JPS597038B2 - Cooling structure of rotary compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling device for a hermetic rotary compressor, and one of its objects is to effectively cool a compression mechanism and improve compressor performance. be.

Conventionally, as shown in FIG. 2, a cooling device for a compression mechanism introduces discharged refrigerant gas to the outside of a closed container a, cools the discharged refrigerant gas in a preliminary heat exchanger b, and then returns the discharged refrigerant gas to the outside of a closed container a.
There is an intermediate cooling method that returns the

However, in this intercooling method, a large amount of discharged refrigerant passes through the preliminary heat exchanger b in a short period of time, so that the refrigerant that returns into the closed container a is mostly dry vapor and does not become liquid refrigerant.

Since this dry steam hardly cools the lubricating oil around the compression mechanism C, the cooling effect of the compression mechanism C cannot be obtained.

In addition, if the return gas contains liquid by increasing the size of the preheat exchanger b, not only will the entire compressor become larger, but the liquid refrigerant will enter the lubricating oil and heat up. Since the lubricating oil is cooled by evaporation, the cooling effect of the compression mechanism C can be obtained, but the lubricating oil foams due to the evaporation of the liquid refrigerant, and the refrigerant gas of the liquid refrigerant is sucked through the lubricating oil suction port d. , which has the disadvantage of inhibiting lubrication.

In addition, as another cooling method, as shown in Fig. 3, a compressor e
In a refrigeration cycle in which a condenser f, a capillary tube g, and an evaporator h are connected in a ring, there is an injection method in which high-pressure liquefied refrigerant is drawn out from the condenser f and the liquefied refrigerant is directly injected into the cylinder i. .

In this injection method, although the effect of directly supplying refrigerant to the compression mechanism j can be obtained, there is a wasteful compression process in which the injected refrigerant is compressed again, so the efficiency of the compressor decreases.

Therefore, the present invention solves the drawbacks of the conventional compressor cooling device described above, and has a structure in which the liquid refrigerant always returns to the compressor, and a gas-liquid separation passageway that guides the lubricating oil to the compression mechanism. By providing this, a small cooling device is provided which efficiently cools the compression mechanism and improves the performance of the compressor without sacrificing the lubrication effect.

Hereinafter, reference will be made to FIG. 1 of the accompanying drawings showing one embodiment of the present invention.

In the figure, reference numeral 1 denotes a closed container, in which a stator 2 and a rotor 3 of the electric motor section are arranged above the container, and below it,
A compression mechanism 4 that rotates with power from the electric motor is provided.

Reference numeral 5 denotes a passage whose upper opening is above the oil surface of the lubricating oil reservoir 1a of the closed container 1 and at a position away from the lubricating oil suction port 6, for sucking lubricating oil for lubricating the compression mechanism 4, etc. It is.

This passage 5 surrounds the vicinity of the lubricating oil inlet 6 and has a plurality of small holes 8 communicating with the lubricating oil reservoir 7, and is configured so as not to directly suck the lubricating oil below the lubricating oil reservoir 7. , performs gas-liquid separation action in lubricating oil.

Reference numeral 9 denotes a radiator provided outside the hermetic container 1, with both ends opening toward the space between the lower part of the electric motor inside the hermetic container 1 and the lubricating oil surface. Falling part 9a
The amount of heat dissipated from the rising part 9 is increased by providing a large number of fins.
I chose it as a dog because of the amount of heat dissipated in b.

The falling portion 9a opens below the opening position of the rising portion 9b.

This radiator 9 forms a refrigerant passage parallel to the passage in the closed container 1 of the refrigerant discharged from the rotary compression mechanism.

The rotary compressor having the above configuration constitutes a well-known refrigeration cycle in which the discharge pipe 10 passes through the condenser 11, the expansion valve 12, and the evaporator 13, and returns to the compressor.

Therefore, the discharged refrigerant gas discharged from the compression mechanism 4 passes through the discharge pipe 10 from inside the closed container 1, passes through the condenser 11, the expansion valve 12, and the evaporator 13, and is sucked into the compression mechanism 4 again.

Further, some of the refrigerant accumulates in the radiator 9.

The refrigerant is cooled and liquefied in the falling portion 9a of the heat exchanger 9 with a high amount of heat dissipation, and drips into the space surrounded by the compression mechanism 4 and the closed container 1, instantly dissipating the lubricating oil in the space. It is directly cooled by removing latent heat of vaporization, and then poured into the closed container 1 again.

