CLEAN AUK
TECHNOLOC
\
The organizations that contributed to
the development of the UPS hydraulic
hybrid demonstration vehicles are:
U.S. EPA, UPS, Eaton Corporation, In-
ternational Truck and Engine Corpora-
tion, and the U.S. Army - National
Automotive Center. Major technical
support was provided by FEV Engine
Technology, Inc., Southwest Research
Institute and Morgan-Olson.
FEV ft
>>EPA
United States
Environmental
Protection Ag<
EPA420-F-08-043
June 2006
Office of Air and
iation
H >-
O o
S o
o ->
t- O
D Z
< x
EPA's Clean Automotive Technology Program con-
ducts this innovative research primarily to:
• Achieve ultra-low pollution emissions
• eenhouse gases
• / efficiency
cost-effective technologies, Clean
Automotive Technology also encourages manu-
produce cleaner and more fuel-
efficient vehicles. Fleets and consumers benefit
by being able to recoup the initial hybrid system
costs through lower operating costs within a few
years.
Environmental Protection Agency
U.S. EPA National Vehicle and Fuel
Emissions Laboratory (NVFEL)
2000 Traverwood Drive
Ann Arbor, Ml 48105
Phone: (734) 214-4200
http://www.epa.gov/otaq/technology
COST
EFFECTIVE
HYBRIDS
HYDRAULIC
HYBRIDS
The
Most Efficient
Lowest Cost
Hybrids
** MORGAN
Z> noLSON
World's First Full Series Hydraulic
Hybrid Delivery Vehicle Prototyped in a UPS "Package Car"
http://epa.gov/otaq/technology/tthydraulic
-------
HHV-HYDRAULIC HYBRID VEHICLES
HIGHEST EFFICIENCY - LOWEST COST
Through the use of innovative hydraulic hybrid
technology EPA and its industry partners have
been able to create the most efficient and
cost-effective powertrain technology in the
world. EPA has been able to improve city fuel
economy of a UPS package car by 70% and
reduce CCb greenhouse gas emissions by 40%.
The unique energy recovery technology used
while braking reduces brake wear by 75% in-
creasing the net savings substantially.
A fleet owner operating one of
these high efficiency vehicles
would save up to 1,000 gallons
of fuel each year.
\
What is even more astounding is that the addi-
tional cost for this technology manufactured in
high volume has the potential to be less than
15% of the price of the base vehicle. At cur-
rent fuel prices, this technology will pay for
\^
itself in two to three years.
The net lifetime savings over this
vehicle's typical 20 year lifespan
would be over $50,000.
Hydraulic Hybrid Vehicles (HHVs) rely on
proven innovative technology which can be
applied to light duty work trucks, SUVs and
heavy duty urban vehicles such as city transit
buses and garbage trucks.
HOW IT WORKS
This innovative technology is simple. The main com-
ponents in HHVs are:
• The high pressure accumulator stores energy
as a battery would in a hybrid electric vehicle
using hydraulic fluid to compress nitrogen gas .
• The low pressure reservoir stores the low pres-
sure fluid after it has been used by the pump/
motor.
Engine Pump
High Pressure Accumulator
I
Low Pressure Reservoir
Rear Drive Pump Motor
• The rear drive pump/motor converts the pres-
sure from the hydraulic fluid into rotating
power for the wheels, and recovers braking
energy which is stored in the high pressure
accumulator
• The engine pump/motor pressurizes and trans-
fers hydraulic fluid to the rear drive pump-
motor and/or high pressure accumulator
• The hybrid controller monitors the driver's ac-
celeration and braking, and commands the
hybrid system components.
There are three key design features enabling an
HHVto provide maximum fuel efficiency:
1. Regenerative Braking When stopping the vehi-
cle, the hybrid controller uses the energy from
the wheels by pumping fluid from the low pres-
sure reservoir into the high pressure accumu-
lator. When the vehicle starts accelerating,
this stored energy is used to accelerate the
vehicle. This process recovers and reuses over
70% of the energy normally wasted during
braking.
2. Optimum Engine Control The engine pump pres-
surizes and transfers fluid from the low pres-
sure reservoir to the rear drive pump-motor,
and under certain operating conditions, to the
high pressure accumulator. In the full series
hybrid design, there is no conventional trans-
mission and driveshaft connecting the engine
to the wheels freeing the engine to be oper-
ated at its maximum efficiency "sweet" spot to
achieve optimum vehicle fuel economy.
3. Shutting Engine Off When Not Needed The unique
hybrid design not only allows the engine to be
operated at its maximum efficiency, but also
enables the engine to be completely shut off
during certain stages of operation because it is
activated by the controller only when it is
needed. As a result, in stop and go urban city
driving engine use is cut almost in half.
------- |