U.S. patent application number 10/629391 was filed with the patent office on 2004-02-05 for electric hybrid vehicle.
This patent application is currently assigned to Field Hybrids, LLC. Invention is credited to Field, Bruce F..
Application Number | 20040020697 10/629391 |
Document ID | / |
Family ID | 27128597 |
Filed Date | 2004-02-05 |
United States Patent
Application |
20040020697 |
Kind Code |
A1 |
Field, Bruce F. |
February 5, 2004 |
Electric hybrid vehicle
Abstract
A hybrid vehicle is provided, which includes an electric motor,
an engine, first and second electrical storage mechanisms, an
energy conversion device and a voltage reducer. The electric motor
and the engine are drivably connectable to propel the vehicle. The
first electrical storage mechanism powers the electric motor. The
energy conversion device is continuously coupled to the engine for
providing a charging power output to the first electrical storage
mechanism whenever the engine is running. The second electrical
storage mechanism provides power to vehicle accessories at a lower
voltage than the first electrical storage mechanism. The voltage
reducer has an input coupled to the generator and the first
electrical storage mechanism and has an output coupled to the
second electrical storage mechanism to provide charging power at
the lower voltage to the second electrical storage mechanism.
Inventors: |
Field, Bruce F.; (Golden
Valley, MN) |
Correspondence
Address: |
David D. Brush
Westman, Champlin & Kelly
Suite 1600
900 Second Avenue South
Minneapolis
MN
55402-3319
US
|
Assignee: |
Field Hybrids, LLC
33 south 6th Street
Minneapolis
MN
55402
|
Family ID: |
27128597 |
Appl. No.: |
10/629391 |
Filed: |
July 29, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10629391 |
Jul 29, 2003 |
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10194745 |
Jul 12, 2002 |
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10194745 |
Jul 12, 2002 |
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09483008 |
Jan 13, 2000 |
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6481516 |
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09483008 |
Jan 13, 2000 |
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08705001 |
Aug 29, 1996 |
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6044922 |
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08705001 |
Aug 29, 1996 |
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07948288 |
Sep 21, 1992 |
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07948288 |
Sep 21, 1992 |
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07880967 |
May 8, 1992 |
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Current U.S.
Class: |
180/65.23 ;
903/951 |
Current CPC
Class: |
B60W 10/08 20130101;
B60L 53/14 20190201; B60W 20/13 20160101; B60L 58/20 20190201; B60W
20/10 20130101; B60K 6/40 20130101; B60L 2240/421 20130101; B60L
2240/441 20130101; Y02T 10/64 20130101; B60L 2260/28 20130101; B60W
10/26 20130101; B60L 50/62 20190201; B60W 2710/081 20130101; B60K
6/442 20130101; B60W 10/06 20130101; Y10S 903/951 20130101; B60L
50/16 20190201; B60W 2510/081 20130101; Y02T 10/62 20130101; Y02T
10/7072 20130101; B60K 2006/268 20130101; Y02T 90/14 20130101; B60L
50/61 20190201; B60W 2510/0638 20130101; B60W 2710/0644 20130101;
Y02T 10/70 20130101; B60W 20/00 20130101 |
Class at
Publication: |
180/65.2 |
International
Class: |
B60K 006/00 |
Claims
What is claimed is:
1. A hybrid vehicle assembly comprising: an electric
motor/generator, which is operable as a motor and as an electrical
energy generator; an engine; a connection between the electric
motor/generator and the engine; a first electrical storage
mechanism connected to the electric motor/generator for selectively
powering the electric motor/generator; an energy conversion device
continuously connected to the engine; a second electrical storage
mechanism; and a voltage reducer coupled to the first electrical
storage mechanism, the energy conversion device and the second
electrical storage mechanism so as to provide charge from the first
electrical storage mechanism, the energy conversion device and the
electrical energy generator to the second electrical storage
mechanism.
