U.S. patent application number 16/608564 was filed with the patent office on 2020-06-18 for compressor.
This patent application is currently assigned to Brose Fahrzeugteile GmbH & Co. Kommanditgesellschaft, Wurzburg. The applicant listed for this patent is Brose Fahrzeugteile GmbH & Co. Kommanditgesellschaft, Wurzburg. Invention is credited to Bjorn FAGERLI, Budi RINALDI.
Application Number | 20200191146 16/608564 |
Document ID | / |
Family ID | 62044746 |
Filed Date | 2020-06-18 |
![](/patent/app/20200191146/US20200191146A1-20200618-D00000.png)
![](/patent/app/20200191146/US20200191146A1-20200618-D00001.png)
![](/patent/app/20200191146/US20200191146A1-20200618-D00002.png)
![](/patent/app/20200191146/US20200191146A1-20200618-D00003.png)
![](/patent/app/20200191146/US20200191146A1-20200618-D00004.png)
United States Patent
Application |
20200191146 |
Kind Code |
A1 |
RINALDI; Budi ; et
al. |
June 18, 2020 |
COMPRESSOR
Abstract
An electric-motor refrigerant compressor, for compressing a
fluid, having a compressor housing having a housing bottom, and
having a compressor part mounted in the compressor housing for
conveying the fluid from a low pressure-side inlet to a high
pressure-side outlet. The separating device is introduced into the
housing bottom and has a cylindrical separating chamber which is
connected to the outlet, and a separator which is arranged
coaxially in said separating chamber for separating lubricant which
is contained in the fluid, and a high pressure chamber of the
compressor housing is coupled in flow terms by means of a passage
duct to the separating chamber. The passage duct may be made in an
intermediate wall between the high pressure chamber and the
separating chamber in such a way that said passage duct opens into
the separating chamber offset radially and on the outer side of the
separator.
Inventors: |
RINALDI; Budi; (Frankfurt am
Main, DE) ; FAGERLI; Bjorn; (Rosbach vor der Hohe,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Brose Fahrzeugteile GmbH & Co. Kommanditgesellschaft,
Wurzburg |
Wurzburg |
|
DE |
|
|
Assignee: |
Brose Fahrzeugteile GmbH & Co.
Kommanditgesellschaft, Wurzburg
Wurzburg
DE
|
Family ID: |
62044746 |
Appl. No.: |
16/608564 |
Filed: |
April 24, 2018 |
PCT Filed: |
April 24, 2018 |
PCT NO: |
PCT/EP2018/060426 |
371 Date: |
October 25, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04C 29/026 20130101;
F04C 29/028 20130101; F04C 18/0215 20130101; F04B 39/121 20130101;
F04B 39/123 20130101; F04C 2240/30 20130101; F04C 2240/40 20130101;
F04B 35/04 20130101; F04C 18/0253 20130101; F04B 39/16
20130101 |
International
Class: |
F04C 18/02 20060101
F04C018/02; F04C 29/02 20060101 F04C029/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 27, 2017 |
DE |
10 2017 207 145.1 |
Claims
1. An electric-motor refrigerant compressor configured to compress
a fluid comprising: a housing having a housing bottom; a compressor
part mounted in the housing and configured to deliver the fluid
from a low-pressure-side inlet to a high-pressure-side outlet; and
a separating device inserted into the housing bottom, wherein the
separating device includes a cylindrical separating chamber
connected to the high-pressure-side outlet and a separator, wherein
the separator is arranged coaxially in the separating chamber and
configured to separate lubricant contained in the fluid from the
fluid, wherein a high-pressure chamber of the housing is coupled in
terms of flow to the separating chamber by a passage duct, wherein
the passage duct is formed by an intermediate wall disposed between
the high-pressure chamber and the separating chamber in such a way
that the passage duct opens into the separating chamber in a manner
offset radially with respect to a central center line of the
separator, and wherein a clear width of the passage duct is less
than or equal to a gap width of an annular gap formed between the
separator and an inner wall of the separating chamber.
2. The electric-motor refrigerant compressor of claim 1, wherein
the passage duct is positioned in such a way that the fluid flows
into the separating chamber and tangentially to the separator.
3. The electric-motor refrigerant compressor of claim 1, wherein
the passage duct is offset radially with respect to the central
center line of the separator by an offset, wherein a sum of the
offset and of the clear width of the passage duct is less than or
equal to a radius of the separating chamber.
4. The electric-motor refrigerant compressor of claim 1, wherein
the passage duct has an inner wall oriented parallel to an inflow
direction of the fluid and/or perpendicularly to the housing
bottom.
