U.S. patent application number 15/150921 was filed with the patent office on 2016-09-01 for torsional compensator.
The applicant listed for this patent is Dana Limited. Invention is credited to Stijn Goossens, Mark R.J. Versteyhe.
Application Number | 20160252155 15/150921 |
Document ID | / |
Family ID | 50686116 |
Filed Date | 2016-09-01 |
United States Patent
Application |
20160252155 |
Kind Code |
A1 |
Versteyhe; Mark R.J. ; et
al. |
September 1, 2016 |
TORSIONAL COMPENSATOR
Abstract
A parallel, torque additive torsional compensating device for an
internal combustion engine is provided. The torsional compensating
device comprises a first gear in driving engagement with the output
of the engine, a first Cardan joint assembly in driving engagement
with the first gear, an intermediate shaft in driving engagement
with the first joint assembly, a second joint assembly in driving
engagement with the intermediate shaft, a clutching device in
driving engagement with the second joint assembly, a torsional
element oriented substantially parallel to the output of the engine
in driving engagement with the clutching device, and a second gear
in driving engagement with the torsional element and the output of
the engine. An angular deviation of the first Cardan joint assembly
causes a cyclical acceleration of the torsional element, applying a
torque to the output of the internal combustion engine through the
second gear and the second engagement portion.
Inventors: |
Versteyhe; Mark R.J.;
(Oostkamp, BE) ; Goossens; Stijn; (Erpe-mere,
BE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dana Limited |
Maumee |
OH |
US |
|
|
Family ID: |
50686116 |
Appl. No.: |
15/150921 |
Filed: |
May 10, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14204835 |
Mar 11, 2014 |
9360080 |
|
|
15150921 |
|
|
|
|
61778745 |
Mar 13, 2013 |
|
|
|
Current U.S.
Class: |
74/572.2 |
Current CPC
Class: |
F16F 15/1204 20130101;
Y10T 74/2121 20150115 |
International
Class: |
F16F 15/12 20060101
F16F015/12 |
Claims
1-17. (canceled)
18. A parallel, torque additive torsional compensating device for
drivingly engaging an output shaft of an internal combustion
engine, the torsional compensating device comprising: a first gear
in driving engagement with a first engagement portion of the output
of the internal combustion engine; a first Cardan joint assembly in
driving engagement with the first gear; an intermediate shaft in
driving engagement with the first joint assembly; a second joint
assembly in driving engagement with the intermediate shaft; a
clutching device in driving engagement with the second joint
assembly; a torsional element in driving engagement with the
clutching device, the torsional element oriented substantially
parallel to the output of the internal combustion engine; and a
second gear in driving engagement with the torsional element and a
second engagement portion of the output of the internal combustion
engine, wherein an angular deviation of the first Cardan joint
assembly causes a cyclical acceleration of the torsional element,
the cyclical acceleration of the torsional element applying a
torque to the output of the internal combustion engine through the
second gear and the second engagement portion.
19. The torsional compensating device of claim 18, wherein the
second joint assembly is a second Cardan joint assembly.
20. The torsional compensating device of claim 18, further
comprising a third joint assembly, the third joint in driving
engagement with the first Cardan joint assembly through the first
intermediate shaft and the second joint assembly.
21. The torsional compensating device of claim 20, further
comprising a second intermediate shaft in driving engagement with
the second joint assembly and the third joint assembly.
22. The torsional compensating device of claim 20, further
comprising a joint actuator, the joint actuator positioning the
third joint assembly to adjust an angular deviation between the
first joint assembly and the third joint assembly.
23. The torsional compensating device of claim 21, wherein the
first intermediate shaft and the second intermediate shaft are
telescoping shafts.
24. The torsional compensating device of claim 18, wherein the
torsional element is one of a torsion bar and a torsion spring.
25. The torsional compensating device of claim 18, wherein the
clutching device is a clutching device which may be variably
engaged.
Description
RELATED APPLICATIONS
[0001] This application is a divisional application of U.S.
application Ser. No. 14/204,835 filed on Mar. 11, 2014, which is
incorporated by reference in its entirety. The present application
is being filed during the pendency of U.S. application Ser. No.
14/204,835.
FIELD OF THE INVENTION
[0002] The present invention relates to internal combustion engines
and more specifically to a torsion based torque ripple compensating
device for use with an internal combustion engine.
BACKGROUND OF THE INVENTION
[0003] Due to recent improvements in combustion engine technology,
there has been a trend to downsize internal combustion engines used
in vehicles. Such improvements also result in more efficient
vehicle, while maintaining similar performance characteristics and
vehicle form factors favoured by consumers
[0004] One common improvement used with internal combustion engines
is the addition of a supercharger or a turbocharger. Typically, the
addition of the supercharger or the turbocharger is used to
increase a performance of an engine that has been decreased in
displacement or a number of engine cylinders. Such improvements
typically result in an increased torque potential of the engine,
enabling the use of longer gear ratios in a transmission of the
vehicle. The longer gear ratios in the transmission enable engine
down-speeding. Engine down-speeding is a practice of operating the
engine at lower operating speeds. Such improvements typically
result in improved fuel economy, operation near their most
efficient level for a greater amount of time compared to
conventional engines, and reduced engine emissions.
[0005] In some designs, however, engine down-speeding can result in
an undesirable increase in torque ripple at low operating speeds of
the engine. For example, a significantly increased torque ripple
can appear at an engine output when the engine is operating at low
idle speeds. The torque ripple is a well-known engine dynamic that
results from torque not being delivered constantly, but
periodically during each power stroke of the operating cycle of an
internal combustion engine. FIG. 1 is a graph illustrating a torque
output of an engine during a four stroke cycle of an engine. In the
four stroke cycle, the torque ripple happens once every two turns
of a crankshaft for each cylinder of the engine. Accordingly, a
four cylinder engine will have two torque ripples per crankshaft
turn while a three cylinder engine will have three ripples every
two crankshaft turns.