2. The hybrid vehicle assembly of claim 1 and further comprising: a
motor controller for rotating and controlling the rotational speed
of the electric motor/generator; a process controller to control
the engine, the process controller controlling the engine to vary a
rotational speed of the engine so as to be substantially
synchronized with the speed of the electric motor/generator; and a
mechanical connection for connecting the engine to drive at least
one ground engaging drive wheel when the engine speed is
substantially synchronized with the electric motor speed.
3. The hybrid vehicle assembly of claim 2, wherein the process
controller is connected to the motor controller to selectively
switch the electric motor/generator to operate as the electrical
energy generator for charging the first electrical storage
mechanism when the engine is connected to drive the ground engaging
drive wheel.
4. The hybrid vehicle assembly of claim 1, wherein the voltage
reducer has a voltage input, which is connected to both the energy
conversion device and the first electrical storage mechanism.
5. The hybrid vehicle assembly of claim 1, wherein the connection
between the engine and the electric motor/generator is mechanically
releasable.
6. The hybrid vehicle assembly of claim 1 and further comprising a
drive shaft, which is coupled to the engine.
7. The hybrid vehicle assembly of claim 6, wherein the drive shaft
is selectively coupled to the engine.
8. The hybrid vehicle assembly of claim 6, wherein the drive shaft
is also coupled to the electric motor.
9. The hybrid vehicle assembly of claim 1 wherein the electric
motor/generator and the energy conversion device are the sole
sources for charging power for the first and second energy storage
mechanisms on the hybrid vehicle assembly.
10. The hybrid vehicle assembly of claim 1 wherein the energy
conversion device comprises an alternator.
11. The hybrid vehicle assembly of claim 1 wherein the energy
conversion device converts between electrical and mechanical
energy.
12. The hybrid vehicle assembly of claim 1 wherein the first and
second electrical storage mechanisms each comprises a battery.
13. A hybrid vehicle comprising: an electric motor and an engine,
both of which are drivably connectable to propel the vehicle; a
first electrical storage mechanism on the vehicle for powering the
electric motor; a single energy conversion device continuously
coupled to the engine for providing a charging power output to the
first electrical storage mechanism whenever the engine is running;
a second electrical storage mechanism on the vehicle for providing
power to vehicle accessories at a lower voltage than the first
electrical storage mechanism; and a voltage reducer having an input
coupled to both the single generator and the first electrical
storage mechanism and having an output coupled to the second
electrical storage mechanism to provide charging power at the lower
voltage to the second electrical storage mechanism.
14. The hybrid vehicle of claim 13 wherein the electric motor is
operable as a generator when the engine is propelling the vehicle
to provide charging power to the first and second electrical
storage mechanisms, the single generator and the electric motor
being the sole sources for charging power on the vehicle.
15. The hybrid vehicle of claim 13 and further comprising: a motor
controller for rotating and controlling the rotational speed of the
electric motor; a process controller coupled to the engine for
varying a rotational speed of the engine so as to be substantially
synchronized with the speed of the electric motor; and a mechanical
connection for connecting the engine to drive at least one ground
engaging drive wheel when the engine speed is substantially
synchronized with the electric motor speed.
16. The hybrid vehicle of claim 15, wherein the electric motor is
switchable to a generator mode, wherein the process controller is
connected to the motor controller to selectively switch the
electric motor to the generator mode for charging the first
electrical storage mechanism when the engine is connected to drive
the ground engaging drive wheel.
17. The hybrid vehicle of claim 13 and further comprising a
connection between the engine and the electric motor, which is
mechanically releasable.
18. The hybrid vehicle of claim 17 and further comprising a drive
shaft, which is selectively coupled to the engine.
19. The hybrid vehicle of claim 18, wherein the drive shaft is also
coupled to the electric motor.
20. The hybrid vehicle of claim 13 and further comprising at least
one ground engaging drive wheel, which is rotatable by the engine
and the electric motor.
21. The hybrid vehicle of claim 13 wherein the single energy
conversion device comprises an alternator.
22. The hybrid vehicle of claim 13 wherein the first electrical
storage mechanism comprises a battery.
23. The hybrid vehicle of claim 13 wherein the second electrical
storage mechanism comprises a battery.
