Flywheel for the friction clutch of a motor vehicle, the flywheel having two centrifugal masses and a friction device

A flywheel with two centrifugal masses having a hub disc and a cover-like actuator element, on which flywheel both the hub disc and the cover-like actuator element are designed so that the two parts actuate friction devices which act independently of one another. The one friction device is designed to prevent the loss of the screws used for the fastening to the crankshaft.

BACKGROUND OF THE INVENTION 
Field of the Invention 
The present invention generally relates to a flywheel arrangement with two 
centrifugal masses, the flywheel arrangement having a first centrifugal 
mass fastened to the crankshaft of an internal combustion engine, the 
first centrifugal mass defining an axis of rotation. There is also a 
second centrifugal mass, which second centrifugal mass is rotationally 
mounted on the first centrifugal mass by a bearing. The flywheel 
arrangement further includes a torsion damping device between the two 
centrifugal masses, which torsion damping device has several spring 
elements distributed concentrically with respect to the axis of rotation. 
In addition, the flywheel arrangement comprises at least one friction 
device located between the two centrifugal masses. There are also screws 
on a smaller intermediate diameter parallel to the axis of rotation, which 
screws connect the first centrifugal mass to the crankshaft. 
The flywheel arrangement also has cover-like actuator elements, for the 
spring elements, with circumferential control edges. The control edges are 
connected to the second centrifugal mass and are located on both sides of 
a hub disc with radially-projecting arms. The flywheel arrangement further 
includes a starter and shifting clutch, which shifting clutch is located 
on the side of the second centrifugal mass facing away from the first 
centrifugal mass. The shifting clutch is located on the second centrifugal 
mass with friction surfaces to clamp a clutch plate. 
BACKGROUND INFORMATION 
A flywheel arrangement with two centrifugal masses of the generic type 
described above is disclosed, for example, by German Unexamined Patent 
Application 40 06 639. 
OBJECT OF THE INVENTION 
The object of the present invention, on a flywheel arrangement with two 
centrifugal masses of the generic type described above, is to create a 
space-saving design which is easy to handle during installation and 
removal. 
SUMMARY OF THE INVENTION 
The present invention teaches that this object can be accomplished by a 
cover-like control or actuator element facing the starter and shifting 
clutch. The cover-like control element can extend radially inward, and the 
cover-like control element can be bent at a right angle toward the first 
centrifugal mass. The cover-like control element can essentially control a 
friction device, which friction device is preferably oriented concentric 
to the axis of rotation approximately radially inside the screws, which 
screws can be used to fasten the first centrifugal mass to the crankshaft. 
Thus, an additional function can be assigned to the cover-like actuator 
element, whereby the friction device can be located in a space-saving 
manner radially inside or inboard of the screws. 
The present invention also teaches that the friction device can be located 
near or located in contact with a sheet metal part, which sheet metal part 
can preferably be fastened by the screws to the first centrifugal mass. In 
the area radially inside the diameter formed by the screw heads, the sheet 
metal part is preferably bent axially toward the clutch essentially in the 
form of a tube segment. The sheet metal part can form a cylindrical seat 
on the outside diameter. In the radial space between the screw heads and 
the tube segment, there can preferably be a friction ring located on a 
cylindrical seat. The friction ring can be axially and frictionally held 
in place by a spring, which spring can be supported on the end of the tube 
segment. In addition, the friction ring can be actuated by areas of the 
cover-like actuator element. In this manner, the space radially inside the 
screw heads is preferably used for the location of a friction device. 
The present invention also teaches that areas of the cover-like actuator 
element can be engaged in recesses of the friction ring, whereby the 
recesses are preferably larger than the areas of the cover-like actuator 
elements in the circumferential direction. In this manner, it is 
essentially possible, depending on the particular operating requirements, 
to design the friction device as a friction device which can operate with 
some delay or slip. That means that essentially only after a certain 
rotational angle has been travelled can this friction action become 
effective. Such an arrangement can be advantageous, in particular, for 
friction devices which employ a relatively high friction force. 
The present invention teaches that the areas which can actuate the friction 
ring can preferably be formed by fingers which extend approximately 
radially inward. These fingers can then be engaged in corresponding 
recesses of the friction ring. 
As an additional advantageous feature, the cover-like actuator element can 
be provided, in the vicinity of the longitudinal axes of the screws, with 
passage openings for tools, which tools can be used to loosen and tighten 
the screws. In this manner, access to the screws for installation and 
removal can be essentially guaranteed. 
The present invention also teaches that the cover-like actuator facing the 
starter and shifting clutch can be extended radially inward, and can be 
bent at right angles toward the first centrifugal mass. In addition, the 
hub disc, which hub disc preferably runs essentially radially between the 
two cover-like actuator elements, can be bent in the vicinity of the 
outside diameter screw heads of the screws at approximately a right angle 
with respect to the first centrifugal mass. The hub disc can also form a 
bend, and can be fastened to the first centrifugal mass. A friction 
element is preferably located between the bent area of the hub disc and 
the input-side of the cover-like actuator element. In this manner, a 
friction device is preferably located in a space-saving manner directly 
inside the spring elements in the vicinity of the bend of the hub disc. 
