JP2020190197A - Hermetic type compressor and refrigerating device using the same - Google Patents

Abstract

To provide a hermetic type compressor having high refrigerating capacity and efficiency while keeping reliability, and a refrigerating device using the same.SOLUTION: An outer peripheral surface of a piston 136 comprises a cylindrical seal part 137 forming a sliding surface, and a sliding part 140 located behind the seal part 137, having the same radius as that of the seal part 137, and supporting lateral pressure on the piston 136. The sliding part 140 comprises a plurality of dimple-like concave parts 142. Thereby, because a sliding area is decreased by the concave parts 142 provided in the sliding part other than the seal part 137 of the piston, a sliding loss is reduced, the efficiency of a hermetic type compressor is improved, and the refrigerating capacity of a refrigerating device can be improved.SELECTED DRAWING: Figure 3

Description

The present invention relates to a closed compressor with reduced sliding loss of a piston and a refrigerating device using the same.

In recent years, due to the demand for global environmental protection, the movement toward energy saving of household refrigeration equipment has been accelerated, and there is a strong demand for the efficiency of the sealed compressor used for this purpose.

Under such circumstances, the conventional sealed compressor for a refrigerating device forms a step drop on a part of the side surface of the piston that slides in the compression chamber to reduce the sliding area and reduce the sliding loss. The efficiency is improved (see, for example, Patent Document 1).

FIG. 8 is a vertical sectional view of the conventional closed compressor described in Patent Document 1, FIG. 9 is an external view of a piston used in the conventional closed compressor, and FIG. 10 is a cylinder of the conventional closed compressor. It is sectional drawing of the main part of the periphery.

In FIGS. 8 to 10, the lubricating oil 4 is stored in the bottom of the closed container 2, and the compressor main body 6 is elastically supported by the suspension spring 8 with respect to the closed container 2.

The compressor main body 6 is composed of an electric element 10 and a compression element 12 arranged above the electric element 10.

The electric element 10 is composed of a stator 14 and a rotor 16. The shaft 18 of the compression element 12 includes a spindle portion 20 and an eccentric shaft portion 22 extending above the spindle portion 20, and the spindle portion 20 is rotatably supported by the main bearing 26 of the cylinder block 24. At the same time, the rotor 16 is fitted and fixed. Further, the shaft 18 is provided with a lubrication mechanism 30 that supplies the lubricating oil 4 at the bottom of the closed container 2 to the upper end of the eccentric shaft portion 22 via a spiral groove 28 or the like on the outer surface of the spindle portion 20. Further, the cylinder block 24 includes a cylindrical cylinder 34, and the piston 36 is reciprocally inserted and is connected to the eccentric shaft portion 22 by a connecting means 23.

The outer peripheral surface of the piston 36 is provided with a seal portion 37, a sliding portion 40, and a step drop 39 in this order from the cylinder head 50 side. The seal portion 37 is a sliding surface formed in a cylindrical shape so as to have a small clearance with respect to the inner diameter surface of the cylinder 34, and the sliding portion 40 has the same radius as the seal portion 37 and is behind the seal portion 37. It is a sliding surface continuously provided on the side, and the step drop 39 is a cutout portion provided so that the radius is smaller than that of the sliding portion 40.

In the conventional sealed compressor configured as described above, when the electric element 10 is energized, the shaft 18 also rotates with the rotation of the rotor 16, and the compression element 12 performs a predetermined compression operation.

When the piston 36 moves from the bottom dead center to the top dead center, it moves smoothly in the cylinder 34 by being guided by the sliding portion 40.

Here, since the piston 36 is provided with the step drop 39, the sliding area can be reduced, the sliding resistance between the piston 36 and the cylinder 34 can be reduced, and the sliding loss can be reduced.

Japanese Patent Publication No. 2004-501320

However, in the above-mentioned conventional configuration, in order to further reduce the sliding loss, the boundary edge 41 between the step drop 39 and the sliding portion 40 is located on the center side of the piston 36 with respect to the vertical direction of the compressor in FIG. When the area of the step drop 39 is expanded, the width of the sliding portion 40 formed on the side surface of the piston 36 becomes narrower, which causes the following problems, and further reduction of the sliding loss can be achieved. It was difficult.

