JPS60147593A - Rotary compressor - Google Patents

Abstract

PURPOSE:To enhance the capacity of cooling lubricating oil and permit to pre- cool the compressor sufficiently by a method wherein a communicating hole is provided at a part of the wall of expansion chamber connected to a pre-cooling pipe and a part of said expansion chamber, including said communicating hole, is dipped into the lubricating oil. CONSTITUTION:One ends of the inlet pipe 14a' and the outlet pipe 14b' of the pre-cooling pipes 14' are opened at the outside of an enclosed vassel 4. The inlet pipe 14a' of the pre-cooling pipe 14' is inserted into the expansion chamber 14, designed so as to have a proper capacity, from the lower end thereof while the outlet pipe 14b' is connected to the expansion chamber 14c' so as to be introduced out of the upper end thereof. The expansion chamber 14c' is dipped into the lubricating oil 13 to a proper height from the lower end surface thereof and the lubricating oil 13 invades into the chamber through the communicating hole 14d' provided at the lower end surface and forms an oil surface in the chamber also.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotary compressor that applies high-pressure refrigerant gas within a closed container, and more particularly to a cooling structure for lubricating oil that lubricates a compression mechanism.

The structure of the conventional example and its problems The conventional example will be explained with reference to FIGS. 1 to 3. Reference numeral 1 denotes a compressor main body, which is constructed by sealing a rotary compression mechanism 2 and an electric motor 3 that drives the same in a closed container 4. A cylinder 5 sucks low pressure refrigerant into the cylinder and discharges high pressure refrigerant into the closed container 4 through compression action. 6 is the crankshaft, 7
is a piston attached to the outer periphery of the crankshaft 6, which is inserted into the rotor 3a of the electric motor 3 and performs an eccentric rotation compression action. 8 is a discharge port of the cylinder 5, 9 is a discharge valve, and 10 is a suction port of the cylinder 5.
A suction pipe 11 is directly connected to and passes through the closed container 4. 12 is a discharge pipe for discharging high-pressure refrigerant from the closed container 4; 13 is a lubricating oil for lubricating the rotary compression mechanism 2; 14;
1 is a pre-cooling pipe that cools the lubricating oil 13 to pre-cool the inside of the sealed container 4, a part of which is immersed below the surface of the lubricating oil 13, 15 is a pre-cooling heat exchanger, 16 is a condenser, 17 (l) -1
: Capillary 1 tube, 18 is an evaporator, after being discharged from the discharge pipe 12 of the compressor main body 1, the discharge pipe 12 → pre-cooling heat exchanger 16 → pre-cooling pipe 14 → condenser 16 → capillary #l tube 17 → evaporator 18 → suction pipe 11 constitutes a refrigerating cycle that circulates.

In this configuration, the low-pressure refrigerant sucked into the cylinder 6 through the suction pipe 11 and the suction port 10 is compressed by the zero rotation compression movement of the piston foot, becomes high-pressure refrigerant gas, and pushes the discharge valve 9 up from the discharge port 8. It is once discharged into the closed container 4. Thereafter, the high-temperature, high-pressure refrigerant gas filling the closed container 4 is discharged from the discharge pipe 12 to an external refrigeration cycle, and is heat-exchanged in the pre-cooling heat exchanger 15 to lower the refrigerant temperature. The high-pressure refrigerant gas, whose temperature has been reduced, is then guided to a pre-cooling pipe 14 disposed in the compressor 1, where it exchanges heat with the lubricating oil 13, cooling the high-temperature lubricating oil 13 to a certain extent, and then passing through the condenser 16. After being condensed and liquefied, the pressure is reduced in a capillary tube 17, and then evaporated in an evaporator 18 to cool the inside of a refrigerator or the like. However, when the pre-cooling pipe 14 is composed of a simple pipe as described above, generally the airtight container 4
Since the oil level of the lubricating oil 13 sealed therein was not so high, it was not possible to provide a sufficient length of immersion in the lubricating oil to be effective as a heat exchanger. This is particularly noticeable in the case of a horizontally installed rotary compressor as shown in this conventional example, and the required surface area for heat exchange with the lubricating oil 13 cannot be secured. Furthermore, the inner diameter of the pre-cooling pipe 14 is as small as possible.
Since the flow rate of the refrigerant in the pipe is also high, the capacity of the pre-cooling heat exchanger 16 is sufficiently increased, for example, before the refrigerant is introduced into the pre-cooling pipe 14 .

Even if the refrigerant is in the wet vapor region (liquid and gas mixed state), dynamic (fluid) heat transfer accounts for the majority, and static (retention) heat transfer of the liquid component - absorption of latent heat of vaporization is too much. There were some inconveniences such as unmet expectations, and ultimately the intended purpose of cooling the compressor to increase efficiency or improve reliability could not be fully achieved.

OBJECTS OF THE INVENTION In view of the above points, the present invention aims to improve the cooling ability of lubricating oil by a pre-cooling pipe and sufficiently pre-cool a compressor.

Structure of the Invention In order to achieve this object, the present invention connects an expansion chamber with an appropriate capacity and a communication hole in a part of the chamber wall by interrupting a part of the precooling pipe, and connects this expansion chamber with a communication hole in a part of the chamber wall. By immersing a portion of the lubricating oil under the surface of the lubricating oil, the refrigerant directly cools the lubricating oil that has formed an oil surface also in the expansion chamber, thereby enhancing the cooling effect.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 4 to 7. Note that the same components as those of the conventional example are given the same numbers and detailed explanation thereof will be omitted.