24. A vehicle assembly comprising: an engine, which is drivably
connectable to propel the vehicle assembly; a first electrical
storage mechanism on the vehicle assembly and having a first
voltage; a second electrical storage mechanism on the vehicle
assembly for providing power to vehicle accessories at a second
voltage, which is lower than the first voltage; and an energy
conversion device, which is continuously coupled to the engine and
is coupled to the first electrical storage mechanism; and a voltage
reducer having an input coupled to both the energy conversion
device and the first electrical storage mechanism and having an
output at the second voltage, which is coupled to the second
electrical storage mechanism to provide charging power at the
second voltage to the second electrical storage mechanism.
25. The vehicle assembly of claim 24 wherein the energy conversion
device comprises an alternator.
26. The vehicle assembly of claim 24 wherein the energy conversion
device converts between electrical and mechanical energy.
27. The vehicle assembly of claim 24 wherein the first electrical
storage mechanism comprises a battery.
28. The vehicle assembly of claim 24 wherein the second electrical
storage mechanism comprises a battery.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 10/194,745, which was filed Jul. 12, 2002 and is pending, which
is a continuation of U.S. application Ser. No. 09/483,008, which
was filed Jan. 13, 2000 and issued as U.S. Pat. No. 6,481,516,
which is a continuation of U.S. application Ser. No. 08/705,001,
which was filed Aug. 29, 1996 and issued as U.S. Pat. No.
6,044,922, which is a continuation of application Ser. No.
07/948,288, which was filed Sep. 21, 1992, now abandoned, which is
a continuation-in-part of application Ser. No. 07/880,967 filed
date May 8, 1992, now abandoned.
BACKGROUND OF THE INVENTION
[0002] This invention relates to parallel electric hybrid vehicles
and combined series-parallel electric hybrid vehicles, and in
particular to the location of the component parts.
[0003] There are basically four types of electric propulsion
systems known for vehicles. First, there is a pure electric drive
vehicle. The pure electric drive vehicle has an electric motor
which receives power from a main battery pack via a controller. The
controller controls the speed of the electric motor. The major
disadvantage of a pure electric drive vehicle is that the range is
very limited and the vehicle must be stopped and connected to an
energy source such as an electrical outlet in order to be
recharged.
[0004] The second type of electric propulsion system for vehicles
is a series hybrid system. There are three major components in a
series system: (1) a generator; (2) an electric motor arranged in
series; and (3) an engine powering the generator. Mechanical energy
generated by the engine is converted to electrical energy by the
generator and is then converted back to mechanical energy by the
electric motor. Each process of conversion is afflicted with losses
and subsequent reductions of efficiency which is a significant
disadvantage of this type of system.
[0005] The main advantage of the series hybrid is that it is
possible to operate the engine at a fixed operating point within
its engine speed/torque map. This point can be selected so that the
engine functions with the greatest efficiency or produces
particularly low emissions. Nevertheless, the efficiency of the
entire series hybrid drive system is less than satisfactory.
[0006] The third type of electric propulsion systems is the
parallel hybrid system, as described, for example, in U.S. Pat. No.
5,081,365. Parallel hybrid propulsion systems generally have three
component areas: (1) electrical storage mechanism, such as storage
batteries, ultracapacitors, or a combination thereof; (2) an
electric drive motor, typically powered by the electrical storage
mechanism and used to propel the wheels at least some of the time;
and (3) an engine, such as a liquid fueled engine (e.g., internal
combustion, stirling engine, or turbine engine) typically used to
propel the vehicle directly and/or to recharge the electrical
storage mechanism.
[0007] In parallel hybrid systems, the electric drive motor is
alternatively driven by mechanically coupling it to the engine.
When coupled, the engine propels the vehicle directly and the
electric motor acts as a generator to maintain a desired charge
level in the batteries or the ultracapacitor. While a parallel
hybrid system achieves good fuel economy and performance, it must
operate in an on and off engine parallel mode. In this mode, the
stop-and-go urban driving uses electric power and the engine is
used to supplement existing electric system capacity. For long
trips, when the battery for the electric motor could be depleted,
the vehicle cruises on the small engine and the electric system
will provide the peaking power.
