U.S. patent application number 14/133124 was filed with the patent office on 2014-06-19 for camshaft.
This patent application is currently assigned to Mahie International GmbH. The applicant listed for this patent is Mahie International GmbH. Invention is credited to Thomas Flender, Dautel Gerlingen, Antonio Menonna, Stefan Steichele.
Application Number | 20140165935 14/133124 |
Document ID | / |
Family ID | 49626829 |
Filed Date | 2014-06-19 |
United States Patent
Application |
20140165935 |
Kind Code |
A1 |
Gerlingen; Dautel ; et
al. |
June 19, 2014 |
CAMSHAFT
Abstract
A camshaft of an internal combustion engine may include at least
one function device connected therewith via a shaft-hub connection.
The function device may include at least two different function
elements each operable for different function
Inventors: |
Gerlingen; Dautel;
(Gerlingen, DE) ; Flender; Thomas; (Eberdingen,
DE) ; Menonna; Antonio; (Ditzingen, DE) ;
Steichele; Stefan; (Gerlingen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mahie International GmbH |
Stuttgart |
|
DE |
|
|
Assignee: |
Mahie International GmbH
Stuttgart
DE
|
Family ID: |
49626829 |
Appl. No.: |
14/133124 |
Filed: |
December 18, 2013 |
Current U.S.
Class: |
123/90.6 |
Current CPC
Class: |
F01L 2001/0471 20130101;
F01L 2001/0475 20130101; F01L 1/047 20130101 |
Class at
Publication: |
123/90.6 |
International
Class: |
F01L 1/047 20060101
F01L001/047 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 19, 2012 |
DE |
102012223811.5 |
Claims
1. A camshaft of an internal combustion engine, comprising: at
least one function device connected therewith via a shaft-hub
connection, wherein the function device includes at least two
different function elements each operable for different
functions.
2. The camshaft according to claim 1, wherein the function device
couples to the camshaft via at least one of a thermal joining fit
and a longitudinal press fit.
3. The camshaft according to claim 1, wherein at least one function
element is at least one of a gear wheel, a coupling gear wheel, a
cam, a pump actuating device, an encoder wheel, a belt pulley, a
coupling, an Oldham coupling, and a chain wheel.
4. The camshaft according to claim 1, wherein the function device
is formed in one piece as a one-piece sintered component.
5. The camshaft according to claim 1, wherein the individual
function elements of the function device are fixedly connected to
one another via at least one of welding, soldering, screwing and
gluing together.
6. The camshaft according to claim 5, wherein the individual
function elements of the function device comprise positioning aids,
wherein the positioning aids allow fixing of the individual
function elements to one another in a predefined angular
position.
7. The camshaft according to claim 6, wherein the positioning aids
are at least one of formed as single flat and as multiple flat, in
particular as one of a two-flat and a triple-flat.
8. A function device of a camshaft, comprising: at least two
different function elements fulfilling different functions, wherein
the function device is at least one of formed in one piece as a
one-piece sintered component and the individual function elements
of the function device are connected to one another in a fixed
manner via at least one of welded, soldered, screwed and glued
together.
9. The function device according to claim 8, wherein at least one
function element includes at least one of a gear wheel, a coupling
gear wheel, a cam, a pump actuating device, an encoder wheel, a
belt pulley, a coupling, an Oldham coupling, and a chain wheel.
10. (canceled)
11. The camshaft according to claim 2, wherein at least one
function elements is at least one of a gear wheel, a coupling gear
wheel, a cam, a pump actuating device, an encoder wheel, a belt
pulley, a coupling, an Oldham coupling, and a chain wheel.
12. The camshaft according to claim 3, wherein the individual
function elements of the function device are fixedly connected to
one another via at least one of welding, soldering, fastening,
screwing, and gluing together.
13. The camshaft according to claim 12, wherein the individual
function elements of the function device comprise positioning aids,
wherein the positioning aids allow fixing of the individual
function elements to one another in a predefined angular
position.
14. The camshaft according to claim 13, wherein the positioning
aids are at least one of formed as single flat and as multiple
flat.
15. The camshaft according to claim 14, wherein the multiple flat
is at least one of two-flat and triple flat.