[0006] An amplitude of the torque ripple also varies with an
operating speed of the engine and a load applied to the engine. A
phase of the torque ripple varies with a rotation of the engine.
Torque ripples can cause many problems for components of the
vehicle near the engine, such as but not limited to: increased
stress on the components, increased wear on the components, and
exposure of the components to severe vibrations. These problems can
damage a powertrain of the vehicle and result in poor drivability
of the vehicle. In order to reduce the effects of these problems,
smooth an operation of the engine, and improve an overall
performance of the engine, the torque ripples may be compensated
for using an engine balancing method. Many known solutions are
available for multi-cylinder engine configurations to reduce or
eliminate the stresses and vibration caused by the torque
ripples.
[0007] Torque ripple compensator devices are known in the art;
however, the known device have many shortcomings. In many
conventional vehicles, the torque ripples are compensated for using
at least one flywheel. FIG. 2 illustrates a conventional flywheel
based damping system. In other applications, a dual-mass flywheel
system may be used. An inertia of the flywheel dampens a rotational
movement of the crankshaft, which facilitates operation of the
engine running at a substantially constant speed. Flywheels may
also be used in combination with other dampers and absorbers.
[0008] A weight of the flywheel, however, can become a factor in
such torque ripple compensating devices. A lighter flywheel
accelerates faster but also loses speed quicker, while a heavier
flywheel retain speeds better compared to the lighter flywheel, but
the heavier flywheel is more difficult to slow down. However, a
heavier flywheel provides a smoother power delivery, but makes an
associated engine less responsive, and an ability to precisely
control an operating speed of the engine is reduced.
[0009] In addition to a weight of the flywheel, another problem
with conventional inertia and damping systems is a lack of
adaptability. The conventional inertia and damping systems are
designed for the worst operational condition and must be large
enough to dampen vibrations at lower operating speeds. As a result,
the conventional inertia and damping systems are not optimized for
higher operating speeds, resulting in inadequate performance.
[0010] It would be advantageous to develop a torque ripple
compensating device able to be passively or dynamically adapted for
both an amplitude and a phase of a torque ripple while minimizing
an interference with an operation of an internal combustion
engine.
SUMMARY OF THE INVENTION
[0011] Presently provided by the invention, a torque ripple
compensating device able to be passively or dynamically adapted for
both an amplitude and a phase of a torque ripple while minimizing
an interference with an operation of an internal combustion engine,
has surprisingly been discovered.
[0012] In one embodiment, the present invention is directed to a
parallel, torque additive torsional compensating device for an
internal combustion engine. The torsional compensating device
comprises a first gear in driving engagement with the output of the
engine, a first Cardan joint assembly in driving engagement with
the first gear, an intermediate shaft in driving engagement with
the first joint assembly, a second joint assembly in driving
engagement with the intermediate shaft, a clutching device in
driving engagement with the second joint assembly, a torsional
element oriented substantially parallel to the output of the engine
in driving engagement with the clutching device, and a second gear
in driving engagement with the torsional element and the output of
the engine. An angular deviation of the first Cardan joint assembly
causes a cyclical acceleration of the torsional element, applying a
torque to the output of the internal combustion engine through the
second gear and the second engagement portion.
[0013] Various aspects of this invention will become apparent to
those skilled in the art from the following detailed description of
the preferred embodiment, when read in light of the accompanying
drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0014] The above, as well as other advantages of the present
invention will become readily apparent to those skilled in the art
from the following detailed description when considered in the
light of the accompanying drawings in which:
[0015] FIG. 1 is a graph illustrating a torque output of an engine
during a four stroke cycle of an engine;
[0016] FIG. 2 is a sectional view of a flywheel based damping
system known in the prior art;
[0017] FIG. 3A is a schematic illustration of a torsional
compensating device according to a first embodiment of the present
invention;
[0018] FIG. 3B is a schematic illustration of a variation of the
torsional compensating device shown in FIG. 3A;
[0019] FIG. 3C is a schematic illustration of a variation of the
torsional compensating device shown in FIG. 3A;
[0020] FIG. 4A is a schematic illustration of a torsional
compensating device according to a second embodiment of the present
invention;
[0021] FIG. 4B is a schematic illustration of a variation of the
torsional compensating device shown in FIG. 4A;
[0022] FIG. 4C is a schematic illustration of a variation of the
torsional compensating device shown in FIG. 4A;
[0023] FIG. 5 is a schematic illustration of a torsional
compensating device according to a third embodiment of the present
invention;
[0024] FIG. 6A is a schematic illustration of the torsional
compensating device shown in FIG. 3 in a non-rotated position;
and
[0025] FIG. 6B is a schematic illustration of the torsional
compensating device shown in FIG. 3 in a rotated position.
DETAILED DESCRIPTION OF THE INVENTION
[0026] It is to be understood that the invention may assume various
alternative orientations and step sequences, except where expressly
specified to the contrary. It is also to be understood that the
specific devices and processes illustrated in the attached
drawings, and described in the following specification are simply
exemplary embodiments of the inventive concepts defined herein.
Hence, specific dimensions, directions or other physical
characteristics relating to the embodiments disclosed are not to be
considered as limiting, unless expressly stated otherwise.
[0027] FIG. 3A illustrates a torsional compensating device 100. The
torsional compensating device 100 comprises a first gear 102, a
first joint assembly 104, an intermediate shaft 106, a second joint
assembly 108, a torsional element 110, and a second gear 112. The
torque ripple compensating device 100 is in driving engagement with
a main shaft 114 of an internal combustion engine 116. The main
shaft 114 is also in driving engagement with a transmission 118.
