U.S. patent application number 13/509636 was filed with the patent office on 2012-10-25 for axial bearing arrangement for a shaft of a turbocharger.
This patent application is currently assigned to CONTINENTAL AUTOMOTIVE GMBH. Invention is credited to Ralf Boening, Holger Faeth, Ralph Maurice Koempel.
Application Number | 20120269624 13/509636 |
Document ID | / |
Family ID | 43587656 |
Filed Date | 2012-10-25 |
United States Patent
Application |
20120269624 |
Kind Code |
A1 |
Boening; Ralf ; et
al. |
October 25, 2012 |
AXIAL BEARING ARRANGEMENT FOR A SHAFT OF A TURBOCHARGER
Abstract
A turbocharger has a turbocharger housing. At least one section
of the turbocharger housing is divided in the longitudinal
direction into at least two housing halves. A shaft is supported in
the turbocharger housing and at least one axial bearing arrangement
is provided for supporting the shaft in the axial direction.
Inventors: |
Boening; Ralf; (Reiffelbach,
DE) ; Faeth; Holger; (Fussgoenheim, DE) ;
Koempel; Ralph Maurice; (Mannheim, DE) |
Assignee: |
CONTINENTAL AUTOMOTIVE GMBH
HANNOVER
DE
|
Family ID: |
43587656 |
Appl. No.: |
13/509636 |
Filed: |
November 4, 2010 |
PCT Filed: |
November 4, 2010 |
PCT NO: |
PCT/EP10/66838 |
371 Date: |
May 14, 2012 |
Current U.S.
Class: |
415/229 |
Current CPC
Class: |
F02C 6/12 20130101; F04D
25/04 20130101; F05D 2220/40 20130101; F02C 7/06 20130101; F16C
17/047 20130101; F01D 25/168 20130101; F04D 29/0513 20130101; F04D
29/624 20130101; F16C 2360/24 20130101; F05D 2240/51 20130101; F04D
29/0563 20130101; F04D 29/4206 20130101; F16C 35/02 20130101; F05D
2240/52 20130101 |
Class at
Publication: |
415/229 |
International
Class: |
F01D 25/16 20060101
F01D025/16; F01D 1/06 20060101 F01D001/06 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 13, 2009 |
DE |
102009053102.5 |
Claims
1-10. (canceled)
11. A turbocharger (10), comprising: a turbocharger housing, said
turbocharger housing having at least one section divided in a
longitudinal direction to form at least two housing halves; a shaft
mounted in said turbocharger housing; and at least one axial
bearing arrangement disposed to support said shaft in an axial
direction.
12. The turbocharger according to claim 11, wherein said axial
bearing arrangement comprises at least one axial bearing, said
axial bearing being disposed on said shaft, on a bearing core, or
on a bearing collar on said shaft.
13. The turbocharger according to claim 12, wherein said
turbocharger housing is formed with a boundary portion on one side
or on both sides of said axial bearing, said boundary portion being
configured integrally with said turbocharger housing or being a
separate part fastened to said turbocharger housing.
14. The turbocharger according to claim 12, wherein said axial
bearing has a circumference with at least one projection or bracket
element for fastening said axial bearing to said turbocharger
housing, said axial bearing being fastened by said projection or
bracket element to said turbocharger housing.
15. The turbocharger according to claim 14, wherein said axial
bearing is fastened by said projection or bracket element to said
turbocharger housing by way of screw fixing and/or pinning.
16. The turbocharger according to claim 11, wherein said axial
bearing is fastened to an insert sleeve, to a bearing collar, to a
bearing core and/or to said turbocharger housing.
17. The turbocharger according to claim 16, wherein said axial
bearing is fastened by way of screw fixing and/or pinning.
18. The turbocharger according to claim 11, wherein said axial
bearing is disposed in a receptacle of said turbocharger housing,
and wherein at least one spring element is disposed to brace said
axial bearing in said receptacle.
19. The turbocharger according to claim 18, wherein said receptacle
is a recess or a hollow in said turbocharger housing.
20. The turbocharger according to claim 11, wherein said axial
bearing is disposed in a receptacle of said turbocharger
housing.
21. The turbocharger according to claim 20, wherein said receptacle
has a first receptacle section and said first receptacle section
forms with said axial bearing a transition fit or a clearance
fit.