[0008] The primary advantage of the parallel hybrid drive over the
series drive previously described is improved efficiency (lower
fuel consumption) in the engine, since the engine's mechanical
energy is passed directly on to the drive axle. The bulky generator
is no longer required, thereby lowering both the cost and weight of
the vehicle.
[0009] However, with extended stop and go urban driving, the
battery pack will be often depleted and will need a charge in
addition to the charge received from the electric motor. Or, the
engine will be required to power the vehicle during the stop and go
driving period thereby eliminating most beneficial effects of such
an electric system. Therefore, the vehicle with a parallel system
has limited inner city driving capabilities and range.
SUMMARY OF THE INVENTION
[0010] One embodiment of the present invention relates to a hybrid
vehicle assembly. The assembly includes an electric
motor/generator, an engine, a connection between the electric
motor/generator and the engine, first and second electrical storage
mechanisms, an energy conversion device and a voltage reducer. The
electric motor/generator is operable as a motor and as an
electrical energy generator. The first electrical storage mechanism
is connected to the electric motor/generator for selectively
powering the electric motor/generator. The energy conversion device
is continuously connected to the engine. The voltage reducer is
coupled to the first electrical storage mechanism, the energy
conversion device and the second electrical storage mechanism so as
to provide charge from the first electrical storage mechanism, the
energy conversion device and the electrical energy generator to the
second electrical storage mechanism.
[0011] Another embodiment of the present invention relates to a
hybrid vehicle. The hybrid vehicle includes an electric motor, an
engine, first and second electrical storage mechanisms, a single
energy conversion device and a voltage reducer. The electric motor
and the engine are both drivably connectable to propel the vehicle.
The first electrical storage mechanism powers the electric motor.
The single energy conversion device is continuously coupled to the
engine for providing a charging power output to the first
electrical storage mechanism whenever the engine is running. The
second electrical storage mechanism provides power to vehicle
accessories at a lower voltage than the first electrical storage
mechanism. The voltage reducer has an input coupled to both the
single generator and the first electrical storage mechanism and has
an output coupled to the second electrical storage mechanism to
provide charging power at the lower voltage to the second
electrical storage mechanism.
[0012] Another embodiment of the present invention relates to a
vehicle assembly. The vehicle assembly includes an engine, first
and second electrical storage mechanisms, an energy conversion
device and a voltage reducer. The engine is drivably connectable to
propel the vehicle assembly. The first electrical storage mechanism
has a first voltage. The second electrical storage mechanism
provides power to vehicle accessories at a second voltage, which is
lower than the first voltage. The energy conversion device is
continuously coupled to the engine and is coupled to the first
electrical storage mechanism. The voltage reducer has an input
coupled to both the energy conversion device and the first
electrical storage mechanism and has an output at the second
voltage, which is coupled to the second electrical storage
mechanism to provide charging power at the second voltage to the
second electrical storage mechanism.
[0013] Due to the innate, but separate, advantages of both the
series and the parallel drives, the above embodiments form combined
series and parallel systems. In one embodiment, the engine has an
alternator or generator connected directly to the engine's drive
shaft by some mechanism, for example, a fan belt. Generally,
alternators or generators are used to charge the battery of a
vehicle's accessory systems, such as the lights, fans, etc. These
systems typically operate on twelve (12) volts. However, the
inventor of the present invention realized that the alternator is
very capable of high current/high voltage output, ranging from, but
not limited to, approximately ten (10) volts to in excess of one
hundred fifty (150) volts. In standard applications, such as
vehicle accessory systems, voltage output is regulated to
approximately fourteen (14) volts. Implementation of some
embodiments of this invention allows for efficient usage of the
upper limits of the alternator's output capacity. Voltage output
can be controlled by a central process controller, which directs
excess current to the parallel system vehicle's main storage
battery pack. Voltage output can be varied to the appropriate
levels by regulating the field current, among other methods of
control.
[0014] The alternator can be set to a continuous high voltage
level, matching that of the hybrid's main battery pack. A switching
power supply could then channel generated current into the main
battery pack, or into the vehicle's twelve volt battery. The
switching power supply has the ability to reduce voltage to the
appropriate level, based upon which electrical system is being fed.