5. The electric-motor refrigerant compressor of claim 4, wherein
the separating chamber is oriented radially with respect to the
housing bottom, wherein the passage duct is elongated and extends
in a radial direction.
6. The electric-motor refrigerant compressor of claim 1, wherein
the passage duct is a slotted aperture in the intermediate
wall.
7. The electric-motor refrigerant compressor of claim 6, wherein
the slotted aperture has a substantially rectangular
cross-sectional shape.
8. The electric-motor refrigerant compressor of claim 1, wherein
the separating chamber is formed between an inner wall of the
housing bottom and the high-pressure chamber and wherein the
separating chamber projects at least partially into the
high-pressure chamber.
9. The electric-motor refrigerant compressor of claim 1, wherein
the housing bottom has an annular wall projecting axially beyond
the separating chamber to form the high-pressure chamber, and
wherein the passage duct is arranged within the annular wall so
that the passage duct is radially offset from the center line of
the separator towards the outlet.
10. The electric-motor refrigerant compressor of claim 9, wherein
the compressor part lies along the annular wall.
11. An electric refrigerant compressor comprising: a housing
including a housing bottom, an annular wall axially spaced apart
from the housing bottom, and an intermediate wall extending from
the annular wall, wherein the intermediate wall, the housing
bottom, and the annular wall form a separating chamber; a
compressor part disposed within the housing and configured to
deliver a fluid from a low-pressure-side inlet to a
high-pressure-side outlet, wherein the compressor part, the
intermediate wall, and the annular wall form a high-pressure
chamber; and a separator defining a center line and disposed in the
separating chamber, wherein the intermediate wall defines a passage
duct, and wherein the separator and passage duct are arranged
relative to one another so that the passage duct is oblique to and
radially spaced apart from the center line of the separator.
12. The electric refrigerant compressor of claim 11, wherein the
passage duct includes a first inner wall, formed by the
intermediate wall, and a second inner wall, formed by the annular
wall, wherein the first inner wall is spaced apart from the second
inner wall by a first distance, wherein an outer surface of the
separator is spaced apart from the second inner wall by a second
distance, wherein the first distance is less than or equal to the
second distance.
13. The electric refrigerant compressor of claim 12, wherein the
first inner wall is spaced apart from the center line of the
separator by a third distance and wherein a radius of the separator
chamber is a fourth distance, wherein a sum of the first distance
and the third distance is less than or equal to the fourth
distance.
14. The electric refrigerant compressor of claim 11, wherein the
separating chamber extends at least partially into the
high-pressure chamber.
15. An electric refrigerant compressor comprising: a housing
including a housing bottom, an annular wall axially spaced apart
from the housing bottom, and an intermediate wall extending from
the annular wall, wherein the intermediate wall, the housing
bottom, and the annular wall form a separating chamber; a
compressor part disposed within the housing and configured to
deliver a fluid from a low-pressure-side inlet to a
high-pressure-side outlet, wherein the compressor part, the
intermediate wall, and the annular wall form a high-pressure
chamber; and a separator defining a center line and disposed in the
separating chamber, wherein the intermediate wall defines a passage
duct, and wherein the passage duct includes a first inner wall,
formed by the intermediate wall, and a second inner wall, formed by
the annular wall, wherein the first inner wall has a first length
and the second inner wall has a second length, less than the first
length.
16. The electric refrigerant compressor of claim 15, wherein the
first inner wall is spaced apart from the second inner wall by a
first distance, wherein an outer surface of the separator is spaced
apart from the second inner wall by a second distance, wherein the
first distance is less than or equal to the second distance.
17. The electric refrigerant compressor of claim 16, wherein the
first inner wall is spaced apart from the center line of the
separator by a third distance and wherein a radius of the separator
chamber is a fourth distance, wherein a sum of the first distance
and the third distance is less than or equal to the fourth
distance.
18. The electric refrigerant compressor of claim 15, wherein the
separating chamber extends between an outlet, formed by the bottom
housing, and a lubricant reservoir, and wherein one end of the
lubricant reservoir has a conical shape.
19. The electric refrigerant compressor of claim 15, wherein the
passage duct is elongated and extends in a radial direction.
20. The electric refrigerant compressor of claim 19, wherein the
passage duct has a rectangular cross-sectional shape.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. National Phase of
PCT/EP2018/060426 filed Apr. 24, 2018, which claims priority to DE
10 2017 207 145.1 filed Apr. 27, 2017, the disclosures of which are
hereby incorporated in their entirety by reference herein.
TECHNICAL FIELD
[0002] The present disclosure relates to a compressor including an
electric motor for use in an air-conditioning unit of a motor
vehicle.
