U.S. patent application number 14/768359 was filed with the patent office on 2016-01-07 for stator for a camshaft adjuster, with a washer for reducing axial bearing play.
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 Olaf Boese, Holger Brenner.
Application Number | 20160003110 14/768359 |
Document ID | / |
Family ID | 49882741 |
Filed Date | 2016-01-07 |
United States Patent
Application |
20160003110 |
Kind Code |
A1 |
Brenner; Holger ; et
al. |
January 7, 2016 |
STATOR FOR A CAMSHAFT ADJUSTER, WITH A WASHER FOR REDUCING AXIAL
BEARING PLAY
Abstract
A stator assembly (1) for a camshaft adjuster (2), including a
stator (3) the exterior (5) of which has a toothed portion (4) for
absorbing torque provided by a crankshaft is provided. The stator
(3) includes a wall (6) which integrally forms the toothed portion
(4) and has an axially running cavity (7) for receiving a rotor
(9). At least one flange section (8) of the stator (3), which
protrudes radially inwards, forms an axial stop for the rotor (9).
A spacer disk (10) which is separate from the stator (3) and the
rotor (9) is present in the cavity (7) and sealingly rests on the
flange section (8). A vane-type hydraulic camshaft adjuster which
includes a rotor and a stator assembly of the above type is
provided.
Inventors: |
Brenner; Holger;
(Obermichelbach, DE) ; Boese; Olaf; (Nuernberg,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCHAEFFLER TECHNOLOGIES AG & CO. KG |
Herzogenaurach |
|
DE |
|
|
Assignee: |
SCHAEFFLER TECHNOLOGIES AG &
CO. KG
Herzogenaurach
DE
|
Family ID: |
49882741 |
Appl. No.: |
14/768359 |
Filed: |
November 11, 2013 |
PCT Filed: |
November 11, 2013 |
PCT NO: |
PCT/DE2013/200296 |
371 Date: |
August 17, 2015 |
Current U.S.
Class: |
123/90.12 ;
123/90.15 |
Current CPC
Class: |
F01L 1/3442 20130101;
F01L 2001/34479 20130101; F01L 1/46 20130101 |
International
Class: |
F01L 1/344 20060101
F01L001/344 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 27, 2013 |
DE |
10 2013 203 245.5 |
Claims
1-10. (canceled)
11. A stator assembly for a camshaft adjuster, the stator assembly
comprising: a stator for absorbing torque provided by a crankshaft,
the stator having a wall including a cavity extending in an axial
direction for the purpose of accommodating a rotor, at least one
radially inwardly protruding, integrally provided flange section of
the stator forming an axial stop for the rotor; and a spacing
washer separate from the stator and from the rotor and located in a
cavity between the stator and the rotor.
12. The stator assembly as recited in claim 11 wherein the spacing
washer has at least one recess extending from an outside to an
interior of the spacing washer and dimensioned to establish a
form-locked fit with the stator.
13. The stator assembly as recited in claim 12 wherein the at least
one recess includes a plurality of rectangular recesses distributed
evenly over a circumference of the spacing washer.
14. The stator assembly as recited in claim 11 wherein the spacing
washer has a central through-opening, and multiple indentations
extending in the axial direction are present between the central
through-opening and the outer circumference of the spacing
washer.
15. The stator assembly as recited in claim 14 wherein the
indentations are pockets or through-holes.
16. The stator assembly as recited in claim 14 wherein the
indentations are provided on the side of the spacing washer facing
the flange section, or pockets are present on q side of the spacing
washer facing away from the flange section.
17. The stator assembly as recited in claim 14 wherein at least one
nub extending in the axial direction is provided in the
indentation.
18. The stator assembly as recited in claim 15 wherein a hydraulic
medium conducting hole is provided in the pocket.
19. The stator assembly as recited in claim 15 wherein each pocket
is surrounded by a planarly designed, raised edge of the spacing
washer.
20. A vane-type, hydraulic camshaft adjuster comprising: the rotor
and the stator assembly as recited in claim 11.
Description
[0001] The present invention relates to a stator assembly for a
camshaft adjuster, including a stator which preferably has a
toothing on its outside for the purpose of absorbing torque
provided by a crankshaft, the stator having a wall which preferably
integrally forms the toothing and includes a cavity extending in
the axial direction for accommodating a rotor, at least one
integrally provided flange section of the stator, which protrudes
radially inwardly, directly or indirectly forming an axial stop for
the rotor.
