U.S. patent application number 14/425842 was filed with the patent office on 2015-08-13 for ball type cvt/ivt including planetary gear sets.
The applicant listed for this patent is Dana Limited. Invention is credited to Kenneth E. Cooper, Timothy J. Morscheck, Andrew W. Phillips.
Application Number | 20150226299 14/425842 |
Document ID | / |
Family ID | 50237554 |
Filed Date | 2015-08-13 |
United States Patent
Application |
20150226299 |
Kind Code |
A1 |
Cooper; Kenneth E. ; et
al. |
August 13, 2015 |
BALL TYPE CVT/IVT INCLUDING PLANETARY GEAR SETS
Abstract
Disclosed herein are power transmissions having one or more
operational modes, for example, a continuously variable
transmission (CVT) mode, an infinitely variable transmission (WT)
mode, and an WT/CVT mode, that can be selected for by engaging
different clutches and brakes. Disclosed herein are power
transmissions comprising a power input shaft, one or more planetary
gear sets, a variator (such as a CVT), and one or more clutches and
brakes. In some embodiments, a first brake selects an WT mode, a
second brake selects a CVT mode, and a third brake selects an
WT/CVT mode.
Inventors: |
Cooper; Kenneth E.; (Toledo,
OH) ; Morscheck; Timothy J.; (Portage, MI) ;
Phillips; Andrew W.; (Rochester, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dana Limited |
Maumee |
OH |
US |
|
|
Family ID: |
50237554 |
Appl. No.: |
14/425842 |
Filed: |
September 3, 2013 |
PCT Filed: |
September 3, 2013 |
PCT NO: |
PCT/US13/57838 |
371 Date: |
March 4, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61697912 |
Sep 7, 2012 |
|
|
|
61783853 |
Mar 14, 2013 |
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Current U.S.
Class: |
475/214 ;
475/207 |
Current CPC
Class: |
F16H 15/28 20130101;
F16H 2037/0893 20130101; F16H 37/0853 20130101; F16H 2037/0873
20130101; F16H 15/503 20130101; F16H 15/52 20130101 |
International
Class: |
F16H 37/08 20060101
F16H037/08; F16H 15/52 20060101 F16H015/52 |
Claims
1-29. (canceled)
30. An apparatus for power transmission comprising: a power input
shaft; a planetary gear set mechanically coupled to the power input
shaft; a variator mechanically coupled to the gear set; and three
brakes for switching among a plurality of operational modes of the
power transmission apparatus.
31. The power transmission apparatus of claim 30, wherein a
planetary gear set is coupled to the output of the variator and to
the final reduction.
32. The power transmission apparatus of claim 30, wherein the three
brakes are configured to be selectively engaged or released to
switch among the modes of the power transmission apparatus.
33. The power transmission apparatus of claim 30, wherein the
variator is coupled to a planet of the planetary gear set.
34. The power transmission apparatus of claim 32, wherein the the
first brake engages said IVT mode, said second brake engages said
CVT mode and the third brake is for applying an overdrive ratio.
Description
CROSS-REFERENCE
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/697,912, filed Sep. 7, 2012 and U.S. Provisional
Application No. 61/783,853, filed Mar. 14, 2013, which applications
are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Automatic and manual transmissions are commonly used on
automobile vehicles. Such transmissions have become more and more
complicated since the engine speed has to be adjusted to limit the
consumption and the emissions of the vehicle. The finer control of
the engine speed in usual transmissions can typically only be
accomplished by adding gears and increasing the overall complexity
and cost. As a result, 6-speed manual transmissions have become as
frequent as 8 or 9 speed automatic transmissions.
SUMMARY OF THE INVENTION
[0003] Systems, devices, and methods are provided for transmitting
power in a smoother and more efficient manner, preferably with less
or smaller components. In some embodiments, power transmissions
disclosed herein have one or more operational modes, e.g., a
continuously variable transmission (CVT) mode, an infinitely
variable transmission (IVT) mode, and an IVT/CVT mode. In some
embodiments, the operational modes are selected for by engaging
different clutches and/or brakes.