Alternatively, the power supply can be configured as a voltage
reducer to reduce the voltage output from the alternator for the
vehicle's twelve-volt battery.
[0015] This arrangement eliminates the main disadvantage of
conventional parallel hybrid designs as used in a vehicle. It has
been found that at slow speed, such as stop and go urban driving,
the parallel system will allow the main storage battery pack to
deplete its energy below a comfortable and usable level of charge.
A series hybrid system is more adaptable to urban driving because
it constantly funnels limited amounts of electrical energy back
into the system's battery pack. The main negative of a series
hybrid system is that it does not permit an adequate charging level
to sustain the high energy demand associated with long term, high
speed driving. The above-embodiments of the present invention
prevent depletion of the battery pack by better utilizing the
existing component structure typically associated with parallel
hybrid systems.
[0016] Prior hybrid propulsion systems were capable of operating in
one or more of the following modes, but not necessarily in all of
them: (1) a series hybrid, which is plugged in for recharge, and
which uses the engine as a "range extender" when the electrical
storage mechanism is depleted, and/or (2) a series hybrid which
runs the engine in order to recharge its own electrical storage
mechanism, typically via a generator/alternator, and/or (3) a
parallel hybrid, which is plugged in for recharge, and which uses
the engine and/or the electric motor either separately or in
unison, depending upon conditions, circumstances, and the process
controller, in order to directly power the vehicle, and/or (4) a
parallel hybrid similar to the one described in (3), directly
above, but which recharges its own electrical storage system via
the engine and, typically, a generator/alternator (see U.S. Pat.
No. 5,081,365). Each of these modes has its benefits and drawbacks,
depending on circumstances, thus the industry is involved in debate
over which system is the most promising.
[0017] The purpose of the series-parallel functionality is to
overcome problems inherent to either concept when employed
individually. The advantages are increased range in the urban
driving mode and a secondary method of range extension in highway
mode without significantly increasing the bulk or cost of the base
parallel system. In addition, the control of the operation of the
drive motor is more versatile and efficient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a block diagram of the power train and the
controls for a series-parallel vehicle;
[0019] FIG. 2 is a block diagram of the power train and the
controls for a vehicle incorporating an additional embodiment of
the series-parallel vehicle; and
[0020] FIG. 3 is a block diagram showing the relative location of
the electric and internal combustion motors in relationship to the
vehicle, according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] FIG. 1 is an embodiment usable with the present invention.
FIG. 1 illustrates in block diagram form an electric parallel
hybrid vehicle power train and controls. An example of an electric
hybrid vehicle power train is described, for example, in U.S. Pat.
No. 5,081,365 which was patented by an inventor of the present
invention and which patent is incorporated herein by reference.
[0022] The parallel hybrid system 10 includes a battery pack 18, an
electric drive motor 16 powered by the battery pack 18 and an
engine 24. A process controller 22 determines the prime mover of
the vehicle, i.e., whether the electric motor 16 powers the
vehicle, or the engine 24 drives the vehicle, or both the electric
motor 16 and the engine 24 drive the vehicle.
[0023] The electric hybrid power train and its related controls 10
includes ground engaging wheels 12. The wheels 12 could be either
the rear wheels or the front wheels of the vehicle. In addition, it
is within the scope of the present invention to have the drive
wheels be part of a four-wheel drive system or a three-wheel
tricycle. Only one drive wheel is necessary.
[0024] The drive wheels 12 are connected by a drive axle 13 to a
differential 14, the housing of the differential 14 being attached
to a housing of a transmission (not shown). The transmission is
controlled in a conventional manner by a gear shift lever (not
shown) and a foot-operated clutch such as the foot-operated 48
clutch shown in FIG. 3. The foot-operated clutch, gear shift lever,
transmission, differential 14, drive wheels 12 and manner of
connecting the drive wheels 12 to the differential 14 are
conventional to a standard motor vehicle.
