JP2003269336A - Compressor and oil separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To give high lubricating oil separating ability to a compressor without using additional parts. <P>SOLUTION: A housing 12 of the compressor 10 is provided with a compressing mechanism for sucking and compressing fluid, and an oil separating chamber 54 for separating lubrication oil mixed in the fluid discharged from the compressing mechanism from the fluid. The fluid compressed by the compressing mechanism is introduced into the oil separating chamber 54, making the lubricating oil mixed in the fluid come into contact with an inside wall 60 of the oil separating chamber 54. By providing protrusions and recesses on the inside wall 60, for example, the lubrication oil contacting surface area of the inside wall is increased, thus, the amount of lubrication oil mixed in the fluid introduced to the oil separating chamber 54 caught on the surface of the inside wall 60 increased. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor used in a refrigeration system, an air conditioner, etc., and more specifically,
The present invention relates to an oil separator for separating lubricating oil mixed in a fluid compressed by a compressor from the fluid.

[0002]

2. Description of the Related Art Compressors such as reciprocating compressors, rotary compressors and scroll type compressors generally have a compression mechanism including a fixed portion and a movable portion. A fluid such as a refrigerant gas or air is introduced into the compression space formed by the parts, and then the movable part is slid with respect to the fixed part, so that the fluid in the compression space is compressed. At this time, in order to smooth the sliding between the fixed part and the movable part, and to close the gap existing between the fixed part and the movable part, to enhance the sealing property (sealing property) of the compression space,
Lubricating oil is supplied between the fixed part and the movable part, but since the lubricating oil leaks into the compression space, it is mixed into the fluid introduced into the compression space during operation. In recent years, more and more compressors are designed to lubricate a compression mechanism and seal the compression space by intentionally mixing a mist-like lubricating oil with a fluid sucked into the compression space.

However, when the above compressor is used in a refrigeration system or an air conditioner, when the lubricating oil mixed in the fluid reaches the condenser, the heat transfer surface of the condenser is an oil film of the lubricating oil. This causes the problem of being covered and hindering the heat transfer action, lowering the refrigerating effect or the cooling effect, and the consumption of the lubricating oil causes a shortage of the lubricating oil, which may cause a lubrication failure accident.

Therefore, generally, in a refrigerating apparatus, an air conditioner, etc., an oil separator having an oil separation chamber for separating lubricating oil from a fluid is provided on the discharge side of a compression mechanism, and the compression mechanism is connected to the oil separator. A fluid consisting of a mixture containing discharged gas and mist-like lubricating oil is introduced, and the mist-like lubricating oil mixed in the fluid is brought into contact with the wall surface of the oil separation chamber to trap the lubricating oil on the wall surface I'm trying to separate it from. Further, the separated lubricating oil is further collected and returned to the compression mechanism again.

[0005]

In order to prevent the heat transfer effect of the condenser and the lack of the lubricating oil in the compressor, such an oil separator has a high lubricating oil separating ability. Is required. To meet this requirement, for example, the fluid introduced from the compression space of the compressor is spirally swirled in the separation chamber of the oil separator, and the mist-like lubricating oil having a higher specific gravity than the gas is separated by the centrifugal action into gas. There is an oil separator designed to separate the oil from. However, in the oil separator utilizing such centrifugal separation action, the fluid introduced into the separation chamber can obtain a sufficient swirling speed when the compressor is operating at a low rotation speed such as when the load is low. No
There is a problem that the centrifugal separation action is reduced and the lubricating oil separation ability is also reduced.

As disclosed in Japanese Unexamined Patent Publication No. Hei 5-195971, a compressor that compresses a compressor is disclosed in which fluctuations in the flow velocity when introduced into the separation chamber are unlikely to affect the lubricating oil separation capacity. There is an oil separator in which a member having a circular roof shape is arranged so as to face a discharge port from a space, and a fluid is made to collide with this member to separate lubricating oil from the fluid. However, in this case, it is necessary to add a member having a circular roof shape, and in order to improve the trapping rate of the lubricating oil, it is necessary to use a large member, and it is necessary to increase the size of the oil separator. In addition, the pressure loss is increased and the compression efficiency of the compressor is reduced.