The torsional compensating device 100 is rotatably disposed in a
housing 120 between the internal combustion engine 116 and the
transmission 118; however, it is understood that the torsional
compensating device 100 may be disposed in a portion of the
internal combustion engine 116 or the transmission 118. The
internal combustion engine 116, the torque compensating device 100,
and the transmission 118 form a portion of a vehicle (not shown);
however, it is understood that the torque compensating device 100
may be used with an internal combustion engine in other
applications. The first gear 102 and the second gear 112 of the
torsional compensating device 100 are each in driving engagement
with the main shaft 114 of the internal combustion engine 116.
[0028] The internal combustion engine 116 applies power to the main
shaft 114 through a crankshaft (not shown). The internal combustion
engine 116, for example, is a four cycle internal combustion
engine; however, it is understood that the internal combustion
engine 116 may be another type of internal combustion engine that
generates a torque ripple. It is understood that the internal
combustion engine 116 may be a hybrid power source including both
an internal combustion engine and an electric motor.
[0029] The main shaft 114 is in driving engagement with the
internal combustion engine 116 and a transmission 118. The main
shaft 114 may form a portion of one of the internal combustion
engine 116 and the transmission 118, or the main shaft 114 may be
formed separate therefrom. The main shaft 114 is in driving
engagement with the internal combustion engine 116 and the
transmission 118 through splined connections formed on each end
thereof; alternately, it is understood that the main shaft 114 may
be in driving engagement with the internal combustion engine 116
and the transmission 118 in any other conventional manner. The main
shaft 114 includes a first geared portion 122 and a second geared
portion 124.
[0030] The first geared portion 122 is in driving engagement with
the main shaft 114 through a splined connection; alternately, it is
understood that the first geared portion 122 may be in driving
engagement with the main shaft 114 in any other conventional
manner. The first geared portion 122 is a spur gear in driving
engagement with the first gear 102 of the torsional compensating
device 100; however, it is understood that the first geared portion
122 may be in driving engagement with the first gear 102 of the
torsional compensating device 100 through another type of
gearing.
[0031] The second geared portion 124 is in driving engagement with
the main shaft 114 through a splined connection; alternately, it is
understood that the second geared portion 124 may be in driving
engagement with the main shaft 114 in any other conventional
manner. The second geared portion 124 is a spur gear in driving
engagement with the second gear 112 of the torsional compensating
device 100; however, it is understood that the second geared
portion 124 may be in driving engagement with the second gear 112
of the torsional compensating device 100 through another type of
gearing.
[0032] The transmission 118 facilitates driving engagement between
the main shaft 114 of the internal combustion engine 116 and a
ground engaging device (not shown) in a plurality of drive ratios.
The transmission 118 may be an automatic transmission, a manual
transmission, a continuously variable transmission, or another type
of transmission. As known in the art, the transmission 118 may
include a clutching device (not shown).
[0033] The first gear 102 is rotatably disposed within the housing
120. The first gear 102 is rotatably supported by bearings (not
shown). The first gear 102 is a spur gear in driving engagement
with the first gear portion 122 of the main shaft 114; however, it
is understood that the first gear 102 may be in driving engagement
with the first gear portion 122 of the main shaft 114 through
another type of gearing. The first gear 102 in driving engagement
with the first gear portion 122 forms a first drive ratio. The
first gear 102 is also in driving engagement with the first joint
assembly 104. The first gear 102 is in driving engagement with the
first joint assembly 104 through a splined connection; however, it
is understood that the first gear 102 may be unitarily formed with
the first joint assembly 104 or that the first gear 102 may be in
driving engagement with the first joint assembly 104 in any
conventional manner.
[0034] The first joint assembly 104 facilitates driving engagement
between the first gear 102 and first intermediate shaft 106. The
first joint assembly 104 may be a homokinetic or a non-homokinetic
joint assembly. When the first joint assembly 104 is a
non-homokinetic joint assembly, the first joint assembly 104 may be
a Cardan joint assembly, as described hereinabove. Further, it is
understood that when the first joint assembly 104 is a
non-homokinetic joint assembly, the first joint assembly 104 may be
any type of non-homokinetic joint. When the first joint assembly
104 is a homokinetic joint assembly, the first joint assembly 104
may be a constant velocity joint assembly, which is conventional
and well known in the art. Further, it is understood that when the
first joint assembly 104 is a homokinetic joint assembly, the first
joint assembly 104 may be any type of homokinetic joint. For
simplicity, the components of the first joint assembly 104 are
represented schematically in FIG. 3A.
[0035] FIG. 3B is a schematic illustration of a variation of the
torsional compensating device shown in FIG. 3A, wherein the first
joint assembly 104 is a Cardan joint assembly. When the first joint
assembly 104 is a Cardan joint assembly, the first joint assembly
104 comprises a first driving yoke 104a, a first cross-shaft 104b,
and a first driven yoke 104c. The Cardan joint assembly is
conventional and well known in the art. The first joint assembly
104 facilitates driving engagement between the first gear 102 and
the intermediate shaft 106. In the first joint assembly 104, a
relation between the first driving yoke 104a and the first driven
yoke 104c may be described using the following equation:
tan(.beta..sub.1)=cos(.theta.)tan(.beta.)
In the above equation, .theta. is the angle between the first
driving yoke 104a and the first driven yoke 104c, .beta. is the
angle of rotation of the first driving yoke 104a and .beta..sub.1
is the angle of rotation of the first driven yoke 104c.