22. The turbocharger according to claim 21, wherein said receptacle
has a second receptacle section, and wherein at least one disk
element and/or a spring element is disposed in said second
receptacle section in order to prevent unwanted axial movement of
said axial bearing.
23. The turbocharger according to claim 22, wherein said at least
one disk element is an oil barrier ring.
24. The turbocharger according to claim 22, wherein said receptacle
is formed as a stepped recess having one step forming said first
receptacle section and a second step forming said second receptacle
section.
25. The turbocharger according to claim 11, wherein said axial
bearing is selected from the group consisting of an axial bearing
disk, an axial sliding bearing, an axial magnetic bearing, and an
axial rolling bearing.
Description
[0001] Axial bearing arrangement for a shaft of a turbocharger
[0002] The invention relates to an axial bearing arrangement for a
shaft in a turbocharger, the housing or a section of the housing of
the turbocharger preferably being divided in a longitudinal
direction into at least two housing halves.
[0003] In general, a turbocharger consists of an exhaust gas
turbine in an exhaust gas mass flow, which turbine is connected via
a shaft to a compressor in the intake duct. In this case the
turbine wheel of the turbine is arranged in a turbine housing and
the compressor wheel of the compressor in a compressor housing. The
shaft is in turn mounted in a bearing housing. In operation, the
turbine wheel is driven by the exhaust gas mass flow and in turn
drives the compressor wheel. In this case the compressor compresses
the aspirated air and conducts it to the internal combustion
engine. Normally the shaft is supported in the bearing housing by
means of a radial bearing arrangement. As a result of fluid flows
impinging on the turbine wheel and the compressor wheel, strong
axial forces can arise. In general, such axial forces cannot be
appropriately absorbed by the radial bearings. For this reason at
least one or two additional axial bearings are provided in order to
absorb these axial forces appropriately.
[0004] Furthermore, the design of turbochargers up to now has
provided individual housings fastened to one another in series and
sealed with respect to one another. A new form of turbocharger
housing now provides that the turbocharger housing is divided in a
longitudinal direction and not, as hitherto, transversely to its
longitudinal axis, that is, in a transverse direction. This new
turbocharger housing is the subject matter of a further patent
application.
[0005] Accordingly, it is the object of the present invention to
make available an appropriate axial bearing arrangement for a shaft
of a turbocharger, in particular of a turbocharger having a
turbocharger housing divided in a longitudinal direction.
[0006] This object is achieved by a turbocharger having a
turbocharger housing with an axial bearing arrangement having the
features of claim 1.
[0007] According to the invention, therefore, a turbocharger is
made available with a turbocharger housing wherein at least one
section of the turbocharger housing is configured to be divided or
subdivided in a longitudinal direction into at least two housing
halves, wherein a shaft is mounted in the turbocharger housing and
wherein at least one axial bearing arrangement is provided in order
to support the shaft in the axial direction.
[0008] In this case the turbocharger has the advantage that the
axial bearing arrangement can be fitted to the rotor assembly and
the rotor assembly with the axial bearing arrangement can then be
placed complete in the housing halves of the turbocharger housing
divided in a longitudinal direction.
[0009] Advantageous configurations and developments of the
invention are apparent from the dependent claims and from the
description, with reference to the drawings.
[0010] The invention is explained in more detail below with
reference to the exemplary embodiments represented in the schematic
figures of the drawings, in which:
[0011] FIG. 1 is a view of a housing half of a turbocharger which
is configured to be divided in a longitudinal direction into two
housing halves, the shaft being provided in the turbocharger
housing with a radial bearing arrangement and an axial bearing
arrangement according to a first embodiment of the invention;
[0012] FIG. 2 is a sectional view of the turbocharger according to
FIG. 1;
[0013] FIG. 3 is a sectional view through a turbocharger housing
having an axial bearing arrangement according to a further variant
of the first embodiment of the invention;
[0014] FIG. 4 is a sectional view through a turbocharger housing
having an axial bearing arrangement according to a second
embodiment of the invention;
[0015] FIG. 5 is a sectional view through a turbocharger housing
divided in a longitudinal direction with an axial bearing
arrangement according to a third embodiment of the invention;
[0016] FIG. 6 is a sectional view through a turbocharger housing
divided in a longitudinal direction with an axial bearing
arrangement according to a fourth embodiment of the invention,
and
[0017] FIG. 7 is a sectional view through a turbocharger housing
divided in a longitudinal direction with an axial bearing
arrangement according to a fifth embodiment of the invention.
