JP2006037826A - Refrigerant compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable refrigerant compressor using low viscosity lubricant. <P>SOLUTION: Reliability is improved since abnormal wear due to breakage of oil film created by evaporation of lubricant at a sliding part can be prevented by using ion liquid 103 of which evaporation temperature is 400°C-1000°C as lubricant stored in a hermetic vessel 101 and compression failure caused by deposition of PET (polyethylene terephthalate) or the like on a surface of a delivery lead 120 or the like due to evaporation of lubricant can be prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a refrigerant compressor used for a refrigerator, an air conditioner and the like.

  Conventionally, as this type of refrigerant compressor, a highly efficient refrigerant compressor that reduces the use of fossil fuels has been developed from the viewpoint of protecting the global environment. Dynamic loss is reduced (see, for example, Patent Document 1).

  The conventional rotary compressor will be described below with reference to the drawings.

  FIG. 3 is a cross-sectional view of a prior art hermetic electric refrigerant compressor. FIG. 4 is an enlarged view of part B of FIG. 3 of the prior art. The airtight container 1 stores lubricating oil 2 made of VG10-20 mineral oil at the bottom, and houses a stator 3 and an electric element 5 made of a rotor 4 and a reciprocating compression mechanism 6 driven thereby. ing. Moreover, R600a is used as a refrigerant.

  Next, details of the compression mechanism 6 will be described below.

  The crankshaft 7 includes a main shaft portion 8 in which the rotor 4 is press-fitted and fixed, and an eccentric portion 9 formed eccentric to the main shaft portion 8, and is provided with an oil supply pump 10. The cylinder block 11 has a compression chamber 13 composed of a substantially cylindrical bore 12 and a bearing 14 that supports the main shaft portion 8.

  The piston 15 loosely fitted in the bore 12 is connected to the eccentric portion 9 via a piston pin 16 by a connecting rod 17 that is a connecting means.

  The valve plate 20 is disposed so as to seal the end face of the bore 12, and a suction hole 24 and a discharge hole 25 are formed. A suction lead 18 made of a plate-like spring material is sandwiched between the end face of the bore 12 and the valve plate 20 to open and close the suction hole. A discharge lead 19 made of a plate-like spring material is disposed on the side opposite to the bore 12 of the valve plate 20 and opens and closes the discharge hole. The head 21 is fixed to the side of the valve plate 20 opposite to the bore 12 and forms a high-pressure chamber 26 that houses the discharge lead 19.

  The suction tube 22 is fixed to the sealed container 1 and connected to the low pressure side (not shown) of the refrigeration cycle, and guides a refrigerant gas (not shown) into the sealed container 1. The suction muffler 23 is sandwiched between the valve plate 20 and the head 21.

  The main shaft portion 8 and the bearing 14 of the crankshaft 7, the piston 15 and the bore 12, the piston pin 16 and the connecting rod 17, and the eccentric portion 9 and the connecting rod 17 of the crankshaft 7 form a sliding portion.

  Next, a series of operations in the above configuration will be described.

  Electric power supplied from a commercial power source (not shown) is supplied to the electric element 5 to rotate the rotor 4 of the electric element 5. The rotor 4 rotates the crankshaft 7, and the eccentric movement of the eccentric portion 9 drives the piston 15 from the connecting rod 17 of the connecting means via the piston pin 16, whereby the piston 15 reciprocates in the bore 12.

  The refrigerant gas introduced into the sealed container 1 through the suction tube 22 opens the suction lead 18 through the suction muffler 23 and is sucked into the compression chamber 13 through the suction hole 24. The refrigerant gas sucked into the compression chamber 13 is continuously compressed, opens the discharge lead 19, is discharged from the discharge hole 25 to the high pressure chamber 26, and is sent out to the high pressure side (not shown) of the refrigeration cycle.

As the crankshaft 7 rotates, the lubricating oil 2 is supplied to each sliding portion from the oil pump 10, and the sliding portion is lubricated to reduce the coefficient of friction and to seal between the piston 15 and the bore 12. Control.
JP 2000-2977753 A

  However, in the conventional lubricating oil 2 made of mineral oil or the like, if the viscosity is lowered for the purpose of improving efficiency, the boiling point is lowered, and the lubricating oil is likely to evaporate due to sliding heat generation in the sliding portion. As a result, the oil film is broken and the friction coefficient is increased, which may cause a decrease in efficiency and abnormal wear.

