JPH08193588A - Motor-driven compressor - Google Patents

Abstract

PURPOSE: To prevent increase of the oil discharge amount from a compressor to a refrigerating cycle even though the compressor is in high speed operation by furnishing a discharge pipe over the space opposite the compressor mechanism part while a motor in an enclosed vessel is interposed. CONSTITUTION: An enclosed vessel 1 is installed approx. horizontally and accommodates a compression mechanism part 9, a motor 6 to drive the mechanism part 9, and a crankshaft 10 to transmit the torque of the motor 6 to the part 9. The vessel 1 is formed as a high pressure type shell where a high pressure refrigerant gas compressed by the part 9 acts, and a discharge pipe 5 is installed over the space opposite the part 9 while the motor 6 is interposed. Thereby the discharge pipe 5 is positioned within the vessel 1 remotely from the surface of the refrigerating machine oil, and it is unlikely to be influenced by oil drops spattering upon being agitated by a rotor, and the amount of oil splashing out of the compressor can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric compressor used for cooling and heating, or a cooling device such as a refrigerator.

[0002]

2. Description of the Related Art Conventionally, electric compressors such as rotary compressors and scroll compressors have been used as cooling devices for cooling and heating, or refrigerators.

A compressor of this type is shown in FIG.
2689). As shown in FIG.
A compression mechanism unit 102, a stator 104 that constitutes the electric motor 103, a rotor 105, and a crankshaft 106 that transmits the rotation of the electric motor 103 to the compression mechanism unit 102 are provided inside. Further, the end plate of the closed casing 101 is provided with a suction pipe 107 for sucking the low pressure refrigerant gas and a discharge pipe 108 for discharging the high pressure refrigerant gas.

In the above structure, when the rotor 105 constituting the electric motor 103 rotates, this rotation causes the crankshaft 1 to rotate.
It is transmitted to the compression mechanism section 102 by 06. When the compression mechanism 102 rotates and a compression action occurs, the suction pipe 10
The low-pressure refrigerant gas sucked from 7 is pressurized to a high-pressure refrigerant gas by the compression mechanism section 102, and the hermetically sealed container 101
It is exhaled inside. After this, this high-pressure refrigerant gas passes through the gap of the electric motor 103 to cool the stator 104 and the rotor 105, and is then discharged from the discharge pipe 108 to a refrigeration cycle (not shown).

In such a compressor, during normal operation, oil is mixed into the refrigerant gas being compressed in order to seal the gap of the compression mechanism section 102 and increase the compression efficiency. Further, in some cases, the lubricating oil is agitated by the rotor 105 of the electric motor to form droplets, and the closed container 1
It is scattered within 01.

[0006]

The high-pressure refrigerant gas discharged from the compression mechanism portion 102 into the closed container 101 further captures oil droplets, and a large amount of oil is discharged from the discharge pipe 108 to the refrigeration cycle. I will go away. In particular, when the number of refrigerant discharges is increased by increasing the number of rotations of the compressor, the oil discharge rate (weight of oil discharge / weight of refrigerant discharge) is significantly increased.

As the amount of oil discharged from the compressor to the refrigeration cycle increases (when the oil discharge rate exceeds about 0.3%), the pipe pressure loss in the refrigeration cycle increases and the condenser, Since the heat exchange efficiency in a heat exchanger such as an evaporator decreases, the refrigerating capacity does not increase even if the rotation speed of the compressor is increased, or the coefficient of performance of the refrigeration cycle decreases. It was

Therefore, an object of the present invention is to provide a compressor in which the amount of oil discharged from the compressor to the refrigeration cycle does not increase even when the compressor is operated at a high rotational speed.

[0009]

In order to solve the problems, the first aspect of the present invention is to provide a discharge pipe above a space on the opposite side of the compression mechanism part with the electric motor in the closed container interposed therebetween. .

Further, as a second means, a discharge pipe is provided above the space on the opposite side of the compression mechanism part with the electric motor in the closed container interposed therebetween, and an oil separator constituted by alternately combining a plurality of plates. Is provided below the discharge pipe.

Further, as a third means, the surface of a plurality of plates constituting the oil separator provided below the discharge pipe is coated with an oil-repellent material enclosed in the airtight container.

Further, as a fourth means, an oil separator is provided in which a discharge pipe is provided above the space on the opposite side of the compression mechanism section with the electric motor in the closed container interposed therebetween, and a plurality of plates are alternately combined. Is provided below the discharge pipe, and a wire mesh is installed near the outlet of the oil separator so as to cover the inlet of the discharge pipe.

Further, as a fifth means, a refrigerating machine oil that is incompatible with the refrigerant to be used is used and is combined with any one of the first to fourth means.

[0014]

The operation of the above means is as described below.

According to the first means, the discharge pipe is far away from the liquid surface of the refrigerating machine oil in the hermetically sealed container, so that it is less affected by the oil droplets agitated and scattered by the rotor, and the compressor is The amount of oil that jumps out of is suppressed.

