JP4396401B2 - Hermetic compressor - Google Patents

Description

  The present invention relates to a refrigeration cycle having no gas-liquid separator.

Conventionally, as one of countermeasures against defloning of refrigerants used in the refrigeration cycle, for example, a refrigeration cycle shown in FIG. 3 using carbon dioxide (CO 2) as described in Patent Document 1 has been proposed. That is, the compressor 101 compresses gas-phase CO 2, and the high-temperature and high-pressure supercritical CO 2 is cooled by a radiator (gas cooler) 102. Then, the pressure is reduced by the pressure reducer 103, the CO2 in a gas-liquid two-phase state is evaporated by the evaporator 104, and latent heat of evaporation is taken from the external fluid such as air to cool the external fluid.

  Incidentally, the supercritical state refers to a state in which the CO2 molecules move like a gas phase state while the density is substantially equal to the liquid density. However, since the critical temperature of CO2 is about 31 ° C., which is lower than the critical temperature of conventional chlorofluorocarbon (for example, 112 ° C. for R12), the CO2 temperature on the radiator side becomes higher than the critical point temperature of CO2. That is, CO 2 is not condensed even on the outlet side of the radiator 102.

On the other hand, when the liquid refrigerant is sucked during the operation of the compressor 101, since the lubricating oil in the compression chamber inside the compressor is washed away with the liquid refrigerant, damage due to insufficient lubrication is caused. A gas-liquid separator 105 such as an accumulator is disposed between the compressor 101 and the compressor 101 to prevent the liquid phase refrigerant from being sucked into the compressor.
JP-A-11-94380

  By the way, this gas-liquid separator returns the liquid-phase refrigerant to the compressor that occurs in the transient state of the refrigeration cycle (for example, during the start-up in the low temperature state or during the restart after the compressor stops). A sufficient volume of the liquid reservoir is required with respect to the amount, but it is desirable to make it as small as possible from the viewpoint of saving the space of the equipment and reducing the material cost. However, the gas-liquid separator in the case where the operating pressure is high as in the CO2 refrigeration cycle is difficult to reduce in size because the thickness of the container is increased particularly in order to ensure the pressure resistance of the container.

  An object of the present invention is to provide a hermetic compressor capable of reducing the size and cost of an apparatus without providing a gas-liquid separator and preventing damage to the compressor. To do.

  In order to solve the above-described conventional problems, a hermetic compressor of the present invention is a compressor of a refrigeration cycle that does not have a gas-liquid separator, and a compressor is provided at a suction hole portion that connects a suction pipe and a compression chamber of the compressor. An oil sump that separates and collects the lubricating oil that is sucked in and mixed with the refrigerant gas returning from the outside through the suction pipe is provided, and together with the liquid phase refrigerant sucked when the liquid phase refrigerant returns to the compressor, The lubricating oil is configured to be supplied to the compression chamber.

  As a result, even if the liquid refrigerant flows into the compressor during the transient state of the refrigeration cycle, the lubricating oil in the oil sump is mixed and supplied to the compression chamber, so that insufficient compression of the compression chamber can be prevented.

  In the hermetic compressor of the present invention, the area of the suction hole at the position where the oil reservoir is provided is larger than the inner diameter area of the suction pipe.

  As a result, the flow rate of the oil droplets flowing in the suction pipe mixed with the gas phase refrigerant during the stable operation of the refrigeration cycle is reduced in the vicinity of the suction hole of the oil reservoir, so that the lubricating oil is effectively removed. The oil can be separated and the lubricating oil can be stored in the oil reservoir.

  In the hermetic compressor of the present invention, the area of the suction hole connected to the compression chamber is smaller than the area near the position where the oil reservoir is provided.

  Accordingly, the lubricating oil flowing along the inner wall of the suction pipe during stable operation of the refrigeration cycle can be effectively collected in the suction hole near the oil reservoir, and the lubricant can be stored in the oil reservoir.

