U.S. patent application number 12/257867 was filed with the patent office on 2010-04-29 for compressor with improved oil separation.
Invention is credited to Kanwal Bhatia, Rodney Callahan, Thomas Finn, John Richard Mikkelsen, Michael Theodore, JR..
Application Number | 20100101269 12/257867 |
Document ID | / |
Family ID | 42116163 |
Filed Date | 2010-04-29 |
United States Patent
Application |
20100101269 |
Kind Code |
A1 |
Theodore, JR.; Michael ; et
al. |
April 29, 2010 |
COMPRESSOR WITH IMPROVED OIL SEPARATION
Abstract
An oil separator for a fluid compressor is disclosed. The oil
separator includes a housing having a generally cylindrical cavity
formed therein. A wall is disposed in the cavity to form an inlet
side of the cavity and an outlet side of the cavity. A conduit
extends through the wall and provides a fluid communication path
between the inlet side and the outlet side of the cavity. The inlet
side of the cavity facilitates the separation of an oil from a
fluid, wherein the separated oil is returned to an oil reservoir
formed in the housing, and the fluid is provided substantially free
of oil to an associated refrigeration circuit.
Inventors: |
Theodore, JR.; Michael;
(Plymouth, MI) ; Bhatia; Kanwal; (Canton, MI)
; Finn; Thomas; (Plymouth, MI) ; Callahan;
Rodney; (Novi, MI) ; Mikkelsen; John Richard;
(Novi, MI) |
Correspondence
Address: |
FRASER CLEMENS MARTIN & MILLER LLC
28366 KENSINGTON LANE
PERRYSBURG
OH
43551
US
|
Family ID: |
42116163 |
Appl. No.: |
12/257867 |
Filed: |
October 24, 2008 |
Current U.S.
Class: |
62/470 |
Current CPC
Class: |
F04B 53/18 20130101;
F04B 39/0207 20130101; F04B 39/04 20130101 |
Class at
Publication: |
62/470 |
International
Class: |
F25B 43/02 20060101
F25B043/02 |
Claims
1. An oil separator for a fluid compressor comprising: a housing
having a cavity formed therein; a wall disposed in the cavity to
divide the cavity into an inlet side and an outlet side, the inlet
side including a fluid inlet channel and at least one fluid drain
channel, and the outlet side including a fluid outlet channel,
wherein the inlet side of the cavity facilitates the separation of
an oil from a fluid; and a conduit extending through the wall
providing a fluid communication path between the inlet side and the
outlet side of the cavity.
2. The oil separator according to claim 1, wherein the cavity is
generally cylindrical.
3. The oil separator according to claim 1, wherein a surface of the
cavity is textured to maximize a surface area thereof.
4. The oil separator according to claim 1, wherein the fluid inlet
channel in the inlet side of the cavity is in fluid communication
with a discharge port of the fluid compressor.
5. The oil separator according to claim 1, wherein the fluid inlet
channel in the inlet side of the cavity is formed adjacent the
wall.
6. The oil separator according to claim 1, wherein the fluid inlet
channel in the inlet side of the cavity is formed to facilitate a
rotational fluid flow in the cavity.
7. The oil separator according to claim 1 wherein one end of the
conduit extends from the wall into the inlet side of the cavity and
an opposite end of the conduit extends from the wall into the
outlet side of the cavity.
8. The oil separator according to claim 7, wherein the conduit
includes a bell mouth formed at the one end of the conduit
extending into the inlet side of the cavity.
9. The oil separator according to claim 1, wherein the conduit is
concentric with the cavity.
10. The oil separator according to claim 1, wherein the fluid
outlet channel formed in the outlet side of the cavity is adapted
to be in fluid communication with a refrigeration circuit.
