U.S. patent application number 15/929977 was filed with the patent office on 2021-12-02 for sandwiched gear train arrangement for multiple electric motor mixed-speed continuous power transmission.
This patent application is currently assigned to Allison Transmisson, Inc.. The applicant listed for this patent is Allison Transmission, Inc.. Invention is credited to Arthur L. McGrew, JR., Isaac Mock, George S. Pelton, James Allen Raszkowski.
Application Number | 20210372505 15/929977 |
Document ID | / |
Family ID | 1000004913240 |
Filed Date | 2021-12-02 |
United States Patent
Application |
20210372505 |
Kind Code |
A1 |
McGrew, JR.; Arthur L. ; et
al. |
December 2, 2021 |
SANDWICHED GEAR TRAIN ARRANGEMENT FOR MULTIPLE ELECTRIC MOTOR
MIXED-SPEED CONTINUOUS POWER TRANSMISSION
Abstract
An electric powertrain includes a first electric motor that has
an uninterrupted connection with a drive shaft of a vehicle. The
electric powertrain further includes a first gear train that has an
interruptible connection with the drive shaft. In one form, this
interruptible connection includes a second carrier and a clutch
engagement member. The electric powertrain further includes a sun
gear in the form of a ring gear and planet gears in the form of a
first output shaft. To provide a compact configuration, the first
electric motor and the first gear train are sandwiched between the
sun gear and the planet gears.
Inventors: |
McGrew, JR.; Arthur L.;
(Indianapolis, IN) ; Mock; Isaac; (Martinsville,
IN) ; Pelton; George S.; (Indianapolis, IN) ;
Raszkowski; James Allen; (Indianapolis, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Allison Transmission, Inc. |
Indianapolis |
IN |
US |
|
|
Assignee: |
Allison Transmisson, Inc.
Indianapolis
IN
|
Family ID: |
1000004913240 |
Appl. No.: |
15/929977 |
Filed: |
June 1, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16H 2200/2007 20130101;
B60Y 2200/91 20130101; F16H 3/724 20130101; B60K 1/02 20130101;
B60K 17/08 20130101; F16H 2200/2066 20130101; F16H 2200/2082
20130101; F16H 2200/2094 20130101; F16H 2200/2064 20130101; B60Y
2400/427 20130101; F16H 2200/201 20130101; F16H 2200/0021 20130101;
B60Y 2400/73 20130101; B60K 17/02 20130101 |
International
Class: |
F16H 3/72 20060101
F16H003/72; B60K 1/02 20060101 B60K001/02; B60K 17/02 20060101
B60K017/02; B60K 17/08 20060101 B60K017/08; B60K 6/365 20060101
B60K006/365; B60K 6/383 20060101 B60K006/383; B60K 6/387 20060101
B60K006/387 |
Claims
1. A powertrain system, comprising: a first gear train; a first
electric motor connected to an output via the first gear train,
wherein the first electric motor has an uninterrupted connection to
the output, wherein the uninterrupted connection is a mechanical
linkage that lacks a break in continuity; a second gear train; a
second electric motor connected to the output via the second gear
train; wherein the first electric motor and the second electric
motor are sandwiched between the first gear train and the second
gear train; wherein the first electric motor and the second
electric motor lack any gear train therebetween; wherein power is
supplied to the output solely through the first and second electric
motors; a clutch, wherein the clutch is configured to selectively
connect the second electric motor to the first electric motor;
wherein clutch is movable between at least a neutral position, a
first range position, and a second range position; wherein the
clutch at the neutral position disconnects the second electric
motor from the first electric motor; wherein the clutch at the
first range position increases tonrque supplied from the second
electric motor; and wherein the clutch at the second range position
decreases torque suppled from the second electric motor.
2. (canceled)
3. The powertrain system of claim 1, wherein the second electric
motor has an interruptible connection to the output.
4. The powertrain system of claim 3, wherein the interruptible
connection includes the clutch configured to couple the second
electric motor to the output.
5. The powertrain system of claim 4, wherein the clutch is a
positive clutch.
6. The powertrain system of claim 4, wherein the clutch is a dog
Clutch.
7. The powertrain system of claim 4, wherein the clutch is located
between the first electric motor and the second electric motor.
8. The powertrain system of claim 4, wherein the clutch is located
downstream of the first electric motor and the second electric
motor at the output.
9. The powertrain system of claim 1, wherein the second gear train
is located upstream from the first electric motor and the second
electric motor.
10. The powertrain system of claim 9, further comprising: a
Selectable One-Way Clutch (SOWC) is located upstream from the first
electric motor and the second electric motor at the second gear
train.
11. The powertrain system of claim 9, wherein the second electric
motor is located upstream relative to the first electric motor.
12. The powertrain system of claim 1, wherein the first gear train
is located upstream from the first electric motor and the second
electric motor.
13. The powertrain system of claim 12, further comprising: a
Selectable One-Way Clutch (SOWC) is located upstream of the first
electric motor and the second electric motor at the first gear
train.
14. The powertrain system of claim 12, wherein the first electric
motor is located upstream relative to the second electric
motor.
15. The powertrain system of claim 1, wherein the first gear train
includes a first planetary gear.
16. The powertrain system of claim 1, wherein the first and second
electric motors rotate about a common axis of rotation.
17. A powertrain system, comprising: a first gear train; a first
electric motor connected to an output via the first gear train; a
second gear train; a second electric motor connected to the output
via the second gear train; wherein the first electric motor has an
uninterrupted connection to the output and the second electric
motor has an interruptible connection to the output; wherein the
second gear train is located upstream from the first electric motor
and the second electric motor; wherein the uninterrupted connection
is a mechanical linkage that lacks a break in continuity; wherein
the interruptible connection includes a clutch disposed between the
firsy electric motor and the second electric motor: wherein die
clutch is a dog clutch; wherein the power is supplied to the output
solely through the first and second electric motors; and wherein
the first electric motor and the second electric motor lack any
gear train therebetween.
18. The powertrain system of claim 17, wherein the interruptible
connection includes a clutch configured to couple the second
electric motor to the output.
19. The powertrain system of claim 17, wherein the first electric
motor and the second electric motor are sandwiched between a first
gear train and a second gear train.
20. The powertrain system of claim 19, further comprising: a
Selectable One-Way Clutch (SOWC) is located upstream from the first
electric motor and the second electric motor at the second gear
train.
21. A powertrain system, comprising: a first gear train; a first
electric motor connected to an output via the first gear train; a
second gear train; a second electric motor connected to the output
via the second gear train; wherein the first electric motor has an
uninterrupted connection to the output and the second electric
motor has an interruptible connection to the output; wherein the
first gear train is located upstream from the first electric motor
and the second electric motor; wherein the uninterrupted to
connection is a mechanical linkage that lacks a break in
continuity; wherein the interruptible connection includes a clutch
configured to couple the second electric motor to the output;
wherein the clutch is a dog clutch; a Selectable One-Way Clutch
(SOWC) is located upstream of the firsrt electric motor and the
second electric motor at the first gear train; wherein the first
electric motor is located upstream relative to the second electric
motor; wherein the power is supplied to the output solely through
the first and second electric motors; and wherein the first
electric motor and the second electric motor lack any gear train
therebetween.
22. The powertrain system of claim 21, wherein the interruptible
connection includes a clutch configured to couple the second
electric motor to the output.
23. The powertrain system of claim 21, wherein the first electric
motor and the second electric motor are sandwiched between a first
gear train and a second gear train.
