What Would DaVinci Drive?

Unveiling the Mystery Behind the Continuously Variable Transmission



Continuously Variable Transmissions

The continuously variable transmission (CVT), although a pretty new innovation to the car industry, the idea has been around since the 15th century when Leonardo Da Vinci sketches his version of a stepless continuously variable transmission. The main advantage and appeal of the CVT is the fact that there are infinite amounts of gear ratios between a maximum and a minimum (there are no gears in the CVT; however the term gear ratio is still used for what it represents). It provides better fuel economy, a smoother drive and more useable power than offered by an automatic transmission.



Figure 4: Da Vinci's Sketch of CVT in 1490
Da Vinci, Leonardo (1490)

Figure 5: Audi VDP CVT cutaway
Gold, Aaron CVT - what the Continuously Variable Transmission is and how CVT works. Retrieved Feb 15, 2007, from About Web site: http://cars.about.com/od/thingsyouneedtoknow/a/CVT.htm

With a CVT you never feel the transmission shift when driving and it changes adapting to the driving conditions.

The CVT operates on many different systems of which there are 3 common types which will be discussed here:

  • The Variable-Diameter System
  • The Toroidal System
  • The Hydrostatic System

Copyright 2007 Steffani Vivani. All Rights Reserved.