Furthermore, as the angles of rotation are different for the first
driving yoke 104a and the first driven yoke 104c, the rotation
speeds and accelerations will also be slightly different. The
relation between the two rotational speeds is the following:
.omega. 1 = .omega. cos ( .theta. ) 1 - sin 2 ( .beta. ) sin 2 (
.theta. ) ##EQU00001##
In the above equation, .omega. is the rotational speed of the first
driving yoke 104a and .omega..sub.1 is the rotational speed of the
first driven yoke 104c. A speed difference and an acceleration of
the first driven yoke 104c may be described using a second order
phenomenon (sinusoidal with a period of 180.degree.).
[0036] The first driving yoke 104a is a rigid member in driving
engagement with the first gear 102 and the first cross-shaft 104b.
The first driving yoke 104a is a substantially U-shaped member, but
it is understood that the first driving yoke 104a may have other
shapes. The first driving yoke 104a defines a pivot point which the
first cross-shaft 104b is rotatably coupled to.
[0037] The first cross-shaft 104b is a rigid member in driving
engagement with the first driving yoke 104a and the first driven
yoke 104c. The first cross-shaft 104b is a cross shaped member
comprising a pair of primary trunnions and a pair of secondary
trunnions, oriented transversely to one another. The first driving
yoke 104a is rotatably coupled to the primary trunnions of the
first cross-shaft 104b and the first driven yoke 104c is rotatably
coupled to the secondary trunnions of the first cross-shaft 104b.
Bearings (not shown) may be disposed between each of the trunnions
and the first driving yoke 104a and the first driven yoke 104c.
[0038] The first driven yoke 104c is a rigid member in driving
engagement with the first cross shaft 104b and the intermediate
shaft 106. The first driven yoke 104c is a substantially U-shaped
member, but it is understood that the first driven yoke 104c may
have other shapes. The first driven yoke 104c defines a pivot point
which the first cross-shaft 104b is rotatably coupled to.
[0039] The intermediate shaft 106 is rotatably disposed within the
housing 120. The intermediate shaft 106 may be rotatably supported
by bearings (not shown). The intermediate shaft 106 is a rigid
member in driving engagement with the first joint assembly 104 and
the second joint assembly 108. The intermediate shaft 106 is in
driving engagement with the first joint assembly 104 through a
splined connection; however, it is understood that the intermediate
shaft 106 may be unitarily formed with the first joint assembly 104
or that the intermediate shaft 106 may be in driving engagement
with the first joint assembly 104 in any conventional manner. The
intermediate shaft 106 is in driving engagement with the second
joint assembly 108 through a splined connection; however, it is
understood that the intermediate shaft 106 may be unitarily formed
with the second joint assembly 108 or that the intermediate shaft
106 may be in driving engagement with the second joint assembly 108
in any conventional manner. It is also understood that in
embodiments of the invention not shown, the torsional compensating
device 100 may not include the intermediate shaft 106. In such
embodiments, the first joint assembly 104 is directly drivingly
engaged with the second joint assembly 108.
[0040] The second joint assembly 108 facilitates driving engagement
between the intermediate shaft 106 and the torsional element 110.
The second joint assembly 108 may be a homokinetic or a
non-homokinetic joint assembly. When the second joint assembly 108
is a non-homokinetic joint assembly, the second joint assembly 108
may be a Cardan joint assembly, as described hereinabove. Further,
it is understood that when the second joint assembly 108 is a
non-homokinetic joint assembly, the second joint assembly 108 may
be any type of non-homokinetic joint. When the second joint
assembly 108 is a homokinetic joint assembly, the second joint
assembly 108 may be a constant velocity joint assembly, which is
conventional and well known in the art. Further, it is understood
that when the second joint assembly 108 is a homokinetic joint
assembly, the second joint assembly 108 may be any type of
homokinetic joint. For simplicity, the components of the second
joint assembly 108 are represented schematically in FIG. 3A.
[0041] FIG. 3C is a schematic illustration of a variation of the
torsional compensating device shown in FIG. 3A, wherein the first
joint assembly 104 and the second joint assembly 108 are Cardan
joint assemblies. When the second joint assembly 108 is a Cardan
joint assembly, the second joint assembly 108 comprises a second
driving yoke 108a, a second cross-shaft 108b, and a second driven
yoke 108c. When the joint assemblies 104, 108 are Cardan joint
assemblies, it is understood that the second joint assembly 108 is
not phased in relation to the first joint assembly 104 to cancel a
speed difference and a cyclical acceleration of the intermediate
shaft 106, and thus the torsional element 110, caused by the first
joint assembly 104. Further, it is understood that the second joint
assembly 108 may be phased similarly to the first joint assembly
104 or that the second joint assembly 108 may be phased partially
similar to the first joint assembly 104. An angle of the second
joint assembly 108 is substantially equal to an angle of the first
joint assembly 104.
[0042] When one of the joint assemblies 104, 108 is not a Cardan
joint assembly, it is understood that at least one of the joint
assemblies 104, 108 is not phased in relation to a remaining one of
the joint assemblies 104, 108. Phasing one of the joint assemblies
104, 108 in relation to a remaining one of the joint assemblies
104, 108 may be performed by selecting a non-homokinetic joint as
one of the joint assemblies 104, 108.
[0043] The torsional element 110 is a semi-rigid member in driving
engagement with the second joint assembly 108 and the second gear
112. The torsional element 110 is oriented substantially parallel
to the main shaft 114. The torsional element 110 comprises a
torsion bar or a torsion spring to facilitate an angular deviation
between the second joint assembly 108 and the second gear 112. In
response to the angular deviation between the second joint assembly
108 and the second gear 112, the torsional element 110 generates a
torque, which is applied to the second gear 112. The following
equation may be used to calculate a torque generated by the
torsional element 110:
T=K.DELTA.(.beta.)
in which T is the torque generated by the torsional element 110,
.DELTA.(.beta.) is an angular deviation applied to the torsional
element 110 through the first joint assembly 104 and the second
joint assembly 108, and K is a spring constant associated with the
torsional element 110.
