Title of Invention

PARALLEL HYBRID TRANSMISSION HAVING A SINGLE MOTOR/GENERATOR

Abstract This invention relates to a hybrid electro-mechanical transmission (10) comprising ; an input member (17) for receiving power from a power source (12); an output member (19) for delivering power from the transmission (10); a single motor/generator (80); an energy storage device (84) for interchanging electrical power with said motor/generator (80); three planetary gear sets (20,30,40) utilizing first, second and third members (24, 29,22; 39,34,32; 49,42,44); wherein said first, second and third planetary gear sets (20,30,40) are coaxially aligned; wherein said motor/generator (80) annularly circumscribes at least one of said planetary gear sets (20,30,40); first, second and third interconnecting members (70,72,74) each continuously interconnecting a different one of said members of one of said planetary gear sets (20,30,40) to another different one of said members of another of said planetary gear sets (20,30,40); and four torque-transmitting mechanisms (60,62,64,66) operative to connect said members of said gear sets (20,30,40) with other members or with a stationary member (78) and selectively engagable alone or in pairs to provide a reverse mode powered only by said motor/generator (80), a launch mode powered only by said motor/generator (80), and at least five fixed forward speed ratios powered by said power source (12) and with selective assisting power by said motor/generator (80).
Full Text The present invention relates to electrically variable transmissions having
parallel power flow and a single electric unit.
BACKGROUND OF THE INVENTION
Internal combustion engines, particularly those of the reciprocating
piston type, currently propel most vehicles. Such engines are relatively efficient,
compact, lightweight, and inexpensive mechanisms by which to convert highly
concentrated energy in the form of fuel into useful mechanical power. A novel
transmission system, which can be used with internal combustion engines and which can
reduce fuel consumption and emissions, may be of great benefit to the public.
The wide variation in the demands that vehicles typically place on internal
combustion engines increases fuel consumption and emissions beyond the ideal case for
such engines. Typically, a vehicle is propelled by such an engine, which is started from a
cold state by a small electric motor and relatively small electric storage batteries, then
quickly placed under the loads from propulsion and accessory equipment. Such an engine
is also operated through a wide range of speeds and a wide range of loads and typically at
an average of approximately a fifth of its maximum power output.
A vehicle transmission typically delivers mechanical power from an
engine to the remainder of a drive system, such as fixed final drive gearing, axles and
wheels. A typical mechanical transmission allows some freedom in engine operation,
usually through alternate selection of five or six different drive ratios, a neutral selection
that allows the engine to operate accessories with the vehicle stationary, and clutches or a
torque converter for smooth transitions between driving ratios and to start the vehicle
from rest with the engine turning. Transmission gear selection typically allows power
from the engine to be delivered to the rest of the drive system with a ratio of torque


multiplication and speed reduction, with a ratio of torque reduction and speed
multiplication known as overdrive, or with a reverse ratio.
An electric generator can transform mechanical power from the engine
into electrical power, and an electric motor can transform that electric power back into
mechanical power at different torques and speeds for the remainder of the vehicle drive
system. This arrangement allows a continuous variation in the ratio of torque and speed
between engine and the remainder of the drive system, within the limits of the electric
machinery. An electric storage battery used as a source of power for propulsion may be
added to this arrangement, forming a series hybrid electric drive system.
The series hybrid system allows the engine to operate with some
independence from the torque, speed and -power required to propel a vehicle, so the
engine may be controlled for improved emissions and efficiency. This system allows the
electric machine attached to the engine to act as a motor to start the engine. This system
also allows the electric machine attached to the remainder of the drive train to act as a
generator, recovering energy from slowing the vehicle into the battery by regenerative
braking. A series electric drive suffers from the weight and cost of sufficient electric
machinery to transform all of the engine power from mechanical to electrical in the
generator and from electrical to mechanical in the drive motor, and from the useful
energy lost in these conversions.
A power-split transmission can use what is commonly understood to be
"differential gearing" to achieve a continuously variable torque and speed ratio between
input and output. An electrically variable transmission can use differential gearing to
send a fraction of its transmitted power through a pair of electric motor/generators. The
remainder of its power flows through another, parallel path that is all mechanical and
direct, of fixed ratio, or alternatively selectable.
One form of differential gearing, as is well known to those skilled in this
art, may constitute a planetary gear set. Planetary gearing is usually the preferred
embodiment employed in differentially geared inventions, with the advantages of
compactness and different torque and speed ratios among all members of the planetary



gear set. However, it is possible to construct this invention without planetary
gears, as by using bevel gears or other gears in an arrangement where the
rotational speed of at least one element of a gear set is always a weighted
average of speeds of two other elements.
A hybrid electric vehicle transmission system also includes one or more electric
energy storage devices. The typical device is a chemical electric storage battery,
but capacitive or mechanical devices, such as an electrically driven flywheel, may
also be included. Electric energy storage allows the mechanical output power
from the transmission system to the vehicle to vary from the mechanical input
power from the engine to the transmission system. The battery or other device
also allows for engine starting with the transmission system and for regenerative
vehicle braking.
An electrically variable transmission in a vehicle can simply transmit mechanical
power from an engine input to a final drive output. To do so, the electric power
produced by one motor/generator balances the electrical losses and the electric
power consumed by the other motor/generator. By using the above - referenced
electrical storage battery, the electric power generated by one motor/generator
can be greater than or less the electric power consumed by the other. Electric
power from the battery can sometimes allow both motor/generators to act as
motors, especially to assist the engine with vehicle acceleration. Both motors can
sometimes act as generators to recharge the battery, especially in regenerative
vehicle braking.

