U.S. patent application number 13/048467 was filed with the patent office on 2011-09-22 for rotor for a charging device.
Invention is credited to Thomas Berger, Klaus Czerwinski, Oliver Gamm, Martin Schlegl.
Application Number | 20110229325 13/048467 |
Document ID | / |
Family ID | 43797821 |
Filed Date | 2011-09-22 |
United States Patent
Application |
20110229325 |
Kind Code |
A1 |
Czerwinski; Klaus ; et
al. |
September 22, 2011 |
ROTOR FOR A CHARGING DEVICE
Abstract
A rotor for a charging device may include a shaft, a turbine
wheel and a compressor wheel. The turbine wheel may be connected to
the shaft. The rotor may also include at least one of a metal or
ceramic adapter connected to the turbine wheel or the shaft via an
infiltration process.
Inventors: |
Czerwinski; Klaus;
(Heimsheim, DE) ; Schlegl; Martin; (Rudersberg,
DE) ; Berger; Thomas; (Ditzingen, DE) ; Gamm;
Oliver; (Eislingen, DE) |
Family ID: |
43797821 |
Appl. No.: |
13/048467 |
Filed: |
March 15, 2011 |
Current U.S.
Class: |
416/171 |
Current CPC
Class: |
F01D 5/284 20130101;
F05D 2300/21 20130101; F01D 5/025 20130101; F01D 5/063 20130101;
F05D 2220/40 20130101 |
Class at
Publication: |
416/171 |
International
Class: |
F01D 25/00 20060101
F01D025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 16, 2010 |
DE |
102010011486.3 |
Claims
1. A rotor for a charging device comprising: a shaft, a turbine
wheel and a compressor wheel, wherein the turbine wheel is
connected to the shaft, at least one of a metal or ceramic adapter
connected to the turbine wheel and the shaft via an infiltration
process.
2. The rotor according to claim 1, wherein the adapter is sintered
onto at least one of the turbine wheel and the shaft.
3. The rotor according to claim 1, wherein the adapter is a metal
adapter and connected to at least one of the shaft and the turbine
wheel.
4. The rotor according to claim 3, wherein the adapter is welded to
at least one of the shaft and the turbine wheel.
5. The rotor according to claim 1, wherein the adapter has at least
one of an annular shape and a disc-like-shape.
6. The rotor according to claim 1, wherein the adapter is
integrated in a back of the turbine wheel.
7. The rotor according to claim 1, wherein the rotor is disposed in
an exhaust gas turbocharger.
8. A rotor for a charging device comprising: a shaft, a turbine
wheel and a compressor wheel, the turbine wheel being connected to
the shaft, a plurality of webs extending radially away to the
outside of and arranged on the shaft, and longitudinal webs
extending radially away to the outside of the shaft and being
arranged on a receiving opening of the turbine wheel, the webs and
longitudinal webs configured to deformed when the turbine wheel is
slid onto the shaft.
9. The rotor according to claim 8, wherein the webs are designed as
at least one of the longitudinal webs and circumferential webs.
10. A rotor for a charging device comprising: a shaft, a turbine
wheel and a compressor wheel, a conically tapering region having an
outer thread arranged on the free end of the shaft, wherein the
turbine wheel has a conical receiving opening formed
complementarily thereto with a following internal thread.
11. The rotor according to claim 1, wherein the adapter is sintered
onto the turbine wheel.
12. The rotor according to claim 1, wherein the adapter is sintered
onto the shaft.
13. The rotor according to claim 1, wherein the adapter is a metal
adapter and connected to the shaft.
14. The rotor according to claim 1, wherein the adapter is a metal
adapter and connected to the turbine wheel.
15. The rotor according to claim 3, wherein the adapter is brazed
to the shaft.
16. The rotor according to claim 3, wherein the adapter is brazed
to the turbine wheel.
17. The rotor according to claim 1, wherein the adapter has an
annular shape.
18. The rotor according to claim 1, wherein the adapter has a
disc-like-shape.