That is, in the compressor, the piston 36 receives the compressive load of the refrigerant gas in the compression stroke from the bottom dead center to the top dead center, and the shaft 18 is strongly pushed in the opposite direction of the piston 36 via the connecting means 23. 18 bends. As a result, a force that greatly tilts the piston 36 in the vertical direction acts. The force that greatly tilts the piston 36 in the vertical direction is mainly received by the sliding portion 40, but the boundary edge 41 is moved toward the center of the piston 36 with respect to the vertical direction of the compressor to narrow the width of the sliding portion 40. Then, the inclination of the piston 36 becomes large, and the gap between the seal portion 37 of the piston 36 and the cylinder 34 expands. As a result, the amount of refrigerant gas leaking from the top dead center side to the bottom dead center side of the piston 36 increases through the gap between the seal portion 37 of the piston 36 and the cylinder 34, and the refrigerating capacity decreases. Further, as the inclination angle increases, the surface pressure near the boundary edge 41 of the piston 36 increases, which causes local wear and causes a decrease in reliability, and also causes a decrease in efficiency due to an increase in input.

The present invention has been made in view of these points, and an object of the present invention is to provide a closed compressor having improved efficiency and refrigerating capacity while maintaining reliability, and a freezing device using the same. is there.

In order to achieve the above object, the present invention has a cylindrical seal portion forming a sliding surface on the outer peripheral surface of the piston, is located behind the seal portion, has the same radius as the seal portion, and is applied to the piston. It is provided with a sliding portion that supports lateral pressure, and the sliding portion is provided with a plurality of dimple-shaped recesses.

As a result, the sliding area of the piston can be reduced without narrowing the width of the sliding portion and expanding the area of step drop, so that the sliding loss can be reduced, high efficiency can be achieved, and the piston can be cylinderd. Since it is less likely to tilt in the vertical direction, leakage of the refrigerant gas can be suppressed and a decrease in refrigerating capacity can be prevented. Moreover, since the surface pressure generated in the sliding portion when the piston is tilted is reduced, local wear can be reduced. In addition, the lubricating oil scattered from the upper end of the eccentric shaft portion is stored in the recess provided in the sliding portion and supplied from the recess to the sliding portion and the sealing portion to lubricate the sliding surface and improve the sealing action. It can be ensured and the occurrence of wear of the load supporting portion can be prevented.

According to the above-described configuration, the present invention reduces leakage of refrigerant gas between the piston and the cylinder, reduces sliding loss to improve efficiency, and prevents wear of the piston seal portion and sliding portion. As a result, reliability can be improved, and a closed compressor having high efficiency and refrigerating capacity and a refrigerating apparatus using the same can be obtained.

Longitudinal sectional view of the closed compressor according to the first embodiment of the present invention. Top sectional view of the closed compressor in the same embodiment Cross-sectional view of the main part around the cylinder at bottom dead center in the same embodiment Side view of the piston in the same embodiment Characteristic diagram showing the load acting on the side surface of the piston in the same embodiment Side view showing the piston of the closed type compressor in Embodiment 2 of this invention. Schematic sectional view of the refrigerating apparatus according to the second embodiment of the present invention. Longitudinal section of a conventional sealed compressor External view showing the piston of a conventional sealed compressor Cross-sectional view of the main part showing the vicinity of the cylinder of the conventional closed compressor

The closed compressor of the first invention stores lubricating oil in a closed container, and also houses an electric element having a stator and a rotor and a compression element arranged above the electric element. The compression element includes a shaft having a main shaft portion to which the rotor is fixed, an eccentric shaft portion, and a refueling mechanism, a cylinder block including a main bearing and a cylinder that pivotally support the main shaft portion of the shaft, and the cylinder block. It is composed of a piston that is reciprocally inserted inside the cylinder and a connecting means that connects the piston and the eccentric shaft portion, and the outer peripheral surface of the piston is a cylindrical seal that forms a sliding surface. A portion and a sliding portion located behind the seal portion, having the same radius as the seal portion, and supporting the lateral pressure applied to the piston, and the sliding portion has a plurality of dimple-shaped recesses. It is a structure that forms.

As a result, the sliding area of the piston can be reduced without narrowing the width of the sliding portion and expanding the area of step drop, so that the sliding loss can be reduced and the efficiency can be improved. .. Further, since the piston is less likely to tilt in the vertical direction with respect to the cylinder, leakage of the refrigerant gas can be suppressed and a decrease in volumetric efficiency can be prevented. Moreover, since the surface pressure generated in the sliding portion when the piston is tilted is reduced, local wear can be reduced. In addition, the lubricating oil scattered from the upper end of the eccentric shaft portion is stored in the recess of the sliding portion and supplied from the recess to the sliding portion and the sealing portion to lubricate the sliding surface and ensure the sealing action. At the same time, it is possible to prevent the occurrence of wear of the load supporting portion. As a result, a closed compressor with high reliability, high efficiency and high refrigerating capacity can be obtained.

