U.S. patent application number 14/106745 was filed with the patent office on 2014-04-10 for turbine for an exhaust gas turbocharger.
This patent application is currently assigned to IHI CHARGING SYSTEMS INTERNATIONAL GMBH. The applicant listed for this patent is IHI CHARGING SYSTEMS INTERNATIONAL GMBH. Invention is credited to Thorben KOTZBACHER.
Application Number | 20140099191 14/106745 |
Document ID | / |
Family ID | 46458422 |
Filed Date | 2014-04-10 |
United States Patent
Application |
20140099191 |
Kind Code |
A1 |
KOTZBACHER; Thorben |
April 10, 2014 |
TURBINE FOR AN EXHAUST GAS TURBOCHARGER
Abstract
In a turbine for exhaust gas turbocharger of a combustion engine
with a turbine casing forming an installation space in which a
turbine wheel is arranged so as to be rotatable about an axis of
rotation and into which exhaust gas of the combustion engine may be
supplied via at least one flow duct in which a guide vane structure
is arranged, the guide vane structure includes vanes, which are
pivotably supported relative to the turbine casing and form an
axial inlet nozzle structure adjacent a wall portion of the turbine
which extends along the guide vane structure, the wall portion
comprising at least a first guide wall area which overlaps the
guide vane structure, and which is set back relative to a second
guide wall area in which the vanes are pivotably supported and
which adjoins the first wall area.
Inventors: |
KOTZBACHER; Thorben;
(Heidelberg, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IHI CHARGING SYSTEMS INTERNATIONAL GMBH |
Heidelberg |
|
DE |
|
|
Assignee: |
IHI CHARGING SYSTEMS INTERNATIONAL
GMBH
Heidelberg
DE
|
Family ID: |
46458422 |
Appl. No.: |
14/106745 |
Filed: |
December 14, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/EP2012/002637 |
Jun 22, 2012 |
|
|
|
14106745 |
|
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Current U.S.
Class: |
415/159 ;
415/151 |
Current CPC
Class: |
F02B 37/24 20130101;
Y02T 10/144 20130101; F02C 6/12 20130101; F01D 17/165 20130101;
F01D 17/16 20130101; F05D 2220/40 20130101; Y02T 10/12
20130101 |
Class at
Publication: |
415/159 ;
415/151 |
International
Class: |
F01D 17/16 20060101
F01D017/16 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 20, 2011 |
DE |
10 2011 108 195.3 |
Claims
1. A turbine for an exhaust gas turbocharger of a combustion
engine, comprising a turbine casing (14) including an installation
space (18), a turbine wheel (20) arranged in the installation space
(18) so as to be rotatable about an axis of rotation (22) at least
one inlet flow duct (38) via which exhaust gas of the combustion
engine may be supplied to the turbine wheel (20), a guide vane
structure (72) arranged in the inlet flow duct (38) and including
vanes which are pivotably supported relative to the turbine casing
(14), the vane structure (72) being delimited in the axial
direction of the installation space (18) at least partially by at
least one wall portion (70) of the turbine (12) which is at least
partially overlapping the guide vane structure (72), the wall
portion (70) comprising a first wall area (80) which is arranged
adjacent the guide vane (72), and which is set back relative to a
second wall area (82) of the wall portion (70) adjoining the first
wall area (80).
2. The turbine according to claim 1, wherein the wall portion (70)
with the first wall area (80) and the second wall area (82) is
arranged at the side of the guide vane structure (72) facing the
turbine wheel outlet area (52) of the turbine (12).
3. The turbine according to claim 1, wherein the first wall area
(80) and the second wall area (82) are joined via a third wall area
(84) of the wall portion (70), which is arranged between the first
wall area (80) and the second wall area (82), and forms with the
first wall area (80) and the second wall area (82) an angle of
essentially 90.degree..
4. The turbine according to claim 1, wherein the first wall area
(80) and the second wall area (82) are joined via a third wall area
(84) of the wall portion (70), which extends between the first wall
area (80) and the second wall area (82), and is essentially
arc-shaped.