[0025] As mentioned above, the electric hybrid power train 10
includes an electric motor 16 which is one of two prime movers of
the vehicle. The electric motor 16 is preferably a 40 HP 96-volt
permanent magnet or compound wound DC motor.
[0026] The 96-volt battery pack 18 preferably consists of eight (8)
12-volt batteries in series is connected to the electric motor 16.
If desired, a conductor plug (not shown) may be connected to cross
the battery pack 18 to connect the batteries in the battery pack 18
to an off-board battery charger. Such a mechanism for recharging
the batteries may be desirable at times, though under most
conditions, it will not be needed due to the on-board charging
capability of the present system, as described below.
[0027] The 96-volt motor 16 and 96-volt battery pack 18 are not the
only type that could be used. Indeed, a higher voltage motor and
battery pack could give advantages in component weight and
efficiency. It should be noted that the motor size and battery
capacity are parameters that would in fact vary with the chosen
vehicle weight and size.
[0028] A transistorized motor speed controller 20 is positioned
between the electric motor 16 and the battery pack 18 and controls
the current flow to the electric motor 16. The motor controller 20
is the link between the process controller 22 and the electric
motor 16. The process controller 22, as described above, signals
the motor controller 20 which disengages the current flowing from
the battery pack 18 to the electric motor 16 or creates a generator
from the electric motor 16 to charge the battery pack 18.
[0029] The motor controller 20 as used in one embodiment of the
present invention can be a commercially available pulse width
modulation type such as, for example, one made by Curtis PMC of
Dublin, Calif. The motor controller 20 regulates an array of
parallel power MOSFET transistors to vary the average current to
the electric motor 16 in response to a signal from the process
controller 22.
[0030] At 24, is illustrated an internal combustion engine, which
is the second prime mover of the vehicle. The engine is located in
the end of the vehicle opposite the electric motor 16 as shown in
FIG. 3. The engine 24 is preferably a 16-hp diesel engine, but it
could be a spark ignition engine, turbine, or any other practical
prime mover. For convenience in this discussion, it will be
referred to as a diesel engine.
[0031] During acceleration of the vehicle, it is preferred that
only the electric motor 16 drives the wheels 12. An electric clutch
26 positioned between the electric motor 16 and the engine 24 will
allow the engine 24 to assist in driving the wheels 12 if the
process controller 22 determines that the electric motor 16 needs
assistance. Basically, such a situation arises if the process
controller 22 determines that the electric motor 16 is not capable
of accelerating the vehicle, such as accelerating up a steep
incline. If such is the case, the process controller 22 will cause
the engine 24 to be brought on line, as described below, to assist
in driving the vehicle. While the engine 24 will assist the
electric motor 16 if needed, it is not desirable to use the engine
24 in this fashion since accelerating the vehicle with the engine
24 burns much fuel thereby decreasing fuel economy and increasing
potential pollution.
[0032] After the vehicle has accelerated using the electric motor
16 and the electric motor 16 reaches a predetermined speed (rpm)
without the assistance of the engine 24, the process controller 22
will cause the engine 24 to start or rev to get the engine 24 to
approximately the same speed as the electric motor 16, i.e., within
1% of the electric motor's rpm. Once the engine 24 achieves the
required approximately equal rpm, the electric clutch 26 activates
such that the engine 24 also drives the wheels 12. While the
electric motor 16 remains on line to drive the vehicle, the
electric motor 16 is generally not needed in this capacity.
Therefore, the process controller 22 switches the electric motor 16
into a generator. The process controller 22 controls the amount of
current the electric motor 16 is capable of putting out and in that
time puts energy back into the battery pack 18. For example, during
an acceleration up to approximately 40 to 50 m.p.h. on the electric
motor 16 only, it will take approximately 1 1/2 to 2 minutes to put
that energy back in the battery pack.
