U.S. patent application number 16/300078 was filed with the patent office on 2019-05-23 for actuating gear mechanism.
This patent application is currently assigned to Schaeffler Technologies AG & Co. KG. The applicant listed for this patent is Schaeffler Technologies AG & Co. KG. Invention is credited to Bastian Hain, Peter Zierer.
Application Number | 20190153909 16/300078 |
Document ID | / |
Family ID | 59101233 |
Filed Date | 2019-05-23 |
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United States Patent
Application |
20190153909 |
Kind Code |
A1 |
Hain; Bastian ; et
al. |
May 23, 2019 |
ACTUATING GEAR MECHANISM
Abstract
An actuating gear unit for an electrical camshaft adjuster is
provided. The actuating gear unit includes a housing with a
cylindrical basic shape, having an input-side end provided on the
drive side for coupling to an actuating motor, in particular an
electric motor, and an output-side end for coupling to an output
shaft. A rotation angle limiter for limiting the rotation of the
output shaft relative to the housing is arranged on the input-side
end.
Inventors: |
Hain; Bastian; (Creglingen,
DE) ; Zierer; Peter; (Erlangen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Schaeffler Technologies AG & Co. KG |
Herzogenaurach |
|
DE |
|
|
Assignee: |
Schaeffler Technologies AG &
Co. KG
Herzogenaurach
DE
|
Family ID: |
59101233 |
Appl. No.: |
16/300078 |
Filed: |
May 30, 2017 |
PCT Filed: |
May 30, 2017 |
PCT NO: |
PCT/DE2017/100455 |
371 Date: |
November 9, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01L 1/352 20130101;
F01L 2001/3521 20130101 |
International
Class: |
F01L 1/352 20060101
F01L001/352 |
Foreign Application Data
Date |
Code |
Application Number |
May 31, 2016 |
DE |
10 2016 209 362.2 |
Claims
1. (canceled)
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. (canceled)
7. (canceled)
8. (canceled)
9. (canceled)
10. (canceled)
11. An actuating gear mechanism designed as a strain wave gear, the
actuating gear mechanism comprising: a housing having: an
input-side end configured for attaching an actuating motor; and, an
output-side end configured for attaching an output shaft; and, a
rotation angle limiter for limiting rotation of the output shaft
relative to the housing, the rotation angle limiter arranged on the
input-side end of the housing.
12. The actuating gear mechanism of claim 11, further comprising: a
ring gear arranged within the housing, the ring gear configured to
be connected to the output shaft; and, a flexible transmission ring
arranged at least partially within the ring gear, the flexible
transmission ring having external toothing to engage internal
toothing of the ring gear.
13. The actuating gear mechanism of claim 12, wherein the flexible
transmission ring is a collared sleeve having a collar, the
rotation angle limiter arranged axially between the collar and the
housing.
14. The actuating gear mechanism of claim 12, wherein a
compensating coupling is arranged axially between the rotation
angle limiter and the external toothing of the flexible
transmission ring.
15. The actuating gear mechanism of claim 12, wherein the rotation
angle limiter is formed between the ring gear and the housing.
16. The actuating gear mechanism of claim 12, wherein the flexible
transmission ring is a collared sleeve having a collar mounted at
the input-side end of the housing, the collar arranged in front of
the rotation angle limiter.
17. The actuating gear mechanism of claim 16, further comprising a
thrust washer arranged between the collar and the housing.
18. The actuating gear mechanism of claim 17, wherein the rotation
angle limiter is formed between the thrust washer and the ring
gear.
19. The actuating gear mechanism of claim 18, wherein the thrust
washer includes at least two rotational stops that engage the ring
gear.
20. The actuating gear mechanism of claim 19, wherein an input-side
end of the ring gear includes at least two rotational stops that
engage the at least two rotational stops of the thrust washer.
21. The actuating gear mechanism of claim 19, wherein the thrust
washer includes at least two arc-shaped recesses that provide that
at least two rotational stops.
22. The actuating gear mechanism of claim 21, wherein the at least
two arc-shaped recesses comprise of a first recess and a second
recess.