[0004] Described herein, in certain embodiments, is an apparatus
for power transmission. In some embodiments, the power transmission
apparatus comprises a power input shaft, one or more planetary gear
sets, a variator, and one or more clutches and brakes (also called
brake clutches). In some embodiments, a first planetary gear set is
mechanically coupled to the power input shaft. In some embodiments,
the variator is mechanically coupled to the some of the planetary
gear sets. In some embodiments, the one or more clutches and brakes
are to be used for switching among a plurality of operational modes
of the power transmission apparatus.
[0005] In some embodiments, the components of the power
transmission have various configurations and comprise a variety of
different types of parts. In some embodiments, the one or more
clutches and brakes are configured to be selectively engaged or
released to switch between the modes of the power transmission
apparatus. In some embodiments, the gear set comprises a
ravigneaux-like gear set, a dual sun planetary gear set, or a three
sun planetary gear set. In some embodiments, the variator is
coupled to a sun, a ring or a planet carrier of the planetary gear
set. In some embodiments, the variator comprises a continuously
variable transmission (CVT), such as a traction type, also known as
ball-type CVT. In some embodiments, the power transmission further
comprises a first and second ball ramp disposed on either side of
the variator for providing a clamping force for torque transfer. In
some embodiments, the power input shaft is coupled to a damper and
the output of an internal combustion engine.
[0006] In some embodiments, the one or more clutches and brakes
comprises a first clutch or brake for selecting an infinitely
variable transmission (IVT) mode of the power transmission
apparatus. In some embodiments, the first clutch or brake is
configured to couple to an output of a planet gear of the gear set.
In some embodiments, the one or more clutches or brakes comprises a
second clutch or brake for selecting a continuously variable
transmission (CVT) mode of the power transmission apparatus. In
some embodiments, the second clutch or brake is configured to
couple to an output of a sun gear of the gear set. In some
embodiments, the one or more clutches or brake comprises a third
clutch or brake for selecting an infinitely and continuously
variable transmission (IVT/CVT) mode of the power transmission
apparatus. In some embodiments, the third clutch or brake is
configured to couple to a ring gear or a sun of the gear set. In
some embodiments, the one or more clutches comprises an overdrive
clutch or brake for affecting a speed increase. In some
embodiments, the one or more clutches comprise a direct drive
clutch.
[0007] In some embodiments, the power transmission apparatus
further comprises a power output mechanically coupled to the
variator. In some embodiments, the power output comprises a power
output ring for transmitting power from the variator to a
differential box. In some embodiments, the power output comprises a
power output shaft, In some embodiments, the power transmission
further comprises an output gear set mechanically coupled to the
power output shaft for transmitting power from the variator to a
differential box.