SUMMARY OF INVENTION
A reduced cost, compact parallel hyboid transmission having only a single
motor/generator is provided. The transmission utilizes a reduced number of
components, preferably only three interconnecting members and four torque-
transmitting mechanisms, to provide a reverse speed mode and seven forward
speed modes. As used herein, a 'mode' is a particular operating state, whether
encompassing a continuous range of speed ratios or only a fixed speed ratio,
achieved by engagement of a particular torque-transmitting mechanism or
torque-transmitting mechanisms. At least five of the forward modes are fixed
speed ratios.
Accordingly there is provided a hybrid electro-mechanical transmission
comprising an input member for receiving power from a power source; an output
member for delivering power from the transmission; a single motor/generator;
an energy storage device for interchanging electrical power with said
motor/generator; three planetary gear sets utilizing first, second and third
members; wherein said first, second and third planetary gear sets are coaxially
aligned; wherein said motor/generator annularly circumscribes at least one of
said planetary gear sets; first, second and third interconnecting members each
continuously interconnecting a different one of said members of one of said
planetary gear sets to another different one of said members of another of said
planetary gear sets; and four torque-transmitting mechanisms operative to
connect said members of said gear sets with other members or with a stationary
member and selectively engagable alone or in pairs to provide a reverse mode
powered only by said motor/generator, a launch mode powered only by said
motor/generator, and at least five fixed forward speed ratios powered by said
power source and with selective assisting power by said motor/generator.


The hybrid electro-mechanical transmission includes an input member for
receiving power from a power source and an output member for delivering power from
the transmission. Only a single motor/generator is used. An energy storage device is
used for interchanging electrical power with the motor/generator. Three planetary gear
sets are utilized each having a first, second and third member. Preferably, the first,
second and third planetary gear sets are coaxially aligned and the motor/generator
annularly circumscribes at least one of the planetary gear sets. First, second and third
interconnecting members each continuously interconnect a different one of the members
of one of the planetary gear sets with another different one of the members of another of
the planetary gear sets. Four torque-transmitting mechanisms are selectively engagable
alone or in pairs to provide a reverse mode powered only by the motor/generator, a
launch mode powered only by the motor/generator and at least five modes of fixed
forward speed ratios powered by the power source and optionally the motor/generator.
That is, the four torque-transmitting mechanisms are operable to provide at least five
fixed forward speed ratios whether or not power flows through the motor/generator.
In one aspect of the invention, the first member of the first planetary gear
set is continuously interconnected with the input member. The first member of the third
planetary gear set is continuously connected with the output member. The first
interconnecting member continuously connects the second member of the first planetary
gear set with the first member of the second planetary gear set. The second
interconnecting member continuously connects the third member of the first planetary
gear set with the second member of the second planetary gear set. The third
interconnecting member continuously connects the third member of the second planetary
gear set with the second member of the third planetary gear set. Preferably, the
interconnecting members are concentric.



In another aspect of the invention, a control unit is provided for regulating
electrical power interchange between the energy storage device and the motor/generator.
In another aspect of the invention, the first, second and third members of
each of the planetary gear sets include a ring gear member, a sun gear member and a
carrier member. The ring gear member of the first planetary gear set is continuously
connected with the input member and the carrier member of the third planetary gear set is
continuously connected with the output member. The carrier member of the first
planetary gear set is continuously connected with the carrier member of the second
planetary gear set via the first interconnecting member. The sun gear member of the first
planetary gear set is continuously connected with the ring gear member of the second
planetary gear set via the second interconnecting member. The sun gear member of the
third planetary gear set is continuously connected with the motor/generator and is
continuously connected to the sun gear member of the second planetary gear set via the
third interconnecting member.
In still another aspect of the invention, the first torque-transmitting
mechanism selectively connects the ring gear member of the first planetary gear set with
the ring gear member of the second planetary gear set. The second torque-transmitting
mechanism selectively connects the sun gear member of the first planetary gear set with
the stationary member. The third torque-transmitting mechanism selectively connects the
ring gear member of the third planetary gear set with the stationary member. The fourth
torque-transmitting mechanism selectively connects the carrier members of the first and
second planetary gear sets with the carrier member of the third planetary gear set.
This single motor/generator parallel hybrid transmission has a lower
overall transmission cost because a second motor/generator is not used nor is a second
power inverter necessary, as is typically required for an additional motor/generator.
Additionally, at cruise during the seventh forward speed mode, no power (i.e.,
substantially zero) flows through the motor/generator yet the motor/generator provides
significant torque at a very low speed.


