U.S. patent application number 09/826248 was filed with the patent office on 2002-10-10 for double clutch assembly.
This patent application is currently assigned to Mannesmann Sachs AG. Invention is credited to Dau, Andreas, Feldhaus, Reinhard, Orlamunder, Andreas, Peterseim, Michael, Randow, Anke, Randow, Jorg, Roll, Gerhard, Schierling, Bernhard.
Application Number | 20020144875 09/826248 |
Document ID | / |
Family ID | 7637474 |
Filed Date | 2002-10-10 |
United States Patent
Application |
20020144875 |
Kind Code |
A1 |
Dau, Andreas ; et
al. |
October 10, 2002 |
DOUBLE CLUTCH ASSEMBLY
Abstract
A first clutch area produces a first torque-transmitting
connection between a drive element and a first driven element, and
a second clutch area produces a second torque-transmitting
connection between the drive element and a second driven element. A
common engaging/disengaging mechanism actuates the first clutch
area and the second clutch area to produce and to nullify the first
and second torque-transmitting connections.
Inventors: |
Dau, Andreas; (Wurzburg,
DE) ; Orlamunder, Andreas; (Schweinfurt, DE) ;
Feldhaus, Reinhard; (Ebenhausen, DE) ; Randow,
Jorg; (Stammheim, DE) ; Roll, Gerhard;
(Eisenheim, DE) ; Schierling, Bernhard; (Kurnach,
DE) ; Peterseim, Michael; (Bergrheinfeld, DE)
; Randow, Anke; (Stammheim, DE) |
Correspondence
Address: |
Klaus P. Stoffel, Esq.
Cohen, Pontani, Lieberman & Pavane
551 Fifth Avenue, Suite 1210
New York
NY
10176
US
|
Assignee: |
Mannesmann Sachs AG
|
Family ID: |
7637474 |
Appl. No.: |
09/826248 |
Filed: |
April 4, 2001 |
Current U.S.
Class: |
192/48.8 ;
192/70.27; 192/89.25 |
Current CPC
Class: |
F16D 2021/0676 20130101;
F16D 13/583 20130101; F16D 13/52 20130101; F16D 13/385 20130101;
F16D 13/757 20130101; F16D 2021/0684 20130101; F16D 13/585
20130101; F16D 2021/0607 20130101; F16D 21/06 20130101 |
Class at
Publication: |
192/48.8 ;
192/70.27; 192/89.25 |
International
Class: |
F16D 013/50; F16D
021/02 |
Claims
We claim:
1. A double clutch assembly comprising a first clutch area for the
production of a first torque-transmitting connection between a
drive element and a first driven element, said first clutch area
comprising a first pressure plate, an engaging force-transmitting
component for transmitting an engaging force generated by a force
generating mechanism to the first pressure plate, whereby said
first clutch area can be actuated to produce the first torque
transmitting connection, a second clutch area for the production of
a second torque-transmitting connection between the drive element
and a second driven element, said second clutch area comprising a
second pressure plate, a first force storage element having one end
supported against the second pressure plate and an opposite end
supported against the engaging force-transmitting component,
whereby said second clutch area can be actuated to produce said
second torque transmitting connection, a common
engaging/disengaging mechanism for actuating said first and second
clutch areas to produce and to nullify the first and second
torque-transmitting connections.
2. A double clutch assembly as in claim 1 wherein said
engaging/disengaging mechanism actuates one of said first and
second clutch areas to produce one of said first and second
torque-transmitting connections while it actuates the other of said
first and second clutch areas to nullify the other of said first
and second torque-transmitting connections.
3. A double clutch assembly as in claim 1 further comprising an
essentially stationary intermediate disk assembly between said
first and second clutch areas, said first clutch area further
comprising a first clutch disk assembly located between said first
pressure plate and said intermediate disk assembly, the first
pressure plate being movable toward the intermediate disk assembly
to produce the first torque-transmitting connection, said second
clutch area further comprising a second clutch disk assembly
located between said second pressure plate and said intermediate
disk assembly, the second pressure plate being movable toward the
intermediate disk assembly to produce the second
torque-transmitting connection.