According to the second means, since the oil separator constituted by alternately combining a plurality of plates is provided below the discharge pipe, the refrigerant gas containing a large amount of oil can be used in a plurality of plates. These plates come into contact with each other while passing through the bent gas passage constituted by the above, and at this time, oil adheres to the surfaces of the plates and is separated from the refrigerant gas.

According to the third means, since the surface of the plurality of plates constituting the separator is coated with the oil-repellent material, the oil adhered to the surface of the plates immediately becomes spherical. As they collect, the particles grow and run down, the separation of oil from the refrigerant gas is promoted.

According to the fourth means, since the wire mesh is installed near the outlet of the oil separator so as to cover the inlet of the discharge pipe,
The oil that has not been separated when passing through the gas passage collides with the metal mesh together with the refrigerant and is captured there, and the amount of oil that jumps out of the compressor is further suppressed.

According to the fifth means, since the oil that is incompatible with the refrigerant is used, once the oil jumps out from the compressor to the refrigeration cycle, the refrigerant and the oil do not mix, so that evaporation occurs. In a low pressure region such as a vessel, the viscosity of the oil becomes high and it becomes difficult to return to the compressor. However, since it is combined with any one of the above first to fourth means, especially in an incompatible system, these The oil discharge reducing means becomes effective.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In the figure, 1 is a closed container, 2 and 3 are end plates of the closed container,
Reference numeral 4 is a suction pipe, and 5 is a discharge pipe. 6 is an electric motor, 7 is a stator of the electric motor, 8 is a rotor of the electric motor, and 9 is a compression mechanism portion. Reference numeral 10 is a crankshaft that transmits the rotational force of the electric motor to the compression mechanism section 9. Since the present embodiment is a scroll compressor, the compression mechanism section 9 is composed of an orbiting scroll 11, a fixed scroll 12, an orbiting bearing 13, a bearing component 14, and the like. The bearing component 14 supports the large shaft portion 15 of the crankshaft 10. A partition member 16 is fixed to the closed container 1 and divides the closed container 1 into a space where the compression mechanism portion 9 exists and a space where the discharge pipe 5 exists.

A second bearing 17 for supporting one end of the crankshaft 10 is attached to the center of the partition member 16. Further, the partition member 16 is provided with a plurality of gas ejection holes 18 through which the refrigerant gas passes. And this gas ejection hole 1
A gas collision plate 19 is provided at a position opposed to 8. 20
Is an oil pump that supplies oil 27 to the sliding portion of the compression mechanism portion 9, and extends the suction plate provided with the suction port of the oil pump 20 to form the gas collision plate 19. Reference numeral 21 denotes an oil separator provided below the discharge pipe 5, and a plurality of plates 22 are alternately combined to form a gas passage. Reference numeral 23 is a wire mesh provided so as to cover the inlet of the discharge pipe 5.

Next, the operation of the scroll compressor having such a structure will be described. As the electric motor rotor 8 rotates, the crankshaft 10 and the orbiting bearing 13 rotate, and as a result, the orbiting scroll 11 orbits around the fixed scroll 12, and the orbiting scroll 11 and the fixed scroll 1 rotate.
A compression effect occurs in the space of 2. Then, low-pressure refrigerant gas is sucked from the suction pipe 4, compressed in the space between the orbiting scroll 11 and the fixed scroll 12, and discharged from the discharge hole 24 into the closed container 1. In order to seal the gap between both scrolls and improve compression efficiency, oil is mixed with the refrigerant gas being compressed, so the discharged high-pressure refrigerant gas contains a certain amount of oil. After that, the high-pressure refrigerant gas passes through the gas passage 25 provided in the compression mechanism section 9 and the gas passage 26 provided in the electric motor stator 7, and reaches the space sandwiched between the stator 7 and the partition member 16. Since a large amount of oil droplets wound up by the electric motor rotor 8 are scattered in this space, the refrigerant gas captures these oil droplets and contains a large amount of oil.

After this, the refrigerant gas containing a large amount of oil blows out as a jet from the gas ejection holes 16 formed in the partition member 16 and collides with the gas collision plate 19. The refrigerant gas that collides with the gas collision plate 19 at high speed adheres to this plate and flows, so that the gas and the plate are in contact with each other for a long time.
During this contact, the oil contained in the refrigerant gas sequentially adheres to the collision plate 19, and the adhered oil grows and drops into larger oil droplets on the gas collision plate 19 due to its surface tension. By such collision separation, oil is first separated from the refrigerant gas.

The discharge interval 5 is attached to the upper part of the end plate 3, which increases the distance from the oil level, and reduces the effect of removing the oil droplets generated by the stirring by the rotor 8, and There is also an effect that the oil separator 21 can be easily installed below the discharge pipe 5.

Before entering the discharge pipe 5, the refrigerant gas circulates around the oil separator 21 and enters the oil separator 21 from its lower portion. Inside the oil separator 21, the plates 22 are alternately combined to form a refrigerant passage, so that the refrigerant gas passes through the refrigerant passage with twists and turns. At this time, since the refrigerant gas flows while contacting the surface of the plate 22, the oil contained in the refrigerant gas adheres to the surface and is removed.