The above features and advantages and other features and advantages of
the present invention are readily apparent from the following detailed description of the
best modes for carrying out the invention when taken in connection with the
accompanying drawings.
BRIEF DESCRIPTION OF THE ACCOMPANYING DWINGS
FIGURE 1A is a schematic representation of an electro-mechanical
transmission having a single motor/generator embodying the concepts of the present
invention;
FIGURE 1B is a chart depicting various operating conditions of the
electro-mechanical transmission of Figure 1A;
FIGURE 2 is a graphical representation of the speed in rotations per
minute (rpm) of the motor/generator as well as the engine and the output member relative
to the speed of the vehicle in miles per hour (mph) during transient pull conditions;
FIGURE 3 is a graphical representation of horsepower (hp) of the
motor/generator, the engine, the energy storage device and the output member relative to
the speed of the vehicle in miles per hour (mph) during transient pull conditions;
FIGURE 4 is a graphical representation of the speed in rotations per
minute (rpm) of the motor/generator, the engine and the output member relative to the
speed of the vehicle in miles per hour (mph) during cruise conditions; and
FIGURE 5 is a graphical representation of horsepower (hp) of the
motor/generator, the engine and the output member relative to the speed of the vehicle in
miles per hour (mph) during cruise conditions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
One representative form of an electro-mechanical transmission having a
single motor/generator embodying the concepts of the present invention is depicted in
Figure 1A, and is designated generally by the numeral 10. The hybrid transmission 10
has an input member 17 that may be in the nature of a shaft which may be directly driven



by an engine 12. The engine 12 may be a fossil fuel engine, such as an internal
combustion engine or a diesel engine, which is readily adapted to provide its available
power output delivered at a constant number of revolutions per minute (rpm). A pump 18
may be driven off of the input member 17 for providing lubrication and cooling fluid
throughout the transmission 10. Power flows from the input member 17 through the
transmission 10 as will be described below to be delivered at an output member 19 for
powering a final drive 16.
The transmission 10 includes a first planetary gear set 20 that includes a
sun gear member 22, a ring gear member 24 circumscribing the sun gear member 22 and
a planet carrier assembly member 26 including a plurality of pinion gear 27 rotatably
mounted on a carrier member 29 in meshingly engaging with both the ring gear member
,24 and the sun gear member 22. The input member 17 is continuously connected with
the ring gear member 24 for providing power thereto.
The transmission 10 further includes a second planetary gear set 30
including a sun gear member 32, a ring gear member 34 circumscribing the sun gear
member 32 and a planet carrier assembly member 36 including a plurality of pinion gears
37 rotatably supported on a carrier member 39 and meshing engaging both the ring gear
member 34 and the sun gear member 32. The carrier member 29 is continuously
connected with the carrier member 39 via an interconnecting member 70 which is an
interconnecting shaft. The sun gear member 22 is continuously connected with the ring
gear member 34 via an interconnecting member 72, which is a rotatable sleeve shaft and
is concentrically arranged about interconnecting member 70.
[0028] Furthermore, the transmission 10 includes a third planetary gear set 40
including a sun gear member 42, a ring gear member 44 circumscribing the sun gear
member 42 and a planet carrier assembly member 46 including a plurality of pinion gears
47 rotatably mounted on a carrier member 49 and meshingly engaging with both the ring
gear member 44 and the sun gear member 42. The sun gear member 32 is continuously
connected with the sun gear member 42 via an interconnecting member 74 which is



another rotatable sleeve shaft concentrically arranged about interconnecting member 70.
The carrier member 49 is continuously connected with the output member 19.
The input member 17 and output member 19 are aligned to form an axis of
rotation therethrough. A single motor/generator 80 (which maybe referred to herein as an
electric unit) is concentrically disposed about the common axis of rotation formed by the
input member 17 and output member 19 for rotation thereabout. As will be well
understood by those skilled in the art, the motor/generator 80 includes a stator secured to
a stationary member such as a transmission housing 78 as well as a rotatable rotor. The
rotor of the motor/generator 80 is secured to the sun gear members 32 and 42 for
common rotation therewith via a hub 76 and interconnecting member 74.
As should be apparent from the foregoing description, the transmission 10
selectively receives power from the engine 12. The hybrid transmission may also receive
power from an energy storage device 84 such as a battery pack. Other electric storage
devices that have the ability to store electric power and dispense electric power may be
used in place of the battery pack without altering the concepts of the present invention.
The battery pack 84 may include one or more batteries. The power output of the battery
pack 84 is not critical to the invention, but for the purpose of affecting a clear
understanding of the hybrid transmission 10} an output power of about 35 horsepower
(hp) from the battery pack 84 will be assumed for description of the transmission 10. The
battery pack 84 will be sized depending on regenerative requirements, regional issues
such as grade and temperature, and other requirements such as emissions, power assist
and electric range.
The battery pack 84 communicates with an electrical control unit (ECU)
82 by transfer conductors 88A and 88B. The ECU 82 communicates with the
motor/generator 80 by transfer conductors 88C and 88D. Additionally, the ECU 82
communicates with other vehicle electrical components 86, such as electrical power
steering, and electrical power braking systems, etc., via transfer conductors 88E and 88F.
Preferably, the maximum electrical power requirements of the other electrical