BACKGROUND
[0003] In vehicles, it is normal practice to install an
air-conditioning unit which can cool the vehicle interior in the
manner of a compression-type refrigeration unit. Fundamentally,
systems of this kind have a circuit which contains a refrigerant,
e.g. R-134a (1,1,1,2-tetrafluoroethane) or R-774 (CO.sub.2). During
operation, the refrigerant is compressed by a compressor, leading
to an increase in the pressure and temperature of the refrigerant.
In particular, the compressor is driven in by an electric
motor.
SUMMARY
[0004] Positioned downstream of the (refrigerant) compressor in
terms of flow is a condenser, which is in thermal contact with the
surroundings of the vehicle. As a consequence, the temperature of
the refrigerant is lowered in the condenser, and the refrigerant is
then passed into an evaporator positioned downstream in terms of
flow. In the evaporator, the refrigerant is expanded to the
original pressure, as a result of which the temperature of the
refrigerant falls further.
[0005] Positioned downstream of the evaporator in terms of flow is
a further heat exchanger, which is in thermal contact with a blower
line of the air-conditioning unit leading into the interior of the
vehicle. In this situation, thermal energy is transferred from the
thermally contacted component to the refrigerant, leading to
cooling of the component and heating of the refrigerant. To close
the circuit, the refrigerant is fed back to the compressor.
[0006] Arranged in series in the flow direction in the compressor
of the circuit and, in the compressor, in the compressor housing,
which has a housing bottom, there are a first low-pressure-side
compressor element of a compressor part and a second
high-pressure-side compressor element of the compressor part, the
latter being mounted in a fixed manner, for compressing the fluid,
as well as a high-pressure chamber and a separating device.
[0007] Within the compressor there is a lubricant, which mixes with
a gaseous refrigerant during operation. The lubricant (oil) serves
to reduce the friction which occurs during operation in the
compressor between the first compressor element and the second,
high-pressure-side compressor element, which is mounted in a fixed
manner. Furthermore, the lubricant performs a sealing function,
ensuring that any (refrigerant) leaks arising between the
compressor elements are reduced to a very great extent or
completely avoided, which increases the efficiency of the
refrigerant compressor.
[0008] As an example, the refrigerant mixed with lubricant, after
being compressed by the compressor part in the compressor, flows
into a high-pressure chamber which, in turn, is coupled to the
separating device by a passage duct. In the separating device, the
oil is separated from the refrigerant, and the separated oil is
thus or may thus be returned to the compressor via a valve and a
lubricant duct, and the refrigerant is passed into the refrigerant
circuit via an outlet of the separating device as far as possible
without oil.
[0009] The separating device has a separating chamber connected to
the outlet and, in the chamber, a coaxially arranged separator,
with the result that an annular space is formed between the
separator and an inner wall of the separating chamber. The passage
duct of the separating device is embodied as a round hole, wherein
the fluid flows from the high-pressure chamber into the annular
space of the separating chamber via the passage duct. In this
process, the fluid flows from the high-pressure chamber into the
separating chamber through a flow cross section matched to the
delivery volume which occurs during operation and is determined by
the clear width of the passage duct. Since the cross-sectional area
of the flow cross section must be matched to the delivery volume
which occurs during operation, the fluid flow branches into two
partial flows, which are guided in opposite directions of flow
along the two sides of the separator. This entails unwanted eddy
formation in the annular space between the separator and the
chamber inner wall of the separating chamber.
[0010] One or more objects of the present disclosure may be to
provide a compressor in which the fluid delivered flows through the
separating chamber with as little eddy formation as possible.
[0011] The device according to one or more embodiments, a
compressor for compressing a fluid, in particular a refrigerant,
wherein the compressor is arranged between a heat exchanger and a
condenser in terms of flow, in a refrigerant circuit of an
air-conditioning system. Here, the compressor has the task of
increasing the pressure of the fluid delivered. The compressor has
a (compressor) housing having a housing bottom and a compressor
part, mounted in the housing, for delivering the fluid from a
low-pressure-side inlet to a high-pressure-side outlet.
[0012] Within the compressor part and in a drive, such as an
electric-motor drive, of the compressor part there is a lubricant,
which mixes with the gaseous refrigerant during operation. It
serves to reduce friction in the compressor part and in the drive
thereof and performs a sealing function in the compressor part in
that it to a very great extent reduces or completely prevents leaks
between a first low-pressure-side compressor element and a second,
high-pressure-side compressor element, the latter being mounted in
a fixed manner. The lubricant should be separated from the fluid
before being passed into the refrigerant circuit. The oil separated
off and collected in a (lubricant) reservoir can advantageously be
returned to the compressor part via a valve and a lubricant
passage, leading to improved lubrication of the compressor elements
and reducing friction in the compressor part. A further advantage
conferred by the separation of the lubricant from the fluid is
improved heat transfer to the heat exchanger of the refrigerant
circuit, which increases the efficiency of the air-conditioning
unit (of the air-conditioning or air-conditioning unit system).
