JP2015025363A - Hermetic compressor and refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hermetic compressor capable of preventing degradation in volumetric efficiency and ensuring high efficiency by inhibiting drawn-in refrigerant gas from receiving heat from a cylinder bore and being heated.SOLUTION: An inner wall surface 142a of a cylinder bore 118 of a cylinder block 111 is formed out of a heat insulation layer 143. By doing so, during operation, the heat insulation layer 143 is hardly heated by refrigerant gas 106 compressed within a compression chamber 117 and having a high temperature, thereby inhibiting a temperature rise of the inner wall surface 142a of the cylinder bore 118. Owing to this, after the refrigerant gas 106 is compressed and discharged, refrigerant gas 106 newly drawn in the compression chamber 117 hardly receives heat from the heat insulation layer 143 formed on the inner wall surface 142a of the cylinder bore 118. Therefore, it is possible to inhibit the temperature rise of the drawn-in refrigerant gas 106, improve volumetric efficiency, and improve efficiency of a hermetic compressor.

Description

  The present invention relates to a hermetic compressor and a refrigeration apparatus such as a domestic refrigerator-freezer and a showcase using the hermetic compressor.

  In recent years, the demand for protection of the global environment has been increasing, and there is a strong demand for higher efficiency in hermetic compressors used in household refrigerator-freezers and other refrigerators.

  Under such circumstances, conventionally, in this type of hermetic compressor, the front end surface of the piston accommodated in the cylinder bore is covered with a heat insulating material to improve the heat insulating property in the compression chamber and to increase the efficiency. (For example, see Patent Document 1).

  FIG. 4 is a longitudinal sectional view in the cylinder bore of the conventional hermetic compressor described in Patent Document 1.

  As shown in FIG. 4, the conventional hermetic compressor has a cylinder bore 18 penetrating the cylinder 11. The piston 12 is accommodated in the cylinder bore 18, and the piston 12 is in contact with the inner wall surface 19 of the cylinder bore 18 and reciprocates. The piston 12 defines a compression chamber 17 in the cylinder bore 18, and a heat insulating material 43 is bonded to the front end surface 13 of the piston 12 on the compression chamber 17 side by an adhesive layer 44, and the front end surface 13 is entirely covered by the heat insulating material 43. Yes.

JP 2005-188405 A

  However, in the conventional configuration, the tip surface 13 of the piston 12 has improved heat insulation, but the inner wall surface 19 of the cylinder bore 18 that is not insulated is heated by the heat of the refrigerant gas compressed in the compression chamber 17 and heated to a high temperature. As a result, the temperature of the inner wall surface 19 of the cylinder bore 18 rises.

  Therefore, after the refrigerant gas is compressed and discharged, the low-temperature refrigerant gas newly sucked into the compression chamber 17 receives heat from the inner wall surface 19 of the cylinder bore 18 and has a problem that the volume efficiency is lowered.

  The present invention solves the above-described conventional problems, and prevents the sucked refrigerant gas from receiving heat from the inner wall surface of the cylinder bore to increase the temperature to prevent a decrease in volumetric efficiency. An object is to provide a compressor.

  In order to solve the above-mentioned conventional problems, the hermetic compressor of the present invention is such that the inner wall surface of the cylinder bore of the cylinder block is formed of a heat insulating layer.

  As a result, the thermal conductivity of the inner wall surface of the cylinder bore of the cylinder block is small due to the presence of the heat insulation layer, and it is difficult to be heated by the refrigerant gas that has been compressed in the compression chamber and becomes hot during operation. Is done.

  Therefore, it is difficult for the low-temperature refrigerant gas newly sucked into the compression chamber after compressing and discharging the refrigerant gas to receive heat from the heat insulating layer formed on the inner wall surface of the cylinder bore of the cylinder block, and the temperature of the sucked refrigerant gas The rise can be suppressed and the volumetric efficiency can be improved.

