JPH0494475A - Closed compressor - Google Patents

Abstract

PURPOSE:To remove an amount of water, before a large amount of acid and harmful substance is generated, so as to prevent generation of leakage, corrosive wearing and improper cooling by providing constitution of a heater closely attached to a closed casing, and providing a control circuit for electrifying the heater. CONSTITUTION:When a motor of a closed compressor is stopped, a heater 16 is electrified by a heater electrifying control unit 16 to heat refrigerator oil. That is, water in the refrigerator oil is evaporated and held in a gas phase by heating the oil when the closed compressor is stopped. When operation of the closed compressor is started, the water in the gas phase is circulated in a system and dewatered by a drying agent in a drier. Generation of acid and harmful substance in the refrigerating system is prevented by removing the water in the refrigerator oil, and it can be prevented that the compressor is damaged by supplying acid to a sliding surface of a mechanical part 1 to generate corrosive wearing and that improper cooling is generate by packing a polymerized object in the generated harmful substance into piping of the refrigerating system.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a hermetic compressor used in refrigerators, freezers, etc.

Prior art In recent years, chlorofluorocarbons (hereinafter referred to as CFCs)
Environmental problems such as ozone layer depletion and global warming due to the effects of environmental pollution are attracting attention. From this perspective, reducing the amount of CFC refrigerant used has become an extremely important theme. The fully halogenated carbon compounds conventionally used as CFCs are being replaced by halogenated carbon compounds containing at least one hydrogen.

More specifically, dichlorodifluoromethane (hereinafter referred to as CFC-12), a typical refrigerant, is a substitute for CFC and has a low impact on ozone depletion.
1.1.2-tetrafluoroethane (hereinafter referred to as RFC-13
Various improvement efforts are being made to replace the 4&.

For example, DuPont's Re, published in October 1978.
According to the description in 5earch Disclosure,
HFC-134a has poor compatibility with any conventional oil, causing two-layer separation in all temperature ranges, and is only soluble in glycol-based oils. However, subsequent research has revealed that it is also soluble in ester oils. For example, US Pat. No. 4,851,144 shows that a mixed ester-based and glycol-based refrigerating machine oil dissolves in the refrigerant RFC-134a.

Furthermore, since HFC-134a contains a large number of hydrogen atoms, it is inherently easy to conduct electricity and has extremely poor electrical insulation properties required for hermetic compressors. However, the density of the gas phase part is about 1000 times smaller than that of the liquid phase part, so the electrical insulation is not bad.

FIG. 4 is a sectional view of a conventional hermetic compressor.

In FIG. 4, reference numeral 1 denotes a mechanical section, which consists of a shaft 2, a sub-bearing 3, a bearing 4, a piston 5, and a cylinder 6. The shaft 2, sub-bearing 3, bearing 4, piston 5, and cylinder 6 form a compression chamber 7. Reference numeral 8 denotes an oil supply device, which is composed of an oil supply pipe 9 and a spring 10 located inside the oil supply pipe and functioning as a viscous pump. 11 is refrigerant CFC-
12 and refrigerating machine oil, and the oil supply device 8 is a mixed liquid of 11 and refrigeration oil.
is supplied to the sliding surface. 12 is a motor section. 13 is a terminal section for supplying electricity to the motor section 12. Further, 14 is a metal sealed casing that houses the mechanical section 1 and the motor section 12.

Problems to be Solved by the Invention In the hermetic compressor configured as described above, the shaft 2 is rotated by the rotational force of the motor section 12, moves the piston 5, and moves the sub bearing 3, the bearing 4, and the cylinder 6.
The refrigerant in the compression chamber T formed by the refrigerant is compressed. The compressed refrigerant is liquefied in the condenser, dehydrated with a desiccant in the dryer, vaporized in the evaporator, cooled, and then returned to the compressor.