[0044] As the angular deviation generated by the first joint
assembly 104 and the second joint assembly 108 is a second order
deviation, the torque generated by the torsional element 110 will
be a second order torque oscillation. The torque generated by the
torsional element 110 is used to damp a torque ripple produced by
the internal combustion engine 116. As a non-limiting example, a
four-cylinder internal combustion engine produces a greatest torque
ripple four times for every two rotations of the internal
combustion engine, thus such a torque ripple may be described as a
second order torque peak.
[0045] The second gear 112 is rotatably disposed within the housing
120. The second gear 112 is rotatably supported by bearings (not
shown). The second gear 112 is a spur gear in driving engagement
with the second gear portion 124 of the main shaft 114; however, it
is understood that the second gear 112 may be in driving engagement
with the second gear portion 124 of the main shaft 114 through
another type of gearing. The second gear 112 in driving engagement
with the second gear portion 124 forms a second drive ratio. It is
understood that the second drive ratio is equal to the first drive
ratio. The second gear 112 is also in driving engagement with the
first joint assembly 104. The first gear 102 is in driving
engagement with the first torsional element 110 through a splined
connection; however, it is understood that the second gear 112 may
be unitarily formed with the torsional element 110 or that the
second gear 112 may be in driving engagement with the torsional
element 110 in any conventional manner.
[0046] FIG. 4A illustrates a torsional compensating device 200. The
torque ripple compensating device 200 is a variation of the torque
ripple compensating device 100, and has similar features thereto.
The variation of the invention shown in FIG. 4A includes similar
components to the torque ripple compensating device 100 illustrated
in FIG. 3A. Similar features of the variation shown in FIG. 4A are
numbered similarly in series, with the exception of the features
described below.
[0047] The torsional compensating device 200 comprises a first gear
202, a first joint assembly 204, an intermediate shaft 206, a
second joint assembly 230, a clutching device 232, a torsional
element 234, and a second gear 212. The torque ripple compensating
device 200 is in driving engagement with a main shaft 214 of an
internal combustion engine 216. The main shaft 214 is also in
driving engagement with a transmission 218. The torsional
compensating device 200 is rotatably disposed in a housing 220
between the internal combustion engine 216 and the transmission
218; however, it is understood that the torsional compensating
device 200 may be disposed in a portion of the internal combustion
engine 216 or the transmission 218. The internal combustion engine
216, the torque compensating device 200, and the transmission 218
form a portion of a vehicle (not shown); however, it is understood
that the torque compensating device 200 may be used with an
internal combustion engine in other applications. The first gear
202 and the second gear 212 of the torsional compensating device
200 are each in driving engagement with the main shaft 214 of the
internal combustion engine 216.
[0048] The second joint assembly 230 facilitates driving engagement
between the intermediate shaft 206 and the clutching device 232.
The second joint assembly 230 may be a homokinetic or a
non-homokinetic joint assembly. When the second joint assembly 230
is a non-homokinetic joint assembly, the second joint assembly 230
may be a Cardan joint assembly, as described hereinabove. Further,
it is understood that when the second joint assembly 230 is a
non-homokinetic joint assembly, the second joint assembly 230 may
be any type of non-homokinetic joint. When the second joint
assembly 230 is a homokinetic joint assembly, the second joint
assembly 230 may be a constant velocity joint assembly, which is
conventional and well known in the art. Further, it is understood
that when the second joint assembly 230 is a homokinetic joint
assembly, the second joint assembly 230 may be any type of
homokinetic joint. For simplicity, the components of the second
joint assembly 230 are represented schematically in FIG. 3A.
[0049] FIG. 4B is a schematic illustration of a variation of the
torsional compensating device shown in FIG. 4A, wherein the first
joint assembly 204 is a Cardan joint assembly. When the first joint
assembly 204 is a Cardan joint assembly, the first joint assembly
204 comprises a first driving yoke 204a, a first cross-shaft 204b,
and a first driven yoke 204c.
[0050] FIG. 4C is a schematic illustration of a variation of the
torsional compensating device shown in FIG. 4A, wherein the first
joint assembly 204 and the second joint assembly 230 are Cardan
joint assemblies. When the second joint assembly 230 is a Cardan
joint assembly, the second joint assembly 230 comprises a second
driving yoke 230a, a second cross-shaft 230b, and a second driven
yoke 230c.
[0051] When the joint assemblies 204, 230 are Cardan joint
assemblies, it is understood that the second joint assembly 230 is
not phased in relation to the first joint assembly 204 to cancel a
speed difference and a cyclical acceleration of the intermediate
shaft 206, and thus the torsional element 234, caused by the first
joint assembly 204. Further, it is understood that the second joint
assembly 230 may be phased similarly to the first joint assembly
204 or that the second joint assembly 230 may be phased partially
similar to the first joint assembly 204. An angle of the second
joint assembly 230 is substantially equal to an angle of the first
joint assembly 204.
[0052] When one of the joint assemblies 204, 230 is not a Cardan
joint assembly, it is understood that at least one of the joint
assemblies 204, 230 is not phased in relation to a remaining one of
the joint assemblies 204, 230. Phasing one of the joint assemblies
204, 230 in relation to a remaining one of the joint assemblies
204, 230 may be performed by selecting a non-homokinetic joint as
one of the joint assemblies 204, 230.
