U.S. patent application number 13/202237 was filed with the patent office on 2012-01-19 for internal combustion engine comprising at least one camshaft.
Invention is credited to Thomas Flender, Michael Kreisig, Falk Schneider, Markus Walch.
Application Number | 20120012075 13/202237 |
Document ID | / |
Family ID | 42126086 |
Filed Date | 2012-01-19 |
United States Patent
Application |
20120012075 |
Kind Code |
A1 |
Schneider; Falk ; et
al. |
January 19, 2012 |
INTERNAL COMBUSTION ENGINE COMPRISING AT LEAST ONE CAMSHAFT
Abstract
An internal combustion engine, the engine having at least one
camshaft, the camshaft is interconnected to the internal combustion
engine through a plurality of rotating members, rotating members
include at least one roller element and a predetermined load limit.
The rotating members are configured individually along the camshaft
and are positioned according to an actual internal combustion
engine operating load value.
Inventors: |
Schneider; Falk;
(Korntal-Munchingen, DE) ; Flender; Thomas;
(Eberdingen, DE) ; Kreisig; Michael; (Stuttgart,
DE) ; Walch; Markus; (Bretten, DE) |
Family ID: |
42126086 |
Appl. No.: |
13/202237 |
Filed: |
February 10, 2010 |
PCT Filed: |
February 10, 2010 |
PCT NO: |
PCT/EP2010/051610 |
371 Date: |
September 23, 2011 |
Current U.S.
Class: |
123/90.1 ;
29/888.1 |
Current CPC
Class: |
F16C 19/56 20130101;
F16C 19/466 20130101; F16C 2360/18 20130101; Y10T 29/49293
20150115; F01L 2001/0476 20130101; F16C 41/008 20130101; F01L 1/047
20130101 |
Class at
Publication: |
123/90.1 ;
29/888.1 |
International
Class: |
F01L 1/46 20060101
F01L001/46; B21D 53/84 20060101 B21D053/84 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 19, 2009 |
DE |
102009009665.5 |
Claims
1. An internal combustion engine, comprising: at least one
camshaft, wherein the camshaft is mounted with a plurality of
roller bearings, the roller bearings include at least one roller
element and a predetermined roller bearing load limit, wherein the
bearings are configured individually along the camshaft and are
positioned according to an actual load value determined during the
operation of the internal combustion engine.
2. The internal combustion engine according to claim 1, wherein at
least two bearings have a different number of rolling elements.
3. The internal combustion engine according to claim 1, wherein at
least two bearings have rolling elements, which are different with
respect to their diameter.
4. The internal combustion engine according to claim 2, wherein the
rolling elements are needles.
5. The internal combustion engine according to claim 1, wherein the
camshaft and the at least one respective roller bearing includes at
least one corresponding marking element, which provides an
association between the roller bearing and assembly location of the
actual load value of the camshaft.
6. An internal combustion engine rotating assembly, comprising: at
least one camshaft, the camshaft having a plurality of different
operating loads; and at least two bearing elements configured on
the camshaft, the bearing elements having at least one bearing
capacity, each bearing capacity corresponding to the different
operating loads of the camshaft, wherein the load bearing elements
are configured about the camshaft adjacent at least one operating
load, and wherein a bearing element diameter at a first
predetermined position are different from the bearing elements at a
second predetermined position.
7. The rotating assembly according to claim 6, wherein a number of
roller elements configured about the camshaft at the first
predetermined position are different from a number of roller
elements configured at the second predetermined position.
8. The rotating assembly according to claim 6, wherein the rolling
elements are needles.
9. The rotating assembly according to claim 6, wherein roller
elements are roller bearings that include at least on marking, the
marking corresponds to a load marking on the camshaft, which
provides an association between the roller bearing and an assembly
location of the actual operating load value of the camshaft.
10. A method of reducing weight in an internal combustion engine,
comprising: selecting a first roller bearing with a plurality of
roller elements, each roller element having a first diameter;
selecting at least one additional roller bearing with a plurality
of roller elements, each roller element having a different diameter
from the first diameter; configuring the first roller bearing and
the at least one additional roller bearing at predetermined
positions on at least one camshaft; and implementing a configuring
of an internal combustion engine with the least one camshaft.
11. The method of claim 10, further comprising: determining an
actual operating load along the length of the camshaft; and
positioning at least one mark on the camshaft corresponding to the
operating load.
12. The method of claim 11, further comprising: determining a load
capacity of each respective roller bearing, wherein the first and
second roller bearings have different load capacities; comparing
the actual load with the roller bearing load capacity; positioning
at least one mark on at least one of the respective roller
bearings, the roller bearing mark represents the predetermined load
capacity and corresponds with the predetermined actual operating
load; and positioning the roller bearing on the at least one
camshaft, wherein the predetermined position corresponds to the
markings on the at least one camshaft and roller bearing.
Description
[0001] The present invention relates to an internal combustion
engine comprising at least one camshaft.
[0002] Camshafts in internal combustion engines are part of a
so-called valve train and are usually used to open and close intake
and exhaust valves according to a design-determined valve timing.
Such camshafts are usually mounted via so-called roller bearings
which consist of at least one ring with rolling elements rotatably
mounted therein. In order to be able to keep the variety of parts
as low as possible, up to now, usually, identical bearings are used
at all bearing positions of the camshaft which, however, is a
disadvantage with respect to weight and cost because in this case,
all bearings have to be designed for the maximally occurring
loads.
[0003] The present invention is concerned with the problem of
providing an improved embodiment for an internal combustion engine
with a camshaft, which embodiment can in particular be implemented
in a more cost-effective manner and with a lower weight.
