JPH022478B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compressor cooling device for cooling a compressor section of a hermetic rotary compressor.

Conventionally, as a means to prevent overheating of a compressor, a portion of liquid refrigerant in a refrigeration cycle is introduced into the cylinder of the compressor, and the compressor is cooled by the latent heat of vaporization of the liquid refrigerant. A so-called injection cooling system is known. FIG. 1 shows a refrigeration cycle equipped with an injection circuit, and is constructed by sequentially connecting a compressor, a condenser 2, a capillary tube 3 serving as a pressure reducing device, and an evaporator 4 in an annular manner. Furthermore, injection circuit A
is constructed by branching an injection introduction pipe 6 from between the condenser 3 and the capillary tube 4 and connecting it to the compressor 1.

Next, the structure of a compressor equipped with a conventional injection mechanism will be explained with reference to FIG.

In the figure, the injection introduction pipe 6 is
It is disposed near a discharge port (not shown) of a cylinder body a constituting the compressor section of the compressor 1, and communicates with a cylinder high pressure chamber c via an opening b formed in the cylinder body a.

Then, the injection refrigerant is injected into the cylinder high pressure chamber c from this opening b to mix the refrigerant gas in the cylinder which is in the middle of compression with the liquid refrigerant having a small enthalpy, thereby lowering the temperature of the refrigerant gas to be discharged. Cools the entire compressor.

Generally, this type of rotary compressor is called a high-pressure type, and has a structure in which compressed refrigerant gas is once discharged into the internal space e of the closed container d, and then discharged outside the compressor 1. Therefore, in this type of rotary compressor, the temperature of the refrigerant gas in the internal space e becomes extremely high, and this heat heats the cylinder body a, which in turn causes the temperature of the refrigerant gas in the cylinder low pressure chamber f, which is in the middle of suction, to become extremely high. This method has the drawback of heating the refrigerant gas, resulting in a decrease in suction volume, and a decrease in volumetric efficiency and coefficient of performance.

Therefore, a compressor equipped with an injection mechanism that injects refrigerant into the cylinder has the effect of lowering the temperature of the discharged refrigerant, so the temperature of the cylinder body a also decreases slightly, reducing the heating of the refrigerant gas in the cylinder. Although a slight improvement in volumetric efficiency can be seen due to this, since it is indirect heating prevention, a large improvement in volumetric efficiency cannot be expected. In addition, in order to increase the cooling effect of the cylinder with a conventional injection mechanism, it is sufficient to inject a large amount of injection liquid refrigerant into the cylinder body a, but such means do not increase the compressor operation input,
This is impossible because it causes liquid compression and shortens the life strength of the compressor 1.

On the other hand, as a means of preventing overheating of the compressor,
The liquid refrigerant in the refrigerant cycle was made to flow into a pipe disposed in the oil in the closed container of the compressor, so that the oil was cooled by the latent heat of vaporization of the liquid refrigerant. A so-called oil cooler system is known.

Figure 3 shows a refrigeration cycle equipped with an oil cooler, which includes a compressor 1, a first condenser 2a, an oil cooler g for exchanging heat between the condensed refrigerant and lubricating oil, a second condenser 2b, and a pressure reducing device. capillary tube 3,
It is constructed by sequentially connecting evaporators 4 in an annular manner.

Next, the structure of a compressor equipped with an oil cooler mechanism will be explained.

In FIG. 3, refrigerant gas discharged from the compressor 1 is condensed into a liquid refrigerant in a first condenser 2a.
This liquid refrigerant is led to an oil cooler g provided in the oil reservoir of the compressor, where it is evaporated by the high-temperature lubricating oil, and its latent heat of vaporization lowers the temperature of the lubricating oil. The evaporated refrigerant is returned to the second condenser 2b,
It is recondensed and then passed through the capillary tube 4 to the compressor 1 again.
Return to

In general, compressors equipped with an oil cooler mechanism have the effect of lowering the temperature of the lubricating oil, so the temperature of the cylinder body also decreases slightly, and there is also a slight improvement in volumetric efficiency due to less heating of the refrigerant gas in the cylinder. Similar to the injection mechanism, this method also indirectly prevents heating, so it cannot be expected to significantly improve volumetric efficiency.

