U.S. patent application number 11/793873 was filed with the patent office on 2008-05-15 for blade mounting ring for a turbocharger on an internal combustion engine.
This patent application is currently assigned to Mahle Ventilrieb GmbH. Invention is credited to Roland Ruch, Lutz Steinert, Klaus Wintrich.
Application Number | 20080112815 11/793873 |
Document ID | / |
Family ID | 35355057 |
Filed Date | 2008-05-15 |
United States Patent
Application |
20080112815 |
Kind Code |
A1 |
Ruch; Roland ; et
al. |
May 15, 2008 |
Blade Mounting Ring For A Turbocharger On An Internal Combustion
Engine
Abstract
The invention relates to a blade mounting ring for a
turbocharger with variable turbine geometry and turbine blades
which may be adjusted in the blade mounting ring on an internal
combustion engine for a motor vehicle, comprising an austenitic
iron matrix alloy with a sulphur component to achieve a solid
lubrication effect on the bearing surfaces thereof with a material
embodiment suitable for high performance engines. The above is
achieved by means of a blade mounting ring with a proportion of 1
to 6 wt. % of an alloying element or several of the elements from
tungsten (W), cobalt (Co), niobium (Nb), rhenium (Re), molybdenum
(Mo), tantalum (Ta), vanadium (V), hafnium (Hf), yttrium (Y),
zirconium (Zr) or similar.
Inventors: |
Ruch; Roland; (Schopfheim,
DE) ; Steinert; Lutz; (Schopfheim, DE) ;
Wintrich; Klaus; (Schopfheim, DE) |
Correspondence
Address: |
COLLARD & ROE, P.C.
1077 NORTHERN BOULEVARD
ROSLYN
NY
11576
US
|
Assignee: |
Mahle Ventilrieb GmbH
|
Family ID: |
35355057 |
Appl. No.: |
11/793873 |
Filed: |
August 17, 2005 |
PCT Filed: |
August 17, 2005 |
PCT NO: |
PCT/DE05/01449 |
371 Date: |
June 21, 2007 |
Current U.S.
Class: |
416/244R |
Current CPC
Class: |
F05D 2220/40 20130101;
F02B 37/24 20130101; F01D 17/165 20130101; F01D 5/28 20130101 |
Class at
Publication: |
416/244.R |
International
Class: |
F04D 29/00 20060101
F04D029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 24, 2004 |
DE |
102004062564.6 |
Claims
1. A blade mounting ring of a turbocharger having a variable
turbine geometry and turbine blades adjustable in the blade
mounting ring on an internal combustion engine, made of an
austenitic iron matrix alloy having a sulfur content sufficient to
achieve a solid lubricant effect on its bearing surfaces, and
having an amount of 1 to 6 wt % of one or more of the alloy
elements tungsten (W), cobalt (Co), niobium (Nb), rhenium (Re),
molybdenum (Mo), tantalum (Ta), vanadium (V), hafnium (Hf), yttrium
(Y), zirconium (Zr) and/or comparable high-melting alloy
elements.
2. The blade mounting ring according to claim 1, by comprising the
following alloy composition with the amounts of individual alloy
elements, each given in percent by weight (wt %): C=0.4-0.6
Cr=18.27 Nb=1.4-1.8 Ni=12-22 S=0.2-0.5 Si=2.9-3.2 W=2.4-2.8
remainder=iron impurities and/or unspecified alloy elements up to
3.
3. The blade mounting ring according to claim 2, by comprising the
following alloy composition with amounts of the individual alloy
elements, each given in percent by weight (wt %): C=0.4-0.6
Cr=18.5-20.5 Nb=1.4-1.8 Ni=12.5-14 S=0.25-0.45 Si=2.9-3.15
W=2.4-2.8 remainder=iron impurities and/or unspecified alloy
elements up to 3.
4. The blade mounting ring according to claim 2, comprising the
following alloy composition with amounts of the individual alloy
elements, each given in percent by weight (wt %): C=0.4-0.6
Cr=24.5-26.5 Nb=1.4-1.8 Ni=19.5-21.5 S=0.25-0.45 Si=2.9-3.15
W=2.4-2.8 remainder=iron impurities and/or unspecified alloy
elements up to 3.
Description
[0001] The invention relates to a blade mounting ring on a
turbocharger having turbine blades adjustable in the blade mounting
ring according to the preamble of Patent claim 1.
