JPH0361680A - Oil separator - Google Patents

Abstract

PURPOSE:To surely prevent the clogging of foreign materials in an oil return passage by arranging a valve covering the inlet of the oil return passage, onto the oil storage chamber side of the oil return passage for the communication between an oil storage chamber and the low pressure part in a compressor. CONSTITUTION:A storage chamber 39 for storing the oil O which is separated and recovered is formed on the projection part 26 of a rear side cylinder block 2, and an expansion chamber 34 and an oil storage chamber 39 communicate through a fine hole 42. An oil returning passage 43 is formed between the bottom part of the oil storage chamber 39 a swash plate chamber 8 as low pressure part, and the oil O in the oil storage chamber 39 is drip-supplied into the swash plate chamber 8, passing through the oil return passage 43. In the oil storage chamber 39, a lead valve 44 is tightening-fixed in the state covering the inlet of the oil return passage 43. The inlet of the oil return passage 43 is always kept in the covered state by the lead valve 44, and the oil O is supplied into the oil return passage 43 in the leak state from the lead valve 44, and the intrusion of foreign materials into the oil return passage 43 is surely suppressed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention separates the lubricating oil contained in the refrigerant gas from the refrigerant in an oil separation section provided in the high pressure section of the compressor or in the middle of the high pressure piping of the external cooling circuit. The present invention relates to an oil separator for a compressor configured to separate oil from gas and return the separated oil to a low-pressure section in a compressor or to a suction pipe of the compressor.

[Prior Art] In a compressor such as a swash plate compressor, lubricating oil that lubricates moving parts is contained in refrigerant gas in the form of a mist.

Therefore, when the refrigerant gas compressed inside the compressor is discharged and circulated to the external cooling circuit, the mist of lubricating oil is also discharged and circulated to the cooling circuit, and this oil is applied to the inner wall of the evaporator in the cooling circuit, etc. It adheres and interferes with heat exchange.

Therefore, in the past, an oil separator was installed separately outside the compressor and connected via piping between the compressor and the cooling circuit, and when the refrigerant gas compressed inside the compressor was discharged to the cooling circuit, the refrigerant gas It has been proposed that the lubricating oil contained in the compressor is separated by an oil separator, and the separated oil is returned to the low pressure section inside the compressor through an oil return pipe for reuse. A compressor has also been proposed in which lubricating oil contained in refrigerant gas is separated from refrigerant gas in a high pressure section of the compressor, and the separated oil is returned to a low pressure section of a pressure A machine. .

In this type of compressor, the amount of oil returned during normal operation of the compressor is a predetermined amount.Moreover, when the oil in the oil storage chamber runs out, high-pressure refrigerant gas is returned to the low-pressure part through the oil return passage. In order to prevent the oil from being supplied, the diameter of the oil return passage is formed to be less than one inch.

[Problems to be Solved by the Invention] The diameter of the oil return passage must be accurately formed in order to return a predetermined amount of oil, but the small diameter makes machining difficult, especially for compressor cylinder blocks or housings. This problem becomes more noticeable when high-silicon aluminum is used as the material. In addition, because the diameter is small, the oil return passage may be clogged with foreign matter such as metal powder that is generated during compressor machining and remains in the compressor due to incomplete removal, or metal powder generated at sliding parts.
There are cases where oil is not returned to the low pressure section where the pressure is 1fi, and the amount of lubricating oil becomes insufficient.

As a result, the lubrication of the sliding parts of the compressor, such as the piston and shoes, becomes inadequate, causing problems such as seizure of the sliding parts and accelerated wear, resulting in reduced durability and reliability.

The present invention has been made in view of the above problems, and includes:
Its purpose is to return the oil, which is separated from the refrigerant gas in the high-pressure section of the compressor or in the middle of the high-pressure piping of the external cooling circuit and stored in the oil storage chamber, to the low-pressure section of the compressor. It reliably prevents foreign objects from clogging the return passage and reliably returns the oil separated in the oil separation section to the low pressure section of the pressure machine, ensuring that the oil necessary for lubricating each sliding section is always available. Moreover, it is an object of the present invention to provide an oil separator whose oil return passage is easy to process.