This liquid refrigerant has a higher specific gravity than the lubricating oil, so it sinks to the bottom of the lubricating oil reservoir, foams, becomes a gas, rises through the lubricating oil again, and pops out from the oil tank. Since the foamed gas is separated by the passage 5 so as not to be directly sucked into the lubricating oil suction port 6, the lubrication effect is prevented from being inhibited by the foaming of the liquid refrigerant.

In addition, since the lubricating oil is efficiently cooled by the liquefied refrigerant, the compression mechanism 4 is inevitably cooled, which has the effect of bringing the refrigerant closer to the most efficient isothermal compression, reducing the amount of work required to compress the refrigerant gas. do.

Moreover, by cooling the compression mechanism 4, the weight of refrigerant sucked is increased, and an increase in cooling capacity is expected, and the lubricating oil itself is prevented from becoming high temperature, thereby providing stable lubricating performance.

As described above, the cooling device for a rotary compressor of the present invention includes an electric motor disposed above an airtight container, and a rotary compression mechanism driven by the electric motor disposed below. a rotary compressor on which discharged refrigerant gas acts; a lubricating oil reservoir in which the rotary compression mechanism is immersed in a lower part of the closed container, and one end connected to a lubricating oil inlet of the rotary compression mechanism; A gas-liquid separation passageway is provided, the other end of which opens at a position above the lubricant level of the lubricant oil reservoir and away from the lubricant suction port, and the lubricant oil is placed at appropriate locations in this gas-liquid separation passageway. A small hole is provided for the reservoir lubricating oil to flow in, and both ends are opened outside the sealed container between the lubricating oil and the electric motor, and a passageway in the sealed container is provided for the refrigerant discharged from the rotary compression mechanism. A radiator is provided that forms a refrigerant passage in parallel with the airtight container, and the amount of heat radiated is composed of a rising portion extending upwardly of the sealed container and a falling portion returning from the tip of this rising portion into the sealed container. A large number of heat dissipation fins are installed on the descending part.The discharge refrigerant gas accumulated in the radiator is cooled by the radiator, and in order to reliably create liquid refrigerant and cool the compression mechanism, the compression work of the compressor is reduced. This makes it possible to reduce the amount of heat dissipated, reduce the size of the radiator, improve compression performance, increase the amount of refrigerant suction, and prevent deterioration of lubricating oil due to high temperatures. Since the gas-liquid separation effect of the medium is performed, the suction effect of the lubricating oil is smooth, and since the gas-liquid separation passage is opened at a position above the lubricating oil level and away from the lubricating oil suction port, foaming can be prevented. Inhalation of refrigerant can be prevented, and the small holes provided in the gas-liquid separation passage can reliably inhale lubricating oil even if the oil level moves up and down due to foaming of the refrigerant or vibration of the compressor. It has various advantages, such as that the lubricating action is not inhibited.

[Brief explanation of the drawing]

Fig. 1 is a diagram of a refrigeration cycle equipped with a cooling device for a rotary compressor according to an embodiment of the present invention, Fig. 2 is a sectional view of a compressor showing a conventional example, and Fig. 3 shows yet another conventional example. It is a refrigeration cycle diagram. 1...Airtight container, 2...Stator, 3.
...Rotor, 4...Compression mechanism, 5...
... Passage (gas-liquid separation passage), 7 ... Lubricating oil reservoir, 8 ... Small hole, 9 ... Heat radiator, 9
a... Falling part, 9b... Rising part.

Claims (1)

[Claims] 1. A rotary compressor is configured in which a discharged refrigerant gas acts in the closed container by disposing an electric motor above the closed container and a rotary compression mechanism driven by the electric motor below, and a lubricating oil reservoir in which the rotary compression mechanism is immersed in a lower part of the closed container; one end is connected to the lubricating oil inlet of the rotary compression mechanism; the other end is above the lubricating oil surface of the lubricating oil reservoir; , and a gas-liquid separation passage opened at a position remote from the lubricating oil inlet, and a small hole into which the lubricating oil in the lubricating oil reservoir flows is provided at an appropriate location in the gas-liquid separation passage, and the airtight container A radiator is provided on the outside, the ends of which are open between the lubricating oil level in the sealed container and the electric motor, and which forms a refrigerant passage parallel to the passage in the sealed container of the refrigerant discharged from the rotary compression mechanism. A rotary compressor comprising a rising part extending upward from a closed container and a falling part returning from the tip of the rising part into the sealed container, and a large number of radiating fins are provided on the falling part. Cooling system.