[0053] The clutching device 232 facilitates variable driving
engagement between the second joint assembly 230 and the torsional
element 234; however, it is understood that the clutching device
232 may be positioned at another location in the torsional
compensating device 200. The clutching device 232 is a plate style
clutch; however, it is understood that the clutching device 232 may
be a cone style clutch or another type of clutching device that can
be variably engaged. The clutching device 232 is in communication
with a control system (not shown) to control an engagement level of
the clutching device 232. Typically, the clutching device 232 is in
an engaged position and the clutching device 232 is only variably
engaged to adjust a relationship between the second joint assembly
230 and the torsional element 234. When the relationship between
the second joint assembly 230 and the torsional element 234 is
adjusted, the clutching device 232 is placed in a "slipping"
condition. Typically, the relationship between the second joint
assembly 230 and the torsional element 234 is adjusted in very
small increments.
[0054] Further, it is understood that by disengaging the clutching
device 232, a torque generated by the torsional compensating device
200 can be eliminated. Disengaging the clutching device 232 may be
preferable at higher operating speeds of the internal combustion
engine 216, when a torque ripple produced by the internal
combustion engine 216 is less severe, for example.
[0055] The torsional element 234 is a semi-rigid member in driving
engagement with the second joint assembly 230 and the second gear
212. The torsional element 234 is oriented substantially parallel
to the main shaft 214. The torsional element 234 comprises a
torsion bar or a torsion spring to facilitate an angular deviation
between the clutching device 232 and the second gear 212. In
response to the angular deviation between the second joint assembly
230 and the second gear 212, the torsional element 234 generates a
torque, which is applied to the second gear 212. The equation
presented above may be used to calculate a torque generated by the
torsional element 234.
[0056] As the angular deviation generated by the first joint
assembly 204 and the second joint assembly 230 is a second order
deviation, the torque generated by the torsional element 234 will
be a second order torque oscillation. The torque generated by the
torsional element 234 is used to damp a torque ripple produced by
the internal combustion engine 216. As a non-limiting example, a
four-cylinder internal combustion engine produces a greatest torque
ripple four times for every two rotations of the internal
combustion engine, thus such a torque ripple may be described as a
second order torque peak.
[0057] FIG. 5 illustrates a torsional compensating device 300. The
torque ripple compensating device 300 is a variation of the torque
ripple compensating device 100, and has similar features thereto.
The variation of the invention shown in FIG. 5 includes similar
components to the torque ripple compensating device 100 illustrated
in FIG. 3A. Similar features of the variation shown in FIG. 5 are
numbered similarly in series, with the exception of the features
described below.
[0058] The torsional compensating device 300 comprises a first gear
302, a first joint assembly 340, a first intermediate shaft 342, a
second joint assembly 344, a second intermediate shaft 346, a third
joint assembly 348, a joint actuator 350, a torsional element 352,
and a second gear 312. The torque ripple compensating device 300 is
in driving engagement with a main shaft 314 of an internal
combustion engine 316. The main shaft 314 is also in driving
engagement with a transmission 318. The torsional compensating
device 300 is rotatably disposed in a housing 320 between the
internal combustion engine 316 and the transmission 318; however,
it is understood that the torsional compensating device 300 may be
disposed in a portion of the internal combustion engine 316 or the
transmission 318. The internal combustion engine 316, the torque
compensating device 300, and the transmission 318 form a portion of
a vehicle (not shown); however, it is understood that the torque
compensating device 300 may be used with an internal combustion
engine in other applications. The first gear 302 and the second
gear 312 of the torsional compensating device 300 are each in
driving engagement with the main shaft 314 of the internal
combustion engine 316.
[0059] The first joint assembly 340 facilitates driving engagement
between the first gear 302 and first intermediate shaft 342. The
first joint assembly 340 may be a homokinetic or a non-homokinetic
joint assembly. When the first joint assembly 340 is a
non-homokinetic joint assembly, the first joint assembly 340 may be
a Cardan joint assembly, as described hereinabove. Further, it is
understood that when the first joint assembly 340 is a
non-homokinetic joint assembly, the first joint assembly 340 may be
any type of non-homokinetic joint. When the first joint assembly
340 is a homokinetic joint assembly, the first joint assembly 340
may be a constant velocity joint assembly, which is conventional
and well known in the art. Further, it is understood that when the
first joint assembly 340 is a homokinetic joint assembly, the first
joint assembly 340 may be any type of homokinetic joint.
[0060] The first intermediate shaft 342 is rotatably disposed
within the housing 320. The first intermediate shaft 342 may be
rotatably supported by bearings (not shown). The first intermediate
shaft 342 is a rigid member in driving engagement with the first
joint assembly 340 and the second joint assembly 344. The first
intermediate shaft 342 is a telescoping shaft which facilitates
adjusting a position of the second joint assembly 344 with respect
to the first joint assembly 340. The first intermediate shaft 342
is in driving engagement with the first joint assembly 340 through
a splined connection; however, it is understood that the first
intermediate shaft 342 may be unitarily formed with the first joint
assembly 340 or that the first intermediate shaft 342 may be in
driving engagement with the first joint assembly 340 in any
conventional manner. The first intermediate shaft 342 is in driving
engagement with the second joint assembly 344 through a splined
connection; however, it is understood that the first intermediate
shaft 342 may be unitarily formed with the second joint assembly
344 or that the first intermediate shaft 342 may be in driving
engagement with the second joint assembly 344 in any conventional
manner. It is also understood that in embodiments of the invention
not shown, the torsional compensating device 300 may not include
the first intermediate shaft 342. In such embodiments, the first
joint assembly 340 is directly drivingly engaged with the second
joint assembly 344 in a telescoping manner.
[0061] The second joint assembly 344 facilitates driving engagement
between the first intermediate shaft 342 and the second
intermediate shaft 346. The second joint assembly 344 may be a
homokinetic or a non-homokinetic joint assembly. When the second
joint assembly 344 is a non-homokinetic joint assembly, the second
joint assembly 344 may be a Cardan joint assembly, as described
hereinabove. Further, it is understood that when the second joint
assembly 344 is a non-homokinetic joint assembly, the second joint
assembly 344 may be any type of non-homokinetic joint. When the
second joint assembly 344 is a homokinetic joint assembly, the
second joint assembly 344 may be a constant velocity joint
assembly, which is conventional and well known in the art. Further,
it is understood that when the second joint assembly 344 is a
homokinetic joint assembly, the second joint assembly 344 may be
any type of homokinetic joint.