[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 present invention is based on the general idea not to
use identical bearings at all bearing positions for mounting a
camshaft in an internal combustion engine, as it has been the case
up to now, but to embody the individual bearings individually and
to adapt them in particular with respect to their bearing capacity
to the loads actually occurring during the operation of the
internal combustion engine at the respective bearing positions. For
example, the loads for a bearing on a sprocket wheel of the
camshaft are comparatively high, whereas the loads in the central
region of the camshaft are often comparatively low. According to
the invention, a bearing which is capable of withstanding a higher
load or stress has now to be used in the region of the sprocket
wheel, whereas in the region subjected to a lower load, a bearing
can be used which, in comparison thereto, is lighter and in
particular more cost-effective. Due to the individual adaptation of
the individual bearings, in particular the total weight of all
bearings used can be reduced which has an advantageous effect on
the fuel consumption and therefore also on the CO.sub.2 emission of
the internal combustion engine. At the same time, the lighter
bearings can be produced in a more cost-effective manner, whereby a
reduction of the manufacturing costs can be achieved.
[0006] In an advantageous development of the solution according to
the invention, a color marking is to be attached in each case on
the camshaft and on the respective bearing, which color marking
allows or simplifies associating the respective bearing with an
assembly location on the camshaft. Since in contrast to the
previously used and identically structured bearings it is now
absolutely necessary for a problem-free operation of the camshaft
to assemble the respective bearings correctly, in particular in the
correct position, it must be reliably excluded during manufacturing
that, for example, a light bearing is assembled in the region of a
high load, for example in the region of a sprocket wheel, and wears
out there comparatively quickly due the high loads and consequently
has to be replaced quickly. The color markings on the camshaft and
on the associated bearings make it easier for the assembler to
correctly insert or correctly arrange the respective bearing so
that the latter, for example, merely has to assemble a bearing
marked in red at a position marked in red of the camshaft. By means
of such a color marking, the error rate when assembling the
bearings according to the invention can preferably be reduced to
zero.
[0007] Further important features and advantages of the invention
arise from the sub-claims, from the drawings, and from the
associated description of the figures based on the drawings.
[0008] 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 context of the
present invention.
[0009] 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.
[0010] In the figures, schematically:
[0011] FIG. 1 shows a camshaft comprising two different
bearings,
[0012] FIG. 2 shows a sectional view through different embodiments
of bearings according to the invention.
[0013] According to FIG. 1, a camshaft 1 for an internal combustion
engine, which otherwise is not shown here, has at least two
bearings 2 and 2' which, for example, can be configured as roller
bearings and by means of which the camshaft 1 is mounted in the
internal combustion engine. Also indicated are a cam 3 arranged on
the camshaft 1 and a sprocket wheel 4 arranged at the end of the
longitudinal side of the camshaft 1. According to the invention,
the individual bearings 2, 2' of which according to FIG. 1 only two
are illustrated, are configured individually and are adapted with
respect to their bearing capacity to the loads actually occurring
at the respective bearing position. For example, in the region of
the sprocket wheel 4, the load on the camshaft 1 is significantly
higher than for example in a central region so that according to
FIG. 1 and according to the invention, the bearing 2' is configured
to be stronger, higher loadable and also heavier than the bearing
2. Due to the individual and load-adapted configuration according
to the invention of the individual bearings 2, 2', it is no longer
necessary to design all bearings for a maximum load as it has
previously been the case when using identical bearings, but it is
possible, in particular at positions of low load, to use lighter
and/or more inexpensive bearings 2.
[0014] The individual bearings 2, 2' can differ for example in a
different number of rolling elements 5 as this is illustrated in
case of the three exemplary illustrated bearings 2, 2' in FIG. 2.
The individual bearings 2, 2' can also differ with respect to the
diameters of the individual rolling elements 5, wherein according
to FIG. 2, the rolling elements 5 of the bearing 2 drawn in the
middle have a significantly smaller diameter than for example the
rolling elements 5 of the bearing 2' drawn in the illustration on
the right. Moreover, depending on the expected load on the
individual bearings 2, 2'--as mentioned above--it is also possible
to provide a different number of rolling elements 5 so that for
example the bearing 2 in the left illustration of FIG. 2 has
significantly fewer rolling elements than the bearing 2 illustrated
in the middle of FIG. 2.
[0015] Since up to now, identical bearings were assembled on the
camshaft, it was not necessary to pay attention to a correctly
positioned arrangement of the individual bearings at an assembly
location on the camshaft 1. However, with the bearings 2, 2' which,
according to the invention, are configured individually, it is
required for a problem-free operation of the camshaft 1 to arrange
the different bearings 2, 2' according to their bearing capacity in
the correct position on the camshaft 1. For this purpose, color
markings 6, 6' which are attached according to the invention on the
camshaft 1 and on a respective bearing 2, 2' can be helpful and
make it is easier to associate the respective bearing 2, 2' with
the assembly location on the camshaft 1. Thus, for example, a
bearing marked in red can easily be associated with a red marked
assembly location on the camshaft 1 so that an error rate during
mounting or assembling the respective bearings 2, 2' can be at
least greatly reduced, preferably completely avoided.
[0016] With the bearings 2, 2' which, according to the invention,
are adapted individually and with respect to their bearing capacity
to the loads on the camshaft 1 it is not only possible to use
comparatively more cost-effective bearings 2, but it is in addition
also possible to reduce the total weight of the bearings 2, 2'
which has a positive effect on the fuel consumption and the
CO.sub.2 emission of the internal combustion engine.
* * * * *