The present invention also teaches that the friction device can be 
advantageously designed to generate the basic friction. The friction 
device can be centered with a friction ring concentric to the axis of 
rotation, which friction ring can be located in the bend of the hub disc 
and can be centered there. The friction device can be centered with a 
spring plate as well, which spring plate can be located between the 
friction ring and the output-side of the actuator element. As a result of 
this design configuration, it is essentially possible to generate a 
sufficient friction force even with low spring forces, since the friction 
surface can extend conically. 
The friction ring can also have an inside diameter, which inside diameter 
can be smaller than the outside diameter of the heads of the screws. Thus, 
the inside diameter of the friction ring can be used to essentially 
prevent the screws from being lost. As a result, the screws can be 
introduced into their position before the installation of the flywheel 
with the two centrifugal masses, essentially without losing the screws. 
The present invention also teaches that the actuator elements are 
preferably designed so that they fit tightly, at least radially outward, 
approximately around the contour of the spring elements. The control edges 
can preferably be formed by separately installed elements, and the seal 
can be provided radially inward between the bend of the hub disc and the 
friction ring. The seal can also be provided between the spring plate and 
the friction ring, or the output-side of the actuator element. As a result 
of this configuration, it is essentially possible to fill, at least 
partly, the interior space in which the spring elements can move with a 
lubricant, coolant or with a pasty or viscous material, to essentially 
create an additional damping action. 
The hub disc, in the area which is preferably bent toward the screw heads, 
can advantageously have a bearing point for a bearing, which bearing can 
support the second centrifugal mass. Thus, the hub disc, in spite of its 
essentially simple structure, can perform a dual function. 
The present invention teaches that the second centrifugal mass can 
preferably be mounted on the bearing by the cover-like actuator element 
facing the first centrifugal mass. Thus, the bearing is preferably 
installed on the hub disc in the immediate vicinity of the first 
centrifugal mass, which can essentially make it possible to have a very 
compact construction. 
The radially inner area of the actuator element is preferably thereby bent 
toward the first centrifugal mass. In this area, the actuator element is 
preferably placed on the bearing, whereby protection can be provided in 
one axial direction by a collar, and in the other axial direction, by a 
radially-inward extension of one of the actuator elements forming the 
control edges. 
The two actuator elements can preferably be tightly connected to one 
another radially outside the spring elements, preferably by welding. 
As an additional advantageous feature of the present invention, the hub 
disc can be bent radially toward the first centrifugal mass inside the 
arms to actuate the spring elements by a bend in the hub disc. The hub 
disc can extend radially inward with an additional bend, which additional 
bend can be in contact with the first centrifugal mass in this area and 
can be fastened by the screws, together with the first centrifugal mass, 
on the crankshaft. Radially inside the screw heads, the hub disc can be 
joined, in one piece, with a tube segment, which tube segment can 
preferably point away from the first centrifugal mass. As a result of this 
one-piece component, which is preferably fabricated from sheet metal, it 
is essentially possible to locate the bearing for mounting the second 
centrifugal mass in the area between the two bends. It is also essentially 
possible to locate a friction ring, for the load friction, on the tube 
segment radially inside the screw heads. The result is an essentially 
simple, rigid component which can perform several functions. 
As an additional feature of the present invention, the cover-like actuator 
element, in addition to actuating the friction devices, is preferably 
connected to the second centrifugal mass in an area which extends radially 
outside the spring elements. The cover-like actuator element can axially 
surround the second centrifugal mass radially outside the outside diameter 
of the second centrifugal mass. The cover-like actuator element can be 
designed, on the side facing away from the first centrifugal mass, for 
fastening the starter or shifting clutch. In this manner, the cover-like 
actuator element is preferably designed for the following functions: 
actuation of the spring elements, actuation of the friction devices, 
fastening of the second centrifugal mass, and the fastening of the starter 
or shifting clutch. 
When the word "invention" is used in this specification, the word 
"invention" includes "inventions", that is, the plural of "invention". By 
stating "invention", the Applicants do not in any way admit that the 
present application does not include more than one patentably and 
non-obviously distinct invention, and maintains that this application may 
include more than one patentably and non-obviously distinct invention. The 
Applicants hereby assert that the disclosure of this application may 
include more than one invention, and, in the event that there is more than 
one invention, that these inventions may be patentable and non-obvious one 
with respect to the other. 