5. The turbine according to claim 1, wherein the wall portion (70)
is in the form of a cover plate (70), which is an insert component
formed separately from the turbine casing (14) and which is at
least partially accommodated in the installation space (18), and
which extends at least over part of the blade edges (48) of the
turbine wheel (20).
6. The turbine according to claim 5, wherein the cover plate (70)
has a cover contour (74) which is essentially complementary to the
contour of the blade edges (48).
7. The turbine according to claim 1, wherein the guide vane
structure (72) abuts a retaining component which is formed
separately from the turbine casing (14), in the form of a nozzle
ring (66) which is supported in the turbine casing (14).
Description
[0001] This is a Continuation-in-Part application of pending
international patent application PCT/EP2012/002637 filed Jun. 22,
2012 and claiming the priority of German patent application 10 2011
108 195.3 filed Jul. 20, 2011.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a turbine for an exhaust
gas turbocharger including a turbine casing with a turbine wheel
rotatably disposed therein and guide vanes which are adjustably
supported for controlling the exhaust gas flow to the turbine
wheel.
[0003] DE 10 2008 034 751 A1 discloses a turbocharger for a
combustion engine with a turbine casing and a turbine comprising a
turbine wheel arranged therein, wherein the turbine is equipped
with adjustable guide vanes for varying a flow cross-section via
which the exhaust gas is directed onto the turbine wheel. A
floating spacer ring is provided between the adjustable guide vanes
and the turbine casing, which is in contact with the incoming
exhaust gas via a pressure duct, and the rear side of which may be
exposed to the exhaust gas. During operation of the turbocharger, a
force resultant is generated which acts axially upon the spacer
ring and pushes the spacer ring against the end faces of the guide
vanes by this force resultant.
[0004] It is the object of the present invention to provide a
turbine for an exhaust gas turbocharger with an improved
variability or adjustability, respectively.
SUMMARY OF THE INVENTION
[0005] In a turbine for an exhaust gas turbocharger of a combustion
engine with a turbine casing forming an installation space in which
a turbine wheel is arranged so as to be rotatable about an axis of
rotation and into which exhaust gas of the combustion engine may be
supplied via at least one flow duct in which a guide vane structure
is arranged, the guide vane structure includes vanes, which are
pivotably supported relative to the turbine casing and form an
axial inlet nozzle structure adjacent a wall portion of the turbine
which extends along the guide vane structure, the wall portion
comprising at least a first guide wall area which overlaps the
guide vane structure, and which is set back relative to a second
guide wall area in which the vanes are pivotably supported and
which adjoins the first wall area.
[0006] Such a turbine for an exhaust gas turbocharger of a
combustion engine comprises a turbine casing which at least
partially defines an installation space in which a turbine wheel
may be arranged so as to be rotatable about an axis of rotation
relative to the turbine casing. Exhaust gas of the combustion
engine may be supplied to the installation space via at least one
flow duct in which a guide vane structure is arranged which is
movable relative to the turbine casing. The flow duct is defined in
the axial direction of the installation space and thus of the
turbine wheel at least partially by at least one wall portion of
the turbine which is at least partially overlapping the guide vane.
In other words, the second wall area is closer to the guide vane
than the first wall area. Therefore, the wall areas do not extend
in a common plane. Rather, the wall areas extend e. g. in two
different planes which are arranged in the axial direction on
different levels, and which e. g. at least essentially extend
parallel to each other and/or which e. g. at least essentially
extend vertically to the axial direction.
[0007] Because of this special design of the wall portion, in
particular of the outer contour facing towards the guide vane, the
inventive turbine exhibits especially low friction and an improved
variability or adjustability, respectively. In particular, the
guide vanes may be moved with very low friction and thus operate
extremely smoothly, in order to variably establish proper flow
conditions for the exhaust gas of the combustion engine entering
the flow duct and to precisely adapt the vane positions to
different operating points of the combustion engine. This results
in an improved operability which keeps the fuel consumption and the
CO.sub.2 emission of the combustion engine low.
[0008] The guide vanes are, for example, pivotable about a pivot
axis relative to the turbine casing in order to e. g. adjust a flow
cross-section of the inlet flow duct for the exhaust gas. This
means that the flow cross-section may be at least partially fluidly
blocked or unblocked.