4. A double clutch assembly as in claim 1 wherein said common
engaging/disengaging mechanism comprises a force-storage unit which
pretensions either one of said first and second clutch areas to
maintain a respective one of said first and second
torque-transmitting connections.
5. A double clutch assembly as in claim 4 wherein said
force-storage unit comprises said engaging force-transmitting
component and said first force storage element.
6. A double clutch assembly as in claim 5 wherein said engaging
force-transmitting component comprises an area against which said
first force storage element is supported, said area moving away
from said second pressure plate when said engaging force is
transmitted to said first pressure plate.
7. A double clutch assembly as in claim 5 wherein said engaging
force-transmitting component comprises a second force storage
element having an area against which said first force storage
element is supported, said area being pretensioned toward said
second pressure plate.
8. A double clutch assembly as in claim 7 wherein said first force
storage element is permanently connected to said second force
storage element.
9. A double clutch assembly as in claim 8 wherein said first and
second force storage units are formed as a single component, said
first force storage element comprising a plurality of force storage
sections which project from the second force storage element toward
the second pressure plate.
10. A double clutch assembly as in claim 5 further comprising a
wear compensation assembly between said engaging force-transmitting
component and said first pressure plate.
11. A double clutch assembly as in claim 5 further comprising a
wear compensation assembly between said first force storage element
and said second pressure plate.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention pertains to a double clutch assembly,
comprising a first clutch area for the optional production of a
first torque-transmitting connection between a drive element and a
first driven element, and a second clutch area for the optional
production of a second torque-transmitting connection between the
drive element and a second driven element.
[0003] 2. Description of the Related Art
[0004] Double clutch assemblies of this type are used, for example,
in conjunction with variable gear transmissions which have two
transmission input shafts. Different gear stages can be engaged,
depending on which of the transmission input shafts is in the
torque-transmitting path after actuation of the associated clutch
area. To implement the engagements and disengagements of the
clutch, it is known in double clutch assemblies of this type that
each clutch area can have its own, separate engaging/disengaging
mechanism, so that, depending on the actuation or activation of one
of the engaging/disengaging mechanisms, one of the clutch areas can
be disengaged while the other is or becomes engaged. This leads to
a relatively complicated design, however, because the two
engaging/disengaging mechanisms, such as engaging/disengaging
piston-cylinder assemblies, must be installed in a small space and
thus staggered radially with respect to each other.
SUMMARY OF THE INVENTION
[0005] The object of the present invention is to improve the double
clutch assembly of the general type in question so that, with a
simpler design for executing engagements and disengagements, the
various clutch areas can be activated in a simplified manner.
[0006] This object is accomplished according to the invention by a
double clutch assembly, comprising a first clutch area for the
optional production of a torque-transmitting connection between a
drive element and a first driven element and a second clutch area
for the optional production of a torque-transmitting connection
between the drive element and a second driven element. The first
and second driven elements may be embodied as coaxially positioned
transmission input shafts.
[0007] The double clutch assembly according to the invention has a
common engaging/disengaging mechanism, by means of which the first
and the second clutch area can be actuated to produce or to nullify
the torque-transmitting condition.
[0008] According to the invention, therefore, the principle of
providing a separate engaging/disengaging mechanism for each clutch
area, these separate mechanisms then also being actuated
separately, is abandoned. Instead, a single mechanism of this type
is provided, which, depending on how it is actuated, can have the
effect either of engaging one of the clutch areas while disengaging
the other or of keeping both clutch areas in a state of partial
torque transmission. This considerably simplifies both the design
of a clutch assembly of this type and the measures required to
actuate the clutch.
[0009] In accordance with the invention, it is then also provided
preferably that, when one of the clutch areas has been actuated by
the engaging/disengaging mechanism to produce the
torque-transmitting condition, the other clutch area is actuated to
nullify the torque-transmitting condition.