In the figure, 14' is a pre-cooling pipe that connects the inlet vibe 14.
Both ends of the outlet vibrator 14b are opened to the outside of the closed container 4. One shoulder is an expansion chamber set with an appropriate capacity, and the inlet vibrator 142 of the pre-cooling pipe 14' is inserted from the lower end thereof, and the outlet vibrator 14b is led out from the upper end thereof. 14d' is a communication hole provided on the lower surface of the expansion chamber 142. Further, the expansion chamber 14 is immersed under the oil level of the lubricating oil 13 to an appropriate height from its lower end surface, and the communication hole 1
The expansion chamber 14 also has lubricating oil 13 in this chamber via 4d'.
enters and forms an oil surface. The insertion distance of the inlet vibrator 14A of the pre-cooling pipe 14' is set so as to be at least above the oil level of the lubricating oil 13 in the expansion chamber 14c.

Next, regarding the external refrigeration cycle, the compressor discharge pipe 12 → precooling heat exchanger 15 → precooling pipe (inlet vibe 1
42) → Expansion chamber 14c → Pre-cooling pipe (outlet vibe 14b
') → Condenser 16 → Capillary #I pipe 17 → Evaporator 18 → Compressor suction pipe 11 constitutes a circulation cycle.

In this configuration, the high-temperature, high-pressure refrigerant gas compressed in the cylinder S by the rotational compression movement of the piston 7 is discharged into the closed container 4, and then circulated through the discharge pipe 12 to the pre-cooling heat exchanger 15, and the guided by. Pre-cooling pipe 14
The high-pressure refrigerant that has flowed into the inlet vibe 142 of
Filled within two. At this time, there is a communication hole 14 in the expansion chamber 145.
The lubricating oil 13 flows in through d' to form an oil surface, and is sufficiently cooled directly and without any inclusions by the high-pressure refrigerant that flows in and fills the oil surface at a relatively low temperature. When the lubricating oil 13 inside the expansion chamber 142 is cooled, the lubricating oil 13 outside the expansion chamber 142 communicating with the lubricating oil 13 is also sequentially cooled by convection. In addition to this direct cooling, the tube wall of the expansion chamber 14:c is cooled by heat exchange between the filled refrigerant and the tube wall of the expansion chamber 144, which has a large surface area, and the tube immersed under the surface of the lubricating oil 13 cools. The lubricating oil 13 around the immersion part, which cools the wall part by heat conduction, is also indirectly cooled.

Furthermore, since the pressure in the closed container 4 on which the high-pressure refrigerant gas discharged from the discharge port 8 of the cylinder 6 acts is approximately equal to the pressure in the expansion chamber 14c, the oil level of the lubricating oil 13 in the expansion chamber 14c is ''There is no risk that the expansion chamber 142 will rise and the inside of the expansion chamber 142 will be sealed. In fact, since the communication hole 14d' in which the expansion chamber 149 is provided is always sealed under the surface of the lubricating oil 13, a portion of the high-temperature, high-pressure refrigerant gas that has been discharged and filled the airtight container 4 is discharged. There is no possibility that it will bypass the normal circulation route from the pipe 12 and flow into the expansion chamber 140'.

In this way, the lubricating oil 13 is sufficiently cooled directly and indirectly without interfering with the refrigerant circulation cycle, and as a result, the compressor is also sufficiently precooled, improving compression efficiency, volumetric efficiency, and motor efficiency. It has a great effect on improving the efficiency of compressor systems and the reliability of compression mechanisms and electric motors.

Effects of the Invention As is clear from the above-described configuration, the present invention has the following features: a pre-cooling pipe whose both ends are opened to the outside of a closed container, a part of which is interrupted to connect an expansion chamber, a communication hole is provided in a part of this expansion chamber, and a communication hole is provided in a part of this expansion chamber. Since the expansion chamber, including the communication hole, is partially submerged under the surface of the lubricating oil, the relatively low temperature of the lubricating oil that is filled inside the expansion chamber is Direct cooling can be performed by the refrigerant of It is extremely useful in practical terms.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of a conventional compressor, and Figure 2 is a
Figure 3 is a refrigeration cycle piping diagram, Figure 4 is a sectional view of IA-A.
The figure is a longitudinal cross-sectional view of a compressor showing an embodiment of the present invention, FIG. 5 is a cross-sectional view along the line B-B, and FIG.
FIG. 7 is a refrigeration cycle piping diagram. 2...Rotary compression mechanism, 3...Electric motor, 4...
... airtight container, 13 ... lubricating oil, 14.14
'... Pre-cooling pipe, 14G... Expansion chamber, 1
4d'...Communication hole. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure i Male 2 Figure 3 Figure 1ρ / Figure 4 Figure 5 Page 6 Figure 7 Figure 8 /14!

Claims (1)

[Claims] an electric motor in a closed container, a rotary compression mechanism driven by the electric motor, lubricating oil for lubricating the rotary compression mechanism, a pre-cooling pipe with both ends open outside the closed container, and an expansion chamber connected to the pre-cooling pipe. A rotary type, comprising a communication hole in a part of the wall of the expansion chamber, and a part of the expansion chamber including the communication hole is immersed under the surface of the lubricating oil.