A second invention, particularly in the first invention, is a dimple formed on a sliding portion of the piston, where the load side is the direction in which the piston is pressed by the connecting means when the piston heads for top dead center. The area ratio on the non-load side of the plurality of concave portions is 1.2 times higher than the area ratio on the load side.

As a result, by selecting the area ratio according to the magnitude of the load acting in the lateral direction of the piston due to the compression action, the area of the sliding surface is minimized while ensuring reliability, and the sliding loss is reduced. , Efficiency can be improved.

In the third invention, particularly in the first or second invention, the depth of the plurality of dimple-shaped recesses in the piston is deepest on the tip end side of the piston and gradually becomes shallower as the distance from the tip end side of the piston increases. It is as a configuration.

As a result, a large amount of lubricating oil scattered from the upper end of the eccentric shaft portion can be stored in the deepest part of the recess, and when the piston moves from the bottom dead center to the top dead center, the distance from the tip side of the piston increases. The shallow shape causes a wedge effect, can increase the lubricating action on the side surface of the piston, reduce the sliding loss of the sliding part of the piston, and prevent the occurrence of wear on the sliding surface. However, the efficiency and reliability of the closed compressor can be improved more effectively.

The fourth invention is a configuration in which the surface of the piston is subjected to a surface treatment containing a synthetic resin as a component, particularly in any one of the first to third inventions.

As a result, the surface treatment containing synthetic resin improves durability, reduces the sliding area and reduces sliding loss, and damages even if the surface pressure on the side surface of the piston increases under high load conditions. This can be prevented and the reliability of the closed compressor can be further improved.

A fifth invention, particularly in any one of the first to fourth inventions, has a configuration in which the electric element is driven by an inverter circuit at a plurality of rotation speeds.

As a result, highly reliable and efficient operation can be performed in a wide range. That is, even if the supply of the lubricating oil to the piston decreases due to the operation at a low rotation speed, the lubricating oil can be stored in the concave portion, and by supplying the lubricating oil from the concave portion to the sliding portion or the sealing portion, the sliding surface is lubricated. It is possible to ensure the sealing action and prevent the occurrence of wear of the load supporting portion, and it is possible to operate with high reliability and efficiency in the entire range from low rotation to high rotation.

The sixth invention is a refrigerating apparatus, and the refrigerating apparatus is configured to use the closed compressor according to any one of the first to fifth inventions.

As a result, the efficiency and reliability of the closed compressor are high, so that the power consumption of the refrigerating apparatus can be reduced and the reliability can be made high.

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

(Embodiment 1)
FIG. 1 is a vertical sectional view of the closed compressor according to the first embodiment of the present invention, FIG. 2 is a top sectional view of the closed compressor according to the same embodiment, and FIG. 3 is a bottom dead center view of the same embodiment. A cross-sectional view of a main part around the cylinder, FIG. 4 is a side view of the piston in the same embodiment, and FIG. 5 is a characteristic diagram showing a load acting on the side surface of the piston in the same embodiment.

In FIGS. 1 to 4, the closed compressor stores the lubricating oil 104 inside the closed container 102, and is filled with R600a (isobutane), which is a refrigerant gas having a low global warming coefficient. The compressor body 106 is suspended in the closed container 102 by a suspension spring 108.

The compressor main body 106 includes an electric element 110 and a compression element 112 driven by the electric element 110, and a power supply terminal 113 for supplying power to the electric element 110 is attached to the closed container 102.

The compression element 112 arranged above the electric element 110 is composed of a shaft 118, a cylinder block 124, a piston 136, a connecting means 123, and the like.

The shaft 118 includes a spindle portion 120 and an eccentric shaft portion 122 extending from the upper end of the spindle portion 120 and parallel to the spindle portion 120, and the lubricating oil 104 stored in the bottom portion of the closed container 102 is used as the lower end of the spindle portion 120. It is provided with a refueling mechanism 130 that supplies oil from the eccentric shaft portion 122 to the upper end.