One aspect of the present invention resides broadly in a friction clutch 
assembly, such as for a transmission for a motor vehicle, the friction 
clutch assembly comprising: a flywheel, a clutch housing, and a hub, which 
hub defines an axis of rotation and an axial direction parallel to the 
axis of rotation; a clutch disc disposed within the clutch housing, the 
clutch disc coaxially surrounding the hub; a pressure plate disposed 
within the clutch housing and movable in the axial direction, the pressure 
plate for applying an axial force to the clutch disc along the axial 
direction; a biasing apparatus for biasing the pressure plate in the axial 
direction; the flywheel comprising a first centrifugal mass and a second 
centrifugal mass; the first centrifugal mass being disposed substantially 
adjacent the clutch disc axially opposite the pressure plate; the clutch 
disc being disposed between the pressure plate and the first centrifugal 
mass; the second centrifugal mass being disposed adjacent the first 
centrifugal mass axially opposite the clutch disc and the pressure plate; 
the clutch disc comprising friction linings disposed substantially between 
the pressure plate and the first centrifugal mass; a hub disc; the hub 
disc being disposed to coaxially surround the hub; the hub disc being 
disposed adjacent the second centrifugal mass; elements for connecting the 
hub disc to the second centrifugal mass; a friction device; the friction 
device being disposed substantially adjacent the hub; an apparatus for 
providing frictional engagement with the friction device; the apparatus 
for providing frictional engagement with the friction device being 
disposed adjacent the second centrifugal mass; at least a portion of the 
apparatus for providing frictional engagement with the friction device 
being disposed substantially adjacent the hub; the at least a portion of 
the apparatus for providing frictional engagement with the friction device 
being disposed adjacent and in contact with the friction device; and the 
friction device being frictionally engaged with the apparatus for 
providing frictional engagement with the friction device. 
Another aspect of the present invention resides broadly in a friction 
clutch assembly, such as for a transmission for a motor vehicle, the 
friction clutch assembly comprising: a flywheel; a clutch housing; a hub 
defining an axis of rotation and an axial direction parallel to the axis 
of rotation; a clutch disc disposed within the clutch housing, the clutch 
disc coaxially surrounding the hub; a pressure plate disposed within the 
clutch housing and movable in the axial direction, the pressure plate for 
applying an axial force to the clutch disc along the axial direction; a 
device for biasing the pressure plate in the axial direction; the flywheel 
comprising a first centrifugal mass and a second centrifugal mass; the 
first centrifugal mass being disposed substantially adjacent the clutch 
disc axially opposite the pressure plate; the clutch disc being disposed 
between the pressure plate and the first centrifugal mass; the second 
centrifugal mass being disposed adjacent the first centrifugal mass 
axially opposite the clutch disc and the pressure plate; the clutch disc 
comprising friction linings; the friction linings being disposed 
substantially between the pressure plate and the first centrifugal mass; a 
hub disc; the hub disc being disposed to axially surround the hub; the hub 
disc being disposed adjacent the second centrifugal mass; devices for 
connecting the hub disc to the second centrifugal mass; the connecting 
devices being disposed substantially adjacent the hub; a first friction 
device; a second friction device; the first friction device being disposed 
substantially adjacent the hub; the first friction device being disposed 
at a first radial distance with respect to the hub; the second friction 
device being disposed at a second radial distance with respect to the hub; 
the second radial distance being substantially greater than the first 
radial distance with respect to the hub; an apparatus for providing 
frictional engagement with the first friction device and the second 
friction device; the apparatus for providing frictional engagement with 
the first friction device and the second friction device being disposed 
substantially axially between the clutch disc and the second centrifugal 
mass; a first portion of the apparatus for providing frictional engagement 
with the first friction device and the second friction device being 
disposed substantially adjacent the hub; the first portion of the 
apparatus for providing frictional engagement with the first friction 
device and the second friction device being disposed adjacent and in 
contact with the first friction device; the first friction device being 
frictionally engaged with the apparatus for providing frictional 
engagement with the first friction device and the second friction device; 
the hub disc having an outer circumference; the hub disc extending in a 
radial direction with respect to the hub; the hub disc comprising a bent 
portion; the bent portion extending in an axial direction toward the 
second centrifugal mass; the bent portion of the hub disc being disposed 
substantially adjacent the second radial distance with respect to the hub; 
the second friction device being disposed substantially between the bent 
portion of the hub disc and the apparatus for providing frictional 
engagement with the first friction device and the second friction device; 
and the second friction device being frictionally engaged with the 
apparatus for providing frictional engagement with the first friction 
device and the second friction device.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows a longitudinal section through a flywheel 1 with two 
centrifugal masses 2 and 4. The flywheel 1 preferably has a first 
centrifugal mass 2 which can be fastened by screws 10 to a crankshaft (as 
shown in FIG. 1a). In the fastening area, the first centrifugal mass 2 can 
preferably extend essentially radially and, in particular, perpendicular 
to the axis of rotation 3. The first centrifugal mass 2 can have, for 
example in its radially outer area, gear teeth for engagement with the 
starter gear wheel. 