11. A fluid compressor comprising: a housing having a discharge
port and at least one oil reservoir formed therein; a generally
cylindrical cavity formed in the housing forming an oil separator,
the oil separator further comprising: a wall disposed in the cavity
to divide the cavity into an inlet side and an outlet side, the
inlet side including a fluid inlet channel providing fluid
communication between the discharge port and the inlet side, and at
least one fluid drain channel providing fluid communication between
the at least one oil reservoir and the inlet side, the outlet side
including a fluid outlet channel adapted to provide fluid
communication between the outlet side and a refrigeration circuit,
wherein the inlet side of the cavity facilitates the separation of
an oil from a fluid; and a conduit extending through the wall
providing a fluid communication path between the inlet side and the
outlet side of the cavity.
12. The fluid compressor according to claim 11, wherein the oil
reservoir is formed to surround at least a portion of the housing
of the compressor.
13. The fluid compressor according to claim 11, wherein an orifice
is formed in the housing of the compressor to provide a fluid
communication path between the oil reservoir and an interior of the
compressor.
14. The fluid compressor according to claim 11, wherein the fluid
inlet channel in the inlet side of the cavity is formed adjacent
the wall.
15. The fluid compressor according to claim 11, wherein the fluid
inlet channel in the inlet side of the cavity is formed to
facilitate a rotational fluid flow in the cavity.
16. The fluid compressor according to claim 11, wherein a surface
of the cavity is textured to maximize a surface area thereof.
17. The fluid compressor according to claim 11, including a bell
mouth formed at an end of the conduit disposed in the inlet side of
the cavity.
18. A method for separating a lubricant from a refrigerant in a
fluid compressor comprising the steps of: providing a housing for
the compressor having a generally cylindrical cavity, a discharge
port, and at least one oil reservoir formed therein; providing a
wall to divide the cavity into an inlet side and an outlet side,
the inlet side including a fluid inlet channel providing fluid
communication between the discharge port and the inlet side of the
cavity, and at least one fluid drain channel providing fluid
communication between the at least one oil reservoir and the inlet
side of the cavity, the outlet side including a fluid outlet
channel providing fluid communication between the outlet side of
the cavity and an associated refrigeration circuit; providing a
conduit extending through the wall providing a fluid communication
path between the inlet side and the outlet side of the cavity;
causing a refrigerant-oil fluid mixture to flow from the discharge
port, through the fluid inlet channel, and into the inlet side of
the cavity, wherein the fluid inlet channel is formed to facilitate
a rotational flow of the refrigerant-oil fluid mixture in the
cavity to apply a centrifugal force to separate the oil from the
refrigerant. causing the separated oil to pool in the inlet side
and flow through the fluid drain channel to the at least one oil
reservoir, and causing the refrigerant to flow from the inlet side
of the cavity through the conduit into the outlet side of the
cavity, and through the fluid outlet channel to the associated
refrigeration circuit.
19. The method according to claim 18, further comprising the step
of providing a textured surface to a surface of the inlet side of
the cavity to maximize a surface area thereof.
20. The method according to claim 18, further comprising the step
of forming a bell mouth at an end of the conduit extending into the
inlet side of the cavity.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a compressor, and more
particularly to an oil separator for a compressor adapted to
separate lubricating oil from a gaseous medium.
BACKGROUND OF THE INVENTION
[0002] Compressors used in refrigeration and air conditioning
systems such as swashplate type compressors and scroll compressors,
for example, typically include a lubricating oil mist suspended in
a gaseous refrigerant medium. Such compressors are often employed
in automotive air conditioning systems. In a typical automotive air
conditioning system, the oil-refrigerant mixture enters the
compressor through a suction port and is compressed therein. The
compressed, high pressure oil-refrigerant mixture exits the
compressor through a discharge port to travel through a
refrigeration circuit before returning to the suction port to begin
another cycle through the compressor and the refrigeration
circuit.
[0003] Although the oil circulates through the entire refrigeration
circuit, it is only needed in the compressor to lubricate the
moving parts therein. Oil that remains suspended in the refrigerant
as it travels throughout the refrigeration circuit can reduce the
performance of the refrigeration circuit. For example, oil that
travels through a heat exchanger in the refrigeration circuit is
known to wet internal surfaces of the heat exchanger. Oil disposed
on the internal surfaces of the heat exchanger reduces the heat
transfer rate between the heat exchanger an the refrigerant.