[Means for Solving the Problems] In order to achieve the above-mentioned object, in the present invention, lubricating oil contained in refrigerant gas is separated by oil separation provided in the high-pressure section of a pressure tram or in the middle of high-pressure piping of an external cooling circuit. In a compressor configured to separate oil from refrigerant gas at a section and return the separated oil to a low pressure section within the compressor or to a suction pipe of the compressor, the oil separated at the oil separation section is temporarily stored. A storage chamber is provided, and a valve that covers the inlet of the oil return passage is disposed on the oil storage chamber side of the oil return passage that communicates the oil storage chamber with the low pressure section in the compressor or the suction pipe.

[Operation] When the compressor equipped with the oil separator of the present invention is operated, the refrigerant gas compressed inside the compressor is guided to the oil separator provided in the high pressure section or in the middle of the high pressure piping of the external cooling circuit. , oil is separated from the refrigerant gas and stored in an oil storage chamber. When an oil separator is provided inside the compressor, the oil stored in the oil storage chamber and the low pressure section (II
The oil is returned to the low pressure section of pressure all through an oil return passage communicating with the swash plate chamber. In addition, when an oil separator is installed in the middle of the high-pressure piping of the external cooling circuit, the oil C stored in the oil storage chamber is passed through the oil return passage that communicates the oil storage chamber with the suction piping of the compressor. It is returned to the low pressure section with a pressure of mN.

The oil return passage is kept covered by the inlet valve, and the oil in the oil reservoir enters the oil return passage by leaking from the seal portion of the valve.

In the case of low viscosity oil, even if the valve seat is smooth,
Oil gradually leaks from the valve seal.

In addition, in the case of highly viscous oil, the valve seat surface is machined to a roughness that allows appropriate oil leakage, and the oil in the oil reservoir flows into the oil return passage without opening the valve. In other words, since the entrance of the oil return passage is always covered by a valve, foreign objects will not clog the oil return passage.
The oil separated in the oil separation section is reliably returned to the low pressure section of the compressor through the oil return passage. In addition, there is no need to adjust the diameter of the oil return passage to adjust the amount of oil returned.
When forming the oil return passage, the diameter can be made large and precision is not required, making the process easy.

[Example 1] Hereinafter, an example in which the present invention is embodied in a swash plate type pressure tam will be described with reference to FIGS. 1 to 6.

As shown in FIG. 3, both ends of the front and rear cylinder blocks 1.2 are closed by front and rear housings 5.6 via valve plates 3.4, which are connected by a plurality of bolts 7. are connected by.

A swash plate chamber 8 is formed at the joint portion of the cylinder blocks 1.2, and the swash plate chamber 8 has a shaft hole 1a at the center of both cylinder blocks 1.2.

A swash plate 10 fixed to a drive shaft 9 passing through 2a is accommodated. As shown in FIGS. 3 to 5, five pairs of cylinder bores 11 are formed in the cylinder block 1.2 in parallel with the drive shaft 9 and at radial positions around the drive shaft 9,
A double-headed piston 12 is fitted into each cylinder bore 11. Each piston 12 is moored to the swash plate 10 via a shoe 13, and is reciprocated within the cylinder bore 11 by the rocking of the swash plate 10 as the drive shaft 9 rotates.

A suction chamber 14.15 is formed between the centers of the front and rear housings 5.6, and a discharge chamber 1 is formed on the outer periphery.
6.17 is formed. Also, both valve plates 3.
4 has an inlet port 18°19 and an outlet port 20.21, respectively.
is formed. Furthermore, an intake valve 22.23 is provided on the cylinder block 1.2 side of the valve plate 3.4, and the housing 5, 61111 of the valve plate 3.4
are provided with discharge valves 24,25.

A protrusion #26 for sucking and discharging refrigerant gas G is provided at the upper part of the rear cylinder block 2.
As shown in FIG. 4, a gas port 27 opening into the swash plate chamber 8 is formed. Between the respective cylinder bores 11 in both cylinder blocks 1.2, five suction passages 28, 29 for communicating the swash plate chamber 8 and the suction chamber 14, 15 are formed. The refrigerant gas G sucked into the suction chamber 14.15 is introduced into the suction chamber 14.15 through the suction passage 28.29.

As shown in FIG. 1.4.5, a shell 33 is attached to the protrusion 26 via a shielding plate 31 and a pore-forming plate 32, and an expansion chamber 34 is formed inside the shell 33.

A pair of discharge pipes 35 are provided sideways on the 311M plate 31 in the MM chamber 34, and their upper ends are connected to the expansion chamber 3.
It opens toward the center of 4. Each discharge pipe 35
A pair of gas outlets 36 are formed in the rear cylinder block 2 so as to communicate with the discharge chambers 16 and 17.
Compressed refrigerant gas flows from the discharge chamber 16.17 to this gas outlet 36.
and is discharged into the expansion chamber 34 via the discharge pipe 35.

