JP2943181B2 - Oil separation structure of compressor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an oil separation structure of a compressor used for a cooling device or the like.

[Prior Art] In a swash plate compressor, a lubricating portion such as a radial bearing for supporting a drive shaft, a thrust bearing, and a shoe or a piston for transmitting the swinging motion of a swash plate to a piston as reciprocating motion is provided. Is contained in the refrigerant gas in the form of a mist. And when the refrigerant gas compressed inside the compressor is discharged and circulated to the external cooling circuit,
When the mist-like oil is discharged and circulated to the cooling circuit, the oil adheres to the inner wall of the evaporator in the cooling circuit and hinders heat exchange. Therefore, conventionally, there has been proposed a compressor configured to separate lubricating oil contained in a refrigerant gas from a refrigerant gas at a high pressure portion of the compressor and return the separated oil to a low pressure portion of the compressor. I have. In this type of compressor, refrigerant gas containing oil is guided from a discharge hole of the compressor through a discharge passage into an expansion chamber (volume chamber) swelled in the compressor casing, and enters a service flange on the discharge side. The oil is separated in between and accumulates in the oil storage chamber. Then, the oil stored in the oil storage chamber is returned to a low-pressure section such as a swash plate chamber through an oil return passage.

Also, in compressors other than the swash plate compressor, an oil separating section for separating oil contained in the refrigerant gas is provided. For example, Japanese Utility Model Laid-Open Publication No. Sho 57-168792 discloses, as shown in FIG. 7, a compressor housing 61 of a vane type compressor, which communicates with a refrigerant gas discharge port 62 of the housing 61 and a discharge port on the upper side. Oil reservoir 64 with 63
The refrigerant gas discharge port 62 is provided in the oil storage chamber 64.
A baffle plate 65 that separates the refrigerant gas discharged from the refrigerant gas discharge port 62 into the oil storage chamber 64 against the baffle plate 65 to separate the oil in the refrigerant gas, thereby providing an oil storage chamber. There is disclosed one that is stored in a chamber 65 and used for lubrication of each part.

[Problems to be Solved by the Invention] In the conventional oil separation method, all of the refrigerant gas is once discharged into the oil separation chamber (oil storage chamber), and then guided again to the discharge passage (discharge passage). However, the oil separation chamber (oil storage chamber) contains a large amount of oil mist, and when the flow rate of the refrigerant increases and the flow velocity of the refrigerant increases, such as when the rotation speed increases or the suction pressure increases, the oil is separated once. There is a problem that the oil which has been trapped in the refrigerant gas flowing toward the discharge passage is discharged to the external cooling circuit, and the oil separation efficiency is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to increase the oil separation efficiency even when the rotation speed of the compressor is increased, and to further reduce the oil composition of the compressor. It is to provide a separation structure.

[Means for Solving the Problems] On the discharge side, the refrigerant is always in a gaseous state after being compressed, and when the oil contained in the refrigerant gas in the form of mist moves along the refrigerant line with the refrigerant gas, the oil Does not flow along the pipeline in harmony with the refrigerant gas in the mist state, the refrigerant gas flowing in the center of the pipeline contains little oil, and the refrigerant gas flowing near the wall contains a large amount of oil The present invention has been made based on this finding.

In order to achieve the above object, according to the present invention, one end of an introduction pipe for introducing refrigerant gas from a discharge side into an oil separation chamber having an oil return passage communicating with a low pressure portion of a compressor is opened. A discharge pipe was provided in a state where the end portion was loosely inserted into the pipe, and a passage communicating between the middle of the discharge pipe and the oil separation chamber was provided.

[Operation] When the compressor is operated, the refrigerant gas from the discharge side is guided to the oil separation chamber via the introduction pipe. When the refrigerant gas containing mist-like oil flows through the introduction passage, the refrigerant gas flowing through the central portion of the introduction pipe contains little oil, and the refrigerant gas flowing near the wall surface contains a large amount of oil. Refrigerant gas containing almost no oil flowing in the central part of the introduction pipe is directly led to the discharge pipe loosely inserted into one end of the introduction pipe, and refrigerant gas containing a large amount of oil is led into the oil separation chamber. . The oil contained in the refrigerant gas introduced into the oil separation chamber collides with the wall surface of the oil separation chamber or the outer peripheral surface of the discharge pipe, is separated from the refrigerant gas, accumulates in the oil reservoir, and passes through the oil return passage. It is returned to the low pressure section of the compressor. Further, the refrigerant gas from which the oil has been separated is guided to the discharge line through a passage communicating the middle of the discharge line and the oil separation chamber, and the refrigerant gas directly guided from the introduction line to the discharge line. Join.