Accordingly, the compressor and other components of the
refrigeration or the air conditioning system must have additional
capacity to overcome the reduced heat transfer rate caused by oil
flowing throughout the refrigeration circuit.
[0004] Also, oil that remains suspended in the refrigerant flowing
through the refrigeration circuit is not available to lubricate the
moving parts of the compressor. The compressor is susceptible to
increased wear and seizure potential as a result of the reduced
amount of available lubricating oil.
[0005] To combat these problems, an oil separator can be added to
the compressor. Such an oil separator is typically positioned
between the discharge port and a condenser inlet. The oil separator
functions to separate the suspended oil from the gaseous
refrigerant and militate against the oil from exiting the
compressor and circulating through the refrigeration circuit.
However, prior art oil separators such as U.S. Pat. No. 6,551,072
to Ota et al. and U.S. Pat. No. 7,281,913 to Oiwake typically
increase the overall size of the compressor, limit the available
positions for mounting the compressor, and do not significantly
reduce the amount of oil required to adequately lubricate the
compressor.
[0006] It would be desirable to produce an oil separator for a
fluid compressor, wherein a space requirement is minimized, and an
oil separation efficiency and available mounting positions of the
compressor are maximized.
SUMMARY OF THE INVENTION
[0007] Compatible and attuned with the present invention, an oil
separator for a fluid compressor, wherein a space requirement is
minimized, and an oil separation efficiency and available mounting
positions of the compressor are maximized, has surprisingly been
discovered.
[0008] In one embodiment, an oil separator for a fluid compressor
comprises a housing having a cavity formed therein; a wall disposed
in the cavity to divide the cavity into an inlet side and an outlet
side, the inlet side including a fluid inlet channel and at least
one fluid drain channel, and the outlet side including a fluid
outlet channel, wherein the inlet side of the cavity facilitates
the separation of an oil from a fluid; and a conduit extending
through the wall providing a fluid communication path between the
inlet side and the outlet side of the cavity.
[0009] In another embodiment, a fluid compressor comprises a
housing having a discharge port and at least one oil reservoir
formed therein; a generally cylindrical cavity formed in the
housing forming an oil separator, the oil separator further
comprising: a wall disposed in the cavity to divide the cavity into
an inlet side and an outlet side, the inlet side including a fluid
inlet channel providing fluid communication between the discharge
port and the inlet side, and at least one fluid drain channel
providing fluid communication between the at least one oil
reservoir and the inlet side, the outlet side including a fluid
outlet channel adapted to provide fluid communication between the
outlet side and a refrigeration circuit, wherein the inlet side of
the cavity facilitates the separation of an oil from a fluid; and a
conduit extending through the wall providing a fluid communication
path between the inlet side and the outlet side of the cavity.