16. The function device according to claim 8, wherein the
individual function elements of the function device comprise
positioning aids, wherein the positioning aids allow fixing of the
individual function elements to one another in a predefined angular
position.
17. The function device according to claim 16, wherein the
positioning aids are at least one of formed as single flat and as
multiple flat.
18. The function device according to claim 17, wherein the multiple
flat is at least one of two-flat and triple-flat.
19. The function device according to claim 9, wherein the
individual function elements of the function device comprise
positioning aids, wherein the positioning aids allow fixing of the
individual function elements to one another in a predefined angular
position.
20. The function device according to claim 19, wherein the
positioning aids are at least one of formed as single flat and as
multiple flat, and wherein the multiple flat includes at least one
of two-flat and triple-flat.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to German Patent
Application DE 10 2012 223 811.5 filed Dec. 19, 2012, which is
hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to a camshaft of an internal
combustion engine having at least one function device connected
therewith via a shaft-hub connection according to the preamble of
claim 1. The invention additionally relates to a function device
for such a camshaft and to an internal combustion engine having at
least one such camshaft.
BACKGROUND
[0003] Generic camshafts are thoroughly known, just as connecting
function elements to such camshafts, for example via a thermal
joining fit. However, function devices such as for example gear
wheels, drive wheels, cams, pump actuating devices, such as for
example pump cams for a high-pressure pump or an Oldham coupling
for the rotary connection of vacuum or oil pumps are connected to
the camshaft by way of pressed-in or thermally joined plugs up to
now. For each function to be fulfilled, a separate function
element, such as for example gear wheels or cams are required here,
which for this purpose still have to be joined in a different way
if need be. When joining camshafts in a cover module, an additional
aggravating fact is that the space is limited, so that it is even
more complex to keep a plurality of function elements to join a
plug from the outside.
SUMMARY
[0004] The present invention therefore deals with the problem of
stating an improved embodiment for a camshaft of the generic type,
which is characterized in particular by a simplified
production.
[0005] According to the invention, this problem is solved through
the subjects of the independent claims. Advantageous embodiments
are subject of the dependent claims.
[0006] The present invention is based on the general idea of
equipping a function device on a camshaft with at least two
different function elements, which can each fulfil different
functions. The function elements combined in the function device in
this case are connected to the camshaft via a shaft-hub connection,
for example via a thermal joining fit or a longitudinal press fit.
The principle idea thus consists in combining or integrating as
many function elements as possible--however, at least two--in a
common function device and merely having to join this common
assembly, i.e. the function device, to the camshaft or a camshaft
tube. This offers substantial advantages, for example in the region
of the weight, since a function device which is put together of a
plurality of function elements is significantly lighter in
construction weight than function elements that are each separately
assembled. The function device according to the invention
additionally makes possible a higher torque transmission than can
be realised with a plug having a smaller internal diameter. At the
same time, the assembly is substantially simplified since all
function elements no longer have to be separately, i.e.
individually, joined to the camshaft, but merely the function
device, in which the individual function elements are already
aligned correctly to one another with respect to an angle of
rotation. This is a major advantage in particular if a camshaft is
assembled within a cylinder head cover, since according to common
knowledge only very little working space is available there. A
further advantage can be seen in an optimised weight distribution,
for example through masses which are opposed to a drive belt
pulley, so that the function device can be utilised for offsetting
unbalances at the same time.
[0007] Practically, at least one function element is a gear wheel,
in particular a coupling gear wheel, a cam, a pump actuating
device, for example in the manner of a cam, an encoder wheel, a
belt pulley, a coupling, in particular an Oldham coupling, or a
chain wheel. Even this non-conclusive listing gives an idea as to
how flexible the respective function device can be configured
through the joining of individual function elements.