On the side of the screw heads 11 of the screws 10, there can be a torsion 
damping device 6 and the friction elements of a starter or shifting clutch 
17, which torsion damping device 6 and friction elements can be arranged 
radially on top of one another. The torsion damping device 6 can include 
several spring elements 7 which can preferably be located on an 
intermediate diameter concentric to the axis of rotation 3. The spring 
elements 7 are preferably designed as coil springs. These spring elements 
7 can be actuated, on one hand, by structural elements, which structural 
elements are preferably firmly connected to the second centrifugal mass 4. 
The spring elements 7 can be actuated, on the other hand, by a central 
element or hub disc 16, which hub disc 16 can preferably be connected to 
the first centrifugal mass 2. The central element 16 is preferably 
designed in the form of a hub disc 16 which can have radially-projecting 
arms 37 to actuate the spring elements 7. 
Radially inside the spring elements 7, the hub disc 16 is preferably bent 
at a right angle in the axial direction, essentially forming a bend 36 of 
the hub disc 16. The hub disc 16 then preferably extends to the first 
centrifugal mass 2, where the hub disc 16 can have a second bend 38. The 
hub disc 16 can then extend radially inward toward the axis of rotation 3. 
Radially inside the screw heads 11 of screws 10, the hub disc 16 can 
preferably form a sheet metal part 28, which sheet metal part 28 can be 
joined in a single piece with a concentric tube segment 30. The concentric 
tube segment 30 can point away from the first centrifugal mass 2. Between 
the two bends 36 and 38 there is a cylindrical area on which a bearing 5 
is preferably seated along the inside diameter of the bearing 5. 
Therefore, in accordance with an embodiment of the present invention, the 
spring elements 7 of the torsion damping device 6 can be actuated by the 
hub disc 16. For this purpose, the hub disc 16 preferably has 
radially-projecting arms 37 adjacent and in contact with spring elements 
7. Toward the radially inner area of the hub disc 16, the hub disc 16 can 
be designed with bend 36 and bend 38. The bearing 5 can be located on the 
hub disc 16 preferably in the area between the bend 36 and bend 38. The 
spring elements 7 of the torsion damping device 6 can also be actuated by 
cover-like actuator elements 12 and 13. 
All of the components which can preferably be connected to the second 
centrifugal mass 4 and can rotate can be mounted on the outside diameter 
of the bearing 5. Such components can include the two cover-like actuators 
12 and 13, which cover-like actuators 12 and 13 can be located next to the 
arms 37 of the hub disc 16. The radially outwardly extended area of the 
cover-like actuator element 12 can support the second centrifugal mass 4. 
The additional components which are connected to the second centrifugal 
mass 4 can also include the friction clutch 17 with its circulating or 
rotating parts. The two cover-like actuator elements 12 and 13 can be 
connected radially outside the spring 7, where they are preferably welded 
tight. The cover-like actuator elements 12 and 13 can extend approximately 
around the contour of the spring elements 7. On the sides facing one 
another, the cover-like actuator elements 12 and 13 each preferably have 
respective elements 14 and 15, which elements 14 and 15 preferably 
comprise control edges for the actuation of the spring elements 7. 
In accordance with a preferred embodiment of the present invention, since 
the hub disc 16 is preferably connected to the first centrifugal mass 2 
and the cover-like actuator element 13 is preferably tightly connected 
with the cover-like actuator element 12, the bearing 5 can essentially 
permit the cover-like actuator element 13 and the radially-projecting arms 
37 of the hub disc 16 to rotate with respect to one another. 
As shown in FIG. 1, radially inside the spring elements 7, the output-side 
of the actuator element 12 can be recessed toward the hub disc 16, where 
the actuator element 12 can support a spring plate 35. The spring plate 35 
can act, by a friction ring 34, on the bend 36 of the hub disc 16. The 
friction ring 34 can thereby be centered in the vicinity of the bend 36, 
and the friction ring 34 can represent or act on the hub disc 16 against 
the generation of a friction force. As shown in FIG. 1, the friction ring 
34 and the spring plate 35 are generally designated as friction device 9. 
The friction ring 34 can thereby be oriented concentric to the axis of 
rotation 3 and the friction ring 34 can have an inside diameter which is 
preferably somewhat smaller than the outside diameter of all the screw 
heads 11 of the screws 10. In this manner, the screws 10 can be installed 
before the installation of the flywheel arrangement with the two 
centrifugal masses essentially without any danger of losing the screws. 
