U.S. patent application number 12/919330 was filed with the patent office on 2011-01-13 for cooled housing consisting of a turbine housing and a bearing housing for a turbocharger.
This patent application is currently assigned to CONTINENTAL AUTOMOTIVE GMBH. Invention is credited to Raf Boening, Harmut Claus, Robert Vetter.
Application Number | 20110008158 12/919330 |
Document ID | / |
Family ID | 40578605 |
Filed Date | 2011-01-13 |
United States Patent
Application |
20110008158 |
Kind Code |
A1 |
Boening; Raf ; et
al. |
January 13, 2011 |
COOLED HOUSING CONSISTING OF A TURBINE HOUSING AND A BEARING
HOUSING FOR A TURBOCHARGER
Abstract
A housing of a turbo charger has a turbine housing and a bearing
housing. A cooling jacket is formed of at least one or more shell
elements that are fixed to the outside of the housing and that form
therewith a cavity into which a coolant can be introduced.
Inventors: |
Boening; Raf; (Reiffelbach,
DE) ; Claus; Harmut; (Gruenstadt, DE) ;
Vetter; Robert; (Worms, DE) |
Correspondence
Address: |
LERNER GREENBERG STEMER LLP
P O BOX 2480
HOLLYWOOD
FL
33022-2480
US
|
Assignee: |
CONTINENTAL AUTOMOTIVE GMBH
HANOVER
DE
|
Family ID: |
40578605 |
Appl. No.: |
12/919330 |
Filed: |
October 29, 2008 |
PCT Filed: |
October 29, 2008 |
PCT NO: |
PCT/EP08/64638 |
371 Date: |
August 25, 2010 |
Current U.S.
Class: |
415/200 |
Current CPC
Class: |
F05D 2300/43 20130101;
F05D 2300/614 20130101; F02C 6/12 20130101; F05D 2220/40 20130101;
F01D 25/24 20130101; F01D 25/26 20130101; F05D 2300/603
20130101 |
Class at
Publication: |
415/200 |
International
Class: |
F04D 29/00 20060101
F04D029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 27, 2008 |
DE |
10 2008 011 258.5 |
Claims
1-20. (canceled)
21. A housing for a turbocharger, comprising: a turbine housing
part and a bearing housing part of the turbocharger; a cooling
jacket formed of at least one or more shell elements attached to an
outside of said housing and forming a hollow space together with
said housing for receiving therein a coolant.
22. The housing according to claim 21, wherein said turbine housing
part and said bearing housing part of said housing are integrally
formed in a one-piece part.
23. The housing according to claim 22, wherein said turbine housing
part and said bearing housing part of the housing are formed in a
one-piece casting selected from the group consisting of an aluminum
casting, a gray iron casting, and a steel casting.
24. The housing according to claim 21, wherein said turbine housing
part and said bearing housing part are two separate parts attached
to one another.
25. The housing according to claim 23, wherein one of said turbine
housing part and said bearing housing part is formed with a seat to
be pushed up to the respectively other housing part in order to
join together said housing parts.
26. The housing according to claim 22, wherein each of said turbine
housing part and said bearing housing part is a separate casting
selected from the group consisting of an aluminum casting, a gray
iron casting, and a steel casting.
27. The housing according to claim 21, wherein said shell element
is a cast element.
28. The housing according to claim 27, wherein said shell element
is selected form the group consisting of an aluminum casting, a
gray iron casting, and a steel casting.
29. The housing according to claim 27, wherein said shell element
is a pressure diecasting.
30. The housing according to claim 29, wherein said pressure
diecasting has a thickness of between 2 mm and 3 mm.
31. The housing according to claim 21, wherein said shell element
is a sheet component.
32. The housing according to claim 31, wherein said a sheet
component has a thickness of between 0.8 mm and 2 mm.
33. The housing according to claim 21, wherein said cooling jacket
is formed with at least one inlet connection for coolant into said
hollow space and at least one outlet connection for the
coolant.
34. The housing according to claim 33, wherein said inlet and
outlet connections are disposed adjacent one another or on a common
side of the housing.
35. The housing according to claim 33, which comprises a separating
wall element formed between said inlet and outlet connections.
36. The housing according to claim 33, wherein said inlet and
outlet connections are formed substantially opposite one another on
the housing.
