U.S. patent application number 13/975808 was filed with the patent office on 2014-04-24 for turbocharger.
This patent application is currently assigned to OTICS Corporation. The applicant listed for this patent is OTICS Corporation. Invention is credited to Tomoyuki ISOGAI.
Application Number | 20140112762 13/975808 |
Document ID | / |
Family ID | 49263107 |
Filed Date | 2014-04-24 |
United States Patent
Application |
20140112762 |
Kind Code |
A1 |
ISOGAI; Tomoyuki |
April 24, 2014 |
TURBOCHARGER
Abstract
The present invention provides a turbocharger including a
compressor housing provided therein with an air flow path in which
an impeller is disposed and a bearing housing. The air flow path
includes a suction port and a discharge scroll chamber. The
compressor housing includes a shroud surface and a diffuser
surface. The bearing housing includes a facing surface which is
facing to the diffuser surface. A cleaning agent supplying units
are provided in the diffuser surface and the facing surface. The
cleaning agent supplying units include porous supplying portions
for forming at least a portion of the diffuser surface or the
facing surface, and a cleaning agent for preventing adhesion of
deposits is supplied from the porous supplying portions to the
diffuser surface or the facing surface.
Inventors: |
ISOGAI; Tomoyuki; (Aichi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
OTICS Corporation |
Nishio-city |
|
JP |
|
|
Assignee: |
OTICS Corporation
Nishio-city
JP
|
Family ID: |
49263107 |
Appl. No.: |
13/975808 |
Filed: |
August 26, 2013 |
Current U.S.
Class: |
415/121.3 |
Current CPC
Class: |
F04D 29/441 20130101;
F04D 29/705 20130101; F05D 2220/40 20130101; F01D 25/002 20130101;
F02B 39/16 20130101 |
Class at
Publication: |
415/121.3 |
International
Class: |
F01D 25/00 20060101
F01D025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 22, 2012 |
JP |
2012-232818 |
Claims
1. A turbocharger comprising: a compressor housing provided therein
with an air flow path in which an impeller is disposed; and a
bearing housing for rotatably supporting a rotor shaft to which the
impeller is connected, wherein: the air flow path includes a
suction port through which air is sucked toward the impeller, and a
discharge scroll chamber which is formed on an outer peripheral
side of the impeller in its circumferential direction, and which
guides, to outside, compressed air discharged from the impeller;
the compressor housing includes a shroud surface facing to the
impeller, and a diffuser surface extending from the shroud surface
toward the discharge scroll chamber; the bearing housing includes a
facing surface which is facing to the diffuser surface of the
compressor housing and which forms a diffuser passage between the
facing surface and the diffuser surface; a cleaning agent supplying
unit is provided in at least one of the diffuser surface of the
compressor housing and the facing surface of the bearing housing;
and the cleaning agent supplying unit includes a porous supplying
portion made of porous material for forming at least a portion of
the diffuser surface or the facing surface, and is configured such
that cleaning agent for preventing adhesion of deposits is supplied
from the porous supplying portion to the diffuser surface or the
facing surface.
2. The turbocharger according to claim 1, wherein the bearing
housing includes a bearing body and a back plate which is disposed
between the bearing body and the compressor housing and which faces
to a portion of the air flow path, the bearing body and the back
plate are separated from each other, and the back plate is provided
with the facing surface.
3. The turbocharger according to claim 1, wherein the cleaning
agent supplying unit is configured such that the cleaning agent
passes through the porous supplying portion and is supplied to the
diffuser surface or the facing surface.
4. The turbocharger according to claim 2, wherein the cleaning
agent supplying unit is configured such that the cleaning agent
passes through the porous supplying portion and is supplied to the
diffuser surface or the facing surface.
5. The turbocharger according to claim 3, wherein the porous
supplying portion is configured such that the cleaning agent in a
liquid state does not pass through the porous supplying portion and
the cleaning agent in a gas state passes through the porous
supplying portion, and the cleaning agent supplying unit is
configured such that the cleaning agent in the liquid state is
vaporized under a predetermined condition, the cleaning agent
passes through the porous supplying portion and is supplied to the
diffuser surface or the facing surface.