[0018] In all the figures like or functionally like elements and
devices--unless otherwise stated--are denoted by the same reference
numerals. Furthermore, the representation of the turbocharger in
the following figures is purely schematic, not to scale and highly
simplified.
[0019] FIG. 1 shows a sectional view through a turbocharger 10
having a turbocharger housing 12 which is configured to be divided
in a longitudinal direction into, for example, at least two housing
halves 14. FIG. 1 shows a housing half 14 from the seal side. The
housing half 14 has a recess 15 or groove in which a sealing
arrangement can be received for fastening the two housing halves in
a sealed manner. In this case the recess 15 and the path of the
recess 15, in which a sealing arrangement is provided in order to
seal the housing halves 14, are purely exemplary and the invention
is not limited to this example. Moreover, the sealing of the two
housing halves is the subject matter of a separate patent
application.
[0020] In the example in FIG. 1, the turbocharger housing 12
comprises a bearing housing 18, a turbine housing 20 and a
compressor housing 22, all three housings being, for example,
combined to form one housing and being configured to be divided
along the longitudinal direction into at least two housing halves
14. In principle, the whole turbocharger housing 12, as in FIG. 1,
or at least a section of the turbocharger housing 12, may be
configured to be divided in a longitudinal direction into at least
two housing halves 14.
[0021] In the present case the turbocharger housing 12 is
configured to be divided in a longitudinal direction, for example
in a horizontal plane, the longitudinal axis 24 of the turbocharger
housing 12 lying in this case in the horizontal plane. In
principle, however, the turbocharger housing 12 may be configured
to be divided into at least two housing halves 14 in every plane in
the longitudinal direction. Furthermore, the longitudinal axis 24
does not need to lie in this parting plane or, for example, to
intersect said parting plane, although it may do so.
[0022] In the present example, the turbocharger housing 12 may
optionally be configured to be additionally at least partially
coolable and/or heatable. More precisely, in the example shown in
FIG. 1 the turbocharger housing 12 has in the region of the turbine
housing 20 and of the bearing housing 18 an additional fluid jacket
26 or temperature regulating jacket into which a fluid, for example
water, can be conducted in order to regulate the temperature of, or
to cool and/or heat this region of the turbocharger housing 12,
depending on the function and application.
[0023] The housing half 14 shown in FIG. 1 is fastened and sealed
to the other, corresponding housing half (not shown). For this
purpose, at least one or a plurality of bores 28, for example, are
provided in order to screw and/or pin the two housing halves 14 to
one another. Moreover, any other form of fastening which is
suitable for connecting the two housing halves 14 to one another
and making possible or itself providing a seal between the two
housing halves 14, may be provided. In this case, a bead seal, an
O-ring seal and/or an elastomeric seal, for example, may be
provided as a sealing device for sealing the two housing halves 14.
The bead seal, or one of the other seals, is placed in a suitable
recess 15 in one or both of the housing halves 14, while the other
housing-half surfaces which are not sealed are, for example, in
direct contact with one another.
[0024] In FIG. 1, a shaft 30 on which a turbine wheel 32 and a
compressor wheel 34 are provided is mounted in the bearing housing
section 18 of the turbocharger housing 12. In this case the turbine
wheel 32 is arranged in the turbine housing section 20 and the
compressor wheel 34 in the compressor housing section 22 of the
turbocharger housing 12. In the present example, the shaft 30 has a
radial bearing arrangement 36 and an axial bearing arrangement 38,
according to the first embodiment of the invention.
[0025] For the turbocharger 10, an axial bearing arrangement 38
comprising at least one or a plurality of axial bearings is used in
order to absorb, for example, the axial thrust and to position
axially the rotor assembly, or the turbine and compressor wheels
32, 34, in such a way as to achieve both relatively high efficiency
through narrow flow gaps and to prevent damage. In a turbocharger
housing 12 divided in a longitudinal direction, as shown in FIG. 1,
an axial bearing can no longer be installed axially since the rotor
disk 32, 34 or rotor is inserted radially and axial access no
longer exists. Hitherto, with a turbocharger housing divided in a
transverse direction, an axial bearing was firmly screw-fastened
axially in a closed bearing housing prior to assembly. The rotor
assembly was then mounted afterwards with the bearing
arrangement.