INCORPORATION BY REFERENCE
[0008] All publications, patents, and patent applications mentioned
in this specification are herein incorporated by reference to the
same extent as if each individual publication, patent, or patent
application was specifically and individually indicated to be
incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The novel features of the invention are set forth with
particularity in the appended claims. A better understanding of the
features and advantages of the present invention will be obtained
by reference to the following detailed description that sets forth
illustrative embodiments, in which the principles of the invention
are utilized, and the accompanying drawings of which:
[0010] FIG. 1 is a cutaway view of a currently known and used
continuously variable transmission (CVT);
[0011] FIG. 2 is a magnified cutaway view of a ball and ring of the
CVP of FIG. 1;
[0012] FIG. 3 is a block diagram of a transmission based on CVP of
FIG. 1 as used in a motor vehicle transmission;
[0013] FIG. 4 is a block diagram of a multi-mode transmission
according to an embodiment of the present disclosure;
[0014] FIG. 5 is a block diagram of a multi-mode transmission
according to another embodiment of the present disclosure;
[0015] FIG. 6 is a block diagram of a multi-mode transmission
according to yet another embodiment of the present disclosure;
and
[0016] FIG. 7 is a block diagram of a multi-mode transmission
according to a further embodiment of the present disclosure
[0017] FIG. 8 is a block diagram of a multi-mode transmission
according to a further embodiment of the present disclosure
DETAILED DESCRIPTION OF THE INVENTION
[0018] Automatic and manual transmissions commonly used on
automobile vehicles are Continuously Variable Transmissions or
CVTs. Such CVTs include many types, such as belts with variable
pulleys, toroidal, and conical. The principle of a CVT is that it
enables the engine to run at its most efficient rotation speed by
changing steplessly the transmission ratio in function of the speed
of the vehicle. If needed, for example, when accelerating, the CVT
can also shift to a ratio providing more power. A CVT can change
the ratio from the minimum to the maximum ratio without any
interruption of the power transmission, at the opposite of usual
transmissions which require an interruption of the power
transmission by disengaging to shift of ratio. A specific use of
CVTs is the Infinite Variable Transmission or IVT. Where the CVT is
limited at positive speed ratios, the IVT configuration can perform
a neutral gear and even reverse steplessly. A CVT can be used as an
IVT in some driveline configurations.
[0019] Described herein are driveline configurations based on a
ball type CVT, also known as CVP (Constant Variable Planetary), for
which patents were applied for by Fallbrook Technologies, Inc.
under the references US20040616399P and AU2011224083A1. This CVT is
composed of a certain number of balls, depending on the
application, two discs with a conical surface contact with the
balls, as input and output, and an idler as shown in FIG. 1. This
CVT is composed of a certain number of balls, depending on the
application, two discs with a conical surface contact with the
balls, as input 995 and output 996, and an idler 999 as shown in
FIG. 1. The balls 997 are mounted on axles 998, themselves held in
a cage or carrier allowing changing the ratio by tilting the ball's
axles. Other types of ball CVTs also exist, including the Milner
Continuous Variable Transmission (MCVT) (MCVT).
[0020] The working principle is shown on FIG. 2. The CVP itself
works with a traction fluid. The lubricant between the ball and the
conical rings acts as a solid at high pressure, transferring the
power from the input ring, through the balls, to the output ring.
By tilting the ball's axis, the ratio can be changed between input
and output. When the axis is horizontal the ratio is one, when the
axis is tilted the distance between the axis and the contact point
change, modifying the overall ratio. All the ball's axes are tilted
at the same time with a mechanism included in the cage.
[0021] In an automobile, the CVT is used to replace a traditional
transmission and is located between the engine 100 and the
differential 102 as shown on FIG. 3. In some instances, a torsional
damper 101 is introduced between the engine 100 and the CVT 103 to
avoid transferring torque peaks and vibrations that could seriously
damage the CVT. In some configurations, this damper is coupled with
a clutch for the starting function.
[0022] In some instances, the continuously variable transmission
(CVT) is less than ideal. Power ratios may not be the most
effective and efficient, power transmission may be frequently
interrupted, and the transmissions may involve the use of bulky and
heavy parts. Therefore, improved continuously variable
transmissions (CVT) overcoming at least some of these problems are
desired.
[0023] Systems, devices, and methods are provided for transmitting
power in a smoother and more efficient manner. In some embodiments,
this is accomplishes with fewer or smaller components. In some
embodiments, power transmissions disclosed herein have one or more
operational modes, e.g., a continuously variable transmission (CVT)
mode, an infinitely variable transmission (IVT) mode, and an
IVT/CVT mode, that are selected for by engaging different clutches
or brakes. In some embodiments, the apparatus allows for mode
shifting between the continuously variable (CVT) mode and
infinitely variable (IVT) mode with a minimum number of clutches
and brakes.
