U.S. patent application number 12/863422 was filed with the patent office on 2010-12-23 for method for producing integrally bladed rotors.
This patent application is currently assigned to MTU AERO ENGINES GMBH. Invention is credited to Erwin Bayer, Martin Bussmann, Albin Platz.
Application Number | 20100319194 12/863422 |
Document ID | / |
Family ID | 40673994 |
Filed Date | 2010-12-23 |
United States Patent
Application |
20100319194 |
Kind Code |
A1 |
Bayer; Erwin ; et
al. |
December 23, 2010 |
METHOD FOR PRODUCING INTEGRALLY BLADED ROTORS
Abstract
A method for producing integrally bladed rotors comprises the
following steps: a) defining and providing a blade profile of a
blade to be manufactured with a pre-contour and a theoretical
contour; b) producing at least two sectional planes of the blade
profile, which sectional planes run vertically to a threading axis
of the blade profile and of the blade to be manufactured; c)
determining a point of rotation per sectional plane to produce an
interval between the pre-contour and the theoretical contour that
is approximately the same circumferentially, which points of
rotation are located on a connecting line running parallel to the
threading axis; and d) providing a base rotor body and
electrochemically working the base rotor body in order to produce a
raw blade with the blade pre-contour by movement of a hollow
electrode into the base rotor body, the electrode movement
including advancing motion along the connecting line superposed by
rotation at the points of rotation, and which hollow electrode has
an inner contour adapted to the pre-contour of the raw blade at
least in an end area that is moved into the base rotor body.
Inventors: |
Bayer; Erwin; (Dachau,
DE) ; Bussmann; Martin; (Schwabhausen, DE) ;
Platz; Albin; (Ried-Baindlkirch, DE) |
Correspondence
Address: |
HOWISON & ARNOTT, L.L.P
P.O. BOX 741715
DALLAS
TX
75374-1715
US
|
Assignee: |
MTU AERO ENGINES GMBH
Munich
DE
|
Family ID: |
40673994 |
Appl. No.: |
12/863422 |
Filed: |
December 20, 2008 |
PCT Filed: |
December 20, 2008 |
PCT NO: |
PCT/DE2008/002143 |
371 Date: |
July 16, 2010 |
Current U.S.
Class: |
29/889.6 |
Current CPC
Class: |
B23H 9/10 20130101; Y10T
29/49332 20150115 |
Class at
Publication: |
29/889.6 |
International
Class: |
B21D 53/78 20060101
B21D053/78 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 17, 2008 |
DE |
10 2008 004 776.7 |
Claims
1-11. (canceled)
12. A method for producing integrally bladed rotors, the method
comprising the following steps: a) defining and providing a blade
profile of a blade to be manufactured with a pre-contour and a
theoretical contour; b) producing at least two sectional planes of
the blade profile, which sectional planes run vertically to a
threading axis of the blade profile and of the blade to be
manufactured; c) determining a point of rotation per sectional
plane to produce an interval between the pre-contour and the
theoretical contour that is approximately the same
circumferentially, which points of rotation are located on a
connecting line running parallel to the threading axis; and d)
providing a base rotor body and electrochemically working the base
rotor body in order to produce a raw blade with the blade
pre-contour by movement of a hollow electrode into the base rotor
body, the electrode movement including advancing motion along the
connecting line superposed by rotation at the points of rotation,
and which hollow electrode has an inner contour adapted to the
pre-contour of the raw blade at least in an end area that is moved
into the base rotor body.
13. A method in accordance with claim 12, wherein a plurality of
hollow electrodes is moved simultaneously or successively into the
base rotor body.
14. A method in accordance with claim 13, wherein prior to moving
each of the plurality of hollow electrodes, a respective connecting
line is determined along which the advancing motion of the
respective hollow electrode takes place.
15. A method in accordance with claim 12, wherein the points of
rotation are arranged off-center relative to the blade profile.
16. A method in accordance with claim 12, wherein during the step
of providing a base rotor body and electrochemically working the
base rotor body, a pre-allocation of intermediate spaces between
two adjacent raw blades takes place.
17. A method in accordance with claim 12, wherein the hollow
electrode is constructed in an electrically insulating manner
except for an end area that is moved into the base rotor body.
18. A method in accordance with claim 12, further comprising: e)
electrochemically working the raw blade having the blade
pre-contour to produce a blade having fluidic surfaces
corresponding to the theoretical contour.
