KR100856630B1 - Refrigerant compressor - Google Patents

Abstract

An object of the present invention is a gasket used in a refrigerant compressor, which does not use asbestos, maintains airtightness of each part sufficiently, and is also excellent in strength and durability, and does not generate precipitates or promote refrigerant oil deterioration. By using a gasket for a compressor, it is to provide a compressor with high reliability and suitable for environmental conservation.

In the refrigerant compressor in which the compression mechanism part 3 and the electric motor part 4 are accommodated in the airtight container 2 which stores refrigeration oil, the gasket 15 which seals the inside of the compression mechanism part 3 is provided, and the gasket | 15), a joint sheet containing a non-asbestos-based base fiber together with a binder and a filler was used, and was excellent in heat resistance, oil resistance and refrigerant resistance.

Refrigerant compressor, gasket, refrigeration oil, compression equipment part, electric motor part, airtight container

Description

Refrigerant Compressor {REFRIGERANT COMPRESSOR}

1 is a sectional view of a hermetic electric compressor which is a refrigerant compressor of the present embodiment.

2 is an external view of a gasket.

<Explanation of symbols for main parts of the drawings>

1: Hermetic electric compressor (Refrigerant compressor)

2: sealed container

3: compression mechanism part

4: motor part

5: frame

6: shaft

7: piston

8: cylinder

9: head cover

10: Bolt

11: spring

12: electric motor

13: stator

14: rotor

15: gasket

[Document 1] Japanese Unexamined Patent Publication No. 7-216342

The present invention relates to a refrigerant compressor such as a refrigeration air conditioning system represented by, for example, a refrigerator and a room air conditioner.

Conventionally, an asbestos joint sheet has been used as a gasket used in a refrigerant compressor. This type of asbestos joint sheet is produced by supplying a binder such as rubber and a composition for a joint sheet obtained by kneading a compounding agent between a pair of rolls and heat-compressing with asbestos as a base material. The asbestos joint sheet thus obtained is a dense and even sheet-like member and is excellent in heat resistance.

Recently, the effects of Asbestos on the human body have been pointed out. In the refrigerant compressor used in the refrigerator, the compression element is disposed in a sealed container, and asbestos is hardened by being encased in rubber, so that there is no possibility that Asbestos will scatter during actual use of the refrigerator. In addition, even when the product is disposed of, it is the subject of legal regulations such as the Household Appliances Recycling Act and is properly processed in a recycling facility, so there is no possibility of scattering to the outside.

However, in recent years when the use of asbestos is regulated worldwide, the gasket has shifted to contain no asbestos. Examples of the replacement fibers include glass fibers, mineral fibers, carbon fibers, ceramic fibers, potassium titanate fibers, wollastonite and the like. Examples of the organic fibers include aramid fibers, polyolefin fibers, polyacrylonitrile fibers, polyparaphenylene benzobisoxazole fibers and the like. As a gasket which does not use asbestos, it is described in Document 1.

However, it is pointed out that when inorganic fibers such as glass fibers and aramid fibers are used in combination with organic fibers, the inorganic fibers are pulverized when these are mixed to decrease the sealing performance as a gasket. In addition, since inorganic fibers are generally inferior in dispersibility during mixing, it is difficult to obtain a composition for forming a joint sheet in which fibers are uniformly dispersed, and a gasket obtained from a composition for forming a joint sheet in which fibers are uniformly dispersed has strength and stress. There was a problem of poor relaxation.

On the other hand, in the gasket formed by using a large amount of organic fiber as a base fiber, there exists a problem that heat resistance is inferior. In comparison with the Asbestos joint sheet, the joint sheet containing no asbestos exhibits deterioration such as hardening, decomposition and disappearance due to thermal history when the rubber component blended under high temperature and high pressure conditions. Since this falls, reliability falls.

Moreover, in the case of the combination of HFC type refrigerant | coolant / ester oil, etc., as a result of corrosion of the coupling part, such as a rubber component, durability required as a gasket of a hermetic compressor is inferior, and sealing property also becomes inadequate. In addition, sulfur and peroxide, which are unreacted vulcanized sulfur and peroxide contained in the sheet containing no asbestos, may be eluted in the refrigeration oil, thereby deteriorating the performance of the compressor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a refrigerant compressor which is suitable for environmental preservation and which maintains airtightness of the compression element, secures strength and durability, and suppresses deterioration of refrigeration oil.

In order to achieve the above object, in a refrigerant compressor in which a compressor unit and an electric motor unit are housed in a hermetically sealed container storing refrigeration oil, the present invention includes a gasket for sealing the inside of the compressor unit, and both the binder and the filler are included in the gasket. A joint sheet containing non-asbestos-based fibers and having excellent heat resistance, oil resistance and refrigerant resistance was used.

In this invention, even if it uses the gasket which consists of components other than asbestos, a precipitate does not arise and the more preferable aspect which does not accelerate deterioration of refrigerator oil is as follows.

(1) A gasket material containing 5 to 30 wt% of aramid fibers and 1 to 15 wt% of zinc oxide in the fiber component excluding the solvent as the non-asbestos base fiber.