In addition, compressors like the one shown in the figure have recently been made smaller to save space, so they are often used at high temperatures where heat dissipation is poor. For this reason, even ester-based oils and glycol-based oils that have good heat resistance for boat fishing,
When impurities such as air and moisture coexist and the temperature reaches high temperatures, chemical reactions occur and produce substances that are harmful to the refrigeration system. In particular, ester oils are hydrolyzed by trace amounts of water left in the refrigerating machine oil to produce acids, and the acids produced by this reaction have a catalytic effect, producing even larger amounts of acids and harmful substances.

The generated acid then supplies oil to the sliding surfaces of the mechanical part 1, causing corrosive wear and shortening the life of the compressor. In addition, polymers among the generated harmful substances clog the pipes of the refrigeration system, resulting in poor cooling.

Of course, it is possible to deal with this by increasing the amount of desiccant in the refrigeration system, where the refrigeration oil has been previously dehydrated using an oil purifier. However, dehydration using an oil purifier has a limit, and it is not possible to remove moisture adsorbed on the surface of the refrigeration system piping or moisture retained in the tight gaps between the silicon steel plates of the nutator of the motor section 12. The water that cannot be removed gradually precipitates when a hermetic compressor is used. Therefore, a trace amount of water inevitably remains in the refrigerating machine oil. Furthermore, even if the amount of desiccant in the refrigeration system was increased, water could not be completely removed because refrigeration oil is hydrophilic.

Therefore, the hermetic compressor of the present invention encloses a refrigerant made of a halogenated carbon compound substituted with at least one hydrogen and refrigerating machine oil dissolved in the refrigerant, which decomposes and generates acid. The challenge is to provide a hermetic compressor that can detect defects before the system breaks down.

Furthermore, in recent years, small compressors such as the one shown in the figure have become more and more horizontal in order to save space, that is, the mechanical section 1 and the motor section 12 that drives the mechanical section are often installed horizontally. . That is, it has a structure in which it is immersed in a mixture of refrigerant CFC-12 and refrigeration oil. Therefore, if the refrigerant RF C-1s 4a, which has poor electrical insulation properties, is used in this compressor, the refrigerant RFC-134a will dissolve in the refrigerating machine oil in the liquid phase, and due to its poor insulation properties in the liquid phase, the motor The electricity in section 12 is passed through sealed casing 14.

Therefore, there was a possibility that there would be a risk of electrical leakage or electric shock.

Therefore, it is an object of the present invention to provide a hermetic compressor that can maintain electrical insulation even in a compressor that uses a refrigerant that contains many hydrogen atoms and is inherently easy to conduct electricity, such as RFC-134a. is the issue.

Means for Solving the Problems In order to solve the above problems, the compressor of the present invention complies with RFC-
134a, an airtight casing in which ester-based or glycol-based refrigerating machine oil is sealed, a mechanical part housed in the airtight casing, a motor part that drives the mechanical part, and an oil supply device that conveys the refrigerating machine oil to the mechanical part. In the hermetic compressor, a control circuit for energizing the heater is provided, which comprises a heater in close contact with the hermetic casing.

Further, a switching circuit is provided that allows current to flow only through the auxiliary winding of the hermetic compressor.

Further, a voltage variable device for controlling the voltage applied to the main and auxiliary windings of the hermetic compressor is provided.

Effect of the Invention With the above-described configuration, the present invention prevents failure of the refrigeration system by removing water that gradually precipitates and dissolves in the refrigerating machine oil by heat generated by electricity flowing through the heater and the hermetic compressor. Keep the refrigerant R above the specified temperature.
By limiting the amount of FC-1348 dissolved, the risk of electrical leakage or electric shock is prevented.

Embodiment Hereinafter, a compressor according to an embodiment of the present invention will be described with reference to FIG. 1. Parts that are the same as those in the conventional example will be given the same reference numerals and their explanation will be omitted.

A first embodiment will be described with reference to FIG.

16 is a heater installed in the hermetic compressor, and 16 is a control device for energizing the heater 16.

The operation of the hermetic compressor configured as above will be explained.

