Allison, Dana License Novel CV Technology

Allison Transmission Holdings Inc. and Dana Holding Corp. have agreed to commercialize a new continuously variable transmission for cars, trucks and off-road equipment.

The companies will help develop Fallbrook Technologies Inc.'s "NuVinci" CV system, which uses a ring of balls between rotating plates to transmit power. The San Diego, Calif.-based developer says its transmission design is simpler, less costly to manufacture and can be easily adapted and scaled to handle a broad range of torque.

Allison has exclusive rights to apply Fallbrook's technology to commercial vehicle, military, stationary equipment and certain off-road markets. Dana has exclusive rights to develop Fallbrook-based powertrain systems for cars and some off-road applications.

Under a separate agreement, Dana will have exclusive license to supply NuVinci-based transmission components to Allison.

Fallbrook's planetary CVT clamps a ring of three to 12 large balls between input and output disks. The balls roll on an idler hub that keeps them in position. Tilting the axis of the balls relative to the axis of the transmission and shifting them slightly forward or back along the transmission axis changes the contact diameters of the balls relative to the two drive disks.

The system transfers torque from disk to ball to disk through a traction fluid that fills the transmission case. The liquid solidifies under pressure as it is squeezed between the balls and disks, providing an efficient, near-mechanical transfer medium.

Fallbrook began as Motion Systems Inc. in 1998 and introduced its first transmission for bicycles and light electric vehicles in 2006. The company says its CVT can be tailored to a huge range of applications from bicycles to wind turbines and variable-speed superchargers to wind turbines.