[0002] With modern high-performance engines, extremely high demands
are made of the material on a blade mounting ring, such as that
used as component 38 in a turbocharger according to U.S. Pat. No.
4,643,640, for example, which is to remain functional for a long
time. Accordingly, a suitable material must have a sufficient creep
resistance, a high dimensional stability, which prevents thermal
deformation of the blade mounting ring even at high temperatures, a
high wear resistance and adequate oxidation resistance. If
deformation, creep or heavy oxidation occurs on a generic blade
mounting ring, it can result in locking of the turbine guide vanes,
i.e., the turbocharger cross section can no longer be adapted to
the driving performance of the engine by adjusting the guide
vanes.
[0003] In the past, mainly ferritic materials with a high chromium
and chromium carbide content have been used as the blade mounting
rings. For mounting rings that are subject to high thermal
stresses, austenitic materials containing chromium carbides are
used. Such an alloy contains the amounts given in weight percent as
follows, for example: C=0.4-0.7, Cr=18-21, Ni=12-14, S=0.2-0.4,
Si=1.8-2.2, the remainder being iron and nonspecific alloy
ingredients and/or impurities up to 3%. Such an alloy is referred
to below as alloy PL 23.
[0004] The present invention relates to the problem of designing
the material for generic blade mounting rings so they are reliable
in operation at extremely high temperatures. A high creep
resistance and a high strength at temperatures above 850.degree. C.
are desired in particular. At such high temperatures, the mobility
of the turbine blades in the generic blade mounting ring should be
absolutely certain.
[0005] This object is achieved by a generic blade mounting ring
having an alloy composition according to the characterizing feature
of claim 1.
[0006] Especially advantageous alloys for blade mounting rings are
the subject of the subordinate claims, whereby the alloys according
to claims 3 and 4 have proven to be an especially good
embodiment.
[0007] The invention is based on the general idea of fulfilling the
strict demands of creep resistance and strength of a blade mounting
ring material, in particular for high-performance engines by using
an austenitic iron material having a sulfur content that yields a
solid lubricant property, to which high-melting alloy elements are
added, and these alloy elements should amount to a percent by
weight between at least one percent by weight and up to six percent
by weight.
[0008] An increased creep resistance of the blade mounting ring
material that can be achieved according to this invention yields a
high dimensional stability of the blade mounting rings at elevated
temperatures. There is good lubrication on the contact surface
between the blade mounting ring and a turbine blade mounted
therein, in particular due to the effect of the solid lubricant,
which is attributable to the sulfur content in the bearing. With
the inventive use of materials, blocking of the turbine blades,
i.e., the guide vanes at high temperatures, is reliably
prevented.
[0009] The drawing shows some property diagrams for inventive blade
mounting ring materials. The curves labeled as A in the individual
diagrams indicate a material according to claim 3 and the curves
labeled as B indicate a material according to claim 4.
EXPLANATION OF THE INDIVIDUAL DIAGRAMS
[0010] FIGS. 1a, 1b
[0011] These diagrams show the creep behavior of the alloys A and B
under a step-wise load on a sample in increments of 2 MPa, a
holding time of 35 seconds and a measurement of creep rate in the
last five seconds of the holding time, namely in part a. for the
creep behavior at 700.degree. C. and in part b. for the creep
behavior at 900.degree. C.
[0012] FIG. 2
[0013] The elastic modulus E and the shear modulus G of the alloys
A and B are plotted as a function of temperature in this
diagram.
[0014] FIG. 3
[0015] This diagram shows the thermal expansion coefficients of
alloys A and B as a function of temperature.
[0016] FIG. 4
[0017] In this diagram, the hot hardness (in HV10) is plotted on
the ordinate as a function of the temperature for alloys A and
B.
[0018] FIG. 5
[0019] The hardness (in HB 2.5/187.5) of alloys A and B after
storage for two hours and air cooling as a function of temperature
is plotted on the ordinate.
[0020] FIG. 6
[0021] This figure is a table listing the following values for
alloys A and B at room temperature: .rho.=density, .lamda.=thermal
conductivity, R.sub.p02=strain limit, R.sub.m=tensile strength,
E=elastic modulus.
[0022] All the features depicted in the description and in the
following claims may be essential to the invention either
individually or in any combined form.
* * * * *