37. The housing according to claim 21, wherein said shell element
is attached to the housing by at least one of welding, soldering,
bolting, screwing, and/or gluing, and wherein said turbine housing
part and/or said bearing housing part are optionally formed with
attachment sections for seating said shell element.
38. The housing according to claim 21, wherein said hollow space is
formed to accommodate coolant in liquid form and/or gaseous
form.
39. The housing according to claim 21, wherein said hollow space is
formed for coolant in the form of cooling water from an engine
connected to a turbocharger in the housing.
40. The housing according to claim 21, which comprises one or more
flow elements disposed in said hollow space and formed on one of
said housing or said shell element.
41. The housing according to claim 21, wherein said shell element
is one of two or more shell elements forming an outer wall of said
cooling jacket.
42. The housing according to claim 21, wherein said shell element
is attached to the housing in a fluid-tight connection.
43. The housing according to claim 21, wherein at least one of said
turbine housing part, said bearing housing part, and said shell
element is formed of steel.
44. The housing according to claim 43, wherein said steel includes
a lightly-alloyed steel.
45. The housing according to claim 21, wherein at least one of said
turbine housing part, said bearing housing part, and said shell
element contain or consist of one or more of plastic and
fiber-bonded material.
46. The housing according to claim 21, wherein said bearing housing
part is formed with one or more infeed lines for cooling a portion
of or an entirety of a bearing assembly mounted in said bearing
housing part.
47. A turbocharger, comprising a housing according to claim 21.
Description
[0001] The invention relates to a cooled housing consisting of a
turbine housing and a bearing housing for a turbocharger and a
turbocharger with such a housing.
[0002] Turbochargers, as they are known from the prior art,
generally have a turbine which is arranged in an exhaust gas
stream. In operation, the turbine, driven by the exhaust gases from
the engine, supplies the drive power for the compressor. The
exhaust gas, which is here fed through an exhaust gas elbow into
the turbine housing, drives the turbine wheel and this in turn a
compressor wheel which is arranged on a shaft together with the
turbine wheel. Here, the shaft is mounted on bearings in a bearing
housing in the turbocharger. By the driving of the compressor via
the turbine, the compressor raises the pressure in the engine's
induction manifold, so that a larger quantity of air passes into
the cylinder during the induction cycle. This means that more
oxygen is available and a larger quantity of fuel can be
burned.
[0003] As a consequence of the high temperatures of the exhaust gas
stream which is fed through the turbocharger, the components of the
turbocharger, in particular the turbine housing, are subject to a
heavy thermal load. It is here possible, for example, that in an
automobile internal combustion engine the exhaust gas can reach
temperatures of up to 1100.degree. C. In particular when operating
under full load or close to full load, this can result in
substantial temperature stresses on the components of the
turbocharger.
[0004] Until now, the prior art has essentially relied on a
suitable choice of materials for the manufacture of the housing
parts for the turbocharger. Here, the selection of materials is
made from the point of view of adequate strength at high
temperatures. This involves the use of materials which are highly
heat-resistant, which in general have high proportions of very
expensive alloying elements, such as for example nickel. The effect
of a high proportion of nickel in the material is that cast
materials can better withstand the high temperatures. However,
nickel has the disadvantage that it is a relatively expensive
material. In the state of the art therefore, efforts are made to
use alternative materials, or combinations of materials, which are
more reasonable in price, but are equally suitable for high
component temperatures and, in particular, do not require high
proportions of expensive alloying elements, such as nickel.
[0005] Furthermore, a known approach in the prior art is to provide
a cast-in cooling water jacket in the turbine housing, to lower the
component temperature appropriately. However, such a jacket has the
disadvantage that it is difficult to manufacture for small
turbochargers, such as those used in vehicles, because an
appropriate core must be provided for it.
[0006] Here, a turbocharger for marine use is known from DE 203 11
703. In this case the turbocharger has a cooled turbine-housing and
bearing-housing. The turbine-housing is here constructed with a
double wall, and is cooled by means of seawater. Further, the
bearing housing has its own additional cooling facility, by which
the bearing housing is cooled by means of a coolant from the
coolant circuit of a connected engine, rather than by seawater as
in the case of the turbine housing.
[0007] In addition, a turbine housing for a turbocharger is known
from DE 100 22 052. In this case the turbine housing has, for
example, a triple-walled construction. Here, the outer housing
consists of several shells together with a welded-on water inlet
and outlet. The outer and middle walls here form a hollow space,
through which a coolant is fed. The inner and middle walls also
form a hollow space, which forms an insulating air gap, whereby a
sliding joint is also arranged in this hollow space to permit
thermally-dependent length compensation between the sheet
components. Here, a wire cushion stabilizes the sliding joint.