6. The turbocharger according to claim 4, wherein the porous
supplying portion is configured such that the cleaning agent in a
liquid state does not pass through the porous supplying portion and
the cleaning agent in a gas state passes through the porous
supplying portion, and the cleaning agent supplying unit is
configured such that the cleaning agent in the liquid state is
vaporized under a predetermined condition, the cleaning agent
passes through the porous supplying portion and is supplied to the
diffuser surface or the facing surface.
7. The turbocharger according to claim 1, wherein the cleaning
agent supplying unit is configured such that the porous supplying
portion is impregnated with the cleaning agent in a liquid state,
the cleaning agent is vaporized under a predetermined condition and
is supplied to the diffuser surface or the facing surface.
8. The turbocharger according to claim 2, wherein the cleaning
agent supplying unit is configured such that the porous supplying
portion is impregnated with the cleaning agent in a liquid state,
the cleaning agent is vaporized under a predetermined condition and
is supplied to the diffuser surface or the facing surface.
9. The turbocharger according to claim 1, wherein the cleaning
agent supplying unit further includes a reservoir in which the
cleaning agent is stored, and the cleaning agent supplying unit
supplies the cleaning agent stored in the reservoir to the porous
supplying portion.
10. The turbocharger according to claim 2, wherein the cleaning
agent supplying unit further includes a reservoir in which the
cleaning agent is stored, and the cleaning agent supplying unit
supplies the cleaning agent stored in the reservoir to the porous
supplying portion.
11. The turbocharger according to claim 3, wherein the cleaning
agent supplying unit further includes a reservoir in which the
cleaning agent is stored, and the cleaning agent supplying unit
supplies the cleaning agent stored in the reservoir to the porous
supplying portion.
12. The turbocharger according to claim 4, wherein the cleaning
agent supplying unit further includes a reservoir in which the
cleaning agent is stored, and the cleaning agent supplying unit
supplies the cleaning agent stored in the reservoir to the porous
supplying portion.
13. The turbocharger according to claim 5, wherein the cleaning
agent supplying unit further includes a reservoir in which the
cleaning agent is stored, and the cleaning agent supplying unit
supplies the cleaning agent stored in the reservoir to the porous
supplying portion.
14. The turbocharger according to claim 6, wherein the cleaning
agent supplying unit further includes a reservoir in which the
cleaning agent is stored, and the cleaning agent supplying unit
supplies the cleaning agent stored in the reservoir to the porous
supplying portion.
15. The turbocharger according to claim 7, wherein the cleaning
agent supplying unit further includes a reservoir in which the
cleaning agent is stored, and the cleaning agent supplying unit
supplies the cleaning agent stored in the reservoir to the porous
supplying portion.
16. The turbocharger according to claim 8, wherein the cleaning
agent supplying unit further includes a reservoir in which the
cleaning agent is stored, and the cleaning agent supplying unit
supplies the cleaning agent stored in the reservoir to the porous
supplying portion.
Description
CROSS-REFERENCE
[0001] This application claims priority to Japanese patent
application no. 2012-232818 filed on Oct. 22, 2012, the contents of
which are entirely incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a turbocharger including a
compressor housing and a bearing housing.
[0004] 2. Description of the Related Art
[0005] A turbocharger provided in a car and the like is configured
such that air sucked in a compressor is compressed and discharged
toward an internal combustion engine (see Patent Document 1).
[0006] That is, the turbocharger includes a compressor housing
provided at its inner side with an air flow path. An impeller is
disposed in the air flow path. The turbocharger also includes a
bearing housing which rotatably supports a rotor shaft. The
impeller is connected to the rotor shaft. The air flow path
includes a suction port through which air is sucked toward the
impeller, and a discharge scroll chamber into which compressor air
discharged from the impeller flows.
[0007] The compressor housing includes a shroud surface which is
facing to the impeller, and a diffuser surface extending from the
shroud surface toward the discharge scroll chamber. The bearing
housing forms a diffuser passage between the bearing housing and
the diffuser surface of the compressor housing.