[0009] Since the first wall area is set back relative to the second
wall area, the inventive turbine exhibits extremely low friction
when the guide vane is at least partially opened. This is
accompanied by a low hysteresis which in turn enhances the
efficient operation and a high efficiency of the turbine.
[0010] Since the first wall area is set back relative to at least
the second wall area, the inventive turbine, in particular with
opened guide vane, has an extremely high absorption capacity, so
that a high exhaust gas mass flow may pass the turbine. In the
upper load and/or speed ranges and thus at high exhaust gas mass
flow, the inventive turbine allows a particularly efficient
operation of the combustion engine and the realisation of
particularly high power and/or torque values, because it permits an
extremely high exhaust gas mass flow. The turbine does not
represent an undesired high flow resistance for the high exhaust
gas mass flow, so that charge changing losses are kept particularly
small. This enhances the fuel-efficient operation of the combustion
engine and is accompanied by low CO.sub.2 emission.
[0011] The inventive turbine further comprises a particularly
advantageous controllability when installed on a combustion engine,
so that the latter can be particularly efficiently operated.
Moreover, no negative effects on the efficiency of the turbine and
the exhaust gas turbocharger in low speed and/or load ranges occur,
so that the inventive turbine provides for a fuel-efficient
operation of the combustion engine almost in the entire operating
range.
[0012] Another advantage of the set-back of the first wall area is
that it results in an advantageously low acceleration between the
guide vane and the turbine wheel. The inventive turbine may be
employed for combustion engines in the form of gasoline engines or
diesel engines, which are reciprocating engines. It may also be
employed for other combustion engines which are operated e. g. with
gaseous and/or liquid fuels.
[0013] In an advantageous embodiment of the invention, the wall
portion with the wall areas is arranged on the side facing the
turbine wheel outlet area of the turbine of the guide vane. In
other words, the flow duct through the wall portion with the two
appropriately formed wall areas is arranged on the side facing the
turbine wheel outlet area of the turbine. Thereby, the friction of
the inventive turbine, in particular with the at least partially
opened guide vane, may be kept extremely low, which in turn is
beneficial for the wear of the inventive turbine.
[0014] In a particularly advantageous embodiment of the invention,
the first and second wall areas are joined via a third wall area of
the wall portion, which is arranged between the first and second
wall area. The third wall area extends at an angle of essentially
90.degree. max, each between the first and second wall area. This
means that a transition area between the first and second wall area
is formed essentially step-shaped. This allows advantageous flow
conditions for the exhaust gas flowing through the flow duct, which
brings about a particularly high efficiency of the inventive
turbine. At the same time, the manufacturing costs for the
inventive turbine are kept low, which in turn is accompanied by low
costs for the entire combustion engine.
[0015] In another particularly advantageous embodiment of the
invention, the third wall area is formed essentially arc-shaped, in
particular in the radial direction of the installation space thus
of the turbine wheel. This enables favourable flow conditions for
the exhaust gas through the flow duct. In particular, turbulences
and/or other negative effects for an efficient flow of the exhaust
gas into the installation space may be avoided. This contributes to
a particularly high efficiency and a particularly efficient
operation of the inventive turbine.
[0016] The appropriate design of the first and second wall area as
well as, in particular, of the third wall area disposed
therebetween has to be adapted to the corresponding requirements
and applications. The inventive turbine may be employed, for
example, in a combustion engine for a passenger car as well as in a
combustion engine for a commercial motor vehicle or another motor
vehicle.
[0017] In another advantageous embodiment of the invention, the
first wall area, with the turbine wheel of the turbine arranged at
least partially in the installation space, extends at least in the
radial direction of the installation space and thus of the turbine
wheel at least to the level of the leading edge of a rotor blade of
the turbine wheel. The exhaust gas is conveyed to the rotor blade
and thus the turbine wheel across the leading edge, with the
leading edge extending e. g. at least essentially in the axial
direction of the installation space and thus of the turbine wheel.
By this design of the first wall area which is set back relative to
the second wall area, the first wall area preferably has a
particularly long radial extension which contributes to
particularly low friction and an advantageous operability and a
particularly advantageous operation of the inventive turbine.