[0008] However, the turbine housing has the disadvantage that it
has a complicated construction, due to its triple-walled design.
The result of this is that the turbine housing is expensive to
manufacture and assemble. Apart from this, only the turbine housing
is provided with cooling, but not the bearing housing. The
disadvantage of this is that the functionality of the turbocharger
bearings can be degraded after hot soak conditions.
[0009] Accordingly, it is the objective of the present invention to
provide a housing for a turbocharger with an improved cooling
facility.
[0010] This objective is achieved by a housing with the
characteristics of claim 1.
[0011] Accordingly the invention makes available for a turbocharger
a housing, consisting of a turbine housing and a bearing housing,
where the housing has a cooling jacket which is formed of at least
one, or several, shell element(s) which are affixed to the housing
externally and together with it form a hollow space into which a
coolant can be fed.
[0012] This cooled housing, consisting of a turbine housing and a
bearing housing, has the advantage that it is simple and
cost-effective to manufacture, unlike the triple-walled turbine
housing conforming to the prior art which must be welded together
from three sheet layers. Furthermore, the additional cooling of the
bearing housing makes it possible to maintain the functionality of
the shaft bearing even after hot soak conditions.
[0013] Advantageous forms of embodiment and developments of the
invention derive from the subclaims and from the description which
makes reference to the drawings.
[0014] In accordance with one embodiment of the invention, the
turbine housing and the bearing housing of the combined housing are
constructed as one piece or two pieces. The one-piece form of
embodiment has the advantage that a sealed joint of the turbine
housing to the bearing housing to form one housing can be
eliminated.
[0015] In a further form of embodiment in accordance with the
invention, the turbine housing and/or the bearing housing has an
appropriate seat on which to accommodate the other housing part.
This seat can here take any required form, for example as a
depression or a projection onto which the other housing part is
pushed. By means of this seat, the two housing parts can be simply
aligned and adjusted relative to each other before they are
permanently joined to each other.
[0016] In another form of embodiment of the invention the shell
element concerned can, for the purpose of affixing it to the
housing and to form the cooling jacket, be a sheet component or a
pressure diecasting, for example. A sheet component has the
advantage of a constant thickness, whereby it can be reformed in
order to form the appropriate contour for the cooling jacket. A
pressure diecasting on the other hand needs no reforming but can
also, for example, be designed with a more complex contour.
[0017] In accordance with another form of embodiment of the
invention, the cooling jacket has on it, for example, at least one
inlet connection for letting in a coolant and at least one outlet
connection for letting out the coolant. The inlet and outlet
connections can here be arranged adjacent to one another or on the
same side of the housing, as appropriate. In this case, a
separating wall element can optionally be arranged between the two
connections. This has the advantage of preventing the fresh coolant
which is fed into the cooling jacket from immediately flowing out
again at the neighboring outlet before it has adequately flowed
against the housing.
[0018] In another form of embodiment in accordance with the
invention, the inlet and outlet connections are arranged some way
apart from each other on the cooling jacket, for example on
opposite sides. This has the advantage that no separating wall
element is necessary between the two connections.
[0019] In a further form of embodiment in accordance with the
invention, the shell element concerned can be attached to the
housing by means, for example, of welding, soldering,
bolting/screwing and/or gluing etc. The turbine housing and/or the
bearing housing of the housing can as an option have appropriate
attachment sections, to simplify the seating and attachment of the
shell element concerned. The attachment section can here be of any
desired design, for example in the form of a depression or a step,
a groove or a slot etc., for suitably accommodating the shell
element concerned. The attachment sections can here be in the same
form or different.
[0020] In accordance with another inventive form of embodiment the
coolant used is, for example, cooling water which is diverted off
from an engine connected to the turbocharger in the housing. This
has the advantage that a coolant circuit which is already present
can be utilized.
[0021] In a further form of embodiment in accordance with the
invention, the turbine housing, the bearing housing and/or the
shell element concerned are at least partially or completely
manufactured from plastic(s) and or fiber-bonded material(s). By
this means the joint between the parts forms a suitable seal. Such
plastics or fiber-bonded materials, as applicable, have the
advantage that they are comparatively light, and thus the weight of
the turbocharger can be reduced.