19. The rotor according to claim 2, wherein the adapter has at
least one of an annular and a disc-like-shape.
20. The rotor according to claim 2, wherein the adapter is
integrated in a back of the turbine wheel.
Description
CROSS-REFERENCES TO RELATED APPLICATION
[0001] This application claims priority to German patent
application DE 10 2010 011 486.3 filed on Mar. 16, 2010, which is
hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to a rotor for a charging
device, more preferably for an exhaust gas turbocharger, with a
shaft carrying a turbine wheel and a compressor wheel according to
the preamble of claim 1. The invention additionally relates to a
charging device equipped with such a rotor. The invention
additionally relates to a rotor for a charging device according to
the preamble of claims 8 and 10.
BACKGROUND
[0003] From DE 10 2004 025 049 A1 a generic rotor is known, wherein
the shaft between a turbine wheel and a mounting comprises at least
one heat insulation whose heat permeability is lower than that of
the regions of the shaft adjoining the heat insulation and which
inhibits the heat passage through the shaft. The intention of this
is to more preferably achieve an improved heat management.
[0004] From EP 1 002 935 A1 a further rotor is known wherein a
turbine wheel via an adapter consists of a nickel or cobalt-based
alloy. In order to be able to reduce an undesirable heat flow from
the turbine wheel to a temperature-sensitive bearing guiding the
steel body of the bearing shaft in the process, the adapter is
constructed of at least two rigidly interconnected cylinder
portions, of which one is formed of the nickel or cobalt-based
alloy and another of a steel with a lower heat conductivity
compared with the material of the steel body.
[0005] Further rotors are known for example from WO 2006/105891 A1
and from U.S. Pat. No. 4,557,704.
[0006] Finally, a rotor wherein a turbine wheel is screwed to a
shaft via a thread is known from DE 10 2007 028 346 A1. Generally,
turbine/compressor wheels are usually connected to a corresponding
shaft by way of thermal joining methods, for example electron beam
or friction welding or brazing. Here, the parts to be joined are
solid and the parts are joined in a manufacturing step that is
separate from the actual parts production. At the joining point of
the turbine/compressor wheel with the shaft, however, a local,
frequently sudden change of the material/structure properties and
accompanied by this a component weakening occur. In addition to
this, not all materials that are possible for a turbine/compressor
wheel, particularly not with inter-metal phases, can be
interconnected through fusion joining methods (beam
welding/brazing).
SUMMARY
[0007] The present invention therefore deals with the problem of
stating an improved or at least an alternative embodiment for a
rotor of the generic type which more preferably does not have the
disadvantages mentioned in the prior art.
[0008] According to the invention, this problem is solved through
the subjects of the independent claims. Advantageous embodiments
are the subject of the dependent claims.
[0009] The present invention is based on the general idea of
providing at least one porous, metal or ceramic adapter between the
shaft and the turbine wheel for connecting more preferably a
turbine wheel to a shaft of a rotor, which adapter is connected to
the turbine wheel and/or the shaft via an infiltration process.
Here, the mentioned turbine wheel obviously also stands exemplarily
for a compressor wheel that can be connected to the shaft in a
similar manner. The porous adapter can either be connected to the
shaft via infiltration, for example during a casting process of the
turbine wheel or by a casting-on process or sintered onto the shaft
or the turbine wheel in a sintering process in advance and
subsequently connected to the respective second component through
infiltration. Particularly in the case of a metal adapter,
connecting the adapter to the turbine wheel or to the shaft through
material joining, for example welding or brazing is also
conceivable, wherein a connection to the second component is
subsequently performed through infiltration. In general, the
invention has the following advantages: joining of a shaft and a
turbine wheel having totally different physical properties such as
for example a thermal expansion coefficient is possible, wherein
more preferably with conventional material joining, mechanically
non-stable phases can form in the interface. Here, the adapter
usually has a lower density than the turbine wheel or than the
shaft so that a centre of gravity of the rotor is advantageously
shifted in the direction of the compressor. Because of a suitable
material configuration a heat wear resistance can also be increased
in the region of radial shaft sealing rings. Of particular
advantage however is that materials that could not be combined in
the past can now also be joined together in a process-secure
manner, that is fastened to one another, wherein in the joining
region no sudden change of the material structure properties have
to be feared which could lead to an undesirable component weakening
in this region.