[0024] Concept 1c/
[0025] In an automobile 20, the CVT 203 is used to replace a
traditional transmission and is located between the engine 200 and
the differential 202. In some instances, a torsional damper 201 is
introduced between the engine 200 and planetary gears 211 and 212
as shown on FIG. 4. Configuration 1c/ (FIG. 4) uses a dual sun
planetary 211 and 212 before going to the variator 213. In the dual
sun planetary, the planets of first plane of gears planetary 211 of
second plane of gears planetary 212 are made of a single piece. In
some embodiments, the variator output is linked to an additional
planetary 217. In some embodiments, this planetary is locked to
turn with a 1:1 ratio by applying the clutch 216 to lock its sun
and planet carrier together. In some embodiments, a speed increase
is achieved by having more spread by applying the overdrive clutch
216 to lock the sun of the planetary to the ground. In some
embodiments, the ring of this planetary is then linked to the final
drive 222 and differential 202. In some embodiments, the second
ring of the variator is linked to the planet carrier of the third
planetary. In some embodiments, the configuration comprises two
brakes, one for IVT mode 214 and one for CVT mode 215. In some
embodiments, the central part of that configuration comprises the
variator described above. In some embodiments, a ball ramp on each
side of the variator provides the clamping force necessary to
transfer the torque.
[0026] In some embodiments, the carrier 218 of the dual sun
planetary is linked to the variator input ring 219. In some
embodiments, the carrier 218 of the dual sun planetary is connected
to the housing in IVT mode by applying the IVT clutch 214. In some
embodiments, the sun of the second planetary 220 is linked to the
carrier of the variator 221. In some embodiments, the sun of the
second planetary 220 is connected to the housing in CVT mode by
applying the CVT clutch 215. In some embodiments, the overall ratio
is typically the product of the dual sun planetary ratio, the
variator ratio, the output planetary 217 ratio and the final drive
ratio 222. In some embodiments, standstill, very low vehicle speeds
and reverse is achieved by the IVT mode of the variator.
[0027] In some embodiments, the transition between the two modes
(CVT and IVT) is simply done by releasing one brake and closing the
other. Furthermore, the clutch 216 of the output planetary might be
used to select a ratio 1:1 in the output planetary 217 or an
overdrive ratio. The transition between these two additional ratios
is simply done by changing the parts engaged by the clutch 216. In
some embodiments, this device is able to change continuously its
ratio to provide the best ratio achievable for the engine in
function of the objectives of consumption or power. In certain
instances, in a manual or automatic transmission, only some
predetermined and discrete ratios are available and an interruption
of the power transmission is needed to shift the ratio. In certain
instances, the only interruption of power in this device is to
change modes. Other advantages include, but are not limited to: a
small final drive (in one step, not needing a countershaft) and
cost effectiveness of the system. In some embodiments, spread is
higher than traditional gearboxes by adding the third planetary,
which improves global efficiency of the vehicle. In some
embodiments, the apparatus allows for mode shifting between the
continuously variable (CVT) mode and infinitely variable (IVT) mode
with a minimum number of brakes.
[0028] Concept 1d/
[0029] In an automobile 30, the CVT 303 is used to replace a
traditional transmission and is located between the engine 300 and
the differential 302. In some instances, a torsional damper 301 is
introduced between the engine 300 and planetary gears 311, 312 and
313 as shown on FIG. 5. Configuration 1d/ (FIG. 5) uses a three sun
planetary ((311), (312,) and (313)) before going to the variator
(314). In the three sun planetary, the planets of first plane of
gears (planetary (311)) of second plane of gears (planetary (312))
and third plane of gears (planetary (313)) are made of a single
piece. In some embodiments, the variator output ring (320) is then
linked to the final drive (322) and differential. In some
embodiments, the configuration comprises three brake clutches, one
for IVT mode (315); one for CVT mode (316) and one for an IVT/CVT
mode (317) where the variator input ring (319) and the variator
carrier (321) are both driven. In some embodiments, the central
part of this configuration is the variator described above. In some
embodiments, a ball ramp on each side of the variator provides the
clamping force necessary to transfer the torque.
