JPH109180A - Hermetic scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of liquid compression by preventing the flow of a liquid mixture of a liquid refrigerant and a lubricating oil into a compression-enclosed chamber, and to configure a compressor such as a spiral wound body or a bearing by liquid compression. Provided is a scroll compressor having high durability by preventing damage to members and seizure. A closed housing is partitioned into a discharge chamber and a low-pressure side by a discharge cover, and a scroll compression mechanism is arranged on the low-pressure side. Discharge gas from a discharge port of the scroll housing is discharged through the discharge path of the discharge cover. A hermetic scroll compressor that discharges to a discharge chamber and discharges from a discharge pipe connected to the discharge chamber to the outside, and has a through hole that communicates with the inside of the discharge chamber and the low pressure side at a lower position of the discharge cover. Set up
The through hole is provided with an on-off valve that closes the through hole at the discharge pressure during operation and opens when the compressor is stopped, and prevents the flow of the liquid refrigerant from the discharge chamber into the closed housing during the compressor operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal hermetic scroll compressor used for an air conditioner.

[0002]

FIG. 4 is a system diagram of the air conditioner during cooling of a refrigeration cycle. In FIG. 4, a high-temperature, high-pressure gas refrigerant pressurized by a compressor 100 enters a condenser 88 through a discharge pipe 87, where it is cooled and condensed and liquefied, and a refrigerant liquid pipe 90 is formed.
From 1 enters the expansion valve 89. The refrigerant which has been adiabatically expanded by the expansion valve 89 to be in a low-pressure gas-liquid two-phase state exchanges heat with the indoor air in the evaporator 90 to cool it, and also evaporates and vaporizes, and passes through the suction pipe 82. It is sucked into the compressor 1.

FIG. 3 shows an example of the compressor 100. The compressor 100 is a horizontal hermetic scroll compressor. In FIG. 3, a scroll compression mechanism C is provided on the right inside the barrel-shaped hermetic housing 8 installed horizontally.
An electric motor M is incorporated on the left side.

The scroll compression mechanism C allows the fixed scroll 1, the orbiting scroll 2, and the orbiting scroll 2 to revolve and revolve, but the rotation preventing mechanism 3, such as an Oldham ring, for preventing the revolving rotation, the rotating shaft 5, and the like. It comprises a main bearing 71 and a sub-bearing 72 that support the rotary shaft 5, a orbiting bearing 73 and a thrust bearing 74 that support the orbiting scroll 2, and the like.

The fixed scroll 1 includes an end plate 11 and a spiral body 12 erected on the inner surface of the end plate 11, and the end plate 11 is provided with a discharge port 13.

The orbiting scroll 2 has an end plate 21 and a spiral body 22 erected on the inner surface of the end plate 21, and a drive bush 25 is provided with a drive bush 25 in a boss 23 erected on the outer surface of the end plate 21. And is rotatably fitted through the connector.

An eccentric pin 53 projecting from the right end of the rotary shaft 5 is rotatably fitted into an eccentric hole formed in the drive bush 25.

The fixed scroll 1 and the orbiting scroll 2 are mutually eccentric by the orbital radius, and
A plurality of closed spaces 2 are symmetrically point-symmetric with respect to the center of the spiral by engaging at an angle shifted by 180 °.
4 will be formed.

Reference numeral 14 denotes a discharge chamber, 17 denotes a discharge valve for opening and closing between the discharge port 13 and the discharge chamber 14, and 15 denotes the discharge chamber 1 to which the discharge valve 17 is attached.
A discharge cover 151 for partitioning the discharge cover 4 from the bottom pressure side 81 in the housing 8, and a discharge passage 151 provided on the discharge cover 15 and opened and closed by a discharge valve 17.

In the horizontal hermetic scroll compressor constructed as described above, the refrigerant sucked from the suction pipe 82 is swirled while being compressed as the volume of the hermetically sealed space 24 is reduced by the orbital motion of the orbiting scroll 2. The discharge valve 17 is pushed open from the discharge port 13 to enter the discharge chamber 14, and is discharged to the condenser 88 through the discharge pipe 87.

In the horizontal hermetic scroll compressor described above, during operation, when the refrigerant dissolves in the lubricating oil accumulated in the discharge chamber 14 and the level of the lubricating oil reaches the level of the discharge port 13 or higher, The liquid leaks from the discharge valve 17, and the mixed liquid flows from the discharge port 13 into the closed space 24. When the compressor 1 is started in such a state, the liquid stored in the closed space 24 is compressed, so that a so-called liquid compression occurs. When such liquid compression occurs, the spirally wound bodies 12 and 22 forming the compression chamber 14 are damaged, resulting in poor compression. When the liquid compression occurs, an excessive load is applied to the bearing 23 and the like, and the occurrence of seizure of the bearing is observed.