[0022] In another form of embodiment in accordance with the
invention, the bearing housing has at least one or several feed
lines in order to cool a part of, or essentially all of, the
bearing arrangement which is mounted within the bearing housing.
Through these feed lines, coolant is then fed into the region of
the bearing arrangement and, as an option, the used or heated
coolant is also fed off again through an appropriate feed line or
return line, as applicable. This has the advantage that the coolant
can be fed closer to the bearing arrangement, and it is possible
thereby to achieve improved cooling.
[0023] The invention is explained below in more detail by reference
to the exemplary embodiments shown in the schematic figures in the
drawing. These show:
[0024] FIG. 1 a perspective view of a cooled housing on a
turbocharger, consisting of a turbine-housing and a bearing-housing
in accordance with one form of embodiment of the invention;
[0025] FIG. 2 a cross-sectional view at B-B of the cooled
turbine-housing and bearing-housing shown in FIG. 1; and
[0026] FIG. 3 another cross-sectional view at C-C of the cooled
turbine-housing and bearing-housing shown in FIG. 1, in which is
shown a connection for letting in the coolant and a connection for
letting out the coolant.
[0027] An example of a cooled turbocharger housing in accordance
with the invention, consisting of a turbine-housing and
bearing-housing, is explained below by reference to the figures.
Such a turbocharger can be used, for example, in particular in an
automobile or other vehicle.
[0028] The invention's approach is aimed, among other things, at
the integration of the bearing housing and the turbine housing into
one housing component or a casting, where the required cooling of
the turbine housing material and of the bearing arrangement is
effected by a cooling jacket. Here, the cooling jacket is formed of
at least one, two, three or more shell element(s) attached around
the combination housing consisting of the turbine-housing and
bearing-housing, and thereby together with the housing forming a
hollow space into which the coolant can be introduced.
[0029] The objective of the invention is a reduction in the
component temperature for the turbine housing, in order to permit
the use of cheaper materials. At the same time, the bearing housing
should be integrated into the turbine housing and the cooling
jacket extended to areas of the bearing housing which are to be
cooled. By this means it is possible, for example, to maintain the
functionality of the turbocharger bearings even after hot soak
conditions.
[0030] The hollow space which is formed around the actual
turbine-housing and bearing-housing part, in that at least one or
several shell elements is/are attached to the housing, is then
formed in such a way that it is suitable for a coolant to flow
through it and can be extended over the bearing housing area by any
required distance. For example, essentially over the entire bearing
housing part, or over a section of the bearing housing.
[0031] FIG. 1 shows a perspective view of the inventive housing 11
of a turbocharger, consisting of a turbine housing 10 and a bearing
housing 13. Both regions of the housing 10, 13 are here provided
with a cooling jacket 18. In the present case, the turbine housing
section 10 has a facility for actuating a bypass duct 32. In
principle, however, the inventively cooled combination housing 11,
comprising the turbine-housing and bearing-housing 10, 13, is
independent of any such facility for actuating a bypass duct 32. In
principle, any type of turbocharger can be used with a
turbine-housing and bearing-housing 10, 13.
[0032] The cooling jacket 18 in FIG. 1 is, for example, formed of
two shell elements 14, 16. The shell element 14, 16 concerned can,
for example if the turbine-housing and/or bearing-housing 10, 13 is
manufactured from an aluminum alloy or from steel, consist for
example of a sheet which is attached to the turbine-housing and
bearing-housing. To attach it, the shell element 14, 16 concerned
can, for example, be welded or soldered onto the combination
housing 11, or otherwise attached. Here, a shell element 14, 16
made of sheet material can, for example, have a thickness of 0.8 mm
to 2 mm. However, the thickness of the sheet is not restricted to
this range, but can also be chosen to be less or greater, depending
on its function and intended use.
[0033] If the housing 11, consisting of the turbine-housing and
bearing-housing 10, 13 is made of an aluminum alloy, for example,
then the shell element 14, 16 concerned can be made from a pressure
diecasting which can, for example, be welded or soldered with the
aluminum alloy. In this case, the pressure diecasting can, for
example, have a wall thickness in the range of 2 mm to 3 mm or 2.5
mm to 3 mm, as appropriate, where the wall thickness of the
pressure diecasting is not restricted to this range, but can also
chosen to be less or greater, depending on its function and
intended use.