[0008] The turbocharger is configured such that the compressed air
discharged from the impeller passes through the diffuser passage
and flows into the discharge scroll chamber, and the compressed air
is discharged from the discharge scroll chamber toward the internal
combustion engine.
PATENT DOCUMENT
[0009] Patent Document 1: JP 2002-180841 A
SUMMARY OF THE INVENTION
[0010] For example, some internal combustion engines include a
positive crankcase ventilation system (PCV, hereinafter) which
refluxes, into a suction passage, blow-by gas (mainly unburned gas)
generated in a crankcase, and reheats the blow-by gas in a
combustion chamber. In this case, oil (oil mist) included in the
blow-by gas flows out, in some cases, from the PCV into the suction
passage on an upstream side of a compressor in a turbocharger.
[0011] At this time, if an outlet air pressure of the compressor is
high, an outlet air temperature also becomes high. Hence, oil which
flows out from the PCV is condensed and viscosity of the oil is
increased due to vaporization of the oil, the oil becomes deposits,
and the deposits accumulate, in some cases, on a diffuser surface
of a compressor housing, a surface of a bearing housing facing to
the diffuser surface, and the like. The diffuser passage is
narrowed by the accumulated deposits, and there may be a risk that
performance of the turbocharger is deteriorated and output of the
internal combustion engine is lowered.
[0012] Hence, to prevent the accumulation of deposits in the
diffuser passage, the outlet air temperature of the compressor is
conventionally lowered to some extent. Hence, the performance of
the turbocharger can not sufficiently be exerted, and the output of
the internal combustion engine can not sufficiently be
increased.
[0013] The present invention has been accomplished in view of the
background, and the invention provides a turbocharger capable of
preventing the accumulation of deposits in the diffuser
passage.
[0014] One aspect of the invention resides in a turbocharger
including
[0015] a compressor housing provided therein with an air flow path
in which an impeller is disposed; and
[0016] a bearing housing for rotatably supporting a rotor shaft to
which the impeller is connected, wherein:
[0017] the air flow path includes a suction port through which air
is sucked toward the impeller, and a discharge scroll chamber which
is formed on an outer peripheral side of the impeller in its
circumferential direction, and which guides, to outside, compressed
air discharged from the impeller;
[0018] the compressor housing includes a shroud surface facing to
the impeller, and a diffuser surface extending from the shroud
surface toward the discharge scroll chamber;
[0019] the bearing housing includes a facing surface which is
facing to the diffuser surface of the compressor housing and which
forms a diffuser passage between the facing surface and the
diffuser surface;
[0020] a cleaning agent supplying unit is provided in at least one
of the diffuser surface of the compressor housing and the facing
surface of the bearing housing; and
[0021] the cleaning agent supplying unit includes a porous
supplying portion made of porous material for forming at least a
portion of the diffuser surface or the facing surface, and is
configured such that cleaning agent for preventing adhesion of
deposits is supplied from the porous supplying portion to the
diffuser surface or the facing surface.
[0022] In the turbocharger, at least one of the diffuser surface of
the compressor housing and the facing surface of the bearing
housing is provided with the cleaning agent supplying unit having
the porous supplying portion. The porous supplying portion is
disposed such that it forms at least a portion of the diffuser
surface or the facing surface. The cleaning agent supplying unit is
configured such that the cleaning agent for preventing the adhesion
of deposits is supplied from the porous supplying portion to the
diffuser surface or the facing surface.
[0023] Hence, the cleaning agent supplied from the porous supplying
portion of the cleaning agent supplying unit to the diffuser
surface or the facing surface can prevent deposits from adhering to
the diffuser surface of the compressor housing or the facing
surface of the bearing housing. According to this, it is possible
to prevent deposits from adhering to (accumulating on) the diffuser
surface or the facing surface, i.e., it is possible to prevent the
adhesion (accumulation) of deposits in the diffuser passage formed
between the diffuser surface and the facing surface.
[0024] The porous supplying portion of the cleaning agent supplying
unit is formed from porous material, and the porous supplying
portion forms at least a portion of the diffuser surface and the
facing surface. Hence, it is possible to easily and directly supply
cleaning agent from pores formed in the porous supplying portion to
the diffuser surface and the facing surface by making cleaning
agent pass through the porous supplying portion, for example.