[0018] Preferably, the second wall area adjoins the first wall area
at least in the radial direction of the installation space and the
turbine wheel. This means that starting from the installation space
towards the flow duct, at first the first wall area is provided
followed by the second wall area. This contributes to a
particularly high efficiency of the inventive turbine.
[0019] In another advantageous embodiment of the invention, the
wall portion is formed by a cover element, in particular a cover
plate, of the turbine, which is an insert component which is formed
separately from the turbine casing is arranged at least partially
in the installation space and by means of which at least one
leading edge, in particular a blade edge of the rotor blade of the
turbine wheel which is at least partially arranged in the
installation space may be at least partially covered or is covered,
respectively. Thereby, particularly favorable and advantageous flow
conditions for the exhaust gas flowing through the turbine and in
particular through the flow duct may be realised, which in turn
enhances the efficient operation and the efficiency of the
inventive turbine.
[0020] Further, the provision of the insert component enables a
particularly simple and cost-efficient manufacture and assembly of
the inventive turbine, which keeps the costs of the entire
combustion engine low.
[0021] It may be provided that the guide vane is held movable, in
particular pivotable, about the pivot axis, on the cover element
relative to the turbine casing and the cover element. This enhances
a simple and cost-efficient assembly of the inventive turbine.
[0022] Preferably, the cover element has a cover contour by means
of which the leading edge, in particular the blade edge, is at
least partially covered and which is formed at least partially as
an at least essentially corresponding complementary contour to the
outer contour of the leading edge. Thereby, a particularly
advantageous cover of the leading edge, in particular of the blade
edge, may be realized. This generates particularly advantageous
flow conditions for the exhaust gas flowing to and flowing off the
turbine wheel or its rotor blades, respectively. Thereby, the
inventive turbine exhibits a particularly efficient operation and a
particularly high efficiency, which enhances an efficient and
fuel-efficient operation of the combustion engine.
[0023] In another advantageous embodiment of the invention, the
guide vanes are supported by a retaining component which is formed
separately from the turbine casing, in particular on a nozzle ring,
wherein the retaining component is an insert component, which is
accommodated in the turbine casing. This enables a particularly
simple, time-saving and cost-efficient assembly of the inventive
turbine as well as a particularly cost-efficient manufacture.
[0024] Further advantages, features and details of the invention
will become apparent from the following description of preferred
exemplary embodiments with reference to the accompanying drawings.
The features and feature combinations as previously mentioned in
the description as well as the features and feature combinations
which will be mentioned in the following description of the figures
and/or which are solely illustrated in the figures are not only
applicable in the respective indicated combination but also in
other combinations or isolated, without deviating from the scope of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is an axial cross-sectional view of part of an
exhaust gas internal combustion engine;
[0026] FIG. 2 is another and enlarged schematic longitudinal
sectional view showing portions of the exhaust gas turbocharger
according to FIG. 1;
[0027] FIG. 3 shows portions of a schematic longitudinal sectional
view of still another embodiment of the exhaust gas turbocharger
according to FIG. 2; and
[0028] FIG. 4 shows portions of a schematic longitudinal sectional
view of another embodiment of the exhaust gas turbocharger
according to FIGS. 2 and 3.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0029] FIG. 1 shows an exhaust gas turbocharger 10 for a combustion
engine which is in the form for example of a reciprocating piston
engine. The exhaust gas turbocharger 10 comprises a turbine 12 with
a turbine casing 14 which houses a turbine wheel 20 and comprises a
spiral duct 16 through which the exhaust gas of the combustion
engine is supplied to the turbine wheel 20. The spiral duct 16 is
fluidly connected with at least one cylinder of the combustion
engine so that exhaust gas from the cylinder may enter the spiral
duct 16.
[0030] The turbine casing 14 also at least partially defines an
installation space 18 in which the turbine wheel 20 of the turbine
12 is accommodated. The turbine wheel 20 is arranged in the
installation space 18 and rotatable about an axis of rotation 22
relative to the turbine casing 14.