BACKGROUND
[0002] Stator assemblies of this type are used in camshaft
adjusters, which are part of a timing assembly of internal
combustion engines. Timing assemblies of this type may include
fraction mechanism drives, such as chain and belt drives, for both
gasoline and diesel engines. Special camshaft adjusters, in which
the stator unit is formed as a single piece from the stator and the
cover, are known per se.
[0003] Established prior art is known, for example, from DE 10 2010
008 003 A1, in which a cell wheel of a device is described for
variably setting the control times of gas exchange valves of an
internal combustion engine, which includes a cylindrical peripheral
wall. The device furthermore has a drive wheel which is situated on
an outer lateral surface of the peripheral wall, a sealing cover,
which extends radially inwardly from an inner lateral surface of
the peripheral wall, and also has multiple projections, which
extend radially inwardly from the inner lateral surface of the
peripheral wall and in the axial direction from the sealing
cover.
[0004] U.S. Pat. No. 6,457,447 B1 furthermore describes a sealing
plate in a camshaft adjuster, which, however, abuts both the upper
side of the rotor and one side of the stator and is thus in sealing
contact with a gear wheel.
[0005] In the present prior art, the inner base surface of the
stator pot is usually re-machined to meet the high evenness
requirements of the axial bearing point. The better the evenness at
this point, the more the axial bearing play and thus the leakage
may be minimized.
[0006] However, processing this surface is complex and, in
particular, problematic at the transition between the cover surface
and the wall of the stator. Namely, a chamfer or a radius occurs
here, due to the special tool geometry. This chamfer or the radius
must be provided at the rotor and at the sealing strips, so that
the rotor and the stator have a sufficient ease of movement and the
adjusting process may be carried out. This inevitably results in a
circumferential leakage point on the camshaft adjuster, which,
however, should be avoided. A stator assembly should ultimately be
provided, which avoids the known disadvantages.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to eliminate the
known disadvantages and to provide an economically manufacturable
stator assembly, which, in turn, may be used in a hydraulic
camshaft adjuster, a leakage simultaneously being effectively
avoided.
[0008] Complex, re-machining steps of the stator base surface
should be avoided.
[0009] In a generic stator assembly, this object is achieved by the
fact that a spacing washer, which is separate from the stator and
from the rotor, is present in the cavity, for example between the
stator and the rotor, and is preferably situated in sealing contact
with the flange section.
[0010] Due to the additional use of a spacing washer which is
joined to the stator pot, a complex processing of the stator base
surface may be avoided. The spacing washer makes it possible to
provide a minimum axial play.
[0011] Advantageous specific embodiments are explained in greater
detail below.
[0012] It is thus advantageous if the spacing washer has at least
one recess which extends from the outside to the interior of the
spacing washer and which extends approximately in the direction of
the center of the spacing washer, the recess being dimensioned
and/or provided to establish a form-locked fit with the stator, the
stator having at least one inwardly projecting tab for this
purpose. In this way, a relative rotation of the spacing washer,
which may also be designed as a sealing disk, with the stator may
be prevented by using a form-locked fit. A stator assembly which
provides the requirements for a precision use may be created
thereby. While the preferred connection of the spacing washer to
the stator takes place with the aid of a form-locked fit,
force-fitted and/or integral connections have other advantages.
[0013] If a plurality of approximately rectangular recesses is
evenly distributed over the circumference, preferably if 2, 3, 4,
5, 6, 7 or 8 recesses are present, the anti-rotation protection is
ensured to a particular extent.
[0014] To improve an elasticity of the spacing washer in the radial
direction and/or the axial direction, it is advantageous if a
central through-opening is provided in the spacing washer and
multiple indentations extending in the axial direction are provided
between the central through-opening and the outer circumference of
the spacing washer.
[0015] It is advantageous if the indentations are designed as
pockets and/or through-holes. In the case of through-holes, the
weight of the spacing washer is also effectively reduced, while the
pockets also have a targeted oil conducting effect if oil is used
as the hydraulic medium. Other fluids are also conceivable as the
hydraulic medium.
[0016] It has turned out to be particularly advantageous if the
indentations are provided on the side of the spacing washer facing
the flange section and/or the pockets are present on the side of
the spacing washer facing away from the flange section.
[0017] If at least one nub extending in the axial direction,
preferably a plurality of evenly distributed nubs, is/are provided
in the indentation, the elasticity of the spacing washer, which may
also be designed as a sealing disk, pronounced in the axial
direction, may be improved. The spacing washer may be manufactured
from metallic material, such as a light metal alloy, but also a
steel alloy or a plastic material. In addition to the use of
plastic or metal for the spacing washer, rubber has also turned out
to be sufficiently resilient.