[0062] The second intermediate shaft 346 is rotatably disposed
within the housing 320. The second intermediate shaft 346 may be
rotatably supported by bearings (not shown). The second
intermediate shaft 346 is a rigid member in driving engagement with
the second joint assembly 344 and the third joint assembly 348. The
second intermediate shaft 346 is a telescoping shaft which
facilitates adjusting a position of the second joint assembly 344
with respect to the third joint assembly 348. The second
intermediate shaft 346 is in driving engagement with the second
joint assembly 344 through a splined connection; however, it is
understood that the second intermediate shaft 346 may be unitarily
formed with the second joint assembly 344 or that the second
intermediate shaft 346 may be in driving engagement with the second
joint assembly 344 in any conventional manner. The second
intermediate shaft 346 is in driving engagement with the third
joint assembly 348 through a splined connection; however, it is
understood that the second intermediate shaft 346 may be unitarily
formed with the third joint assembly 348 or that the second
intermediate shaft 346 may be in driving engagement with the third
joint assembly 348 in any conventional manner. It is also
understood that in embodiments of the invention not shown, the
torsional compensating device 300 may not include the second
intermediate shaft 346. In such embodiments, the second joint
assembly 344 is directly drivingly engaged with the third joint
assembly 348 in a telescoping manner.
[0063] The third joint assembly 348 facilitates driving engagement
between the second intermediate shaft 346 and the torsional element
352. The third joint assembly 348 may be a homokinetic or a
non-homokinetic joint assembly. When the third joint assembly 348
is a non-homokinetic joint assembly, the third joint assembly 348
may be a Cardan joint assembly, as described hereinabove. Further,
it is understood that when the third joint assembly 348 is a
non-homokinetic joint assembly, the third joint assembly 348 may be
any type of non-homokinetic joint. When the third joint assembly
348 is a homokinetic joint assembly, the third joint assembly 348
may be a constant velocity joint assembly, which is conventional
and well known in the art. Further, it is understood that when the
third joint assembly 348 is a homokinetic joint assembly, the third
joint assembly 348 may be any type of homokinetic joint.
[0064] It is understood that at least one of the second joint
assembly 344 and the third joint assembly 348 is not phased in
relation to the first joint assembly 340. Phasing one of the second
joint assembly 344 and the third joint assembly 348 in relation to
the first joint assembly 340 may be performed by selecting a
non-homokinetic joint as at least one of the first joint assembly
340, the second joint assembly 344, and the third joint assembly
348; however, it is understood that the two or all of the joint
assemblies 340, 344, 348 may be non-homokinetic joints, as long as
the joint assemblies 340, 344, 348 are arranged to not cancel a
speed difference and an acceleration of a portion of the third
joint assembly 348 in driving engagement with the torsional element
352 compared to a portion of the first joint assembly 340 in
driving engagement with the first gear 202.
[0065] The torsional element 352 is a semi-rigid member in driving
engagement with the third joint assembly 348 and the second gear
312. The torsional element 352 is oriented substantially parallel
to the main shaft 314. The torsional element 352 comprises a
torsion bar or a torsion spring to facilitate an angular deviation
between the third joint assembly 348 and the second gear 312. In
response to the angular deviation between the third joint assembly
348 and the second gear 312, the torsional element 352 generates a
torque, which is applied to the second gear 312. The equation
presented above may be used to calculate a torque generated by the
torsional element 352.
[0066] The joint actuator 350 is an actuator in driving engagement
with the second joint assembly 344 and the housing 320. The joint
actuator 350 may be a hydraulic actuator, a pneumatic actuator, a
screw driven actuator, or any other type of known actuator. In
response to a control signal from a controller (not shown), the
joint actuator 350 applies a force to the second joint assembly 344
to move the second joint assembly 344 with respect to the first
joint assembly 340 and the third joint assembly 348, changing an
angle of each of the joint assemblies 340, 344, 348 and a length of
the intermediate shafts 342, 346. In response to the second joint
assembly 344 being moved with respect to the first joint assembly
340 and the third joint assembly 348, a speed difference and an
acceleration of a portion of the third joint assembly 348 is
adjusted compared to a portion of the first joint assembly 340 in
driving engagement with the first gear 202, thus changing an
amplitude of a torque applied to the second gear 312 generated by
the torsional element 352.
[0067] It is also understood that as an alternative to the
embodiments of the invention described herein, a variation of the
torsional compensating device 300 including four joint assemblies,
in which a joint actuator moves a shaft portion of the torsional
compensating device in a manner parallel to a main shaft, is within
the scope of the present invention.
[0068] In use, the torsional compensating device 100, 200, 300
generates a torque using the torsional element 110, 234, 352 and at
least one of the joint assemblies 104, 108, 204, 230, 340, 344, 348
to damp a torque ripple produced by the internal combustion engine
116, 216, 316. The torsional compensating device 100, 200, 300 is a
parallel, torque additive device for the internal combustion engine
116, 216, 316.
[0069] To ensure that a torque generated by the torsional
compensating device 100, 200, 300 is correcting the torque ripple
produced by the internal combustion engine 116, 216, 316 and not
increasing the torque ripple produced by the internal combustion
engine 116, 216, 316, a phase at which the torsional compensating
device 100, 200, 300 operates at must be set to a correct value. A
phase at which the torsional compensating device 100, 200, 300
operates at may be adjusted dynamically or may be set by a design
and orientation of the torsional compensating device 100, 200, 300
in applications in which dynamic phase adjustment is not necessary.