  The refrigerant gas compressed in the compression chamber 13 opens the discharge lead 19 and is discharged from the discharge hole 25 to the high pressure chamber 26. At this time, the temperature of the refrigerant gas in the high pressure chamber is about 160 ° C. at the maximum. On the other hand, PET (polyethylene terephthalate) or the like used as an insulating material for the stator is extracted from the lubricating oil 2, and the lubricating oil 2 is circulated by being transported by the refrigerant gas and adheres to the discharge lead 19. Here, when the viscosity of the lubricating oil 2 made of conventional mineral oil or the like is lowered, the lubricating oil is likely to evaporate at the discharge lead that becomes high temperature, and PET (polyethylene terephthalate) or the like in the lubricating oil is deposited on the surface of the discharge lead 19. . This precipitate carbonizes at high temperature and accumulates as oil sludge, which impairs the sealability of the discharge lead 19 and causes a compression failure.

  An object of the present invention is to solve the conventional problem and to provide a refrigerant compressor having high reliability while using a low viscosity lubricant.

  The refrigerant compressor according to the present invention can prevent the oil film from being broken by evaporation of the lubricant at the sliding portion by using the ionic liquid as the lubricant stored in the sealed container, and can also prevent the lubricant from being discharged by a discharge lead or the like. It is possible to prevent PET (polyethylene terephthalate) or the like extracted into the lubricant by evaporating from depositing on the surface of the discharge lead or the like.

  The refrigerant compressor of the present invention provides a highly reliable refrigerant compressor while using a low-viscosity lubricant by preventing wear of sliding members due to evaporation of the lubricant and generation of sludge such as PET (polyethylene terephthalate). can do.

  The invention according to claim 1 stores a lubricant in an airtight container and accommodates a compression mechanism for compressing a refrigerant gas, and uses the lubricant as an ionic liquid. Since it is 1000 ° C., it can prevent the oil film from being broken due to the evaporation of the lubricant at the sliding part, and the lubricant is evaporated at the discharge lead, etc., and PET (polyethylene terephthalate) contained in the lubricant is discharged. Refrigerant with high reliability while using a low-viscosity lubricant by preventing precipitation on the surface of leads, etc. and preventing wear of sliding members due to evaporation of lubricant and generation of sludge such as PET (polyethylene terephthalate) A compressor can be provided.

  According to the second aspect of the present invention, the ionic liquid according to the first aspect of the present invention is converted to TFSI ((CF3SO2) 2N-) and pyridinium cation (RP) or tetrafluoroborate anion (BF4-) and imidazolium cation. (RI) or TFSI ((CF3SO2) 2N-) and methyl acid 2- (diethylamino) ethyl cation (DEMA) or tetrafluoroborate anion (BF4-) and methyl acid 2- (diethylamino) ethyl cation (DEMA) Thus, since the evaporation temperature becomes 400 ° C. to 1000 ° C., the evaporation of the lubricant at the sliding portion and the discharge lead can be prevented, and the reliability can be increased.

  The invention according to claim 3 is obtained by adding a phosphorus-based extreme pressure additive to the ionic liquid according to claim 1 or claim 2, and the oil film thickness is reduced by using a low-viscosity ionic liquid. Even when the thickness is reduced, the wear resistance is improved by the extreme pressure effect of the phosphorus-based extreme pressure additive, so that the reliability can be further increased.

  The invention according to claim 4 is the refrigerant according to any one of claims 1 to 3 which is any one of R600a, R290, or a mixture thereof, and reduces the viscosity of the lubricant. Even in the combination with an easy-to-use refrigerant, holding the lubricant in the sliding portion prevents abnormal wear of the sliding portion, and can increase reliability while using a low-viscosity lubricant.

  The invention according to claim 5 is the refrigerant according to any one of claims 1 to 3 in the form of an HFC refrigerant or a mixture thereof, and also relates to a combination with a refrigerant having poor lubricity. First, by holding the lubricant in the sliding portion, the occurrence of abnormal wear of the sliding portion is prevented, and the reliability can be increased while using the low viscosity lubricant.

  The invention described in claim 6 is the refrigerant according to any one of claims 1 to 3 which is a CO2 refrigerant, and in combination with a refrigerant whose condensation / evaporation pressure becomes high, By holding the lubricant in the sliding portion, occurrence of abnormal wear of the sliding portion can be prevented, and reliability can be increased while using a low viscosity lubricant.

  According to a seventh aspect of the invention, the compression mechanism of the invention according to any one of the first to sixth aspects is a reciprocating compression mechanism, and the lubricant in the discharge lead even in a state where the amount of lubricant circulation is small By preventing the evaporation of the oil, the performance is prevented from being lowered and the lubricant is retained in the sliding part, thereby preventing the abnormal wear of the sliding part. The use of a low-viscosity lubricant is highly reliable. can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
1 is a cross-sectional view of a refrigerant compressor according to Embodiment 1 of the present invention. FIG. 2 is an enlarged view of a portion A in FIG. 1 of the same embodiment.