The shaft 2 is rotated by the rotational force of the motor section 12, moves the pinuton 5, and compresses the refrigerant in the compression chamber 7 formed by the auxiliary bearing 3, the bearing 4, and the cylinder 6. Compression heat and motor part 1 at this time? The temperature of the hermetic compressor rises due to the heat generated. Meanwhile, the compressed refrigerant is cooled in the refrigeration system and returned to the compressor. At this time, a mixed liquid of refrigerant, RFC-134a, and refrigerating machine oil is supplied to the mechanical part through the oil supply device 8 for lubrication.

In this way, while using a hermetic compressor, moisture adsorbed on the surface of the refrigeration system piping and moisture retained in the tight gaps between the silicon steel plates of the stator of the motor section 12 gradually cause heat generation and other problems. It precipitates out. A portion of this precipitated water is dissolved in the refrigerant, circulated through the refrigeration system, and dehydrated by a desiccant in the dryer. However, most of it dissolves in refrigerating machine oil, and especially in ester-based refrigerating machine oil, it hydrolyzes, producing acids and harmful substances.

Next, a case where refrigerant RF C-134a is dissolved in refrigerating machine oil will be explained.

The volume resistance value, which is one of the indicators of insulation properties, is shown for each substance.

RFC-134a 109Qcm Glycol-based refrigeration oil 100mCFC-12, 10150m Conventional refrigeration oil 1014Ωm Entel-based refrigeration oil 1Q13Ωm (according to our internal measurement results) In other words, in terms of electrical insulation, the larger the value of volume resistance, the higher the insulation. Glycol-based and ester-based refrigeration oils used for the refrigerant RFC-134a have the property of dissolving RFC-1348, and when a large amount of HFC-134a is dissolved, the electrical insulation property decreases rapidly. If the amount is reduced, it is also desirable to lower the oil level.

The present invention prevents a large amount of water from dissolving in the refrigerating machine oil, removes the water in the refrigerating machine oil, and reduces the amount of refrigerant 134a dissolved in the refrigerating machine oil. That is, when the motor of the hermetic compressor is stopped, the heater energization control device 16 energizes the heater 15 to heat the refrigerating machine oil.

By heating the hermetic compressor when the hermetic compressor is stopped using the pick, heater 15 and energization control device 16,
Evaporates the moisture in the refrigerating machine oil and retains it in the gas phase. When the hermetic compressor starts operating, the moisture in the gas phase is circulated through the system and dehydrated by the desiccant in the dryer.

By removing the moisture in the refrigeration oil, it is possible to prevent the generation of acids and harmful substances within the refrigeration system, which prevents the acid from being supplied to the sliding surfaces of the mechanical part 1, causing corrosive wear and crushing the compressor. In addition, polymerized substances among the generated harmful substances can be prevented from clogging the piping of the refrigeration system and causing cooling failure.

In addition, in order to remove moisture in the refrigerating machine oil, the refrigerating machine oil is heated with the heater 15 while the hermetic compressor is stopped, so that the refrigerating machine oil is always kept at a predetermined temperature or higher.Refrigerant RFC into the refrigerating machine oil
As the amount of -134a dissolved decreases and the oil level decreases, stain stun kneading properties are improved, and no current flows during gouging, eliminating the risk of electrical leakage or electric shock.

Next, a second embodiment will be described with reference to FIGS. 2 and 3.

17.18 is the main winding of the motor section 12 of the hermetic compressor;
Auxiliary winding, 19 is an overload relay, 2o is a starting relay, 21 is a starting capacitor, 22 is a running capacitor, 2
3 is a current switching circuit that allows current to flow only through the auxiliary winding.

Next, its operation will be explained.

The shaft 2 is rotated by the rotational force of the motor section 12, moves the pinuton 5, and compresses the refrigerant in the compression chamber 7 formed by the auxiliary bearing 3, the bearing 4, and the cylinder 6. At this time, the temperature of the hermetic compressor increases due to the heat of compression and the heat generated by the motor section 12. Meanwhile, the compressed refrigerant is cooled in the refrigeration system and returned to the compressor. At this time, a liquid mixture of refrigerant RFC-134a and refrigerating machine oil is supplied to the mechanical part through the oil supply device 8 for lubrication.