Accordingly, it is an object of the present invention to provide a compressor with high lubricating oil separation capability without the addition of additional components. Another object is to maintain a high lubricating oil separation capacity regardless of the operating state of the compressor, that is, regardless of the rotation speed.

[0008]

In order to achieve the above object, the present invention increases the surface shape of a wall provided in an oil separation chamber of a compressor or an oil separator as compared with a smooth surface in its surface area. It is characterized in that it is formed as follows. This increases the surface area of the wall that the lubricating oil mixed in the fluid introduced into the separation chamber can contact, thus increasing the amount of the lubricating oil mixed in the fluid physically contacting the surface of the wall, The amount of lubricating oil trapped on the wall surface increases. Therefore,
The above characteristics have the effect of improving the lubricating oil separation ability of the oil separation chamber of the compressor or the oil separator.

It is preferable to increase the surface area of the wall by providing a plurality of irregularities on the surface of the wall provided in the oil separation chamber. As a result, a turbulent flow is generated in the vicinity of the surface of the wall of the separation chamber, which makes it easier for the lubricating oil in the fluid to contact the surface of the wall and further increases the amount of lubricating oil trapped on the surface of the wall. Play. Further, forming unevenness on the surface of the wall of the oil separation chamber leads to a decrease in flow resistance near the surface of the wall of the oil separation chamber due to turbulent flow. In compressors or oil separators, etc. that are used to separate lubricating oil from fluid, for example, the compressor is operating in a low rotation range, and the fluid introduced into the oil separation chamber is given sufficient swirling speed. When it is not possible, it is particularly effective for improving the lubricating oil separation ability.

Further, the surface shape of the inner wall of the oil separation chamber may be formed so as to increase the surface area thereof, and the baffle plate provided at the position where the fluid discharged from the compression mechanism collides with the oil separation chamber separately. May be formed so that its surface area increases. As a result, the lubricating oil separation capacity can be improved simply by processing the surface of the component already installed to separate the lubricating oil from the fluid into a shape that increases the surface area of the surface compared to a smooth surface. On the other hand, it is possible to suppress the additional cost without adding new parts.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view showing an embodiment of a compressor having a separation chamber according to the present invention, and FIG. 2 is a line II in FIG.
FIG. 6 is a sectional view taken along line II.

The present invention is directed to any compressor of a type that uses lubricating oil to smoothly slide between a fixed part and a movable part forming a compression space, such as a reciprocating compressor and a rotary compressor. ,
The present invention can be applied to scroll type compressors and oil separators used with them, but here, the present invention will be described by taking an embodiment in which the present invention is applied to a scroll type compressor used in a vehicle air conditioner as an example. explain.

In the scroll compressor 10 shown in FIG. 1, the housing 12 has a front housing 14 and a spiral body 16, and is fixed to the fixed scroll 18 and the fixed scroll 18 fixed to the front housing 14. And rear housings 20 and 20a. In a space formed between the front housing 14 and the fixed scroll 18, a movable scroll 24 having a spiral body 22 and rotating with respect to the fixed scroll 18 is arranged.

Fixed scroll 18 and movable scroll 2
Reference numeral 4 forms a compression space 26 between the spiral bodies 16 and 22 by engaging the spiral bodies 16 and 22, and the compression space 26 is compressed together with the shaft 30 rotatably supported by the front housing 14 via a rolling bearing 28. It constitutes the mechanism. A suction chamber 32 is formed on the outer side in the radial direction of the movable scroll 24, and a fluid to be compressed such as a refrigerant gas or air is supplied to the suction chamber 32 from the outside of the compressor 10.

One end of the shaft 30 is connected to an external drive source such as a vehicle engine (not shown), and is rotationally driven by the output of the external drive source. A drive key portion 36 is formed at the other end of the shaft 30 (on the side of the movable scroll 24) so as to be eccentric from the rotation axis 34 of the shaft 30 by a predetermined amount, and a bush 38 is arranged outside the drive key portion 36. Has been done. Further, the movable scroll 24 is rotatably connected to the bush 38 via a needle bearing 40.