[0010] With an advantageous further development of the solution
according to the invention the adapter is designed as metal adapter
and materially connected to the shaft or the turbine wheel. This
would open up the optional possibility of replacing one of the two
infiltration processes, that is either the connecting of the
adapter to the shaft or to the turbine wheel through conventional
material connecting. Obviously, as an alternative to the material
connecting, sintering onto one of the two components can also be
chosen.
[0011] Further important features and advantages of the invention
are obtained from the subclaims, from the drawings and from the
corresponding figure description by means of the drawings.
[0012] It is to be understood that the features mentioned above and
still to be explained in the following cannot only be used in the
respective combination stated, but also in other combinations or
standing alone, without leaving the scope of the present
invention.
[0013] Preferred exemplary embodiments of the invention are shown
in the drawings and are explained in more detail in the following
description, wherein same reference characters refer to same or
similar or functionally same components.
BRIEF DESCRIPTION OF THE DRAWING
[0014] It shows, in each case schematically,
[0015] FIG. 1 a rotor according to the invention with an adapter
arranged between a shaft and a turbine/compressor wheel,
[0016] FIG. 2 a turbine wheel caulked to a shaft,
[0017] FIG. 3 a representation as in FIG. 2, however with another
embodiment,
[0018] FIG. 4 a rotor with a conical shaft for improved radial
alignment of a turbine/compressor wheel.
DETAILED DESCRIPTION
[0019] According to FIG. 1, a rotor 1 according to the invention
comprises a shaft 3 carrying a turbine wheel 2 for a charging
device which is not shown, more preferably for an exhaust gas
turbocharger. Here, the turbine wheel 2 can obviously also stand
analogously for a compressor wheel which is not designated in more
detail. According to the invention, for connecting the turbine
wheel 2 to the shaft 3 at least one porous metal or ceramic adapter
4 is now provided between said turbine wheel and the shaft 3, which
adapter is connected to the turbine wheel 2 and/or to the shaft 3
via an infiltration process. The adapter 4 according to the
invention can have an annular shape as is shown according to FIGS.
1a and 1b or a disc-like shape, as is drawn for example in FIG. 1c.
Compared with conventional connections of turbine wheels to
corresponding shafts a transition between the turbine wheel 2 and
the shaft 3 can be achieved with the rotor 1 according to the
invention without sudden change of material/structure properties
and thus without weak points that have been previously occurring
there. The adapter 4 can for example be connected in/to the turbine
wheel 2 during the casting process by means of infiltration and
subsequently to the shaft 3 via a casting-on process. Alternatively
it is also conceivable that the adapter 4 is sintered to the
turbine wheel 2 or to the shaft 3. In this case the adapter 4 for
example is connected to the turbine wheel 2 by means of a sintering
process while the connection to the shaft 3 is established in a
subsequent infiltration process.
[0020] In general it is also conceivable that the adapter 4 is
designed as metal adapter 4 and initially in a first connecting
step is materially connected to the shaft 3 or to the turbine wheel
2. Such a material connecting can be effected for example by means
of welding or brazing. In a subsequent manufacturing step the
adapter 4 is connected to the second component, i.e. for example to
the turbine wheel 2 or the shaft 3 by means of infiltration
process.
[0021] Considering FIG. 1b, it can be seen that the adapter 4 is
integrated, for example embedded in a back of the turbine wheel 2.
With the rotor 1 produced according to the invention it is more
preferably also possible to interconnect a turbine wheel 2 and a
shaft 3 with totally different physical properties, for example
thermal expansion coefficients, in a process-secure manner. Based
on the fact that the adapter 4 usually has a lower density than the
turbine wheel 2 or the shaft 3 a centre of gravity of the rotor 1
is advantageously also shifted in the direction of the compressor.