[0026] According to the first embodiment of the invention, as shown
in FIG. 1 and the following FIG. 2, the axial bearing arrangement
38 is now also mounted on the rotor assembly, and the bearing
surface is provided and machined with the housing half.
[0027] In this case the axial bearing arrangement 38 according to
the invention comprises at least one axial bearing 40, for example
in the form of an axial bearing disk. As shown in FIG. 1, this
axial bearing 40 is fastened to the shaft 30 of the rotor assembly.
In order to be fastened to the shaft 30, the axial bearing
arrangement 38 may be cramped, screwed, pressed and/or shrunk
thereon, to mention only a few examples of fastening possibilities.
This applies to all embodiments of the invention. In this case the
axial bearing 40 may be bounded on one side by a step of the shaft,
and optionally on the other side additionally by a bush element 42
or a sleeve. In this case the bush element 42 additionally has on
its outer side at least one sealing device 44 for sealing the
bearing housing section 18 with respect to the compressor housing
section 22. As the sealing device 44 in this case, two piston ring
seals in corresponding grooves on the outside of the bush element
42 may, for example, be provided.
[0028] In addition, in the example shown in FIG. 1, the shaft 30 is
mounted by means of a radial bearing arrangement 36. In this case,
the radial bearing arrangement 36 has on its outer side a sleeve
element 46 consisting, for example, of metal, e.g. steel, or
including same, and has a collar section 48 at each end. In this
case at least one or both collar sections 48 of the sleeve element
46 are, for example, configured to be resilient, in order to be
tensioned between two stops or receptacles 50, or in this case
projections of the turbocharger housing 12, and to tension the
bearing arrangement provided in the sleeve element 46 in the axial
direction. Equally, one or both collar sections 48 may be
configured to be non-resilient or stiff, and may be placed between
the two stops 50. In this case one or both collar sections 48 may
optionally be additionally fastened, for example by means of
screws, to the associated receptacle 50. Optionally, at least one
resiliently-acting or stiff collar section may also be additionally
screw-fastened and/or pinned to the respective associated
receptacle 50. In this case one or both collar sections 48 are, for
example, connected integrally or as separate parts to the sleeve
element 46. In this case the separate collar section 48 may
optionally be additionally fastened to the sleeve element 46, for
example locked and/or screwed thereto, after the sleeve element 46
has been inserted in the bore.
[0029] In this case, one or both collar sections 48 of the sleeve
element 46 may also optionally project additionally from the oil
chamber, both on the turbine side, as shown in FIG. 1, and on the
compressor side (not shown), and take over further functions, for
example that of a heat shield. One or both collar sections 48 may,
however, remain within the oil chamber, like the collar section 48
on the compressor side in FIG. 1. The sleeve element 46 may now
itself be configured, for example, as a radial sliding bearing
arrangement (not shown) and form two sliding bearing sections.
Alternatively, the sleeve element 46, as shown in the embodiment in
FIG. 1, may also receive a sleeve 54 which includes the two sliding
bearing sections 52. Instead of the sleeve 54, however, two radial
bearings may, for example, be also provided as sliding bearings,
which radial bearings optionally are additionally arranged in the
sleeve element 46 and spaced from one another by means of a spacer
sleeve (not shown). Alternatively, the sleeve element 46 may also
be configured on its inner side as a spacer sleeve with a stop for
each sliding bearing (not shown). Furthermore, a layer 56
consisting of at least one or a plurality of plies of an elastic,
heat-resistant or temperature-resistant material may optionally be
provided additionally on the inner and/or outer side of the sleeve
element 46, as shown in FIG. 1. In this case the material consists,
for example, of a polymer, an elastomer and/or a hard rubber.
However, the invention is not limited to these materials. In
principle, any other suitable, heat-resistant or
temperature-resistant, elastic material may be used.