[0013] For this purpose, a separating device for separating off the
lubricant contained in the fluid is inserted into the housing
bottom, wherein the separating device has a cylindrical separating
chamber that is connected to the outlet and has a separator, which
is arranged coaxially in the separating chamber.
[0014] The fluid flows out of the compressor part into a
high-pressure chamber of the compressor housing, the chamber being
positioned downstream of the part in terms of flow. The
high-pressure chamber is coupled to the separating device in terms
of flow by a passage duct in a common intermediate wall of the
separating chamber and the high-pressure chamber. Here, the passage
duct is introduced in such a way that it opens in a manner offset
radially with respect to the central center line of the separator,
which is arranged coaxially in the separating chamber and is, in
particular, cylindrical, this ensuring selective guidance of the
flow along just one side of the separator.
[0015] In particular, the compressor is an electric-motor
refrigerant compressor for an air-conditioning unit of a vehicle.
In operation, the air-conditioning unit is used to cool an interior
of the vehicle or to cool an energy storage device for driving an
electric-motor-operated vehicle, for example.
[0016] The heat exchanger is in thermal contact with any energy
cells of a high voltage energy storage device or with a blower line
leading into the interior of the motor vehicle. In this case,
transfer of thermal energy to the refrigerant takes place, leading
to cooling of the component in contact with the heat exchanger and
to heating of the refrigerant. The condenser may be used to adjust
the temperature of the refrigerant to the ambient temperature or at
least to lower the temperature of the refrigerant and may be in
thermal contact with the surroundings.
[0017] The compressor part is appropriately embodied as a scroll
compressor. This operates as a refrigerant compressor in the manner
of a positive displacement pump, wherein an electric motor drives a
moving scroll part eccentrically relative to a fixed scroll part
and, in doing so, compresses a fluid. The scroll parts form the
compressor elements of the compressor part and, in this case, are
typically embodied as a nested pair of spirals or scrolls. In this
case, one of the spirals is fixed in relation to the compressor
housing and engages at least partially in a second spiral, which is
driven in an orbiting manner by an electric motor. In this context,
an orbiting movement should be taken to mean, in particular, an
eccentric circular orbit in which the second spiral itself does not
rotate about its own axis. Two substantially crescent-shaped
refrigerant chambers, the volume of which is reduced (compressed)
in the course of the movement, are thereby formed between the
spirals during each orbiting movement. The refrigerant is
discharged into the high-pressure chamber via an outlet in the
fixed scroll part.
[0018] The lubricant is expediently a (lubricating) oil, wherein
the term "oil" should not be interpreted restrictively as mineral
oils. On the contrary, it is also possible to use fully synthetic
or partially synthetic oils, e.g. silicone oils, or other oil-like
fluids such as hydraulic fluid or cooling lubricants.
[0019] The separating device separates the lubricant from the fluid
in the manner of a centrifugal separator (cyclone separator). The
fluid flowing tangentially into the separating chamber is guided
along the separator in a helical manner (in the manner of a
cyclone) in the separating chamber, which is, in particular,
cylindrical. During this process, centrifugal forces act as a
separating mechanism on the mixture of refrigerant and lubricant.
In one conceivable embodiment, the lubricant reservoir is partially
closed by a cone to form an annular slot in order to avoid the
take-up of particles of the already separated lubricant by the
fluid flow.
[0020] In an expedient embodiment, the compressor housing, together
with the housing bottom, and the separating chamber of the
separating device are formed by a diecasting method. Production
which is particularly economical with materials and inexpensive is
thereby ensured.
[0021] In an expedient embodiment, the passage duct is introduced
in such a way into the intermediate wall between the separating
chamber and the high-pressure chamber that the fluid delivered
flows into the separating chamber tangentially to the separator,
thereby ensuring particularly suitable positioning of the passage
duct. In this case, the fluid flows in at an angle of less than
90.degree. to the housing bottom, for example. It is also possible
for the passage duct to be introduced into the intermediate wall in
such a way that the inflow direction of the fluid is perpendicular
to the housing bottom, as a result of which the flow direction of
the fluid through the passage duct is substantially identical with
the delivery direction of the fluid by the compressor part, and
less eddying arises at the passage duct. In this context, the
inflow direction should be taken to mean the direction tangential
to the separator in which the fluid flows into the separating
chamber.