Hence, it is possible to efficiently prevent the adhesion of
deposits which will accumulate on the diffuser surface and the
facing surface.
[0025] As described above, it is possible to provide a turbocharger
capable of preventing the adhesion of deposits in the diffuser
passage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is an explanatory sectional view showing a
turbocharger in a first embodiment.
[0027] FIG. 2 is an explanatory enlarged sectional view showing a
cleaning agent supplying unit in the first embodiment.
[0028] FIG. 3 is an explanatory enlarged sectional view showing a
cleaning agent supplying unit in a second embodiment.
[0029] FIG. 4 is an explanatory sectional view showing a
turbocharger in a third embodiment.
[0030] FIG. 5 is an explanatory enlarged sectional view showing a
cleaning agent supplying unit in the third embodiment.
MODE FOR CARRYING OUT THE INVENTION
[0031] In the turbocharger, the cleaning agent supplying unit is
provided on at least one of the diffuser surface of the compressor
housing and the facing surface of the bearing housing. That is, the
cleaning agent supplying unit may be provided on one of or both of
the diffuser surface and the facing surface. It is preferable that
the cleaning agent supplying units are provided on both of them. In
this case, the effect for preventing the adhesion of deposits in a
diffuser passage can more sufficiently be obtained.
[0032] It is preferable that the porous supplying portion of the
cleaning agent supplying unit is annularly provided on the diffuser
surface of the compressor housing or the facing surface of the
bearing housing over the entire circumferential direction thereof.
In this case, the effect for preventing the adhesion of deposits in
the diffuser passage can more sufficiently be obtained.
[0033] It is preferable that the porous supplying portion of the
cleaning agent supplying unit is provided on the diffuser surface
of the compressor housing or the facing surface of the bearing
housing at a position closer to the impeller. In this case, the
effect for preventing the adhesion of deposits in the diffuser
passage can more sufficiently be obtained.
[0034] As porous material (including thin film and the like)
configuring the porous supplying portion of the cleaning agent
supplying unit, it is possible to use porous resin, metal, ceramic,
glass fiber, carbon graphite, and articles which are in proportion
to these examples (e.g., article obtained by rolling up resin film,
article obtained by superposing resin paper sheets on one another,
and article obtained by knitting resin string).
[0035] As the cleaning agent, it is possible to use a lubricant
such as KURE CRC5-56 produced by KURE Engineering Ltd., and
SUPER-CHECK CLEANING AGENT produced by MARKTEC Corporation.
[0036] The bearing housing includes a bearing body and a back plate
which is disposed between the bearing body and the compressor
housing and which faces to a portion of the air flow path, the
bearing body and the back plate are separated from each other, and
the back plate may be provided with the facing surface.
[0037] In the case of this configuration also, the effect for
preventing the adhesion of deposits in the diffuser passage can
sufficiently be obtained.
[0038] In the case of this configuration, it is also possible to
provide the back plate which is a portion of the bearing housing
with the cleaning agent supplying unit.
[0039] The cleaning agent supplying unit may be configured such
that the cleaning agent passes through the porous supplying portion
and is supplied to the diffuser surface or the facing surface.
[0040] In this case, it is possible to easily and directly supply
the cleaning agent from the porous supplying portion to the
diffuser surface or the facing surface. Further, it is possible to
control the supply of the cleaning agent to the diffuser surface or
the facing surface as will be described later.
[0041] The porous supplying portion may be configured such that the
cleaning agent in a liquid state does not pass through the porous
supplying portion and the cleaning agent in a gas state passes
through the porous supplying portion, and the cleaning agent
supplying unit may be configured such that the cleaning agent in
the liquid state is vaporized under a predetermined condition, the
cleaning agent passes through the porous supplying portion and is
supplied to the diffuser surface or the facing surface.
[0042] In this case, it is possible to control the supply of the
cleaning agent to the diffuser surface or the facing surface in
accordance with a condition such as an atmosphere temperature of
the compressor in the turbocharger.