[0033] If at any time during the driving of the vehicle, after the
acceleration period, the process controller 22 senses that extra
power is needed to maintain a constant speed, such as accelerating
to pass or climbing a steep incline, the process controller 22 will
signal the motor controller 20 to activate the electric motor 16 to
assist the engine 24. Basically, if the process controller 22
determines that the engine 24 needs additional power or rpm, the
electric motor 16 is brought on line to assist in driving the
wheels 12. In a standard vehicle, if the foot pedal is depressed to
a certain point, the speed of the vehicle will be directly
dependant on whether the vehicle is on a flat surface or an
incline. With the vehicle of one embodiment of the present
invention, if the foot pedal is depressed to a certain point, the
speed of the vehicle will be at a certain predetermined speed,
regardless of whether the vehicle is travelling on a flat surface
or an incline. Therefore, if the engine 24 is not capable of
maintaining the speed of the vehicle, the process controller 22
will activate the electric motor 16 to assist in driving the
vehicle. Once that extra assistance is no longer needed, the
process controller 22 will signal the motor controller 20 to cease
the supply of electricity coming from battery pack 18 to the
electric motor 16 and cause the electric motor 16 to operate as a
generator to charge the battery pack 18.
[0034] Preferably, the electric clutch 26 is of any type which is
capable of being engaged or released at will such as an AT clutch
by Warner Electric, a subsidiary of DANA. When engaged, the
electric clutch 26 couples the engine 24 to the input shaft of a
transfer case (not shown), which is preferably a belt drive, but
may be a gear or chain drive. Space permitting, the output shaft of
the engine 24 could be aligned with the shaft of the electric motor
16 and the electric clutch 26 could selectively couple the engine
24 and the electric motor 16 directly without any need for a
transfer case.
[0035] It will also be understood that requirements of available
space in the vehicle might dictate some other configuration for
selectively coupling the engine 24 to the electric motor 16. For
example, a third shaft with a transfer case on each end of the
shaft might be needed. It is within the scope of the present
invention to cover any configuration required, so long as the
engine 24 is coupled to the electric motor 16, through mechanism
which may be engaged to release at will. The electric clutch 26 is
a preferred device for this purpose due to the ease of controlling
it, but other mechanism could be employed, such as a centrifugal
clutch and pneumatic clutches.
[0036] The engine 24 is equipped with and drives an alternator 28,
such as a Motorola 150A alternator DC power unit which is capable
of high current/high voltage output, ranging from but not limited
to, approximately 10 volts to an excess of 150 volts. In standard
applications, such as vehicle accessory systems, voltage output is
regulated to approximately 14-volts. The 14-volt output of the
alternator 28 charges an accessory battery 30 which may be a single
heavy duty 12-volt automotive battery. A group of accessories,
which the accessory battery 30 controls and powers, includes such
conventional automotive equipment as horn, lights, windshield
wiper, etc. In addition, engine 24 also has a conventional starting
motor (not shown) activated by a starter solenoid and powered by
the accessory battery 30.
[0037] In accordance with one embodiment of the present invention,
the alternator is additionally connected to the battery pack 18. In
order to charge the battery pack 18, the voltage output of the
alternator 28 must be compatible to charge the battery pack 18.
Therefore, the process controller 22 includes a regulator control
34 which controls the voltage output of the alternator 28. The
regulator control 34 adjusts the voltage of the alternator from a
voltage compatible to charge the accessory battery 30 to a voltage
compatible to charge the battery pack 18 and back to the voltage
compatible to charge the accessory battery 30. Typically, the
voltage compatible to charge the battery pack 18 is substantially
greater than the voltage compatible to charge the accessory battery
30.
[0038] The regulator control 34 is actually part of the process
controller 22 such that when the accessory battery 30 is completely
charged, the process controller 22 will initiate the regulator
control 34 to adjust the voltage upward and charge the battery pack
18. As mentioned, the battery pack 18 has a typically much higher
voltage than that of the accessory battery 30. The voltage output
of the alternator 28 is adjusted by the regulator control 34 to
match the requirements of the accessory battery 30, which receives
the highest priority in the voltage flow hierarchy as will be
described below. Excess capacity, already at a compatible higher
voltage level, is then made available to the battery pack 18 on a
secondary priority level.
