Note: Descriptions are shown in the official language in which they were submitted.
077~28-BB ~1~5 ~42
The present invention rela~es tO a torsional vibra~ion
damper assembly for use in a torsion coupling between a pair
of axially aligned shafts, in a clutch for a manual trans-
mission or in a lock-up clutch for a torque converter of an
automatic transmission.
Vibration in a vehicle drive train has been a long-
standing problem due to the sudden shock of engagement o
the clutch disc in a vehicle clutch for a ~anual trans-
mission and to the torque fluctuations occurring in an
internal combustion engine. The use of a vibration damper
has been long accept~d as a way of counteracting these tor-
sional vi.brations rom the vehicle engine which would other-
wise cause undesirable characteristics, e.g., impact loads,
pulsations, noises, etc., in the transmission and driveline
during operation o~ the vehicle.
In an automatic transmission having a constant slipping
device, torsional vibrations are not a problem unless a
lock-up clutch is utilized to provide a direct drive in
order to enhance fuel economy. Without the lock-up clut h,
the vibrations axe absorbed hydraulically; but when a
torque eonverter is locked in direct drive, a vibration
d~mper is required to eIiminate any dis~urbance resulting
from torsional vibration. Likewise, the vibra~ion damper`
assembly is convenient or use as a fle~ible co~pling
between an input shaft and output shaft where flexibility is
required. The present inven~ion provides a novel vibration
damper assembly that will be use~ul in all of these various -~
applications.
The present invention comprehends a novel vibration
damper assembly which provides a relatively low rate, high
amplitude deflection between the torque input and output
elements.
According to one aspec-t of the present invention,
there is provided a vibration damper assembly for trans-
mitting torque between driving and driven elements, the
assembly including an input member operatively associated
with torque input means, and a hub assembly operatively
connected to torque output means. A housing encompasses
the hub assembly and floating spacers are provided within
the housing. Resilient means are provided in the housing
between the spacers, and the hub assembly includes a pair
of oppositely disposed arms adapted to engage the resilient
means. A pair of drive members is secured to the input
member and extend into the housing into the path of and
engaging the resilient means.
The assembly of a specific embodiment o~ the
invention includes mounting means operatively connected to
a torque input, drive members on the mounting means, a hub
barrel and drive plates connected together and operatively
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connected to the output, a plurality of floatiny spacers,
and resilient spring means positioned in the path of the
drive members, floating spacers and drive plates to provide
a resilient connection between the mounting means and the
hub.
A specific embodiment of the present invention
also comprehends a novel vibration damper assembly providing
an extended arc of deflection between the driving and driven
members. The hub is secured to a dish-shaped cover plate
which has a generally flat base and an annular depending
flange or side. The interior surface of the flange provides
a guiding surface for the floating spacers each of which
contains a roller contacting the guiding surface. The
resilient springs contact converging sides of the wedge-
shaped spacers.
A specific embodiment of the present invention
further comprehends a novel vibration damper assembly wherein
the resilient springs are arranged into two groups acting
in parallel, with each group comprising several spring sets
of concentric springs acting in series.
Further objects of the present invention are to
provide a construction of maximum simplicity, efficiency,
economy
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077028-BB
and ease of assembly and operation, and such further objects,
advantages and capabilities as will later more fully appear
and are inherently possessed thereby.
In the accompanying drawings:
Figure 1 is a rear elevational view, partially in cross
section, of ~he vibration damper assembly of the present
invention.
Figure 2 is a vertical cross sectional view of the
vibration damper assembly taken on th~ line 2-2 of Figure 1.
Figure 3 is a partial cross sectional view taken on the
line 3-3 of Figure 1.
Figure 4 is a cross sectional view taken on the irregular
line 4-4 of Figure 2.
Figure 5 is a cross sectional view taken on the line 5-
5 of Figure 4.
Figure 6 is an exploded perspective view of the vibration
damper without the springs and spacers.
Figure 7 is an enlarged exploded perspective view of a
floating spacer.
Referring more particularly to the disclosure in the
drawings wherein is shown an illustrative embodiment of the
present in~ention, Figures 1 and 2 disclos~ a vibration
damper assembly 10 for connection of driving and driven
members (not shown) wherein the assembly can be utiliz d as
a 1exible connection be~ween a pair of axially aligned
shafts, as a lockup clutch in a torque converter for an
automatic transmlssion, or as a clutch in a manual trans-
mission. The present assembly includes a driving member 11,
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which m~y be a clutch friction plate or may be secured to a
flywheel or driving flange of a shaft, having a central
opening 12 defined by an annular flange 13.
Mounted on the member 11 by rivets 14 are a pair of
oppositely disposed drive tangs 15; each tang having an
arcuate base 16 with openings 17 for the rivets, an an-
gularly offset portion 18 and a generally triangular end 19
projecting into a retaining cover plate 21. The cover plate
21 includes a generally flat base portion 22 having a central
opening Z3 and a plurality of openings 24 surrounding open-
ing 23, and a depending skirt or flange 25 joined to the
flat portion 22 by a curved portion 26 and terminating in a
radially extending rim 27. A pair of oppositely disposed
elongated slots 28, 28 are o~med in the flange 25 to
receive the drive tangs 15; each slot having a central enlarged
portion 29 and a narrowed extension 30 at each end of portion
29.