[0010] The double clutch assembly according to the invention can
have, for example:
[0011] a first pressure plate for the first clutch area, this plate
being provided with a first friction surface, which can be brought
to rest against a first clutch disk assembly;
[0012] a second pressure plate for the second clutch area, this
plate being provided with a first friction surface, which can be
brought to rest against a second clutch disk assembly; and
[0013] an essentially stationary intermediate disk assembly, which
has, on one side, a second friction surface for the first clutch
area and, on the other side, a second friction surface for the
second clutch area, where, to create the torque-transmitting
condition for the first clutch area, the first pressure plate can
be moved toward the intermediate disk assembly and, to create the
torque-transmitting condition of the second clutch area, the second
pressure plate can be moved toward the intermediate disk
assembly.
[0014] To minimize the actuation effort required to actuate the
clutch assembly and to shift from one of the clutch areas to the
other, the double clutch assembly according to the invention is
provided with a force storage unit, by means of which one of the
clutch areas is kept pretensioned in its torque-transmitting
state.
[0015] A design which is very simple to build can be obtained in
this case by providing the force storage unit with a first force
storage element, which is or can be supported on one side against
the pressure plate of the one clutch area and on the other side
against a component which transmits the engaging force. By means of
this engaging force-transmitting component, an engaging force can
be transmitted from a force-generating mechanism to the pressure
plate of the other clutch area.
[0016] So that both clutch areas can take equal advantage of the
movements of the engaging force-transmission component when these
two clutch areas are being engaged and disengaged, the part of the
engaging force-transmission component which cooperates with the
first force storage element can be moved away from the pressure
plate of the one clutch area when an engaging force is transmitted
to the pressure plate of the other clutch area.
[0017] The effort required to construct the clutch assembly and to
actuate it to execute the various engagements and disengagements
can be further simplified by providing the engaging
force-transmission component with a second force storage element,
which has an area which cooperates with the first force storage
element, this area of the second component being pretensioned in
the direction toward the pressure plate of one of the clutch areas.
By keeping one of the clutch areas pretensioned in its
torque-transmitting state, the only measure which must be taken to
switch from the one clutch area to the other is to generate an
actuating force in a single direction, whereas shifting back in the
other direction can be accomplished simply by ceasing to generate
this force.
[0018] To simplify the design even further, the first force storage
element is permanently connected to the second force storage
element, the two preferably being designed as a single unit. This
can be realized, for example, by designing the first force storage
element with a plurality of force storage sections projecting from
the second force storage element toward the pressure plate of one
of the clutch areas.
[0019] To ensure, in a double clutch assembly according to the
invention, that the actuating characteristic and the clutch
characteristic do not change over the service life of the system,
that is, even after wear has occurred, the first force storage
element cooperates with the pressure plate of one of the clutch
areas and/or the engaging force-transmission component cooperate
with the pressure plate of the other clutch area by way of wear
compensation assemblies.
[0020] Other objects and features of the present invention will
become apparent from the following detailed description considered
in conjunction with the accompanying drawings. It is to be
understood, however, that the drawings are designed solely for
purposes of illustration and not as a definition of the limits of
the invention, for which reference should be made to the appended
claims. It should be further understood that the drawings are not
necessarily drawn to scale and that, unless otherwise indicated,
they are merely intended to conceptually illustrate the structures
and procedures described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 shows a partial, longitudinal cross section through a
first embodiment of a double clutch assembly according to the
invention;
[0022] FIG. 2 shows an axial view of a segment of a force storage
unit designed as a diaphragm spring, which can be used in the
double clutch assembly of FIG. 1;
[0023] FIG. 3 shows a view, corresponding to that of FIG. 2, of an
alternative design for a force storage unit, which simultaneously
exercises the functions of two force storage elements;
[0024] FIG. 4 shows a cross-sectional view along line IV-IV of FIG.
