Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02859338 2014-08-13
FRICTION CLUTCH SYSTEM
FIELD OF THE INVENTION
[0001] This invention relates generally to a friction clutch system for
mechanically
coupling a power source to a driven system of a vehicle.
BACKGROUND OF TIIE INVENTION
[0002] As shown in FIGURE 1, one conventional type of friction clutch system
10
may be found in an automobile for engaging, disengaging and transmitting
torque from the
engine 12 (i.e., power source) to a transmission 14 (i.e., driven system). By
way of example,
the conventional automotive friction clutch system 10 includes a thrust or
pressure plate 16
mounted within a clutch housing 18 so that the thrust plate 16 cannot rotate
within the
housing 18, but can move axially within the clutch housing. The housing 18 is
mounted to a
counterthrust plate 20. Being weighted, the counterthrust plate is also
commonly used as a
flywheel as well. The flywheel 20 is mounted to and driven by the power source
12, which
may take the form of an internal combustion engine, an electric motor, etc.
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[0003] The pressure plate 16 may be biased or pressed toward the flywheel 20
by
one or more partially compressed Belleville springs, (diaphragms), or coil
springs (not
shown) and may or may not also employ centrifugal clamping force assist (in
the form of bob
weights, not shown) all of which can be mounted within the housing 18. The
assembled
combination of the clutch housing 18, the pressure plate 16, and the
diaphragm/spring is
generally referred to as a pressure plate assembly 22 within the automotive
industry.
[0004] A friction disc assembly 24 is located between the flywheel 20 and the
pressure plate assembly 22. The friction disc assembly 24 includes, in the
illustrated
example, a floater disc 26 sandwiched between two friction discs 28. The
friction discs 28
include friction facings or linings 30, a carrier plate 32 and a splined hub
34. The friction
facings 30 bonded or otherwise, are mechanically connected to the carrier
plate 32. The
carrier plates 32 are coupled by the splined hub 34, which takes the form of
an internally
splined hub, to an externally splined shaft 36 of the driven member 14.
100051 In FIGURE 2, the like components retain the same reference numerals,
but
the friction clutch system 10 includes a different friction disc assembly 40.
As illustrated, the
friction disc assembly 40 includes a floater disc 42 sandwiched between two
friction
discs 44, both having multiple, radially located damper springs 46 for the
purpose of
smoothing clutch engagement and isolating engine vibrations from the
transmission 14 and
driveline (not shown). The damper springs 46 are positioned in a sprung hub
assembly 48
that extends axially.
100061 For greater torque capacity and improved heat dissipation, a friction
clutch
system may incorporate multiple friction discs mounted between the pressure
plate assembly
and the flywheel. For multi-plate clutch designs, the floater or floater plate
may be mounted
to and driven by the flywheel, with a floater being located between adjacent
pair of friction
discs. The pressure plate assembly, flywheel and floater also serve as
friction surfaces for the
friction discs. Because each friction disc assembly typically has two friction
surfaces, a two-
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disc clutch will have four friction surfaces, a three disc clutch will have
six friction surfaces,
and so on.
[0007] The torque capacity of a friction clutch system is defined as the
maximum
amount of torque that can be transferred through thc system while in its fully
engaged state.
Once the clutch torque capacity has been exceeded, torque can be lost through
the
unintentional slipping effect caused between the friction surfaces of the
friction clutch system
components.
[0008] The conventional clutch system of FIGURE 1 includes two solid hubs,
each
with internal splines for engaging the shaft of the transmission, but without
any damper
springs to reduce the spatial envelop and provide a low rotating weight.
However, the lack of
damper springs to smooth clutch engagement and isolate engine vibrations can,
at least
eventually, have a detrimental effect on driveline components. In addition,
clutch
performance and drive-ability of the vehicle may be diminished.
[0009] The conventional, multiple disc clutch system of FIGURE 2 with the two
sprung hub assemblies, both internally splined for engaging the shaft of the
transmission may
help with isolating engine vibrations, but require a greater spatial envelope
and increase the
rotating weight of the system. Current space constraints in various vehicles
would not
provide room for such an arrangement. Consequently, both conventional systems
may be
undesirable for use as a high-performance clutch system
SUMMARY OF THE INVENTION
[0010] A friction clutch system mechanically couples a power source to a
driven
system of a vehicle while providing torsional damping within the system.