[0022] The invention proceeds from the consideration that the
unwanted eddy formation in the annular space between the separator
and the chamber inner wall of the separating chamber can be reduced
considerably if the flow of the fluid is guided selectively along
only one side of the separator. For this purpose, the passage duct
opening into the annular space should be positioned as far as
possible in a manner offset fully azimuthally with respect to the
diameter of the separator.
[0023] In one or more embodiments, the clear width of the passage
duct exceeds the gap width of an annular gap formed between the
separator and an inner wall of the separating chamber. In other
words, the clear width of the passage duct is less than or equal to
the gap width of the annular gap. As a result, the fluid flows
particularly advantageously tangentially into the annular gap and
is guided selectively along just one side of the separator, thereby
considerably reducing eddy formation.
[0024] In a suitable embodiment, the passage duct has an inner
wall, which is oriented tangentially to the inflow direction of the
fluid into the annular gap. In other words, the inner wall of the
passage duct is oriented parallel to the inflow direction of the
fluid into the separating chamber, as an advantageous result of
which less eddying occurs at the passage duct during inflow.
[0025] As one example, the cylindrical separating chamber extends
radially with respect to the housing bottom of the compressor
housing, which is appropriately of pot-type shape. Here, the
passage duct is of elongate shape along this radial direction. The
flow cross section, formed by the clear width of the passage duct,
during the inflow of the fluid from the high-pressure chamber into
the separating chamber is matched to the fluid delivery volume
which occurs during operation.
[0026] Since the flow cross section, formed by the clear area of
the passage duct, from the high-pressure chamber into the
separating chamber should be matched to the delivery volume which
occurs during operation, and the clear width of the passage duct
may be less than or equal to the gap width of the gap formed
between the separator and the inner wall of the separating chamber,
the passage duct is consequently of elongate design along the
central center line of the separating device.
[0027] To avoid unwanted eddy formation, the passage duct is offset
radially with respect to the center line of the separating device
or with respect to the center line of the separator. In this case,
the offset, including the clear width of the passage duct, is
advantageously less than or equal to the radius of the cylindrical
separating chamber. As a result, the fluid flows tangentially into
the gap formed between the separator and the inner wall of the
separating chamber. As a consequence, the fluid is guided
selectively on only one side of the separator along an eddy-free
path. Branching off of a partial flow of the fluid, which would be
guided along the separator in the opposite direction of circulation
from the eddy-free path, would collide with the eddy-free path and
would lead to the formation of eddies, is avoided.
[0028] It is particularly advantageous if the passage duct is a
slotted aperture in the intermediate wall. In an expedient
embodiment, the shape of the passage duct has a substantially
rectangular cross-sectional shape. In one conceivable embodiment,
the cross-sectional shape of the passage duct is elliptical or
oval. Here, the shape of the passage duct is matched to the
operational delivery rate in such a way that the clear width of the
passage duct changes only along the axis of the separating chamber.
In other words, the passage duct between the separating chamber and
the high-pressure chamber is matched in such a way to the
operationally required delivery volume of the refrigerant that the
fluid delivered flows through the separating chamber with only
slight eddy formation.
[0029] In an expedient development, the separating chamber is
formed between an inner wall of the housing bottom, the wall facing
the compressor part, and the high-pressure chamber, wherein the
separating chamber projects at least partially axially into the
high-pressure chamber. A particularly space-saving and
material-saving embodiment is thereby formed.
[0030] In another embodiment, the housing bottom has an annular
wall which projects axially beyond the separating chamber, forming
an inner and an outer annular region. The passage duct from the
high-pressure chamber into the separating chamber is arranged
radially offset in the direction of the outlet in the inner annular
region, with the result that the fluid flow is guided around the
separator of the separating chamber in a particularly advantageous
manner along a cyclone-type path. In particular, this ensures
improved separation of the lubricant from the refrigerant.
[0031] Furthermore, it is appropriate if the compressor part rests
on the annular wall. In this case, the high-pressure chamber is
formed by the housing bottom, the annular wall and the compressor
part. In particular, additional sealing elements of the
high-pressure chamber are not required, which saves space and is
particularly advantageous in terms of flow.
[0032] One or more advantages may be obtained by the present
disclosure may be that the eddy formation of the fluid flow in the
separating chamber is considerably reduced by virtue of the
particularly suitable arrangement and embodiment of the passage
duct, taking account of the required delivery volume. For example,
the cross-sectional shape of the passage duct is here adapted in
such a way that, for the purpose of advantageous inflow behavior,
the clear width of the passage duct does not exceed the gap width
of the annular space (annular gap) formed between the separating
chamber and the separator and is advantageously of elongate design
along the axis of the separating chamber.