[0030] As is shown in FIG. 1, the sleeve 54 is fitted to the shaft
30, the shaft 30 having, for example, a step with a stop for the
sleeve 54. The axial bearing arrangement 38, which forms a stop for
the sleeve 54 or the radial bearing arrangement 36 in the axial
direction, is provided at the other end of the sleeve 54.
Optionally, a sheet metal oil barrier 58, for example, may
additionally be arranged on the axial bearing arrangement 38 or the
axial bearing disk 40, the axial bearing disk 40 optionally having
additionally a receptacle 60 for the sheet metal oil barrier 58.
The shaft 30 can easily be placed, together with the sleeve 54, the
layer 56 made of an elastic material or material combinations, and
the sleeve element 46 with the two collar sections 48, in the
housing halves 14 of the longitudinally divided turbocharger
housing 12.
[0031] FIG. 2 shows in addition a sectional view through the
turbocharger housing 12, both housing halves 14, 16 being
represented. In this case the seal between the two housing halves
14, 16 is also indicated in highly simplified form.
[0032] FIG. 3 further shows a sectional side view through a
turbocharger housing 12 with an axial bearing arrangement 38
according to a further variant of the first embodiment of the
invention. In this case a portion of the bearing housing section 18
of both housing halves 14, 16 is shown in a sectional view. The
shaft 30 is mounted in the housing 18 by means of a radial bearing
arrangement 36 consisting, for example, of two sliding bearings 62
between which, for example, a spacer sleeve 64 is additionally
arranged. An axial bearing arrangement 38 comprising at least one
axial bearing 40, for example in the form of an axial bearing disk,
is further provided. The axial bearing disk 40 is in this case
fastened to the shaft 30 of the rotor assembly, being, for example,
cramped, pressed or shrunk thereon, to mention only a few examples
of possibilities of fastening the axial bearing arrangement 38 to
the rotor or to the shaft 30. As shown in FIG. 3, the axial bearing
40 may be arranged in a hollow or recess of the turbocharger
housing 12, the recess having on one or both sides a boundary
portion 66 for the axial bearing arrangement 38. The boundary
portion 66 or projection may be formed integrally or may be
fastened to the turbocharger housing 12 as a separate part. In this
case the boundary portion 66 additionally opposes unwanted axial
movement of the axial bearing 40, and serves here as an axial
boundary portion.
[0033] Furthermore, a bush element 42, which may additionally have
sealing elements on its outer side, may optionally be additionally
provided for sealing the bearing housing section with respect to
the rotor housing section (not shown). A disk element 79, which
serves, for example, to spin off lubricant from the shaft 30, may,
for example, be additionally provided adjacent to the bush element
42.
[0034] The first embodiment according to the invention, in which
the rotor assembly includes an axial bearing arrangement 38 mounted
on the shaft 30, has the advantage that it is no longer necessary
to fasten an axial bearing arrangement 38 separately in the housing
12. The assembled rotor assembly can be placed directly therein. In
addition, the recess or boundary portion 66 on one or both sides of
the axial bearing 40 opposes unwanted axial movement of the axial
bearing 40. However, the axial bearing 40 does not need to be
placed in a recess or to have one or two lateral boundary portions
66, since the axial bearing 40 is itself fastened firmly to the
shaft 30.
[0035] FIG. 4 shows in addition a sectional view through both
housing halves 14, 16 of a longitudinally divided turbocharger
housing 12 having an axial bearing arrangement 38 according to a
second embodiment of the invention. In this case the housing halves
14, 16 are shown from the front. The axial bearing arrangement 38
also comprises at least one axial bearing 40, for example in the
form of an axial bearing disk. The axial bearing 40 has at least
one or two bracket elements 68 or projections with which the axial
bearing 40 is screwed firmly to a housing half 16. In this case it
is not necessary additionally to fasten the axial bearing
arrangement 38 firmly to the shaft 30, for example by cramping or
shrinking, etc., as shown in FIGS. 1, 2 and 3. The axial bearing
arrangement 38 may have play between its opening 70 and the
external circumference of the shaft 30.
[0036] The advantage of the second embodiment according to the
invention, in which the axial bearing arrangement 38 is fixed
radially with bracket elements 68, is that the axial bearing
arrangement 38 can already be fitted to the rotor assembly and then
fastened, for example screwed and/or pinned, in the housing half 16
perpendicularly to the main or longitudinal axis 24. In this case
one has very easy, unobstructed access with a screwdriver to the
screwing location.