Embodiment 1 Hereinafter, a first embodiment in which the present invention is embodied in a swash plate compressor will be described with reference to FIGS.

As shown in FIG. 2, both ends of the cylinder blocks 1 and 2 opposed to each other are closed by front and rear housings 5 and 6 via valve plates 3 and 4, respectively. Fixed. A swash plate chamber 8 is formed in a joint portion between the cylinder blocks 1 and 2, and the swash plate chamber 8 is rotatable through radial bearings 9 in shaft holes 1 a and 2 a provided through the centers of the cylinder blocks 1 and 2. The swash plate 11 is housed in a state fitted on the supported drive shaft 10. A thrust bearing 12 is interposed between both end faces of the boss 11a of the swash plate 11 and the cylinder blocks 1 and 2. As shown in FIG. 3, five pairs of cylinder bores 13 are formed in the cylinder blocks 1 and 2 at a radiation position parallel to the drive shaft 10 and centered on the drive shaft 10. The pistons 14 on both sides are slidably housed. Each piston 14 is moored to the swash plate 11 via the shoe 15, and is reciprocated within the cylinder bore 13 by the swing of the swash plate 11 with the rotation of the drive shaft 10 to perform a compression operation.

In the front and rear housings 5, 6, suction chambers 16, 17 are formed on the center side, and discharge chambers 18, 19 are formed on the outer peripheral side. In addition, suction ports 20, 21 and discharge ports 22, 23 are formed in both valve plates 3, 4, respectively. Further, suction valves 24, 25 are provided on the cylinder block 1, 2 side of the valve plates 3, 4, and the housing of the valve plates 3, 4 is provided.
Discharge valves 26 and 27 are provided on the fifth and sixth sides.

Refrigerant gas G is provided above the rear cylinder block 2.
A protrusion 28 is provided for suction and discharge of the gas, and the protrusion 28 has a gas inlet 29 opening into the swash plate chamber 8 as shown in FIG.
Are formed. Between the cylinder bores 13 of the two cylinder blocks 1 and 2, five suction passages 30 and 31 for communicating the swash plate chamber 8 with the suction chambers 16 and 17 are formed. The refrigerant gas G sucked into the suction chambers is introduced into the suction chambers 16 and 17 through the suction passages 30 and 31.

As shown in FIGS. 1 and 3, a shielding plate 32 is provided on the projection 28.
A shell 34 is attached via a pore forming plate 33, and an expansion chamber 35 as an oil separation chamber is formed therein. In the expansion chamber 35, a pair of introduction pipes 36 project from above the shielding plate 32, and a pair of gas is supplied to the rear cylinder block 2 so that the lower end thereof communicates with the discharge chambers 18 and 19. A passage 37 is formed, and the compressed refrigerant gas is discharged from the discharge chambers 18 and 19 into the expansion chamber 35 through the gas passage 37 and the introduction pipe 36.

A suction pipe 38 protrudes from the shell 34 and is connected to the gas inlet 29 at a base end thereof. A discharge pipe 39 having a pair of branch paths 39a as a discharge pipe is fixed to the shell 34 in a state where the end of the branch path 39a is loosely inserted into the introduction pipe 36. The discharge pipe 39 is formed integrally with a recovery pipe 40 as a passage communicating the expansion chamber 35 and the discharge pipe 39 at an intermediate position between the two branch paths 39a. The refrigerant gas in the expansion chamber 35 is supplied to an external cooling circuit (not shown) via a discharge pipe 39.