[0010] A method for separating a lubricant from a refrigerant in a
fluid compressor comprising the steps providing a housing for the
compressor having a generally cylindrical cavity, a discharge port,
and at least one oil reservoir formed therein; providing a wall to
divide the cavity into an inlet side and an outlet side, the inlet
side including a fluid inlet channel providing fluid communication
between the discharge port and the inlet side of the cavity, and at
least one fluid drain channel providing fluid communication between
the at least one oil reservoir and the inlet side of the cavity,
the outlet side including a fluid outlet channel providing fluid
communication between the outlet side of the cavity and an
associated refrigeration circuit; providing a conduit extending
through the wall providing a fluid communication path between the
inlet side and the outlet side of the cavity; causing a
refrigerant-oil fluid mixture to flow from the discharge port,
through the fluid inlet channel, and into the inlet side of the
cavity, wherein the fluid inlet channel is formed to facilitate a
rotational flow of the refrigerant-oil fluid mixture in the cavity
to apply a centrifugal force to separate the oil from the
refrigerant; causing the separated oil to pool in the inlet side
and flow through the fluid drain channel to the at least one oil
reservoir, and causing the refrigerant to flow from the inlet side
of the cavity through the conduit into the outlet side of the
cavity, and through the fluid outlet channel to the associated
refrigeration circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The above, as well as other objects and advantages of the
invention, will become readily apparent to those skilled in the art
from reading the following detailed description of the preferred
embodiment of the invention when considered in the light of the
accompanying drawings in which:
[0012] FIG. 1 is a perspective view of a compressor showing an oil
separator in section in accordance with an embodiment of the
invention;
[0013] FIG. 2 is an enlarged fragmentary perspective view of the
compressor of FIG. 1 with the oil separator shown in section along
line 2-2 in FIG. 1;
[0014] FIG. 3 is an enlarged fragmentary perspective view of the
compressor of FIG. 1 with the oil separator shown in section along
line 3-3 in FIG. 1;
[0015] FIG. 4 is an enlarged fragmentary perspective view of the
compressor of Fig.1 with the oil separator shown in section along
line 4-4 in FIG. 1; and
[0016] FIG. 5 is an enlarged fragmentary perspective view of an oil
separator according to another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] The following detailed description and appended drawings
describe and illustrate various exemplary embodiments of the
invention. The description and drawings serve to enable one skilled
in the art to make and use the invention, an are not intended to
the scope of the invention in any manner. In respect of he methods
disclosed, the steps presented are exemplary in nature, and thus,
the order of t e steps is not necessary or critical.
[0018] FIGS. 1-4 show a fluid compressor 1 including an oil
separator 10. The compressor 1 can be any type of fluid compressor
such as a swashplate type compressor as disclosed in U.S. Pat. No.
6,431,053, hereby incorporated herein by reference in its entirety,
or a scroll type compressor as disclosed in U.S. Pat. Nos.
6,543,243 and 6,382,941, each of which is hereby incorporated
herein by reference in its entirety. Other compressors may be used
as desired. In general, the compressor 1 includes a multi-piece
housing 2 having a suction port (not shown) and a discharge port 4.
The suction port provides a fluid communication path for a fluid to
enter the compressor 1 from a refrigeration circuit (not shown) and
be received by a means for compressing a fluid (not shown) disposed
within an interior of the housing 2. The discharge port 4 provides
a fluid communication path for the compressed fluid to exit the
means for compressing and flow back into the refrigeration circuit
through an outlet channel 9. In the embodiment shown, the fluid is
a refrigerant including a lubricating oil for use in a
refrigeration system (not shown) such as a heating, ventilating,
and air conditioning system for a vehicle, for example. It should
be understood that the refrigerant and the oil can be any suitable
refrigerant and oil, as desired.
[0019] A pair of oil reservoirs 6 is formed in the housing 2 of the
compressor 1. In the illustrated embodiment, the oil reservoirs 6
are formed to surround at least a portion of the housing 2 to form
a pair of generally lung shaped cavities for holding a liquid
lubricating oil for lubricating moving components disposed within
the housing 2 of the compressor 1. An orifice 8 is disposed between
each oil reservoir 6 and the interior of the housing 2 to
facilitate the flow of the liquid oil from the oil reservoir 6 to
the interior of the housing 2, and to minimize a gas recirculation
through the compressor between the oil separator 10 and the
interior of the housing 2 of the compressor 1. It should be
understood that a single oil reservoir can be provided, or more
than two oil reservoirs can be provided, as desired.
[0020] The oil separator 10 has a generally cylindrical cavity 12
formed in the housing 2 thereof. It should be understood that other
shapes can be employed for the cavity 12 as desired. A longitudinal
axis of the cylindrical cavity 12 is substantially parallel with a
longitudinal axis of the compressor 1. It should be understood that
the oil separator 10 can be formed as a separate component that is
attached to the housing 2 of the compressor 1.