[0037] FIG. 5 shows a sectional side view through a turbocharger
housing 12 with an axial bearing arrangement 38 according to a
third embodiment of the invention. In this case a shaft 30
supported radially by means of two radial sliding bearings 62 is
represented, it being possible for the radial sliding bearings
optionally to be arranged additionally in an insert sleeve 54, as
shown in FIG. 5. In the example in FIG. 5 a shaft step is, for
example, provided on one or both sides of the radial bearing
arrangement 36, on which shaft step an additional bearing collar 72
serving to provide the bearing surfaces for the axial bearing is
arranged. In this case the bearing collar 72 is configured, for
example, as a rotary part or a rotationally symmetrical part. The
bearing collar 72 has in turn on its outer side a receptacle 74,
for example in the form of a step or a recess (not shown), for the
axial bearing arrangement 38. In this case the axial bearing
arrangement 38 comprises at least one axial bearing 40, for example
in the form of an axial bearing disk. Play is provided between the
axial bearing 40 and the bearing collar 72, since the bearing
collar 72 rotates with the shaft 30 while the axial bearing 40 is
fixed. For this purpose the axial bearing 40 may be fastened, for
example by means of one or more screws 76 and/or pins (not shown),
to the insert sleeve 54 and/or to the housing 12. The bearing
collar 72, by contrast, is fastened in such a way that it rotates
with the shaft 30. For this purpose the bearing collar 72 is, for
example, clamped to the shaft 30 by means of a shaft nut, in which
case a clearance fit or transition fit may be provided between the
shaft 30 and the bearing collar 72. However, the bearing collar 72
may also be fastened to the shaft 30 in any other way.
[0038] The axial bearing arrangement 38 may be fastened, for
example, to a separately installed insert sleeve 54, as shown in
FIG. 5, for example by means of the fastening methods and fastening
means described previously. Optionally, a further disk element 79,
which can be used to spin off lubricant such as oil from the shaft
30, may be additionally provided adjacent to the bearing collar 72.
Because the axial bearing arrangement can be fastened to the
housing 12 and/or to the insert sleeve 54, an additional step or
boundary portion which additionally opposes axial movement of the
axial bearing arrangement, as in FIG. 3, can be dispensed with in
this case. In principle, however, such a boundary portion may be
provided on one or both sides of the axial bearing 40, depending on
function and application.
[0039] The third embodiment according to the invention, in which
the axial bearing arrangement 38 is arranged on a bearing collar 72
or bearing core or is screwed to an insert sleeve 54, has the
advantage that the axial bearing arrangement 38 can be assembled
outside the housing halves of the turbocharger housing 12 and then
placed therein together with the rotor.
[0040] FIG. 6 further shows a sectional side view through a
turbocharger housing 12 and its two housing halves 14, 16, with an
axial bearing arrangement 38 according to a fourth embodiment of
the invention. In this embodiment the axial bearing arrangement 38
may be arranged, for example, directly on the rotor or the shaft 30
(not shown) or, as shown in FIG. 6, on a bearing collar 72. In this
case the axial bearing arrangement 38 likewise comprises at least
one axial bearing 40, for example in the form of an axial bearing
disk. The axial bearing 40 may in this case be provided on the
bearing block 72 as described earlier, for example in FIG. 5, the
bearing collar 72 serving to provide the bearing surfaces for the
axial bearing. In this case the axial bearing 40 is fixed rigidly
or via at least one spring element 78, while the bearing collar 72
rotates with the shaft 30. Depending on the function and
application, the bearing collar 72 may also be omitted. In that
case the shaft 30 provides the bearing surface for the axial
bearing 40 (not shown).