19. A method in accordance with claim 18, wherein the
electrochemical working of the raw blade having the blade
pre-contour is performed using a precise electrochemical removal
process (PECM).
20. A method in accordance with claim 19, wherein during the
electrochemical working of the raw blade having the blade
pre-contour, at least one of an inner contour and an outer contour
of at least one electrode is adapted to the theoretical contour of
the blade.
21. A method in accordance with claim 19, wherein during the
electrochemical working of the raw blade having the blade
pre-contour, the electrode executes oscillating movements.
22. A method for integrally forming a raw blade having a
pre-contour on a base rotor body for which a blade profile
including a threading axis, a raw blade pre-contour and a blade
theoretical contour have been defined, the method comprising the
steps: providing a base rotor body for which a blade profile
including a threading axis, a raw-blade pre-contour and a blade
theoretical contour have been defined; providing a hollow electrode
having an inner contour configured to the raw blade pre-contour at
least in an end area; defining a plurality of sectional planes of
the blade profile, the sectional planes being spaced apart along
the threading axis; determining a point of rotation for each
sectional plane, each point of rotation constituting a point at
which the hollow electrode is to be rotated to produce a
substantially uniform overmeasure between the respective
pre-contour and the respective theoretical contour of the sectional
plane, the points of rotation defining a connecting line; and
electrochemically working the base rotor body while moving the end
area of the hollow electrode into the base rotor body with an
advancing motion along the connecting line superposed by rotation
at the points of rotation; whereby a raw blade with the blade
pre-contour is produced, the pre-contour having a substantially
uniform overmeasure with respect to the theoretical contour.
23. A method in accordance with claim 22, wherein the points of
rotation are arranged off-center relative to the blade profile.
24. A method in accordance with claim 22, wherein the hollow
electrode is constructed in an electrically insulating manner
except for the end area.
25. A method for integrally forming a blade on a base rotor body
for which a blade profile including a threading axis, a raw blade
pre-contour and a blade theoretical contour have been defined, the
method comprising the steps: providing a base rotor body for which
a blade profile including a threading axis, a raw-blade pre-contour
and a blade theoretical contour have been defined; providing a
hollow electrode having an inner contour configured to the raw
blade pre-contour at least in an end area; defining a plurality of
sectional planes of the blade profile, the sectional planes being
spaced apart along the threading axis; determining a point of
rotation for each sectional plane, each point of rotation
constituting a point at which the hollow electrode is to be rotated
to produce a substantially uniform overmeasure between the
respective pre-contour and the respective theoretical contour of
the sectional plane, the points of rotation defining a connecting
line; electrochemically working the base rotor body while moving
the end area of the hollow electrode into the base rotor body with
an advancing motion along the connecting line between each point of
rotation; rotating the electrode at each point of rotation while
continuing to electrochemically work the base rotor body and
advancing along the connecting line until a raw blade with the
blade pre-contour is produced, the pre-contour having a
substantially uniform overmeasure with respect to the theoretical
contour; and electrochemically working the raw blade having the
blade pre-contour using an electrode wherein at least one of an
inner contour and an outer contour is configured to the theoretical
contour of the blade; whereby a blade having fluidic surfaces
substantially corresponding to the theoretical contour is
integrally produced on the base rotor body.
26. A method in accordance with claim 25, wherein the electrode
used to produce the raw blade having the pre-contour and the
electrode used to produce the blade have the theoretical contour
are the same electrode.
27. A method in accordance with claim 25, wherein the electrode
used to produce the raw blade having the pre-contour and the
electrode used to produce the blade have the theoretical contour
are different electrodes.
28. A method in accordance with claim 25, wherein during the
electrochemical working of the raw blade having the blade
pre-contour, the electrode executes oscillating movements.
29. A method in accordance with claim 25, wherein the points of
rotation are arranged off-center relative to the blade profile.
30. A method in accordance with claim 25, wherein the hollow
electrode is constructed in an electrically insulating manner
except for the end area.
31. A method in accordance with claim 25, wherein the
electrochemical working of the raw blade having the blade
pre-contour is performed using a precise electrochemical removal
process (PECM).
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. National Phase application
submitted under 35 U.S.C. .sctn.371 of Patent Cooperation Treaty
application serial no. PCT/DE2008/002143, filed 20 Dec. 2008, and
entitled METHOD FOR PRODUCING INTEGRALLY BLADE-MOUNTED ROTORS,
which application claims priority to German patent application
serial no. 10 2008 004 776.7, filed 17 Jan. 2008, and entitled
VERFAHREN ZUR HERSTELLUNG VON INTEGRAL BESCHAUFELTEN ROTOREN.