  The hermetic compressor of the present invention provides a hermetic compressor capable of reducing the size and cost of the apparatus without providing a gas-liquid separator in the refrigeration cycle, and preventing damage to the compressor. it can.

According to a first aspect of the present invention, there is provided a compression mechanism portion comprising a compression member and a main bearing member in a sealed container, an electric motor portion for driving the compression mechanism portion, and a lubricating oil reservoir at the bottom of the sealed container, A compression chamber that compresses gas, a suction hole that connects a suction pipe that connects the compression chamber and the outside of the compressor, and a refrigerant that returns from the outside of the compressor through the suction pipe to the vicinity of the suction hole. Stabilize the refrigeration cycle by providing an oil reservoir that separates and collects lubricating oil that is sucked in mixed with gas, and that the area of the suction hole where the oil reservoir is located is larger than the inner diameter area of the intake pipe. Since the flow rate of the oil droplets flowing through the suction pipe mixed with the refrigerant gas in the state becomes slow near the suction hole of the oil reservoir, the lubricating oil can be effectively separated and the lubricating oil can be added to the oil reservoir. Can be stored. In addition, the area of the suction hole connected to the compression chamber is made smaller than the area of the suction hole near the oil reservoir, so that the lubricating oil flowing along the inner wall of the suction pipe can be effectively removed near the oil reservoir when the refrigeration cycle is stable. Lubricating oil can be collected in the oil reservoir and collected in the suction hole. In this way, the lubricating oil stored in the oil reservoir is supplied to the compression chamber together with the liquid-phase refrigerant sucked when the liquid-phase refrigerant returns to the compressor, so that the compressor is in a transient state of the refrigeration cycle. Even if liquid phase refrigerant flows in sometimes, the lubricating oil in the oil reservoir is mixed and supplied to the compression chamber, so that insufficient compression of the compression chamber can be prevented.

  According to a second aspect of the present invention, there is provided a hermetic compressor according to the first aspect of the present invention, wherein the oil reservoir is composed of an opening and a reservoir, and the area of the opening is smaller than the area of the reservoir. Even when the liquid phase refrigerant flows in during the transient state of the refrigeration cycle, the lubricating oil in the oil reservoir gradually flows out into the compression chamber, so that the lubricating oil can be supplied to the liquid phase refrigerant for a long time.

  According to a third aspect of the invention, in particular, in the hermetic compressor according to the first aspect of the invention, the oil reservoir portion is a communication hole provided in the suction hole of the compression member, and the concave portion provided in the main bearing member is the reservoir portion. Therefore, the oil sump portion can be constructed at a low cost.

  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)
FIG. 1 shows a sectional view of a hermetic compressor 50 according to an embodiment of the present invention.

  In FIG. 1, a compression mechanism unit 2 and an electric motor 3 for driving the compression mechanism unit 2 are arranged in a vertical direction in a sealed container 1. The electric motor 3 includes a stator 4 fixed inside the closed container 1 by shrink fitting or welding, and a rotor 5 that is rotatably positioned inside the stator 4. The drive shaft 6 is coupled in a penetrating state. One end of the drive shaft 6 facing upward is rotatably supported by a bearing 8 fixed to a main bearing member 7 as a fixing member constituting a part of the compression mechanism portion 2. A crankshaft 9 that performs eccentric motion with respect to the drive shaft 6 is provided at the tip of the drive shaft 6 that is supported by the bearing 8.

On the other hand, the compression mechanism section 2 includes a fixed scroll 10 (hereinafter referred to as a compression member) in which a spiral-shaped fixed wrap 10b rises from the fixed end plate 10a, and a revolving scroll 11 in which a spiral-shaped revolving wrap 11b rises from the revolving end plate 11a. And a plurality of compression chambers 32 are formed between the two, the compression member 10 is fixed to the main bearing member 7, and
The orbiting scroll 11 is sandwiched between them and backed up by the main bearing part 7 via the rotation prevention mechanism 12.