components 86 is such that no more than 2 horsepower (hp) is required to power these
components.
The ECU 82 responds to a variety of input signals including vehicle speed,
operator demand, the level to which the battery pack 84 is charged and the power being
applied by the engine 12, to regulate the flow of power between the motor/generator 80
and the battery pack 84. The ECU 82 can manipulate the motor/generator 80 to act as
either a motor or a generator. The ECU 82 also regulates the flow of power via transfer
conductors 88G and 88H between the battery pack 84 and the motor/generator 80 through
power inverter 89 to convert between direct current power utilized by the battery pack 84
and alternating current power utilized by and/or generated by the motor/generator 80.
A first torque-transmitting mechanism 60, which is a rotating clutch
torque-transmitting mechanism, selectively connects the ring gear member 24 with the
sun gear member 22 and also with the ring gear member 34 via the interconnecting
member 72. Thus, when the torque-transmitting mechanism 60:is engaged, the ring gear
member 24 and the sun gear member 22 rotate at the same speed, causing the entire
planetary gear set 20 to rotate at the speed of the input member 17. A second torque-
transmitting mechanism 62, which is a brake, selectively engages the sun gear member
22 and the ring gear member 34 with the stationary transmission housing 78. A third
torque-transmitting mechanism 64, which is also a brake, selectively engages the ring
gear member 44 with the transmission housing 78. Finally, a fourth torque-transmitting
mechanism 66, which is a rotating type clutch, selectively engages the carrier members
29 and 39 with the carrier member 49 and also the output member 19 via interconnecting
member 70. The engagement schedule of the torque-transmitting mechanisms 60, 62, 64
and 66 is provided in Figure 1B. As maybe seen from the truth table of Figure 1B, a
reverse battery powered mode, a first battery powered forward mode, as well as second,
third, fourth, fifth, sixth and seventh forward speed ratio modes are provided by the
transmission 10. The speed ratios shown in Figure 1B are for purposes of example only
and are achieved with tooth ratio counts as follows. In the planetary gear set 20, the ring
gear member 24 has 91 teeth and the sun gear member 22 has 35 teeth; in the planetary


gear set 30 the ring gear member 34 has 91 teeth and the sun gear member 32 has 45
teeth; and in the planetary gear set 40, the ring gear member 44 has 91 teeth and the sun
gear member 42 has 23 teeth.
Reverse Mode
To establish a reverse mode with a reverse direction of drive, the torque-
transmitting mechanism 64 is engaged to connect the ring gear member 44 with the
transmission housing 78. The engine 12 may not be utilized in the reverse mode because
the rotation of the input member 17 is necessarily in the same direction of rotation as the
output member 19 in the transmission 10. Accordingly, the motor/generator 80 acts as a
motor to power the output member 19 in a reverse direction when clutch 64 is engaged
and the electronic control unit 82 determines that reverse is required by operator demand.
Electronic control unit 82 signals the battery pack 84 to power the motor/generator 80 via
electrical power routed through the inverter 89 along transfer conductors 88G and 88H.
Accordingly, assuming that a clockwise direction of rotation of the output member 19 is
able to power the vehicle in a forward direction, the motor/generator is powered to act as
a motor by rotating in counterclockwise direction, therefore turning the sun gear member
42 in counterclockwise direction. Because the ring gear member 44 is held stationary by
the brake 64, the pinion gears 47 rotate in a clockwise direction and the carrier member
49, and therefore the output member 19 rotates in a counterclockwise direction.
Referring to Figure 2, operating speeds during sample transient pull
conditions are illustrated (i.e., conditions in which the vehicle is subjected to heavy
loading or acceleration). The reverse operation is illustrated in the portion of the graph
with negative vehicle speeds. The speed of the engine is illustrated by the plot 90, the
speed of the electric unit is illustrated by the plot 92, and the speed of the transmission
output member is illustrated by the plot 94. When the vehicle speed is negative, the
electric unit and transmission output member both rotate in the same direction. The
speed of the engine is shown at plot 90; however, power is not added by the engine 12
during the reverse operating mode.


Figure 3 illustrates the power of various components during the transient
pull conditions that result in the speeds of Figure 2. Horsepower of the engine is denoted
by plot 100, horsepower of the electrical unit 80 is denoted by plot 102, horsepower of
the battery pack 84 is denoted by plot 104 and horsepower at the transmission output
member 19 is denoted by plot 106. When the vehicle has a negative speed, the power at
the output member 19 is the same as the power of the motor/generator 80, and therefore
the plots 102 and 106 overlay one another in the reverse operating mode (i.e., when
vehicle speeds are negative). Power through the engine 12, shown at plot 100, is zero in
this range. Additionally, power through the battery is at its maximum level, 35
horsepower (hp).
Launch/First Forward Mode
When the transmission 10 is used to launch the vehicle, the torque-
transmitting mechanism 64 is engaged just as it was in the reverse mode. The
motor/generator 80 is the prime mover in the first/launch mode, acting as a motor via
power received from the battery pack 84 under the control of the electronic control unit
82. The rotor portion of the motor/generator is controlled to rotate in a clockwise
direction, thereby rotating the interconnecting member 74 and the sun gear member 42 in
a clockwise direction. Because the ring gear member 44 is braked, with the sample tooth
count discussed above, the carrier member 49 and output member 19 will be driven in a
clockwise or forward direction of rotation for powering the final drive 16. The engine 12
may be utilized to add power during launch if the torque-transmitting mechanism 60 is
engaged at a slip (i.e. less than full engagement) such that the entire planetary gear set 20
rotates in the same direction as the input member 17 to thereby add driving power to the
ring gear member 34.
The operating characteristics of transmission components such as the
engine 12, the motor/generator 80 and the output member 19 in the first forward mode
are depicted in Figures 2 and 3 between the Y-axis and the vertical line A for transient
pull conditions. Operating speeds of various components during continuous cruise
conditions are illustrated at Figures 4 and 5. The speed of the engine 12 is illustrated by