(2) It contains 1-15 weight% of carbon black as a binder, and 50-90 weight% of inorganic materials as a filler.

(3) Any of polyalkylene glycol oil, polyol ester oil, polyalphaolefin oil, paraffinic mineral oil and naphthenic mineral oil having hydrocarbon as a refrigerant and having a viscosity of 10 to 80 mm2 / s at 40 ° C as a refrigerator oil. Using one type or two or more types in mixture.

(4) polyalkylene glycol oil, polyol ester oil, polyalphaolefin oil, paraffinic mineral oil, naphthenic mineral oil having hydrofluorocarbon as refrigerant and having viscosity of 10 to 80 mm &lt; 2 &gt; / s at 4O &lt; 0 &gt; C as refrigeration oil. Any one type or two or more types are mixed and used.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a sectional view showing a refrigerant compressor of this embodiment, and the refrigerant compressor of this embodiment is a hermetic electric compressor in which a compression mechanism portion and an electric motor portion are housed in a hermetic container. 2 is an external view of a gasket used in the present embodiment.

There are many types of compression types in hermetic electric compressors, such as rotary, scroll, and reciprocating. Moreover, also in the reciprocating system, there are many systems, such as a piston rod type and a scotch yoke type. Although Fig. 1 shows a hermetic yoke type hermetic electric compressor, the gasket used in this embodiment is not limited to the scotch yoke type.

The compression mechanism part 3 is arranged in the upper part in the airtight container 2, and the electric motor part 4 is arrange | positioned in the lower part, the stator 13 of the electric motor 12 is fixedly attached to the frame 5 with the bolt 10, In addition, the rotor 14 and the shaft 6 are connected by press fitting or shrink fitting. These are elastically supported in the closed container 2 by the spring 11.

When the hermetic electric compressor configured as described above is driven by the electric motor 12, the piston 7 reciprocates by the eccentric rotational motion of the crankshaft 6 axially supported via the rotor 14, and the cylinder ( 8) The refrigerant gas is sucked in, compressed and discharged. Here, a gasket 15 is used between the cylinder 8 and the head cover 9 to prevent leakage of refrigerant from inside the cylinder 8.

In addition, the refrigerator oil is stored in the airtight container 2. When the electric motor 12 is driven, the crankshaft 6 rotates, and the refrigeration oil is raised to the position of the compression mechanism part 3 by the pump action, and is supplied to the sliding part of the compression mechanism part 3. Therefore, the sliding parts of the cylinder 8 and the piston 7 are also lubricated and stable operation is possible. Thus, since refrigeration oil is also supplied in the cylinder 8, the gasket 15 located in the innermost part of the cylinder 8 becomes a problem not only heat resistance or refrigerant resistance but also oil resistance.

Therefore, a gasket containing various components was started and evaluated for oil resistance and strength. Table 1 shows the components of the gasket evaluated in this example.

Table 1

The gasket material shown as an Example contains 10 to 20 weight% of aramid fibers, and uses carbon black as a binder (compounding amount: 1 to 10 weight%). In addition, zinc oxide is included in an amount of 1 to 10% by weight in consideration of strength retention, and the remaining component is used as an inorganic filler. In addition, although Table 1 shows content of an inorganic filler as 60 to 80 weight%, this is a target and may be 50 to 90 weight% by content of aramid fiber, zinc oxide, or carbon black.

The first comparative example is an example in which 20% by weight of cellulose and 15% by weight of NBR latex are used, and the remaining 65% by weight is used as an inorganic filler. The second comparative example contains 1 to 10% by weight of aramid fibers and cellulose in total. It is an example which made 20 weight% latex and the remaining 70 weight% an inorganic filler.

The third comparative example is a gasket containing conventionally used asbestos, which contains 44% by weight of asbestos, 10% by weight of carbon black, and the rest as inorganic fillers. That is, the performance (heat resistance, oil resistance, etc.) of the gasket of this third comparative example is a comparison target of the performance of the gasket used for the refrigerant compressor.

Shield tube tests were performed on these examples and comparative examples. This shield tube test was performed by the method according to annex 2 of JISK2211 "Refrigerating base oil" especially for the purpose of oil-proof / refrigerant evaluation of a gasket material. As the test conditions, three sheets of a gasket processed into a dumbbell shape having a length of 50 mm, a width of 3 mm, and a thickness of 0.8 mm were put in a test tube in a test tube, and then injected with 3 g of oil and 0.5 g of a refrigerant, and sealed and heated at 130 ° C. for 40 days. After that, the color (color) of the oil, the acid value, the appearance and tensile strength of the gasket were measured.

As a representative, the combination of the refrigerant and the refrigeration oil was tested by a combination of hydrocarbon / mineral oil and a combination of hydrofluorocarbon / ester oil. R600a was used as the hydrocarbon refrigerant and R134a was used as the hydrofluorocarbon refrigerant. The acid value of the refrigeration oil after the test was in accordance with JIS K2501 "Petroleum products and lubricant-neutralization test method". In addition, the tensile strength of the gasket was performed by the method according to JIS R3453 "joint sheet".

These evaluation results are shown in Table 2.