[0010a] In one aspect, there is described a friction clutch system comprising:
a first
member defining an axis of rotation; a locator pin extending outwardly from
the first member
parallel to the axis of rotation and offset therefrom; a second member; and a
damper
assembly secured to the second member and slidably engaging the locator pin,
the damper
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assembly configured to simultaneously permit and dampen relative movement
between the
locator pin and the second member in an axial plane perpendicular to the axis
of rotation.
[0010b] The first member may be a flywheel, and the second member may be a
floater.
[0011] In some embodiments, the friction clutch system includes a drive pin
secured to the flywheel and extending outwardly from the flywheel parallel to
the axis of
rotation and offset therefrom. The floater may define a drive pin receiver
slidably engaging
the drive pin.
[0012] In some embodiments, the locator pin is a one of a plurality of locator
pins
distributed uniformly about the axis of rotation. Likewise, the damper
assembly is one of a
plurality of damper assemblies, each damper assembly engaging a locator pin of
the plurality
of locator pins.
[0013] In some embodiments, the damper assembly includes a bearing member
slidably engaging the locator pin and a bearing receiver configured to
slidably engage the
bearing member effective to dampen vibration of the bearing member relative to
the bearing
receiver. In some embodiments, the bearing member defines a bearing aperture
having the
locator pin inserted therethrough, the bearing aperture being sized to prevent
circumferential
and radial movement of the locator pin relative to the bearing member.
[0014] In some embodiments, the bearing receiver includes an upper plate
defining
an upper aperture and a lower plate defining a lower aperture, the locator pin
being inserted
through the upper and lower apertures and the bearing member being positioned
between the
upper and lower plates. The upper and lower apertures may be larger than the
bearing
aperture.
[0015] In some embodiments, a retention plate is secured to the floater having
the
upper and lower plates and bearing member captured between the retention plate
and the
floater. The retention member may define a retention aperture having the
locator pin inserted
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therethrough. The retention aperture may also be larger than the hearing
aperture. In some
embodiments, a biasing member positioned between the retention member and thc
lower
plate, the biasing member urging the lower plate against the bearing member.
[0016] In some embodiments, a drive pin is secured to the flywheel and extends
outwardly from the flywheel parallel to the axis of rotation and offset
therefrom. The floater
may define a drive pin receiver slidably engaging the drive pin. In some
embodiments, the
drive pin receiver permits a first amount of angular movement of the drive pin
about the axis
of rotation within the drive pin receiver and the bearing aperture permits a
second amount of
angular movement of the locator pin about the axis of rotation within the
bearing aperture,
the second amount being less than the first amount. For example, the second
amount may be
less than 1 percent of the first amount.
[0017] In some embodiments, the upper aperture, lower aperture, and retention
aperture each permit at least a third amount of angular motion of the locator
pin therein about
the axis of rotation. The third amount may be greater than or equal to the
first amount.
[0017a] In a further aspect, there is described a friction clutch system
comprising: a
flywheel defining an axis of rotation; a locator pin extending outwardly from
the flywheel
parallel to the axis of rotation and offset therefrom; a floater; and one or
more friction plates
positioned facing the floater; a splined shaft slidably engaging at least one
of the one or more
friction plates, the splined shaft being coupled to a transmission; a clutch
actuator engaging
the one or more friction plates for selectively urging the friction plates
into engagetnent with
the floater; and a damper assembly secured to the floater and slidably
engaging the locator
pin, the damper assembly configured to simultaneously dampen relative movement
between
the locator pin and the floater and permit movement of the locator pin in
axial plane
perpendicular to the axis of rotation.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Preferred and alternative embodiments of the present invention are
described
in detail below with reference to the following drawings.