In this way, while using a hermetic compressor, moisture adsorbed on the surface of the refrigeration system piping and moisture retained in the tight gaps between the silicon steel plates of the stator of the motor section 12 can be removed due to heat generation, etc. It gradually fades away. A portion of this precipitated water is dissolved in a refrigerant, circulated through the refrigeration system, and dehydrated by a desiccant in the dryer. However, most of it dissolves in refrigerating machine oil, and especially in ester-based refrigerating machine oil, it hydrolyzes, producing acids and harmful substances.

Next, a case where refrigerant RFC-134a is dissolved in refrigerating machine oil will be explained.

Glycol-based and ester-based refrigeration oils used for the refrigerant HFC-134a have the property of dissolving RFC-134a. It is desirable to reduce the amount dissolved and to lower the oil level.

The present invention prevents a large amount of water from dissolving in the refrigerating machine oil, removes the water in the refrigerating machine oil, and reduces the amount of refrigerant RFC-134& dissolved in the refrigerating machine oil. In other words, when the motor of the hermetic compressor is stopped,
Current is passed through the switching circuit 23 only to the auxiliary winding 18, and the generated heat heats the refrigerating machine oil.

By passing current only through the pick and auxiliary windings 18, the refrigerating machine oil is heated, water in the refrigerating machine oil is evaporated, and the water is kept in the gas phase. When the hermetic compressor starts operating, the moisture in the gas phase is circulated through the system and dehydrated by the desiccant in the dryer.

By removing the moisture in the refrigeration oil, it is possible to prevent the generation of acids and harmful substances within the refrigeration system, which prevents the acid from being supplied to the sliding surfaces of the mechanical part 1, causing corrosive wear and crushing the compressor. However, it is possible to prevent the generated m-polymerized substances from clogging the pipes of the refrigeration system and causing poor cooling.

In addition, in order to remove moisture from the refrigerating machine oil, the refrigerating machine oil is heated with an electric current passed through the auxiliary winding 18 while the hermetic compressor is stopped, so that the refrigerating machine oil is always kept at a predetermined temperature or higher. The amount of dissolved refrigerant RFC-134a is reduced, and the oil level is lowered, which improves stain stifling properties and prevents current from flowing through the casing, eliminating the risk of electrical leakage and electric shock.

Furthermore, since the first embodiment does not require the heater 16 and the energization control device, it is economical.

Next, a third embodiment will be described with reference to FIGS. 2 and 3.

24 is a voltage variable device that controls the voltage applied to the hermetic compressor.

Next, its operation will be explained.

The shaft 2 is rotated by the rotational force of the motor section 12, moves the binuton 6, and compresses the refrigerant in the compression chamber 7 formed by the auxiliary bearing 3, the bearing 4, and the cylinder 6. At this time, the temperature of the hermetic compressor increases due to the heat of compression and the heat generated by the motor section 120. Meanwhile, the compressed refrigerant is cooled in the refrigeration system and returned to the compressor. At this time, a liquid mixture of refrigerant RFC-134a and refrigerating machine oil is supplied to the mechanical part through the oil supply device 8 for lubrication.

In this way, while using a hermetic compressor, moisture adsorbed on the surface of the refrigerating system piping and moisture retained in the tight gaps between the silicon steel plates of the stator of the motor section 12 can be removed due to heat generation, etc. It will gradually precipitate. A portion of this precipitated water is dissolved in the refrigerant, circulated through the freezing system, and dehydrated by the desiccant in the dryer. However, most of it dissolves in refrigerating machine oil, and especially in ester-based refrigerating machine oil, it hydrolyzes, producing acids and harmful substances.

Next, a case where refrigerant RFC-134a is dissolved in refrigerating machine oil will be explained.

Glycol-based and ester-based refrigeration oils used for the refrigerant RF C-134a have the property of dissolving RFC-134&; It is desirable to reduce the dissolved amount and lower the oil level.