As shown in FIG. 1, an oil storage section 41 for storing the separated and recovered oil O is formed below the expansion chamber 35. A through hole 42 is formed in the shielding plate 32 between the expansion chamber 35 and the oil reservoir 41 so as to be located immediately below the lower end of the recovery pipe 40, and dust or the like mixed in the oil O is formed below the through hole 42. A filter 43 is installed for passing through. A pair of fine holes 44 are formed in the fine hole forming plate 33 with respect to the outer peripheral edge of the through hole 42, and the expansion chamber 35 and the oil reservoir 41 communicate with each other through the fine holes 44. An oil return passage 45 communicating between the bottom of the oil storage portion 41 and the swash plate chamber 8 as a low pressure portion is formed so as to extend substantially vertically, and the oil O in the oil storage portion 41 is returned to the oil return passage 45. Through the swash plate chamber 8.

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

Now, when the swash plate 11 is rotated by the rotation of the drive shaft 10,
Each piston 14 is reciprocated in the cylinder bore 13 in the left-right direction in FIG. 2 to suck, compress, and discharge the refrigerant gas G. The compressed refrigerant gas G is guided from the discharge chambers 18 and 19 to the introduction pipe 36 from the gas passage 37. Discharge chamber 18,1
The refrigerant gas introduced from 9 into the gas passage 37 contains mist-like oil, and has a two-phase flow of a gas phase (refrigerant gas) and a liquid phase (mist-like oil). When a gas-liquid two-phase flow flows through an elongated pipe, a so-called annular flow in which the gas phase flows through the center of the pipe and the liquid phase flows through the periphery of the pipe, and this phenomenon is more pronounced when the flow is gentle. become.
Therefore, when the refrigerant gas discharged from the discharge chambers 18 and 19 into the gas passage 37 is introduced into the expansion chamber 35 via the introduction pipe 36, at the time when the refrigerant gas is introduced into the expansion chamber 35 from the introduction pipe 36. Mist oil O is hardly contained in the refrigerant gas flowing through the central portion of the introduction pipe 36, and a large amount of mist oil O is contained in the refrigerant gas flowing near the wall surface of the introduction pipe 36. . Then, the refrigerant gas containing almost no oil O flowing through the central portion of the introduction pipe 36 is directly led to the branch path 39a, and is supplied to the external cooling circuit via the discharge pipe 39.
On the other hand, the refrigerant gas containing a large amount of mist-like oil O flowing near the wall surface of the introduction pipe 36 is discharged to the expansion chamber 35, and the refrigerant gas flow collides with the outer peripheral surface of the branch path 39a and the wall surface of the expansion chamber 35. As a result, oil is separated from the refrigerant gas. That is, since the refrigerant gas discharged into the expansion chamber 35 and separating the oil in the expansion chamber 35 has a high oil content, the separation efficiency is improved. Then, the refrigerant gas from which the oil has been separated is guided to the discharge pipe 39 via the recovery pipe 40, and merges with the refrigerant gas directly guided to the discharge pipe 39 from the introduction pipe 36 via the branch path 39a to be cooled externally. Supplied to the circuit.

Oil O separated from the refrigerant gas passes through the through-hole 42,
The oil is stored in the oil storage portion 41 through the holes 43 and the fine holes 44, is supplied dropwise to the swash plate chamber 8 through the oil return passage 45, and is used for lubricating movable parts such as the thrust bearing 12, the piston 14, and the shoe 15. . When the number of rotations of the compressor increases, the amount of oil returned to the swash plate chamber 8 decreases, and there is a possibility that lubrication of each part may not be sufficiently performed. However, in the case of the present invention, the oil separation efficiency is high. In addition, even when the rotational speed of the compressor increases, the amount of oil supplied to the swash plate chamber 8 through the oil return passage 45 can be sufficiently ensured. For example, when the cross-sectional area of the branch path 39 is set so that the amount of gas flowing through the branch path 39 is の of the total gas amount, as shown by a broken line in FIG. The oil return amount could be secured up to twice the number of rotations.