The actuator element 12 can preferably be extended radially inward beyond 
the friction ring 34. The actuator element 12 can be bent at a right angle 
toward the first centrifugal mass 2, and in the vicinity of the screw 
heads 11, the actuator element 12 can have fingers 26, which fingers 26 
can extend radially inward into recesses 33 of a friction ring 31. The 
friction ring 31 can preferably be friction-fitted onto the outside 
diameter of the tube segment 30. As shown in FIG. 1, this arrangement is 
generally designated as the friction device 8. On the end of the tube 
segment 30 there can be a spring 32, which spring 32 can bias the friction 
ring 31 on the radially extending portion of the sheet metal part 28. The 
friction ring 31 can thereby be actuated by the fingers 26, which fingers 
26 run radially inward of the extension 27 of the actuator element 12. For 
this purpose, in the friction ring 31 there are preferably recesses 33, 
which are preferably circumferentially larger than the fingers 26. A 
friction with a certain degree of slip can thereby essentially be 
achieved. 
Adjacent to the actuator element 12, pointing away from the first 
centrifugal mass 2, there can be a clutch plate 23, which clutch plate 23 
can be fastened non-rotationally by means of a hub 24 on a transmission 
shaft (see FIG. 1a). The clutch plate 23, on the radial outside, can 
support friction linings (see 34' in FIG. 1a), which friction linings can 
be clamped between the second centrifugal mass 4 and an application plate 
21 of the friction clutch 17. The application plate 21 can thereby be 
non-rotationally located inside a clutch housing 18 by tangential leaf 
springs 22, for example, which tangential leaf springs 22 can essentially 
allow the application plate 21 to be displaced axially. The clutch housing 
18, in the vicinity of the outside circumference, can be firmly connected 
to the radially outer area of the actuator element 12. Between the 
application plate 21 and the clutch housing 18, there can be a membrane 
spring 19, which membrane spring 19 can be supported on an intermediate 
diameter of the housing 18 by spacer bolts 25. The membrane spring 19 can 
be in contact, by its radially outside circumference, with the application 
plate 21, whereby the membrane spring 19 can apply a load to the 
application plate 21 toward the second centrifugal mass 4. Toward the 
radial inside, the membrane spring 19 can be provided with flexible tabs 
20 which--similar to the clutch plate 23--can preferably have passage 
openings corresponding to matching passage openings 29 in the actuator 
element 12, so that it can be possible to tighten and loosen the screws 10 
using a tool. 
It should be understood that in at least one embodiment of the present 
invention, the friction clutch as shown in FIG. 1 may be considered to be 
shown to scale. 
As a result of the design of the actuator element 12 described and 
illustrated above, the actuator element 12 can essentially be used for 
many different functions. Radially outside the springs 7, the actuator 
element 12 can preferably run parallel to the first centrifugal mass 2 
toward the radial outside, and in this area, the actuator element 12 can 
preferably support the second centrifugal mass 4. The second centrifugal 
mass 4 can be located separately as a ring concentric to the axis of 
rotation 3. Then the actuator element 12 preferably surrounds the second 
centrifugal mass 4 and the clutch plate 23 in a basin-shaped fashion, 
pointing away from the first centrifugal mass 2. The actuator element 12 
also preferably has facilities in the terminal area for fastening the 
clutch housing 18 of the friction clutch 17. 
In accordance with an embodiment of the present invention, the actuator 
elements 12 and 13 are preferably contoured to essentially surround the 
spring elements 7. Specifically, the actuator element 13 preferably 
extends in the radial direction essentially adjacent the first centrifugal 
mass 2, whereas the actuator element 12 preferably forms a contoured shape 
essentially enclosing a large portion of the circumference of the spring 
elements 7. Radially closely outside the spring elements 7, the actuator 
element 12 can extend in the axial direction toward the first centrifugal 
mass 2. In this area, the actuator elements 12 and 13 are preferably 
joined together and tightly connected with one another, preferably by 
welding. Radially outside the connection of actuator elements 12 and 13, 
the actuator element 12 preferably extends radially outward and 
essentially between the first centrifugal mass 2 and the second 
centrifugal mass 4. In this area, the actuator element 12 is preferably 
located adjacent and fastened together with the second centrifugal mass 4. 
In this manner, the actuator element 12 can support the second centrifugal 
mass 4. Radially inside the spring elements 7, the actuator element 12 is 
preferably contoured into a curve in a direction toward and adjacent the 
hub disc 16. Radially further inside the spring elements 7, the actuator 
element 12 preferably bends at an essentially right angle toward the first 
centrifugal mass 2. The actuator element 12 then preferably extends in an 
essentially axial direction toward the first centrifugal mass 2. In the 
area closely radially outside the friction device 8, the actuator element 
12 can preferably bend radially inward toward the friction device 8. The 
actuator element 12 preferably extends radially inward whereby the fingers 
26 of the actuator element 12 can be in contact with the friction device 
8. 