The refueling mechanism 130 is composed of a spiral groove 128 or the like formed on the outer surface of the spindle portion 120.

The cylinder block 124 includes a main bearing 126, and the main shaft portion 120 of the shaft 118 is inserted into the main bearing 126 in a rotatable state to support the main bearing 126.

Further, the cylinder block 124 is provided with a cylinder 134 which is a cylindrical hole, and a piston 136 is reciprocally inserted into the cylinder 134.

The connecting means 123 connects the eccentric shaft portion 122 and the piston 136 by inserting the holes provided at both ends into the piston pin 143 (see FIG. 2) attached to the piston 136 and the eccentric shaft portion 122, respectively. doing.

A valve plate 146 is attached to the end surface of the cylinder 134 to form a compression chamber 148 together with the cylinder 134 and the piston 136. Here, in the compression element 112, the load applied to the piston 136 when compressing the refrigerant gas acts on the eccentric shaft portion 122 via the connecting means 123, and the load acting on the eccentric shaft portion 122 is applied to the eccentric shaft portion 122. It has a structure of a cantilever bearing supported by a spindle portion 120 and a spindle bearing 126 arranged on the lower side.

Further, the cylinder head 150 is fixed to the cylinder 134 so as to cover the valve plate 146 and cover the cylinder 134.

Further, a suction muffler 152 formed of a resin such as PBT to form a muffling space inside is attached under the cylinder head 150.

The electric element 110 is composed of a stator 114 fixed below the cylinder block 124 and a rotor 116 arranged on the inner diameter side of the stator 114 and fixed to the spindle 120 by a method such as shrink fitting. It is a DC brushless motor. The stator 114 is configured by directly winding a winding (not shown) around a plurality of magnetic pole teeth of an iron core in which steel plates are laminated via an insulating material, and the rotor 116 is a permanent magnet (not shown). ) Is built-in.

Further, the winding of the stator 114 is connected to an inverter circuit (not shown) outside the sealed compressor via the power supply terminal 113 by a conducting wire, so that the sealed compressor of the present embodiment has a plurality of sealed compressors. It is driven by the number of revolutions.

Next, the configuration of the piston 136 will be described in detail with reference to FIG.

The piston 136 is provided with a seal portion 137, a sliding portion 140, and a step drop 139 from the cylinder head 150 side on the outer peripheral surface thereof. The seal portion 137 is a sliding surface formed in a cylindrical shape so as to have a small clearance with respect to the inner peripheral surface of the cylinder 134, and the sliding portion 140 has the same radius as the seal portion 137 and is behind the seal portion 137. It is a sliding surface continuously provided on the side, and the step drop 139 is a cutout portion provided so that the radius is smaller than that of the sliding portion 140.

Here, the sliding portion 140 is provided with a plurality of dimple-shaped recesses 142. The depth of the recess 142 is about 0.2 mm on average. The recesses 142 are arranged in a staggered pattern, and in this example, they have an elliptical shape. Further, the area ratios of the plurality of dimple-shaped recesses 142 provided in the sliding portion 140 are different on the left and right when viewed from the upper part of the compressor. Specifically, when the piston 136 moves from the bottom dead center to the top dead center and compresses the refrigerant gas, the piston 136 is pressed against the inner wall of the cylinder 134 by the connecting means 123, and a load is applied to the sliding surface. The area ratio A of the recess 142 on the opposite side (upward direction in FIG. 3, hereinafter referred to as the load side) is lower than the area ratio B of the recess 142 on the opposite side (upward direction in FIG. 3, hereinafter referred to as the load side). Specifically, the area ratio B is about 1.6 times the area ratio A. Further, the depth of the recess 142 is made deepest on the tip end side of the piston 136, and gradually becomes shallower as the distance from the tip end side of the piston 136 increases.

Further, the outer peripheral surface of the piston 136 is subjected to a surface treatment containing a synthetic resin as a component. This is because so-called engineering plastics such as polytetrafluoroethylene (PTFE), polyamide-imide (PAI) containing solid lubricants such as graphite and molybdenum disulfide, and polyetheretherketone (PEEK) have heat resistance and chemical resistance. , Excellent from the viewpoint of resistance when sliding.