plot 190, the speed of the electric unit 80 is illustrated by plot 192 and the speed of the
transmission output member 19 is illustrated by plot 194. Figure 5 illustrates the power
of various components during the continuous cruise conditions that result in the speeds of
Figure 4. Horsepower of the engine 12 is denoted by plot 200, horsepower of the
electrical unit 80 is denoted by plot 202, and horsepower at the transmission output
member 19 is denoted by plot 206. Operating characteristics in the first forward mode
during cruising conditions are between the Y-axis and vertical line A' in both Figures 4
and 5. In transient pull conditions, for all forward vehicle speeds, the motor/generator 80
operates as a motor to add torque and power to the transmission 10 while in the
continuous cruise condition of Figures 4 and 5, the motor/generator 80 operates as a
generator to power the battery pack 84, or other vehicle electrical components 86.
Second Forward Mode
The second forward mode indicated in Figure 1B is established with the
engagement of the torque-transmitting mechanisms 60 and 64 and establishes a first fixed
forward speed ratio. A "fixed speed ratio" is an operating condition in which the power
input to the transmission is transmitted mechanically to the output member, and no power
flow is necessary in the motor/generators. An electrically variable transmission that may
selectively achieve fixed speed ratios for operation near full engine power can be smaller
and lighter for a given maximum capacity. Fixed ratio operation may also result in lower
fuel consumption when operating under conditions where the engine speed can approach
its optimum without using the motor/generators. A variety of fixed speed ratios and
variable ratio spreads can be realized by suitably selecting the tooth ratios of the
planetary gear sets or gear members in a transmission.
The torque-transmitting mechanism 60 connects the input member 17 and
ring gear member 24 with the sun gear member 22 and the torque-transmitting
mechanism 64 connects the ring gear member 44 with the transmission housing 78. The
planetary gear sets 20 and 30 as well as the sun gear member 42 rotate at the same speed
as the input member 17. The ring gear member 44 does not rotate. The carrier member
49 rotates at the same speed as the output member 19. The carrier member 49, and


therefore the output member 19, rotates at a speed determined from the speed of the sun
gear member 42 and the ring gear/sun gear tooth ratio of the planetary gear set 40. The
operating characteristics of the transmission components in the second forward mode/first
fixed speed ratio are depicted at Figures 2 and 3 between the vertical lines A and B for
transient pull conditions and at Figures 4 and 5 between vertical lines A' and B' (for
cruising conditions).
Third Forward Mode
A third forward mode is established with the engagement of the torque-
transmitting mechanisms 62 and 64 and results in a second fixed forward speed ratio as
indicated in Figure 1B. The torque-transmitting mechanism 62 grounds the sun gear
member 22 to the transmission housing 78 and the torque-transmitting mechanism 64
grounds the ring gear member 44 to the transmission housing 78. The ring gear member
24 rotates at the same speed as the input member 17. The carrier members 29 and 39
rotate at the same speed. The sun gear member 22, the ring gear member 34 and the ring
gear member 44 do not rotate. The carrier member 29 rotates at a speed determined from
the speed of the ring gear member 24 and the ring gear/sun gear tooth ratio of the
planetary gear set 20. The sun gear member 32 rotates at the same speed as the sun gear
member 42. The sun gear member 32 rotates at a speed determined from the speed of the
carrier member 39, and the ring gear/sun gear tooth ratio of the planetary gear set 30.
The carrier member 49 rotates at the same speed as the output member 19. The carrier
member 49, and therefore the output member 19, rotates at a speed determined from the
speed of the sun gear member 42, and the ring gear/sun gear tooth ratio of the planetary
gear set 40. The operating characteristics of transmission components in the third
forward mode are depicted at Figures 2 and 3 between vertical lines B and C for transient
pull conditions and at Figures 4 and 5 between vertical lines B' and C (for cruising
conditions).


