the reciprocating compression section and discharged to the outside of the hermetic container, wherein an ether lubricating oil to which epoxy or carbodiimide made of glycidyl ether is added as a refrigerating machine oil. A polyester film coated with carbodiimide is used as a plastic insulating film interposed between the iron core of the stator of the electric motor unit and the main coil and the sub coil, and between the main coil and the sub coil. Hermetic compressor. 2. The hermetic compressor according to claim 1, wherein said insulating film is a polyester film laminated with a carbodiimide resin. 3. A condenser for condensing and liquefying the refrigerant according to claim 1, a capillary tube for adjusting the pressure of the refrigerant, an evaporator for evaporating the liquefied refrigerant, an accumulator, and compressing the evaporated refrigerant to a condenser. A refrigerating apparatus provided with a hermetic compressor for discharging and the like, wherein the hermetic compressor according to claim 1 is used as the hermetic compressor.