[0043] Specifically, the turbocharger is configured such that a
temperature of compressed air becomes high (e.g., temperature of
165.degree. C. or higher) in the diffuser passage, and vaporized
cleaning agent of a necessary amount is supplied at a temperature
slightly lower than a temperature at which oil from a PCV becomes
deposits and the deposits adhere (lower than the above temperature
by 5 to 10.degree. C.). According to this, when it is necessary to
prevent deposits from adhering, vaporized cleaning agent of the
necessary amount passes through the porous supplying portion and is
supplied to the diffuser surface or the facing surface, and it is
possible to efficiently prevent deposits from adhering. In this
case, it is necessary to adjust a size (diameter) of each of the
pores in the porous supplying portion depending upon a size of
molecule of the cleaning agent, a boiling point of the cleaning
agent, and a supply amount of the cleaning agent.
[0044] The cleaning agent supplying unit may be configured such
that the porous supplying portion is impregnated with the cleaning
agent in a liquid state, the cleaning agent is vaporized under a
predetermined condition and is supplied to the diffuser surface or
the facing surface.
[0045] In this case, it is possible to easily and directly supply
the cleaning agent from the porous supplying portion to the
diffuser surface or the facing surface. Further, it is possible to
control the supply of the cleaning agent to the diffuser surface or
the facing surface in accordance with a condition such as an
atmosphere temperature of the compressor.
[0046] Specifically, as described above, the turbocharger is
configured such that vaporized cleaning agent of a necessary amount
is supplied at a predetermined temperature. According to this, when
it is necessary to prevent deposits from adhering, the cleaning
agent of a liquid state held in the pores in the porous supplying
portion is vaporized, the cleaning agent of a necessary amount is
supplied to the diffuser surface or the facing surface, and it is
possible to efficiently prevent deposits from adhering.
[0047] When the porous supplying portion is to be impregnated with
the cleaning agent, it is preferable to carry out this operation
under a normal pressure condition when an affinity between the
cleaning agent and the porous material configuring the porous
supplying portion is great, and under a high pressure condition
when the affinity is small.
[0048] The cleaning agent supplying unit further includes a
reservoir in which the cleaning agent is stored, and the cleaning
agent supplying unit may be configured such that the cleaning agent
stored in the reservoir can be supplied to the porous supplying
portion.
[0049] In this case, the cleaning agent can be stored in the
reservoir. Further, it is possible to efficiently supply previously
stored cleaning agent to the porous supplying portion.
[0050] It is possible to employ such a configuration that a passage
for bringing the reservoir and outside into communication with each
other is provided, and the cleaning agent can be replenished from
outside to the reservoir.
DESCRIPTION OF THE EMBODIMENTS
First Embodiment
[0051] A first embodiment of the turbocharger will be described
with reference to the drawings.
[0052] As shown in FIGS. 1 and 2, a turbocharger 1 includes a
compressor housing 2 provided therein with an air flow path 10 in
which an impeller 13 is disposed and a bearing housing 3 for
rotatably supporting a rotor shaft 14 to which the impeller 13 is
connected.
[0053] The air flow path 10 includes a suction port 11 through
which air is sucked toward the impeller 13, and a discharge scroll
chamber 12 which is formed on an outer peripheral side of the
impeller 13 in its circumferential direction, and which guides, to
outside, compressed air discharged from the impeller 13.
[0054] As shown in FIGS. 1 and 2, the compressor housing 2 includes
a shroud surface 221 facing to the impeller 13, and a diffuser
surface 222 extending from the shroud surface 221 toward the
discharge scroll chamber 12.
[0055] The bearing housing 3 includes a facing surface 311 which is
facing to the diffuser surface 222 of the compressor housing 2 and
which forms a diffuser passage 15 between the facing surface 311
and the diffuser surface 222.
[0056] As shown in FIGS. 1 and 2, cleaning agent supplying units 4
and 5 are provided in the diffuser surface 222 of the compressor
housing 2 and the facing surface 311 of the bearing housing 3.
[0057] The cleaning agent supplying units 4 and 5 include porous
supplying portions 41 and 51 made of porous material for forming a
portion of the diffuser surface 222 or the facing surface 311, and
are configured such that cleaning agent 6 for preventing adhesion
of deposits is supplied from the porous supplying portions 41 and
51 to the diffuser surface 222 or the facing surface 311.