Fourth Forward Mode
A fourth forward mode is established with the engagement of the torque-
transmitting mechanisms 64 and 66 and results in a third fixed forward speed ratio, as
indicated in Figure 1B. The torque-transmitting mechanism 64 grounds the ring gear
member 44 to the transmission housing 78 and the torque-transmitting mechanism 66
connects the carrier members 39 and 49 with one another. The ring gear member 24
rotates at the same speed as the input member 17. The carrier members 29, 39 and 49
rotate at the same speed as the output member 19. The sun gear member 22 rotates at the
same speed as the ring gear member 44. The carrier member 29, and therefore the output
member 19, rotates at a speed determined from the speed of the sun gear member 22, the
speed of the ring gear member 24 and the ring gear/sun gear tooth ratio of the planetary
gear set 20., The operating characteristics of the transmission components in the fourth
forward mode are depicted in Figures 2 and 3 between vertical lines C and D (for
transient pull conditions) and at Figures 4 and 5 between vertical lines C and D' (for
cruising conditions).
Fifth Forward Mode
A fifth forward mode is established with the engagement of the torque-
transmitting mechanisms 62 and 66 and establishes a fourth fixed forward speed ratio.
The torque-transmitting mechanism 62 connects the sun gear member 22 with the
transmission housing 78 and the torque-transmitting mechanism 66 connects the carrier
member 39 with the carrier member 49. The ring gear member 24 rotates at the same
speed as the input member 17. The carrier members 29, 39 and 49 rotate at the same
speed as the output member 19. The sun gear member 22 does not rotate. The carrier
member 29, and therefore the output member 19, rotates at a speed determined from the
speed of the ring gear member 24 and the ring gear/sun gear tooth ratio of the planetary
gear set 20. Operating characteristics of transmission components in the fifth forward
mode are depicted at Figures 2 and 3 between vertical lines D and E (for transient pull
conditions) and at Figures 4 and 5 between vertical lines D' and E' (for cruising
conditions).


Sixth Forward Mode
A sixth forward mode is established with the engagement of the torque-
transmitting mechanisms 60 and 66 and results in a direct drive ratio of 1.0 with the input
member 17 and output member rotating 19 at the same speed, as indicated in Figure IB.
This direct drive ratio is established with the engagement of the torque-transmitting
mechanisms 60 and 66. The torque-transmitting mechanism 60 connects the ring gear
member 24 with the sun gear member 22 and the torque-transmitting mechanism 66
connects the carrier members 39 and 49 with one another. Each of the planetary gear sets
20, 30 and 40 rotate at the same speed as the input member 17. Operating characteristics
of the transmission components in the sixth forward mode are depicted in Figures 2 and 3
between vertical lines E and F (for transient pull conditions) and at Figures 4 and 5
between vertical lines E' and F' (for cruising conditions).
Seventh Forward Mode
A seventh forward mode is established with the engagement of the torque-
transmitting mechanism 66. The ring gear member 24 rotates at the same speed as the
input member 17. The carrier members 29, 39 and 49 are interconnected to rotate at the
same speed as the output member 19. The sun gear member 22 rotates at the same speed
as the ring gear member 24. The carrier member 29, and therefore the output member 19,
rotates at a speed determined from the speed of the sun gear member 22 and the ring
gear/sun gear tooth ratio of the planetary gear set 20. Operating characteristics of the
transmission components in the seventh mode are depicted at Figures 2 and 3 to the right
of vertical line F (for transient pull conditions) and at Figures 4 and 5 to the right of
vertical line F' (for cruising conditions). As is apparent from Figures 2 and 3, in the
overdrive seventh range, in order for the motor/generator to operate as a motor, it must
rotate in a direction opposite that of the engine and output member 19. It rotates at a low
speed such that very little power goes through the motor/generator 80, but significant
torque is added. When the motor/generator 80 is controlled to act as a motor in the
seventh forward mode, power flows from the engine 12 and input member 17 through the
ring gear member 24 and the intermeshing pinion gears 27 to the carrier member 29.

Power flows from the carrier member 29 to both carrier members 39 and 49 via
interconnecting member 70. Power flowing to the carrier member 49 is transmitted to the
output member 19. Power flows from the battery pack 84 to cause the motor/generator
80 (and interconnecting member 74) to rotate in an opposite direction as the input
member 17 and output member 19, adding power to the planetary gear set 30 which flows
through the sun gear member 32, the pinion gears 37 and to the ring gear member 34,
where it is added to the power delivered from the planetary gear set 20 to the carrier
member 39. This power then circulates back to the planetary gear set 20 via the
interconnecting member 72, to be added to the power delivered from the input member
17- at the carrier member 29.
During continuous operation, as depicted in Figures 4 and 5, in the seventh
forward mode the motor/generator 80 rotates slowly in the same direction as engine 12
and output member 19 because the motor/generator must operate as the generator. Only
a relatively small amount of electric power goes through the motor/generator and the
speed of the motor/generator is low; however, torque of the motor/generator is high.
When the motor/generator 80 is controlled to act as a generator in the seventh forward
mode, power flows from the engine 12 and input member 17 through the first planetary
gear set 20 to both carrier members 39 and 49 and to the output member 19 in the same
manner as described above. However, power flowing to the carrier member 39 is split by
the planetary gear set 30, with some of the power flowing through the pinion gears 37
and sun gear member 32 to power the motor/generator 80. Power flows to the battery
pack 84 or other electrical components 86 to cause the motor/generator 80 (and
interconnecting member 74) to rotate in the same direction as the input member 17 and
output member 19. The rest of the power flowing to the carrier member 39 circulates
back to the planetary gear set 20 via the pinion gears 37, the ring gear member 34 and the
interconnecting member 72. The power circulated back to the planetary gear set 20 then
flows through the sun gear member 22, the pinion gears 27 and the carrier member 29.