[0039] In the preferred embodiment, the actual switching of the
voltage path from the alternator 28 to the accessory battery 30 and
the battery pack 18 is accomplished through a switching mechanism
32. The switching mechanism 32 is positioned between the alternator
28 and the accessory battery 30 and the battery pack 18. The
switching mechanism 32 receives signals from the process controller
22 directing the voltage output of the alternator 28 to either the
accessory battery 30 or to the battery pack 18 depending on the
signal from the process controller 22.
[0040] In the preferred embodiment, the alternator 28 will have a
voltage output of approximately 14-volts when charging the
accessory battery 30 and a voltage output of approximately 90-volts
when charging the battery pack 18. Once the accessory battery 30
has been completely charged, the process controller 22 will
increase the voltage output of the alternator 28 and will also
signal the switching mechanism 32 to switch the path of the voltage
from the accessory battery 30 to the battery pack 18. Thereafter,
the voltage output of the alternator 28 will be directed to the
battery pack 18 until the accessory battery 30 requires recharging.
Thereupon, the process controller 22 will alter the voltage output
of the alternator 28 to a suitable lower voltage and signal the
switching mechanism 32 to begin directing the voltage to the
accessory battery 30. This process will occur until once again, the
accessory battery 30 is completely charged.
[0041] Another embodiment of the present invention is referred to
in FIG. 2. For ease of understanding, like elements will be
referred to with like reference characters.
[0042] As best illustrated in FIG. 2, the voltage output from the
alternator 28 would be directed directly into the battery pack 18.
In this embodiment, the process controller 22 and the switching
mechanism 32 are not required. The voltage output would be preset
at an approximate constant amount. A power supply 36 connected to
receive some of the output voltage of the alternator reduces that
portion of the voltage output of the alternator 28 such that the
accessory battery 30 would also receive a compatible voltage.
[0043] FIG. 3 illustrates the specific location of the electric
motor 16 and the combustion engine 24 with respect to the vehicle.
The internal combustion engine 24 is located in one end portion 38
of the vehicle. The engine 24 is joined to a small diameter
composite drive shaft 40 such as the one described sold by H and R
Composites, Inc. as described above, which is incorporated herein
by reference. The drive shaft 40 is connected to the electric motor
16 via the fly wheel 42 and the electric clutch 26. The electric
motor 16 is located in the end portion 44 of the vehicle opposite
the end portion 38. Note the end portion 44 may be the front
portion of the vehicle where motors are located in standard
vehicles or the end portion 44 may be the area where the trunk is
located in standard vehicles. Additionally, the vehicle may be
front wheel or rear wheel drive regardless of whether the electric
motor 16 is in the front or rear end of the vehicle. Preferably,
the electric motor 16 is located in the front of the vehicle when
the vehicle has front wheel drive and in the rear of the vehicle
when the vehicle has rear wheel drive. Thus, either the wheels 12a
or the wheels 12b may be the drive wheels. The electric motor 16 is
connected to a transaxle 46 via a foot operated clutch 48. The
transaxle 46 may be a four-speed transaxle.
[0044] The design shown in FIG. 3, provides several distinct
advantages. The design has little mechanical complexity, provides
spacing between the component parts, and allows easy access to the
component parts. These features simplify manufacturing and
maintenance work. The design also teaches a system that can be
adapted to almost any internal combustion engine in any car. The
design provides good weight distribution in the vehicle. And the
design uses a light weight drive shaft, to help minimize the
overall weight of the vehicle.
[0045] It can be seen that any series hybrid or parallel hybrid
vehicle can be adapted to use the preferred embodiment of the
present invention. First, regardless of the hybrid type, a high
voltage alternator can be placed (or may already exist) in the
vehicle. The high voltage alternator is then connected to the
battery pack of the electric motor. A voltage reducer can be
connected to the accessory battery to prevent the accessory battery
from receiving an incompatible voltage. Then, so long as the engine
is running, the battery pack will be recharging always ready to
supply electric power to the electric motor regardless of whether a
motorist is driving in the city or on the open highway.
[0046] Although the present invention has been described with
reference to preferred embodiments, workers skilled in the art will
recognize that changes may be made in form and detail without
departing from the spirit and scope of the invention.
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