[0034] Depending on whether there is an essentially liquid coolant
or, for example, even a gaseous coolant in the cooling jacket 18,
the shell element 14, 16 concerned will be attached to the
turbine-housing and bearing-housing 10, 13 in a liquid-tight or
gas-tight way, for example welded and/or soldered, in order to
provide a suitable hollow space 12 for the coolant. However, it is
also possible to provide other types of attachment and seals, which
are suitable for joining the shell elements 14, 16 to the housing
11 in a liquid-tight or gas-tight way, as appropriate.
[0035] The turbine-housing and bearing-housing 10, 13, as shown in
FIG. 1, is for example a casting, for example made of an aluminum
alloy or another suitable material or combination of materials,
such as for example cast gray iron. The two shell elements 14, 16,
which in the present example are attached to the turbine-housing
and bearing-housing 10, 13, form the cooling jacket 18 or the
hollow space 12, as applicable, into which the coolant is
introduced. Here, the dimensions of the hollow space 12 are chosen
such as to permit an adequate flow of coolant through it to cool
the housing 11 suitably.
[0036] In the present case, as shown in FIG. 1, the two shell
elements 14, 16 each consist of a sheet. Here, the sheet is
reformed appropriately to form the contour of the cooling jacket
18. After this, the shell elements 14, 16 are attached to the
housing 11, consisting of the turbine-housing and bearing-housing
10, 13.
[0037] As shown in FIG. 1, on the cooling jacket 18 is provided at
least one connection 20 for an inlet and one connection 22 for an
outlet for the coolant. One or both of these connections 20, 22 can
here be formed on an appropriate shell element 14, 16 or can be
attached to it as a separate part. As an alternative to a sheet
component for the shell element 14, 16, an appropriate pressure
diecasting can also be provided. The material for this is chosen so
that it can be suitably attached to the housing 11 or to the
turbine-housing and bearing-housing 10, 13, as appropriate. This
means that the material of the shell elements 14, 16 is chosen such
that it can, for example, be welded and/or soldered to the
turbine-housing and bearing-housing 10, 13. This also applies
correspondingly for the sheet component described above.
[0038] As shown in FIGS. 1-3, appropriate attachment sections 24
can be provided on the housing 11, or its turbine housing part 10
and bearing housing part 10, as appropriate, onto which the shell
elements 14, 16 can be attached. In addition, the shell elements
14, 16 are joined to each other at their ends 26 (dotted line), for
example again by welding and/or soldering, in order to form the
hollow space 18 for the coolant.
[0039] As the coolant, which is fed into the cooling jacket 18 via
the first connection 20, or the inlet connection, use can here be
made of cooling water or some other suitable coolant. Furthermore,
it is possible for example to use as the cooling water cooling
water from the engine, or diverted off from it, as appropriate, or
cooling water can be provided in a separate circuit.
[0040] As shown in FIG. 1, the cooling jacket 18 has, for example,
an inlet connection 20 for introducing the coolant, and an outlet
connection 22 for letting out the coolant. In FIG. 1, the two
connections 20, 22 are in this case arranged as far away from each
other as possible. The connections 20, 22 are, for example,
arranged to lie essentially opposite each other. This has the
advantage that the coolant initially flows into the cooling jacket
18 or the hollow space 12 formed by it, as applicable, through the
inlet connection 20 on one side. The fresh coolant then flows
around the housing 11, or the turbine-housing and bearing-housing
10, 13 as applicable, on both sides to cool it appropriately.
Finally, the used coolant flows out again from the cooling jacket
18 or hollow space 12, as applicable, via the outlet connection 22,
as indicated in FIG. 1 by the arrows.
[0041] Here, the connections 20, 22 can be arranged at the same
height as shown again, for example in the next FIG. 3, or can be
provided at different heights. Further, at least one, two or more
inlet connections 20 and/or outlet connections 22 can be provided,
where the connections 20, 22 can have any required positions
relative to each other, preferably so that the coolant can flow
against the housing 11 or the turbine-housing and bearing-housing
10, 13, as applicable, in a suitable way for cooling purposes, and
can flow out of the cooling jacket 18 again. This applies for all
the forms of embodiment of the invention.