23. The actuating gear mechanism of claim 22, wherein the first
recess provides a first rotational stop at a first end and a second
rotational stop at a second end.
24. The actuating gear mechanism of claim 22, wherein the first
recess provides a first rotational stop, and the second recess
provides a second rotational stop.
25. The actuating gear mechanism of claim 22, wherein the at least
two arc-shaped recesses are configured to provide unbalance
compensation.
26. The actuating gear mechanism of claim 11, wherein the housing
is configured as an input element of the actuating gear
mechanism.
27. The actuating gear mechanism of claim 26, wherein the housing
includes external toothing to interact with a chain, belt or
gear.
28. The actuating gear mechanism of claim 11, wherein the housing
is non-rotatable.
29. The actuating gear mechanism of claim 28, wherein the housing
is connected an engine block of an internal combustion engine.
30. An actuating gear mechanism designed as a strain wave gear for
an electric camshaft phaser, the actuating gear mechanism
comprising: a housing having: an input-side end configured for
attaching an actuating motor; and, an output-side end configured
for attaching a camshaft of an internal combustion engine; a ring
gear arranged within the housing, the ring gear configured to be
connected to the camshaft; a collared sleeve arranged at least
partially within the ring gear, the collared sleeve having:
external toothing to engage internal toothing of the ring gear;
and, a collar mounted at the input-side end of the housing; a
thrust washer arranged between the collar and the housing; and, a
rotation angle limiter for limiting rotation of the camshaft
relative to the housing, the rotation angle limiter formed between
an input-side end of the ring gear and the thrust washer.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. National Phase of PCT
Application No. PCT/DE2017/100455 filed May 30, 2017 which claims
priority to DE 102016209362.2 filed May 31, 2016.
TECHNICAL FIELD
[0002] This disclosure relates to an actuating gear mechanism which
can be used, in particular, in a motor vehicle and the housing of
which has a cylindrical basic shape, wherein there is a rotation
angle limiter between the housing and an output shaft that can be
connected to an output element of the actuating gear mechanism.
BACKGROUND
[0003] DE 10 2004 038 681 A1 discloses an electric-motor camshaft
adjuster in which there is a rotation angle limiter between an
output flange and a stop washer. The rotation angle limitation is
achieved through the interaction of a nose on the output flange
with two stops on the stop washer. The gear mechanism of the known
electric-motor camshaft adjuster can be designed as a swashplate
mechanism or simple internal eccentric mechanism.
[0004] In a camshaft adjustment system known from DE 10 2008 039
008 A1, there is rotation angle limitation between a stop washer,
which is connected to a camshaft, and a chain sprocket.
[0005] For rotation angle limitation, a transmission device which
is disclosed in DE 10 2010 050 814 A1 and is likewise suitable for
a camshaft adjuster has a plurality of noses, which each interact
with stops on a pocket. In this case, those parts which can pivot
relative to one another are provided with sliding support.
[0006] Further actuating gear mechanisms are disclosed by DE 10
2008 043 673 A1, DE 10 2006 028 554 A1 and US 2015/0033906 A1. DE
10 2011 004 070 A1 discloses a camshaft adjuster in which a first
mechanical stop is provided between the input part and the output
part, and a second mechanical stop is provided between the
actuating element and either the input part or the output part. A
device of this kind may solve the problem of jamming of the
actuating element but is not of compact construction. In
particular, it is not possible to dispense with a stop washer on
the output side.
SUMMARY
[0007] It is the underlying object of the disclosure to further
develop an actuating gear mechanism which has a rotation angle
limiter between an output shaft and a housing relative to the cited
prior art in respect of a particularly compact, easy-to-manufacture
construction.
[0008] According to the disclosure, this object is achieved by an
actuating gear mechanism having the features described herein and
illustrated in the Figures. This is an actuating gear mechanism
that has a housing with a cylindrical basic shape. Connections to
an actuating motor, on the one hand, and to an output shaft, on the
other hand, are provided on the two ends of the housing. The output
shaft to be connected to an output element of the actuating gear
mechanism can be pivoted over only a limited angular range relative
to the housing, wherein a rotation angle limiter provided for this
purpose is arranged not on the output-side end but on the
input-side end of the housing, which faces the actuating motor,
i.e. facing away from the output shaft.