The present invention eliminates the drawbacks of the conventional injection mechanism and oil cooler mechanism, has a simple structure, uses liquid refrigerant, strengthens the cooling effect of the cylinder body, improves the coefficient of performance of the compressor, and extends the life strength of the compressor. It is something that increases.

Hereinafter, the present invention will be explained with reference to FIGS. 4 to 7 of the accompanying drawings showing one embodiment thereof.

In the figure, reference numeral 7 denotes a closed container constituting the compressor 1, and as is well known, an electric motor section (not shown) and a compressor section 8 driven by the electric motor section are disposed inside the container. . The compressor section 8 includes a cylinder body 10 forming a cylindrical cylinder 9.
and a roller 1 disposed inside the cylinder 9.
1, a crankshaft 12 having an eccentric portion, and a crankshaft 12 disposed on both end surfaces 10a, 10b of the cylinder body 10, so that the roller 11 and the crankshaft 12 are connected from both upper and lower sides of the cylinder 9. End plate 1 supported so as to be able to rotate and slide along the inner wall
3 and 14. Here, each of the end plates 13 and 14 also serves as a bearing. 15
is a blade that partitions the cylinder 9 into a low pressure chamber 5a and a high pressure chamber 5b in the cylinder body 10,
It is constantly pressed against the roller 11 by the spring 16. The lower end plate 14 has a first insertion hole 14b located near the suction port 17 of the cylinder 9.
and the end surface 1 of the end plate 14 from this first insertion hole 14b.
4a, and a refrigerant introduction pipe 18 for introducing liquid refrigerant in the refrigeration cycle is fitted into the first insertion hole 14b of the end plate 14. Also, in the vicinity of the discharge port 19 of the cylinder 9, there is a second insertion hole 14d.
and the end surface 1 of the end plate 14 from this second insertion hole 14d.
4a, and a refrigerant discharge pipe 20 for returning refrigerant evaporated during the refrigerant cycle is fitted into the second insertion hole 14d of the end plate 14. 21 is the cylinder body 1
An annular groove of an appropriate depth is formed on one end surface 10a of 0 in a substantially annular shape avoiding the blade 15, and one end thereof is a first communication hole 1 formed in the lower end plate 14.
4c and the first insertion hole 14b, the refrigerant introduction pipe 1
8, and the other end communicates with the refrigerant discharge pipe 20 via a second communication hole 14e and a second insertion hole 14d formed in the lower end plate 14. Here the second
Since the communication hole 14e is formed near the discharge pipe 19, the annular groove 21 extends almost 360 degrees along the inner wall of the cylinder 9, sandwiching the blade 15 therebetween.

In the above configuration, when the compressor 1 is operated, the return refrigerant in the refrigeration cycle flows into the cylinder 9 through the suction port 17. The refrigerant that has flowed in is surrounded by the inner wall of the cylinder 9, the roller 11, the blade 15, and both end plates 13 and 14, and the roller 1
1 is compressed as it rotates along the eccentric portion of the crankshaft 12. After the compressed refrigerant is condensed in the first condenser 2a, it flows from the refrigerant introduction pipe 18 to the first communication hole 14c of the lower end plate 14, and then flows into the annular groove 21 provided in the one end surface 10a of the cylinder body 10. Inflow. Since the liquid refrigerant that has flowed in here evaporates due to the heat generated by compression, the latent heat during evaporation causes the cylinder body 10 to
The cylinder body 10 is efficiently cooled over a wide range from the vicinity of the suction port 17 to the vicinity of the discharge port. Then, the gasified refrigerant is transferred to the lower end plate 14.
The refrigerant is sent to the refrigerant discharge pipe 20 through the second communication hole 14e, and is subsequently connected to the second condenser 2b, capillary tube 3, and evaporator 4.
It is then circulated to the compressor 1 again.

Therefore, due to the liquid refrigerant, the cylinder body 10
Since the refrigerant is cooled from the vicinity of the suction port 17, the temperature of the suction refrigerant can be significantly lowered compared to the conventional method, thereby greatly improving the volumetric efficiency. Moreover, due to this, it is possible to lower the input during compressor operation, and at the same time, it is possible to improve the refrigerating capacity and the coefficient of performance. In addition, since the liquid refrigerant is not directly introduced into the cylinder, no liquid compression occurs, and since the cylinder body 10 is cooled over a wide area, the compressor 1
can increase the life strength of

It goes without saying that this effect increases as the annular groove 21 approaches the inner wall of the cylinder 9. Further, the annular groove 21 is not limited to the cylinder body 10 side, but may be formed across the lower end plate 14 or both, and the same effect as in the previous embodiment can be obtained.

