Nissan shows Hi-Cross Concept 7-passenger 4WD hybrid in Geneva; another implementation of “one-motor, two-clutch” system
|The Hi-Cross Concept hybrid. Click to enlarge.|
Nissan unveiled the Hi-Cross Concept hybrid at the 2012 Geneva Motor Show, heralding a possible new design direction for the company as well as a possible expansion of the current Juke-Qashqai-Murano portfolio.
Despite its modest external proportions, Hi-Cross Concept has a space-efficient interior with three rows of seats for seven passengers. The hybrid drivetrain couples an electric motor powered by a Nissan-developed compact lithium-ion battery with a 2.0-liter gasoline direct injection engine to provide the performance potential of a 2.5-liter with the economy and emissions expected from a much smaller unit.
For the concept, the HEV drivetrain is based on new technology developed by Nissan for front-wheel drive models—itself adapted from the hybrid system developed for the RWD Infiniti M35h—but modified to provide four-wheel drive. The new system adopts the “one-motor, two clutch” (1M2CL) technology linked to Nissan’s new generation XTRONIC continuously variable transmission which by itself achieves a 10% improvement in fuel economy over comparable previous generation CVTs. (Earlier post.) The low friction design has smaller shaft-diameter pulleys with a new belt to give the widest possible ratio coverage for enhanced efficiency.
The 1M2CL system installs the first clutch between the naturally-aspirated 3.5-liter V6 and the electric motor. This clutch allows the full decoupling of the V6 when the systems is in either electric or power regeneration modes, thereby reducing mechanical drag and boosting the efficiency of the electric motor. The second clutch transmits the drive force. (Earlier post.)
The hybrid drivetrain makes extensive use of battery technology developed for the Nissan LEAF. The high output, fast-charging compact lithium-ion battery, linked to high-level motor control technology, provides acceleration assist when needed and permits downsizing of the gasoline engine for optimum economy and emissions.
In city driving, the presence of the electric motor and lithium-ion battery allow the engine to be turned off frequently. It can also be disengaged completely with the clutch, and energy can be recovered effectively when braking.