Second Embodiment Next, a second embodiment embodied in a rotary type compressor (rotary compressor) will be described with reference to FIG. The rotary compressor has a housing 53 in which a compressor mechanism (not shown) that accommodates a compressor mechanism (not shown) in which a cylindrical rotary piston eccentric to the cylinder rotates while maintaining contact with the tip of the slide valve to compress the refrigerant gas. An expansion chamber 35 as a muffler / oil separation chamber is formed at one end. In the expansion chamber 35, an introduction pipe 36 for guiding the refrigerant gas discharged from the discharge hole 54 downward, and a discharge pipe 55 for discharging the refrigerant gas after oil is separated to an external cooling circuit are provided. ing. The outlet side of the introduction line 36 is bent downward, and one end of the discharge line 55 is loosely inserted into the end of the introduction line 36, and a recovery passage 51 is formed in the middle.

Therefore, also in this embodiment, the refrigerant gas containing almost no oil flowing through the central portion of the introduction pipe 36 is guided to the discharge pipe 55 without being discharged into the expansion chamber 35. On the other hand, the refrigerant gas containing a large amount of oil flowing near the wall surface of the introduction pipe 36 is discharged to the expansion chamber 35, and the oil is separated in the expansion chamber 35. Then, the refrigerant gas from which the oil O has been separated is guided to the discharge pipe 55 through the recovery passage 51, merges with the refrigerant gas directly guided from the introduction pipe 36, and is discharged to the external cooling circuit. The oil O separated from the refrigerant gas accumulates at the bottom of the expansion chamber 35 and is supplied from the oil return passage 45 to a sliding portion or the like. In this case, as shown in FIG. 6, if an intermediate pipe 56 is provided between the introduction pipe 36 and the discharge pipe 55, the oil separation efficiency is further improved.

The present invention is not limited to the above embodiments. For example, in a swash plate type compressor, discharge chambers 18 and 19 are formed at the center side of the front housing 5 and the rear housing 6 and the two housings 5 and 6 are formed. The suction chambers 16 and 17 may be formed on the outer peripheral side, or may be applied to a variable capacity swash plate type compressor. Further, the present invention may be applied to other types of compressors such as a scroll compressor, a vane compressor, and a screw compressor.

[Effects of the Invention] As described above in detail, according to the present invention, the refrigerant gas from the discharge side flowing through the introduction pipe for guiding the mist-like oil-containing refrigerant gas to the oil separation chamber is located at the center of the introduction pipe. The refrigerant gas containing almost no oil flowing through is separated from the refrigerant gas containing a large amount of oil without being discharged to the separation chamber, and only the refrigerant gas containing a large amount of oil is released to the oil separation chamber to separate the oil. Therefore, even when the separation efficiency is improved and the number of revolutions of the compressor is increased, the amount of oil to be returned to the low-pressure section of the compressor can be secured.

[Brief description of the drawings]

1 to 4 show a first embodiment of the present invention. FIG. 1 is a sectional view of a main part, FIG. 2 is a sectional view showing the entire compressor, and FIG. FIG. 4 is a partially omitted cross-sectional view taken along the line III-III of FIG. 4, FIG. 4 is a diagram showing the relationship between the oil return amount and the number of revolutions of the compressor, FIG. Is a sectional view of a main part of a modified example, and FIG. 7 is a sectional view of a conventional device. The swash plate chamber 8 as a low-pressure part of the compressor, the expansion chamber 35 as an oil separation chamber, the introduction pipe 36, and the branch path 39 as a discharge pipe
a, a recovery pipe 40 as a passage, an oil reservoir 41, an oil return passage 45, a suction pipe 38 as an introduction pipe, a gas passage 49 as a discharge pipe, a pipe 50, a recovery passage 51 as a passage, and a discharge pipe 52, oil O.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Norihiko Nakamura 2-1-1 Toyota-cho, Kariya-shi, Aichi Inside Toyota Industries Corporation (56) References JP-A-2-264189 (JP, A) JP-A 3-67070 (JP, A) Fully open sho 59-1007085 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F04B 39/04 F04B 27/08

Claims (1)

(57) [Claims] A part of an introduction pipe for introducing refrigerant gas from a discharge side is opened in an oil separation chamber having an oil return passage communicating with a low-pressure part of a compressor, and an end of the introduction pipe has a free end. An oil separation structure of a compressor, wherein a discharge pipe is provided in an inserted state, and a passage communicating between the discharge pipe and the oil separation chamber is provided.