December 3, 2011

Lego Continuously Variable Transmission CVT

If you don't understand how the CVT (continuously variable transmission) works at this previous post...

 This creation from Nico71 can explain it perfectly! Just watch the video, all explanation inside!

As he wrote on the video description:
"Based on modified version of Zblj's Transmission. This CVT enables a variation of the speed (and the torque) from 40rpm to 200 (1/5, 1/1) with constant speed for the motor (200rpm). The two mechanical tachometers show respectively the speed of the motor and the speed of the output."

And the rotation of the yellow connector shows when the torque limiter slides.

By the way since the previous CVT post I've found two more examples of cvt gearboxes:

The firs one is made by Sheepo  that uses two conical surfaces concted with a wheel, as some motorcycles do.

The other cvt gearbox is a compact and very smart idea by Rob Stehlik at Robs Lego Design site

"My Lego CVT is a friction drive assembly, and it is really just a quick concept that wouldn't be very practical in real applications."

"These pictures show the full range of the white disk. One of the wheels is the input, and the other is the output. The speed of the output can vary from much slower than the input speed to much faster. Sounds real technical doesn't it? I didn't bother calculating the exact ratios."