As is evidenced in Figures 3 and 5, power at the transmission output
member 19 is lowest in any given forward mode just after the shift to that mode. This
"droop" in engine power may be supplemented by operating the motor/generator 80 as a
motor to add torque and therefore power during the period of drop in engine power.
Thus, the transmission 10 provides fuel economy and emissions benefits
by utilizing an electrically (battery) powered reverse and first forward mode while still
providing five fixed forward ratios and a seventh, overdrive mode in which the
motor/generator 80 may add power to the transmission 10 or may act as a generator to
recharge theenergy storage device 84 while operating at a very low speed.
While the best modes for carrying out the invention have been described
in detail, those familiar with the art to which this invention relates will recognize various
alternative designs and embodiments for practicing the invention within the scope of the
appended claims.


WE CLAIM
1. A hybrid electro-mechanical transmission (10) comprising:
an input member (17) for receiving power from a power source (12);
an output member (19) for delivering power from the transmission (10);
a single motor/generator (80);
an energy storage device (84) for interchanging electrical power with said
motor/generator (80);
three planetary gear sets (20,30,40) utilizing first, second and third
members (24, 29,22; 39,34,32; 49,42,44);
wherein said first, second and third planetary gear sets (20,30,40) are
coaxially aligned;
wherein said motor/generator (80) annularly circumscribes at least one of
said planetary gear sets (20,30,40);
first, second and third interconnecting members (70,72,74) each
continuously interconnecting a different one of said members of one of
said planetary gear sets (20,30,40) to another different one of said
members of another of said planetary gear sets (20,30,40); and



four torque-transmitting mechanisms (60,62,64,66) operative to connect
said members of said gear sets (20,30,40) with other members or with a
stationary member (78) and selectively engagable alone or in pairs to
provide a reverse mode powered only by said motor/generator (80), a
launch mode powered only by said motor/generator (80), and at least five
fixed forward speed ratios powered by said power source (12) and with
selective assisting power by said motor/generator (80).
2. The electro-mechanical transmission as claimed in claim 1, wherein said
first member (24) of said first planetary gear set (20) is continuously
connected with said input member (17);
wherein said first member (49) of said third planetary gear set (30) is
continuously connected with said output member (19);
wherein said first interconnecting member (70) continuously connects said
second member (29) of said first planetary gear set (20) with said first
member (37) of said second planetary gear set (30);
wherein said second interconnecting member (72) continuously connects
said third member (22) of said first planetary gear set (20) with said
second member (34) of said second planetary gear set (30); and
wherein said third interconnecting member (74) continuously connects
said third member (32) of said second planetary gear set (30) with said
second member (42) of said third planetary gear set (40).


3. The electro-mechanical transmission as claimed in claim 2, wherein said
first torque-transmitting mechanism (60) selectively connects said input
member (17) with said third member (22) of said first planetary gear set
(20) to thereby cause all members (22,24,29) of said first planetary gear
set (20) to rotate at a speed of said input member (17).
4. The electro-mechanical transmission as claimed in claim 2, wherein said
second torque-transmitting mechanism (62) selectively connects said third
member (22) of said first planetary gear set (20) with said stationary
member (78).
5. The electro-mechanical transmission as claimed in claim 2, wherein said
third torque-transmitting mechanism (64) selectively connects said third
member (44) of said third planetary gear set (40) with said stationary
member (78).
6. The electro-mechanical transmission as claimed in claim 2, wherein said
fourth torque-transmitting mechanism (66) selectively connects said
interconnected second member (29) of said first planetary gear set (20)
and first member (39) of said second planetary gear set (30) with said
output member (19).
7. The electro-mechanical transmission as claimed in claim 2, comprising a
control unit (82) for regulating electrical power interchange between said
energy storage device (84) and said motor/generator (80).


8. The electro-mechanical transmission as claimed in claim 1, wherein said
motor/generator (80) annularly circumscribes at least one of said
planetary gear sets (20,30,40).
9. The electro-mechanical transmission as claimed in claim 1, wherein said
interconnecting members (70,72,74) are concentric.
10.The hybrid electro-mechanical transmission as claimed in claim 1, wherein
said first, second and third members of each of said planetary gear sets
include a ring gear member, a sun gear member and a carrier member;
wherein said ring gear member of said first planetary gear set is
continuously connected with said input member;
wherein said carrier member of said third planetary gear set is
continuously connected with said output member;
wherein said carrier member of said first planetary gear set is
continuously connected with said carrier member of said second planetary
gear set via said first interconnecting member;
wherein said sun gear member of said first planetary gear set is
continuously connected with said ring gear member of said second
planetary gear set via said second interconnecting member; and



wherein said sun gear member of said third planetary gear set is
continuously connected with said motor/generator and is continuously
connected to said sun gear member of said second planetary gear set via
said third interconnecting member.
11.The hybrid electro-mechanical transmission as claimed in claim 1 or 10,
wherein said first torque-transmitting mechanism selectively connects said
ring gear member of said first planetary gear set with said sun gear
member of said first planetary gear set.
12.The. hybrid electro-mechanical transmission as claimed in claim 1 or 10,
wherein said second torque-transmitting mechanism selectively connects
said sun gear member of said first planetary gear set with said stationary
member.
13.The hybrid electro-mechanical transmission as claimed in claim 1 or 10,
wherein said third torque-transmitting mechanism selectively connects
said ring gear member of said third planetary gear set with said stationary
member.
14.The hybrid electro-mechanical transmission as claimed in claim 1 or 10,
wherein said fourth torque-transmitting mechanism selectively connects
said carrier member of said second planetary gear set with said carrier
member of said third planetary gear set.