3;
[0025] FIG. 5 shows an enlarged, detailed view of the double clutch
assembly shown in FIG. 1, where a wear-compensation assembly is
also provided;
[0026] FIG. 6 shows a force-distance diagram, which illustrates the
change in the forces being exerted by the various force storage
elements during the execution of engagements and
disengagements;
[0027] FIG. 7 shows a clutch torque-distance diagram, which, in
agreement with the diagram of FIG. 6, illustrates the clutch
torques which occur during the execution of clutch actuations;
and
[0028] FIG. 8 shows an alternative design possibility of a double
clutch assembly according to the invention, this time in the form
of a wet-running clutch.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0029] In FIG. 1, a double clutch assembly 10 includes a flywheel
12, which can be or is connected to a drive shaft (not shown) such
as a crankshaft, for rotation in common with the shaft. In its
radially outer area, an intermediate disk element 14 is rigidly
connected to the flywheel 12; the cylindrical section 16 of this
disk element is bolted by a plurality of threaded bolts 18 or the
like to the flywheel 12. The intermediate disk element 14 works
together equally with the two different clutch areas 20, 22 of the
double clutch assembly 10.
[0030] The first clutch area 20 comprises a first pressure plate
21, the first friction surface 24 of which can be pressed against
friction linings 26 of a clutch disk 28 of the first clutch area
20. When this happens, the friction linings 26 of the clutch disk
28 are pressed against a second friction surface 30 of the first
clutch area 20, located on the intermediate disk element 14.
[0031] The double clutch assembly 10 also includes a second
pressure plate 32 for the second clutch area 22. This second
pressure plate 32 also has a first friction surface 34 of the
second clutch area 22; this friction surface can be pressed against
the friction linings 36 of the clutch disk 38 of the second clutch
area 22, which then has the effect of pressing the friction linings
36 against a second friction surface 39 of the second clutch area
22, which is also located on the intermediate disk 14.
[0032] The two clutch disks 28, 38 can be connected to the input
shafts of a gear transmission (not shown) for rotation in common
with the shafts, for which purpose the hub areas of the disks can,
for example, be provided with wedge-like teeth, which engage with
corresponding teeth on the shafts. The transmission input shafts
are preferably coaxial to each other and are supported to rotate
around a rotational axis A.
[0033] On a housing 40, connected nonrotatably to the flywheel 12,
a force storage element 46 in the form of a diaphragm spring, cup
spring, etc., is carried by way of a plurality of spacer bolts 42,
etc., and two wire rings 44 in the way normally used for clutches
of the "push" type. An actuating force-generating mechanism can
exert a force, illustrated by the force arrow F, on the radially
inward end 48 of the force storage element 46, thus pushing it in
the direction of the flywheel 12. As a result of the force acting
on the spring, the radially outer area 60 of the force storage
element 46 pivots away from the flywheel 12.
[0034] The radially outward-projecting sections 50 of the pressure
plate 21 of the first clutch area 20 pass through axially oriented
slots in the cylindrical section 16 of the intermediate disk
element and are connected rigidly there to a connecting assembly
52. This connecting assembly 52 can be either an essentially
circular cylindrical element or can comprise several connecting arm
sections 54, extending essentially in the axial direction, which
are bent over at the ends facing away from the pressure plate 21.