Within the cover plat~ 21 are mounted a first an~ular
barrel hub 31 having a central opening 32 Yplined at 33 and
a plurality of circumferentially spaced openings 34 around
the central opening, a second annular barrel hub 35 also
ha~ing a central opening 36 splined at 37 and circumferen-
tially spaced openings 38 therearound. A pair of substan-
tially identical drive plates 39, 39' are located with one
plate 39 located between the barrel hubs 31, 35 and the
second plate 39' position~d behind the hub 35 away from the
cover plate base portion 22. Each drive pla~e 39, 39'
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includes an annular body 41, 41' having a central opening
42, 42', a plurality of circumferentially spaced openings
43, 43' therearound and a pair of oppositely disposed out-
wardly extending arms 44, 44', each arm having outwardly
diverging edges 45, 45'.
A plurality of rivets 46 extend through the aligned
openings 24, 34, 43, 38 and 43' of the cover plate 21,
barrel hub 31, drive plate 39, barrel hub 35 and dri~e plate
39', respectively, to retain the parts together and form a
unitary cover plate assembly. An annular cpace 47 is ormed
between ~he cover plate flange 25 and the barrel hubs 31, 35
to receive a plurality of damper spring spacers 48, each
spacer being in the form of a generally triangular block
having flat sides 49 converging away from a generally flat
base 50, an inclined end 51 and a curved end surface 52
generally conformable with the curved portion 26 of the
cover plate. A passage 53 extends through the block ad-
jacent the base 50 and has a counterbored portion 54 opening
into the end surface 51 and intersecting thP flat base 50 to
provide an elongated slot 55, as se~n in Figure 7. A shaft
56 has an enlarged head 57 at one end and a reduced shank 5
at the opposite end adapted to be received in the passage
53. A bushing 5g is rotatably mounted on the sha~t 56 and
is receiv~d in the counterbored portion 54 to partially
extend through the slot 55.
Aq shown in Figures 1, 3 and 4, the bushing 59 extends
beyond the base 50 of a spacer 48 to engage the interior
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surface 60 of the cover plate flange 25 and provide a roller
bearing action for the spacer. As seen in Figure 1, two
spacers 48, 48 are positioned between the opposite arms 44,
44' of the drive plates 39, 39' to form therewith three
spring pockets to receive damper springs 61, 62, 61', 62',
and 61", 62". The springs are concentric with a pair of
springs in each pocket. All three pairs of springs seen in
Figure l may be of the same rates or the rates of the pairs
may vary depending on ~he desired characteristics of the
damper. Although two springs are shown for each pocket, a
single spring or three or more concentric springs may be
utilized depending on the desired conditions of use.
Figure 1 discloses three pairs o~ springs on one side
of the centerline d~noted as line 2-2 to form one group of
springs, with a second gro~p of springs being loca~ed on the
opposite side of the centerline 2-2. The two groups of
springs act in parallel and have additive loads, with the
sets of springs in each group acting in series with the
loads not being additive. The rates of the various pairs o~
springs may either be equal or have varying rates, with
springs 61, 62 having the lowes~ rate of compression, the
5prings 61', 62' having an intermediate ra~e, and the springs
61", 62" located between the spacers 48, 48 having the
highest spring rate. Iden~ical springs are provided in the
diametrically opposite pockets as shown in Figure 4.
Considering operation o~ the vibration damper assembly
10, the two drive tangs 15 transmi~ torque from the driving
member 11 through the springs 61, 62, 61', 62' and 61", 62"
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and spacers 48 to the drive plates 39, 39' and barrel hubs
31, 35; the splines 33 and 37 adapted to rereive the splined
end of a driven shaft (not shown) leading to a transmission
or other device. As shown in Figure 1, as the driving
member 11 rotates in either direction, the tangs 15 move in
the slots 28 to compress the lowest rate springs 61, 62
between the tangs 15 and the first spacers 48. The springs
61', 62' and 61", 62" will also be compressed but to a
lesser degree as the spacers 48 move on the bushings 59
relativ~ to the cover plate 21. As the torque is increased,
the springs 61, 62 will be compressed to their solid height,
with the springs 61', 62' being compressed more and springs
61", 62" yieldably transmitting torque. If both springs 61,
62 and 61', 62' are compressed to their solid heights,
springs 61't, 6~" having the highest spring rate will still
yieldably transmit torque. If the spring rates of the
spring sets are identical, the application of input torque
will cau~e compression of all springs 61, 62, 61', 62' and
61" and 62" equally.
; This vibration damper assembly will provide a greater
deflection angle than prior conventional d~mper assemblies.
The angled sides 49, 49 of the spacers 48 react to the
spring orce causing the spacers to be urged outwardly and
provide frictional contact between the bushings and the
interior surface 60 of the cover plate. Although described
with one arrangement of spring rates for each group, the
deflection characteristic for the damper may be varied
depending on the choice of springs. The damper assembly is
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suitable for use in a variety of automotive or industrial
torsional vibration damper applications requiring a low
spring rate and high deflection amplitude characteristic.
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