[Table 2]

As shown in Table 2, it was confirmed that the gasket of the example could not see the influence on the deterioration of the refrigeration oil. In particular, in the first comparative example and the second comparative example, it can be seen that the aggressiveness to the ester oil is strong. Moreover, it was confirmed that the fall of intensity | strength was also small compared with the 1st comparative example and the 2nd comparative example. That is, in the evaluation of oil / refrigerant resistance, it was confirmed that this example is superior to the first and second comparative examples. Moreover, the aggressiveness with respect to ester oil was also equivalent to the 3rd comparative example. The tensile strength was slightly lower than that of the third comparative example, but it was confirmed that the gasket used between the cylinder 8 and the head cover 9 in the refrigerant compressor was of sufficient strength.

In the first and second comparative examples, a rubber component such as NBR latex is used, and the filler (plastic) in the rubber component is considered to promote oxidation of the refrigeration oil, and the gasket itself is deteriorated under the influence of the refrigeration oil. do. In this embodiment, since a gasket is formed without using NBR latex and zinc oxide is contained together with the aramid fiber, it is considered that this contributes to strength maintenance.

Regarding heat resistance, the specification temperature range of the gasket of this embodiment is -100 ° C to 180 ° C, and does not cause deterioration of the gasket itself under the current test temperature conditions. However, in order to confirm that there is no problem in an actual apparatus, when the temperature of the compressor was raised to around 115 ° C, a product assembly life test was conducted to confirm the sealability.

As the test conditions, for example, in the case of high temperature high speed continuous operation, the room temperature was 44 ° C, the rotation speed was 4900 min ⁻¹ , and the operating pressure was Pd / Ps = 0.06 / 0.9 MPa. According to this condition, the temperature of the compressor is about 115 ° C, and the temperature near the gasket is exposed to high temperature discharge gas, and thus the temperature is about 180 ° C. If 90 days of test operation are performed on this condition, it will correspond to about 10 years in normal use environment.

After performing this product assembly test, it confirmed that there was no problem of sealing property even if a compressor was removed and an air pressure load of 1 MPa was applied. In addition, the test oil was also recovered for the refrigeration oil to confirm that there was no deterioration of the refrigeration oil.

In the gasket of the present embodiment, the aramid fiber does not necessarily need to be contained in an amount of 10% by weight or more, but it is considered that it is necessary to contain 55% by weight or more except at least a solvent. In addition, it is not necessary to suppress it within 20 weight%, but it is necessary to set it as 30 weight% at the maximum. The same applies to zinc oxide, and if suppressed within 15% by weight, it is expected that the gasket used between at least the cylinder 8 and the head cover 9 in the refrigerant compressor exhibits performance without problems. Although the binder varies depending on the content of each component described above, the gasket can be obtained by setting the content of carbon black to be within 15% by weight or less and configuring the inorganic filler other than that.

In addition, in Table 2, although the result which used ester oil and mineral oil as a refrigerator oil was shown, when using the thing of this Example as a gasket of a refrigerant | coolant compressor, even if it was other refrigerator oil, it was confirmed that it is a range which does not produce a special problem. As the mineral oil, deterioration of the gasket and the refrigeration oil was hardly considered in either paraffin or naphthenic. In addition, although the same evaluation was performed using polyalphaolefin oil and polyalkylene glycol oil, also about these, the range of deterioration was limited compared with the 1st, 2nd comparative example.

By employing this gasket, deterioration of the refrigeration oil is not promoted, the drop in strength of the gasket is also suppressed, and no precipitate is generated, and a highly reliable compressor can be provided.

According to the present invention, it is possible to provide a refrigerant compressor which is suitable for environmental preservation, attains airtightness, secures strength and durability, and suppresses refrigeration oil deterioration.

Claims (5)

delete A refrigerant compressor in which a compression mechanism portion and an electric motor portion are housed in an airtight container for storing refrigeration oil, comprising: a gasket for sealing the inside of the compression mechanism portion; As the gasket, a joint sheet containing a non-asbestos-based base fiber together with a binder and a filler, and having excellent heat resistance, oil resistance and refrigerant resistance, is used. A refrigerant compressor comprising 5 to 30% by weight of aramid fiber and 1 to 15% by weight of zinc oxide as the non-asbestos-based base material as the gasket material. The refrigerant compressor according to claim 2, wherein the binder contains 1 to 15% by weight of carbon black and 50 to 90% by weight of the inorganic material as the filler. The polyalkylene glycol oil, polyol ester oil, polyalphaolefin oil and paraffin type according to claim 2 or 3, wherein hydrocarbon is used as the refrigerant and the viscosity is 10 to 80 mm 2 / s at 40 ° C as the refrigerator oil. A refrigerant compressor characterized by mixing any one kind or two or more kinds of mineral oil and naphthenic mineral oil. The polyalkylene glycol oil, polyol ester oil, polyalphaolefin oil according to claim 2 or 3, wherein hydrofluorocarbon is used as the refrigerant and the viscosity is 10 to 80 mm &lt; 2 &gt; A refrigerant compressor characterized by using any one or two or more types of paraffinic mineral oil and naphthenic mineral oil.

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