[0019] FIGURE 1 is an exploded, schematic view of a prior-art friction clutch
system
having friction disc assemblies each with solid hubs coupled to a splined
shaft of a driven
member;
[0020] FIGURE 2 is an exploded, schematic view of a prior-art friction clutch
system
having friction disc assemblies each with damping springs located in hubs
coupled to a
splined shaft of a driven member;
[0021] FIGURE 3A is an exploded, schematic view of a friction clutch system
having
a first friction disc assembly with protuberances to directly engage a second
friction disc
assembly according to an embodiment of the present invention;
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[0022] FIGURE 3B is schematic, side elevational view of the first friction
disc of
FIGURE 3A with protuberances according to an embodiment of the present
invention;
100231 FIGURE 3C is schematic, side elevational view of the second friction
disc of
FIGURE 3A with openings according to an embodiment of the present invention;
100241 FIGURE 4 is a perspective, exploded, partially cut-away view of a
friction
clutch system having a first friction disc assembly with protuberances to
directly engage a
second friction disc assembly according to an embodiment of the present
invention;
[0025] FIGURE 5 is a an exploded, schematic view of a friction clutch system
having
a first friction disc assembly positioned adjacent to a driven member (e.g.,
pressure plate
assembly) and a second friction disc assembly positioned adjacent to a power
source
(e.g., flywheel) according to another embodiment of the present invention;
100261 FIGURE 6A is a top, plan view of a friction clutch system having a
floater
resiliently coupled to a flywheel with a plurality of resilient coupling
assemblies according to
an embodiment of the present invention;
100271 FIGURE 6B is a top, plan view of one of the resilient a spring portion
and clip
portion from one of the resilient coupling assemblies of FIGURE 6A;
100281 FIGURE 6C is a top, plan view of a spring portion from one of the
resilient
coupling assemblies of FIGURE 6A;
100291 FIGURE 7 is a schematic side view of the friction clutch system of
FIGURE 6A;
[0030] FIGURES 8A, 8C and 9 are perspective views of a friction clutch system
having spring-loaded members mounted to the clutch pressure plate according to
another
embodiment of the present invention;
100311 FIGURES 8B, 8D, 8E, 8F and 8G are perspective views of a friction
clutch
system having spring-loaded detent members mounted to the flywheel according
to another
embodiment of the present invention;
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[0032] FIGURE 10 is an isometric exploded view of a floater plate and flywheel
having a damping system in accordance with an embodiment of the present
invention;
[0033] FIGURE 11 is a partial cross-sectional view of the damping system of
FIGURE 10; and
[0034] FIGURE 12 is a partial cross-sectional view of an alternative
configuration of
the damping system of FIGURE 10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] The present invention generally relates, but is not limited, to
friction clutch
system for mechanically coupling a power source to a driven system of a
vehicle. In at least
one embodiment, the present invention combines a spring-damped, splined hub
with one or
more secondary friction discs. The hub includes axially extending
protuberances that engage
radial slots located in the secondary friction disc. Advantageously, the
friction clutch system
described herein may allow for torsional vibration damping while reducing the
rotational
mass of the system. Further, the friction clutch system may provide a more
compact and
simplified installation.
[0036] FIGURE 3A shows an exploded, schematic view of a friction clutch
system 100 for engaging, disengaging and transmitting torque from a power
source 102 (e.g.,
engine) to a driven member 104 (e.g., transmission). Similar to the
conventional friction
clutch systems described above, the illustrated friction clutch system 100
includes a pressure
plate assembly 106 comprising a pressure plate 108 mounted within a clutch
housing 110,
which in turn is mounted to a counterthrust plate or flywheel 112.
[0037] In the illustrated embodiment, the pressure plate assembly 106 includes
a
spring or springs that provide the primary engagement force to a friction disc
assembly 114,
vvhich may include multiple (two or more) friction discs 116, 118 with a
floater plate 120
located therebetween. The floater plate 120 may take the form of the floater
plates previously
described.