SUMMARY OF THE INVENTION It is an object of the present invention to prevent a liquid mixture of a liquid refrigerant and a lubricating oil from flowing into a closed space for compression to prevent the occurrence of liquid compression, and to provide a compressor component such as a spiral wound body or a bearing by liquid compression. An object of the present invention is to provide a scroll compressor having high durability by preventing breakage and seizure of the scroll.

[0013]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems. The gist of the present invention is to separate the inside of a closed housing into a discharge chamber and a low-pressure side by a discharge cover, and to provide scroll compression to the low-pressure side. A hermetic scroll compressor having a mechanism, discharging discharge gas from a discharge port of the mechanism through the discharge path of the discharge cover to the discharge chamber, and discharging the gas to the outside through a discharge pipe connected to the discharge chamber. At the low position of the discharge cover, a through-hole communicating the inside of the discharge chamber and the low-pressure side is formed, and the through-hole is provided with an opening / closing valve that closes the through-hole with the discharge pressure during operation and opens when stopped. A hermetic scroll compressor characterized by the following.

[0014] Preferably, the on-off valve is constituted by a plate-shaped reed valve.

According to the above means, when the pressure in the discharge chamber and the pressure on the low pressure side in the closed housing are the same, such as when the compressor is stopped for a long time, the on-off valve 16 is opened and the through hole is opened. The liquid mixture of the liquid refrigerant and the lubricating oil that has been opened and accumulated in the discharge chamber is returned to the low pressure side, which is the suction side, and the liquid refrigerant does not accumulate in the discharge chamber.

When the compressor is started, the pressure on the low pressure side in the closed housing decreases and the pressure in the discharge chamber increases, so that the on-off valve closes the through hole due to this pressure difference. Thus, the flow of the liquid refrigerant from the discharge chamber to the low pressure side of the closed housing is prevented, and the occurrence of liquid compression of the compressor is prevented.

As described above, during operation of the compressor,
Since the on-off valve closes the through hole, the discharge chamber and the low-pressure side in the closed housing are not communicated with each other, so that the compressor performance does not deteriorate.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 3 is a sectional view of a horizontal hermetic scroll compressor to which the present invention is applied.

In FIG. 3, a scroll type compression mechanism C is provided on the right side inside a barrel-shaped sealed housing 8 installed horizontally, and an electric motor M is provided on the left side.

The scroll-type compression mechanism C allows the fixed scroll 1, the orbiting scroll 2, and the orbiting scroll 2 to revolve and rotate, but the rotation preventing mechanism 3, such as an Oldham ring, for preventing the rotation, the rotating shaft 5, and the like. It comprises a main bearing 71 and a sub-bearing 72 for supporting the rotary shaft 5, a orbiting bearing 73 and a thrust bearing 74 for supporting the orbiting scroll 2, and the like.

The fixed scroll 1 has an end plate 11 and a spiral body 12 erected on the inner surface of the end plate 11, and the end plate 11 is provided with a discharge port 13. Orbiting scroll 2
1 includes an end plate 21 and a spiral body 22 erected on the inner surface of the end plate 21, and a drive bush 25 is rotatable via a slewing bearing 73 in a boss 23 erected on the outer surface of the end plate 21. It is fitted in.

An eccentric pin 53 projecting from the right end of the rotary shaft 5 is rotatably fitted in an eccentric hole formed in the drive bush 25.

The fixed scroll 1 and the orbiting scroll 2 are mutually eccentric by the orbital radius, and
A plurality of closed spaces 2 are symmetrically point-symmetric with respect to the center of the spiral by engaging at an angle shifted by 180 °.
4 will be formed.

14 is a discharge chamber, 17 is a discharge valve for opening and closing between the discharge port 13 and the discharge chamber 14, 15 is a discharge cover to which the discharge valve 17 is attached and separates the discharge chamber 14 from the low pressure side 81,
Reference numeral 151 denotes a discharge path provided in the discharge cover 15 and opened and closed by a discharge valve 17.

The present invention relates to an improvement of the discharge cover 15 described above. That is, FIGS. 1 and 2 are sectional views of the discharge cover 15 of the hermetic scroll compressor according to the embodiment of the present invention.

In FIG. 1 and FIG. 2, a through hole 20 is formed in a lower portion of the discharge cover 15, that is, in a portion where the discharge chamber 14 and the low pressure side 81 in the closed housing 8 can communicate. I have.

Reference numeral 16 denotes an on-off valve for opening and closing the through hole 20, which is a reed valve made of a flexible plate material.
The upper end thereof is fixed to a mounting surface of the discharge cover 15 on the side of the discharge chamber 14 by a bolt 41. The on-off valve 16 can open and close the through hole 20 by bending toward the discharge chamber 14 with the mounting portion formed by the bolt 41 as a fulcrum due to a pressure difference between the discharge chamber 14 and the low pressure side 81 in the closed housing. It is composed of

A barrel-shaped oil tank 9 is installed horizontally below the closed housing 8, and the oil tank 9 is connected to the closed housing 8 by a connecting pipe 92 and a suction pipe 93.