  The hermetic compressor of the present invention can suppress an increase in the temperature of the sucked refrigerant gas and prevent a decrease in volumetric efficiency, so that the efficiency of the hermetic compressor can be improved.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. The expanded sectional view of the principal part of the hermetic compressor in Embodiment 1 of the present invention. Schematic diagram of a refrigeration apparatus in Embodiment 2 of the present invention Longitudinal sectional view in the cylinder bore of a conventional hermetic compressor

  According to a first aspect of the present invention, an electric element and a compression element driven by the electric element are accommodated in a sealed container. The compression element includes a main shaft and an eccentric shaft, and the main shaft of the crank shaft. A cylinder block having a bearing portion supporting the shaft and a cylinder bore penetrating in a cylindrical shape, a piston reciprocating in the cylinder bore, a connecting means for connecting the eccentric shaft of the crankshaft and the piston, A valve plate is disposed at an end of the cylinder bore and forms a compression chamber with the piston, and an inner wall surface of the cylinder bore is formed of a heat insulating layer.

  As a result, the heat insulating layer provided on the inner wall surface of the cylinder bore of the cylinder block has a low thermal conductivity, so that it is difficult to receive heat from the refrigerant gas that has been compressed in the compression chamber and becomes hot during operation, and the temperature of the inner wall surface of the cylinder bore The rise is suppressed. For this reason, it is difficult for the low-temperature refrigerant gas newly sucked into the compression chamber after compressing and discharging the refrigerant gas to receive heat from the heat insulating layer provided on the inner wall surface of the cylinder bore of the cylinder block, and the temperature of the sucked refrigerant gas increases. Since the volume efficiency can be improved, the efficiency of the hermetic compressor can be improved.

  In the second invention, in particular, in the first invention, the heat insulating layer on the inner wall surface of the cylinder bore is formed by coating the inner wall surface of the cylinder bore with a resin.

  As a result, the heat insulating layer can be easily formed while maintaining the shape of the inner wall of the cylinder bore with high accuracy, and productivity can be improved. Furthermore, since the loss due to leakage or sliding between the cylinder bore and the piston can be suppressed, the efficiency of the hermetic compressor can be further improved.

  In a third aspect of the invention, in particular, in the first or second aspect of the invention, the outer surface around the cylinder bore of the cylinder block is formed of a high thermal radiation layer.

  As a result, the heat of the cylinder block, which has risen due to slight heat transmitted from the inner wall surface of the cylinder bore via the heat insulating layer formed on the inner wall surface of the cylinder bore, is transferred from the high heat radiation layer on the outer surface of the cylinder block to the refrigerant in the sealed container. Since it is easily released to the gas as radiant heat, the temperature rise of the cylinder block and the heat insulating layer can be further suppressed, the volumetric efficiency can be improved, and the efficiency of the hermetic compressor can be further improved.

  In a fourth aspect of the invention, in particular, in the third aspect of the invention, the inner wall surface of the sealed container is formed of a high heat radiation layer.

  Thus, the radiant heat released from the cylinder block to the refrigerant gas in the sealed container can be easily absorbed without being reflected by the high heat radiation layer on the inner wall surface of the sealed container, so that the refrigerant gas in the sealed container, the cylinder block, and The temperature rise of the heat insulation layer can be further suppressed, the volumetric efficiency can be improved, and the efficiency of the hermetic compressor can be further improved.

  In the fifth aspect of the invention, in particular, in the fourth aspect of the invention, the outer wall surface of the sealed container is formed of a high heat radiation layer.

  As a result, the heat absorbed by the inner wall surface of the sealed container can be released to the outside of the sealed container by the high heat radiation layer formed on the outer wall surface, so that the sealed container, the refrigerant gas in the sealed container, the cylinder block, and the heat insulating layer Temperature rise can be further suppressed, volumetric efficiency can be improved, and the efficiency of the hermetic compressor can be further improved.

  In a sixth aspect of the invention, in particular, in any one of the first to fifth aspects of the invention, the electric element is configured to be inverter-driven at a plurality of operating frequencies.