[0033] As a consequence of the reduced eddy formation, the
lubricant separates better from the refrigerant and is not carried
into the refrigerant circuit, for which reason there is better heat
transfer between the heat exchangers and the refrigerant in the
refrigerant circuit. Furthermore, owing to the improved separation,
the lubrication of the compressor part by the separated and
returned lubricant is improved, resulting in reduced wear and thus
a longer life of the compressor. Moreover, the efficiency of the
compressor is improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] An illustrative embodiment of the invention is explained in
greater detail below with reference to a drawing. In the
drawing:
[0035] FIG. 1 shows a longitudinal section through a compressor
having a housing and a compressor part and of a separating device
on the housing bottom side,
[0036] FIG. 2 shows the compressor housing in a plan view, viewed
in the direction of the bottom-side separating device, with a
passage duct of slotted cross-sectional shape,
[0037] FIG. 3 shows the separating device and the flow path of a
fluid through the passage duct and in the separating device in a
sectional illustration along the line in FIG. 2, and
[0038] FIG. 4 shows the sectional illustration from FIG. 3 with a
passage duct offset with respect to the center line of the
separating device and without the flow path of the fluid in the
separating device.
[0039] In all the figures, corresponding parts are in all cases
provided with the same reference signs.
DETAILED DESCRIPTION
[0040] As required, detailed embodiments of the present invention
are disclosed herein; however, it is to be understood that the
disclosed embodiments are merely exemplary of the invention that
may be embodied in various and alternative forms. The figures are
not necessarily to scale; some features may be exaggerated or
minimized to show details of particular components. Therefore,
specific structural and functional details disclosed herein are not
to be interpreted as limiting, but merely as a representative basis
for teaching one skilled in the art to variously employ the present
invention.
[0041] The compressor 2 illustrated in a sectional illustration in
FIG. 1 for compressing a fluid F may be embodied as an
electric-motor refrigerant compressor in a refrigerant circuit (not
illustrated specifically) of an air-conditioning unit of a motor
vehicle. The compressor 2 has a compressor housing 4 having a
housing bottom 6 and a compressor part 8 mounted in the housing 4.
The compressor part 8 has a first compressor element 8a, which is
fixed relative to the compressor housing 4, and a moving second
compressor element 8b, which engages therein and which is moved by
shaft journals 10 and a motor shaft 12 by an electric motor (not
illustrated specifically). Here, the compressor part 8 is embodied
as a scroll compressor.
[0042] Within the compressor 2 there is a lubricant S, which is
used to lubricate the compressor part 8 and performs a sealing
function, thus avoiding leaks between the compressor elements 8a
and 8b. Due to operating conditions, a refrigerant K and the
lubricant S mix with the fluid F in this case.
[0043] The compressor housing 4 is embodied in the manner of a pot.
The radial direction in relation to the compressor housing 4 and
the axial direction perpendicular to the housing bottom 6 in the
direction of the compressor part 8 are denoted in the adjacent
direction diagram by R and A, respectively.
[0044] A separating device 14, which is connected to an outlet 16,
is inserted into the housing bottom 6. The separating device 14 has
a cylindrical separating chamber 18 and a hollow-cylindrical
separator 20 arranged coaxially therein. The separating device 14
serves to separate the lubricant S contained in the fluid F into a
lubricant reservoir 26 in the manner of a centrifugal separator. In
the separating chamber 18, the fluid F flowing into the separating
chamber 18 in an inflow direction E (FIG. 3) via a passage duct 27
flows around the separator 20 helically (in the manner of a
cyclone) in the direction of the lubricant reservoir 26, wherein
the centrifugal force acting on the refrigerant K contained in the
fluid F and on the lubricant S contained in the fluid F acts as a
separating mechanism. The refrigerant K separated from the
lubricant S then flows out through the hollow-cylindrical separator
20 and the outlet 16 into the refrigerant circuit. In this context,
the inflow direction E should be taken to mean the direction
tangential to the separator 20 in which the fluid F flows into the
separating chamber 18.
[0045] The separated lubricant S is fed back to the fixed
compressor element 8b via a valve or restrictor 28 and via a
lubricant duct 30. In this arrangement, the restrictor 26 is seated
in the compressor housing 4. The returned lubricant S then flows
via guide contours to rolling bearings 32 of the electric motor
(not illustrated specifically) in order to lubricate and/or cool
the bearings.