A rotation preventing mechanism 42 is provided between the movable scroll 24 and the front housing 14 to prevent the movable scroll 24 from rotating around the bush 38 when the shaft 30 is rotated. ing. Therefore, when the shaft 30 is rotated, the movable scroll 24 does not rotate about its own axis but only revolves. Further, the bush 38 is provided with a balance weight 44 so as to cancel the centrifugal force caused by the revolution of the movable scroll 24.

Fixed scroll 18 and rear housing 2
0 forms a discharge chamber 46 between them, and the fluid compressed in the compression space 26 of the compression mechanism is fixed scroll 18
Through the discharge port 48 formed at the approximate center of the discharge chamber 4
6 is discharged. The discharge port 48 is provided with a discharge valve 50 in order to prevent the fluid from flowing back from the discharge chamber 46 into the compression space 26, and a stopper for restricting the maximum opening degree of the discharge valve 50. 52 is provided.

In the rear housings 20 and 20a, there is further formed an oil separation chamber 54 which functions as an oil separator for separating the lubricating oil mixed in the fluid discharged into the discharge chamber 46, and is formed in the upper part. It communicates with an external circuit such as a condenser via a connected outlet pipe 56, and also communicates with a compression mechanism via a return passage 58 connected to the lower portion.

Referring to FIGS. 1 and 2, the oil separation chamber 54 in the present embodiment has a substantially cylindrical shape whose central axis extends vertically in the drawings, and an inner wall 60 of the oil separation chamber 54.
It communicates with the discharge chamber 46 through the inlet 62 formed in the. Further, the introduction port 62 is arranged so that the fluid introduced from here may flow in a direction substantially tangential to the cylindrical inner wall 60 of the oil separation chamber 54. Therefore, the fluid mixed with the lubricating oil and discharged from the compression space 26 to the discharge chamber 46 is introduced into the oil separation chamber 54 with a sufficient flow velocity by the passage area being restricted by the introduction port 62 to be introduced into the oil separation chamber 54. It is swung along the inner wall 60 of the separation chamber 54. As a result, the lubricating oil mixed in the fluid comes into contact with and is captured by the inner wall 60 of the oil separation chamber 54 by the centrifugal action, and is separated from the fluid.

Further, according to the present invention, the surface shape of the wall of the oil separation chamber 54 (inner wall 60 in the present embodiment) improves the lubricating oil separation ability for separating and removing the lubricating oil from the fluid. It is formed so that the surface area of the wall is increased as compared with the case where the surface is smooth. In the embodiment shown in FIGS. 1 and 2, the inner wall of the oil separation chamber 54 is formed by forming a plurality of irregular irregularities on the surface of the inner wall 60 of the oil separation chamber 54, such as by providing beads or depressions. The surface area of 60 is increased. Of course, the oil separation chamber 5
Unevenness may be formed on the surface of the inner wall 60 of No. 4. For example,
It is also possible to create the oil separation chamber 54 of the rear housing 20, 20a by casting and use the casting surface at that time as it is.

By increasing the surface area of the inner wall 60 of the oil separation chamber 54 in this way, the mist-like lubricating oil mixed with the fluid is introduced into the oil separation chamber 54 and flows along the inner wall 60. In doing so, the amount of physical contact with the surface of the inner wall 60 of the oil separation chamber 54 increases, so more than in the conventional oil separation chamber 54 where the surface of the inner wall 60 is smooth. It becomes possible to trap the amount of lubricating oil on the surface of the inner wall 60.

Further, since a plurality of irregularities are formed on the surface of the inner wall 60 of the oil separation chamber 54, when the fluid flows, turbulent flow occurs near the surface of the inner wall 60. As a result, since the mist-like lubricating oil mixed in the fluid easily contacts or collides with the surface of the inner wall 60 of the oil separation chamber 54, the effect of increasing the amount of the lubricating oil trapped on the surface of the inner wall 60 is obtained. Play.