[0058] This will be described below in detail.
[0059] As shown in FIG. 1, the turbocharger 1 rotates a turbine by
exhaust gas discharged from an internal combustion engine of a car
or the like, compresses suction air in a compressor utilizing the
rotation force, and sends the compressed air into the internal
combustion engine. Therefore, the turbocharger 1 includes, in an
axial direction, a turbine housing (not shown) on aside opposite to
the compressor housing 2 which configures a hull of the
compressor.
[0060] An exhaust gas flow path in which a turbine impeller is
disposed is formed inside of the turbine housing. The turbine
impeller is fixed to the rotor shaft 14. That is, the impeller 13
of the compressor and the turbine impeller are connected to each
other through the rotor shaft 14. According to this, as the turbine
impeller rotates, the impeller 13 of the compressor rotates.
[0061] As shown in FIG. 1, the compressor housing 2 includes a
cylindrical suction port-forming portion 21 forming the suction
port 11, a shroud portion 22 forming the shroud surface 221 and the
diffuser surface 222, and a discharge scroll chamber-forming
portion 23 forming the discharge scroll chamber 12. The shroud
surface 221 is formed into an annular shape so as to face to the
facing surface 311 of the bearing housing 3. The shroud surface 221
forms the diffuser passage 15 between the shroud surface 221 and
the facing surface 311 of the bearing housing 3.
[0062] The impeller 13 is disposed on an inner peripheral side of
the shroud portion 22 of the compressor housing 2. The impeller 13
includes a hub 131 fixed to the rotor shaft 14 through an axial end
nut 141, and a plurality of blades 132 projecting from an outer
peripheral surface of the hub 131 and arranged in a circumferential
direction. The plurality of blades 132 is disposed to face to the
shroud surface 221 of the compressor housing 2.
[0063] The bearing housing 3 which rotatably and pivotally supports
the rotor shaft 14 is disposed between the compressor housing 2 and
the turbine housing. A substantially disk-shaped flange 33 is
provided on one end of the bearing housing 3 in its axial
direction. The facing surface 311 which is facing to the diffuser
surface 222 of the compressor housing 2 is annularly formed on a
surface of the flange 33 on the side of the compressor.
[0064] As shown in FIGS. 1 and 2, the compressor housing 2 is
provided with the cleaning agent supplying unit 4. The cleaning
agent supplying unit 4 includes the porous supplying portion 41
made of porous material and a reservoir 42 in which the cleaning
agent 6 is stored. The porous supplying portion 41 is formed into
an annular pipe shape having an interior space. The porous
supplying portion 41 is disposed in an annular recess 24 provided
in the diffuser surface 222 of the compressor housing 2. A portion
of the porous supplying portion 41 forms a portion of the diffuser
surface 222 of the compressor housing 2.
[0065] The reservoir 42 is provided in an interior space formed by
the porous supplying portion 41. The liquid cleaning agent 6 is
charged into the reservoir 42. The reservoir 42 and outside are in
communication with each other through an external communication
passage 43 provided in the compressor housing 2. One end of the
external communication passage 43 opens toward outside, and this
opening is closed with a plug 44. The cleaning agent 6 can be
replenished to the reservoir 42 through the external communication
passage 43.
[0066] As shown in FIGS. 1 and 2, the bearing housing 3 is also
provided with a cleaning agent supplying unit 5. The cleaning agent
supplying unit 5 includes a porous supplying portion 51 made of
porous material and a reservoir 52 in which the cleaning agent 6 is
stored. The porous supplying portion 51 is formed into an annular
pipe shape having an interior space. The porous supplying portion
51 is disposed in an annular recess 34 provided in the facing
surface 311 of the bearing housing 3. A portion of the porous
supplying portion 51 forms a portion of the facing surface 311 of
the bearing housing 3.