  In FIG. 1, a sealed container 101 is filled with a refrigerant gas 102 made of R600a, and components at the bottom are TFSI ((CF 3 SO 2) 2 N—) and 2- (diethylamino) ethyl cation (DEMA) methyl acid. The ionic liquid 103 is stored, and an electric element 106 including a stator 104 and a rotor 105 and a reciprocating compression mechanism 107 driven by the electric element 106 are accommodated.

  Next, details of the compression mechanism 107 will be described below.

  The crankshaft 108 is composed of a main shaft portion 109 in which the rotor 105 is press-fitted and fixed, and an eccentric portion 110 formed eccentric to the main shaft portion 109, and an oil supply pump 111 communicating with the ionic liquid 103 is provided at the lower end. The cylinder block 112 made of cast iron forms a substantially cylindrical bore 113 and a bearing portion 114 that supports the main shaft portion 109.

  The piston 115 loosely fitted in the bore 113 is made of an iron-based material, forms a compression chamber 116 together with the bore 113, and is connected to the eccentric portion 110 via a piston pin 117 by a connecting rod 118 as connecting means. The end surface of the bore 113 is sealed with a suction lead 119, a discharge lead 120, and a valve plate 121.

  The valve plate 121 is disposed so as to seal the end surface of the bore 113, and a suction hole 122 and a discharge hole 123 are formed. A suction lead 119 made of a plate-like spring material is sandwiched between the end face of the bore 113 and the valve plate 121 to open and close the suction hole. A discharge lead 120 made of a plate-shaped spring material is disposed on the side opposite to the bore 113 of the valve plate 121 and opens and closes the discharge hole. The head 124 is fixed to the side opposite to the bore 113 of the valve plate 121 and forms a high-pressure chamber 125 that houses the discharge lead 120.

  The suction tube 126 is fixed to the sealed container 101 and connected to the low pressure side (not shown) of the refrigeration cycle, and guides a refrigerant gas (not shown) into the sealed container 101. A suction muffler 127 having a sound deadening space is sandwiched between the valve plate 121 and the head 124 and communicates with the sealed container 101 and the suction hole 122.

  The main shaft portion 109 and the bearing portion 114, the piston 115 and the bore 113, the piston pin 117 and the connecting rod 118, and the eccentric portion 110 and the connecting rod 118 form a sliding portion.

  The operation of the refrigerant compressor configured as described above will be described below.

  Electric power supplied from a commercial power source (not shown) is supplied to the electric element 106 to rotate the rotor 105 of the electric element 106. The rotor 105 rotates the crankshaft 108, and the eccentric movement of the eccentric portion 110 drives the piston 115 from the connecting rod 118 of the connecting means via the piston pin 117, so that the piston 115 reciprocates in the bore 113.

  The refrigerant gas guided into the sealed container 101 through the suction tube 126 opens the suction lead 119 through the suction muffler 127 and is sucked into the compression chamber 13 through the suction hole 122. The refrigerant gas sucked into the compression chamber 116 is continuously compressed, opens the discharge lead 120, is discharged from the discharge hole 123 to the high pressure chamber 125, and is sent out to the high pressure side (not shown) of the refrigeration cycle.

  With the rotation of the crankshaft 108, the ionic liquid 103 is moved from the oil supply pump 111 to the main shaft portion 109 and the bearing portion 114, the piston 115 and the bore 113, the piston pin 117 and the connecting rod 118, and the eccentric portion 110 and the connecting rod 118 which are mutually formed. The moving part is lubricated and lubricated, and the seal between the piston 115 and the bore 113 is controlled.

  When the refrigerant gas sucked into the compression chamber 116 is compressed, the temperature of the refrigerant gas 102 in the high pressure chamber of the head 124 reaches a maximum of about 160 ° C., and the ionic liquid 103 contained in the refrigerant gas also rises to about 160 ° C.

  However, since the ionic liquid 103 is an ionic bond having an asymmetric structure, the intermolecular bond is formed by an ionic bond having a high binding energy. Therefore, the evaporation temperature of the ionic liquid 103 is 400 ° C. to 1000 ° C., and the evaporation does not occur even when the temperature of the ionic liquid 103 reaches about 160 ° C. or higher. Even if an organic material such as PET (polyethylene terephthalate) is mixed in the ionic liquid 103, it can be prevented from precipitating on the surface of the discharge lead 120, and the deposit can suppress the compression failure due to the inhibition of the sealing property of the discharge lead 120, etc. Can improve reliability.