Further, due to the turbulent flow, the inner wall 60
The flow resistance in the vicinity of the surface is significantly reduced, and the velocity attenuation when the fluid moves along the inner wall 60 is reduced. As a result, when the lubricating oil is separated from the fluid by utilizing the centrifugal action as in the embodiment, the swirling speed applied to the fluid when being introduced from the introduction port 62 is less likely to decrease. , The fluid travels a longer distance to increase the number of times the mist-like lubricating oil collides with or contacts the inner wall 60, and also maintains sufficient centrifugal action to be trapped on the inner wall 60 and separated from the fluid. The amount of lubricating oil that will be consumed will increase. Therefore, when the compressor 10 is operated in a low rotation speed range such as when the load is low, the fluid introduced into the oil separation chamber 54 does not have a sufficient swirling speed, and it is difficult to obtain a sufficient centrifugal separation action, The present invention is particularly advantageous.

In the present embodiment, the oil separation chamber 54 is
The lubricating oil separated and collected from the fluid can be stored in the lower part of the oil separation chamber 54 and also serves as an oil storage chamber. Also,
In the present embodiment, the oil separation chamber 54 communicates with the suction chamber 32 through the return passage 58, and the lubricating oil separated and collected in the oil separation chamber 54 returns to the suction chamber 32 and is required. Lubricating oil is mixed in the fluid in the suction chamber 32 in accordance with the amount, whereby the compression mechanism is lubricated and the compression space 26 is sealed.

Next, the operation of the compressor 10 of this embodiment will be described.

When the output of an external drive source such as a vehicle engine is transmitted to the shaft 30 and the shaft 30 is rotationally driven, the movable scroll 24 is rotated via the drive key portion 36 as the shaft 30 rotates. At this time, the movable scroll 24 does not rotate around the bush 38 by the rotation preventing mechanism 42, and the rotation axis 34 of the shaft 30 does not rotate.
Only the revolution of the surroundings is performed.

A fluid such as refrigerant gas or air is supplied from the outside of the compressor 10 to the suction chamber 32 formed on the outer side in the radial direction of the movable scroll 24, and the lubricating oil supplied through the return path 58 is sucked into the suction chamber. It is mixed with the fluid at 32. The lubricating oil may be mixed in before being supplied to the suction chamber 32.

The movable scroll 24 is the fixed scroll 18.
When the orbiting motion is performed, the fluid mixed with the lubricating oil is sucked from the suction chamber 32 into the compression space 26 formed by the movable scroll 24 and the fixed scroll 18, and is compressed in the compression space 26. The compression space 26 is moved from the outer side position of the fixed scroll 18 which is in communication with the suction chamber 32 by the orbiting of the movable scroll 24 to the fixed scroll 1.
As it moves toward the center of 8 in a spiral shape, it is gradually contracted and the fluid inside is compressed. When the compression space 26 reaches the center of the fixed scroll 18,
The fluid compressed to a high pressure is discharged into the discharge chamber 46 from the discharge port 48 provided in the central portion of the fixed scroll 18.

The fluid discharged into the discharge chamber 46 is narrowed in passage area by a relatively small-diameter inlet 62 leading to the oil separation chamber 54 to have a sufficient flow velocity, and then the inner wall 60 of the oil separation chamber 54. It is introduced in the tangential direction and spirally moves along the inner wall 60 of the oil separation chamber 54. At this time, the mist-like lubricating oil mixed in the fluid is separated from the fluid by the centrifugal separation action by the swirling.

Further, the inner wall 60 of the oil separation chamber 54 is formed with a plurality of irregularities to generate a turbulent flow near the surface of the inner wall 60 and to increase the surface area where the fluid can contact the inner wall 60. Therefore, the mist-like lubricating oil mixed in the fluid easily contacts or collides with the inner wall 60,
A greater amount of lubricating oil may be trapped on the inner wall 60 and separated from the fluid as compared to the smooth surface inner wall 60.

Therefore, in the compressor 10 of this embodiment, the compressor is operated in the low rotation speed range, and the oil separation chamber 5
Even if the fluid introduced into No. 4 cannot be provided with a sufficient flow rate and a sufficient centrifugal separation action cannot be expected, it is possible to exert a sufficient lubricating oil separation ability.