[0002] Patent Cooperation Treaty application serial no.
PCT/DE2008/002143, published as WO 2009/089816, and German patent
application serial no. 10 2008 004 776.7, are incorporated herein
by reference.
TECHNICAL FIELD
[0003] The present invention relates to a process for producing
integrally bladed rotors, especially rotors of a gas turbine by an
electrochemical process. The invention furthermore relates to an
integrally bladed rotor produced with the named process.
BACKGROUND
[0004] Slender three-dimensional geometries of metallic structural
components such as, for example, blisk blades are worked out of a
solid material as a rule, at which time the so-called
pre-allocation of the individual blades, i.e. the production of
blade pre-profiles takes place by milling processes. In addition,
the production of blade pre-profiles by water-jet cutting or
eroding is known. In addition, it is possible to pre-allocate the
intermediate blade space in the case of blisk blades by a straight
or curved slot by electrochemical removal processes such as the
so-called ECM (Electro Chemical Machining) or by grinding. In the
cited ECM process the surface of the workpiece is worked as a rule
with an electrode, during which a removal of material on the
workpiece takes place by electrochemical reaction of the workpiece
with the electrolyte located between the workpiece and the
electrode. The electrode is connected as cathode to a direct
current source. The electrode then moves at a given speed toward
the structural component poled as anode. The width of the working
slot between the electrode and the structural component is of
considerable significance. In customary ECM processes the work is
carried out with intervals from the element to the workpiece that
can be in a range of 1 to 2 mm. In order to produce finer
structures and forms the interval can be reduced to magnitudes in a
range of 10 to 50 .mu.m and above. However, the successful use of a
poled ECM process (PECM) requires in many areas of use a uniform
overmeasure of the blade and/or blade pre-profile to be worked.
Thus, for example, an electrochemically produced pre-contour of a
blade pan of a gas turbine, in particular of a blisk blade,
previously had an overmeasure between ca. 1 and ca. 3 mm,
conditioned by the process. In order to produce a necessary uniform
overmeasure in these instances the non-uniform overmeasure was
previously worked by milling. However, such processes can be used
only in a very limited manner, in particular in the working of
slender structural components such as, e.g., blade pans, since
there is a danger of damage here such as, for example, a
deformation of the structural parts. In addition, such a procedure
for the production of blade pre-profiles is relatively
time-consuming and therewith cost-intensive due to the plurality of
process steps.
SUMMARY
[0005] The present disclosure therefore addresses the problem of
making available a generic process for the production of integrally
bladed rotors, in particular rotors of a gas turbine, which
facilitates a relatively rapid and precise production of raw blades
with approximately the same overmeasure.
[0006] The present disclosure furthermore addresses_the problem of
making available an integrally bladed rotor of the initially cited
type that can be produced relatively rapidly and precisely.
[0007] These problems are addressed by a process in accordance with
the features disclosed and claimed herein as well as by an
integrally bladed rotor in accordance with the disclosure and
claims.
[0008] Advantageous embodiments of the invention are described in
the particular subclaims.
[0009] A process in accordance with one aspect of the invention for
producing integrally bladed rotors, in particular rotors of a gas
turbine, comprises the following steps: [0010] a) The defining of
and making available a blade profile of a blade to be manufactured
with a pre-contour and theoretical contour; [0011] b) The
production of at least two sectional planes of the blade profile,
which sectional planes run vertically to a threading axis of the
blade profile and of the blade to be produced; [0012] c) The
determining of a point of rotation per sectional plane in such a
manner that the interval between the pre-contour and the
theoretical contour is approximately the same circumferentially,
which points of rotation are located on a connecting line running
parallel to the threading axis; [0013] d) Making available a base
rotor body and the electrochemical working of the base rotor body
in order to produce a raw blade with a blade pre-contour by a
lowering of a hollow electrode into the base rotor body, during
which an advance movement of the hollow electrode, that is
superposed by rotation, takes place along the connection line
determined in process step c), and during which the hollow
electrode has an inner contour adapted to the pre-contour of the
raw blade at least in an end area that is lowered onto the base
rotor body.
[0014] The process in accordance with the invention facilitates_the
production of blade pre-profiles for integrally bladed rotors with
a uniform circumferential overmeasure in all cross sections by a
simple lowering movement with a hollow electrode which movement
compensates the blade twist by a rotation, which hollow electrode
encloses the overmeasure blade in the interior. In addition, it is
possible that a pre-allocation of intermediate spaces between two
adjacent raw blades takes place at the same time in process step
d). The process in accordance with the invention ensures that the
overmeasure contour results in each step in an almost uniform
overmeasure on the convex side and concave side of the blade
although the lateral has a three-dimensional swung form.