[0018] The sealing effect may be improved if a hydraulic medium
conducting hole, such as a bore, is provided in the pocket.
[0019] It is also advantageous if each pocket is surrounded by a
planarly designed, raised edge of the spacing washer/sealing disk,
since this also improves the sealing effect.
[0020] The present invention also relates to a vane-type hydraulic
camshaft adjuster, which includes a rotor and a stator assembly
according to the present invention.
[0021] It is also advantageous if the spacing washer has a chamfer
or rounding (concavity) on its outside, which is adapted to a
chamfer or rounding (concavity) existing between the wall of the
stator and the transition area between the wall and the flange
section. In this way, a manufacturing-related, circumferential
chamfer or a corresponding radius on the stator pot may be accepted
without requiring any re-machining The stator pot is the integral
combination/one-piece design of the stator wall and the flange
section(s) of the stator.
[0022] The elastic design of the spacing washer in the radial
direction for the purpose of adaptation to the stator contour is
also advantageous to ensure a circumferentially high sealing
function.
[0023] It is also effective if the underside of the spacing washer
is provided with an elastic profiling, which adapts to the surface
and evenness errors of the stator base surface when an axial force
is applied.
[0024] It is furthermore possible to implement oil channels in the
spacing washer for the purpose of supplying the pressure chambers
and the locking unit.
[0025] The design of the spacing washer with recesses on the
underside of the spacing washer for the purpose of implementing a
contact force via the oil pressure and thus a minimum axial play
during operation is also advantageous.
[0026] In other words, a spacing washer is inserted into the stator
pot for the purpose of avoiding a complex re-machining of the
stator base surface. Due to the separate processing of the spacing
washer or also a large number of spacing washers, for example by
machining only the spacing washer(s), i.e., with the aid of
grinding, a high accuracy of the evenness or the parallelism of the
surface may be achieved.
[0027] If this spacing washer, which may also be referred to as the
sealing disk, is inserted into the stator pot, the evenness errors
of the unprocessed stator base are compensated for. The
manufacturing-related chamfer at the stator cover transition is
caught by a corresponding chamfer on the spacing washer closest
thereto. A sharp-edged edge design between the rotor and stator may
furthermore be implemented, which results in fewer internal
leaks.
[0028] The spacing washer may be provided with an elastic design on
its outer diameter by removing material. As a result, the spacing
washer adapts to the vane running diameter on the stator pot and
forms an optimal seal here. Likewise, the circumferential leakage
point on a radial bearing may be sealed. Due to the elastic
adaptation of the disk to the stator diameter, more approximate
manufacturing tolerances of the two individual parts may be
allowed, which minimizes the cost pressure.
[0029] To compensate for major surface or evenness errors in the
stator base, an elastic, finely structured/profiled disk underside
surface may be designed. During assembly, the disk is pressed onto
the base surface with the aid of a stamp. The profiling is deformed
and optimally adapted in the process to the base surface. Due to
the elastic resilience of the base structure, a minimum axial play
may be implemented. This has a positive effect on leaks.
[0030] One additional option of limiting the axial bearing play is
to provide the washer with recesses on its back, which fill with
oil during operation and thus press the disk against the rotor.
[0031] Oil channels for supplying the pressure chambers or the
locking unit may also be implemented via the disk.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The present invention is also explained in greater detail
below with the aid of a drawing. Different specific embodiments are
illustrated.
[0033] FIG. 1 shows a longitudinal section of a camshaft adjuster
according to the present invention, according to a first specific
embodiment;
[0034] FIG. 2 shows an insulated spacing washer in a first, simple
specific embodiment;
[0035] FIG. 3 shows a section of the spacing washer from FIG. 2
along line III;
[0036] FIG. 4 shows a perspective view of the spacing washer from
FIGS. 2 and 3;
[0037] FIG. 5 shows a top view of a second specific embodiment of a
spacing washer, including recesses, for the purpose of implementing
elastic adaptations to the stator surfaces, which is suitable, in
particular, for use in wide rotor vanes;
[0038] FIG. 6 shows a view of the spacing washer from FIG. 5,
according to a section along line VI from FIG. 5;
[0039] FIG. 7 shows a perspective representation of the spacing
washer from FIGS. 5 and 6;
[0040] FIG. 8 shows a third specific embodiment of a spacing washer
according to the present invention, including a profiling on the
underside, for the purpose of implementing an elastic adaptation to
the stator base surface;
[0041] FIG. 9 shows a section of the spacing washer from FIG. 8
along line IX;
[0042] FIG. 10 shows a view of the spacing washer from FIGS. 8 and
9, seen from the flange section side;
[0043] FIG. 11 shows a fourth specific embodiment of a spacing
washer according to the present invention, including recesses on
the washer underside and at least one oil-conveying bore for each
pocket provided on the disk upper side, for the purpose of pressing
the spacing washer axially against the rotor, using the oil
pressure, which is also conducive to a minimization of the axial
play; and
[0044] FIG. 12 shows a section of the spacing washer in the
exemplary embodiment from FIG. 11 along line XII in FIG. 11.