[0021] A sleeve 14 is disposed within the cavity 12 that includes a
radially inwardly extending wall 16 to divide the cavity 12 between
an inlet side 18 and an outlet side 20. It should be understood
that the sleeve 14 can be disposed within the cavity at a variety
of locations to provide a desired volume to the inlet side 18 and
the outlet side 20, respectively. As illustrated in FIG. 5, a
textured finish 29 can be formed on an interior surface of the
inlet side 18 of the cylindrical cavity 12. The textured finish 29,
such as a knurled surface, an anodized surface, or the like,
increases a surface area of the interior surface, which maximizes
an oil separation potential of the oil separator 10.
[0022] A conduit 22 such as a tube, for example, is provided that
extends through the wall 16 having one end 24 disposed in the inlet
side 18 and an opposite end 26 dispose in the outlet side 20 of the
cylindrical cavity 12. The conduit 22 provides fluid communication
between the inlet side 18 and the outlet side 20 of the cavity 12.
The conduit 22 passes through the wall 16 substantially at a center
point thereof to position the conduit 22 substantial concentric
with the interior surface forming the cavity 12. It should be
understood that a distance between the one end 24 of the conduit 22
and the wall 16 can be any distance, as desired. Additionally, a
distance between the opposite end 26 of the conduit 22 and the wall
16 can be any selected distance to achieve a desired expansion
characteristic of the fluid flowing therethrough. Further, a bell
mouth 28 can be formed on the one end 24 of the conduit 22 as
illustrated in FIG. 5. The bell mouth 28 facilitates the flow of
the fluid into the conduit 22 to minimizes frictional losses and an
associated pressure drop in the fluid flowing therethrough, which
maximizes an efficiency of the compressor 1. Additionally, the bell
mouth 28 causes the fluid to flow adjacent the interior surface
forming the cavity 12 as the fluid flows past the bell mouth 28
prior to flowing into the conduit 22.
[0023] An inlet channel 30 is formed in the housing 2 that provides
fluid communication between the discharge port 4 of the compressor
1 and the inlet side 18 of the oil separator 10. The inlet channel
30 is formed at an angle in respect of the interior surface of the
inlet side 18 of the oil separator 10 to facilitate creation of a
vortex fluid flow path therein. Favorable results have been
obtained by locating an opening to the inlet channel 30 adjacent
the wall 16 to maximize a distance between the opening to the inlet
channel 30 and the one 24 of the conduit 22.
[0024] A pair of oil drain channels 32 is formed in the housing 2
that provides a fluid communication path for the liquid oil to flow
from the inlet side 18 to the oil reservoirs 6. The oil drain
channels 32 can be formed at a desired location to facilitate the
flow of the liquid oil therethrough. Favorable results have been
obtained by locating an opening of the drain channels 32 adjacent a
bottom most portion of the inlet side 18 of the oil separator 10 in
respect of a selected mounting position of the compressor 1. It
should be understood that a single oil drain channel can be formed
in the housing 2 that provides a fluid communication path between
the inlet side 18 and one or more oil reservoirs 6.
[0025] An outlet channel 34 is formed in the housing 2 to provide a
fluid communication path for the compressed refrigerant gas to flow
from the outlet side 20 of the oil separator 10 and exit the
compressor through the outlet channel 9 to the refrigeration
circuit. It should be understood that an opening to the outlet
channel 34 can be located at a desired location on the inner
surface forming the outlet side 20 of the oil separator 10.
[0026] In operation, a refrigerant-oil fluid mixture flows through
the suction chamber of the compressor 1 and enters the means for
compressing the fluid disposed within the housing 2 of the
compressor 1. The fluid is compressed and exhausted from the means
for compressing to the discharge port 4. The fluid flows through
the discharge port 4 and the inlet channel 30 into the inlet side
18 of the oil separator 10. The inlet channel 30 causes the fluid
to enter the inlet side 18 of the oil separator 10 at in angle in
respect of the interior surface of the inlet side 18 of the oil
separator 10. Thus, a substantially vortex type flow of the fluid
is created within the inlet side 18 of the oil separator 10,
wherein the fluid repeatedly swirls around the conduit 22 as it
flows from the inlet channel 30 toward the one end 24 of the
conduit 22. The swirling movement of the fluid applies a
centrifugal force on the oil in the fluid, thereby separating the
liquid oil from the gas refrigerant. The textured surface 29
forming the inlet side 18 of the cavity 12 maximizes a surface area
thereof to maximize the oil separating capability of the oil
separator 10. The separated oil collects on the interior surface of
the inlet side 18 of the cavity 12 and pools at the bottom most
portion thereof.