  The temperature of the ionic liquid 103 supplied between the sliding portions from the oil supply pump 111 rises due to the sliding heat generation of each sliding portion. Evaporation of the ionic liquid 103 does not occur. As a result, although the refrigerant is R600a and easily dissolves in the ionic liquid 103 and easily reduces the viscosity, the oil film is not easily broken, so that an increase in the coefficient of friction due to metal contact can be prevented, and a decrease in efficiency can be prevented. it can.

  Further, the effect of preventing the oil film from being broken is effective for all sliding part materials. That is, it goes without saying that the same effect can be obtained not only in the combination of iron-based materials but also in the combination of aluminum-based materials, other surface treatments such as nitriding, and coating materials such as ceramics. .

  Further, in the sliding portion formed by the piston 115 and the bore 113, and the piston pin 117 and the connecting rod 118, the mutual sliding speed becomes 0 m / s twice per compression process. At this time, the generated pressure of the ionic liquid 103 becomes zero, and a state where solid contact is likely to occur occurs. By preventing wearing, wear resistance can be improved and reliability can be enhanced.

  In addition, the substance mixed in the ionic liquid 103 this time is an organic material of PET (polyethylene terephthalate) used as an insulating material of the stator 104. However, an LCP (liquid crystal polymer compound) used in the stator 104 or the like is used. Regarding other organic materials and organic materials used for other components such as PBT (polybutylene terephthalate) and PPS (polyphenylene sulfide) used for the suction muffler 127, the temperature of the ionic liquid 103 is 150 ° C. or higher. Since evaporation does not occur even at high temperatures, the same effect can be obtained regardless of the substance to be extracted.

  Also, this time, the combination of R600a and mineral oil has been described as an example, but the ionic liquid 103 is also used in the case where the refrigerant used is R290, which is the same hydrocarbon refrigerant, or in the HFC refrigerant having poor lubricity. Since the evaporation does not occur even when the temperature becomes 150 ° C. or higher, the same effect can be obtained. Furthermore, the effect is particularly high in the case of a CO2 refrigerant that has a high condensation / evaporation pressure and tends to be high in temperature.

  Further, in the present embodiment, the reciprocating refrigerant compressor has been described as an example, but the same effect can be obtained in other compressors having a sliding portion and a discharge valve such as a rotary type, a scroll type, and a vibration type. It goes without saying that it is obtained.

  In this embodiment, the ionic liquid 103 is TFSI ((CF3SO2) 2N-) and 2- (diethylamino) ethyl cation (DEMA) methyl acid, but the ionic liquid 103 is TFSI ((CF3SO2) 2N-). Pyridinium cation (RP) or tetrafluoroborate anion (BF4-) and imidazolium cation (RI) or tetrafluoroborate anion (BF4-) and methyl acid 2- (diethylamino) ethyl cation (DEMA) Since each ionic liquid has an ionic bond with high binding energy, the same effect can be obtained.

  As described above, the refrigerant compressor according to the present invention can provide a highly reliable compressor using a low-viscosity lubricant, and thus can be widely applied to devices using a refrigeration cycle.

Sectional drawing of the refrigerant compressor in Embodiment 1 of this invention. Enlarged view of part A in FIG. 1 of the same embodiment Sectional view of a conventional refrigerant compressor Part B enlarged view of FIG.

Explanation of symbols

101 Sealed container 102 Refrigerant gas 103 Ionic liquid 107 Compression mechanism

Claims (7)

  A refrigerant compressor that stores a lubricant in an airtight container and accommodates a compression mechanism that compresses refrigerant gas, and uses the lubricant as an ionic liquid.   The ionic liquid is TFSI ((CF3SO2) 2N-) and pyridinium cation (RP) or tetrafluoroborate anion (BF4-) and imidazolium cation (RI) or TFSI ((CF3SO2) 2N-) and methyl acid 2- The refrigerant compressor according to claim 1, wherein (diethylamino) ethyl cation (DEMA) or tetrafluoroborate anion (BF4-) and methyl acid 2- (diethylamino) ethyl cation (DEMA) are used.   The refrigerant compressor according to claim 1 or 2, wherein an ionic liquid to which a phosphorus extreme pressure additive is added is used.   The refrigerant compressor according to any one of claims 1 to 3, wherein the refrigerant is any one of R600a and R290, or a mixture thereof.   The refrigerant compressor according to any one of claims 1 to 3, wherein the refrigerant is an HFC-type refrigerant or a mixture thereof.   The refrigerant compressor according to any one of claims 1 to 3, wherein the refrigerant is CO2.   The refrigerant compressor according to any one of claims 1 to 6, wherein the compression mechanism is a reciprocating compression mechanism.

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