The fluid from which the lubricating oil has been separated in the oil separation chamber 54 is sent to an external circuit such as a condenser through an outlet pipe 56 connected to the upper portion of the oil separation chamber 54. On the other hand, the separated lubricating oil is subjected to the action of gravity to the inner wall 60 of the oil separation chamber 54.
Flow downwards along and collected in the lower part of the oil separation chamber 54,
Be stored. Then, the oil is returned to the suction chamber 32 of the compression mechanism through the return passage 58 connected to the lower portion of the oil separation chamber 54.

As described above, the embodiment in which the present invention is applied to the surface shape of the inner wall 60 of the oil separation chamber 54 which is formed integrally with the scroll compressor 10 and separates the lubricating oil from the fluid by utilizing the centrifugal separation action is described. The principle of the invention has been described by way of example. However, the present invention is not limited to the above embodiment.

For example, the oil separation chamber 54 is not only provided integrally with the compressor at the outlet side of the compression space 26 as in the above embodiment, but also as a separate device between the compressor 10 and the condenser ( It may be provided as an oil separator).

The present invention is also disclosed in JP-A-5-199571.
As described in the publication, by causing the fluid introduced into the oil separation chamber 54 to collide with the baffle plate 64, the surface of the baffle plate 64 captures the mist-like lubricating oil mixed in the fluid, Oil separator 5 for separating lubricating oil from fluid
4 is also applicable. In this case, as shown in FIG. 3, the surface shape of the baffle plate 64 provided in the oil separation chamber 54 as a wall for bringing the fluid into contact and capturing and removing the lubricating oil mixed in the fluid is changed. The surface area of the baffle plate 64 may be increased by changing it, for example, by forming a plurality of irregularities on the surface of the baffle plate.

Further, in the embodiment, the scroll type compressor 10 is exemplified, but the present invention can be applied to any other type of compressor such as a reciprocating compressor and a rotary type compressor, and the compressor has a low rotation range. It is especially suitable for compressors used in commercial air conditioners, which are often operated in, and vehicle air conditioners in which the operating load fluctuates significantly.

[Brief description of drawings]

1 is a cross-sectional view showing an embodiment of a compressor including an oil separation chamber according to the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view showing a second embodiment of the oil separation chamber according to the present invention.

[Explanation of symbols]

10 ... Compressor 12 ... Housing 14 ... Front housing 18 ... Fixed scroll 20 ... Rear housing 20a ... rear housing 24 ... Movable scroll 26 ... Compressed space 30 ... Shaft 54 ... Oil separation chamber 58 ... Return passage 60 ... Inner wall 62 ... Inlet 64 ... Baffle plate

Claims (5)

[Claims] 1. A housing is provided with a compression mechanism for sucking and compressing a fluid, and an oil separation chamber for separating the lubricating oil mixed in the fluid discharged from the compression mechanism from the fluid, and the compression mechanism is used for compression. The fluid is introduced into the oil separation chamber, and the lubricating oil mixed in the fluid is brought into contact with the wall provided in the oil separation chamber to capture the lubricating oil on the wall, and the lubricating oil is separated. In the compressor that discharges fluid from the oil separation chamber, by forming the surface shape of the wall so that the surface area thereof increases, the lubricating oil mixed in the fluid introduced into the oil separation chamber is the wall. A compressor characterized by increasing the amount captured on the surface of. 2. The compressor according to claim 1, wherein the surface area of the wall is increased by providing a plurality of irregularities on the surface of the wall. 3. The wall is an inner wall of the oil separation chamber,
The compressor according to claim 1 or 2. 4. The compressor according to claim 1, wherein the wall is a baffle plate provided at a position where the fluid discharged from the compression mechanism collides in the oil separation chamber. 5. An oil separation chamber for separating the lubricating oil from the fluid mixed with the lubricating oil is provided, the fluid compressed by a compressor is introduced into the oil separation chamber, and the lubricating oil mixed in the fluid is introduced into the oil separating chamber. An oil separator that captures lubricating oil on the wall and separates the lubricating oil from the fluid by contacting the wall provided in the oil separation chamber, wherein the surface shape of the wall is formed so that its surface area increases. By doing so, the amount of the lubricating oil mixed in the fluid introduced into the oil separation chamber is increased on the surface of the wall to increase the amount of the oil separator.