  In this state, the rotation of the orbiting scroll 11 is prevented by the rotation preventing mechanism 12, and only the orbiting motion along the circular orbit via the orbiting bearing 13 in which the orbiting scroll 11 is joined to the orbiting scroll 11 by the crankshaft 9. Let As a result, the compression chamber 32 sucks refrigerant gas or the like from the suction hole 14 provided in the peripheral portion of the compression member 10 while moving from the peripheral portion toward the center of the turning wrap 11b and the fixed wrap 10b while reducing the volume. And compress. The compressed refrigerant gas or the like passes through the discharge hole 15 in the center of the compression member 10 and is discharged into the space 16 in the sealed container 1. The refrigerant gas discharged into the sealed container 1 passes through the details of the electric motor 3 and cools it. Then, the refrigerant gas is discharged out of the sealed container 1 through the discharge pipe 17 and supplied to the refrigeration cycle shown in FIG. Here, components having the same functions as those of the conventional refrigeration cycle among the components of the refrigeration cycle shown in FIG. The conventional gas-liquid separator 105 is not provided in this refrigeration cycle. The refrigerant gas that has passed through the refrigeration cycle is returned to the suction hole 14 through the suction pipe 18 and repeatedly used thereafter.

  The other end of the drive shaft 6 facing downward is rotatably supported by a sub-bearing 19 provided in a sub-bearing part 36 fixed in the sealed container 1 by shrink fitting or welding. 6 is provided with a lubrication mechanism 37 using a positive displacement pump 20 at the tip on the other end side. The lubrication mechanism 37 sucks lubricating oil from the lubricating oil reservoir 21 by the pump 20, and the center of the orbiting scroll 11 positioned at the upper part of the crankshaft 9 through the oil supply passage 22 provided in the axial direction at the center of the drive shaft 6. The oil is supplied to the lubricating oil reservoir 23 located on the back of the unit. The supply pressure of the lubricating oil to the lubricating oil reservoir 23 is set to be substantially equal to the discharge pressure of the compression mechanism unit 2, and the orbiting scroll 11 is separated from the compression member 10 when the compression mechanism unit 2 compresses the refrigerant gas. Give back pressure to prevent.

  The lubrication mechanism 37 has a lubrication path 37a that lubricates the bearing 8 through the one lubrication oil pool 24 after the lubrication oil supplied to the lubrication oil pool 23 is lubricated and cooled in the slewing bearing 13, and in the lubrication path 37a. The lubricating oil after lubrication exudes to the lower part of the compression mechanism part 2 mainly by supply pressure or gravity, and returns to the lubricating oil storage part 21 for recirculation. The lubricating mechanism 37 further supplies a part of the lubricating oil supplied to the lubricating oil reservoir 23 to the sliding portion between the rotation preventing mechanism 12, the main bearing part 7 and the orbiting scroll 11 through the throttle portion 25. It flows into the compression chamber 32 and is mixed with the refrigerant gas. Most of the lubricating oil mixed with the refrigerant gas is discharged into the sealed container 1 together with the refrigerant gas, separated from the refrigerant gas, and then returned to the lubricating oil reservoir 19. The lubricating oil that has not been separated in the sealed container 1 is discharged together with the refrigerant gas from the discharge pipe 17 to the outside of the sealed container 1 and supplied to the refrigeration cycle. Come back again.