In this bent end area 56, there is, for example, a radially
outward-pretensioned wire ring 58, against which the radially outer
area 60 of the force storage element 46 is supported. The pressure
plate 32 of the second connecting area 22 also has several radially
outward-projecting sections 62, which engage between the individual
connecting arms 54 to create a nonrotatable connection between the
two pressure plates 21, 32. It should be pointed out here that the
two pressure plates 21, 32 can also be connected to the flywheel 12
and to the housing 40, respectively, by tangential leaf springs in
such a way that they are essentially nonrotatable with respect to
the intermediate disk element 14 but still have freedom of axial
movement and are pretensioned, for example, in a position away from
the intermediate disk element 14. These tangential leaf springs can
also act between the intermediate disk element 14 and the
respective pressure plates 21, 32 in such a way that, in a state in
which the pressure plates 21, 32 in question is resting with
frictional contact against its associated friction linings 26, 36,
the slanted section of a spring extends between the intermediate
disk element 14 and the pressure plates 21, 32. Since this slanted
section is at a certain angle of inclination with respect to a
plane orthogonal to the rotational axis A, it deflects the force as
a result of the tractional effect, as a result which the respective
pressure plates 21, 32 are pressed with even greater force against
the associated clutch disk 28, 38.
[0035] Another force storage element 64, which could be, for
example, a cup spring, is provided for the second clutch area 22.
This force storage element 64 is supported in its inner radial area
against the pressure plate 32 and in the radially outer area
against the radially outer area 60 of the force storage element 46.
If the force storage element 46 is now in the state shown in FIG.
1, in which it is not under the influence of the actuating
force-generating mechanism, then its radially outer area 60 presses
the force storage element 64 toward the pressure plate 32, which
then presses the clutch disk 38 against the intermediate disk
element 14. The force storage element 64 is thus under tension and
produces essentially the pressing force for the second clutch area
22. If now, proceeding from the this state, the second clutch area
22 is disengaged and the first clutch area 20 is engaged, then the
radially inner area 48 of the force storage unit 46 is acted on by
a force F, so that its radially outer area 60 is pivoted away from
the flywheel 12. This pivoting movement allows the force storage
unit 64 to relax, that is, to assume a less slanted position, until
ultimately there is no longer any pressure acting on the pressure
plate 32. By the action of the tangential leaf springs, for
example, this plate is then is lifted off the clutch disk 38.
During the actuating movement, the radially outer area 60 of the
force storage element 46, acting by way of the connecting assembly
52, carries the pressure plate 21 of the first clutch area 20 along
with it, so that the first friction surface 24 of this plate
approaches the friction linings 26 of the clutch disk 28. The
clutch area 20 is then kept in engagement by the continued action
of the force on the radially inner area of the force storage unit
46.
[0036] Through the suitable coordination of the spring
characteristics of the two force storage elements 46, 64 with each
other, it is possible to make sure that the torque increases gently
upon the execution of clutch engagements and disengagements. It is
also advantageous for the two force storage elements 46, 64 to be
designed so that they have a relatively long actuating distance in
the low force level range, as described in the following with
reference to FIGS. 6 and 7, so that production tolerances or clutch
wear occurring during operation will not lead to any significant
change in the actuating or engagement characteristics. An
embodiment of a force storage element 46, by means of which this
type of spring characteristic can be obtained, that is, a spring
characteristic with a flat curve in the low force range, is shown
in FIG. 2. It can be seen here that elastic tongues 72 known in and
of themselves project radially inward from a ring-shaped spring
body 70, whereas several projections 74, which are distributed
around the circumference, bent over slightly in the axial
direction, and separated from each other by recesses 76, project
radially outward from the area 60 of the force storage element.
