In
its second simulation, Schaeffler tested a sport utility vehicle (SUV) equipped
with a 3-liter V6 engine. While the conventional vehicle features an eight-speed
planetary transmission, the electrified version is equipped with a 24 kW
electric motor installed in a five-speed automatic transmission. The fuel
economy improvement achieved in the WLTC is 14 percent in this case, but
significant savings can also be achieved even without electrification.
"The
optimization of the internal combustion engine therefore remains immensely
important for Schaeffler," explained Gutzmer.
As
an example, he demonstrated how the use of a fully-variable valve train allows
fuel consumption to be influenced by changing the opening and closing times of
the valves. The engine can thus be operated without throttling at low loads,
which reduces fuel consumption by more than eight percent at specific operating
points. At high loads, lengthening the intake valve opening time allows the
tendency towards knocking and the need for enrichment to be reduced. Further
savings could be achieved in all relevant operating ranges through the use of
variable compression.
"When
it comes to energy efficiency, variability pays off," explained Gutzmer.
"However, it must always be assessed together with the number of gears, the
degree of electrification, and the system costs."
Electrification
allows a greater number of drive architectures to be achieved. "Because of the
wide variety of possible combinations, the automotive industry is under
increasing pressure to provide an answer to the question of which drive
architecture is the right one," said Gutzmer.
As an automotive supplier, Schaeffler develops technical
solutions that allow the overall level of efficiency of the drivetrain to be
increased. These include components and systems for modern high-efficiency
engines with a high power density, as well as clutches and bearings for
transmissions. Schaeffler also makes efficient electrification possible at every
voltage level, from 48-volt hybrids through to plug-in hybrids with high-voltage
technology.
VIENNA, May 7,
2015 /PRNewswire/
-- In the future, engine and transmission developers will have to work more
closely together to achieve significant improvements in fuel economy. In his
opening speech at the 36th International Vienna Motor Symposium, Prof.
Dr.-Ing. Peter
Gutzmer, deputy CEO of
Schaeffler AG, called on them to do just that. "We must consider internal
combustion engines, electrical components, and transmissions as a whole," he
told the audience of more than 1,000 participants.
Experts
from Schaeffler carried out simulations to demonstrate how the ongoing
electrification and transmission design processes influence one another. The
first calculation compares a C-segment vehicle with and without a 48-volt hybrid
system, respectively. The 1.4-liter gasoline engine is identical in both cases
but, while the non-electrified vehicle features a seven-speed transmission, the
48-volt hybrid has only four gears. The use of this electrified transmission
provides a fuel economy improvement of 18 percent in the WLTC (Worldwide
harmonized Light Vehicles Test Cycle), which will apply in the future.
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