Radially inside the springs 7, the actuator element 12 can be recessed 
inward and can support a spring plate 35 for a friction ring 34, which 
friction ring 34 can preferably be adjacent to the bend 36 of the hub disc 
16 and here preferably generates the basic friction. Radially inside the 
friction ring 34, the actuator element 12 can be bent at a right angle 
toward the screws 10, and a short distance in front of the screw heads 11, 
the actuator element 12 can swing radially inward with fingers 26, which 
fingers 26 can actuate the friction ring 31. In this radially inner area, 
the actuator element 12 is preferably provided with passage openings 2 
which essentially make it possible to introduce tools to tighten and 
loosen the screws 10. The hub disc 16, as a result of its shape, can also 
essentially perform multiple functions, and preferably supports, on one 
hand, in a cylindrical area between the two bends 36 and 38, the bearing 5 
for essentially all the parts of the second centrifugal mass 4. On the 
other hand, the hub disc 16 is preferably designed, in its radially inner 
area, radially inside the screws 10, as a one-piece tube segment 30 which 
preferably supports the friction device 8. Both the actuator elements 12 
and 13 are preferably connected tightly to one another radially outside 
the springs 7--e.g. by a weld--so that the interior space can be filled, 
at least partly, with a lubricant, coolant or with a pasty or viscous 
material, to create an additional damping device. Radially inward, this 
space is sealed, on one hand, by providing the bearing 5 with at least one 
seal, and, on the other hand, by essentially having the friction device 9 
also perform a sealing action. 
Summarizing, in accordance with an embodiment of the present invention, in 
the area radially outside the springs 7, the actuator elements 12 and 13 
can preferably be connected, for example, by a weld. In the area radially 
outside the screws 10, there can preferably be a seal adjacent the bearing 
5. The seal for the bearing 5 can be provided by the actuator element 13. 
The radially inner end of the actuator element 13 can abut the bearing 5. 
The radially inner end of the actuator element 13 can then extend in 
essentially the axial direction and then curve radially inward thereby 
essentially surrounding one edge of the bearing 5. On the other hand, the 
control edge 15 of the actuator element 13 can extend radially inward 
whereby the radially inner end of the control edge 15 can abut the other 
edge of the bearing 5. Another seal can also preferably be provided by 
means of the friction device 9. As a result of such seals along with the 
connection between the actuator elements 12 and 13, the interior space 
between the actuator elements 12 and 13 can be sealed and can thereby be 
filled, at least partially, with a damping medium such as a lubricant or 
coolant or viscous material. 
One feature of the invention resides broadly in the flywheel with two 
centrifugal masses, comprising a first centrifugal mass fastened to the 
crankshaft of an internal combustion engine and defining an axis of 
rotation, a second centrifugal mass which is rotationally mounted on the 
first centrifugal mass by means of a bearing, a torsion damping device 
between the two centrifugal masses with several spring elements 
distributed concentrically to the axis of rotation, at least one friction 
device between the two centrifugal masses, screws on a smaller 
intermediate diameter parallel to the axis of rotation which connect the 
first centrifugal mass to the crankshaft, cover-like actuator elements for 
the spring elements with circumferential control edges which are connected 
to the second centrifugal mass and which are located on both sides of a 
hub disc with radially-projecting arms, a starter clutch or clutch on the 
side of the second centrifugal mass facing away from the first centrifugal 
mass, which clutch is located on the second centrifugal mass with friction 
surfaces to clamp or fix a clutch plate, characterized by the fact that 
the cover-like actuator element 12 facing the starter and shifting clutch 
17 is extended radially inward and is bent at a right angle toward the 
first centrifugal mass 2 and actuates a friction device 8 which is 
oriented concentric to the axis of rotation 3 approximately radially 
inside the screws 10 to fasten the first centrifugal mass 2 to the 
crankshaft. 
Another feature of the invention resides broadly in the flywheel with two 
centrifugal masses characterized by the fact that the friction device 8 is 
located by a sheet metal part 28 which is fastened by means of the screws 
10 to the first centrifugal mass, and radially inside the diameter formed 
by the screw heads 11, is bent toward the clutch 17 in the form of a tube 
segment 30, and forms a cylindrical seat on the outside diameter. 
Yet another feature of the invention resides broadly in the flywheel with 
two centrifugal masses characterized by the fact that in the radial space 
between the screw heads 11 and the tube segment 30, there is a friction 
ring 31 located on the cylindrical seat, which is axially friction-seated 
in place by a spring 32 which is supported on the end of the tube segment 
30, and which is actuated by areas 26 of the cover-like actuator element 
12. 
Still another feature of the invention resides broadly in the flywheel with 
two centrifugal masses characterized by the fact that the areas 26 are 
engaged in recesses 33 of the friction ring 31, whereby the recesses 33 
are preferably larger in the circumferential direction than the areas 26. 
A further feature of the invention resides broadly in the flywheel with two 
centrifugal masses characterized by the fact that the areas which actuate 
the friction ring 31 are formed by fingers 26 which run approximately 
radially inward. 