[0037] FIG. 6 shows a diagram of the change in the clutch force
F.sub.K as a function of the actuating or engaging/disengaging
distance W. Two alternative characteristic clutch curves are shown,
one in solid line, the other in broken line; curve K.sub.22 shows
the change for clutch area 22, and curve K.sub.20 shows the change
for clutch area 20. E.sub.22 is the point along the actuating
distance axis ultimately reached in FIG. 1, i.e., the actuation
position in which the clutch area 22 is fully engaged. It can be
seen that the clutch force, which is determined ultimately by the
force storage element 64 and its characteristic, has reached a
maximum at this point. When a force is now applied to the radially
inner end of the force storage unit 46, which is thus moved toward
the flywheel 12, we can see a significant drop in the clutch force
of the clutch area 22, whereas there is a gradual increase in the
force in the clutch area 20. This gradual increase in force in
clutch area 20 is caused by the presence of the bent projections 74
in the radially outer area 60 of the force storage element 46,
which provide a certain elasticity in the path of force
transmission to the pressure plate 21. In the variant shown in
broken line, the two characteristic curves K.sub.22 and K.sub.20
are coordinated with each other in such a way that they have an
overlapping plateau region P in a center part of the actuating
distance curves between the two fully engaged positions E.sub.22
and E.sub.20. In this plateau region, neither of the two clutch
areas 20, 22 is fully engaged, although it is still possible for
each to transmit a certain drag torque. As a result of the presence
of this plateau region P, the wear which occurs during operation
can have only a slight or practically no influence on the clutch
force occurring in this state, because a small shift along the
distance axis W ultimately causes no change in the force. As force
continues to be applied to the force storage element 46, the force
transmitted to the clutch area 20 increases quickly, whereas,
through the relaxation of the force storage element 64, the clutch
force of the clutch area 22 decreases. Finally, the engaged
position E.sub.20 of the clutch area 20 is reached. The change in
the clutch torque which is obtained with a clutch force curve of
this type is shown in FIG. 7, also by the broken line.
[0038] The curves for the change in force and torque shown in FIGS.
6 and 7 by the solid lines, namely, K.sub.22', K.sub.20' and
M.sub.22', M.sub.20' illustrate the case in which there is almost
no plateau region P. This leads to a situation in which even very
small shifts caused by wear can indeed bring about a change in the
clutch force behavior, especially under conditions in which neither
of the clutches is completely engaged, but in compensation the two
engaged positions E.sub.22' and E.sub.20' move much closer
together, which means that the total actuating distance can be
reduced.
[0039] An alternative design for the force storage unit 46 is shown
in FIGS. 3 and 4. This force storage unit 46 combines in itself the
two force storage elements 46, 64, which were described above with
reference to FIG. 1. It can be seen here that the ring-shaped area
70 of the force storage element 46 is provided with several
essentially U-shaped slots 78, the open part of the U facing toward
the outside; these slots can be formed by punching, for example.
Each slot 78 is associated with a pair of straight slots 80, 82,
which are open radially toward the outside and extend radially
inward; there is one of these slots on each side of the U-shaped
slot 78. The inside end of each of these straight slots terminates
at the same level where the radially outward-pointing ends of the
sidepieces of the U-shaped slot 78 terminate. This has the effect
of creating a bending line B, and the plastic bending of the unit
along this bending line B thus allows the area 84, which is
radially outside the bending line B, to form a contact area, by
which the force storage element 46 can rest on the wire ring 58. At
the same time, the area 86, which is radially inside the bending
line B, can come to rest against the pressure plate 32 by its
radially inward end 88. This area 86 is therefore able to replace
the force storage element 64 of FIG. 1. An integral force storage
assembly is thus obtained, which simplifies considerably the
process of assembling a clutch mechanism of this type. The
configuration can be such that, even when the clutch area 22 is
fully engaged, the sections 86 are still not pressed completely
into the plane of the ring-shaped area 70 of the force storage unit
46. As an alternative, however, it is also possible to bend the
sections 86 so far over or, for example, to design them with such a
circumferential dimension that, even before the maximum pressure
has been applied, they are pushed into the plane or so close to the
plane of the ring-shaped body 70 that the remaining area of the
force storage element 46 arrives directly in contact with the
pressure plate 32. Such contact can be established, for example, by
the radially outward area of the tabs 90 formed between each pair
of slots 80, 82 and possibly also (when, for example, a raised
contact ridge or the like as shown in FIG. 1 is provided on the
pressure plate 32) by an area situated near the radially inner end
88 of the sections 86. It is thus possible to obtain a spring
characteristic which can act advantageously on the clutch actuation
process, as shown in FIG. 6. When a transition is to be made from
the engaged position of the clutch area 22 to the engaged position
of the clutch area 20 and a force is therefore exerted on the
pressure plate 21, the bent areas 84 are the first to be actuated.