  As a result, heat transfer from the refrigerant gas compressed in the compression chamber to a high temperature to the heat insulation layer formed on the inner wall surface of the cylinder bore is suppressed and sucked even at low speed rotation where the flow rate of the refrigerant gas is slow and heat transfer is easy. Since the heat reception from the heat insulation layer of the refrigerant gas is suppressed, the volumetric efficiency can be further improved, and the efficiency of the hermetic compressor can be improved.

  A seventh invention has a refrigerant circuit in which a hermetic compressor, a radiator, a pressure reducing device, and a heat absorber are connected in an annular shape by piping, and the hermetic compressor is hermetically sealed according to any one of the first to sixth inventions. This is a refrigeration system as a mold compressor.

  Thereby, the power consumption of the refrigeration apparatus can be reduced by mounting the hermetic compressor with improved efficiency, and energy saving can be realized.

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

(Embodiment 1)
FIG. 1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention, and FIG. 2 is an enlarged sectional view of a main part of the hermetic compressor according to Embodiment 1 of the present invention.

  1 and 2, the hermetic compressor according to the first embodiment includes an electric element 102 and a compression element 103 driven by the electric element 102 inside a hermetic container 101 formed by drawing a steel plate. A compressor main body 104 mainly composed of is arranged. The compressor body 104 is elastically supported by a suspension spring 105.

  Furthermore, in the sealed container 101, for example, a refrigerant gas 106 such as a hydrocarbon-based R600a having a low global warming potential is at a pressure that is the same as that of the low-pressure side of the refrigeration apparatus (not shown) and is in a relatively low temperature state. In addition to being sealed, lubricating oil 107 for lubrication is sealed at the bottom of the sealed container 101.

  The sealed container 101 has one end communicating with the space in the sealed container 101 and the other end connected to a suction pipe 108 connected to a refrigeration apparatus (not shown) and a refrigerant gas 106 compressed by the compression element 103. And a discharge pipe 109 leading to an apparatus (not shown).

  The compression element 103 includes a crankshaft 110, a cylinder block 111, a piston 112, a connecting means 113, and the like. The crankshaft 110 includes an eccentric shaft 114, a main shaft 115, and an oil supply mechanism 116. The oil supply mechanism 116 supplies the oil 107 from the lower end of the main shaft 115 immersed in the oil 107 to the upper end of the eccentric shaft 114, and includes a spiral groove 116a formed on the surface of the main shaft 115.

  The cylinder block 111 is integrally formed with a cylinder bore 118 that forms a compression chamber 117, and includes a bearing portion 119 that rotatably supports the main shaft 115.

  In addition, a valve plate 122 having a suction hole 120 and a discharge hole 121, a suction valve 123 for opening and closing the suction hole 120, and a cylinder for closing the valve plate 122 are formed on the opening end surface 118 a on the side opposite to the crankshaft 110 of the cylinder bore 118. The head 124 is fixed together by a head bolt (not shown).

  The cylinder head 124 has a discharge space 126 from which the refrigerant gas 106 is discharged, and the discharge space 126 communicates directly with the discharge pipe 109 via a discharge pipe 127.

  The suction muffler 128 is molded mainly from a synthetic resin such as polybutylene terephthalate (PBT) to which glass fiber is added, and includes a tail pipe 129 that guides the refrigerant gas 106 into the suction muffler 128 and the refrigerant gas 106 in the suction muffler 128. A communication pipe 130 that leads into the compression chamber 117 and a muffler main body 132 that forms a silencing space 131 are provided.

  The inner wall surface 142a of the cylinder bore 118 forming the compression chamber 117 is finished with high accuracy by machining, and the surface is coated with a fluororesin to form a heat insulating layer 143.

  A high heat radiation layer 144 is formed on the outer surface 142b of the cylinder block 111 around the cylinder bore 118 by ceramic coating.

  Further, a high heat radiation layer 145 and a high heat radiation layer 146 are formed on the inner wall surface 101a and the outer wall surface 101b of the sealed container 101 by ceramic coating, respectively.

