U.S. patent application number 12/902557 was filed with the patent office on 2011-05-19 for internal combustion engine comprising at least one camshaft.
Invention is credited to Thomas Flender, Michael Kreisig, Antonio Menonna, Falk Schneider.
Application Number | 20110114046 12/902557 |
Document ID | / |
Family ID | 43796686 |
Filed Date | 2011-05-19 |
United States Patent
Application |
20110114046 |
Kind Code |
A1 |
Flender; Thomas ; et
al. |
May 19, 2011 |
INTERNAL COMBUSTION ENGINE COMPRISING AT LEAST ONE CAMSHAFT
Abstract
An internal combustion engine, having at least one camshaft,
which is mounted in the radial direction via at least one bearing
block supplied with bearing fluid, wherein in the region of the
bearing block, two sealing rings are provided, which are axially
spaced apart from each other and which seal an annular chamber
supplied with bearing fluid and located between the camshaft and
the associated bearing block at least partially in the axial
direction.
Inventors: |
Flender; Thomas;
(Ehendinger, DE) ; Kreisig; Michael; (Stuttgart,
DE) ; Menonna; Antonio; (Ditzingen, DE) ;
Schneider; Falk; (Korntal-Munchingen, DE) |
Family ID: |
43796686 |
Appl. No.: |
12/902557 |
Filed: |
October 12, 2010 |
Current U.S.
Class: |
123/90.6 |
Current CPC
Class: |
F16C 2360/18 20130101;
F01L 2303/00 20200501; F01L 2001/0476 20130101; F01L 1/34 20130101;
F01L 1/3442 20130101; F01L 2810/02 20130101; F16C 33/74 20130101;
F01L 2001/34479 20130101; F01L 1/46 20130101 |
Class at
Publication: |
123/90.6 |
International
Class: |
F01L 1/047 20060101
F01L001/047 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 13, 2009 |
DE |
102009049217.8 |
Claims
1. An internal combustion engine, comprising; at least one
camshaft, which is mounted in the radial direction via at least one
bearing block supplied with bearing fluid, wherein in the region of
the bearing, two sealing rings are provided, which are axially
spaced apart from each other and which seal an annular chamber
supplied with bearing fluid and located between the camshaft and
the associated bearing block at least partially in the axial
direction.
2. The internal combustion engine according to claim 1, wherein at
least one bearing fluid feed channel extending in the bearing block
opens out in the annular chamber.
3. The internal combustion engine according to claim 1, wherein at
least one sealing ring is formed as the sealing ring, which is at
least one of closed and open in the circumferential direction.
4. The internal combustion engine according to claim 1, wherein at
least one sealing ring is formed from at least one of a plastic and
a metal.
5. The internal combustion engine according to claim 1, wherein at
least one sealing ring has at least one of a friction reducing
coating and a wear reducing coating.
6. The internal combustion engine according to claim 1, wherein at
least one sealing ring is formed in such a manner that a defined
leakage flow is possible.
7. The internal combustion engine according to claim 1, wherein a
groove is provided on at least one of the camshaft and the bearing
block, with which the associated sealing ring engages.
8. The internal combustion engine according to claim 1, wherein at
least one sealing ring is joined to at least one of the camshaft
and the bearing block.
9. The internal combustion engine according to claim 1, wherein at
least one sealing ring is formed at the same time as the axial
bearing.
10. The internal combustion engine according to claim 2, wherein at
least one sealing ring is formed as the sealing ring, which is at
least one of closed and open in the circumferential direction.
11. The internal combustion engine according to claim 4, wherein at
least one sealing ring is formed from at least one of a
polytetrafluoroethylene (PTFE) plastic and a cast metal
material.
12. The internal combustion engine according to claim 2, wherein at
least one sealing ring has at least one of a friction reducing
coating and a wear reducing coating.
13. The internal combustion engine according to claim 2, wherein at
least one sealing ring is formed in such a manner that a defined
leakage flow is possible.
14. The internal combustion engine according to claim 2, wherein a
groove is provided on at least one of the camshaft and the bearing
block, with which the associated sealing ring engages.
15. The internal combustion engine according to claim 2, wherein at
least one sealing ring is thermally joined on at least one of the
camshaft and the bearing block.
16. The internal combustion engine according to claim 2, wherein at
least one sealing ring is formed at the same time as the axial
bearing.
Description
[0001] The present invention relates to an internal combustion
engine comprising at least one camshaft which is mounted in the
radial direction in at least one bearing block supplied with a
bearing fluid.