24. The powertrain system of claim 23, further comprising: a
Selectable One-Way Clutch (SOWC) is located upstream of the first
electric motor and the second electric motor at the first gear
train.
25. The powertrain system of claim 23, wherein the first electric
motor is located upstream relative to the second electric
motor.
26. The powertrain system of claim 1, wherein: the first electric
motor and the second electric motor are different from one another;
the first electric motor is a high speed motor with a rated
operating speed of at least 5,000 rpm; and the second electric
motor is a low speed motor with a rated operating speed of less
than 5,000 rpm.
27. The powertrain system of claim 15, wherein the second gear
train includes a second planetary gear.
28. The powertrain system of claim 27, further comprising: a first
output shaft connected to the first electric motor; wherein the
first output shaft is connected to the first planetary gear;
wherein the second planetary gear includes a sun gear, a ring gear,
and one or more planet gears engaged between the sun gear and the
ring gear; wherein second gear train includes a first range member
connected to the planet gears of the second planetary gear; a
second output shaft connected to the second electric motor; wherein
the second output shaft has a second range member; wherein the
clutch at the first range position engages the first range member
to increase the torque from the second electric motor; and wherein
the clutch at the second range position engages the second range
member to reduce the torque from the second electric motor.
29. The powertrain system of claim 17, further comprising: a first
output shaft connected to the first electric motor; a second output
shaft connected to the second electric motor; a third output shaft;
wherein the first output shaft and the second output shaft are
hollow; wherein the third output shaft extends in a concentric
manner inside the first output shaft and the second output shaft;
wherein the first gear train includes a first planetary gear;
wherein the second gear train includes a second planetary gear; and
wherein the clutch is configured to selectively connect the first
output shaft to the second output shaft.
30. The powertrain system of claim 21, wherein: the first gear
train includes a first planetary gear; the second gear train
includes a second planetary gear; the interruptible connection
includes a clutch configured to couple the second electric motor to
the output; the clutch is moveable between at least a neutral
position, a first range position, and a second range position; the
clutch at the neutral position disconnects the second electric
motor from the first electric motor; and the clutch at the first
range position engages the second planetary gear to increase torque
from the second electric motor.
Description
BACKGROUND
[0001] There has recently been an increased interest in hybrid and
electric vehicles. However, the recent developments have mostly
been related to the consumer passenger vehicle market. The same
technology has not yet been made available in the commercial
vehicle marketplace. The current electric motors used in consumer
vehicles are generally not able to be easily retrofitted into
commercial vehicles. Retrofitting the electric motors into the
powertrain would, in most cases, require a full redesign of the
powertrain components. Furthermore, there is the issue of the loss
of power during a shift in an electric vehicle. This issue would be
most prevalent in a heavy commercial vehicle as the loss of power
will result in vehicular deceleration that would be readily
perceptible by the driver.
[0002] Thus, there is a need for improvement in this field.
SUMMARY
[0003] A multiple electric motor system has been developed to
address the issues mentioned above as well as other issues. In one
form, the system includes dual electric motors that provide power
to an output such as a driveshaft of a vehicle. One of the electric
motors ("A"), which will be referred to as the "first motor" for
our purposes, is always connected to the output drive shaft in
order to continuously provide power for propelling the vehicle. In
other words, the first electric motor (A) has an uninterrupted
connection with the output. The system further includes a second
electric motor ("B") that intermittently applies torque to the
output shaft. In one variation, this intermittent connection
between the second electric motor (B) and the output includes at
least one clutch. The clutch engages and disengages the second
electric motor (B) with the output shaft.
[0004] To address the issue of retrofit due to space constraints,
the first electric motor (A) and the second electric motor (B) are
sandwiched between the first gear train and the second gear train.
To put this differently, one of the gear trains may be located
upstream of both motors while the other may be located downstream
from both motors, where upstream is defined as opposite the
direction of power transmission and downstream is defined as in the
direction of power transmission. Additionally, there may be a dog
clutch located between the first and second electric motors. This
clutch will serve to selectively couple the first and second output
shafts and allow the second electric motor to contribute to the
output.
[0005] The sandwiched configuration allows for the overall size of
the transmission to be reduced. This reduction in size will allow
for the transmission to be retrofitted into commercial vehicles
without the need for a major redesign in the powertrain
configuration.
[0006] Aspect 1 generally concerns a system that includes a first
electric motor connected to an output and a second electric motor
connected to the output.
[0007] Aspect 2 generally concerns the system of any previous
aspect in which the first electric motor and the second electric
motor are sandwiched between a first gear train and a second gear
train.
[0008] Aspect 3 generally concerns the system of any previous
aspect in which the first electric motor and the second electric
motor both have an interruptible connection to the output.
[0009] Aspect 4 generally concerns the system of any previous
aspect in which the first electric motor has an uninterrupted
connection to the output and the second electric motor has an
interruptible connection to the output.
[0010] Aspect 5 generally concerns the system of any previous
aspect in which the interruptible connection includes a clutch
configured to couple the second electric motor to the output.
[0011] Aspect 6 generally concerns the system of any previous
aspect in which the clutch includes a positive clutch.
[0012] Aspect 7 generally concerns the system of any previous
aspect in which the clutch has an actuator and a Selectable One-Way
Clutch (SOWC).
[0013] Aspect 8 generally concerns the system of any previous
aspect in which the clutch is located between the first electric
motor and the second electric motor.
[0014] Aspect 9 generally concerns the system of any previous
aspect in which the clutch is located downstream of the first
electric motor and the second electric motor at the output.
[0015] Aspect 10 generally concerns the system of any previous
aspect in which the second gear train is located upstream from the
first electric motor and the second electric motor.
[0016] Aspect 11 generally concerns the system of any previous
aspect in which the Selectable One-Way Clutch (SOWC) is located
upstream from the first electric motor and the second electric
motor at the second gear train.
[0017] Aspect 12 generally concerns the system of any previous
aspect in which the second electric motor is located upstream
relative to the first electric motor.
[0018] Aspect 13 generally concerns the system of any previous
aspect in which the first gear train is located upstream from the
first electric motor and the second electric motor.
[0019] Aspect 14 generally concerns the system of any previous
aspect in which the Selectable One-Way Clutch (SOWC) is located
upstream of the first electric motor and the second electric motor
at the first gear train.
[0020] Aspect 15 generally concerns the system of any previous
aspect in which the first electric motor is located upstream
relative to the second electric motor.
[0021] Aspect 16 generally concerns the system of any previous
aspect in which the first gear train includes a planetary gear.
[0022] Aspect 17 generally concerns the system of any previous
aspect in which the first and second electric motors rotate about a
common axis of rotation.
[0023] Aspect 18 generally concerns a method of operating the
system of any previous aspect.
[0024] Further forms, objects, features, aspects, benefits,
advantages, and embodiments of the present invention will become
apparent from a detailed description and drawings provided
herewith.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a diagrammatic view of a vehicle.
[0026] FIG. 2 is a diagrammatic view of an example of an electric
powertrain that can be used in the vehicle of FIG. 1.
[0027] FIG. 3 is a diagrammatic view of another example of an
electric powertrain that can be used in the vehicle of FIG. 1.
[0028] FIG. 4 is a cross-sectional view of the electric powertrain
from FIG. 3.
[0029] FIG. 5 is a diagrammatic view of a further example of a
transmission that can be used in the vehicle of FIG. 1.