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[0038] Of the two illustrated friction discs 116, 118, only first disc 116
includes a hub
assembly 122 mounted to a driven shaft 124. The second disc 118 does not have
a hub
assembly (e.g., sprung hub) and is not mounted to the driven shaft 124, but
instead engages
the first disc 116 as will be described in detail below. Such a configuration
may
advantageously provide a lighter weight system having a lower rotational
inertia while also
being more spatially compact than previous systems in which each friction disc
included its
own hub assembly independently splined to the driven shaft. The space
requirements are
reduced due to having fewer sprung splined hub assemblies than friction discs.
One of the
drawbacks of the conventional assembly shown in FIGURE 2 was that the amount
of space
required to have a sprung hub on each friction disc exceeded the allowable
design spatial
envelope between the pressure plate assembly and flywheel. Thus, to fit such
an assembly the
springs in the hub assembly would have to be made quite small, making them
more difficult
to install, harder to retain and less robust in view of the spring forces
needed. Another
possible advantage of the friction clutch system 100 is that it may replace
stock clutch
systems within the space envelope provided for the stock clutch system.
[0039] Referring now to FIGURES 3 and 4, the first disc 116 includes the hub
assembly 122 and friction facing and/or a plurality of friction pads 126
mounted
circumferentially onto a disc body 128. The hub assembly 122 includes an
internal splined
portion 130, a plurality of damping springs 132, and a plurality of
protuberances 134
extending from a hub assembly cover 136. The damping springs 132 may take the
form of
torsional damping springs. The protuberances 134 may take the form of pins or
dowels,
which may be cylindrical or have another type of cross-sectional shape. The
protuberances 134 extend in an axial direction as indicated by arrow 138
(FIGURE 3A).
[0040] The second disc 118 includes a friction facing and/or a plurality of
friction
pads 140 coupled to a central member 142. A plurality of openings 144 are
machined or
otherwise formed into the central member 142. The openings 144 may take the
form of radial
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slots or notches extending from an inner edge 146 of the central member 142.
In addition, the
openings 144 are configured to receivably and directly engage the
protuberances 134 of the
first disc 116. This engagement prevents the discs 116, 118 from rotating
relative to one
another, but will permit independent axial movement of the secondary friction
disc(s) within
the given design range. As best seen in FIGURE 4, the openings 144 preferably
have a shape
that complementarily corresponds to the cross-sectional shape of the
protuberances 134. For
example, if the protuberances 134 are cylindrical then the openings will be
circular as well.
Alternatively radial slots could receive protuberances of various
configurations. Further the
openings 144 are sized and aligned to accurately receive the protuberances
134.
[0041] FIGURE 5 shows a friction clutch system 200 in which a first disc 202
with a
hub assembly 204 and protuberances 206 is positioned adjacent to a pressure
plate
assembly 208. A second disc 210 with openings (not shown) to receive the
protuberances 206 is positioned adjacent to a flywheel 212. In comparing
FIGURE 5 to
FIGURE 3, the locations of the first and second discs have been switched.
Consequently, the
first disc 202 may be on the driven side proximate the driven member 214
(e.g.,
transmission) while the second disc 210 may be on the driving or power side
proximate the
power source 216 (e.g, engine).
[0042] FIGURES 6A and 6B show a friction clutch system 300 with a floater 302
resiliently coupled to a flywheel 304 by means of pins 305 or lugs attached to
the flywheel
304. This engagement between the flywheel 304 and the floater 302 prevents
independent
rotation relative to one another, but will allow independent axial movement of
the floater
plate 302 relative to the flywheel 304 In the illustrated embodiment, the
resilient coupling is
achieved with a resilient coupling assembly 306, which as best shown in FIGURE
6B takes
the form of a leaf spring 308 fixed to a clip 310. The leaf spring 308 may
include a central
arcuate portion 312 fixed to the clip 310. Symmetric arms 314 extend
respectively from the
central arcuate portion 312. Both arms 314 include a contact surface 316 for
contacting the
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floater 302 along a radial line of action 315 relative to a center point 317
of the floater 302.
However, the resilient coupling assembly 306 may take other forms such as a
compression
spring or a spring-loaded detent. The free ends of these springs or detents
308 may be
weighted or manufactured in a manner that will allow a centrifugal force,
generally directed
radially outward as shown by arrow 319, to overcome or negate the spring
force, generally
directed radially inward as shown by directional arrow 321, acting upon the
floater 302. This
design allows for quiet clutch operation at low engine revolutions per minute
(RPM) while
improving high RPM gear changes.