Here, in the vicinity of the suction hole 14 of the compression member 10, there are an opening 26 a communicating with the suction hole 14, and a reservoir 26 b having an area larger than the area of the opening 26 a and provided in the main bearing member 7. The oil sump part 26 comprised combining these is provided. On the other hand, the area of the suction hole 14 in the vicinity where the oil reservoir 26 is provided is formed larger than the inner diameter area of the suction pipe 18 and a step portion is provided in a portion connected to the compression chamber 32, so that the compressor is in normal operation. The oil droplet-like lubricating oil flowing mixed with the refrigerant gas returning from the suction pipe 18 is separated from the refrigerant gas due to the slow flow velocity at the suction hole 14, and flows back along the inner wall of the suction pipe 18. The lubricating oil is dammed up at the stepped portion of the suction hole 14 connected to the compression chamber 32 and collected in the suction hole 14 in the vicinity of the oil reservoir 26. The collected lubricating oil is stored by its own weight in the reservoir 26b through the opening 26a. The accumulated lubricating oil is supplied from the suction pipe 18 of the liquid-phase refrigerant that is generated when the refrigeration cycle is in a transient state (for example, during a low temperature state or when the compressor is restarted after being stopped). When returning to the compressor, the specific gravity of the liquid-phase refrigerant is larger than that of the gas-phase refrigerant, so that the liquid-phase refrigerant flows into the reservoir 26b from the opening 10a and is mixed with the lubricating oil in the reservoir 26b. The flow-out compression chamber 32 is supplied. For this reason, the liquid refrigerant containing a large amount of lubricating oil is compressed into the compression chamber 32.
The shortage of lubricating oil in the compression chamber 32 is eliminated. Further, since the opening portion 26a is configured to be smaller than the area of the reservoir portion 26b, the lubricating oil mixed with the liquid phase refrigerant gradually flows out to the suction hole 14, so that the lubricating oil can be supplied to the liquid phase refrigerant for a long time. . Furthermore, since the oil reservoir 26 is configured by combining the opening 26a provided in the compression member 10 and the reservoir 26b provided in the main bearing member 7, it can be provided at low cost.

  As described above, the hermetic compressor according to the present invention reduces the size and cost of an apparatus without providing a gas-liquid separator in the refrigeration cycle, and the liquid phase refrigerant returns from the refrigeration cycle to the compressor. In addition, it is possible to provide a hermetic compressor that can prevent damage to the compressor.

  The hermetic compressor is not limited to a refrigeration cycle that does not include a gas-liquid separator, and has the same effect when the liquid-phase refrigerant returns when a small accumulator is provided. Furthermore, the hermetic compressor is not limited to a scroll compressor, and can be used for a rolling piston compressor and other types of compressors.

The longitudinal cross-sectional view of the hermetic compressor in the embodiment of the present invention The figure which shows the refrigerating cycle which uses the hermetic compressor in embodiment of this invention. Diagram showing a conventional refrigeration cycle

DESCRIPTION OF SYMBOLS 1 Sealed container 2 Compression mechanism part 3 Electric motor 7 Main bearing member 10 Compression member 14 Suction hole 18 Suction pipe 26 Oil reservoir part 26a Opening part 26b Reservoir part 32 Compression chamber 50 Sealed compressor

Claims (3)

A compression mechanism part composed of a compression member and a main bearing member, a motor part that drives the compression mechanism part, and a lubricating oil reservoir are provided at the bottom of the closed container, and a gas is supplied to the compression mechanism part. A compression chamber for compressing the suction chamber, a suction hole for connecting a suction pipe connecting the compression chamber and the outside of the compressor, and a refrigerant gas returning from the outside of the compressor through the suction pipe in the vicinity of the suction hole for suction. At the same time have been Ru provided an oil reservoir for storing lubricating oil, and greater than the inner diameter area of the area the suction pipe of the suction hole of the position provided with the oil reservoir, and the suction hole of the position connected to the compression chamber The area is made smaller than the area of the suction hole in the vicinity of the oil reservoir, and the lubricating oil in the oil reservoir is supplied to the compression chamber together with the liquid refrigerant sucked when the liquid refrigerant returns to the compressor. Sealed compressor. The hermetic compressor according to claim 1, wherein the oil reservoir includes an opening and a reservoir, and an area of the opening is smaller than an area of the reservoir. 3. The hermetic compressor according to claim 2, wherein the oil reservoir is configured by combining a communication hole provided in the suction hole of the compression member as an opening and a recess provided in the bearing member as a reservoir.