A continuously variable accessory drive is a device that is designed to optimize the performance of engine-driven accessories.
TRW Automotive and Fallbrook Technologies today announced that they have signed a memorandum of understanding to develop applications for Fallbrook’s continuously variable accessory drive (CVAD) technology for commercial vehicles.
The specific applications covered by the MOU were not disclosed, but are designed to improve both performance and efficiency of vehicle accessories, which could directly increase vehicle fuel efficiency.
Fallbrook believes that CVADs have significant potential to improve accessory performance. The Environmental Protection agency and the National Highway Traffic Safety Administration are in the process of establishing the first ever fuel economy standards for medium and heavy duty trucks and buses starting in 2014, which will cause more research into fuel economy for commercial applications.
Since accessories, including the air conditioner, power steering pump, water pump, or alternator, draw power from the engine, they can hurt a vehicle’s fuel efficiency when they are running at speeds that are above or below their optimum rpm.
The “NuVinci” technology uses a set of rotating and tilting balls positioned between the input and output components of a transmission. Tilting the balls changes their contact diameters and varies the speed ratio. The NuVinci platform can be used in a wide variety of transmission-based vehicles or devices.
A CVAD, which operates between the engine and these accessories, is designed to allow accessory speed to vary according to performance needs independent of the engine speed.
Both companies expect negotiation of a joint development agreement to conclude in 2011.