[0042] In an alternative form of embodiment, not illustrated, the
inlet and outlet connections 20, 22 can also, for example, be
arranged on the same side or directly alongside each other, or
close to each other, where the two connections 20, 22 are in this
case essentially separated from each other by, for example, a
separating wall element (not illustrated). The separating wall
element is in this case positioned in the cooling jacket 18 of the
housing 11 in such a way that the coolant essentially flows via the
inlet connection 20 initially into the cooling jacket 18 or its
hollow space 12, and does not immediately flow away again through
the neighboring outlet connection 22, but instead initially flows
against the housing 11 or its turbine-housing and bearing-housing
10, 13, or at least flows partially or mostly around it, as
applicable. When the coolant has mostly flowed around the
turbine-housing and bearing-housing 10, 13, and has thereby for
example absorbed heat from the hot or warm turbine-housing and
bearing-housing 10, 13, it then flows out of the cooling jacket 18
again via the outlet connection 22. As previously described, the
separating wall element serves the purpose of essentially
preventing the fresh coolant from mixing with used or consumed
coolant. In this case, the separating wall element can, for
example, as appropriate be provided on or attached to the
turbine-housing and bearing-housing 10 and/or an appropriate shell
element 14, 16. The shell element can here be arranged and attached
between the inlet and outlet connections 20, 22 in such a way that
it separates them completely or at least partly from one another,
in that the separating wall element is arranged, for example,
between the two connections 20, 22 over the entire length of the
housing 11, or at least over part of the length of the housing
11.
[0043] FIG. 2 illustrates a cross-sectional view at B-B of the
cooled housing 11, consisting of the turbine-housing and
bearing-housing 10, 13 shown in FIG. 1. The turbine housing 10 has,
for example, a seat 15 in the form of a depression, with which it
is pushed onto the bearing housing 13 in order to join the two
housing parts together and adjust or align them, as applicable.
[0044] Further, FIG. 2 shows the two shell elements 14, 16. Each of
the shell elements 14, 16, for example a sheet component after it
has been suitably reformed, is attached to the turbine housing 10
and the bearing housing 13 of the combined housing 11. As an
option, appropriate attachment sections 24 can be provided, for
example in the form of depressions or steps, as appropriate, into
which the ends of the shell elements 14, 16 are inserted and are
attached to the housing 11.
[0045] The attachment sections 24 on the turbine housing 10 are
provided as appropriate, for example in the form of a depression 34
or a step in FIG. 2, into which the shell element 14, 16 concerned
is inserted and is then, for example, welded and/or soldered to the
turbine housing 10. In principle however, other types of attachment
section 24 are also possible, for example the depression 34 can
also be designed in the form of a groove or a slot, into which the
shell element 14, 16 is introduced and, for example, welded.
Furthermore, the attachment sections 24 concerned on the turbine
housing 10 can be the same or different in form, depending on their
function and intended use. This applies for all the forms of
embodiment of the invention.
[0046] As shown in FIG. 2, the turbine housing 10 and the bearing
housing 13 are initially designed as two separate or individual
parts, for example as castings. The two housing parts 10, 13 are
put together and attached to each other in such a way that there
can be no unwanted penetration of coolant between them. Depending
on whether the coolant is present in the cooling jacket as a liquid
or at least partially in gaseous form, the two housing parts 10, 13
will be joined together to be liquid-tight or gas-tight, for
example by means of welding, soldering and/or bolting/screwing,
where in the case of bolting/screwing an additional suitable seal
is provided between the housing parts 10, 13. Alternatively, the
turbine housing 10 and the bearing housing 13 can also be designed
in one piece, for example in the form of a unified casting (not
shown). As in the case of the two housing parts 10, 13, the shell
elements 14, 16 are also attached to the housing parts 10, 13 in a
liquid-tight or gas-tight way, as previously described, depending
for example on the state in which the coolant is present in the
cooling jacket 18.
[0047] As an option, at least one, two or more additional flow
elements 28 can be provided in the interior of the cooling jacket
18, for example to guide a liquid coolant. The two flow elements 28
can then each be constructed, for example, in the form of a rib
which, for example, extends in an axial direction, as indicated in
highly simplified form in FIG. 2 by a dashed line. In principle,
the flow element 28 concerned can be constructed and oriented in
any desired way for suitably directing the flow of coolant. The
flow elements 28 can in this case be constructed on the
turbine-housing and/or the bearing-housing, 10, 13, or for example
can be included as part of their shaping or attached to them, as
applicable, and/or provided on the inner side of the appropriate
shell element 14, 16 or attached to it or formed on it, as
appropriate. The provision of flow elements 28 is an optional
feature. This applies for all the forms of embodiment of the
invention.