[0030] In some embodiments, the carrier (318) of the three sun
planetary is linked to the variator input ring (319). In some
embodiments, the carrier (318) is connected to the housing in IVT
mode by applying a brake (315). In some embodiments, the sun of the
third planetary (313) is linked to the carrier of the variator
(321). In some embodiments, the sun of the third planetary (313) is
connected to the housing in CVT mode by applying brake (316). In
some embodiments, in IVT/CVT mode, the sun of the second planetary
is connected to the housing by applying brake (317), thus letting
the variator input ring (319) and variator carrier (321) be both
driven. In some embodiments, this IVT/CVT mode lies in-between the
IVT mode and the CVT mode concerning speeds. In some embodiments,
the overall ratio is the product of the three sun planetary ratio,
the variator ratio and the final drive ratio. In some embodiments,
standstill, very low vehicle speeds and reverse are typically
achieved by the IVT mode of the variator.
[0031] In some embodiments, the transition between the three modes
is simply done by engaging one brake and releasing the others. In
some embodiments, this device is able to change continuously its
ratio to provide the best ratio achievable for the engine in
function of the objectives of consumption or power. In a manual or
automatic transmission. In certain instances, in a manual or
automatic transmission, only some predetermined and discrete ratios
are available and an interruption of the power transmission is
needed to shift the ratio. In some embodiments, the only
interruption of power in this device is to change modes. In some
embodiments, another advantage is that spread is higher than
traditional gearboxes by having those three modes, which can
improve global efficiency of the vehicle. In some embodiments, the
apparatus allows for mode shifting between the continuously
variable (CVT) mode, infinitely variable (IVT) mode and the
combined IVT/CVT mode with a minimum number of brakes.
[0032] Concept 1 e/
[0033] In an automobile 40, the CVT 403 is used to replace a
traditional transmission and is located between the engine 400 and
the differential 402. In some instances, a torsional damper 401 is
introduced between the engine 400 and ravigneaux-like planetary 411
as shown on FIG. 6. Configuration 1e/ (FIG. 6) uses a
ravigneaux-like planetary (411) before going to the variator (412).
In the Ravigneaux-like planetary, the planets of first plane of
gears and of second plane of gears are made of a single piece. In
some embodiments, the variator output ring (420) is then linked to
the final drive (422) and differential. In some embodiments, the
configuration comprises three brake clutches, one for IVT mode
(413); one for CVT mode (414), and one for an IVT/CVT mode (415)
where the variator input ring (419) and the variator carrier (421)
are both driven. In some embodiments, the central part of that
configuration is the variator described above. In some embodiments,
a ball ramp on each side of the variator provides the clamping
force necessary to transfer the torque.
[0034] In some embodiments, the carrier (418) of the
ravigneaux-like planetary is linked to the variator input ring
(419). In some embodiments, the carrier (418) is connected to the
housing in IVT mode by applying brake (413). In some embodiments,
the sun (416) of the second plane of gear of the Ravigneaux
planetary (411) is linked to the carrier of the variator (421). In
some embodiments, the sun (416) is connected to the housing in CVT
mode by applying brake (414). In some embodiments, in IVT/CVT mode,
the ring of the planetary system (411) is connected to the housing
by applying brake (415), thus letting the variator input ring (419)
and variator carrier (421) be both driven. In some embodiments,
this IVT/CVT mode lies in-between the IVT mode and the CVT mode
concerning speeds. In some embodiments, the overall ratio is the
product of the ravigneaux-like planetary ratio, the variator ratio
and the final drive ratio. In some embodiments, standstill, very
low vehicle speeds and reverse are achieved by the IVT mode of the
variator.