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

When the electric element 110 is energized from the power supply terminal 113, the rotor 116 rotates together with the shaft 118 in the direction of the arrow in FIG. 2 due to the magnetic field generated in the stator 114. The eccentric rotation of the eccentric shaft portion 122 accompanying the rotation of the spindle portion 120 is converted by the connecting means 123, and the piston 136 is reciprocated in the cylinder 134. Then, as the volume of the compression chamber 148 changes, the refrigerant gas in the closed container 102 is sucked into the compression chamber 148, and then the compression operation is performed.

Here, when the piston 136 moves from the bottom dead center to the top dead center in this compression stroke, the piston 136 receives the compressive load of the refrigerant gas, and the shaft 118 is strongly pushed in the opposite direction of the piston 136 via the connecting means 123. As a result, the shaft 118 bends. As a result, a force that greatly tilts the piston 136 in the vertical direction acts.

The large vertical tilting force acting on the piston 136 is mainly received by the sliding portion 140, but since the sliding portion 140 is provided with a plurality of recesses 142 to reduce the sliding area, it is generated in the sliding portion 140. Sliding loss can be reduced.

Further, since the boundary edge 141 is moved to the center side of the piston 136 with respect to the vertical direction of the compressor, in other words, the width of the sliding portion 140 is not narrowed, the angle at which the piston 136 is tilted is increased. Can be suppressed. Therefore, since the gap between the seal portion 137 of the piston 136 and the cylinder 134 does not become large, it is possible to prevent an increase in the amount of refrigerant gas leaking from the top dead center side to the bottom dead center side of the piston 136 and suppress a decrease in refrigerating capacity.

Furthermore, since the inclination angle of the piston 136 does not increase, the surface pressure near the boundary edge 141 of the piston 136 does not increase, local wear can be suppressed, reliability is prevented from being lowered, and input is reduced for efficiency. Can be improved.

Further, when performing the compression operation, an acting force acts on the piston 136 via the connecting means 123 that connects the eccentric shaft portion 122 and the piston pin 143, and the piston 136 is pressed against the side surface of the cylinder 134. That is, since the piston 136 reciprocates against the pressure of the compression chamber 148 and the inertial force of the piston 136, the acting force acting on the piston 136 acts in an oblique direction with respect to the axial direction of the cylinder 134, and this component force causes the piston 136 to reciprocate. The piston 136 will be pressed against the side surface of the cylinder 134.

FIG. 5 is a characteristic diagram showing the state of the load in which the piston 136 is pressed against the side surface of the cylinder 134 during one rotation of the spindle portion 120. In the figure, the upper direction shows the load side load and the lower direction shows the counterload side load. In addition, the characteristics shown by the broken line are the loads when driven at a low rotation speed under normal operating pressure conditions, and the solid line shows the load under conditions when driven at a high rotation speed under high operating pressure conditions. ing.

The lateral pressure load applied to the piston 136 varies depending on the operating pressure conditions, the number of rotations, the mass of parts such as the piston 136, the amount of offset between the cylinder 134 and the shaft of the main bearing 126, etc., but in general, the load on the load side is counterproductive. Often larger than the load side. In the case of the high pressure and high rotation speed conditions shown by the solid line in FIG. 5, the ratio of the maximum values of the loads on the load side and the non-load side is about 1.6: 1.

Therefore, the area ratio B of the recess should be increased at least 1.2 times to 2 times the area ratio A. If it is 1.2 times or less, the sliding loss reduction effect is small, and if it is 2 times or more, the surface pressure on the counterload side rises too much. More preferably, the area ratio B of the recess is about 1.6 times ± 10% of the area ratio A, and in this case, the surface pressure when the maximum load is applied can be made the same, so that the durability is sufficient. The sliding area can be minimized while ensuring the property.

In the suction stroke accompanying the compression operation, the refrigerant gas in the closed container 102 is intermittently sucked into the compression chamber 148 via the suction muffler 152, compressed in the compression chamber 148, and then the high temperature and high pressure refrigerant. The gas is sent to the refrigeration cycle (not shown) from the closed container 102 via the discharge pipe 149 or the like.

Further, due to the action of the oil supply mechanism 130 accompanying the rotation of the shaft 118, the lubricating oil 104 stored in the bottom of the closed container 102 is conveyed upward from the lower end of the shaft 118 and scattered from the tip of the eccentric shaft portion 122.