Another feature of the invention resides broadly in the flywheel with two 
centrifugal masses characterized by the fact that the cover-like actuator 
element 12 has passage openings 29 for tools used to tighten and loosen 
the screws 10 in the vicinity of the longitudinal axes of the screws 10. 
Yet another feature of the invention resides broadly in the flywheel with 
two centrifugal masses, comprising a first centrifugal mass fastened to 
the crankshaft of an internal combustion engine and defining an axis of 
rotation, a second centrifugal mass which is rotationally mounted on the 
first centrifugal mass by means of a bearing, a torsion damping device 
between the two centrifugal masses with several spring elements 
distributed on the circumference on an intermediate diameter concentric to 
the axis of rotation, at least one friction device between the two 
centrifugal masses, screws on a smaller intermediate diameter parallel to 
the axis of rotation which connect the first centrifugal mass to the 
crankshaft, cover-like actuator elements for the spring elements with 
circumferential control edges which are connected to the second 
centrifugal mass and which are located on both sides of a hub disc with 
radially-projecting arms, a starter and shifting clutch on the side of the 
second centrifugal mass facing away from the first centrifugal mass, which 
clutch is located on the second centrifugal mass with friction surfaces to 
clamp a clutch plate, characterized by the fact that the cover-like 
actuator element 12 facing the starter and shifting clutch 17 is extended 
radially inward and is bent at a right angle toward the first centrifugal 
mass 2 and actuates a friction device 8, that the hub disc 16 which runs 
essentially radially, in the vicinity of the outside diameter of the screw 
heads 11 of the screws 10 is bent at approximately a right angle to the 
first centrifugal mass 2 and forms a bend 36 and is fastened to the first 
centrifugal mass 2, and a friction device 9 is located between the bent 
area and the output-side, cover-like actuator element 12. 
Still another feature of the invention resides broadly in the flywheel with 
two centrifugal masses characterized by the fact that the friction device 
9 is designed to generate the basic friction, with a friction ring 34 
which is concentric to the axis of rotation 3, which is adjacent to the 
bend 36 and is centered there, as well as a spring plate 35 between the 
friction ring 34 and the output-side actuator element 12. 
A further feature of the invention resides broadly in the flywheel with two 
centrifugal masses characterized by the fact that the friction ring 34 has 
an inside diameter which is smaller than the outside diameter of the heads 
11 of the screws 10 and thus prevents the screws 10 from being lost. 
Another feature of the invention resides broadly in the flywheel with two 
centrifugal masses characterized by the fact that the actuator elements 
12, 13 are designed so that they fit tightly around the contour of the 
spring elements 7, at least radially outward, and the control edges are 
formed by separately installed elements 14, 15, and the seal is provided 
radially inwardly between the bend 36 and the friction ring 34, as well as 
between the spring plate 35 and the friction ring 34 or the output-side 
actuator element 12, respectively. 
Yet another feature of the invention resides broadly in the flywheel with 
two centrifugal masses characterized by the fact that the hub disc 16 has 
a bearing point in the area which is bent toward the screw heads 11 for a 
bearing 5 which supports the second centrifugal mass 4. 
Still another feature of the invention resides broadly in the flywheel with 
two centrifugal masses characterized by the fact that the second 
centrifugal mass 4 is mounted on the bearing 5 by means of the cover-like 
actuator element 13 facing the first centrifugal mass 2. 
A further feature of the invention resides broadly in the flywheel with two 
centrifugal masses characterized by the fact that the radially inner area 
of the actuator element 13 is bent toward the first centrifugal mass 2, in 
this area is placed on the bearing 5, axial protection is provided in one 
direction by a collar, and the axial protection is provided in the other 
direction by an extension of one of the elements forming the control edges 
15. 
Another feature of the invention resides broadly in the flywheel with two 
centrifugal masses characterized by the fact that the bearing 5 is 
designed as a roller bearing, with at least one seal on the side facing 
the first centrifugal mass 2. 
Yet another feature of the invention resides broadly in the flywheel with 
two centrifugal masses characterized by the fact that the two actuator 
elements 12, 13 are connected tightly to one another, preferably by 
welding, radially outside the spring elements 7. 
Still another feature of the invention resides broadly in the flywheel with 
two centrifugal masses characterized by the fact that the hub disc 16 is 
bent toward the first centrifugal mass 2 radially inside the arms 37 for 
the actuation of the spring elements 7 by means of a bend 36, the hub disc 
runs radially inward with an additional bend 38, in this area is adjacent 
to the first centrifugal mass 2, and is fastened by the screws 10 together 
with the first centrifugal mass 2 to the crankshaft, and radially inside 
the screw heads 11 is joined in one piece with a tube segment 30 which 
points away from the first centrifugal mass 2. 