[0009] The initially paradoxical rotation angle limiter between the
output shaft and the housing of the actuating gear mechanism on the
end thereof facing away from the output shaft has the advantage
that there is no need for any special stop element on the output
side of the mechanism, and therefore the connection between the
output element of the actuating gear mechanism and the output shaft
can be of particularly space-saving configuration. Instead, the
rotation angle limiter is relocated into the actuating gear
mechanism, namely to the input-side end thereof.
[0010] The rotation angle limiter itself can be formed with parts
that are present in the actuating gear mechanism in any case and
have geometrical features known per se. The interaction between a
nose or some other projection on a first part with flanks of
recesses in a second part may be mentioned by way of example. As
known, in principle, from the cited DE 10 2010 050 814 A1, for
example, it is possible here for a plurality of pairs of stop
contours to be distributed uniformly over the circumference of the
parts that can be pivoted to a limited extent relative to one
another. At least one of the parts that can be pivoted relative to
one another is processed by means of machining methods, for
example. This has the advantage that different maximum adjustment
angles can be defined by means of different machining processes,
based on starting components of identical geometry.
[0011] If a plurality of stops, at which stop contact takes place
simultaneously, is provided for mechanical limitation of the
adjustment range, the loads are distributed between the individual
stops and the material thickness thereof can be reduced. Even more
installation space is saved as a result. A gear mechanism of this
kind is of axially compact construction if the stops are arranged
offset relative to one another in the circumferential direction.
They are preferably situated in the same axial plane.
[0012] In a development of the stops, these are arranged
symmetrically in order to reduce the unbalance of the gear
mechanism. If the gear mechanism has an unbalance owing to other
components, arc-shaped recesses with two stop walls can be
provided, only one of which is used as a mechanical adjustment
angle limiter. The arc-shaped recess is "open" toward the other
stop, with the result that no mechanical stop contact takes place
here, the recess in the material serving instead for unbalance
compensation, for example. Two or more arc-shaped recesses can then
jointly delimit an adjustment range in both directions of
rotation.
[0013] In one embodiment, a ring gear is provided as the output
element of the actuating gear mechanism which is to be connected to
the output shaft. This ring gear can be of single- or multi-part
construction and preferably has a pot shape, wherein the pot base
faces the output-side end. A cylindrical section of the pot-shaped
ring gear is accordingly open toward the input-side end of the
actuating gear mechanism, wherein the rotation angle limiter is
preferably formed directly on that edge of the cylindrical section
of the ring gear which faces the input-side end. In this case, the
rotation angle limiter can be formed directly between the ring gear
and the housing. As an alternative, the rotation angle limiter can
be formed between the ring gear and a thrust washer connected in a
fixed manner to the housing.
[0014] The housing as a whole can be provided as the input element
of the actuating gear mechanism. For this purpose, the housing can
have an external toothing, which interacts with a traction means,
namely a chain or a toothed belt, or, as part of a gearwheel
mechanism, with at least one further gearwheel, for example. It is
likewise possible to implement embodiments in which the housing
forms a non-rotatable machine element and is connected, for
example, to an engine block of an internal combustion engine,
namely a reciprocating-piston engine, or is an integral component
of such an engine block.
[0015] Irrespective of whether the housing of the actuating gear
mechanism is a rotatable or a non-rotatable machine part, the
actuating gear mechanism is designed as a strain wave gear. By
virtue of the principle involved, a strain wave gear has a flexible
toothed transmission ring. The flexible transmission ring can be a
flex spline, for example. A flexible, ring-shaped, toothed
transmission ring without a flange or rim is referred to as a flex
spline. As an alternative, the flexible transmission ring can have
a pot shape. In one embodiment, the flexible transmission ring is a
collared sleeve. In this case, a radially outward-oriented flange,
also referred to as a collar, adjoins a cylindrical, toothed
section of the transmission ring. The collar of the flexible
transmission ring is preferably arranged on the input-side end of
the housing, in front of the rotation angle limiter, i.e. is
mounted in front of the rotation angle limiter. It is possible, in
turn, for a cover to be mounted in front of the collar on the
input-side end of the housing.
