|
Chrysler’s new dual-clutch transmission—developed in
partnership with Getrag—makes its debut in 2008. The new technology—available in
Australia on the all-new Dodge Journey—will provide consumers a fuel economy
improvement and CO2 emissions reduction of 6 percent.
“Chrysler’s new dual-clutch transmission is the next step in
transmission technology, offering consumers improved fuel economy along with
smoother and quicker shifting,” said Frank Klegon, Executive Vice President –
Product Development. “This important technology is one of several initiatives we
have in place to directly focus on improving fuel efficiency across our vehicle
line-up.”
Dual-clutch Transmission Technology
Chrysler’s dual-clutch transmission technology improves fuel economy and CO2
emissions by reducing parasitic losses—first, by eliminating the torque
converter, and second, through the use of synchronizers instead of shift
clutches.
In its first Chrysler LLC vehicle applications, the new
dual-clutch transmission will debut in international markets on the all-new 2008
Dodge Journey when mated to the turbo diesel variant.
The dual-clutch transmission is an automatic transmission
which utilises dual launch and shift clutches with a manual transmission style
lay-shaft gear arrangement, instead of a conventional torque converter and
planetary gears. One clutch drives the odd numbered gears and reverse, while the
other clutch drives the even numbered gears. During shifts, the next gear is
anticipated and pre-selected. Then one clutch is opened while the other is
closed, allowing shifting without torque interruption. The result is quicker
acceleration and refined shift quality. Further, with the lay-shaft arrangement
of gears, there is increased flexibility to optimise gear ratio selection for
performance and fuel economy.
The all-new dual-clutch transmission does not require a torque
converter to transfer engine torque to the transmission. Instead, it uses two
wet multi-plate clutches. With the wet multi-plate clutch system, the clutch
components are bathed in lubricating/cooling fluid in order to provide adequate
thermal capacity.
The wet multi-plate clutch system uses hydraulic pressure to
actuate the clutches and provide for gear selection. With this system, the power
flow from the engine to the transmission is not interrupted during a shift,
resulting in a power-on shift. This means that there is less torque disturbance
than a conventional planetary automatic transmission with torque converter.
Also, by eliminating the torque converter and reducing the number of shift
clutches, parasitic losses are reduced leading to improved fuel economy.
|