Further, since the surface of the plate 22 is subjected to a surface treatment for repelling oil, for example, PTFE treatment, the oil is absorbed by the plate 2
As soon as it adheres to the surface of 2, the oil becomes granular due to its surface tension and quickly flows down, and as a result, the separation of the oil is promoted.

The wire mesh 2 is provided near the outlet of the oil separator 21.
Although 3 is installed so as to cover the discharge pipe 5, the oil which has not fallen by the collision separation and the contact separation is separated by the refrigerant gas passing through the wire net 23.

When an HFC refrigerant that does not destroy the ozone layer (such as a mixed refrigerant of R32 / R125 / R134a) is used and an oil that is incompatible with the HFC refrigerant, such as mineral oil or alkylbenzene, is used as the refrigerating machine oil. In addition, once the oil goes out to the refrigeration cycle, the refrigerant and the oil do not melt in the low pressure part such as the evaporator, so that the viscosity of the oil remains high and the oil does not return to the compressor. If the oil returns to the compressor poorly, the liquid level in the compressor may decrease, causing problems such as wear. When such an incompatible refrigerant / oil is used, installing the discharge pipe 5, the oil separator 21, and the wire mesh 23 as described above can suppress the oil discharge from the compressor, and A great effect can be obtained in terms of ensuring the reliability of the machine.

[0030]

According to the present invention, the following effects can be obtained. In the closed container, the discharge pipe is far away from the liquid surface of the refrigerating machine oil, so that it is less affected by the oil droplets that are stirred and scattered by the rotor, and the amount of oil that jumps out from the compressor to the refrigeration cycle is suppressed.

Furthermore, since an oil separator constituted by alternately combining a plurality of plates is provided below the discharge pipe,
The oil adheres to the surface of the plates in the oil separator and is effectively separated from the refrigerant gas.

Further, since the surface of the plurality of plates constituting the separator is coated with the oil-repellent material, the oil adhered to the surface of the plates immediately becomes spherical and collects, and the particles become large. As it flows down, it promotes the separation of oil from the refrigerant gas.

Further, since the wire net is installed near the outlet of the oil separator so as to cover the inlet of the discharge pipe, the oil which is not separated when passing through the gas passage collides with the wire net and collides with it. The amount of oil that is captured and jumps out of the compressor is further reduced.

When oil that is incompatible with the refrigerant is used, the oil is prevented from splashing out of the compressor into the refrigeration cycle, so that a great effect is obtained especially in terms of ensuring the reliability of the compressor.

[Brief description of drawings]

FIG. 1 is a sectional view of a scroll compressor showing an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional scroll compressor.

[Explanation of symbols]

 1 Airtight Container 5 Discharge Pipe 6 Electric Motor 9 Compression Mechanism 10 Crank Shaft 21 Oil Separator 23 Wire Mesh 27 Oil

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Shin, 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A hermetically sealed container provided with a compression mechanism portion, an electric motor for driving the compression mechanism portion, and a crankshaft for transmitting the rotational force of the electric motor to the compression mechanism portion in a hermetically sealed container which is installed substantially horizontally. The container is a high-pressure shell on which high-pressure refrigerant gas compressed by the compression mechanism acts, and a discharge pipe is provided above the space on the opposite side of the compression mechanism with the electric motor in the closed container. Become an electric compressor. 2. A hermetically sealed container provided substantially horizontally, comprising a compression mechanism section, an electric motor for driving the compression mechanism section, and a crankshaft for transmitting the rotational force of the electric motor to the compression mechanism section. The container is a high-pressure shell on which the high-pressure refrigerant gas compressed in the compression mechanism acts, and a discharge pipe is provided above the space on the opposite side of the compression mechanism with the electric motor in the closed container, An electric compressor in which an oil separator configured by alternately combining a plurality of plates is provided below the discharge pipe. 3. The electric motor according to claim 2, wherein the surface of a plurality of plates constituting an oil separator provided below the discharge pipe is coated with a material repelling refrigerating machine oil enclosed in a closed container. Compressor. 4. A hermetically sealed container provided substantially horizontally, comprising a compression mechanism section, an electric motor for driving the compression mechanism section, and a crankshaft for transmitting the rotational force of the electric motor to the compression mechanism section. The container is a high-pressure shell on which the high-pressure refrigerant gas compressed by the compression mechanism acts, and a discharge pipe is provided above the space on the opposite side of the compression mechanism with the electric motor in the closed container. An electric compressor in which an oil separator configured by alternately combining a plurality of plates is provided below the discharge pipe, and a wire mesh is installed near the outlet of the oil separator so as to cover the inlet of the discharge pipe. 5. A refrigerating machine oil to be enclosed in a compressor, wherein an oil that is incompatible with the refrigerant used is used.
Alternatively, the electric compressor according to item 4.