[0016] In respect of a possible geometrical configuration of a
flexible gearwheel designed as a collared sleeve which is suitable
for a strain wave gear, attention is drawn by way of example to EP
0 741 256 B1.
[0017] According to one possible embodiment, the actuating motor,
in particular electric motor, which is provided for the adjustment
of the actuating gear mechanism, is coupled by means of a
compensating coupling to mechanism elements of the actuating gear
mechanism. The compensating coupling, which is also referred to as
an Oldham coupling, allows the compensation of a parallel
misalignment and, to a small extent, also the compensation of
angular errors, between the actuating motor and the actuating gear
mechanism. The compensating coupling, or at least one Oldham disk
as the core element of the compensating coupling, is preferably
arranged axially between the rotation angle limiter and an external
toothing on the flexible transmission ring.
[0018] The actuating gear mechanism is suitable both for stationary
applications and for applications in vehicles. In particular, the
actuating gear mechanism is suitable for use in an electric
camshaft adjuster of an internal combustion engine or in a device
for adjusting the compression ratio of a reciprocating piston
engine.
[0019] An illustrative embodiment of the disclosure is explained in
greater detail below with reference to a drawing, in which, in
simplified form:
[0020] FIG. 1 shows an actuating gear mechanism in section,
[0021] FIG. 2 shows the actuating gear mechanism in an end
view.
[0022] An actuating gear mechanism denoted overall by the reference
character 1 is designed as a strain wave gear and is provided for
use in an electric camshaft adjuster of an internal combustion
engine. A substantially cylindrical housing 2 of the actuating gear
mechanism 1 has an external toothing 3, which enables the housing 2
and hence the entire actuating gear mechanism 1 to be driven with
the aid of a traction means (not shown), namely a chain or a
toothed belt.
[0023] The housing 2 rotates in a manner known per se at half the
speed of the crankshaft of the internal combustion engine.
[0024] An output element 4 of the actuating gear mechanism 1, which
is arranged within the housing 2, is designed as a ring gear and is
provided for connection to a camshaft (not shown), in particular an
inlet camshaft, of the internal combustion engine.
[0025] In the illustrative embodiment shown, the output element 4
is a one-piece transmission ring, wherein a cylindrical, internally
toothed section of the output element 4 is denoted by 5 and an end
section adjoining the latter is denoted by 6. In the end section 6
there is a central opening 7, which is concentric with the
rotational axis of the actuating gear mechanism 1 and hence also
with the camshaft. Connecting elements by means of which the end
section 6 of the output element 4 is connected to the camshaft are
not shown in the figures.
[0026] The camshaft, referred to in general as the output shaft,
which is connected in a fixed manner to the output element 4, can
be pivoted to only a limited extent relative to the housing 2,
which acts as an input element of the actuating gear mechanism 1.
For this purpose, a rotation angle limiter 8 is formed which is
arranged on the end of the housing 2 facing away from the output
shaft. To distinguish it from the output-side end of the housing 2,
the end on which the rotation angle limiter 8 is situated is
referred to as the input-side end. A thrust washer 9, which forms a
component of the rotation angle limiter 8, is connected in a fixed
manner to the housing 2 on the input-side end. The additional
component of the rotation angle limiter 8 is formed directly by the
cylindrical section 5 of the output element 4, i.e. the ring
gear.
[0027] An electric motor (not shown), which is provided as an
actuating motor for actuating the actuating gear mechanism 1, is
arranged on the first, input-side end of the actuating gear
mechanism 1, that is on the left in the arrangement according to
FIG. 1. The motor shaft of the actuating motor, which is concentric
with the rotational axis of the actuating gear mechanism 1, is
coupled to the actuating gear mechanism 1 by means of a
compensating coupling 10, namely an Oldham coupling, wherein the
compensating coupling 10 comprises an Oldham disk 11, which is to
be assigned to the actuating gear mechanism 1. Starting from a
normal position concentric with the rotational axis of the
actuating gear mechanism 1, the Oldham disk 11 can move to a
limited extent in two mutually orthogonal radial directions, thus
allowing a limited parallel misalignment between the rotational
axis of the actuating gear mechanism 1 and the rotational axis of
the actuating motor.