  The electric element 102 is fixed below the cylinder block 111 with bolts (not shown), and is arranged coaxially with the stator 137 inside the stator 137 and fixed to the main shaft 115 by shrink fitting or the like. And the rotor 138 formed.

  The electric element 102 is connected to an external inverter drive circuit (not shown), and is inverter-driven at a plurality of operating frequencies.

  The operation and action of the hermetic compressor configured as described above will be described below.

  The hermetic compressor has a suction pipe 108 and a discharge pipe 109 connected to a refrigeration apparatus (not shown) to form a refrigeration cycle.

  In this configuration, when the electric element 102 is energized, a current flows through the stator 137, a magnetic field is generated, and the rotor 138 fixed to the main shaft 115 rotates. The rotation causes the crankshaft 110 to rotate, and the piston 112 reciprocates in the cylinder bore 118 via the connecting means 113 that is rotatably attached to the eccentric shaft 114.

  As the piston 112 reciprocates, the refrigerant gas 106 is sucked, compressed, and discharged in the compression chamber 117.

  Next, the steps of suction, compression, and discharge of the hermetic compressor will be described.

  First, when the piston 112 moves in the direction in which the volume of the compression chamber 117 increases, the refrigerant gas 106 in the compression chamber 117 expands. When the pressure in the compression chamber 117 falls below the suction pressure, the suction valve 123 starts to open due to the difference between the pressure in the compression chamber 117 and the pressure in the suction muffler 128.

  Along with this operation, the low-temperature refrigerant gas 106 returned from the refrigeration cycle is once released into the sealed container 101 from the suction pipe 108, and then sucked from the suction port (not shown) of the suction muffler 128. Then, the sound is introduced into the silencing space 131. The introduced refrigerant gas 106 flows into the compression chamber 117 through the communication pipe 130.

  Thereafter, when the operation of the piston 112 changes from the bottom dead center in a direction in which the volume in the compression chamber 117 decreases, the refrigerant gas 106 in the compression chamber 117 is compressed, and the pressure in the compression chamber 117 increases. When the pressure in the compression chamber 117 exceeds the pressure in the suction muffler 128, the suction valve 123 is closed.

  Next, when the pressure in the compression chamber 117 exceeds the pressure in the discharge space 126, the discharge valve (not shown) starts to open due to the difference between the pressure in the compression chamber 117 and the pressure in the discharge space 126.

  With this operation, the compressed refrigerant gas 106 is discharged from the discharge hole 121 to the discharge space 126 until the piston 112 reaches top dead center. Then, the refrigerant gas 106 discharged into the discharge space 126 sequentially passes through the discharge pipe 127 and the discharge pipe 109 and is sent out to a refrigeration apparatus (not shown).

  Thereafter, when the operation of the piston 112 is changed from the top dead center to the direction in which the volume in the compression chamber 117 increases again, the refrigerant gas 106 in the compression chamber 117 expands, the pressure in the compression chamber 117 decreases, and the compression chamber When the pressure in 117 falls below the pressure in the discharge space 126, the discharge valve (not shown) is closed.

  The suction, compression, and discharge processes as described above are repeated for each rotation of the crankshaft 110, and the refrigerant gas 106 circulates in the refrigeration apparatus (not shown).

  Here, when the refrigerant gas 106 in the compression chamber 117 is compressed, the temperature of the refrigerant gas 106 rises and becomes high.

  In a general configuration, the inner wall surface 142a of the cylinder bore 118 is heated by the refrigerant gas 106 having a high temperature and the temperature rises, and the low-temperature refrigerant gas 106 newly sucked into the compression chamber 117 is discharged from the inner wall surface 142a of the cylinder bore 118. It receives heat and the volumetric efficiency decreases.

  However, in the present embodiment, the heat insulating layer 143 is formed by coating the inner wall surface 142a of the cylinder bore 118 with the fluororesin, so that the heat insulating layer 143 having a low thermal conductivity is received by the refrigerant gas 106 having a high temperature. Is small and temperature rise is suppressed. Therefore, the temperature increase of the sucked refrigerant gas 106 is suppressed and the volumetric efficiency is improved, and the efficiency of the hermetic compressor can be improved.