Furthermore, the process in accordance with the invention ensures
the use of a simple electrode contour for lowering the intermediate
spaces of the blade in the case of integrally bladed rotors.
[0015] In an advantageous embodiment of the process in accordance
with the invention a plurality of hollow electrodes is moved
simultaneously or successively into the base rotor body. Prior to a
lowering of the plurality of hollow electrodes a determination of
the connecting line for the determining of the advance movement of
each hollow electrode can take place. This ensures that each raw
blade produced has an optimized overmeasure.
[0016] In a further advantageous embodiment of the process in
accordance with the invention the points of rotation are arranged
off-center relative to the blade profile. In addition, the points
of rotation are located off-center relative to the contour of the
hollow electrode. This process has proven to be especially
advantageous for the rapid and precise production of raw
blades.
[0017] In a further advantageous embodiment of the process of the
invention the hollow electrode is constructed in an electrically
insulating manner up to an end area that is lowered onto the base
rotor body. This ensures that no undesired removal events occur on
the raw blade by the inner contour of the electrode.
[0018] In further advantageous embodiments of the process of the
invention, after the production of the raw blades according to the
process steps a) to d) an electrochemical working of the raw blades
takes place for making available fluidic surfaces in accordance
with the theoretical contour of the blades to be produced. The
electrochemical working can take place here by a precise
electrochemical removal process (PECM). For the rest, it is also
conceivable that the production of the raw blades takes place by a
PECM process. Even in the precise electrochemical removal the
inner- and/or outer contour of at least one electrode used to this
end can be adapted to the theoretical contour of the blades. In
addition, the precision of the removal procedure can be raised
during the precise electrochemical removal by an oscillating of the
electrode during lowering. The cited measures make it possible to
efficiently produce integrally bladed rotors such as blisks and
blings.
[0019] A gas turbine rotor integrally bladed in accordance with the
invention is produced according to a process described above. The
rotor integrally bladed in accordance with the invention can be
rapidly and precisely produced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] An exemplary embodiment of the process in accordance with
the invention is described in detail in the following with
reference made to the figures.
[0021] FIG. 1 shows a schematic lateral view of several raw blades
of an integrally bladed rotor which blades are produced with the
process in accordance with the invention; and
[0022] FIG. 2 shows a schematic top view onto the integrally bladed
rotor according to FIG. 1.
DETAILED DESCRIPTION
[0023] FIG. 1 shows a schematic lateral view of several raw blades
12 produced with the process for the production of integrally
bladed rotors 10. In the exemplary embodiment shown the rotor is a
so-called blisk. The raw blades 12 as well as the rotor disk 18
connected to them are worked out of a base disk body. Raw blades 12
have a blade pre-contour with a uniform overmeasure so that they
can be readily further processed. The further processing takes
place, for example, by a PECM process with which fluidic surfaces
can be produced according to the theoretical contour of the final
blades to be produced.
[0024] FIG. 2 shows a schematic top view onto integrally bladed
rotor 10 according to FIG. 1. Here, two points of rotation 14, 16
are sketched in by way of example. Points of rotation 14, 16 each
correspond to a sectional plane through the blade profile, namely,
vertically to a threading axis of the blade profile. Points of
rotation 14, 16 are determined in such a manner per sectional plane
that the interval between a pre-contour and a theoretical contour
of the blades to be produced is circumferentially approximately the
same, and the points of rotation 14, 16 are located on a connecting
line running parallel to the threading axis. The advance movement
of a hollow electrode (not shown), that is additionally superposed
by a rotation about the particular points of rotation 14, 16, takes
place along the determined connecting line. The hollow electrode is
constructed in such a manner here at least in an end area that is
lowered onto the base rotor body that this hollow electrode has an
inner contour that is adapted to the pre-contour of the raw blade.
Furthermore, it can be recognized that points of rotation 14, 16
are arranged off-center relative to the blade profile of the raw
blades. In addition, it is clear that a pre-allocation of the
intermediate spaces 20 between adjacent raw blades 12 takes place
by the lowering of the hollow electrode in the direction of the
base rotor body. The integrally bladed rotor 10 produced can
consist of alloys based on nickel, cobalt or titanium.
* * * * *