[0041] In order to fix the axial bearing arrangement 38, at least
one spring element 78, with which the axial bearing arrangement 38
is braced axially in the turbocharger housing 12, is used according
to the fourth embodiment according to the invention. In this case
the axial bearing arrangement 38 is fitted in a receptacle 60 in
the form, for example, of a recess or hollow in the bearing housing
section 18 and braced in the receptacle 60 by means of the spring
element 78, so that unwanted movement of the axial bearing 40 in
the axial direction is opposed. In this case the axial bearing
arrangement 38 is pressed against an axial surface of the
receptacle 60 by the at least one spring element 78. Optionally, at
least one oil barrier ring 79 which is also tensioned on the shaft
30 may additionally be provided, as shown in FIG. 6, the oil
barrier ring 79 spinning off the oil or lubricant. Likewise, a
spring element (not shown), which is arranged, for example, on the
shaft 30 in the receptacle 60, may optionally be provided
additionally in order to fix the axial bearing 40 additionally in
the axial direction.
[0042] The fourth embodiment according to the invention has the
advantage that the spring element 78 and the receptacle or groove
allow the axial bearing arrangement 38 to be fitted onto the rotor.
In this case screw-fixing processes are omitted.
[0043] FIG. 7 shows a sectional side view through a turbocharger
housing 12 with an axial bearing arrangement 38 according to a
fifth embodiment of the invention. The axial bearing arrangement 38
also comprises at least one axial bearing 40, for example in the
form of an axial bearing disk. In this case the axial bearing 40,
as described previously, may be arranged, for example, directly on
the shaft 30 (not shown) or, for example, on a bearing collar 72,
as shown in FIG. 7, and may form, for example, a clearance fit with
the shaft 30 or with the bearing collar 72. In other words, the
axial bearing 40 is fixed while the bearing collar 72 rotates with
the shaft 30. In this case the axial bearing 40 may be simply
fitted into an associated receptacle 60 or, optionally, may
additionally be clamped or fastened therein. In order to fasten the
axial bearing 40, it may optionally be fixed, for example in the
housing 12, on its outer circumference with at least one sealing
device 44, for example an O-ring or a piston ring seal, etc.
[0044] In the fifth embodiment of the invention, the receptacle 60
for receiving an axial bearing 40 in the turbocharger housing 12 is
configured in the form of a recess or a groove, the receptacle 60
having a first receptacle section 80 in which the axial bearing
disk 40 is received, and the first receptacle section 80 being
configured in such a way that, or having a boundary portion such
that, it opposes unwanted axial movement of the axial bearing 40.
In this case the first receptacle section 80 forms with the axial
bearing 40 a clearance fit or a transition fit, for example. This
has the advantage that the axial bearing 40 can be fitted very
easily into the first receptacle section 80 of the receptacle 60
and at the same time unwanted axial movement of the axial bearing
40 can be prevented, since the boundary portion 66 of the
receptacle section 80 prevents unwanted axial movement of the axial
bearing 40.
[0045] A second receptacle section 82 of the receptacle 60 is
configured in such a way that at least one disk element 79, for
example an oil barrier ring and/or a spring element, can be
arranged in the receptacle 60, for example on the shaft 30, in
order to oppose unwanted axial movement of the bearing collar 72 or
of the axial bearing 40. In this case the receptacle 60 is
configured, for example, with a step, as shown in FIG. 7, in order
to form the first and second receptacle sections 80, 82. In this
case the second receptacle section 82 forms, for example, an oil
chamber or lubricant chamber in which an oil barrier ring 79, by
means of which oil or lubricant can be spun off, may be arranged.
In this case the oil barrier ring 79 forms an axial bearing surface
for the axial bearing 40.
[0046] The fifth embodiment according to the invention has the
advantage that the groove or the first receptacle section 80 allows
the axial bearing arrangement 38 to be fitted to the rotor. In this
case additional fastening processes, such as screw fixing
processes, are likewise omitted.
[0047] The invention is not restricted to the aforedescribed
embodiments. In particular, the aforedescribed embodiments,
especially individual features of the different embodiments, may be
combined with one another.
[0048] The invention is also not restricted to the radial bearing
arrangements 36 as described hereinbefore with reference to the
figures. In principle, any other radial bearing arrangement may be
used to support the shaft 30 of the turbocharger. The core of this
invention is the axial bearing arrangement 38. In this case, in
addition to the axial bearing disk 40 shown in the figures, any
other axial bearing 40 can be used, for example an axial
contactless bearing such as an axial magnetic bearing, an axial
rolling bearing and/or an axial sliding bearing, etc., to mention
only a few further examples of axial bearings 40.
* * * * *