[0043] FIGURE 6C shows the leaf spring 308 with a number of reference
dimensions
to generally indicate that the leaf spring 308 may be designed for a variety
of situations to
provide a stiffer or softer spring rate. By way of example, a shackle angle
318 that
determines the angle of the eyes 320 relative to a datum line 322 may be
varied to increase or
decrease spring rate. A vertical line 324 indicates a ninety-degree (90 )
shackle angle. In
addition, a radius 326 of the central arcuate portion 312 may be modified to
change the
spring rate of the leaf spring 308. In the illustrated embodiment, the radius
defines a
reference circle 328. However, it is appreciated that the central arcuate
portion 312 may be
non-circular, for example parabolic or have some other complex curvature.
[0044] Referring back to FIGURE 6A, the friction clutch system 300 includes
three
resilient coupling assemblies 306, which corresponds to six contact locations
because each
assembly 306 includes two arms 314 (FIGURE 613). However, it is appreciated
that a fewer
or greater number of resilient coupling assemblies 306 may be employed
depending on the
size, loading, and other aspects of the friction clutch system 300. The
resilient coupling
assemblies 306 preferably in combination with drive pin receivers 330, e.g.
gaps 330, permit
the floater 302 to operate relative to the flywheel 304 while minimizing, if
not eliminating,
audible sounds that would ordinarily come from the floater 302 vibrating or
"rattling"
relativeto the flywheel 304.
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[0045] FIGURE 7 schematically shows the floater 302 coupled to the flywheel
304
using the resilient coupling assembly 306. The clip 310 takes the form of a
bent metal
clip mechanically attached to the flywheel 304 with a fastener 322. The spring
force of the
clip 310 is generally directed as indicated by arrow 334.
[0046] FIGURES 8A, 8C and 9 show another embodiment of a friction clutch
system 400 having a floater 402 resiliently coupled to a pressure plate
assembly 404 with a
resilient coupling assembly 406. In the illustrated embodiment, the assembly
406 takes the
form of a spring-loaded mechanism that is compression loaded between the
floater 402 and
the pressure plate assembly 404. The spring-loaded mechanism 406 is oriented
along a radial
line of action 408 extending from a central point 410 of the floater 402 or
pressure plate 404
toward the spring-loaded mechanism 406. Alternatively stated, the spring-
loaded
mechanism 406 is attached to the pressure plate 404 and oriented to absorb
kinetic energy
from the floater 402 in a radial direction 408, and in which a spring force of
the
mechanism 406 is directed radially inward as indicated by arrow 412 to react a
centrifugal
force directed radially outward as indicated by arrow 414. In the illustrated
embodiment, the
assembly 406 takes the form of a semi-spherical member in contact engagement
with a pin as
best shown in FIGURE 8C.
[0047] FIGURE 8B and 8D-8F show the friction clutch system 400 with the
flywheel 404engaged with the floater 402 using a detent mechanism 406. In the
illustrated
embodiment, the detent mechanism 406 is adjustably received in a boss or lug
416 coupled to
the flywheel 404. The mechanism 406 includes an externally threaded body 418
that permits
adjustment relative to the boss 416 and an end cap 420 to secure the mechanism
406 once
adequately adjustcd.
[0048] Referring specifically to FIGURES 8E-8G, the detent mechanism 406
includes the threaded body 418 coupled to a detent plunger 422. A collar 424
may be coupled
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to an end portion of the threaded body 418 to provide a tapered transition
from the threaded
body 418 to the detent plunger 422.
100491 Referring specifically to FIGURES 8F and 8G, the mechanism 406 includes
a
biasing member 426 located within the threaded body 418. The biasing member
426 may
take the form of a coil or compression spring having one end portion seated
against a back
wall of the threaded body 418 and an opposite end portion seated against the
plunger 422.
