U.S. patent application number 12/800444 was filed with the patent office on 2010-09-16 for housing for a radical compressor.
Invention is credited to Hedwig Schick, Jan Velthuis, Stephan Wild.
Application Number | 20100232955 12/800444 |
Document ID | / |
Family ID | 40350265 |
Filed Date | 2010-09-16 |
United States Patent
Application |
20100232955 |
Kind Code |
A1 |
Schick; Hedwig ; et
al. |
September 16, 2010 |
Housing for a radical compressor
Abstract
A housing for a radial compressor is comprised of at least two
housing parts manufactured of plastic material for receiving a
compressor wheel and for forming a spiral-shaped compressor
passage, wherein into the housing between compressor wheel
receptacle and compressor passage an annular space is introduced
that annularly surrounds the compressor wheel and into which a
stabilization element is introduced.
Inventors: |
Schick; Hedwig; (Tamm,
DE) ; Wild; Stephan; (Neuenburg, DE) ;
Velthuis; Jan; (Pitzling, DE) |
Correspondence
Address: |
KLAUS J. BACH
4407 TWIN OAKS DRIVE
MURRYSVILLE
PA
15668
US
|
Family ID: |
40350265 |
Appl. No.: |
12/800444 |
Filed: |
May 14, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/EP2008/063146 |
Oct 1, 2008 |
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12800444 |
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Current U.S.
Class: |
415/204 |
Current CPC
Class: |
B29C 66/114 20130101;
F05D 2300/43 20130101; B29C 66/12841 20130101; B29C 66/73921
20130101; F04D 29/023 20130101; F05D 2220/40 20130101; B29L
2031/7496 20130101; B29C 66/545 20130101; B29C 65/08 20130101; B29K
2081/04 20130101; B29C 66/1282 20130101; B29C 66/71 20130101; B29K
2101/12 20130101; F01D 21/045 20130101; B29K 2081/04 20130101; B29C
66/71 20130101; F04D 29/441 20130101; B29C 66/112 20130101; F04D
29/4206 20130101; B29C 66/1142 20130101; B29C 66/543 20130101 |
Class at
Publication: |
415/204 |
International
Class: |
F01D 25/24 20060101
F01D025/24 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 20, 2007 |
DE |
10 2007 055 615.4 |
Claims
1. A housing for a radial compressor, comprised of at least two
housing parts (2, 3, 4) manufactured of plastic material for
receiving a compressor wheel (7) and for forming a spiral-shaped
compressor passage (8), wherein in the housing (1) between a
compressor wheel receptacle (5) and the spiral-shaped compressor
passage (8) a hollow space is introduced, the hollow space being an
annular space (10) that surrounds the compressor wheel (7) with at
least one stabilization element disposed in the annular space
(10).
2. The housing according to claim 1, wherein the annular space (10)
is delimited by two housing parts (3, 4).
3. The housing according to claim 2, wherein the housing parts that
delimit the annular space (10) are embodied as inwardly positioned
bearing shell (4) forming the compressor wheel receptacle (5) and
as compressor front part (3).
4. The housing according to claim 3, wherein the bearing shell (4),
on the side facing away from the compressor wheel receptacle (5),
forms an annular groove (16) that forms a part of the annular space
(10).
5. The housing according to claim 1, wherein the housing is of a
three-part configuration and comprises the compressor front part
(3), a compressor rear wall (2), and the inwardly positioned
bearing shell (4).
6. The housing according to claim 5, wherein the compressor front
part (3) has a contact area (15) with the bearing shell (4) and a
further contact area (14) with the compressor rear wall (2).
7. The housing according to claim 1, wherein the contact areas (14,
15) between the housing parts (2, 3, 4) are arranged at a spacing
to the spiral-shaped compressor passage (8).
8. The housing according to claim 7, wherein the contact areas (14,
15) are positioned adjacent to the intake opening (6) of the
housing (1).
9. The housing according to claim 1, wherein the housing parts (2,
3, 4) are welded to one another, in particular by ultrasonic
welding.
10. The housing according to claim 1, wherein a stabilization
element in the annular space (10) is embodied as fill material.
11. The housing according to claim 10, wherein the fill material is
comprised of plastic material.
12. The housing according to claim 1, wherein the stabilization
element in the annular space (10) is embodied as a separate
component, for example, as a fill hose (11).
13. The housing according to claim 1, wherein the housing parts (2,
3, 4) are manufactured of thermoplastic material and in particular
producible by injection molding.
14. The housing according to claim 13, wherein the housing parts
are comprised of polyphenylene sulfide (PPS).
Description
[0001] This is a cip application of pending international patent
application PCT/EP2008/063146 filed Oct. 1, 2008 and claiming the
priority of German patent application 10 2007 055 615.4 filed Nov.
20, 2007.