Here, a part of the scattered lubricating oil 104 adheres to the recess 142 of the piston 136 exposed to the outside of the cylinder 134 near the bottom dead center. After that, the recess 142 is pulled back into the cylinder 134 with the reciprocating motion of the piston 136, so that the lubricating oil 104 more reliably lubricates the sliding surfaces of the piston 136 and the cylinder 134. As a result, the airtightness of the compression chamber 148 can be maintained well at the seal portion 137, and the lubrication state of the sliding portion 140 on which a particularly large load acts can be improved, so that the occurrence of wear can be prevented. And the reliability can be improved.

Further, since the depth of the recess 142 is deepest on the tip side of the piston 136 and gradually becomes shallower as the distance from the tip side of the piston 136 increases, the lubricating oil adhered to the recess 142 near the bottom dead center of the piston 136. After that, when the piston 136 moves to the top dead center due to the reciprocating motion of the piston 136, the wedge effect is generated and the sliding portion 140 can be more reliably lubricated. Therefore, it is possible to improve the lubrication state of the sliding portion 140 on which a particularly large load acts, prevent the occurrence of wear, and improve the reliability.

In the embodiment of the present embodiment, the shape of the concave portion is elliptical, but the same effect can be obtained with a perfect circle, a rectangle, or a triangle.

Further, since the surface of the piston 136 is subjected to a surface treatment containing a synthetic resin as a component, the sliding loss can be further reduced even if the sliding area is small, and as a result, the input can be reduced. , Efficiency can be improved. Further, even if the surface pressure of the sliding surface becomes high under the condition of high operating pressure, damage can be prevented by the surface treatment, so that the reliability can be improved.

(Embodiment 2)
FIG. 6 is a side view showing the piston of the closed compressor according to the second embodiment.

In the piston 160 of this embodiment, step-down 162 is formed on the upper side surface and the lower side surface thereof so as to communicate with the space in the closed container at least near the bottom dead center, and the step-down of the upper side surface and the lower side surface is formed. A sliding portion 166 is formed between 162.

Even in such a shape, by forming the recess 168 in the sliding portion 166, the same effect as that of the first embodiment can be obtained.

(Embodiment 3)
FIG. 7 is a schematic cross-sectional view of the refrigerating apparatus according to the second embodiment of the present invention.

In FIG. 7, the heat insulating box 180 is injected with a heat insulating body 186 that is foam-filled in a space composed of an inner box 182 that is vacuum-formed of a resin body such as ABS and an outer box 184 that uses a metal material such as a precoated steel plate. It has a heat insulating wall. As the heat insulating body 186, for example, rigid urethane foam, phenol foam, styrene foam, or the like is used. It is even better to use a hydrocarbon-based cyclopentane as the foaming material from the viewpoint of preventing global warming.

The heat insulating box 180 is divided into a plurality of heat insulating sections, and has a structure in which the upper part is a rotary door type and the lower part is a drawer type. From the top, there are a refrigerating room 188, a drawer-type switching room 190 and an ice-making room 192 provided side by side, a drawer-type vegetable room 194, and a drawer-type freezing room 196. Insulation doors are provided in each insulation section via gaskets. From the top, there are a refrigerating room rotating door 198, a switching room drawer door 200, an ice making room drawer door 202, a vegetable room drawer door 204, and a freezing room drawer door 206. Further, the outer box 184 of the heat insulating box body 180 includes a recessed portion 208 that is recessed behind the top surface.

The refrigeration cycle consists of a closed compressor 210 elastically supported in the recess 208, a condenser (not shown) provided on the side surface of the heat insulating box 180, a capillary 212 as a decompressor, and water removal. A dryer (not shown), an evaporator 216 provided with a cooling fan 214 arranged in the vicinity on the back surface of the vegetable compartment 194 and the freezer compartment 196, and a suction pipe 218 are connected in a ring shape. .. The closed compressor 210 is composed of the closed compressor described in the first embodiment.

The operation and operation of the refrigerating apparatus configured as described above will be described below.

First, the temperature setting and cooling method of each heat insulating section will be described. The refrigerating chamber 188 is usually set at 1 to 5 ° C. with a lower limit of a temperature at which it does not freeze for refrigerated storage.

The temperature setting of the switching chamber 190 can be changed by the user's setting, and a predetermined temperature setting can be set from the freezing chamber temperature zone to the refrigerating and vegetable chamber temperature zones.

Further, the ice making chamber 192 is an independent ice storage chamber, which is provided with an automatic ice making device (not shown) to automatically prepare and store ice. Although it is a freezing temperature range for storing ice, it is also possible to set a freezing temperature of -18 ° C to -10 ° C, which is relatively higher than the freezing temperature range for the purpose of storing ice.