The rotor 1 according to the invention can also be configured for
optimum heat wear resistance of the rotor 1 in terms of material in
the region of radial shaft sealing rings. Through the porous
structure of the adapter 4 said adapter is infiltrated by a liquid
material of said shaft/turbine wheel during the connecting process,
as a result of which a particularly strong connection can be
achieved. Connecting the shaft 3 to the composite of turbine wheel
2 and adapter 4 can be presented in the following manner:
casting-on (infiltrating of a shaft material in a suitable device)
or through local melting-on of the shaft material blank under axial
pressure to the face end joining point. Obviously, the joining
process shown can also be performed in reverse order so that
initially casting-on or an infiltration of the adapter 4 to the
shaft 3 takes place and this composite formed of adapter 4 and
shaft 3 is subsequently used as insertion component in the casting
process of the turbine wheel 2 and is infiltrated by the material
of the turbine wheel 2.
[0022] Alternatively to the embodiment shown according to FIG. 1,
webs 6 radially standing away to the outside can be arranged on the
shaft 3 for connecting the turbine wheel 2 to the shaft 3, and/or
webs 6' radially standing away to the inside can be arranged on a
receiving opening 5 of the turbine wheel 2, which are plastically
deformed when the turbine wheel 2 is slid onto the shaft 3, as is
for example shown in the right sectional representation in FIG. 2.
The two sectional representations in this case are orientated
orthogonally to the sectional figure of the rotor 1 with respect to
a viewing plane. In the left sectional representation it can be
seen that the webs 6' are designed as longitudinal webs, wherein
circumferential webs are obviously also conceivable. The webs 6' in
this case have a smaller projection u, so that an outer diameter of
the shaft 3 is larger than an inner diameter of the receiving
opening 5. Here, caulking of the turbine wheel 2 with the shaft 3
results in a plastic deformation of the webs 6, 6', as a result of
which a positive and particularly sturdy connection can be
achieved. In the upper sectional representation in FIG. 2 a region
not yet caulked is marked with the reference character I, while the
already caulked region is shown with the reference character
II.
[0023] According to FIG. 2, the webs 6' are arranged as webs 6' on
the turbine wheel 2 standing away radially to the inside, wherein
according to FIG. 3 the webs 6 alternatively or additionally can
also be provided on the shaft 3 as webs 6 radially standing away to
the outside. In FIG. 3, too, the reference character II marks the
already caulked and the reference character I the region not yet
caulked.
[0024] Looking at FIGS. 2 and 3 once more it is clear that the
forming processes of the webs 6, 6' upon caulking of the turbine
wheel 2 to the shaft 3 is dependent on the hardness of the two
materials. Axially adjacent to the regions with the webs 6, 6' a
region 11 is provided at least on one end which has no webs 6 and
because of this makes possible a coaxial alignment of the
turbine/compressor wheel 2 on the shaft 3. A major advantage of
this type of connection is that for connecting no additional
operation such as screwing or welding is required. The webs 6, 6'
can have almost any shape, for example flutes, helicals, etc.
[0025] FIG. 4 shows a further alternative embodiment for connecting
a turbine wheel 2 to a shaft 3, wherein the shaft in this case has
a conically tapering region 7 with an outer thread 8 arranged on a
free end of the shaft 3. On the turbine wheel 2, a conical
receiving opening 9 designed complimentarily to the conical region
7 is provided, with an internal thread 10 following this, wherein
through the conical configuration of the conical region 7 or the
conical receiving opening 9 an exact radial alignment of the
turbine wheel 2 can be achieved. In this case the term turbine
wheel 2 obviously stands analogously for the connection of the
invention to a compressor wheel. Obviously it is also conceivable
that the outer thread 8 is located outside the turbine wheel 2,
wherein in this case a nut is screwed onto the outer thread 8,
which for improving the aerodynamic characteristics is covered with
a suitable cap which is not shown.
* * * * *