In this embodiment, it is conceivable that a slight amount of heat is transmitted from the inner wall surface 142a of the cylinder bore 118 via the heat insulating layer 143 and the surface of the cylinder block 111 rises in temperature. Since the high heat radiation layer 144 is formed by ceramic coating on the outer surface 142b around the cylinder bore 118, the heat of the cylinder block 111 is easily released as radiation heat to the refrigerant gas 106 in the sealed container 101.

  Further, since the high heat radiation layer 145 and the high heat radiation layer 146 are formed on the inner wall surface 101a and the outer wall surface 101b of the sealed container 101 by ceramic coating, respectively, the heat of the refrigerant gas 106 in the sealed container 101 is transferred to the high heat radiation layer 145. Can be absorbed and released from the high thermal radiation layer 146 to the outside of the sealed container 101.

  As a result, the temperature rise of the heat insulation layer 143 formed on the inner wall surface 142a of the cylinder bore 118 can be further suppressed, and the amount of heat received from the heat insulation layer 143 of the low-temperature refrigerant gas 106 newly sucked into the compression chamber 117 is reduced. It becomes even smaller. As a result, the temperature rise of the sucked refrigerant gas 106 is further suppressed and the volumetric efficiency is improved, and the efficiency of the hermetic compressor can be improved.

  As the resin used for coating the inner wall surface 142a of the cylinder bore 118, a resin other than a fluororesin may be used as long as it is durable to oil and refrigerant and has high wear resistance. In addition, if the coating range is provided only in the portion of the inner wall surface 142a of the cylinder bore 118 where the compression chamber 117 is formed, a heat insulation effect can be obtained. However, by coating the entire inner wall surface 142a, productivity can be improved. The effect that the coating is difficult to peel is also obtained.

  Further, the high heat radiation layer 144 formed on the outer surface 142b around the cylinder bore 118 of the cylinder block 111 and the high heat radiation layer 145 formed on the inner wall surface 101a of the sealed container 101 have durability against oil or refrigerant. A high heat radiation material other than ceramic may be coated. In addition to the coating, the outer surface 142b of the cylinder block 111 and the surface of the inner wall surface 101a of the sealed container 101 may be oxidized to form a metal oxide film, and this metal oxide film plays the role of a high heat radiation layer. The effect is obtained.

  Further, by making the outer surface 142b of the cylinder block 111 and the inner wall surface 101a of the sealed container 101 rough, the heat dissipation and heat absorption effect can be enhanced. The range of the high heat radiation layer may be provided on the entire outer surface 142b of the cylinder block 111 and the entire inner wall surface 101a of the sealed container 101, but at least around the cylinder bore 118 where the temperature increases on the outer surface 142b of the cylinder block 111. It is effective to provide it on the inner wall surface 101a of the sealed container 101 at a position corresponding thereto.

  Further, as the high heat radiation layer 146 formed on the outer wall surface 101b of the hermetic container 101, there is no need for durability against oil or refrigerant, and therefore any high heat radiation material that can be coated can be applied.

  In addition to the coating, the same effect can be obtained by oxidizing the surface of the outer wall surface 101b to form a metal oxide film. Further, the heat dissipation and heat absorption effect can be enhanced by making the outer wall surface 101b rough. As the range of the high heat radiation layer, the heat radiation effect can be enhanced by providing the entire surface of the outer wall surface 101b of the sealed container 101. However, when there is another heat source in the surrounding area, the high heat radiation layer is provided in the vicinity of the heat source so as not to absorb the heat. It is preferable not to provide the layer 146.

Further, when the hermetic compressor of the present embodiment is rotated at a low speed by an inverter drive, heat reception from the heat insulating layer 143 formed on the inner wall surface 142a of the cylinder bore 118 of the low-temperature intake refrigerant gas 106 is suppressed. For this reason, even if the refrigerant gas 106 is taken for a long time after being sucked into the compression chamber 117 and is discharged, the temperature rise of the sucked refrigerant gas 106 can be suppressed even if it is in contact with the heat insulating layer 143 for a long time and easily receives heat. The efficiency will be improved, and the efficiency of the hermetic compressor can be improved.