DETAILED DESCRIPTION OF SELECTED EMBODIMENTS
[0030] For the purpose of promoting an understanding of the
principles of the invention, reference will now be made to the
embodiments illustrated in the drawings and specific language will
be used to describe the same. It will nevertheless be understood
that no limitation of the scope of the invention is thereby
intended. Any alterations and further modifications in the
described embodiments, and any further applications of the
principles of the invention as described herein, are contemplated
as would normally occur to one skilled in the art to which the
invention relates. One embodiment of the invention is shown in
great detail, although it will be apparent to those skilled in the
relevant art that some features that are not relevant to the
present invention may not be shown for the sake of clarity.
[0031] The reference numerals in the following description have
been organized to aid the reader in quickly identifying the
drawings where various components are first shown. In particular,
the drawing in which an element first appears is typically
indicated by the left-most digit(s) in the corresponding reference
number. For example, an element identified by a "100" series
reference numeral will likely first appear in FIG. 1, an element
identified by a "200" series reference numeral will likely first
appear in FIG. 2, and so on.
[0032] A vehicle 100 according to one example is illustrated in
FIG. 1. As shown, the vehicle 100 includes at least one powertrain
system 105, at least one controller 110, and at least one Energy
Storage System ("ESS") 115 configured to supply power to the
powertrain system 105. The powertrain system 105, controller 110,
and ESS 115 are operatively connected together so as to communicate
with one another via at least one Controller Area Network ("CAN")
120. The controller 110 is configured to control the operation of
one or more systems and/or other components of the vehicle 100 such
as the powertrain system 105 and ESS 115. The powertrain system 105
has an output or drive shaft 125 that transfers mechanical power
from the powertrain system 105 to a propulsion system 130. In the
illustrated example, the propulsion system 130 includes one or more
wheels 135, but the propulsion system 130 in further examples can
include other types of propulsion devices like continuous track
systems. One or more power cables 140 transfer electrical power
between the powertrain system 105 and the ESS 115.
[0033] The powertrain system 105 is designed to electrically propel
the vehicle 100 in an efficient manner. As will be explained in
greater detail below, the powertrain system 105 is designed to
power heavy-duty commercial and/or military grade vehicles such as
buses, garbage trucks, delivery trucks, fire trucks, and
semi-trailers. The powertrain system 105 is designed to
electrically power vehicles 100 with a class group rating of at
least four (4) according to the US Department of Transportation
Federal Highway Administration (FHWA) classification rule set. In
one form, the powertrain system 105 is configured to move at least
40,000 pound (18,144 Kg) passenger vehicles like buses. The
powertrain system 105 has a unique, compact centerline design that
allows the powertrain system 105 to be easily retrofitted into
pre-existing vehicle chassis designs and/or conventional
drivetrains with minimal changes to the other parts of the vehicle
100 like the braking and suspension systems. This in turn allows
existing internal combustion type vehicles to be readily
reconfigured as fully electric vehicles. Moreover, the centerline
design of the powertrain system 105 reduces gear loss and other
power losses so as to make the vehicle 100 more power efficient
which in turn can improve driving range and/or reduce weight of
other components such as the ESS 115.
[0034] FIG. 2 shows an electric powertrain 200 that can be used in
the electric powertrain system 105. The electric powertrain 200
includes a first electric motor 210 with a first inverter 212 and a
second electric motor 215 with a second inverter 217. In this
illustrated example, the first electric motor 210 and second
electric motor 215 are not the same type of motor such that the
first electric motor 210 and second electric motor 215 are not
interchangeable with one another. By using different types of
motors, which can have different speed, torque, and/or power
characteristics, the efficiency and power characteristics of the
electric powertrain 200 can be enhanced. In other words, one of the
motors can compensate for the deficiencies of the other under
different operational demands. For instance, when the electric
powertrain 200 is dealing with a load that requires high torques at
low speeds, a low-speed, high-torque motor can provide most (if not
all) of the power, and the corresponding high-speed, low-torque
motor can provide less power. When the conditions reverse to a low
torque, high speed situation, the workloads of the motors can
reverse such that the high-speed, low-torque motor provides more
(or all) of the power, and the low speed, high torque motor
provides less power.
[0035] As shown, the first electric motor 210 is located upstream
of the drive shaft 125 relative to the second electric motor 215.
In the illustrated example, the first electric motor 210 is a high
speed electric motor, and the second electric motor 215 is a low
speed electric motor. In one version, the first electric motor 210
is a high speed electric motor having a rated operating speed of at
least 5,000 rpm, and the second electric motor 215 is a low speed
electric motor having a rated operating speed of less than 5,000
rpm. The first electric motor 210 in one version has a rated
operating speed of at least 10,600 rpm, a rated peak power of at
least 250 hp, a rated continuous power of at least 150 hp, a rated
continuous torque of at least 240 lb-ft, and a rated peak torque of
at least 310 lb-ft. In this version, the second electric motor 215
has a rated operating speed of at most 4,500 rpm, a rated peak
power of at least 250 hp (600 Volts DC), a rated continuous power
of at least 133 hp (600 Volts DC), a rated continuous torque of at
least 320 lb-ft, and a rated peak torque of at least 735 lb-ft. The
speed of the second electric motor 215 in one form is limited to a
maximum speed of 3,500 rpm during operation.
[0036] The first inverter 212 and second inverter 217 convert DC
from the ESS 115 to AC in order to power the first electric motor
210 and second electric motor 215, respectively. The first electric
motor 210 and second electric motor 215 can also act as generators
such as during regenerative braking. In such a situation, the first
inverter 212 and second inverter 217 act as rectifiers by
converting the AC electrical power from the first electric motor
210 and second electric motor 215, respectively, to DC power that
is supplied to the ESS 115. In the illustrated example, the first
inverter 212 and second inverter 217 include combined
inverter-rectifiers that at least convert DC to AC and AC to
DC.
[0037] As can be seen in FIG. 2, a transmission 205 further
includes a first gear train 220. The first gear train 220 is
located at the output end of the first electric motor 210 which is
located on the end of the electric powertrain 200 that is opposite
to the drive shaft 125. The first electric motor 210 and second
electric motor 215 are sandwiched between the first gear train 220
and second gear train 270. Among other things, this sandwiched
relationship simplifies assembly and enhances performance. For
instance, this sandwiched configuration in which the first electric
motor 210 and second electric motor 215 are located between the
first gear train 220 and second gear train 270 aids in retrofitting
the powertrain system 105 to pre-existing vehicle designs. With the
gearing as the ends, multiple electric powertrains 200 can be daisy
chained together so as to share gearing between the electric
powertrains 200. Moreover, all or some of the equipment related to
the motors can be shared or concentrated in one area. The first
electric motor 210 and second electric motor 215 can also be packed
closely together so as to conserve space. The first gear train 220
includes a first planetary gear 225. As depicted, the first
planetary gear 225 has a sun gear 230 that is attached to the first
electric motor 210, one or more planet gears 235 engaged to orbit
around the sun gear 230, and a ring gear 240 that surrounds the
planet gears 235. The planet gears 235 engage both the sun gear 230
and ring gear 240. The planet gears 235 are secured to a first
carrier 245.
[0038] The electric powertrain 200 further has a first output shaft
250 that connects the first carrier 245 of the first planetary gear
225 to the drive shaft 125. Proximal to the drive shaft 125, the
clutch engagement member 295 extends radially from the first output
shaft 250. As illustrated, the first output shaft 250 extends in a
longitudinal direction through the first electric motor 210, second
electric motor 215, and a second output shaft 277. The first output
shaft 250 extends in a concentric manner with the second output
shaft 277. The first electric motor 210 and second electric motor
215 in one example are respectively secured to the first planetary
gear 225 and second output shaft 277 via spline type connections.