A suction pipe 37 projects from the shell 33 and is connected to the gas port 27 at its base end.

Further, a discharge pipe 38 is fixed to the shell 33 in such a manner that its end protrudes below the opening of the discharge pipe 35 in the expansion chamber 34.
A refrigerant gas flow directed to the discharge pipe 38 collides with the lower end 38a of the discharge pipe 38, and mist-like oil 0 contained in the gas flow adheres to the outer periphery of the lower end 38a and is separated and collected. . Further, the refrigerant gas in the expansion chamber 34 is supplied to an external cooling channel (not shown) via a discharge pipe 38.

An oil storage chamber 39 for storing separated and recovered oil 0 is formed on the protrusion 26 of the rear cylinder block 2 at the lower part of the expansion chamber 34 . A through hole 40 is formed in the shielding plate 31 between the expansion chamber 34 and the oil storage chamber 39 so as to be located directly below the lower end 38a of the discharge pipe 38, and a through hole 40 is formed in the lower part of the shielding plate 31 so as to be located directly below the lower end 38a of the discharge pipe 38. A filter 41 is attached to protect the air. Fifth
As shown in the figure, a pair of pores 42 are formed in the pore forming plate 32 corresponding to the outer peripheral edges of the through holes 40, and the expansion chamber 34 and the oil storage chamber 39 communicate with each other through the pores 42. has been done.

An oil return passage 43 is formed extending almost vertically between the bottom of the oil storage chamber 39 and the swash plate chamber 8 serving as a low pressure section, and communicates the two. 43 into the swash plate chamber 8. There is a wall inside the oil storage chamber 39.
The door valve 44 covers the entrance of the oil return passage 43, and is fixedly tightened by a screw 45 at its base end.

In order to allow oil O to leak from the contact surface of the reed valve 44 into the oil return passage 43 even when the reed valve 44 covers the inlet, the oil return passage in the oil storage chamber 39 is closed as shown in FIG. F! The area around the inlet of @43 is processed by 111 or shot blasting to have a predetermined surface roughness corresponding to the viscosity of the oil used.

Next, the operation of the apparatus configured as described above will be explained.

Now, when the swash plate 10 is rotated by the rotation of the drive shaft 9,
Each piston 12 is reciprocated in the left-right direction in FIG. 3 within the cylinder bore 11 to suck in, compress, and discharge refrigerant gas G. The compressed refrigerant gas G is discharged into the discharge chamber 16
．． 17, is discharged into the expansion chamber 34 through the gas outlet 36 and the discharge pipe 35, and after the flow rate is reduced in the expansion chamber 34, it is supplied through the discharge pipe 38 to an external cooling circuit (not shown). When the refrigerant gas G is discharged from the open end of the discharge vibrator 35 into the expansion chamber 34, the refrigerant gas flow collides with the lower end 38a of the discharge pipe 38, so that the mist contained in the waste flow is The separated and collected oil O adheres to the outer periphery of the lower end 38 a and is separated and collected. The separated and collected oil O falls from the lower end 38 a to the bottom of the expansion chamber 34 and passes through the through hole 40 , filter 41 and pore 42 . The oil is dripped and stored in the oil storage chamber 39. Furthermore, this stored oil O is dripped and supplied to the swash plate chamber 8 of the pressurizer through the oil return passage 43, and is used to lubricate sliding parts such as the piston 12 and the shoe 13.

The inside of the oil storage chamber 39 is in a high pressure state equivalent to the discharge pressure like the inside of the expansion chamber 34, and the reed valve 4ii is always kept in a state covering the entrance of the oil return passage 43, but the oil 0 is kept between the reed valve 44 and the inlet. Oil return passage 43 from between the contact surface
The oil leaks in an approximately constant amount and is dripped into the swash plate chamber 8 through the oil return passage 43. That is, the oil return passage 4
3 is always kept covered by the reed valve 43, and the oil 0 is supplied to the oil return passage 43 while leaking from the reed valve 44, thereby reliably preventing foreign matter from entering the oil return passage 43. The oil O separated in the oil separation section is reliably returned to the swash plate chamber 8 through the oil return passage 43 and used to lubricate each sliding part, thereby ensuring that the piston 12, shoe 13, etc. are prevented from seizing. Prevented. In addition, since there is no need to adjust the return amount of oil 0 for the [1 diameter] of the oil return passage 43, when forming the oil return passage 43, the diameter can be made large and precision is not required, making the machining easier.