[0031] The turbine wheel 20 is part of a rotor 24 of the exhaust
gas turbocharger 10, which comprises a shaft 26. The turbine wheel
20 is non-rotatably connected to the shaft 26 which is r supported
in a bearing housing 28 of the exhaust gas turbocharger 10 so as to
be rotatable about the axis of rotation 22 relative to the turbine
casing 12 and the bearing housing 28. The turbine casing 14 and the
bearing housing 28 are connected to each other.
[0032] The rotor 24 also comprises a compressor wheel 30 of a
compressor 32 of the exhaust gas turbocharger 10. The compressor
wheel 30 is also non-rotatably connected to the shaft 26. The
compressor 32 comprises a compressor casing 34 which is also
securely connected to the bearing housing 28 and by which an
installation space 36 is at least partially defined in which the
compressor wheel 30 which is supported rotatably about the axis of
rotation 22 relative to the compressor casing 34 is at least
partially accommodated.
[0033] The exhaust gas flowing through the spiral duct 16 is guided
by the spiral duct 16 to a nozzle 38 of the turbine 12, via which
the exhaust gas may flow at least essentially in the radial
direction to, and impinge on, the turbine wheel 20. This is
indicated in FIG. 1 by a direction arrow 40. The turbine wheel 20
comprises a hub body 42 provided with a plurality of rotor blades
44. The rotor blades 44 are arranged at least essentially equally
spaced about the circumference of the turbine wheel 20 and securely
connected to the hub body 42. FIG. 1 shows only one of the
pluralities of rotor blades 44.
[0034] The rotor blade 44 comprises a leading edge 46 which extends
at least essentially in the axial direction, via which the turbine
wheel 20 is exposed to the exhaust gas flow. The rotor blade 44
further has a blade edge 48 and a trailing edge 50 via which the
exhaust gas may flow off the turbine wheel 20 or the rotor blade
44, respectively. In other words, the exhaust gas flows across the
leading edge 46 onto the turbine wheel 20 or its rotor blades 44,
respectively, and flows off at least essentially past the trailing
edge 50 into a turbine wheel outlet area 52. The radial direction
of the installation space 18 and thus of the turbine wheel 20 or of
the turbine 12, respectively, is indicated in FIG. 1 by a direction
arrow 54, while the axial direction is indicated by a direction
arrow 56 in FIG. 1.
[0035] By this application of the exhaust gas, the turbine wheel 20
rotates about the axis of rotation 22, which in turn rotates the
shaft 26 as well as the compressor wheel 30 about the axis of
rotation 22. The turbine 12 is a radial turbine and drives the
compressor 32, which is a radial compressor that takes in and
compresses air. The sucked-in air flows across a leading edge 58 of
a compressor blade 60 of the compressor wheel 30 and flows off
across a trailing edge 62 of the compressor blade 60. The
compressed air is then guided through a compressor spiral duct 64
which is formed by the compressor casing 34 to the at least one
cylinder of the combustion engine.
[0036] As can be seen from FIG. 1, the nozzle 38 extension in the
axial direction of the turbine 12 or of the installation space 18,
respectively, (direction arrow 56) at the side facing the bearing
housing 28 is delimited at least partially by a nozzle ring 66. The
nozzle ring 66 is formed as a separate insert component relative to
the turbine casing 14 and accommodated in the turbine casing 14.
For fixing the nozzle ring 66 in place relative to the turbine
casing 14, a mounting ring 68 is provided, by which the nozzle ring
66 is retained. The mounting ring 68 is arranged in the axial
direction between the turbine casing 14 and the bearing housing 28
and clamped between them. In this manner, the nozzle ring 66 may be
indirectly supported by the turbine casing 14 via the mounting ring
68 in a spaced relationship to turbine casing 14 and secured
relative thereto.
[0037] At the side facing the turbine wheel outlet area 52, the
nozzle 38 is at least partially defined by a cover plate 70. The
cover plate 70 is in the form of an insert component separate from
the turbine casing 14 and arranged at least partially in the
installation space 18. Thus, the cover plate 70 acts as wall
portion which delimits the nozzle 38 in the axial direction of the
installation space 18 and thus of the turbine 12 at the side facing
the turbine wheel outlet area 52.