The first electric motor 210 can have an uninterrupted connection
to the drive shaft 125 via the first planetary gear 225 and first
output shaft 250, if so desired.
[0039] The transmission 205 further includes a Selectable One-Way
Clutch ("SOWC") 255 that is able to engage and disengage the ring
gear 240 such that ring gear 240 is able to be stationary or
rotate. In the illustrated example, the SOWC 255 includes a clutch
engagement member 260 configured to engage the ring gear 240 of the
first planetary gear 225 and a clutch actuator 265 that selectively
engages the clutch engagement member 260 with the ring gear 240 to
provide torque from the first electric motor 210 to the first
output shaft 250. The clutch actuator 265 is operatively coupled to
the controller 110 so that the controller 110 is able to control
the operation of the SOWC 255.
[0040] When the clutch actuator 265 of the SOWC 255 disengages the
clutch engagement member 260 from the ring gear 240, the ring gear
240 is able to rotate or orbit around the sun gear 230 in the first
planetary gear 225. With the ring gear 240 in this disengaged state
in which the ring gear 240 is able to move, the first carrier 245
remains generally stationary even when the first electric motor 210
rotates or applies torque to the sun gear 230 of the first
planetary gear 225. Consequently, torque is not transferred from
the first electric motor 210 to the drive shaft 125. In another
embodiment, when torque from the first electric motor 710 is not
required, the first electric motor 710 can be shut down. This
prevents the rotation of the first electric motor 710. As a result,
no torque is provided to the drive shaft 125. On the other hand,
when the controller 110 via the clutch actuator 265 engages the
clutch engagement member 260 with the ring gear 240, relative
movement of the ring gear 240 is prevented. Having the ring gear
240 fixed allows the first carrier 245 to rotate as the first
electric motor 210 rotates the sun gear 230 which in turn allows
torque to be transferred from the first electric motor 210 to the
drive shaft 125 along the first output shaft 250. The first
electric motor 210 is again a high speed motor. The first planetary
gear 225 reduces the output speed of the first electric motor 210
such that the speed of the first output shaft 250 can generally
match the speed of the lower speed, second electric motor 215, if
needed.
[0041] A second gear train 270 and a clutch 285 in the electric
powertrain 200 operate in a similar fashion as described before.
The controller 110 via a clutch actuator 292 shifts a dog clutch
290 between neutral, first range, and second range positions so
that the second electric motor 215 is able to provide different
torques (or not) to a clutch engagement member 295 that are
combined with the torque from the first electric motor 210 at the
drive shaft 125. When the dog clutch 290 is in a neutral position,
the second electric motor 215 does not supply power to the drive
shaft 125. In such a case, the first electric motor 210 can supply
all of the power to the drive shaft 125, if required. Once more,
the first electric motor 210 can also act as a generator during
regenerative braking so as to recharge the ESS 115. The dog clutch
290 engages a first range member 297 to place the clutch 285 in the
first range position where the second electric motor 215 is able to
provide higher torques through a second planetary gear 275
connected by a second carrier 280 and first range member 297 to the
drive shaft 125. The dog clutch 290 shifts to the second range
position by engaging a second range member 299. At the second range
position, the second electric motor 215 provides a torque that is
lower than when at the first range position, but the speed is
higher. While the first electric motor 210 is a high speed motor,
the output speed of the first electric motor 210 is reduced by the
first planetary gear 225, and the second electric motor 215 is a
low speed motor such that the first gear train 220 is not required
to reduce the speed of the output from the electric powertrain 200.
This configuration in turn allows the use of two different, or
non-interchangeable, motors that have different power profiles such
that the first electric motor 210 and second electric motor 215
cumulatively can operate more efficiently.
[0042] FIG. 3 shows a diagram of another example of an electric
powertrain 300 that can be used in the vehicle 100 of FIG. 1, and
FIG. 4 shows a cross-sectional view of the electric powertrain 300.
The electric powertrain 300 shares a number of components and
functions in common with the one described before. For the sake of
brevity as well as clarity, these common features will not be
described in great detail below, but please refer to the previous
discussions of these features.
[0043] As depicted, the electric powertrain 300 includes a multiple
motor continuous power transmission 302. The transmission 302 of
the electric powertrain 300 includes a first electric motor 305
with a first inverter 306 and a second electric motor 307 with a
second inverter 308. The first inverter 306 is electrically
connected between the ESS 115 and the first electric motor 305, and
the second inverter 308 is electrically connected between the ESS
115 and the second electric motor 307. The first inverter 306 and
second inverter 308 convert the direct current (DC) from the ESS
115 to alternating current (AC) in order to power the first
electric motor 305 and second electric motor 307, respectively. The
first electric motor 305 and second electric motor 307 can also act
as generators such as during regenerative braking. In such a
situation, the first inverter 306 and second inverter 308 convert
the AC electrical power from the first electric motor 305 and
second electric motor 307, respectively, to DC power that is
supplied to the ESS 115. In one example, the first electric motor
305 and second electric motor 307 are the same type of electric
motor such that both motors generally provide the same speed and
torque output within normal manufacturing tolerances. The first
electric motor 305 and second electric motor 307 in one form are
interchangeable with one another. The first electric motor 305 and
second electric motor 307 in one form are both high speed electric
motors. In one specific example, the first electric motor 305 and
second electric motor 307 are the same type of high speed electric
motor having rated speeds of at least 5,000 rpm, and more
particularly, the first electric motor 305 and second electric
motor 307 each has a rated speed of at least 10,600 rpm, a rated
peak power of at least 390 hp, a rated continuous power of at least
150 hp, a rated continuous torque of at least 240 lb-ft, and a
rated peak torque of at least 310 lb-ft.
[0044] As can be seen in FIGS. 3 and 4, the electric powertrain 300
includes a first gear train 309 and a second gear train 310. The
first gear train 309 is located at the output end of the first
electric motor 305 and is proximal to the drive shaft 125. The
first gear train 309 includes a first planetary gear 397 with a sun
gear 390. Located opposite the second electric motor 307, on the
other side of the drive shaft 125 is the second gear train 310. The
second gear train 310 includes a second planetary gear 315 with a
second carrier 320.
[0045] In the illustrated example, the transmission 302 includes a
first output shaft 325, a second output shaft 330, and a third
output shaft 335 that extend in a longitudinal direction in the
electric powertrain 300. The first output shaft 325 and second
output shaft 330 are hollow so as to receive the third output shaft
335. The third output shaft 335 extends in a concentric manner
inside the first output shaft 325 and second output shaft 330. The
second gear train 310 and second planetary gear 315 in one example
are respectively secured to the first output shaft 325 and second
output shaft 330 via a spline type connection of the types
described before.
[0046] As shown, the first output shaft 325 and third output shaft
335 are directly connected to the sun gear 390 of the first
planetary gear 397. The second output shaft 330 has an
interruptible connection with the first output shaft 325 through a
first clutch 340 that selectively connects the second output shaft
330 to the first output shaft 325. To provide a compact design, the
first clutch 340 is located or sandwiched in between the first
electric motor 305 and second electric motor 307. In the
illustrated example, the first clutch 340 includes a single
position type dog clutch 345, but other types of clutches can be
used in other variations. The dog clutch 345 includes a clutch
collar 350 and a clutch actuator 355 that is configured to move the
clutch collar 350 in a longitudinal direction to engage and
disengage the second output shaft 330 from the first output shaft
325. The clutch actuator 355 of the first clutch 340 is operatively
connected to the controller 110 so that the controller 110 is able
to control the first clutch 340. In the depicted example, the first
output shaft 325 has a clutch engagement member 360 and the second
output shaft 330 has a range member 365, and the clutch collar 350
of the dog clutch 345 selectively engages and disengages the range
member 365 of the second output shaft 330 from the clutch
engagement member 360 of the first output shaft 325. In other
words, the first output shaft 325 and second output shaft 330 form
an interruptible split shaft design that can be selectively
connected together so that the torque from the second gear train
310 and second planetary gear 315 can be combined together.