[0046] The axial direction of the separating device 14, i.e. the
axial direction of the cylindrical separating chamber 18 and of the
separator arranged coaxially therein, is denoted by X. The radial
direction of the separating device 14 perpendicular to the inflow
direction E and the radial direction of the separating device 14
parallel to the inflow direction E are denoted by Y and Z,
respectively (FIG. 2).
[0047] Furthermore, the housing bottom 6 has an annular wall 34
projecting beyond the separating chamber 18. This divides the space
surrounded by the fixed compressor part 8b and by the compressor
housing 4 into an inner annular region 36 and into an outer annular
region 38. A high-pressure chamber 40 is formed by the inner
annular region 36, bounded by the housing bottom 6, the annular
wall 34 and the compressor element 8b resting on the annular wall
34.
[0048] The separating chamber 18 is formed between an inner wall 41
of the housing bottom 6 and the high-pressure chamber 40, wherein
the separating chamber 18 projects at least partially into the
high-pressure chamber 40 in the axial direction A. The passage duct
27 couples the high-pressure chamber 40 to the separating chamber
18 in terms of flow. The passage duct 27 is introduced into an
intermediate wall 44 between the separating chamber 18 and the
high-pressure chamber 40 in such a way that the passage duct 27
opens into the separating chamber 18 in a manner offset along the
radial direction Y of the separating device 14 with respect to the
axial direction X of the separating device 14. In this case, the
passage duct 27 is arranged in such a way in the inner annular
region 36 of the annular wall 34 that the passage duct 27 is offset
in the axial direction X of the separating device 14 or in the
radial direction R of the compressor housing 4 toward the
outlet.
[0049] On the low-pressure side of the compressor part 8, the fluid
F flows into the compressor part 8 through an inlet 46. The
compressor part 8, which in this case is a scroll compressor,
compresses the fluid F in the manner of a positive displacement
pump. The fluid F is compressed in a compressor part chamber 47 and
then flows out of the compressor part 8 into the high-pressure
chamber 40 through a high-pressure-side compressor part outlet
48.
[0050] FIG. 2 shows the pot-type compressor housing 4 with the
compressor part 8 removed, looking at the housing bottom 6 of the
compressor housing 4 along the axial direction A. The annular wall
34 projects beyond the separating device 14, forming the inner
annular region 36 and the outer annular region 38. With the
compressor part 8 (not illustrated in FIG. 2) and the housing
bottom 6 of the compressor housing 4, the annular wall 34 forms the
high-pressure chamber 40.
[0051] Furthermore, the compressor housing 4 has screw sockets 50
along a flange surface 49 to enable the compressor 2 to be fastened
to a drive module (not illustrated), into which the motor of the
compressor 2 is inserted. For the sake of greater clarity, only two
screw sockets 50 are provided with a reference sign in FIG. 2.
[0052] The separating chamber 18 extends in the radial direction R
with respect to the housing bottom 6 of the compressor housing 4.
In this case, the passage duct 27 is offset in the radial direction
R toward the outlet 16 of the separating chamber 18 in the inner
annular region 36 and is of elongate shape along the axial
direction X of the separating device 14. The passage duct 27 is
embodied as a slotted aperture in the intermediate wall 44, wherein
the aperture has a substantially rectangular cross-sectional shape.
The cross-sectional shape of the passage duct 27 can be of slotted
or oval design.
[0053] FIG. 3 shows the separating device 14 inserted into the
housing bottom 6 of the compressor housing 4, looking toward the
radially offset passage duct 27, in a sectional illustration along
the line in FIG. 2. As is apparent, this passage is positioned in
the intermediate wall 44 between the high-pressure chamber 40 and
the separating chamber 18 in such a way that the fluid F delivered
flows into the separating chamber 18 tangentially to the separator
20 in the inflow direction E.
[0054] In this case, the passage duct 27 has an inner wall 55,
which is oriented tangentially to the inflow direction E of the
fluid F in the passage duct 27. In this illustrative embodiment,
the fluid F flows into the separating chamber 18 in such a way that
both the inflow direction E and the inner wall 55 of the passage
duct 27 are oriented perpendicularly to the housing bottom 6. That
side of the inner wall 55 of the passage duct 27, the distance c
(FIG. 4) of which from the radial direction or line Z, illustrated
in dashed lines, of the separating device 14 parallel to the inflow
direction E or, in this illustrative embodiment, perpendicular to
the housing bottom 6 is shorter, is denoted by 55a (side closer to
the axis). The opposite side of the inner wall 55 of the passage
duct 27 is denoted by 55b (side remote from the axis).