[0035] In some embodiments, the transition between the three modes
is simply done by engaging one clutch and releasing the other. In
some embodiments, this device is able to change continuously its
ratio to provide the best ratio achievable for the engine in
function of the objectives of consumption or power. In certain
instances, in a manual or automatic transmission, only some
predetermined and discrete ratios are available and an interruption
of the power transmission is needed to shift the ratio. In some
embodiments, the only interruption of power in this device is to
change modes. In some embodiments, another advantage is that spread
is higher than traditional gearboxes by having those three modes,
which improves efficiency. In some embodiments, another advantage
is that the ravigneaux-like planetary is a compact system. In some
embodiments, the apparatus allows for mode shifting between the
continuously variable (CVT) mode, infinitely variable (IVT) and the
combined IVT/CVT mode with a minimum number of brakes.
[0036] Concept 1f/
[0037] In an automobile 50, the CVT 503 is used to replace a
traditional transmission and is located between the engine 500 and
the differential 502. In some instances, a torsional damper 501 is
introduced between the engine 500 and ravigneaux-like planetary 511
as shown on FIG. 7. Configuration 1f/ (FIG. 7) uses a
ravigneaux-like planetary (511) before going to the variator (512).
In some embodiments, the variator output ring (520) is then linked
to the final drive (522) and differential. In some embodiments, the
configuration comprises three brake clutches, one for IVT mode
(513); one for CVT mode (514), and one for an IVT/CVT mode (515)
where the variator input ring (519) and the variator carrier (521)
are both driven. In some embodiments, the central part of that
configuration is the variator described above. In some embodiments,
a ball ramp on each side of the variator provides the clamping
force necessary to transfer the torque.
[0038] In some embodiments, the output (516) sun of the
ravigneaux-like planetary (511) is linked to the variator input
ring (519). In some embodiments, the output (516) sun is connected
to the housing in IVT mode by applying brake (513). In some
embodiments, the carrier (518) of that system (511) is then linked
to the carrier of the variator. In some embodiments, the carrier
(518) is connected to the housing in CVT mode by applying brake
(514). In some embodiments, in IVT/CVT mode, the ring (517) of the
planetary system (511) is connected to the housing by applying
brake (515), thus letting the variator input ring (519) and
variator carrier (521) be both driven. In some embodiments, this
IVT/CVT mode lies in-between the IVT mode and the CVT mode
concerning speeds. In some embodiments, the overall ratio is the
product of the ravigneaux-like planetary ratio, the variator ratio
and the final drive ratio. In some embodiments, standstill, very
low vehicle speeds and reverse are achieved by the IVT mode of the
variator.
[0039] In some embodiments, the transition between the three modes
is simply done by engaging one brake and releasing the others. In
some embodiments, this device is able to change continuously its
ratio to provide the best ratio achievable for the engine in
function of the objectives of consumption or power. In certain
instances, in a manual or automatic transmission, only some
predetermined and discrete ratios are available and an interruption
of the power transmission is needed to shift the ratio. In some
embodiments, the only interruption of power in this device is to
change modes. In some embodiments, another advantage is that spread
is higher than traditional gearboxes by having those three modes,
which improves efficiency. In some embodiments, another advantage
is that the ravigneaux-like planetary is a compact system. In some
embodiments, the apparatus allows for mode shifting between the
continuously variable (CVT) mode, infinitely variable (IVT) and the
combined IVT/CVT mode with a minimum number of brakes.
[0040] Concept 1g/
[0041] In an automobile 60, the CVT 603 is used to replace a
traditional transmission and is located between the engine 600 and
the differential 602. In some instances, a torsional damper 601 is
introduced between the engine 600 and a planetary gear 611 as shown
on FIG. 8. Configuration 1g/ (FIG. 8) uses a planetary gear set
(611) before going to the variator (612). In some embodiments, the
variator output is linked to an additional planetary (613). In some
embodiments, this planetary (613) is locked to turn with a 1:1
ratio by applying the clutch (616) to lock its sun and planet
carrier together. In some embodiments, a speed increase is achieved
by having more spread by applying the overdrive brake (617) to lock
the sun of the planetary to the ground. In some embodiments, the
ring of this planetary is then linked to the final drive and
differential. In some embodiments, the second ring of the variator
is linked to the planet carrier of the third planetary. In some
embodiments, the configuration comprises three brakes, one for IVT
mode (615) and one for CVT mode (614) and one for applying an
overdrive ratio (617). In some embodiments, the configuration
comprises a clutch (616) to bypass the overdrive planetary (613) by
putting it in a 1:1 ratio. In some embodiments, the central part of
that configuration comprises the variator described above. In some
embodiments, a ball ramp on each side of the variator provides the
clamping force necessary to transfer the torque.