[0047] At the end opposite the range member 365, the second output
shaft 330 is connected to the second planetary gear 315. Like in
the other examples, the second planetary gear 315 includes the sun
gear 390, one or more planet gears 392, and a ring gear 395
generally arranged in a concentric manner relative to one another.
The second output shaft 330 in the depicted example is connected to
the second planetary gear 315 at the sun gear 390. The second
planetary gear 315 is in turn connected to the third output shaft
335 through the second carrier 320. Through the second carrier 320,
the second planetary gear 315 is able to provide torque to the
first output shaft 325 which in turn is provided to the sun gear
390 of the first gear train 309.
[0048] The transmission 302 further includes a second clutch 370
that engages the second planetary gear 315. In the illustrated
example, the second clutch 370 includes a Selectable One-Way Clutch
("SOWC") 375. The SOWC 375 includes a clutch engagement member 380
configured to engage the ring gear 395 of the second planetary gear
315 and a clutch actuator 385 that selectively engages the clutch
engagement member 380 with the ring gear 395 to change the gear
ratio for the power supplied by the second planetary gear 315 or
disconnects the second electric motor 307. The clutch actuator 385
of the SOWC 375 is operatively connected to the controller 110 so
that the controller 110 is able to control the second clutch 370.
By controlling the operation of the first clutch 340 and second
clutch 370, the controller 110 is able to change and control the
speed and torque supplied by the second planetary gear 315 to the
first gear train 309. In one form, the first clutch 940 and the
second clutch 970 work together to attain the first range position.
To attain the first range position, the SOWC 975 is engaged to the
ring gear 260 by actuation of the clutch actuator 985. At this
time, the first clutch 940 is disengaged from the clutch engagement
member 960 so that the first output shaft 925 and the second output
shaft 930 are disconnected. To attain the second range position,
the SOWC 975 is disengaged from the ring gear 260 by actuation of
the clutch actuator 985. This allows the ring gear 260 to
freewheel. At this time, the first clutch 940 is actuated by the
clutch actuator 955 to engage with the clutch engagement member
960. This connects the first output shaft 925 and the second output
shaft 930.
[0049] As should be recognized, the second gear train 310 in FIGS.
3 and 4 operates in a similar fashion to the first planetary gear
225 in FIG. 2. When the clutch engagement member 380 of the SOWC
375 engages the ring gear 395, the second gear train 310 reduces
the speed and increases the torque supplied to the third output
shaft 335 from the second electric motor 307. When the clutch
engagement member 380 is disengaged from the ring gear 395, no
torque is provided via the second gear train 310. To provide torque
from the second electric motor 307, the controller 110 via the dog
clutch 345 connects the range member 365 of the second output shaft
330 to the clutch engagement member 360 of the first output shaft
325. In these as well as other operational scenarios, the first
gear train 309 reduces the speed of the output provided by the
first electric motor 305 and/or second electric motor 307 which are
high speed motors.
[0050] FIG. 5 shows a diagram of another example of the powertrain
system 105 of FIG. 1. The powertrain system 105 shares a number of
components and functions in common with the ones described before
(see e.g., FIGS. 2 and 3). For the sake of brevity as well as
clarity, these common features will not be described in great
detail below, but please refer to the previous discussion.
[0051] As depicted, the powertrain system 105 includes a multiple
motor continuous power transmission 505. The transmission 505 of
the powertrain system 105 includes the first electric motor 210
with the first inverter 212 and the second electric motor 215 with
the second inverter 217. The first inverter 212 is electrically
connected between the ESS 115 and the first electric motor 210, and
the second inverter 217 is electrically connected between the ESS
115 and the second electric motor 215. The first inverter 212 and
second inverter 217 convert the direct current (DC) from the ESS
115 to alternating current (AC) in order to power the first
electric motor 210 and second electric motor 215, respectively. The
first electric motor 210 and second electric motor 215 can also act
as generators such as during regenerative braking. In such a
situation, the first inverter 212 and second inverter 217 convert
the AC electrical power from the first electric motor 210 and
second electric motor 215, respectively, to DC power that is
supplied to the ESS 115. In one example, the first electric motor
210 and second electric motor 215 are the same type of electric
motor such that both motors generally provide the same speed and
torque output within normal manufacturing tolerances. The first
electric motor 210 and second electric motor 215 in one form are
both high speed electric motors, and in another form, the first
electric motor 210 and second electric motor 215 are both low speed
electric motors. In alternative variations, the first electric
motor 210 and second electric motor 215 can be different such that
one for example is a high speed motor and the other is a low speed
motor.
[0052] The transmission 505 of the powertrain system 105 includes
the first gear train 309 of the type shown in FIG. 3, the second
gear train 270 of the type shown in FIG. 2, and a third gear train
510. The first gear train 309 is located downstream of the second
electric motor 215 and is proximal to the drive shaft 125. The
second gear train 270 is located just upstream from the first gear
train 309 sandwiched between the second electric motor 215 and the
first gear train 309. The third gear train 510 is located on the
opposite side of the first electric motor 210 and second electric
motor 215 where a first output shaft 515 of the transmission 505
meets the third gear train 510. The third gear train 510 includes a
third planetary gear 530 and a fourth planetary gear 535 which are
meshed and held in position by a third carrier 540. The third
carrier 540 is mounted to the transmission housing and does not
move. Located between the fourth planetary gear 535 and a second
clutch 525 is a first range member 555. The first range member 555
serves to engage the second clutch 525 when in the first range
positon. The third gear train 510 also has a second range member
550 which serves to engage the second clutch 525 when in the second
range position. Whether in the first or second range positon, the
third gear train 510 has a clutch engagement member 545 to engage
the second clutch 525 and transmit power through the first output
shaft 515. In the illustrated example, the first gear train 309 is
in the form of the first planetary gear 397 as shown in FIG. 3, the
second gear train 270 is in the form of the second planetary gear
275 as shown in FIG. 2, and the third gear train 510 is in the form
of the third planetary gear 530 and the fourth planetary gear 535.
The first electric motor 210 and second electric motor 215
respectively have the first output shaft 515 and a second output
shaft 520 for providing rotational mechanical power. In the
illustrated example, the second output shaft 520 is hollow such
that the first output shaft 515 is able to extend through the
second output shaft 520 in a concentric manner.
[0053] The second gear train 270 and clutch 285 in the powertrain
system 105 operate as follows. The controller 110 via the clutch
actuator 292 shifts the clutch 285 between neutral, first range,
and second range positions. This allows the second electric motor
215 to provide different output torques to the clutch engagement
member 295 which are then combined with the torque produced by the
first electric motor 210 through the third gear train 510 at the
drive shaft 125. When the clutch 285 is in the neutral position the
second electric motor 215 does not supply power to the drive shaft
125. In this case all of the output power is being supplied by the
first electric motor 210. To place the clutch 285 into the first
range positon the clutch actuator 292 moves the clutch 285 to
engage with the first range member 297. This allows the second
electric motor 215 to provide higher torques to the drive shaft
125. The second range position is achieved by having the clutch
actuator 292 move the clutch 285 to engage with the second range
member 299. In the second range position, the second electric motor
215 is able to provide less torque than in the first range
position, but the speed is higher. The first gear train 309 is made
up of the first planetary gear 397 and is connected to the drive
shaft 125 by the first carrier 399. The first gear train 309 serves
to reduce the speed of the output provided by the first electric
motor 210 and/or the second electric motor 215. The second gear
train 270 is not connected to a clutch and therefore is constantly
in use.