[Example 2] Next, a second embodiment will be explained according to FIG. 7.8.

In this embodiment, a ball valve 46 is used instead of the reed valve 44 as a valve that covers the entrance of the oil return passage 43, and the other configurations are the same.

The pawl 46a of the ball valve 46 is disposed to cover the entrance 1 of the oil return passage 43, and is biased by a rib 47. Also in this embodiment, the oil O in the oil storage chamber 39 leaks from between the ball valve 46 and its abutment surface in a substantially constant amount, and is dripped into the swash plate chamber 8 through the oil return passage 43 . In order to adjust the amount of leakage of the highly viscous oil O, instead of making the entire area around the entrance of the oil return passage 43 a predetermined roughness, a groove 48 is formed on the valve seat surface as shown in FIG. Streaks may be formed.

Note that the present invention is not limited to the above embodiments, and for example, a mushroom-shaped valve body 49 whose tip end is loosely inserted into the oil return passage 43 may be used as shown in FIG. . Further, when the reed valve 44 is used as in the first embodiment, the reed valve may be provided with an initial warp so that it becomes open when the pressure in the oil storage chamber 39 and the pressure in the low pressure section are equal. . With this configuration, foreign matter accumulated around the reed valve can be removed from the oil return when the compressor has not been operated for a long time and the pressure in the oil storage chamber 39 becomes equal to the pressure in the low pressure section. The oil storage chamber 3 passes through the passage 43
It is discharged to 9. Since the diameter of the oil return passage 43 is larger than the size of the foreign matter, the oil return passage 43 will not be clogged with foreign matter.

Alternatively, the oil O in the oil storage chamber 39 may be returned to the swash plate chamber 8 through a low-pressure part communicating with the swash plate chamber 8 instead of being returned directly to the swash plate chamber 8, or a separate structure may be used to separate the oil O from the refrigerant gas. The structure may be adopted. Furthermore, the present invention may be applied to a compressor other than a swash plate type compressor, or an oil separator may be provided in the middle of a high-pressure pipe of an external cooling circuit of the compressor.

[Effects of the Invention] As described in detail above, according to the present invention, the entrance of the oil return passage is kept covered by the valve, and the oil in the oil storage chamber leaks from the seal portion of the valve and flows into the oil return passage. This prevents foreign matter from clogging the oil return passage, and the oil separated in the oil separation section is reliably returned to the low pressure part of the compressor via the oil return passage, ensuring that the amount of oil necessary for lubrication is always maintained. This lubricates each part and reliably prevents seizure of pistons, shoes, etc.

In addition, since there is no need to adjust the diameter of the oil return passage to adjust the amount of oil returned, the oil return passage can be formed with a large diameter and does not require precision, making it easy to process and prevent foreign objects from entering the oil return passage. You won't get stuck in the aisles either.

[Brief explanation of drawings]

1 to 6 show a first embodiment embodying the present invention, in which FIG. 1 is a partial sectional view showing the structure of an oil separator, FIG. 2 is an enlarged sectional view of the main part, and FIG. 4 is a sectional view taken along line IV-IV in FIG. 1, FIG. 5 is a sectional view taken along line v-v in FIG. 1,
FIG. 6 is a plan view of the reed valve, FIG. 7 is a sectional view of the main part of the second embodiment, FIG. 8 is an enlarged plan view of the valve seat, and FIG. 9 is a sectional view of the main part of a modified example. Cylinder block 1.2, swash plate chamber 8 as a low pressure part of the compressor, expansion chamber 34, discharge pipe 38, oil storage chamber 39
, oil return passage 43, reed valve 44, ball valve 46,
Spring 48, refrigerant gas G, oil O1

Claims (1)

[Claims] 1. The lubricating oil contained in the refrigerant gas is separated from the refrigerant gas at an oil separation section installed in the high pressure section of the compressor or in the middle of the high pressure piping of the external cooling circuit, and the separated oil is transferred to the low pressure section inside the compressor. Alternatively, in a compressor configured to be returned to the suction piping of the compressor, an oil storage chamber is provided to temporarily store the oil separated in the oil separation section, and the oil storage chamber and the low pressure section in the compressor or the suction piping are connected. An oil separator that is provided with a valve that covers the entrance of the oil return passage on the oil storage chamber side of the oil return passage that communicates with the oil return passage.