[0002] Camshafts are usually mounted in internal combustion
engines, i.e., in particular in a cylinder crankcase (for overhead
camshafts, the mounting takes place in the cylinder head) of the
same, by means of bearing blocks supplied with bearing fluid. For
this, the bearing blocks comprise a bearing fluid feed channel
which transports bearing fluid, in particular bearing oil, and
which supplies an annular chamber located between the camshaft and
the associated bearing block with bearing fluid, i.e., for example
with oil, thereby mounting the camshaft in the radial direction. By
the rotational movement of the camshaft and by the pressure
difference within the annular chamber, the bearing fluid is
transported in the axial direction and discharges at an axial end
of the annular chamber into the cylinder crankcase/oil chamber of
the cylinder head. After discharging, it usually accumulates in a
bearing fluid pump and from there it is fed again by means of a
bearing fluid pump to the bearing block or annular chamber.
However, such a configuration has principally the disadvantage that
during the operation of the camshaft, a relatively large amount of
bearing fluid has to be pumped through the annular chamber, whereby
a significant capacity of the bearing fluid pump is required. At
the same time, a relatively high volume of bearing fluid has to be
provided. Due to the regulations which become increasingly
stricter, the automotive industry is more and more required to
reduce the energy consumption of internal combustion engines,
thereby reducing the emission.
[0003] The invention is concerned with the problem to offer an
improved embodiment of an internal combustion engine by means of
which in particular the energy consumption can be reduced.
[0004] This problem is solved according to the invention by the
subject matter of the independent claim 1. Advantageous embodiments
are subject matter of the dependent claims.
[0005] The invention is based on the general idea to at least
partially seal an annular chamber previously open in the axial
direction between a camshaft and a bearing block within an internal
combustion engine, thereby reducing a flow of bearing fluid through
the bearing. By reducing the bearing fluid flow, on the one hand, a
bearing fluid pump with a considerably reduced delivery rate can be
used and, on the other, the required amount of bearing fluid can be
reduced. Thus, due to the lower overall bearing fluid flow flowing
through the at least one bearing, the energy consumption of the
bearing fluid pump and thus the energy consumption of the whole
internal combustion engine can be reduced, whereby the same
consumes less fuel and thereby produces less emissions. For at
least partially sealing the annular chamber between the camshaft
and the associated bearing block, according to the invention, two
sealing rings are provided which are axially spaced apart from one
another.
[0006] In an advantageous development of the solution according to
the invention, at least one of the sealing rings is configured as a
sealing ring which is closed in circumferential direction or as an
open sealing ring. A closed sealing ring can be made, for example,
of plastic or metal and can be assembled during the fabrication of
the internal combustion engine by means of a particularly thermal
joining method or, in case of an embodiment made of plastic, by
means of an elastic elongation/compression. In contrast, rings
which are open in the circumferential direction, for example of the
kind of a VESPEL.RTM. ring, can advantageously be used during
repair and maintenance work. Such VESPEL.RTM. rings comprise teeth
in the circumferential direction, which teeth engage with one
another and which allows such a sealing ring to act in the axial
direction in a sealing manner, despite its embodiment which is open
in the circumferential direction. By configuring such sealing rings
as plastic parts, the same can be produced, for example, with a
cost-effective plastic injection molding method so that the
additional costs for implementing the invention are comparatively
small.
[0007] Suitably, at least one of the sealing rings comprises a
friction- and/or wear-reducing coating. Since sealing rings are
primarily intended to fulfill a sealing function, but, at the same
time, should not negatively influence the operation of the internal
combustion engine, such a friction-reducing coating is of
particular advantage because the same does not generate an
unfavorable influence on friction losses of the internal combustion
machine. In contrast, a wear-reducing coating increases the service
life of such sealing rings, whereby the quality of the internal
combustion engine and the reliability of the same can be
increased.
[0008] In a further advantageous embodiment of the solution
according to the invention, a groove is provided on the camshaft
and/or the bearing block with which groove an associated sealing
ring engages. Such a groove forms a guide for the associated
sealing ring so that the same can be fixed in place in particular
with respect to its axial direction. If an opposing groove is
provided on the bearing block as well as on the camshaft, a sealing
ring engaging therewith can absorb at the same time at least small
axial forces and serves in this case at least as support for an
axial bearing which is usually provided anyway.
[0009] Further important features and advantages arise from the
sub-claims, from the drawings, and from the associated description
of the figures based on the drawings.
[0010] It is to be understood that the above mentioned features and
the features yet to be explained hereinafter can be used not only
in the respectively mentioned combination but also in other
combinations or alone without departing from the scope of the
present invention.
[0011] Preferred exemplary embodiments of the invention are
illustrated in the drawings and are explained in the following
description in more detail, wherein identical reference numbers
refer to identical, or similar, or functionally identical
components.
[0012] In the figures, schematically,
[0013] FIG. 1 shows a sectional view through a camshaft in the
region of a bearing block comprising a bearing sealed according to
the invention,
[0014] FIG. 2 shows an illustration as in FIG. 1, but in a
different embodiment,
[0015] FIG. 3 shows an illustration as in FIG. 1, but in a further
embodiment,
[0016] FIGS. 4a,b each show sealing rings open in the
circumferential direction in the region of a joint.