[0027] The oil drain channels 32 are formed in the housing 2 of the
compressor 1 having an opening to the oil drain channels 32
adjacent the bottom most portion of the cavity 12. The pooled oil
flows through the drain channels 32 into the reservoirs 6. The oil
can then flow from the reservoirs 6, through the orifices 8, and
into the interior of the housing 2 for lubricating any moving parts
disposed therein. The orifices 8 militate against a recirculation
of the refrigerant through the oil drain channels 32 to the
interior of the housing 2 of the compressor 1.
[0028] The oil is substantially separated from the refrigerant in
the inlet side 18 of the oil separator 10. The refrigerant,
substantially free of oil, flows from the inlet side 18 through the
conduit 22 into the outlet side 20 of the oil separator 10. The
bell mouth 28, illustrated in FIG. 5, can be formed on the end 24
of the conduit 22 to further facilitate the flow of the refrigerant
from the inlet side 18 into the conduit 22. In particular, the bell
mouth 28 is adapted to tune the flow of the refrigerant to minimize
frictional losses, which maximizes the coefficient of performance
of the compressor 1. Additionally, the bell mouth 28 causes the
fluid to flow adjacent the interior surface forming the cavity 12
as the fluid flows past the bell mouth 28 prior to flowing into the
conduit 22, which maximizes a contact between the fluid and the
interior surface forming the cavity 12. The distance between the
wall 16 and the end 26 of the conduit 22 is selected to achieve a
desired expansion characteristic to the oil separator 10 for the
refrigerant as it flows into the outlet side 20 of oil separator
10. The refrigerant exits the outlet side 20 of the oil separator
through the outlet channel 34 to exit the compressor through the
outlet channel 9 and flow into the refrigeration circuit.
[0029] It should be understood that the inlet side 18, outlet side
20, and conduit 22 cooperate to muffle the flow of the compressed
refrigerant as it exits the compressor. The expansion and
contraction of the refrigerant as it flows through the oil
separator 12 enables the oil separator 10 act as a tunable muffler
that can be adapted to minimize noise, vibration, and harshness
(NVH) emanating from the compressor 1.
[0030] The forming of the oil reservoirs 6 and the oil separator 10
integrally with the housing 2 of the compressor 1 provides a
compressor that can be configured to a number of applications. For
example, the compressor 1 can be mounted at a plurality of
positions such as the oil separator 10 located at a top most
location in respect of the compressor 1, or can be mounted wherein
the compressor 1 is rotated about its longitudinal axis to position
the oil separator 10 forty-five degrees from the top most location.
The oil reservoirs 6 and the oil separator 10 enable the compressor
1 to be mounted in a plurality of such positions without
substantially affecting the performance of the oil separator 10.
Additionally, it should be understood that the oil drain channels
34 can be formed at selected locations in the housing 2 to position
the openings to the oil drain channels 34 at an optimized position
for the intended mounting position of the compressor 1.
[0031] The fluid compressor 1 described herein includes an oil
separator 10 and associated oil reservoirs 6 which minimize a space
requirement for the compressor 1 while an oil separation efficiency
and available mounting positions of the compressor 1 are
maximized.
[0032] From the foregoing description, one ordinarily skilled in
the art can easily ascertain the essential characteristics of this
invention and, without departing from the spirit and scope thereof,
can make various changes and modifications to the invention to
adapt it to various usages and conditions.
* * * * *