[0048] FIG. 3 shows a cross-sectional view at C-C of the housing 11
consisting of the turbine-housing and bearing-housing 10, 13 shown
in FIG. 1, and shows both the inlet and the outlet connection 20,
22, for introducing and drawing off the coolant, which lie opposite
each other.
[0049] In addition, the inlet connection 20 is, for example,
provided on the second shell element 16. In principle however, it
would be possible for only one of the connections 20, 22 to be
attacked to one of the shell elements 14, 16. The two connections
20, 22 are here, for example, attached separately to the shell
element 14, 16 concerned, or formed into it, as applicable, and as
shown in FIGS. 1 and 3 are provided, for example, with an
additional connection element 36 or a connection cap, as
appropriate.
[0050] For the purpose of cooling the bearing arrangement (not
illustrated), arranged in the bearing housing 13, two infeed lines
38 are provided, for example, via which the coolant is fed into the
region 40 of the bearing arrangement in order to cool it. In
principle, the inventive cooling jacket 18 can be applied to any
type of cooling of a bearing arrangement in a bearing housing 13
and to any type of infeed line 38 for the bearing arrangement
coolant. The illustration in FIG. 3 is solely by way of example,
and the invention is not restricted to it.
[0051] In the present case, as it is shown in FIGS. 1 to 3, the
cooling jacket 18 extends over the turbine housing 10 and
essentially over the entire bearing housing 13. In principle
however, the cooling mantle can also extend over only a part of the
turbine housing 10 and/or the bearing housing 13, depending on
which part or section is to be additionally cooled.
[0052] The advantage of the inventive form of embodiment described
above, in particular relative to a form of embodiment with a
cast-in cooling jacket, is that the cooling jacket 18 can also be
realized for very a small automobile turbine housing 10, because it
does not require the use of core elements. Apart from this, it
permits a reduction in the number of components in the
turbocharger, the possible reduction to one coolant inflow and
outflow for a cooled region of a turbine-housing and
bearing-housing.
[0053] Although the present invention has been described above by
reference to preferred exemplary embodiments, it is not restricted
to them but can be modified in diverse ways. The forms of
embodiment described above, in particular individual features of
them, can here be combined with each other.
[0054] The coolant, such as for example cooling water for cooling
the housing 11, can as already described be taken from a cooling
circuit of an engine which is linked to the turbocharger. The
cooling circuit here comprises, for example, an engine block, a
thermostat, a radiator and a coolant pump. After cooling the
housing 11, the coolant can be fed back to the cooling circuit.
However, the invention is not restricted to this form of embodiment
of a cooling circuit.
[0055] The provision of the cooling jacket 18 for cooling the
housing 11 enables the latter to be made of less heat-resistant
materials. For example, the housing 11 concerned can incorporate
materials such as more lightly alloyed steels, aluminum, cast gray
iron etc. By this means, it is possible to eliminate the use of
expensive alloying elements such as for example nickel, or their
proportions can at least be reduced. This has the further advantage
that the manufacturing costs can be reduced.
[0056] Apart from this, it is possible to effect the engineering of
the turbine housing 10, the bearing housing and/or the shell
elements 14, 16 concerned not only in iron or non-ferrous metals,
but also in plastic(s) and/or fiber-bonded material(s). In this
case, the plastics or fiber-bonded materials, as applicable, are
chosen such that they are suitable for the relevant temperatures
which will arise in the turbine housing 10 or bearing housing 13 or
shell elements 14, 16 constructed from them.
[0057] In this case, the turbine housing 10 or the bearing housing
13 and the shell elements 14, 16 concerned will be appropriately
jointed, for example by means of welding, soldering,
bolting/screwing with a seal between the shell elements 14, 16
concerned and the housing 11, and/or gluing, to name just some
methods of attachment. The shell elements 14, 16 can each be
manufactured from the same material or a different material,
depending on their function and intended use. The same applies for
the turbine housing 10 and the bearing housing 13.
[0058] Apart from the cooling function of the cooling jacket 18, by
the introduction of the coolant, it is also possible for example to
use the cooling jacket 18 for heating purposes, if for example the
turbine housing 10 and bearing housing 13 should be warmed up or
prewarmed to an operating state. In this case it is possible, for
example, to use cooling water which has already been heated up by
the engine, and introduce it into the cooling jacket 18.
* * * * *