(Embodiment 2)
FIG. 3 is a schematic diagram showing the configuration of the refrigeration apparatus in Embodiment 2 of the present invention. Here, an outline of the basic configuration of the refrigeration apparatus will be described assuming that the hermetic compressor described in Embodiment 1 is mounted on the refrigerant circuit.

  In FIG. 3, the refrigeration apparatus 200 divides the inside of the main body 201 into an article storage space 202 and a machine room 203, a heat insulating box having an opening on one side, a main body 201 having a door structure that opens and closes the opening. A partition wall 204 and a refrigerant circuit 205 for cooling the inside of the storage space 202 are provided.

  The refrigerant circuit 205 has a configuration in which the hermetic compressor 206, the radiator 207, the decompressor 208, and the heat absorber 209 described in Embodiment 1 are connected in a ring shape.

  And the heat absorber 209 is arrange | positioned in the storage space 202 which comprised the air blower (not shown). The cooling heat of the heat absorber 209 is agitated so as to circulate in the storage space 202 by a blower, as indicated by a broken arrow.

  By mounting the hermetic compressor in the first embodiment of the present invention on the refrigeration apparatus described above, the volumetric efficiency is improved and the refrigerant circuit can be operated with the hermetic compressor with improved efficiency. The power consumption of the apparatus can be reduced and energy saving can be realized.

  As described above, the hermetic compressor and the refrigeration apparatus according to the present invention can suppress the temperature rise of the suction gas, increase the volumetric efficiency, and improve the efficiency of the hermetic compressor. The present invention is not limited to home use such as a conditioner, and can be widely applied to refrigeration apparatuses such as commercial showcases and vending machines.

DESCRIPTION OF SYMBOLS 101 Sealed container 101a Inner wall surface 101b Outer wall surface 102 Electric element 103 Compression element 110 Crankshaft 111 Cylinder block 112 Piston 113 Connection means 114 Eccentric shaft 115 Main shaft 117 Compression chamber 118 Cylinder bore 119 Bearing part 122 Valve plate 142a Inner wall surface 142b Outer surface 143 Thermal insulation Layer 144, 145, 146 High heat radiation layer 200 Refrigeration device 205 Refrigerant circuit 206 Sealed compressor 207 Radiator 208 Decompression device 209 Heat absorber

Claims (7)

An electric element and a compression element driven by the electric element are accommodated in an airtight container, and the compression element includes a crankshaft composed of a main shaft and an eccentric shaft, and a bearing that supports the main shaft of the crankshaft. A cylinder block having a portion and a cylindrical cylinder bore, a piston reciprocating in the cylinder bore, a connecting means for connecting the eccentric shaft of the crankshaft and the piston, and an end of the cylinder bore A hermetic compressor including a valve plate that is disposed and forms a compression chamber with the piston, and an inner wall surface of the cylinder bore is formed of a heat insulating layer. The hermetic compressor according to claim 1, wherein the heat insulating layer provided on the inner wall surface of the cylinder bore is formed by coating the inner wall surface of the cylinder bore with a resin. The hermetic compressor according to claim 1 or 2, wherein an outer surface of the cylinder block around the cylinder bore is formed of a high heat radiation layer. The hermetic compressor according to claim 3, wherein an inner wall surface of the hermetic container is formed of a high heat radiation layer. The hermetic compressor according to claim 4, wherein an outer wall surface of the hermetic container is formed of a high heat radiation layer. The hermetic compressor according to claim 1, wherein the electric element is inverter-driven at a plurality of operating frequencies. A hermetic compressor according to any one of claims 1 to 6, further comprising: a refrigerant circuit in which a hermetic compressor, a radiator, a decompressor, and a heat absorber are connected in a ring shape by piping. Refrigeration equipment.