[0054] The third gear train 510 and the second clutch 525 operate
in a similar fashion to the second gear train 270 and clutch 285
described above. The controller 110 via a second clutch actuator
527 shifts the second clutch 525 between neutral, first range, and
second range positions. This allows the first electric motor 210 to
provide different output torques to the clutch engagement member
545 which are then sent through the first output shaft 515 to the
drive shaft 125. When the second clutch 525 is in the neutral
position, the torque runs through the first output shaft 515 to the
drive shaft 125 modified only by the first gear train 309. To place
the second clutch 525 into the first range positon, the second
clutch actuator 527 moves the second clutch 525 to engage with the
first range member 555. This allows the first electric motor 210 to
provide higher torques through a third planetary gear 530 and a
fourth planetary gear 535 which are connected by the third carrier
540. The second range position is achieved by having the second
clutch actuator 527 move the second clutch 525 to engage with the
second range member 550. In the second range position, the first
electric motor 210 provides less torque than in the first range
position, but the speed is higher.
[0055] Glossary of Terms
[0056] The language used in the claims and specification is to only
have its plain and ordinary meaning, except as explicitly defined
below. The words in these definitions are to only have their plain
and ordinary meaning. Such plain and ordinary meaning is inclusive
of all consistent dictionary definitions from the most recently
published Webster's dictionaries and Random House dictionaries. As
used in the specification and claims, the following definitions
apply to these terms and common variations thereof identified
below.
[0057] "About" with reference to numerical values generally refers
to plus or minus 10% of the stated value. For example if the stated
value is 4.375, then use of the term "about 4.375" generally means
a range between 3.9375 and 4.8125.
[0058] "And/Or" generally refers to a grammatical conjunction
indicating that one or more of the cases it connects may occur. For
instance, it can indicate that either or both of two stated cases
can occur. In general, "and/or" includes any combination of the
listed collection. For example, "X, Y, and/or Z" encompasses: any
one letter individually (e.g., {X}, {Y}, {Z}); any combination of
two of the letters (e.g., {X, Y}, {X, Z}, {Y, Z}); and all three
letters (e.g., {X, Y, Z}). Such combinations may include other
unlisted elements as well.
[0059] "Axis" generally refers to a straight line about which a
body, object, and/or a geometric figure rotates or may be conceived
to rotate.
[0060] "Clutch" generally refers to a device that engages and
disengages mechanical power transmission between two or more
rotating shafts or other moving components. In one example, one
shaft is typically attached to an engine, motor, or other power
source, which acts as the driving member, while the other shaft
(i.e., the driven member) provides output power for work. While the
motions involved are usually rotary motions, linear clutches are
also used to engage and disengage components moving with a linear
or near linear motion. The clutch components can for instance be
engaged and disengaged through mechanical, hydraulic, and/or
electrical actuation. The clutches can include positive type
clutches and friction type clutches. Wet type clutches are
typically immersed in a cooling lubrication liquid or other fluid,
and dry clutches are not bathed in such liquids. Some non-limiting
examples of clutches include cone clutches, centrifugal clutches,
torque limiter clutches, axial clutches, disc clutches, dog
clutches, and rim clutches, to name just a few.
[0061] "Contact" generally refers to a condition and/or state where
at least two objects are physically touching. For example, contact
requires at least one location where objects are directly or
indirectly touching, with or without any other member(s) material
in between.
[0062] "Controller" generally refers to a device, using mechanical,
hydraulic, pneumatic electronic techniques, and/or a microprocessor
or computer, which monitors and physically alters the operating
conditions of a given dynamical system. In one non-limiting
example, the controller can include an Allen Bradley brand
Programmable Logic Controller (PLC). A controller may include a
processor for performing calculations to process input or output. A
controller may include a memory for storing values to be processed
by the processor or for storing the results of previous processing.
A controller may also be configured to accept input and output from
a wide array of input and output devices for receiving or sending
values. Such devices include other computers, keyboards, mice,
visual displays, printers, industrial equipment, and systems or
machinery of all types and sizes. For example, a controller can
control a network or network interface to perform various network
communications upon request. The network interface may be part of
the controller, or characterized as separate and remote from the
controller. A controller may be a single, physical, computing
device such as a desktop computer or a laptop computer, or may be
composed of multiple devices of the same type such as a group of
servers operating as one device in a networked cluster, or a
heterogeneous combination of different computing devices operating
as one controller and linked together by a communication network.
The communication network connected to the controller may also be
connected to a wider network such as the Internet. Thus a
controller may include one or more physical processors or other
computing devices or circuitry and may also include any suitable
type of memory. A controller may also be a virtual computing
platform having an unknown or fluctuating number of physical
processors and memories or memory devices. A controller may thus be
physically located in one geographical location or physically
spread across several widely scattered locations with multiple
processors linked together by a communication network to operate as
a single controller. Multiple controllers or computing devices may
be configured to communicate with one another or with other devices
over wired or wireless communication links to form a network.
Network communications may pass through various controllers
operating as network appliances such as switches, routers,
firewalls or other network devices or interfaces before passing
over other larger computer networks such as the Internet.
Communications can also be passed over the network as wireless data
transmissions carried over electromagnetic waves through
transmission lines or free space. Such communications include using
WiFi or other Wireless Local Area Network (WLAN) or a cellular
transmitter/receiver to transfer data.
[0063] "Controller Area Network" or "CAN" generally refers to a
vehicle bus standard designed to allow microcontrollers, sensors,
and/or other devices to communicate with each other in applications
without necessarily a host computer. CAN systems include a
message-based protocol, designed originally for multiplex
electrical wiring within automobiles, but is also used in many
other contexts. A vehicle with a CAN system may normally, but not
always, includes multiple Electronic Control Units (ECUs) which can
be also called nodes. These ECUs can include Engine Control Modules
(ECMs) and Transmission Control Modules (TCMs) as well as other
control units such as for airbags, antilock braking/ABS, cruise
control, electric power steering, audio systems, power windows,
doors, mirror adjustment, battery and/or hybrid/electric recharging
systems, to name just a few. A CAN includes a multi-master serial
bus standard for connecting ECUs. The complexity of the ECU or node
can range from a simple Input/Output (I/O) device up to an embedded
computer with a CAN interface and software. The ECU or node can
also act as a gateway allowing a general purpose computer to
communicate over an interface, such as via a USB and/or Ethernet
port, to the devices on the CAN network. Each ECU usually, but not
always, includes a central processing unit, a CAN controller, and
transceiver. The CAN systems can for example include low speed CAN
(128 Kbps) under the ISO 11898-3 standard, high speed CAN (512Kbps)
under the ISO 11898-2 standard, CAN FD under the ISO 11898-1
standard, and single wire CAN under the SAE J2411 standard.
[0064] "Dog Clutch" generally refers to a type of positive clutch
that couples and decouples at least two rotating shafts or other
rotating mechanical components by an interference type connection.
