Variomatic

Variomatic is the continuously variable transmission (CVT) of the Dutch car manufacturer DAF, originally developed by Hub van Doorne. It is a stepless, fully-automatic transmission, consisting of a V-shaped drive-belt, and two pulleys, each of two cones, whose effective diameter can be changed so that the "V" belt runs nearer the spindle or nearer the rim, depending on the separation of the cones. These are synchronized so that the belt always remains at the same optimal tension. History The Variomatic was the first commercially successful CVT (as opposed to shifting between separate gears). In theory, this always produces the optimum torque. The Variomatic was introduced by DAF in 1958, also putting an automatic gearbox in the Netherlands for the first time. The Variomatic was introduced on the DAF 600. Efficiency Because most of the time the engine runs at its most economical speed, the fuel consumption of this car was acceptable, although the fuel efficiency of any mechanical CVT is about 70% (then) to 75% now (Bosch) (now). Reversing Because the system does not have separate gears, but one (continuously shifting) gear and a separate 'reverse mode' (as opposed to reverse gear), the transmission works in reverse as well, giving it the side effect that one can drive backwards as fast as forwards. As a result, in the former Dutch annual backward driving world championship, the DAFs had to be put in a separate competition because no other car could keep up. Thus, these very cheap and simple cars were the 'formula one' in this competition.