[0042] In some embodiments, the ring of the input planetary is
linked to the variator input ring. In some embodiments, the ring of
the input planetary is connected to the housing in IVT mode by
applying the IVT brake (615). In some embodiments, the carrier of
the input planetary is connected to the housing in CVT mode by
applying the CVT brake (614). In some embodiments, the carrier of
the input planetary is linked to the carrier of the variator. In
some embodiments, the overall ratio is typically the product of the
input planetary ratio, the variator ratio, the output planetary
(613) ratio and the final drive ratio. In some embodiments,
standstill, very low vehicle speeds and reverse is achieved by the
IVT mode of the variator.
[0043] In some embodiments, the transition between the two modes
(CVT and IVT) is simply done by releasing one brake and closing the
other. Furthermore, the clutch (616) of the output planetary might
be used to select a ratio 1:1 in the output planetary. And the
Overdrive brake might be selected to provide an overdrive ratio. At
any moment only one of these overdrive brake and direct drive
clutch has to be engaged. The transition between these two
additional ratios is simply done by releasing one and engaging the
other. In some embodiments, this device is able to change
continuously its ratio to provide the best ratio achievable for the
engine in function of the objectives of consumption or power. In
certain instances, in a manual or automatic transmission, only some
predetermined and discrete ratios are available and an interruption
of the power transmission is needed to shift the ratio. In certain
instances, the only interruption of power in this device is to
change modes. Other advantages include, but are not limited to: a
small final drive (in one step, not needing a countershaft) and
cost effectiveness of the system. In some embodiments, spread is
higher than traditional gearboxes by adding the third planetary,
which improves global efficiency of the vehicle. In some
embodiments, the apparatus allows for mode shifting between the
continuously variable (CVT) mode and infinitely variable (IVT) mode
with a minimum number of brakes.
[0044] Embodiments of the variable transmission described herein or
that would be obvious to one of skill in the art upon reading the
disclosure herein are contemplated for use in a variety of vehicle
drivelines. For non-limiting example, the variable transmissions
disclosed herein may be used in bicycles, mopeds, scooters,
motorcycles, automobiles, electric automobiles, trucks, sport
utility vehicles (SUV's), lawn mowers, tractors, harvesters,
agricultural machinery, all-terrain vehicles (ATV's), jet skis,
personal watercraft vehicles, airplanes, trains, helicopters,
buses, forklifts, golf carts, motorships, steam powered ships,
submarines, space craft, or other vehicles that employ a
transmission.
[0045] While the figures and description herein are directed to
ball-type variators (CVTs), alternate embodiments are contemplated
another version of a variator (CVT), such as a Variable-diameter
pulley (VDP) or Reeves drive, a toroidal or roller-based CVT
(Extroid CVT), a Magnetic CVT or mCVT, Ratcheting CVT, Hydrostatic
CVTs, Naudic Incremental CVT (iCVT), Cone CVTs, Radial roller CVT,
Planetary CVT, or any other version CVT.
[0046] While preferred embodiments of the present invention have
been shown and described herein, it will be obvious to those
skilled in the art that such embodiments are provided by way of
example only. Numerous variations, changes, and substitutions will
now occur to those skilled in the art without departing from the
invention. It should be understood that various alternatives to the
embodiments of the invention described herein may be employed in
practicing the invention. It is intended that the following claims
define the scope of the invention and that methods and structures
within the scope of these claims and their equivalents be covered
thereby.
* * * * *