If the force increases sufficiently, the entire circumferential
area, i.e., including the tabs 90 of the force storage unit 46,
comes to rest against the wire ring 56 and thus, as soon as the
plateau P is passed, the clutch area 20 experiences a rapid
increase in force.
[0040] It should also be remarked that FIG. 1 shows a clutch which,
in terms of its actuation principle, corresponds basically to a
"push" type of clutch; that is, pressure is exerted radially inward
on the force storage unit 46 in order to disengage the clutch area
22, which is to basically pretensioned by the force storage element
46 to remain in its torque-transmitting state. It is also possible,
of course, for the radially outside part of the force storage
element 46 to be supported on the housing 40, for example, and to
design a force storage element of the "pull" type, in which the
actuating force for disengaging the clutch area 22 must be applied
in the opposite direction, that is, away from the flywheel 12.
[0041] FIG. 5 shows a design variant of the double clutch assembly
according to the invention, in which wear compensation mechanisms
100, 102 are associated with both the first clutch area 20 and the
second clutch area 22. The two wear compensation mechanisms 100,
102 are essentially of the same design, so that their construction
is described in the following on the basis of wear compensation
mechanism 100 alone. This wear compensation mechanism 100 comprises
at least one play-providing device 104, which has a gripping
section 106, which passes through the pressure plate 32 and which
can come to rest against the intermediate disk element 14. A lever
element 108 connected to the gripping section extends radially
inward and is secured against rotation by a pin element 110, which
passes through an appropriate hole in the lever element 108. The
pin element 110 is surrounded by a compression spring 112, which is
supported at one end against the pressure plate 32 and at the other
end against the lever element 108 and which thus preloads the
gripping section 106 against the pressure plate 32 or a
pass-through opening provided in it to create a friction-locked
connection. In addition, the gripping section 106 is also
surrounded by a compression spring element 114, which preloads the
gripping section in the direction of the intermediate disk element
14. At the radially inside end, the lever element 108 extends over
two adjusting rings 116, 118 and engages in a circumferential
recess 120 in the adjusting ring 118, so that this ring is
prevented from rotating. The adjusting ring 116 is basically free
to rotate and is preloaded for rotation in the circumferential
direction with respect to the adjusting ring 118 by a preloading
spring or the like. The two rings 116, 118 rest against each other
by way of slanted surfaces, so that a relative rotation of the two
adjusting rings 116, 118 with respect to each other leads to an
axial expansion of the assembly formed out of these two rings 116,
118. The cup spring 64 acts on the adjusting ring 118 and, by
pushing it, also pushes the pressure plate 32 toward the clutch
disk 38. When, as a result of their rotation, the friction linings
36 are worn down, the gripping section 106 now comes to rest
against the intermediate disk element 14, which means that the
friction-locked connection between the gripping section 106 and the
pressure plate 32 is disconnected, and the entire play-providing
device 104 is shifted with respect to the pressure plate 32. Thus
the lever element 108 rises up off the adjusting ring 118. Because,
in the engaged state of this clutch area, the force storage unit 64
is still exerting force on the adjusting rings 116, 118, they
cannot execute any relative rotational movement. Only in the course
of a disengaging process, after the force storage unit 64 has
released the adjusting ring 118 or the actuating force has
decreased sufficiently, is the preload force sufficient at this
point to rotate the two rings 116, 118 with respect to each other
until, as a result of the axial expansion which occurs, the
adjusting ring 118 comes up against the play-providing device 104,
that is, against the lever element 108 thereof, the play-providing
device now being locked frictionally in place again. At this point,
the wear previously registered by the displacement of the
play-providing device 104 has been compensated exactly.