[0017] According to the FIGS. 1 to 3, an internal combustion engine
1 according to the invention comprises a camshaft 2 which is
mounted in the radial direction via at least one bearing block 4
which is supplied with bearing fluid 3.
[0018] According to FIG. 1, the bearing block 4 is only partially
drawn. An annular chamber 5 supplied with bearing fluid 3, in
particular oil, extends between the camshaft 2 and the bearing
block 4, wherein the supply of this annular chamber 5 with bearing
fluid 3 is usually carried out via a bearing fluid feed channel 6
which runs in the bearing block 4 and opens out in the annular
chamber 5 (cf. FIGS. 2 and 3). Once the bearing fluid 3 is flowed
into the annular chamber 5 it is transported, due to a pressure
gradient and due to a rotational movement of the camshaft 2, in the
axial direction and discharges at an axial end of the bearing block
4 into an interior of the crankcase. In order to reduce a
comparatively high bearing fluid flow in connection with a high
delivery rate of a non-shown bearing fluid pump, the invention
proposes to provide in the region of the bearing block 4, two
sealing rings 7 and 7' which are axially spaced apart from one
another and which seal the annular chamber 5 supplied with bearing
fluid and located between the camshaft 2 and the associated bearing
block 4 at least partially in the axial direction. By the sealing
rings 7, 7', the bearing fluid or the oil, respectively, is thus
retained longer in the annular chamber 5, whereby, on the one hand,
the bearing fluid pump supplying the annular chamber 5 with bearing
fluid can be dimensioned smaller and in a more energy-saving manner
and, on the other, a total volume of a required amount of bearing
fluid can be reduced. Through the axial sealing of the annular
chamber 5, thus, a positive influence on the energy consumption of
the internal combustion engine and thus on the emission behavior of
the same can be achieved.
[0019] The sealing rings 7, 7' can be made, for example, of
plastic, in particular polytetrafluoroethylene, or metal, in
particular of a casting material. They can be configured, at the
same time, as sealing ring which is closed in the circumferential
direction or, as shown in the FIGS. 4a and 4b, as sealing rings 7,
7' which are open in the circumferential direction.
[0020] A joint 8 in the circumferential direction in the seals 7
shown according to the FIGS. 4a and 4b is formed like a labyrinth
which also helps to limit the bearing fluid flow in the axial
direction 9. Sealing rings 7, 7' made of plastic as well as of
metal can be produced in a cost-effective manner and, in addition,
can have, for example, a friction- and/or wear-reducing coating,
whereby friction losses within the internal combustion engine can
be reduced and thereby, also energy can be saved.
[0021] Generally, the term "sealing rings" is to be understood here
such that the same do not completely seal the annular chamber 5,
but allow an at least small leakage flow of bearing fluid 3 which
is exactly predefined with respect to its amount so that a
continuous flow of bearing fluid 3 through the annular chamber 5
and thus a cooling of said bearing is ensured.
[0022] Moreover, it can be provided that a groove 10 is provided on
the camshaft 2 and/or on the bearing block 4, with which groove the
associated sealing ring 7 engages. According to FIG. 1, only the
bearing block 4 is provided here with a recess-like groove 10,
wherein according to FIG. 2, on the camshaft 2 as well as on the
bearing block 4, adequate grooves 10 are provided. According to
FIG. 3, the grooves provided on the bearing block 4 are not
arranged opposite to each other, but interact with grooveless
opposite faces of the bearing block 4 or the camshaft 2,
respectively.
[0023] Closed sealing rings 7 can be inserted, for example, by an
elastic elongation or by a particularly thermal joining method into
the associated grooves 10 on the bearing block 4 or the camshaft 2,
and thereby can be reliably fixed therein. In particular in an
embodiment of opposing grooves 10 on the bearing block 4 as well as
on the camshaft 2, said grooves having a small axial extension can
guide the sealing ring 7 engaged therewith so that the same can
serve in this case at the same time as axial bearing for the
camshaft 2.
[0024] In general, with the sealing rings 7, 7' according to the
invention, a required capacity and thus a required energy
consumption of a bearing fluid pump can be considerably reduced,
whereby the energy consumption of the associated internal
combustion engine and its emission behavior can be positively
influenced. Grooves 10 which are to be provided, if necessary, as
well as the sealing rings 7, 7' themselves can be produced in a
cost-effective manner and, due to the significantly reduced energy
consumption, can be expected to be amortized quickly. Of course,
the sealing ring 7, 7' can also be provided between a bearing block
4 and an axially adjacent cam 11 as it is shown, for example,
according to FIG. 1.
* * * * *