The vegetable compartment 194 is often set to 2 ° C. to 7 ° C., which is set to a temperature equal to or slightly higher than that of the refrigerator compartment 188. It is possible to maintain the freshness of leafy vegetables for a long period of time as the temperature is lowered to the extent that it does not freeze.

The freezing chamber 196 is usually set at 22 to -18 ° C for freezing storage, but may be set at a low temperature of, for example, -30 or -25 ° C for improving the freezing storage state.

Each chamber is separated by a heat insulating wall in order to efficiently maintain different temperature settings, but it is possible to integrally foam and fill with a heat insulating body 186 as a method of improving heat insulating performance at low cost. Compared to using a heat insulating member such as Styrofoam, the heat insulating performance can be about twice as high, and the storage volume can be expanded by making the partition thinner.

Next, the operation of the refrigeration cycle will be described.

The cooling operation is started and stopped by signals from the temperature sensor (not shown) and the control board according to the set temperature in the refrigerator. The sealed compressor 210 performs a predetermined compression operation according to the instruction of the cooling operation, and the discharged high-temperature and high-pressure refrigerant gas is radiated by a condenser (not shown) to be condensed and liquefied, and is depressurized by the capillary 212. It becomes a low-temperature low-pressure liquid refrigerant and reaches the evaporator 216.

By the operation of the cooling fan 214, heat is exchanged with the air in the refrigerator, the refrigerant gas in the evaporator 216 is evaporated and vaporized, and the heat-exchanged low-temperature cold air is distributed by a damper (not shown) in each room. Is cooled.

By mounting the closed compressor shown in the first embodiment in which the sliding loss is reduced and the efficiency is improved in the refrigerating apparatus performing the above operation, the power consumption of the refrigerating apparatus can be reduced.

Further, since the reliability of the sealed compressor is improved, the reliability of the refrigerating device can also be improved.

As described above, the present invention is a closed compressor having high efficiency and freezing capacity while improving reliability by reliably refueling the sliding surface while reducing the sliding area of the piston. A freezing device using the above can be provided. Therefore, it can be widely applied not only to household electric refrigerators and freezers, but also to air conditioners, vending machines, other refrigerating devices, and their sealed compressors.

102 Sealed container 104 Lubricating oil 110 Electric element 112 Compressing element 114 Stator 116 Rotor 118 Shaft 120 Main shaft part 122 Eccentric shaft part 123 Connecting means 124 Cylinder block 126 Main bearing 130 Refueling mechanism 134 Cylinder 136, 160 Piston 137 Seal part 139, 162 Step drop 140, 166 Sliding part 142, 168 Recess 210 Sealed compressor

Claims (6)

Lubricating oil is stored in a closed container, and an electric element having a stator and a rotor and a compression element arranged above the electric element are housed, and the rotor is fixed to the compression element. A shaft having a main shaft portion, an eccentric shaft portion, and a refueling mechanism, a cylinder block including a main bearing and a cylinder that pivotally support the main shaft portion of the shaft, and a cylinder block reciprocating inside the cylinder are inserted. It is composed of a piston and a connecting means for connecting the piston and the eccentric shaft portion, and the outer peripheral surface of the piston is located behind the cylindrical seal portion forming the sliding surface and the seal portion. , A sealed compressor having the same radius as the seal portion, provided with a sliding portion for supporting the lateral pressure applied to the piston, and having a plurality of dimple-shaped recesses formed in the sliding portion. When the piston is pressed toward the top dead center and the direction in which the piston is pressed by the connecting means is the load side, the area ratio on the counterload side of the plurality of dimple-shaped recesses formed in the sliding portion of the piston is loaded. The closed compressor according to claim 1, wherein the area ratio on the side is 1.2 times or more higher. The closed compressor according to claim 1 or 2, wherein the depth of the dimple-shaped concave portion is deepest on the tip end side of the piston and gradually becomes shallower as the distance from the tip end side of the piston increases. The closed compressor according to any one of claims 1 to 3, wherein the surface of the piston is subjected to a surface treatment containing a synthetic resin as a component. The sealed compressor according to any one of claims 1 to 4, wherein the electric element is driven by an inverter circuit at a plurality of rotation speeds. A refrigerating apparatus using the sealed compressor according to any one of claims 1 to 5.

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