pic: CVT drivetrain

[ahecht]

Originally Posted by cdr1122334455

yeah, Contiunously Variable Transmissions are great. You may want to check this white paper out, from the great team of 217. Do keep in mind its patent pending. I believe they were one of the first teams to try out a CVT, and they were very succesful with it, it's great to be able to have full horsepower at any speed.

Also, CVT's are starting to be used in cars too. The 2005 Ford Freestyle is running with a CVT transmission, pretty cool.

While the CCT was a very innovative transmission, it was not a CVT (if I remember correctly, the CCT was actually a single speed transmission for blending two motors).

Torroidal CVTs, such as the one in your pictures, were used by 190 in 2002 (and our 2003 bot was designed to use a 2nd Generation CVT, but we ran out of time). I know that plans were made available to the FIRST community at the time, but I don't know if a formal whitepaper was ever produced. I'll try to find out.

There are many other types of CVTs out there that would probably be easier to build (the toroidal transmission requires several parts that need to be done by CNC). The Freestyle that you mentioned, like most cars with CVTs, uses a chain that runs in between two sets of two conical pullies. I don't think anyone has tried this type of transmission on a FIRST robot.