TECHNICAL FIELD
[0002] The invention concerns a housing for a radial compressor
comprising two housing parts consisting of plastic and having a
spiral-shaped compressor passage and a compressor wheel disposed in
the housing.
PRIOR ART
[0003] In DE 103 14 209 B3 a radial compressor as a component of an
exhaust gas turbocharger is described that is comprised of two
shell-shaped housing parts that are injection-molded from thermoset
material. This material has a high density so that, in comparison
to other conventional charger housings of metal, no weight-related
advantage results. DE 103 14 209 B3 attempts to counteract this in
that into one of the housing parts chamber-like recesses are
introduced that are separated from one another by partitions and
that essentially extend concentrically to an air intake axis.
[0004] The housing parts are glued together which however requires
a relatively high manufacturing expenditure. Thermoset resin as a
material is furthermore characterized by a relatively high
brittleness and high water absorption as well as a relatively
minimal dimensional stability at high temperatures. Moreover, there
is great acoustic radiation and the manufacturing costs are also
relatively expensive.
[0005] In case of radial compressors moreover a satisfactory
operating safety must be taken into consideration. Because of the
high wheel speeds of turbochargers there is the risk that upon
damage of the compressor wheel metal fragments of the wheel will
penetrate the housing of the compressor and will damage components
in the engine compartment of the internal combustion engine.
SUMMARY OF THE INVENTION
[0006] The invention has the object to produce a lightweight
dimensionally precise housing for a radial compressor with
satisfactory seal-tightness and high heat resistance from plastic
material wherein, in case of damage of the compressor wheel, the
risk of metal fragments flying about is to be reduced.
[0007] This object is solved according to the invention in that an
annular hollow space is provided in the housing which extends
around the compressor wheel and at least one stabilizing element is
disposed in the annular space.
[0008] The housing according to the invention for a radial
compressor is comprised of at least two housing parts manufactured
of plastic material which, on the one hand, are designed for
receiving a compressor wheel and between which, on the other hand,
a spiral-shaped compressor passage is formed. Into the housing
between a compressor receptacle that serves for receiving and
supporting the compressor wheel and the spiral-shaped compressor
passage a circumferentially extending annular space is formed that
annularly surrounds the compressor wheel. In this annular space at
least one stabilization element is introduced.
[0009] The housing parts manufactured of plastic material,
comprised in particular of thermoplastic material and produced by
the injection-molding process, for example, of polyphenylene
sulfide (PPS), fulfill together with the annular space in which at
least one stabilization element is introduced also high safety
requirements, in particular in case of fracture of the compressor
wheel. The annular space is located at the radial outer side of the
compressor wheel so that broken-off wheel fragments that are thrown
off tangentially outwardly as a result of the high rotary speed of
the compressor wheel will impact on the annular space and the
stabilizing element arranged therein. The walls of the annular
space ensure already an effective reduction of the broken-off
tangentially thrown wheel parts; in addition, there is the
stabilizing element that is received in the annular space that, on
the one hand, counteracts deformation of the walls of the annular
space and improves as a whole the stability of the housing and, on
the other hand, upon impact of a broken-off wheel fragment,
provides effective damping. The stabilization element therefore has
a double function: on the one hand, the annular space and thus the
entire housing is supported or reinforced; on the other hand, in
case of an accident, the protection from thrown-off wheel fragments
is improved.
[0010] In axial direction the annular space advantageously extends
at least about the axis length of the compressor wheel wherein
optionally also an extension substantially about the length of one
of the housing parts that delimits the annular space may be
considered.
[0011] As a stabilization element a separate component is to be
considered that is inserted into the annular space. For example,
the stabilization element is embodied as a fill hose, for example,
comprised of aramide fiber or the like, that is inserted into the
annular space upon assembly of the housing. For the purpose of
facilitating assembly of the housing, an annular groove can be
introduced into one of components delimiting the annular space and
forms part of the annular space and provides a receptacle for the
stabilization element already before assembly of the two housing
parts.
[0012] In the radial direction, the annular space has an extension
that enables insertion of the stabilization element. Relative to
the wall thickness of the delimiting wall the radial extension is
preferably a multiple of the wall thickness, for example, three
times to five times the wall thickness. Moreover, it may be
expedient to match the radial extension of the annular space,
viewed about the circumference, to the shape of the spiral-shaped
compressor passage. Since the compressor passage in the
circumferential direction has a variable diameter, a greater radial
extension for the annular space is available in sections of smaller
diameter of the compressor passage than in sections with greater
diameter.
[0013] The manufacture of the compressor housing of thermoplastic
material, in particular PPS, has the advantage of easy manufacture
as well as good recyclability. In the manufacture by injection
molding, a lost core technology is not required; manufacture is
realized by injection molding by means of molds of a simple
configuration that can be opened and closed. A further advantage
resides in the manufacture of complex geometries of the housing,
for example, a spiral passage with several undercuts. Finally,
thermoplastic materials can be produced with high dimensional
precision so that post-processing can be dispensed with or the need
for it is limited. Moreover, the thermoplastic material is
heat-resistant, pressure-tight and has excellent sound-insulating
properties at minimal weight.