The present invention prevents a large amount of water from dissolving in the refrigerating machine oil, removes the water in the refrigerating machine oil, and reduces the amount of refrigerant RFC-134a dissolved in the refrigerating machine oil. In other words, when the motor of the hermetic compressor is stopped,
The voltage applied to the hermetic compressor is controlled by the voltage variable device 24, and a voltage lower than the voltage at which the motor section 12 rotates is applied to heat the refrigerating machine oil by the heat generated.

The refrigerating machine oil is heated by controlling the voltage applied to the hermetic compressor by the variable voltage device @24, and the water in the refrigerating machine oil is evaporated and kept in the gas phase. When the hermetic compressor starts operating, moisture in the gas phase circulates through the synutem and is dehydrated by the desiccant in the dryer.

By removing the water in the refrigeration oil, it is possible to prevent the generation of acids and harmful substances within the refrigeration system, and the possibility that the acid will be supplied to the sliding surfaces of the mechanical part 1, causing corrosive wear and crushing the compressor. It is possible to prevent polymers among the generated harmful substances from clogging the piping of the frozen synutem and causing cooling failure.

In addition, in order to remove moisture in the refrigerating machine oil, the voltage is controlled by the voltage variable device 24 while the hermetic compressor is stopped, and the generated heat is used to heat the refrigerating machine oil. Since the amount of refrigerant RF C-134a dissolved in the gas is small, the oil level is lowered, which improves electrical insulation, and no current flows through the puffer, eliminating the risk of electrical leakage or electric shock.

Furthermore, compared to the second embodiment, since the voltage variable device 24 is used, the temperature of the refrigeration oil can be controlled depending on the outside temperature.

Effects of the Invention The present invention comprises a sealed casing in which refrigerant RFC-1348 and Entel-based or Krikol-based refrigeration oil are sealed, a mechanical part housed in the sealed casing, a motor part for driving the mechanical part, and a refrigerating machine in the mechanical part. In a hermetic compressor consisting of an oil supply device for conveying machine oil, a heater closely attached to the hermetic casing is provided, and a control circuit for energizing the heater is provided, and a switching circuit is provided for passing current only to the auxiliary winding. It is equipped with a voltage variable device for the voltage applied to the main and auxiliary windings, and removes moisture before it generates large amounts of acid and harmful substances, preventing electrical leakage, corrosive wear, and poor cooling. In addition, the amount of HFC-134a dissolved in the refrigerating machine oil is reduced and the oil level is lowered, improving electrical insulation and eliminating the risk of electrical leakage or electric shock.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a compressor according to a first embodiment of the present invention, and FIG. 2 is a sectional view of a compressor according to a second embodiment of the present invention. A sectional view of a compressor according to a third embodiment, FIG. 3 is a power supply circuit diagram of a compressor according to a second embodiment of the present invention, and FIG. 4 is a power supply circuit diagram of a compressor according to a third embodiment of the present invention. FIG. 5 is a sectional view of a conventional compressor. 1...Mechanical part, 12...Motor part, 1
5...Heater 16...Electrification control device, 23...Current switching device, 24...
Voltage variable device. Name of agent: Patent attorney Shigetaka Awano and 1 other person 1st
Figure 2 Figure 23-t Jino L#i! %! 24 Voltage variable device mechanical department motor commander heater team

Claims (3)

[Claims] (1) A sealed casing containing a 1,1,1,2-tetrafluoroethane refrigerant and ester-based or glycol-based refrigeration oil, a mechanical part housed in the sealed casing, and a motor that drives the mechanical part. What is claimed is: 1. A hermetic compressor comprising: a refrigerating machine section; an oil supply device for conveying refrigerating machine oil to the mechanical section; and a heater in close contact with the hermetic casing, and further comprising a control device for energizing the heater. (2) The hermetic compressor according to claim (1), characterized in that a switching circuit that allows current to flow only through the auxiliary winding is provided instead of the heater and energization control circuit. (3) The hermetic compressor according to claim (1), characterized in that a voltage variable device for the voltage applied to the main winding and the auxiliary winding is provided in place of the switching circuit.