15.The hybrid electro-mechanical transmission as claimed in claim 1, wherein
selective engagement of selected ones of said four torque-transmitting
mechanisms alone or in pairs provides at least five fixed forward speed
ratios whether or not power flows through said motor/generator.


This invention relates to a hybrid electro-mechanical transmission (10)
comprising ; an input member (17) for receiving power from a power source
(12); an output member (19) for delivering power from the transmission (10); a
single motor/generator (80); an energy storage device (84) for interchanging
electrical power with said motor/generator (80); three planetary gear sets
(20,30,40) utilizing first, second and third members (24, 29,22; 39,34,32;
49,42,44); wherein said first, second and third planetary gear sets (20,30,40) are
coaxially aligned; wherein said motor/generator (80) annularly circumscribes at
least one of said planetary gear sets (20,30,40); first, second and third
interconnecting members (70,72,74) each continuously interconnecting a
different one of said members of one of said planetary gear sets (20,30,40) to
another different one of said members of another of said planetary gear sets
(20,30,40); and four torque-transmitting mechanisms (60,62,64,66) operative to
connect said members of said gear sets (20,30,40) with other members or with a
stationary member (78) and selectively engagable alone or in pairs to provide a
reverse mode powered only by said motor/generator (80), a launch mode
powered only by said motor/generator (80), and at least five fixed forward speed
ratios powered by said power source (12) and with selective assisting power by
said motor/generator (80).

Documents:

00890-kol-2006 abstract.pdf

00890-kol-2006 claims.pdf

00890-kol-2006 correspondenceothers.pdf

00890-kol-2006 description(complete).pdf

00890-kol-2006 drawings.pdf

00890-kol-2006 form1.pdf

00890-kol-2006 form2.pdf

00890-kol-2006 form3.pdf

00890-kol-2006 form5.pdf

00890-kol-2006 prioritydocument.pdf

00890-kol-2006-correspondence-1.1.pdf

00890-kol-2006-form-26.pdf

00890-kol-2006-priority document-1.1.pdf

890-KOL-2006-(20-02-2012)-CORRESPONDENCE.pdf

890-kol-2006-abstract-1.1.pdf

890-kol-2006-abstract.pdf

890-kol-2006-amanded claims.pdf

890-kol-2006-assignment 1.1.pdf

890-kol-2006-assignment.pdf

890-kol-2006-cancelled docoment.pdf

890-kol-2006-claims.pdf

890-kol-2006-correspondence 1.1.pdf

890-KOL-2006-CORRESPONDENCE--1.1.pdf

890-KOL-2006-CORRESPONDENCE-1.1.pdf

890-kol-2006-correspondence.pdf

890-kol-2006-description complate.pdf

890-kol-2006-drawings.pdf

890-kol-2006-examination report reply recieved 1.1.pdf

890-kol-2006-examination report.pdf

890-kol-2006-form 1 1.1.pdf

890-kol-2006-form 1.pdf

890-kol-2006-form 18.pdf

890-kol-2006-form 2 1.1.pdf

890-kol-2006-form 2.pdf

890-kol-2006-form 26.pdf

890-kol-2006-form 3.pdf

890-kol-2006-form 5.pdf

890-kol-2006-form 6 1.1.pdf

890-kol-2006-form 6.2.pdf

890-kol-2006-form 6.pdf

890-KOL-2006-FORM-27.pdf

890-kol-2006-gpa.pdf

890-kol-2006-granted-abstract.pdf

890-kol-2006-granted-claims.pdf

890-kol-2006-granted-description (complete).pdf

890-kol-2006-granted-drawings.pdf

890-kol-2006-granted-form 1.pdf

890-kol-2006-granted-form 2.pdf

890-KOL-2006-GRANTED-LETTER PATENT.pdf

890-kol-2006-granted-specification.pdf

890-kol-2006-others 1.1.pdf

890-kol-2006-others.pdf

890-kol-2006-others1.2.pdf

890-kol-2006-pa 1.1.pdf

890-kol-2006-petition under rule 137.pdf

890-KOL-2006-PRIORITY DOCUMENT.pdf

890-kol-2006-reply to examination report.pdf

890-kol-2006-reply to examination report1.1.pdf

890-kol-2006-translated copy of priority document.pdf

abstract-00890-kol-2006.jpg


Patent Number 248187
Indian Patent Application Number 890/KOL/2006
PG Journal Number 26/2011
Publication Date 01-Jul-2011
Grant Date 27-Jun-2011
Date of Filing 01-Sep-2006
Name of Patentee GENERAL MOTORS LLC
Applicant Address 300 RENAISSANCE CENTER, DETROIT, MICHIGAN 48265-3000,USA
Inventors:
# Inventor's Name Inventor's Address
1 MICHAEL R. SCHMIDT 4620 BUCKINGHAM COURT CARMEL, INDIANA 46033
PCT International Classification Number F16H3/72; F16H3/44
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 11/217,923 2005-09-01 U.S.A.