[0014] A further advantage resides in the possibility of
configuring housing parts with constant wall thickness so that
material accumulations are avoided and the risk of cavity formation
is reduced.
[0015] The housing parts can be welded together in particular by
way of ultrasonic welding. In order to be able to position the
ultrasonic probe (sonotrode) in a simple way at the required
welding seam, advantageously the contact area between the housing
parts to be welded is adjacent to the axial end face of the
housing, in particular adjacent to the intake side. Moreover, the
contact areas between the housing parts are preferably located at a
spacing to the spiral-shaped compressor passage; they are thus
removed from the critical spiral area so that the air guiding
action on the inner side of the spiral is not impaired by an
undesirable burr caused by welding in the wall.
[0016] According to a further advantageous embodiment, the housing
as a whole is comprised of three housing parts including a
compressor front part, a compressor rear wall, and an inwardly
positioned bearing shell. The compressor front part and compressor
rear wall form the outer housing parts between which the bearing
shell is positioned that serves for receiving the compressor wheel.
The annular space is provided preferably between the bearing shell
and the compressor front part.
[0017] Further advantages and expedient embodiments are disclosed
in the further claims, the figure descriptions, and the
drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The only FIGURE shows a section of a housing for a radial
compressor comprised of three individual housing parts of
thermoplastic material that are welded together by ultrasonic
welding wherein between an inwardly positioned bearing shell and a
compressor front part an annular space is formed that surrounds the
compressor wheel receptacle.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0019] The illustrated housing 1 for a radial compressor is a
component of an exhaust gas turbocharger of an internal combustion
engine in which the exhaust gases of an internal combustion engine
drive a turbine wheel that is fixedly connected to compressor wheel
that is rotatably supported in the housing 1. By rotation of the
compressor wheel combustion air is sucked into the intake manifold
and compressed to an increased charge pressure at which the
combustion air is supplied to the cylinders of the internal
combustion engine.
[0020] The housing 1 is of a three-part configuration and comprises
a compressor rear wall 2, a compressor front part 3, and an
inwardly positioned bearing shell 4 that delimits a compressor
wheel receptacle 5 for receiving and supporting the compressor
wheel that in the embodiment is referenced by reference numeral 7
and is illustrated only schematically by a dotted line. The
combustion air is axially supplied to the compressor wheel 7 by an
intake socket 6 that is formed in the compressor front part 3. The
compressed combustion air is guided radially through diffuser 9
into a spiral-shaped compressor passage 8 that is delimited by the
compressor front part 3 and compressor rear wall 2 and that opens
into an outlet socket by means of which the compressed combustion
air is supplied finally to the cylinders of the internal combustion
engine.
[0021] Between the compressor front part 3 and the bearing shell 4
a circumferentially extending annular space 10 is formed that
radially surrounds the compressor wheel receptacle 5 and is
separated fluid-tightly from the compressor wheel receptacle 5 by
means of the wall of the bearing shell 4. The annular space 10 has
substantially the same axial extension as the bearing shell 4 and
thus also the compressor wheel receptacle 5. A separate component
in the form of a fill hose 11 is inserted into the annular space 10
that has the function of a stabilization element and, in addition
to providing reinforcement of the housing 1, also takes on a safety
function in case of an accident in that broken-off wheel fragments
of the compressor wheel 7 that are tangentially thrown outwardly
are caught by the stabilization element 11.
[0022] The housing parts 2, 3, 4 are comprised of thermoplastic
material and are joined by way of ultrasonic welding. This is done
such that a sonotrode is placed onto the contact areas 14, between
the compressor rear wall 2, and the compressor front part 3, or 15,
between the bearing shell 4 and the compressor front part 3, in
order to perform the process of ultrasonic welding. The first
contact area 14 between compressor rear wall 2 and compressor front
part 3 is located in the radial outer area, neighboring the end
face that forms the intake side of the housing. The contact area
15, on the other hand, is positioned radially inwardly displaced
between the bearing shell 4 and the compressor front part 3
immediately neighboring the compressor wheel receptacle 5 but also
on the side of the housing that is facing the intake side.
[0023] The bearing shell 4 is formed in such a way that in the area
of the annular space 10 in the bearing shell 4 an annular groove 16
is formed that is supplemented to the annular space 10 by the
compressor front part 3 to be positioned thereon. The annular
groove 16 has the advantage that already before positioning the
compressor front part 3 a receptacle for insertion of the
stabilization element is provided; this is in particular
advantageous in the variant embodied as a separate component in
accordance with FIG. 1 because in this case the stabilization
element embodied as a separate component is received safely in the
annular groove 16 before positioning the compressor front part.
* * * * *