[0038] Moreover, as shown in FIG. 1, guide vanes 72 are supported
in the turbine casing 14 between the cover plate 70 and the nozzle
ring 66 so as to be pivotable about an axis 76, which extends at
least essentially in the axial direction and thus essentially
parallel to the axis of rotation 22. This allows a variable
adjustment of the flow cross-section of the nozzle 38, through
which the exhaust gas of the combustion engine flows from the
spiral duct 16 to the turbine wheel 20. This permits to adjust the
turbine 12 to different operating or load points, respectively, of
the combustion engine as required, so that the turbine 12 and thus
the entire exhaust gas turbocharger 10 may be operated particularly
efficiently.
[0039] As can be seen, in particular in conjunction with FIG. 2,
the trailing edge 48 of the rotor blade 44 is at least partially,
in particular completely, covered or overlapped by the cover plate
70. The exhaust gas can therefore mainly, in particular
exclusively, flow off the rotor blade 44 across the trailing end
50. This provides for particularly advantageous flow conditions for
the exhaust gas entering the turbine wheel 20. The cover plate 70
comprises an outer contour 74 around the trailing edge 48 which at
least essentially corresponds to the shape of the blade edge
48.
[0040] In FIG. 2, the pivot axis 76 can be seen, about which the
guide vane 72 may be pivoted. The guide vane 72 is supported
pivotably about the pivot axis 76 by the cover plate 70 and the
nozzle by bearing journals 78 connected to the guide vane. The
bearing journals 78 are seated at least partially in corresponding
seats of the cover plate 70 and the nozzle ring 66.
[0041] As shown in particular in FIG. 2, the cover plate 70
comprises, in the radial direction of the turbine 12 starting from
the axis of rotation 22, a first wall area 80 as well as a second
wall area 82 adjoining the first wall area in the radial direction.
The first wall area 80 which in the axial direction at least
partially overlaps the guide vane 72 is set back relative to the
second wall area 82 which in the axial direction at least partially
overlaps the guide vane 72. In other words, this means that the
second wall area 82 in the axial direction is closer to the guide
vane 72 than the first wall area 80. The first wall area 80 extends
in the radial inward direction at least essentially to the same
level as the leading edge 46 of the rotor blade 44. Thereby, the
turbine 12 exhibits an extremely low hysteresis, in particular when
the guide vane 72 is at least partially opened that is in a
position which opens the flow cross-section of the nozzle 38
partially.
[0042] The first wall area 80 and the second wall area 82 are
joined via a third wall area 84, wherein the third wall area 84 is
arranged between the first wall area 80 and the second wall area
82. In a first exemplary embodiment, the third wall area 84 extends
at an angle of essentially 90.degree. each between the first wall
area 80 and second wall area 82. This means that the first wall
area 80, the second wall area 82 and the third wall area 84 are
arranged and formed at least essentially step-shaped.
[0043] FIG. 3 shows an exemplary embodiment of the exhaust gas
turbocharger 10 different from that of FIGS. 1 and 2, Whereas the
third wall area 84 according to FIG. 2 extends essentially parallel
to the axial direction (direction arrow 56) and includes an angle
of essentially 90.degree. with the radial direction (direction
arrow 54), the third wall area 84 according to FIG. 3 extends
obliquely to the axial direction at an angle with the radial
direction different from 90.degree.. Likewise, the third wall area
84 includes an angle different from 90.degree. both with respect to
the first wall area 80 and the second wall area 82. The third wall
area 84 is formed straight, i. e. not arc-shaped, round or the
like.
[0044] FIG. 4 shows still another exemplary embodiment of the
exhaust gas turbocharger 10 according to FIGS. 1 to 3. As can be
seen from FIG. 4, the third wall area 84 is formed at least
essentially arc-shaped in the radial direction (direction arrow
54).
[0045] The appropriate design of the first wall area 80, the second
wall area 82 and the third wall area 84 may be adapted to the
requirements and particular applications. In particular, the
respective radial extension (length) and/or axial extension (depth
of the first wall area 80, the second wall area 82 and the third
wall area 84) may be appropriately dimensioned and varied and
deviate from the corresponding extensions shown in FIGS. 2 to 4.
also contours of the first wall area 80, the second wall area 82
and the third wall area 84 may be provided which are different from
those shown in FIGS. 2 to 4.
* * * * *