A further feature of the invention resides broadly in the flywheel with two 
centrifugal masses characterized by the fact that the bearing for mounting 
the second centrifugal mass 4 is located in the area between the two bends 
36, 38, and a friction ring 31 for the friction device 8 for the load 
friction is located on the tube segment 30 radially inside the screw heads 
11. 
Another feature of the invention resides broadly in the flywheel with two 
centrifugal masses characterized by the fact that the cover-like actuator 
element 12, in addition to the actuation of the friction device 8, 9 is 
connected radially outside the spring elements 7, in an area which runs 
radially, to the second centrifugal mass 4, surrounds the second 
centrifugal mass 4 radially outside its outside diameter, and is designed 
on the side away from the first centrifugal mass 2 for fastening the 
starter/shifter clutch 7. 
The components disclosed in the various publications, disclosed or 
incorporated by reference herein, may be used in the embodiments of the 
present invention, as well as, equivalents thereof. 
Some examples of clutch assemblies and various components associated 
therewith which could possibly utilize the present invention may be 
disclosed in the following U.S. patents: U.S. Pat. No. 4,684,007 to 
Maucher, entitled "Clutch Plate"; U.S. Pat. No. 4,635,780 to Wiggen, 
entitled "Clutch Disc for a Motor Vehicle Friction Clutch"; U.S. Pat. No. 
4,651,857 to Schraut et al., entitled "Clutch Disc Unit for a Motor 
Vehicle Friction Clutch"; U.S. Pat. No. 5,103,688 to Kuhne, entitled 
"Two-mass Flywheel"; and U.S. Pat. No. 4,777,843 to Bopp, entitled 
"Two-mass Flywheel Assembly With Viscous Damping Assembly". 
Additional examples of clutch assemblies and various components associated 
therewith which could utilize the present invention may be disclosed in 
the following U.S. patents: U.S. Pat. No. 5,117,959 entitled "Torsion 
Damping Device in Particular for Automotive Vehicles" to Valeo; U.S. Pat. 
No. 4,763,767 entitled "Torsional Damping Device" to Valeo; U.S. Pat. No. 
4,667,801 entitled "Clutch Disc Arrangement" to Fichtel & Sachs; U.S. Pat. 
No. 5,238,096 entitled "Clutch Plate for a Motor Vehicle Friction CLutch" 
to Fichtel & Sachs; and U.S. Pat. No. 5,016,744 entitled "Clutch Disc for 
a Friction Clutch" to Fichtel & Sachs. 
Some examples of transmissions in which the present invention may be 
incorporated may be disclosed by the following U.S. patents: U.S. Pat. No. 
5,199,316 to Hoffman, entitled "Fully-Synchronized Multiple Speed Manual 
Transmission for Motor Vehicle"; U.S. Pat. No. 4,458,551 to Winter, 
entitled "Manual Transmission"; and U.S. Pat. No. 3,858,460 to Porter et 
al., entitled "Four Speed Manual Transmission and Control". 
Some types of neoprene plastics that could be utilized in accordance with 
the present invention may be or are disclosed in the following U.S. 
patents: U.S. Pat. No. 5,217,778 entitled "Composite Fiber Friction 
Facing" to Raymark Industries; U.S. Pat. No. 5,360,842 entitled 
"Non-asbestos Friction Material" to Akebono; and U.S. Pat. No. 5,281,651 
entitled "Compatibilization of Dissimilar Elastomer Blends Using 
Ethylene/Acrylate/Acrylic Acid Terpolymers" to Arjunan and Kusznir. 
Some examples of two-mass flywheels and the components thereof which may 
incorporate the present invention therein may be disclosed by the 
following U.S. patents: U.S. Pat. No. 5,103,688 to Kuhne, entitled 
"Two-Mass Flywheel"; U.S. Pat. No. 4,777,843 to Bopp, entitled "Two-Mass 
Flywheel Assembly With Viscous Damping Assembly". 
The appended drawings in their entirety, including all dimensions, 
proportions and/or shapes in at least one embodiment of the invention, are 
accurate and to scale and are hereby included by reference into this 
specification. 
All, or substantially all, of the components and methods of the various 
embodiments may be used with at least one embodiment or all of the 
embodiments, if more than one embodiment is described herein. 
All of the patents, patent applications and publications recited herein, 
are hereby incorporated by reference as if set forth in their entirety 
herein. 
The corresponding foreign patent publication applications, namely, Federal 
Republic of Germany Patent Application No. P 44 28 832.8, filed on Aug. 
17, 1994, having inventors Joachim Lindner and Bernhard Schierling, and 
DE-OS P 44 28 832.8 and DE-PS P 44 28 832.8, are hereby incorporated by 
reference as if set forth in their entirety herein. 
The invention as described hereinabove in the context of the preferred 
embodiments is not to be taken as limited to all of the provided details 
thereof, since modifications and variations thereof may be made without 
departing from the spirit and scope of the invention.