[0055] The flow cross section, formed by the clear area of the
passage duct 27, during the inflow of the fluid F from the
high-pressure chamber 40 into the separating chamber 18 is matched
to the operationally required fluid delivery volume. To avoid eddy
formation of the flow of the fluid F in the separating chamber 18,
the passage duct 27 is here matched to the operationally required
delivery volume in such a way that the clear width a of the passage
duct 27 may be smaller than the gap width b (a<b) of an annular
gap 58 formed between the separator 20 and an inner wall 56 of the
separating chamber 18. However, the clear width a can also be equal
to the gap width b (a=b). Moreover, the passage duct 27 is of
elongate shape along the axial direction X of the separating device
14. As a result, the fluid F flows tangentially into the annular
gap 58 and is guided exclusively along one side of the separator
20, along an eddy-free path 60. Branching off of a second partial
flow of the fluid F, indicated by the dashed arrows in FIG. 3,
which would be guided along the separator 20 in the opposite
direction of circulation from the eddy-free path 60 and would
collide with the eddy-free path 60, is thereby avoided.
[0056] FIG. 4 shows, in the sectional illustration of FIG. 3, the
separating device 14 inserted into the housing bottom 6, with the
passage duct 27 having the clear width a and the gap formed by the
inner wall 56 of the separating chamber 18 and the separator 20,
having the gap width b.
[0057] To avoid unwanted eddy formation, the fluid F flows
tangentially into the annular gap 58 formed between the separator
20 and the inner wall 56 of the separating chamber 18. As a
consequence, the fluid F is guided selectively on only one side of
the separator 20 along an eddy-free path 60 (FIG. 3). For this
purpose, the passage duct 27 is in this illustrative embodiment
offset along the radial direction Y of the separating device 14
relative to the center line X of the separating device 14 or
relative to the center line X of the separator 20, wherein the
offset c together with the clear width a of the passage duct 27 is
less than or equal to the radius d of the separating chamber 18 or
the inner wall 56 thereof, i.e. c+a.ltoreq.d. In other words, the
offset c is the distance between the radial direction Z of the
separating device 14 parallel to the inflow direction E and that
side 55a of the inner wall 55 of the passage duct 27 which faces
the central center line X.
[0058] The invention is not restricted to the illustrative
embodiments described above. On the contrary, other variants of the
invention can be derived therefrom by a person skilled in the art
without exceeding the subject matter of the invention. In
particular, all the individual features described in conjunction
with the illustrative embodiments can furthermore also be combined
in different ways without departing from the subject matter of the
invention.
[0059] While exemplary embodiments are described above, it is not
intended that these embodiments describe all possible forms of the
invention. Rather, the words used in the specification are words of
description rather than limitation, and it is understood that
various changes may be made without departing from the spirit and
scope of the invention. Additionally, the features of various
implementing embodiments may be combined to form further
embodiments of the invention.
LIST OF REFERENCE SIGNS
[0060] 2 compressor [0061] 4 compressor housing [0062] 6 housing
bottom [0063] 8 compressor part [0064] 8a first compressor element
[0065] 8b second compressor element [0066] 10 shaft journal [0067]
12 motor shaft [0068] 14 separating device [0069] 16 outlet [0070]
18 separating chamber [0071] 20 separator [0072] 26 lubricant
reservoir [0073] 27 passage duct [0074] 28 restrictor [0075] 30
lubricant duct [0076] 32 rolling bearing [0077] 34 annular wall
[0078] 36 inner annular region [0079] 38 outer annular region
[0080] 40 high-pressure chamber [0081] 41 inner wall of the housing
bottom [0082] 44 intermediate wall [0083] 46 inlet [0084] 47
compressor part chamber [0085] 48 compressor part outlet [0086] 49
flange surface [0087] 50 screw sockets [0088] 55 inner wall of the
passage duct [0089] 55a side of the inner wall closer to the axis
[0090] 55b side of the inner wall remote from the axis [0091] 56
inner wall of the separating chamber [0092] 58 annular gap [0093]
60 flow path of the fluid [0094] A axial direction of the
compressor housing [0095] E inflow direction [0096] F fluid [0097]
K refrigerant [0098] S lubricant [0099] M center line of the
separator [0100] R radial direction of the compressor housing
[0101] X axial direction/center line of the separating device
[0102] Y radial direction of the separating device perpendicular to
the inflow direction [0103] Z radial direction of the separating
device parallel to the inflow direction [0104] a clear width [0105]
b gap width [0106] c distance/offset [0107] d radius of the inner
wall of the separating chamber
* * * * *