The two parts of the clutch are designed such that one will push
the other, thereby causing both to rotate at the same speed with no
(or very minimal) slippage. Typically, but not always, one part of
the dog clutch includes a series of teeth or other protrusions that
are configured to mate with another part of the dog clutch that
includes corresponding recesses for receiving the teeth or
protrusions. Unlike friction clutches that allow slippage, dog
clutches are used where slip is undesirable and/or the clutch is
not used to control torque. Without slippage, dog clutches are not
affected by wear in the same manner as friction clutches.
[0065] "Downstream" generally refers to a direction or relative
location that is the same as where power flows in a system.
[0066] "Electric Motor" generally refers to an electrical machine
that converts electrical energy into mechanical energy. Normally,
but not always, electric motors operate through the interaction
between one or more magnetic fields in the motor and winding
currents to generate force in the form of rotation. Electric motors
can be powered by direct current (DC) sources, such as from
batteries, motor vehicles, and/or rectifiers, or by alternating
current (AC) sources, such as a power grid, inverters, and/or
electrical generators. An electric generator can (but not always)
be mechanically identical to an electric motor, but operate in the
reverse direction, accepting mechanical energy and converting the
mechanical energy into electrical energy.
[0067] "Energy Storage System" (ESS) or "Energy Storage Unit"
generally refers to a device that captures energy produced at one
time for use at a later time. The energy can be supplied to the ESS
in one or more forms, for example including radiation, chemical,
gravitational potential, electrical potential, electricity,
elevated temperature, latent heat, and kinetic types of energy. The
ESS converts the energy from forms that are difficult to store to
more conveniently and/or economically storable forms. By way of
non-limiting examples, techniques for accumulating the energy in
the ESS can include: mechanical capturing techniques, such as
compressed air storage, flywheels, gravitational potential energy
devices, springs, and hydraulic accumulators; electrical and/or
electromagnetic capturing techniques, such as using capacitors,
super capacitors, and superconducting magnetic energy storage
coils; biological techniques, such as using glycogen, biofuel, and
starch storage mediums; electrochemical capturing techniques, such
as using flow batteries, rechargeable batteries, and ultra
batteries; thermal capture techniques, such as using eutectic
systems, molten salt storage, phase-change materials, and steam
accumulators; and/or chemical capture techniques, such as using
hydrated salts, hydrogen, and hydrogen peroxide. Common ESS
examples include lithium-ion batteries and super capacitors.
[0068] "Gear Train" generally refers to a system of gears that
transmit power from one mechanical component to another. For
example, a gear train can include a combination of two or more
gears, mounted on rotating shafts, to transmit torque and/or power.
As one non-limiting example, the gear train for instance can
include a planetary gearset.
[0069] "High Speed Motor" generally refers to a motor that has a
rated operating speed of at least 5,000 rpm (revolutions per
minute) without the use of gear trains or other similar equipment
for changing speed.
[0070] "Integrally Formed" generally refers to being formed as or
fused into a single piece without needing some form of connection
or attachment.
[0071] "Interruptible Connection" generally refers to a mechanical
linkage between two mechanical components that has the ability to
break continuity during normal operation such that the components
can be mechanically disconnected and reconnected if so desired.
When disconnected, the components are unable to provide mechanical
power to one another. The interruptible connection can include
multiple components such as multiple shafts and gears that engage
with one another. The interruptible connection includes at least
one mechanism, such as a clutch, that is designed to disconnect and
reconnect the mechanical linkage between the components during
normal operation.
[0072] "Inverter" or "Power Inverter" generally refers to an
electronic device and/or circuitry that at least converts direct
current (DC) to alternating current (AC). Certain types of
inverters can further include a rectifier that converts AC to DC
such that the inverter and rectifier functions are combined
together to form a single unit that is sometimes referred to as an
inverter. The inverter can be entirely electronic or may be a
combination of mechanical devices, like a rotary apparatus, and
electronic circuitry. The inverter can further include static type
inverters that do not use moving parts to convert DC to AC.
[0073] "Lateral" generally refers to being situated on, directed
toward, or coming from the side. "Longitudinal" generally relates
to length or lengthwise dimension of an object, rather than
across.
[0074] "Low Speed Motor" generally refers to a motor that has a
rated operating speed of less than 5,000 rpm (revolutions per
minute) without the use of gear trains or other similar equipment
for changing speed.
[0075] "Means For" in a claim invokes 35 U.S.C. .sctn. 112(f),
literally encompassing the recited function and corresponding
structure and equivalents thereto. Its absence does not, unless
there otherwise is insufficient structure recited for that claim
element. Nothing herein or elsewhere restricts the doctrine of
equivalents available to the patentee.
[0076] "Mounted" means physically attached to or held in place by.
This may be by fasteners, adhesives, conduits, brackets, over
molded plastic, or otherwise.
[0077] "Multiple" is generally synonymous with the term "plurality"
and refers to more than one, or by extension, two or more.
[0078] "Planetary Gear" or "Planetary Gearset" generally refers to
a system of at least two gears mounted so that the center of at
least one gear revolves around the center of the other. In other
words, the planetary gear includes a system of epicyclic gears in
which at least one gear axis revolves about the axis of another
gear. In one example, a carrier connects the centers of the two
gears and rotates to carry one gear, which is called a planet gear,
around the other, which is commonly called a sun gear. Typically,
but not always, the planet and sun gears mesh so that their pitch
circles roll without slip. A point on the pitch circle of the
planet gear normally traces an epicycloid curve. In one simplified
case, the sun gear is fixed and the one or more planet gears roll
around the sun gear. In other examples, an epicyclic gear train can
be assembled so the planet gear rolls on the inside of the pitch
circle of a fixed, outer gear ring, or ring gear, that is sometimes
called an annular gear. In this case, the curve traced by a point
on the pitch circle of the planet gear is a hypocycloid. A
planetary gear is typically used to transfer large torque loads in
a compact form.
[0079] "Positive Clutch" generally refers to a type of clutch that
is designed to transmit torque without slippage such as through a
mechanical interference type connection. Some examples of positive
clutches include jaw clutches (e.g., square or spiral jaw clutches)
and dog clutches.
[0080] "Powertrain" generally refers to devices and/or systems used
to transform stored energy into kinetic energy for propulsion
purposes. The powertrain can include multiple power sources and can
be used in non-wheel-based vehicles. By way of non-limiting
examples, the stored energy sources can include chemical, solar,
nuclear, electrical, electrochemical, kinetic, and/or other
potential energy sources. For example, the powertrain in a motor
vehicle includes the devices that generate power and deliver the
power to the road surface, water, and/or air. These devices in the
powertrain include engines, motors, transmissions, drive shafts,
differentials, and/or final drive components (e.g., drive wheels,
continuous tracks, propeller, thrusters, etc.).
[0081] "Predominately" is synonymous with greater than 50%.
[0082] "Rated Continuous Power" or "Continuous Rated Power"
generally refer to an amount of energy or work provided per unit of
time (i.e., power) an electric motor will produce without
interruption for a rated speed, at a rated torque, and at a rated
voltage for the electric motor. In other words, the rated
continuous power is usually the power that the electric motor can
produce for a long period of time at the rated speed and the rated
torque without damaging the electric motor.
[0083] "Rated Operating Speed" or "Rated Speed" generally refers to
a velocity (i.e., speed) an electric motor will rotate when
producing a rated continuous power at a supplied rated voltage for
the electric motor. Typically, but not always, the rated operating
speed is measured in terms of Revolutions Per Minute (rpm).