[0042] The wear compensation mechanism 102, which compensates for
any wear-induced displacement of the pressure plate 21 and thus of
the clutch assembly 52 in the direction of the housing 40,
functions in a similar manner. When, namely, the play-providing
device 104, that is, the gripping section 106 of this device,
strikes the housing 40, the lever element 108 against rises from
the adjusting rings 116, 118. This, again, occurs as the clutch
area 20 is in the process of becoming engaged, that is, while force
is being exerted on the radially inside end of the force storage
element 46 and the radially outside area 60 is approaching the
housing 40. When a disengaging process then follows, that is, when
the force storage element 46 relaxes again and thus reduces or
nullifies the actuation of the adjusting ring 118, the adjusting
rings 116, 118 can rotate again with respect to each other in the
circumferential direction until the adjusting ring 118 strikes the
lever element 108.
[0043] As a result of the wear compensation mechanisms 100, 102
described above, it can be ensured that the two force storage
elements 46, 64, which could also be replaced by the force storage
element shown in FIG. 3, will always be held in the same
installation position regardless of any wear which occurs, so that
a uniform clutch characteristic, which remains the same over the
entire service life of the unit, is present. It should be pointed
out that other types of wear compensation mechanisms could be used
in this area; in place of the adjusting rings rotating in the
circumferential direction, it would also be possible to use
wedge-like elements, which shift in the radial direction, or one of
the adjusting rings could be replaced by ramp surfaces, provided on
the pressure plate or the radially inward-pointing, flange-like
section 53 of the connecting assembly 52. It is obvious that
several of these play-providing devices 104 could be distributed
around the circumference.
[0044] Another modification of the double clutch assembly according
to the invention is shown in FIG. 8. The diagram of FIG. 8 shows a
wet-running clutch, in which the clutch disks 28, 38 now have
carriers 120, 122 for internal plates. The carriers are provided
with sets of teeth 124, 126, extending in the axial direction. By
these teeth, the carriers are connected nonrotatably at the
radially outward end to the internal plates 128, 130. Corresponding
teeth 132, 134, pointing radially inward, are provided on the
intermediate disk element 14. The external plates 136, 138 are
connected nonrotatably but with freedom of axial movement to these
external teeth. Friction linings are provided on the inside plates
128, 130 and/or on the outside plates 136, 138, so that, in the
engaged state of the clutch areas 20, 22, the external and internal
plates grip each other frictionally, and the assemblies of plates
are clamped between the friction surfaces 24, 30 of the first
clutch area 20 or between the friction surfaces 34, 39 of the
second clutch area. Obviously, a wet-running clutch assembly of
this type can be installed in a sealed housing, which encloses it
completely in a leak-proof manner. With respect to the design and
interaction of the force storage units 46, 64, reference can be
made to the preceding discussion.
[0045] Embodiments have been described above in which both clutch
areas of a double clutch assembly can be operated by a single
engaging/disengaging mechanism. It is obvious that several
different variants are possible here without departing from the
principle of the invention. For example, the flywheel 12 could be
designed as a double-weighted flywheel, or torsional vibration
dampers could be integrated into the individual clutch disks 28,
38. In addition, the orientation of the friction linings does not
have to be precisely radial; the linings can also be at a certain
angle with respect to the radial direction. It is also possible to
combine a double clutch assembly of this type with a
crankshaft-starter-generator system.
[0046] Thus, while there have shown and described and pointed out
fundamental novel features of the invention as applied to a
preferred embodiment thereof, it will be understood that various
omissions and substitutions and changes in the form and details of
the devices illustrated, and in their operation, may be made by
those skilled in the art without departing from the spirit of the
invention. For example, it is expressly intended that all
combinations of those elements and/or method steps which perform
substantially the same function in substantially the same way to
achieve the same results are within the scope of the invention.
Moreover, it should be recognized that structures and/or elements
and/or method steps shown and/or described in connection with any
disclosed form or embodiment of the invention may be incorporated
in any other disclosed or described or suggested form or embodiment
as a general matter of design choice. It is the intention,
therefore, to be limited only as indicated by the scope of the
claims appended hereto.
* * * * *