When a design and orientation of the torsional compensating device
100, 200, 300 determines a phase, a position of the torsional
compensating device 100, 200, 300 with respect to a crankshaft
angle of the internal combustion engine 116, 216, 316 determined
the phase. The position of the torsional compensating device 116,
216, 316 is determined by a position of a plane formed by the joint
assemblies 104, 108, 204, 230, 340, 344, 348 compared to a plane of
the crankshaft of the internal combustion engine 116, 216, 316. As
a non-limiting example, if the plane formed by the joint assemblies
104, 108, 204, 230, 340, 344, 348 is the same as a plane of a
plurality of pistons of the internal combustion engine 116, 216,
316, the torsional compensating device 100, 200, 300 will have a
phase substantially equal to 0 degrees, while placing the plane
formed by the joint assemblies 104, 108, 204, 230, 340, 344, 348
inclined compared to the plane of a plurality of pistons will
create some de-phasing.
[0070] A phase at which the torsional compensating device 100, 200,
300 operates at may be adjusted dynamically. A first way in which a
phase of the torsional compensating device 200 may be adjusted
dynamically during the operation of the torsional compensating
device 200 is through the operation of the clutching device 232. As
described hereinabove, by disengaging the clutching device 232, the
clutching device 232 is placed in a "slipping" condition. When the
clutching device 232 is placed in a "slipping" condition, the
relationship between the second joint assembly 230 and the
torsional element 234 is adjusted, resulting in an adjustment to a
phase of the torsional compensating device 200.
[0071] A second way in which a phase of the torsional compensating
device 100, 200, 300 may be adjusted dynamically during the
operation of the torsional compensating device 100, 200, 300 is
through rotation of the torsional compensating device 100, 200, 300
about the main shaft 114, 214, 314. FIGS. 6A and 6B illustrates the
torsional compensating device 100 in both a non-rotated position
and a rotated position. It is understood that the torsional
compensating device 200, 300 may be rotated similarly. A phase
actuator 400 facilitates rotating the torsional compensating device
100 about the main shaft 114. In rotating the torsional
compensating device 100 about the main shaft 114, the plane formed
by the joint assemblies 104, 108 is adjusted from the plane of a
plurality of pistons of the internal combustion engine 116. By
rotating the torsional compensating device 100, a de-phasing occurs
between a torque generated by the torsional compensating device 100
and the torque ripple produced by the internal combustion engine
116. It is understood that rotating the torsional compensating
device 100, 200, 300 may be performed prior to operation of the
internal combustion engine 116, 216, 316, performed dynamically
during operation of the internal combustion engine 116, 216, 316,
or incorporated into a fixed design of the torsional compensating
device 100, 200, 300.
[0072] It is also understood that as an alternative to the
embodiments of the invention described herein, it is within the
scope of the present invention for alternative drive ratios to be
incorporated into the torsional compensating device 100, 200, 300.
As described hereinabove, a gear ratio of 1:1 between the first
geared portion 122, 222, 322 and the first gear 102, 202, 302 and
the second geared portion 124, 224, 324 and the second gear 112,
212, 312 is useful to damp second order torque ripples produced by
the internal combustion engine 116, 216, 316, as joint assemblies
104, 108, 204, 230, 340, 344, 348 introduce a second order speed
oscillation. Such a gear ratio is useful for a four cylinder
engine, in which a biggest torque ripple occurs at the second
order. As a non-limiting example, a gear ratio of 1:1.5 between the
first geared portion 122, 222, 322 and the first gear 102, 202, 302
and the second geared portion 124, 224, 324 and the second gear
112, 212, 312 is also useful. In such a variation, the first gear
102, 202, 302 would be driven one and a half times as fast as the
main shaft 114, 214, 314, and torque corrections generated by the
torsional compensating device 100, 200, 300 would occur at the
third order. Torque corrections occurring at the third order could
be used to damp a torque ripple of the internal combustion engine
116, 216, 316 having three cylinders, and thus a torque ripple that
occurs three times every two turns.
[0073] As described hereinabove, it is within the scope of the
present invention for the torsional compensating device 100, 200,
300 to include a single non-homokinetic joint as one of the joint
assemblies 104, 108, 204, 230, 340, 344, 348. A remaining joint
assembly 104, 108, 204, 230 or joint assemblies 340, 344, 348 would
be a homokinetic joint as described hereinabove. Such a torsional
compensating device 100, 200, 300 would be useful in applications
in which torque ripples produced by the internal combustion engine
116, 216, 316 are relatively small. An amplitude of torque peaks
created by such a torsional compensating device 100, 200, 300 would
be smaller than a torsional compensating device 100, 200, 300
including two non-homokinetic joints.
[0074] Based on the foregoing, it can be appreciated that the
torsional compensating device 100, 200, 300 described and depicted
herein has several advantages over the known art. Some of the
advantages of the torsional compensating device 100, 200, 300
include, but are not limited to, the torsional compensating device
100, 200, 300 that can be actively regulated in phase and amplitude
and the torsional compensating device 100, 200, 300 is formed from
common and cost effective components. Additionally, the torsional
compensating device 100, 200, 300 is a configurable design, which
affords significant flexibility through a selection of the
torsional element 110, 234, 352 and an angle of the joint
assemblies 104, 108, 204, 230, 340, 344, 348. Further, the
torsional compensating device 100, 200, 300 is a parallel additive
torque device which does not dissipate an excessive amount of
energy through frictional losses or through damping.
[0075] In accordance with the provisions of the patent statutes,
the present invention has been described in what is considered to
represent its preferred embodiments. However, it should be noted
that the invention can be practiced otherwise than as specifically
illustrated and described without departing from its spirit or
scope.
* * * * *