[0067] The reservoir 52 is provided in an interior space formed by
the porous supplying portion 51. The liquid cleaning agent 6 is
charged into the reservoir 52. The reservoir 52 and outside are in
communication with each other through an external communication
passage 53 provided in the bearing housing 3. One end of the
external communication passage 53 opens toward outside, and this
opening is closed with a plug 54. The cleaning agent 6 can be
replenished to the reservoir 52 through the external communication
passage 53.
[0068] The liquid cleaning agent 6 does not pass through the porous
supplying portions 41 and 51 of the cleaning agent supplying units
4 and 5, and the cleaning agent 6 in a state of gas passes through
the porous supplying portions 41 and 51.
[0069] The cleaning agent supplying units 4 and 5 are configured
such that the liquid cleaning agent 6 is vaporized under a
predetermined condition, the cleaning agent 6 passes through the
porous supplying portions 41 and 51 and the cleaning agent 6 is
supplied to the diffuser surface 222 and the facing surface
311.
[0070] In this embodiment, sintered metal made of porous stainless
steel is used as porous material configuring the porous supplying
portions 41 and 51. Further, SUPER-CHECK CLEANING AGENT produced by
MARKTEC Corporation is used as the cleaning agent 6.
[0071] The cleaning agent supplying units 4 and 5 are configured
such that a temperature of compressed air becomes high (e.g.,
165.degree. C. or higher) in the diffuser passage 15, and vaporized
cleaning agent 6 of a necessary amount is supplied at a temperature
(lower than the above temperature by 5 to 10.degree. C.) slightly
lower than a temperature at which oil from a PCV becomes deposits
and the deposits adhere to the diffuser surface 222 of the
compressor housing 2 or the facing surface 311 of the bearing
housing 3.
[0072] According to this, if an atmosphere temperature of the
turbocharger 1 (on the side of compressor) becomes equal to a
predetermined temperature or higher, the cleaning agent 6 which is
stored in the reservoirs 42 and 52 in its liquid state is
vaporized, passes through the porous supplying portions 41 and 51,
and the cleaning agent 6 is supplied to the diffuser surface 222 of
the compressor housing 2 and the facing surface 311 of the bearing
housing 3. The cleaning agent 6 prevents deposits from adhering to
the diffuser surface 222 and the facing surface 311.
[0073] Next, effects in the turbocharger 1 of this embodiment will
be described.
[0074] In the turbocharger 1 of this embodiment, the diffuser
surface 222 of the compressor housing 2 and the facing surface 311
of the bearing housing 3 are provided with the cleaning agent
supplying units 4 and 5 including the porous supplying portions 41
and 51. The porous supplying portions 41 and 51 are disposed such
that they form portions of the diffuser surface 222 and the facing
surface 311. The cleaning agent supplying units 4 and 5 are
configured such that the cleaning agent 6 for preventing deposits
from adhering is supplied from the porous supplying portions 41 and
51 to the diffuser surface 222 and the facing surface 311.
[0075] Hence, the cleaning agent 6 supplied from the porous
supplying portions 41 and 51 of the cleaning agent supplying units
4 and 5 to the diffuser surface 222 and the facing surface 311 can
prevent deposits from adhering to the diffuser surface 222 of the
compressor housing 2 and the facing surface 311 of the bearing
housing 3. According to this, it is possible to prevent deposits
from adhering to (accumulating on) the diffuser surface 222 and the
facing surface 311, i.e., it is possible to prevent the adhesion
(accumulation) of deposits in the diffuser passage 15 formed
between the diffuser surface 222 and the facing surface 311.
[0076] The porous supplying portions 41 and 51 of the cleaning
agent supplying units 4 and 5 are formed of the porous material,
and form at least portions of the diffuser surface 222 and the
facing surface 311. Hence, the cleaning agent 6 is made to pass
through the porous supplying portions 41 and 51, and the cleaning
agent 6 can easily and directly be supplied from the pores formed
in the porous supplying portions 41 and 51 to the diffuser surface
222 and the facing surface 311 as in this embodiment. According to
this, it is possible to efficiently prevent the adhesion of
deposits which try to accumulate on the diffuser surface 222 and
the facing surface 311.