As is clear from the above embodiments, the cooling device for a closed rotary compressor according to the present invention includes a cylinder body forming a cylindrical cylinder in a closed container;
A compressor section is provided, each of which includes an end plate that closes both end surfaces of the cylinder body and supports a crankshaft, and a roller and a blade that are disposed within the cylinder body and perform suction and compression of refrigerant; The compressor section is provided with a refrigerant introduction pipe extending from the outside of the hermetic container toward the crankshaft and a refrigerant discharge pipe extending from the crankshaft toward the outside of the hermetic container, and further provided with the cylinder body. and an overlapping surface of the end plate, one side communicating with the liquid refrigerant introduction pipe, avoiding a blade sliding on the cylinder body,
The other is provided with an annular groove that communicates with the gas refrigerant discharge pipe, and the high-pressure refrigerant in the refrigeration cycle flows into the refrigerant introduction pipe, the annular groove, and the refrigerant discharge pipe,
As in the past, a part of the high-pressure liquid refrigerant is injected into the compression space of the cylinder to perform injection cooling, and the high-pressure liquid refrigerant is guided to an oil cooler installed in an oil reservoir in a sealed container to control the temperature of the lubricating oil. Compared to mechanisms that lower the air pressure, the cylinder body is directly cooled by high-pressure liquid refrigerant and no liquid compression occurs, resulting in improvements in volumetric efficiency, coefficient of performance, and compressor life.

In addition, by forming the annular groove close to the inner wall of the cylinder body, the above-mentioned cooling effect of the cylinder body is further improved, so the performance of the compressor can be further improved. It is something.

[Brief explanation of drawings]

Figure 1 is a refrigeration circuit diagram equipped with a conventional injection cooling mechanism, Figure 2 is a cross-sectional view of a hermetic rotary compressor equipped with the same injection cooling mechanism, and Figure 3 is a refrigeration circuit diagram equipped with a conventional oil cooler mechanism. A refrigeration circuit diagram, FIG. 4 is a sectional view of a main part of a hermetic rotary compressor equipped with a cooling device according to an embodiment of the present invention, FIG. 5 is a sectional view taken along line A-A in FIG. 4, and FIG. The figure is a sectional view taken along the line B-B in FIG. 4, and FIG. 7 is a refrigeration circuit diagram equipped with the same cooling mechanism. 1...Compressor, 7...Airtight container, 8...Compressor section, 9...Cylinder, 10...Cylinder body, 1
1...Roller, 12...Crankshaft, 13, 14
... end plate, 15 ... blade, 18 ... refrigerant introduction pipe, 20 ... refrigerant discharge pipe, 21 ... annular groove.

Claims (1)

[Scope of Claims] 1. A cylinder body that forms a cylindrical cylinder in a closed container, an end plate that closes both end surfaces of the cylinder body and supports a crankshaft, and a cylinder that is disposed within the cylinder body. A compressor section is provided which is equipped with a roller and a blade, respectively, for suctioning and compressing refrigerant, and the compressor section is provided with a refrigerant introduction pipe extending from the outside of the closed container toward the crankshaft, and a refrigerant introduction pipe extending from the crankshaft from the outside of the closed container. A refrigerant discharge pipe extending outward from the airtight container is disposed, and one side is arranged to introduce the refrigerant into the overlapping surface of the end face of the cylinder body and the end plate, avoiding a blade that slides on the cylinder body. Cooling of a hermetic rotary compressor, which is provided with an annular groove that communicates with the refrigerant pipe and the other end communicates with the refrigerant discharge pipe, and allows high-pressure refrigerant in a refrigeration cycle to flow through the refrigerant introduction pipe, the annular groove, and the refrigerant discharge pipe. Device. 2. The cooling device for a hermetic rotary compressor according to claim 1, wherein the annular groove is formed close to the inner wall of the cylinder body.