FIGURE 8F shows the biasing member 426 in an extended position such that a tip
of the
plunger 422 has been moved away from the threaded body 418; whereas FIGURE 8G
shows
the biasing member in a compressed position.
100501 In the illustrated embodiments, the resilient coupling between the
flywheel 404 and the floater 402 is achieved with a detent spring-loaded
mechanism 406.
FIGURE 8B and 8D best show the detent spring-loaded mechanism 406 is mounted
to the
flywheel 404 by threaded means within machined or otherwise permanently
attached
mounting lugs 416.
[00511 FIGURE 8E, 8F and 8G best shows the body of the detent spring-loaded
mechanism 424 contains external threads 418 in which directly engage the
internal threads
(not shown) contained within the flywheel mounting lug 416 and allows for
threaded lock
nut 420 to prevent unintended movement of the detent mechanism 406 in
relationship to the
mounting lug 416. As best shown in FIGURES 8F and 8G the spring-loaded detent
pin 422 is
allowed liner movement within the mechanism body 424 by compressing detent
spring 426.
[00521 FIGURE 8F is a cut-a-way view that shows the detent spring 426 fully
extended within the detent body 424. FIGURE 8G is a cut-a-way view that shows
the detent
spring 426 partially compressed within the detent body 424. By means of the
external body
threads 418 (FIGURE 8E) and internal threads (not shown) contained within the
flywheel
detent mounting lugs 416 allows for varying the amount of spring compression
thus allowing
easy spring force adjustment during manufacture and/or by the end user for
individual
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application optimization. Referring back to FIGURE 8B, the detent pins 422
(shown in
FIGURES 8E, 8F and 8G) can be weighted or manufactured in a manner such that
will allow
centrifugal force, generally directed outward as shown by arrow 414, to
overcome or negate
the spring force as applied by detent spring 426 (shown in FIGURES 8F and 8G),
force
applied generally directed as shown by directional arrow 412 and acting
directly upon the
floater 402. This design also allows for quiet clutch operation at low engine
revolutions per
minute (RPM) while improving high RPM gear changes.
100531 Referring to FIGURE 10, in some embodiments, noise caused by a floater
302
may be reduced by means of damping assemblies 500 coupling the floater 302 to
the
flywheel 304. The illustrated damping assemblies 500 may be used in
combination with
son-te or all of the embodiments of a friction clutch system disclosed
hereinabove.
100541 The damping assembly 500 may engage a locator pin 502 secured to the
flywheel 304 and extending outwardly therefrom parallel to an axis of rotation
of the
flywheel 304 and offset therefrom. The locator pins 502 may take the place of
the drive
pins 305 disclosed herein, but are preferably used in combination with drive
pins 305. The
damping assembly 500 may include a bearing plate or washer 504 that snugly
engages the
locator pin 502. The bearing washer 504 may be engaged by a bearing receiver
operable to
permit movement of the bearing plate 504 in response to vibration of the
floater 302 relative
to the locator pin as well as damp such movement.
100551 In the illustrated embodiment, the bearing receiver is formed by an
upper
plate 506 and a lower plate 508 positioned above and below the bearing washer.
Upper and
lower plates 506, 508 preferably take the form of metal washers. A biasing
member 510 may
engage one or both of the upper plate 506 and lower plate 508 effective to
urge one or both
of the upper plate 506 and lower plate 508 against the bearing plate 504. The
engagement of
the upper plate 506 and lower plate 508 with the bearing plate 504 provides
friction force that
resists movement of the bearing plate 504 thereby damping vibration of the
floater 302. In
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the illustrated embodiment, the bearing plate 504, upper plate 506, and lower
plate 508 are
round washers. However, any shape, including rectangular, may be adequate to
implement a
bearing assembly 500. The biasing member 510 may be a coil spring, leaf
spring, spring
washer (such as a wavy washer), a washer formed of a resilient material (e.g.,
rubber or
polymer), or some other resilient member.