[0008] According to a further advantageous embodiment and solution
according to the invention, the function device is formed in one
piece, in particular as a one-piece sintered component. In this
case, the individual function elements of the function device are
thus connected to one another as one piece, so that the function
device can be completely formed in one piece. This makes possible
in particular a rational production of the function device, since
an aligned joining together of the individual function elements
into the function device can be omitted. Alternatively to this, it
can obviously also be provided that the individual function
elements of the function device are connected to one another in a
fixed manner, in particular welded, soldered, screwed or glued
together. The separate formation of the individual function
elements in turn offers the major advantage that the function
device is extremely flexibly assemblable with respect to the
individual function elements. The individual function elements in
this case can be connected into the continuous function device via
a friction welding connection or by means of laser welding. In
order to be able to facilitate joining the individual function
elements into the common function device in an angularly correct
manner, positioning aids can be additionally provided on the
individual function elements, which allow fixing of the individual
function elements on one another exclusively in a predefined
angular position. Such positioning aids can for example be formed
as a single flat, for example as a clear grind, or as a multiple
flat, in particular as a dual flat or triple flat. In this case, a
function element thus has such a single or multiple flat as well as
an associated complementary recess arranged on the opposite face
end, as a result of which an angularly aligned axial inserting into
one another of the individual function elements into the common
function device is very easily possible. Obviously, the positioning
aids can be alternatively formed also as a pin or associated
opening, which allows a joining together of two function elements
in merely one single or a plurality of predefined angular
positions. These positioning aids can obviously be additionally
utilised also for further adjusting and positioning operations
after the assembly of the camshaft, for example when installing the
camshaft in the cylinder head.
[0009] If one of the function elements is designed as an Oldham
coupling, a pump can for example be coupled to the cylinder head to
the outside via this. Such an Oldham coupling makes possible a
coupling, in which the torque is transmitted between two parallel
shafts. Usually it consists of three discs, wherein the outer two
are fastened on the respective shafts or on the pump and on the
function element and the middle one is mounted with respect to the
two other discs in two slot and key connections which are
positioned orthogonally to one another. Such an Oldham coupling
makes possible in particular compensating for minor parallel
offsets between the camshaft and an axis of the pump, as a result
of which at least minor production inaccuracies can be offset
without problems, so that the entire construction altogether allows
greater production tolerances.
[0010] Further important features and advantages of the invention
are obtained from the subclaims, from the drawings and from the
associated Figure description with the help of the drawings.
[0011] It is to be understood that the features mentioned above and
still to be explained in the following cannot only be used in the
respective combination stated but also in other combinations or by
themselves, without leaving the scope of the present invention.
[0012] Preferred exemplary embodiments of the invention are shown
in the drawings and are explained in more detail in the following
description, wherein same reference characters relate to same or
similar of functionally same components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Here it shows, in each case schematically
[0014] FIG. 1 a sectional representation through a camshaft with a
function device according to the invention in an internal
combustion engine,
[0015] FIG. 2 a partially sectioned view of an internal combustion
engine according to the invention in the region of two camshafts
with the function device according to the invention,
[0016] FIG. 3 a representation as in FIG. 2, however with bearing
bridges,
[0017] FIG. 4 different views of an a sectional representation
through an embodiment of a function device according to the
invention,
[0018] FIG. 5-7 function devices in each case with different
function elements.
DETAILED DESCRIPTION
[0019] According to the FIGS. 1-3, a camshaft 1 of an internal
combustion engine 2 according to the invention comprises at least
one function device 3 that is connected to the camshaft 1 via a
shaft-hub connection, in particular via a press fit connection,
which is put together of at least two different function elements
4. The individual function elements 4 in this case fulfil different
functions and are merely combined in the common function device 3
to simplify the assembly. At least one function element 4 in this
case can for example be formed as a gear wheel 5, in particular as
a coupling gear wheel, as a cam, as a pump actuating device, as an
encoder wheel 6, as a belt pulley, as a coupling 7, in particular
as an Oldham coupling, or as a chain wheel 5'. The function device
3 represented according to FIG. 1 thus has three function elements
4, namely the coupling 7, the chain wheel 5' or gear wheel 5 as
well as the encoder wheel 6. By combining a plurality of function
elements 4 in a common function device 3 the production of the
camshaft 1 is clearly simplified, since all function elements 4 no
longer have to be separately joined to the camshaft 1 but merely a
common function device 3, as a result of which the joining process
can be significantly rationalised. The function device 3 with a
plurality of function elements 4 is additionally lighter in weight
than the respective separate function elements 4, as a result of
which a weight saving can be achieved, which in turn has a positive
effect on the fuel consumption.