DETAILED DESCRIPTION
[0045] The figures are only schematic and are used only for the
sake of understanding the present invention. Identical elements are
provided with identical reference numerals.
[0046] FIG. 1 shows a first specific embodiment of a stator
assembly 1 for a vane-type, hydraulic camshaft adjuster 2. Stator
assembly 1 includes a stator 3, which has a toothing 4 on its
outside 5.
[0047] Torque is transmitted from a crankshaft to stator 3 via
toothing 4, with the aid of a traction mechanism drive, which is
not illustrated, such as a chain or belt drive. Toothing 4 is an
integral part of wall 6 of stator 3, which is in the form of a
stator pot.
[0048] Stator 3 has a cavity 7, which extends in the axial
direction, flange sections 8 projecting from wall 6 of stator 3
radially inwardly into cavity 7 for the purpose of forming a stop
for a rotor 9 and also has a spacing washer 10 connected
therebetween. Spacing washer 10 may also be referred to as a
sealing disk. Flange sections 8 thus form the base of the stator
pot and have a central passage.
[0049] The state of contact between rotor 9 and flange sections 8
of stator 3 is also understood to be the intermediate connection of
another object.
[0050] Spacing washer 10 is situated axially between rotor 9 and
stator 3. On its side facing flange sections 8 in the
circumferential direction, spacing washer 10 has a chamfer 11,
which is adapted to a chamfer 12 of stator 3. The two chamfers 11
and 12 may also be designed as roundings.
[0051] Spacing washer 10 is preferably manufactured from plastic
and inserted into the stator to minimize the axial play.
[0052] FIGS. 2 through 4 show a first specific embodiment of a
spacing washer 10 according to the present invention, in a first,
particularly simple, design. Four recesses 13 are projectingly
provided on the outer circumference, in the direction of a center
14 of sealing disk/spacing washer 10.
[0053] FIGS. 5 through 7 show two specific embodiments of a spacing
washer 10 according to the present invention, indentations 15 of
different sizes being provided in the material of spacing washer
10. Indentations 15 here are designed all over as through-holes 16,
not all indentations 15 having to be designed as through-holes 16,
but also being able to remain designed as unperforated indentations
15.
[0054] Another specific embodiment of a spacing washer is provided
in FIGS. 8 through 10, a planar surface being formed on the upper
side and an indentation 15, which extends all the way to an edge
17, being formed on the underside, axially projecting/protruding
nubs 18, which are distributed evenly in a shared plane, being
furthermore present in the interior of indentation 15 in the
direction of flange sections 8.
[0055] In another modification, another exemplary embodiment is
represented in FIGS. 11 and 12, indentations 15 here having the
shape of pockets 19 on the upper side of spacing washer 10 facing
away from flange sections 8. However, a fluid supply passage is
provided, for example as a hydraulic medium conducting hole 20.
This hydraulic medium conducting hole 20 ensures a passage of
hydraulic medium from the upper side of spacing washer 10 to the
underside of spacing washer 10 for the purpose of improving a
pressing of spacing washer 10 onto rotor 9.
[0056] As a sealing disk, spacing washer 10 forms a seal to the
outside, i.e., so that a loss of hydraulic medium from the interior
of stator assembly 1, due to leaks, is prevented.
LIST OF REFERENCE NUMERALS
[0057] 1 stator assembly [0058] 2 camshaft adjuster [0059] 3 stator
[0060] 4 toothing [0061] 5 outside [0062] 6 wall [0063] 7 cavity
[0064] 8 flange section [0065] 9 rotor [0066] 10 spacing washer
[0067] 11 chamfer of the spacing washer [0068] 12 chamfer of the
stator [0069] 13 recess [0070] 14 center [0071] 15 indentation
[0072] 16 through-hole [0073] 17 edge [0074] 18 nub [0075] 19
pocket [0076] 20 fluid supply passage/hydraulic medium conducting
hole
* * * * *