[0077] In this embodiment, the porous supplying portions 41 and 51
are configured such that the liquid cleaning agent 6 does not pass
through the porous supplying portions, and the cleaning agent 6 in
a gas state passes through the porous supplying portions. The
cleaning agent supplying units 4 and 5 are configured such that the
liquid cleaning agent 6 is vaporized under a predetermined
condition, the cleaning agent 6 passes through the porous supplying
portions 41 and 51 and the cleaning agent 6 is supplied to the
diffuser surface 222 or the facing surface 311. Hence, it is
possible to control the supply of the cleaning agent 6 to the
diffuser surface 222 and the facing surface 311 in accordance with
an atmosphere temperature of the turbocharger 1 (on the side of
compressor) as in this embodiment. According to this, it is
possible to efficiently prevent the adhesion of deposits.
[0078] As described above, according to this embodiment, it is
possible to provide the turbocharger 1 capable of preventing the
adhesion of deposits in the diffuser passage 15.
[0079] In this embodiment, the porous supplying portions 41 and 51
of the cleaning agent supplying units 4 and 5 are configured such
that liquid cleaning agent 6 does not pass through the porous
supplying portions 41 and 51 and the gas cleaning agent 6 passes
through the porous supplying portions, but the porous supplying
portions 41 and 51 may be configured such that they can be
impregnated with the liquid cleaning agent 6, that is, the liquid
cleaning agent 6 can be held in the pores formed in the porous
supplying portions 41 and 51.
[0080] The cleaning agent supplying units 4 and 5 may be configured
such that if an atmosphere temperature of the turbocharger 1 (on
the side of compressor) becomes equal to or higher than a
predetermined temperature, the liquid cleaning agent 6 held in the
pores in the porous supplying portions 41 and 51 are vaporized and
supplied to the diffuser surface 222 of the compressor housing 2
and the facing surface 311 of the bearing housing 3.
[0081] The suction port-forming portion 21, the shroud portion 22
and the discharge scroll chamber-forming portion 23 are integrally
formed and this is used as the compressor housing 2 of the
turbocharger 1. Alternatively, a scroll piece mainly configuring
the suction port-forming portion 21 and the discharge scroll
chamber-forming portion 23, and a shroud piece mainly configuring
the shroud portion 22 are assembled together and this may be used
as the compressor housing 2.
Second Embodiment
[0082] In a second embodiment, configurations of cleaning agent
supplying units 4 and 5 are changed as shown in FIG. 3.
[0083] As shown in FIG. 3, the annular disk-shaped porous supplying
portion 41 is disposed in the recess 24 of the compressor housing 2
such that the porous supplying portion 41 closes an opening of the
recess 24. The reservoir 42 is provided in a space of the recess 24
where the porous supplying portion 41 is not disposed.
[0084] The annular disk-shaped porous supplying portion 51 is
disposed in the recess 34 of the bearing housing 3 such that the
porous supplying portion 51 closes an opening of the recess 34. The
reservoir 52 is provided in a space of the recess 34 where the
porous supplying portion 51 is not disposed.
[0085] Other basic structure and effects are the same as those of
the first embodiment.
Third Embodiment
[0086] In a third embodiment, a configuration of the bearing
housing 3 is changed as shown in FIGS. 4 and 5.
[0087] As shown in FIG. 4, the bearing housing 3 is provided with
the bearing body 32 and the back plate 31 which is disposed between
the bearing body 32 and the compressor housing 2 and which faces to
a portion of the air flow path 10. The bearing body 32 and the back
plate 31 are separated from each other. The facing surface 311 is
formed on a surface of the back plate 31 on the side of the
compressor.
[0088] As shown in FIGS. 4 and 5, the back plate 31 of the bearing
housing 3 is provided with the cleaning agent supplying unit 5. The
porous supplying portion 51 is disposed in the annular recess 34
provided in the facing surface 311 of the back plate 31. The
reservoir 52 and outside are in communication with each other
through the external communication passage 53 provided in the back
plate 31.
[0089] Other basic structure is the same as that of the first
embodiment.
[0090] In the case of the third embodiment also, it is possible to
sufficiently obtain the effect for preventing the adhesion of
deposits in the diffuser passage 15.
[0091] Other basic effects are the same as those of the first
embodiment.
* * * * *