Considering the cost savings involved with building transmissions with only three shifting parts, you’ll realize why car companies have grown to be very interested in CVTs lately.
All of this may sound complicated, but it isn’t. Theoretically, a CVT is far less complex than a normal automated transmission. A planetary gear automatic transmission – sold in the tens of millions this past year – has a huge selection of finely machined shifting parts. It has wearable friction bands and elaborate digital and hydraulic settings. A CVT just like the one explained above has three simple shifting parts: the belt and both pulleys.
There’s another advantage: The cheapest and highest Variable Speed Transmission ratios are also further apart than they would be in a typical step-gear tranny, giving the transmitting a greater “ratio spread” This implies it is a lot more flexible.
The engine can always run at the optimum speed for power or for fuel economy, whatever the wheel speed, which means no revving up or down with each gear change, and the ideal rpm for the proper speed constantly.
As a result, instead of five or six ratios, you get an infinite number of ratios between the lowest (smallest-diameter pulley setting) and highest (largest-diameter pulley environment).
Here’s an example: When you start from an end, the control pc de-clamps the insight pulley so the belt turns the tiniest diameter while the output pulley (which goes to the wheels) clamps tighter to help make the belt convert its largest diameter. This produces the lowest gear ratio (say, 3.0-to-1) for the quickest acceleration. As speed builds, the pc varies the pulley diameters, as conditions dictate, to get the best balance of fuel economic climate and power.