[0020] Compared with a plug, the function device 3 according to the
invention additionally makes possible a higher torque transmission,
since via the transverse press fit, for example produced by means
of thermal joining, or a longitudinal press fit, a larger
force-transmitting contact area can be created. The combined
arrangement of a plurality of function elements 4 in a common
function device 3 additionally offers major advantages in
particular in the assembly of the function device 3 in a cover or a
cylinder head 8, since extremely confined space conditions are
usually encountered there.
[0021] According to FIG. 2, a view is shown from the top of the
cylinder head 8 of the internal combustion engine 2 with two
camshafts 1, wherein on the lower camshaft 1 the function device 3
according to the invention is arranged. The latter, in turn,
combines three function elements 4, namely the coupling 7, a gear
wheel 5, in the manner of a coupling gear wheel for coupling to the
second camshaft 1, as well as the encoder wheel 6. Mounting the
camshafts 1 on the cylinder head 8 in this case is effected by
means of a bearing frame 9, which is connected to the cylinder head
8, i.e. an engine block, via screws 10. By way of the coupling 7,
which in particular can be formed in the manner of an Oldham
coupling, a pump 11 for example can be coupled to the camshaft 1 in
a rotation-transmitting manner. The Oldham coupling in this case
makes possible an at least minor parallelism of the axes of the
camshafts 1 and the axis of the pump, as a result of which the
production precision need not be as high as without such an Oldham
coupling.
[0022] Considering FIG. 1 it is evident that the function device 3
is formed in one piece, in particular as a one-piece sintered
component, so that a separate and prior assembly of the individual
function elements 4 into the common function device 3 can be
omitted. Obviously, the individual function elements 4 of the
function device 3 can also be alternatively produced separately and
subsequently connected to one another into the common function
device 3 in a fixed manner, in particular welded, soldered, screwed
or glued together. In the representations according to FIG. 4 a
function device 3 is shown for example, which integrates two
function elements 4, namely the gear wheel 5 and the coupling 7 in
one piece. On the face end of the function device 3 facing away
from the coupling 7, a further function element 4, for example an
encoder wheel 6, could now be additionally attached or welded
on.
[0023] In order to facilitate an assembly of a multi-part function
device 3, positioning aids 12 can be provided on the individual
function elements 4, which allow fixing of the individual function
elements 4 to one another exclusively in a predefined angular
position. According to the lowermost representation in FIG. 4 and
the FIG. 6, the positioning aid 12 in this case is formed as a
two-flat, wherein for example the encoder wheel 6 has a recess that
is complementary thereto, in order to make thus possible an
angularly orientated fixing. In general, the positioning aid 12 in
this case can also be formed as a single flat or as a multiple
flat, in particular also as a triple flat. Generally, all other
non-round shapes are obviously also conceivable for the accurate
angular fixing of the individual function elements 4 on one
another.
[0024] With the function device 3 according to the invention, a
plurality of functions in the form of different function elements 4
can thus be combined and in the manner of a common function device
3, fixed on the camshaft 1 in a single operation. Because of this,
not only the assembly operation can be significantly rationalised,
but a cost-effective production achieved at the same time. By
combining individual function elements 4 into the common function
device 3, the major advantage is additionally obtained that
compared with a plug, higher torques can be transmitted and in
particular an assembly of the function device 3 is possible even
with comparatively little working space. Above all, this offers the
possibility of keeping the function device 3 according to the
invention with the individual function elements 4 in a cover and
subsequently slide the camshaft tube through the function elements
4 and the individual bearing points for example of the bearing
frame 9. Through the integration of a plurality of function
elements 4 in a common function device 3, merely the fixing of a
function device 3 is required in this case, which is clearly
simpler than the previously required fixing of the individual
function elements 4. With the function device 3 according to the
invention, a weight saving can be additionally achieved, since the
individual function elements 4 can be formed in a weight-reduced
manner. An unbalance offset in particular for example with respect
to a belt pulley 13 (see FIGS. 2 and 3) can also be achieved
through a special arrangement of the individual function elements
4.
* * * * *