[0028] Via the Oldham disk 11, the actuating motor drives an inner
ring 12 of a wave generator 13. As long as the inner ring 12
rotates at the speed of the housing 2, the phase relation between
the camshaft coupled to the output element 4 and the crankshaft of
the internal combustion engine remains unchanged. The inner ring 12
of the wave generator 13 is intrinsically rigid and has an
elliptical outer contour. Rolling elements, namely balls 14,
rolling on the inner ring 12 are in contact with an outer ring 15,
which is flexible and adapts continuously to the elliptical shape
of the inner ring 12. The outer ring 15, in turn, is surrounded
directly by a flexible transmission ring 16, namely a collared
sleeve. The collared sleeve 16 has an external toothing 17, which
meshes with an internal toothing of the cylindrical section 5 of
the output element 4. Owing to the elliptical shape of the inner
ring 12, the external toothing 17 of the flexible transmission ring
16 is in engagement with the internal toothing of the ring gear 4
only in two diametrically opposite circumferential regions. As the
inner ring 12 is rotated, these engagement regions travel along the
circumference of the two transmission rings 4, 16. A slight
difference in the number of teeth of the external toothing 17, on
the one hand, and the internal toothing of the ring gear 4, on the
other hand, ensures that the ring gear 4 is turned slightly
relative to the housing 2 for each full revolution of the inner
ring 12. The actuating gear mechanism 1 designed as a strain wave
gear thus forms a gear mechanism with a large reduction ratio.
[0029] Several full revolutions of the inner ring 12 are required
to pivot the ring gear 4 from one stop position to the other stop
position, which is in each case determined by the rotation angle
limiter 8. On the first, input-side end of the housing 2, the
rotation angle limiter 8 is directly adjacent to a collar 18 of the
flexible transmission ring 16. The collar 18 of the flexible
transmission ring 16, i.e. the collared sleeve, merges into a
cylindrical section, denoted by 19, of the flexible transmission
ring 16, on which the external toothing 17 is located. The entire
flexible transmission ring 16, including the external toothing 17,
is manufactured as a one-piece sheet-metal component. When viewed
in the axial direction of the actuating gear mechanism 1, the
Oldham disk 11 is situated between the rotation angle limiter 8 and
the external toothing 17 of the collared sleeve 16. A cover 20,
which--like the flexible transmission ring 16--has the shape of a
cylindrical sleeve with an integrally formed flange, is mounted in
front of the flexible transmission ring 16 on the input-side end of
the housing 2. In the axial direction, i.e. the longitudinal
direction of the central axis of the actuating gear mechanism 1,
the cover 20 extends beyond the rotation angle limiter 8 as far as
the Oldham disk 11 and ends with a radially inward-oriented rim 21
directly in front of the wave generator 13. By virtue of the
overlap between various elements of the actuating gear mechanism 1
in the axial direction, in particular between the rotation angle
limiter 8 and the flexible transmission ring 16, the actuating gear
mechanism 1 is of very compact construction overall.
LIST OF REFERENCE CHARACTERS
[0030] 1 actuating gear mechanism [0031] 2 housing [0032] 3
toothing [0033] 4 output element, ring gear [0034] 5 cylindrical,
internally toothed section [0035] 6 end section [0036] 7 opening
[0037] 8 rotation angle limiter [0038] 9 thrust washer [0039] 10
compensating coupling, Oldham coupling [0040] 11 Oldham disk [0041]
12 inner ring [0042] 13 wave generator [0043] 14 rolling elements,
balls [0044] 15 outer ring [0045] 16 flexible transmission ring,
collared sleeve [0046] 17 external toothing [0047] 18 collar [0048]
19 cylindrical section [0049] 20 cover [0050] 21 rim
* * * * *