Generally speaking, the rated operating speed is the prescribed rpm
at which the motor operates, keeping the mechanical stability and
efficiency of the electric motor in mind. The rated voltage and
rated horsepower respectively refer to the maximum voltage and
horsepower (hp) where the motor can operate efficiently without
being damaged. The value for the rated operating speed will be
slightly less than a synchronous speed of the electric motor due to
a decrease in speed caused by adding a load (i.e., slip or speed
loss). For instance, most alternating current (AC) induction motors
with synchronous speeds of 1800 RPM will have normally have rated
speeds ranging between about 1720 and about 1770 RPM depending on
the amount of slip. Some newer high or energy-efficient electric
motors will tend to have rated operating speeds towards a higher
end of the range.
[0084] "Rated Continuous Torque" or "Continuous Rated Torque"
generally refer to a magnitude of twisting force, or torque, an
electric motor will produce without interruption for a rated speed
and at a rated voltage for the electric motor. In other words, the
rated continuous torque is usually a torque that the electric motor
can output for a long period of time at the rated speed without
damaging the electric motor. Typically, this value is generated
close to the maximum speed of the motor.
[0085] "Selectable One-Way Clutch" (SOWC) generally refers to a
type of clutch that is able to be controlled to lock in at least
one rotational direction. One-way clutches are usually (but not
always) designed to transfer torque or lock when rotated in one
direction and to allow rotational movement or free-wheel when
rotated in the opposite direction. The SOWC is a type of one-way
clutch that can be used to control when and/or in which direction
the rotational motion is locked or able to rotate freely. By way of
a non-limiting example, the SOWC can be activated to lock so as to
transfer torque when torque is applied in one rotational direction
and facilitate free-wheel or slipping movement in the opposite
rotational direction. In other variations, the SOWC can be
controlled at times to facilitate free-wheel motion in both
rotational directions or locked to allow torque transfer in both
rotational directions. Alternatively or additionally, the SOWC can
be controlled to switch or change the locked and freewheel
rotational directions. For example, the SOWC under one operating
condition can be locked when rotated in a counterclockwise and
free-wheel spin in the clockwise direction, and under other
conditions, the SOWC can be switched so that the SOWC is locked in
the clockwise direction and freewheel spin in the counterclockwise
direction. Some non-limiting examples of SOWC designs include
roller, sprag, spiral, and mechanical diode type designs. The SOWC
can be controlled or actuated in a number of ways such as through
mechanical and/or electrical actuation. For instance, the SOWC can
be actuated with hydraulic, pneumatic, and/or electrical type
actuators to name just a few.
[0086] "Substantially" generally refers to the degree by which a
quantitative representation may vary from a stated reference
without resulting in an essential change of the basic function of
the subject matter at issue. The term "substantially" is utilized
herein to represent the inherent degree of uncertainty that may be
attributed to any quantitative comparison, value, measurement,
and/or other representation.
[0087] "Symmetric" or "Symmetrical" generally refer to a property
of something having two sides or halves that are the same relative
to one another, such as in shape, size, and/or style. In other
words, symmetric describes something as having a mirror-image
quality.
[0088] "Synchronizer" or "Synchronizer Mechanism" ("Synchromesh")
generally refer to a device that includes a cone clutch and a
blocking ring which brings the speeds of a gear and a gear selector
to the same speed using friction. In one example, before the teeth
of the gear and gear selector can engage, the cone clutch engages
first which in turn brings the gear selector and gear to the same
speed using friction. Until synchronization occurs, the teeth of
the gear and the gear selector are prevented from making contact by
the blocking ring. When synchronization occurs, the friction on the
blocking ring is relieved and the blocking ring twists slightly.
With this twisting motion, grooves or notches are aligned that
allow further passage of the gear selector which brings the teeth
together.
[0089] "Transmission" generally refers to a power system that
provides controlled application of mechanical power. The
transmission uses gears and/or gear trains to provide speed,
direction, and/or torque conversions from a rotating power source
to another device.
[0090] "Upstream" generally refers to a direction or relative
location that is opposite from where power flows in a system.
[0091] "Vehicle" generally refers to a machine that transports
people and/or cargo. Common vehicle types can include land based
vehicles, amphibious vehicles, watercraft, aircraft, and space
craft. By way of non-limiting examples, land based vehicles can
include wagons, carts, scooters, bicycles, motorcycles,
automobiles, buses, trucks, semi-trailers, trains, trolleys, and
trams. Amphibious vehicles can for example include hovercraft and
duck boats, and watercraft can include ships, boats, and
submarines, to name just a few examples. Common forms of aircraft
include airplanes, helicopters, autogiros, and balloons, and
spacecraft for instance can include rockets and rocket-powered
aircraft. The vehicle can have numerous types of power sources. For
instance, the vehicle can be powered via human propulsion,
electrically powered, powered via chemical combustion, nuclear
powered, and/or solar powered. The direction, velocity, and
operation of the vehicle can be human controlled, autonomously
controlled, and/or semi-autonomously controlled. Examples of
autonomously or semi-autonomously controlled vehicles include
Automated Guided Vehicles (AGVs) and drones.
[0092] The term "or" is inclusive, meaning "and/or".
[0093] It should be noted that the singular forms "a," "an," "the,"
and the like as used in the description and/or the claims include
the plural forms unless expressly discussed otherwise. For example,
if the specification and/or claims refer to "a device" or "the
device", it includes one or more of such devices.
[0094] It should be noted that directional terms, such as "up,"
"down," "top," "bottom," "lateral," "longitudinal," "radial,"
"circumferential," "horizontal," "vertical," etc., are used herein
solely for the convenience of the reader in order to aid in the
reader's understanding of the illustrated embodiments, and it is
not the intent that the use of these directional terms in any
manner limit the described, illustrated, and/or claimed features to
a specific direction and/or orientation.
[0095] While the invention has been illustrated and described in
detail in the drawings and foregoing description, the same is to be
considered as illustrative and not restrictive in character, it
being understood that only the preferred embodiment has been shown
and described and that all changes, equivalents, and modifications
that come within the spirit of the inventions defined by the
following claims are desired to be protected. All publications,
patents, and patent applications cited in this specification are
herein incorporated by reference as if each individual publication,
patent, or patent application were specifically and individually
indicated to be incorporated by reference and set forth in its
entirety herein.
TABLE-US-00001 Reference Numbers 100 vehicle 105 powertrain system
110 controller 115 ESS 120 CAN 125 drive shaft 130 propulsion
system 135 wheels 140 power cables 200 electric powertrain 205
transmission 210 first electric motor 212 first inverter 215 second
electric motor 217 second inverter 220 first gear train 225 first
planetary gear 230 sun gear 235 planet gears 240 ring gear 245
first carrier 250 first output shaft 255 SOWC 260 clutch engagement
member 265 clutch actuator 270 second gear train 275 second
planetary gear 277 second output shaft 280 second carrier 285
clutch 290 dog clutch 292 clutch actuator 295 clutch engagement
member 297 first range member 299 second range member 300 electric
powertrain 302 transmission 305 first electric motor 306 first
inverter 307 second electric motor 308 second inverter 309 first
gear train 310 second gear train 315 second planetary gear 320
second carrier 325 first output shaft 330 second output shaft 335
third output shaft 340 first clutch 345 dog clutch 350 clutch
collar 355 clutch actuator 360 clutch engagement member 365 range
member 370 second clutch 375 SOWC 380 clutch engagement member 385
clutch actuator 390 sun gear 392 planet gears 395 ring gear 397
first planetary gear 399 first carrier 505 transmission 510 third
gear train 515 first output shaft 520 second output shaft 525
second clutch 527 second clutch actuator 530 third planetary gear
535 fourth planetary gear 540 third carrier 545 clutch engagement
member 550 second range member 555 first range member
* * * * *