Considering the financial savings involved in building transmissions with just three moving parts, you’ll understand why car companies have become very thinking about CVTs lately.
All this may audio complicated, nonetheless it isn’t. In theory, a CVT is much less complex when compared to a normal automatic transmission. A planetary equipment automatic transmission – offered in the tens of millions last year – has hundreds of finely machined moving parts. It offers wearable friction bands and elaborate electronic and hydraulic controls. A CVT like the one defined above has three fundamental moving parts: the belt and the two pulleys.
There’s another benefit: The lowest and maximum Variable Speed Transmission ratios are also additional apart than they might be in a conventional step-gear transmitting, giving the tranny a larger “ratio spread” This means it is even more flexible.
The engine can always run at the optimum speed for power or for fuel economy, regardless of the wheel speed, this means no revving up or down with each gear change, and just the right rpm for the right speed continuously.
As a result, rather than five or six ratios, you get thousands of ratios between your lowest (smallest-diameter pulley environment) and highest (largest-diameter pulley setting).
Here’s a good example: When you begin from a stop, the control computer de-clamps the input pulley therefore the belt turns the smallest diameter while the result pulley (which would go to the tires) clamps tighter to make the belt change its largest diameter. This creates the cheapest gear ratio (say, 3.0-to-1) for the quickest acceleration. As acceleration builds, the computer varies the pulley diameters, as conditions dictate, for the best balance of fuel economy and power.