[0056] In some embodiments, the bearing plate 504 includes a material that is
able to
bear the sliding motion relative to the upper and lower plates 506, 508 for a
large number of
cycles without failing. For example, the bearing plate 504 may be formed of,
include, or be
coated with, a lubricating material such as OiliteTm or some other solid
lubricant such as
molybdenum disulfide, tungsten disulfide, polytetrafluoroethylene, or like
substance. In
other embodiments, surfaces of the upper and lower plates 506, 508 engaging
the bearing
plate 504 additionally or alternatively include a similar solid lubricant or
lubricating material.
[0057] A retention plate 512 may retain the bearing plate 504, upper plate
506, lower
plate 508, and biasing member 510 in engagement with the floater 302. For
example,
rivets 514 may secure the retention plate 512 to the floater 302 having the
bearing plate 504,
upper plate 506, lower plate 508, and biasing member 510 captured between the
retention
plate 512 and the floater 312. In some embodiments, the retention plate 512
may also
function as a biasing member urging the upper and lower plates 506, 508 into
engagement
with the bearing plate 504. For example, the retention plate 512 may be bowed,
bent, have a
concave shape, or otherwise be configured to provide a biasing force upon
being secured to
the floater 302.
[00581 In some embodiments, the upper plate 506 may be replaced with a portion
of
the floater 302 engaging the bearing plate 504 and/or the functionality of the
lower plate 508
may be provided by the retention plate 512 or biasing member 510 engaging the
bearing
plate 504 directly. Likewise, the functionality of the biasing member 510 may
be replaced
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by biasing force exerted by the retention plate 512 and the biasing member 510
may be
omitted.
[0059] Referring to FIGURE 11, the bearing plate 504 may define an aperture
516
having the locator pin 502 inserted therethrough. Thc aperture 516 may have a
size, e.g.
diameter, that is large enough to permit sliding of the locator pin 502
without significant
resistance but small enough to inhibit lateral movement of the locator pin 502
within the
aperture 516, e.g. perpendicular to the axis of rotation of the flywheel 304.
100601 The upper plate 506 and lower plate 508 may likewise define
apertures 518, 520. The apertures 518, 520 may have sizes, e.g. diameters,
that are larger
than that of the aperture 516. In this manner, the locator pin 502 is
permitted to move within
the apertures 518, 520 but not the aperture 516 thereby causing the bearing
plate 504 to slide
between the upper plate 506 and lower plate 508 in response to vibrations of
the locator
pin 502.
[0061] In the illustrated embodiment, the retention plate 512 defines an
aperture 522
through which the locator pin 502 passes. The aperture 522 may likewise be
larger, e.g. have
a larger diameter, then the aperture 516. In some embodiments, the locator pin
502 also
passes partially or completely through the floater 302, which may define an
aperture 524 for
receiving the locator pin 502. The aperture 524 may have a size, e.g.
diameter, that is also
larger than the aperture 516 such that the locator pin 502 is able to move
within the
aperture 524.
[00621 In the embodiment of FIGURE 11, some or all of the bearing plate 504,
upper
plate 506, lower plate 508, and biasing member 510 are positioned within a
recess 526
defined by the floater. For example, the retention plate 512 may be secured
over an opening
of the recess securing the bearing plate 504, upper plate 506, lower plate
508, and biasing
member 510 within the recess. As noted above, the bearing plate 504 may be
permitted to
slide between the upper and lower plates 506, 508. Accordingly, the recess 526
may be
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CA 02859338 2014-08-13
larger than the bearing plate 504 in at least one dimension to permit movement
of the bearing
plate 504 in at least that direction. For example, the bearing plate 504 may
be a washer with
a radius smaller than a radius of the recess 526. A depth of the recess 526,
e.g. parallel to the
axis of rotation of the floater 302 and flywheel 304, may be such that upon
securement of the
retention plate 512, the biasing member is not completely compressed, e.g. no
longer capable
of further compression due to elastic deformation.
10063J As noted above, the flywheel 304 may have one or more drive pins 305
that
engage the floater 302 in order to transfer toque from the flywheel 304 to the
floater 302.