During the operation of the hermetic scroll compressor constructed as described above, as shown in FIG.
Eccentric pin 53, drive bush 25, slewing bearing 73,
The orbiting scroll 2 is driven via the boss 23, and the orbiting scroll 2 is caused to orbit on a circular orbit having an orbital orbital radius while being prevented from rotating by the anti-rotation mechanism 3.

Then, the refrigerant gas enters the low-pressure side 81 in the closed housing 8 via the suction pipe 82 to cool the electric motor M, and then passes through a not-shown passage formed in the frame 6 to seal the compression chamber. Inhaled into 24. The refrigerant gas reaches the center of the spiral while being compressed as the volume of the compression chamber 24 decreases due to the revolving orbiting motion of the orbiting scroll 2, and pushes the discharge valve 17 from the discharge port 13 to open the discharge chamber. 14 and is discharged to the outside through a discharge pipe 83 from here.

During operation of the compressor as described above, when the oil pump 91 provided at the shaft end of the rotary shaft 5 is driven,
The lubricating oil in the oil tank 9 is sucked up through the suction pipe 93 and is urged by the oil pump 91. And
After lubricating the required lubrication points of the scroll-type compression mechanism C through an oil passage 94 formed inside the rotary shaft 5, the oil is dropped on the bottom of the housing chamber 81.

The lubricating oil dropped on the bottom of the low-pressure side 81 in the closed housing passes through the connecting pipe 92 and passes through the oil tank 9.
Go inside and be stored in this.

However, when the compressor is stopped for a long time, there is no pressure difference between the discharge chamber 14 and the low pressure side 81 in the closed housing, so that the on-off valve 16 provided on the discharge cover 15 opens the through hole 20. Become. Even if the refrigerant liquefied by the migration accumulates in the discharge chamber 14 in such a state, the refrigerant flows through the through hole 2.
0 and is returned to the low pressure side 81 in the sealed housing.

Further, when the compressor is started, the pressure in the closed housing decreases and the pressure in the discharge chamber 14 increases, so that the on-off valve 16 provided on the discharge cover 15 is caused by the pressure difference. Close the hole. As a result, the flow of the mixed liquid of the liquefied refrigerant and the lubricating oil from the discharge chamber 14 to the compression closed space 24 in the closed housing 81 is prevented, and the occurrence of liquid compression of the compressor is prevented.

In the above embodiment, the horizontal scroll compressor has been described. However, the present invention can be applied to a vertical scroll compressor by appropriately selecting the mounting locations of the through hole 20 and the on-off valve 16 in the discharge cover 15.

[0036]

The present invention is configured as described above.
According to the present invention, when the compressor is stopped, the on-off valve provided on the discharge cover is opened, and the discharge chamber communicates with the low-pressure side in the closed housing, thereby preventing the liquid refrigerant from accumulating in the discharge chamber. At the same time, during operation of the compressor, the on-off valve closes the through hole due to a rise in pressure in the discharge chamber, and the flow of the liquid refrigerant from the discharge chamber to the low pressure side of the closed housing is prevented.

As a result, the occurrence of liquid compression during the operation of the compressor and the resulting damage to the swirl chamber components and bearings and the occurrence of seizure are prevented.
Reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a discharge cover of a scroll compressor according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a cross-sectional view of a horizontal hermetic scroll compressor.

FIG. 4 is a system diagram of a refrigeration cycle.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 compressor C scroll compression mechanism 1 fixed scroll 2 orbiting scroll 13 discharge port 14 discharge chamber 15 discharge cover 16 on-off valve 17 discharge valve 20 through hole

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Katsumi Hirooka 3-1-1, Asahi-cho, Nishibiwajima-cho, Nishi-Kasugai-gun, Aichi Prefecture Inside of Air Conditioning Works of Mitsubishi Heavy Industries, Ltd.

Claims (2)

[Claims] 1. A closed housing is partitioned into a discharge chamber and a low-pressure side by a discharge cover, and a scroll compression mechanism is arranged on the low-pressure side, and discharge gas from a discharge port of the compression mechanism is supplied to a discharge passage of the discharge cover. A hermetic scroll compressor that discharges to the discharge chamber through the discharge chamber and discharges to the outside from a discharge pipe connected to the discharge chamber, wherein the low-pressure side communicates with the inside of the discharge chamber at a low position of the discharge cover. Drill a hole, and in the through hole,
A hermetic scroll compressor comprising an opening / closing valve that closes a through hole with discharge pressure during operation and opens when stopped. 2. The hermetic scroll compressor according to claim 1, wherein said on-off valve comprises a plate-shaped reed valve.