For example, the floater 302 may include drive pin receivers 330 embodied as
notches or
apertures defined near the perimeter of the floater 302. In some embodiments,
a gap exists
between the drive pin receiver 330 and the drive pin 305. For example, a first
amount of
movement, including one or both of angular and radial movement relative to the
axis of
rotation of the floater 302 and flywheel 304, may be permitted between the
drive pins 305
and the receivers 330 absent any other restraints on relative movement of the
floater 302 and
flywheel 304. In some embodiments, each locator pin 502 may be located
adjacent a drive
pin 305, e.g. within 30 degrees, preferably 20 degrees, and more preferably
within
degrees, as measured about the axis of rotation of the floater 302 and
flywheel 304.
100641 In some embodiments, a second amount of movement, including one or both
of angular and radial movement relative to the axis of rotation of the floater
302 and
flywheel, 304 is permitted between the locator pin 502 and the aperture 516 in
the bearing
plate 504 due to the size of the aperture 516 relative to the locator pin 502
absent other
restraints on relative movement. The second amount is preferably smaller than
the first
amount. In this manner, typical movements of the drive pin 305 relative to the
drive pin
receiver 330 will be resisted by friction between the bearing plate 504 and
the upper and
lower plates 506, 508. For example, the second amount may be less than 10%,
preferably
less than 5%, and more preferably less than 1% of the first amount.
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100651 As noted above, the apertures 518, 520 of the upper and lower plates
506, 508,
the aperture 522 of the retention plate 512, and the aperture 524 in the
floater 524 may all
receive the locator pin 502 inserted therethrough. As also noted above, all of
these apertures
may be larger than the aperture 516 of the bearing plate 504. In some
embodiments, it is not
desired to load the locator pin 502. Accordingly, each of these apertures may
allow at least a
third amount of movement, including one or both of angular and radial movement
relative to
the axis of rotation of the floater 302 and flywheel 304, of the locator pin
502 within the each
aperture absent other constraints on relative movement. The third amount may
be greater
than or equal to the first amount, preferably greater. In this manner,
relative movement of
the flywheel 304 and floater 302 in response to application of torque will be
arrested by
engagement of the drive pin 305 with the drive pin receiver 330 rather than by
loading the
locator pin 502.
[00661 Likewise, as noted above, the recess 526 may be larger than the bearing
plate 504. For example, a fourth amount of movement, including one or both of
angular and
radial movement relative to the axis of rotation of the floater 302 and
flywheel 304, of the
bearing plate 504 within the recess 526 may be permitted absent other
constraints on
movement of the bearing plate 504 within the recess 526. In this manner,
permissible
movement of the drive pin 305 within the receiver 330 will not be constrained
due to the
bearing plate 504 abutting the recess 526.
[00671 The locator pin 502 may secure to the flywheel 304 by means of a
threaded
portion 528. In some embodiments, a nut 530 may also engage the threaded
portion 528 in
order to ensure that threads engaged with the flywheel 304 are sufficiently
tensioned to retain
the locator pin 502. Other means of securement are also possible, including
welds or other
removable and non-removable fastening means. In some embodiments, the locator
pin and
nut 530 may secure within a recess 532 defined by the flywheel 304 such that
the nut 530
does not protrude outside an opening of the recess 532.
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10068] Various alternative configurations and mounting schemes may be used to
secure the damping assembly 500 to the floater 302. For example, referring to
FIGURE 12,
in somc embodiments, the recess 526 may be omitted or sized such that the
damping
assembly 500 protrudes from a face of the floater 302.
100691 Furthermore, although the locator pin 502 is secured to the flywheel
304 and
the damping assembly 500 is secured to the floater 302 in the illustrated
embodiment, this
configuration can be reversed in some embodiments. Also, although the damping
assembly 500 is shown interposed between the floater 302 and the flywheel 304,
in some
embodiments, the damping assembly 500 may be positioned having the floater 302
positioned between it and the flywheel 304.
100701 While the preferred embodiments of the invention have been illustrated
and
described, as noted above, many changes can be made without departing from the
scope of
the invention. Accordingly, the scope of the invention is not limited by the
disclosure of the
preferred embodiments. Instead, the invention should be determined entirely by
reference to
the claims that follow.
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