A prototype of the Naudic iCVT (Incremental Continuously Variable Transmission) has been tested to 600 N.m input torque in a Porsche 924 turbo. The transmission, which features 64 ratios that shift under load without any clutch action, is positively driven at all times.
This is the world's first CVT-type transmission to accomplish a positive drive even when shifting and the first time a prototype of such a gearbox has been successfully tested in an actual vehicle.

Barlworld CVT Technologies' MD and Naudic iCVT inventor, Dr Jan Naude, says that the 600 N.m input torque was achieved solely through a positively linked mechanical drive.

"This gearbox does not rely on any form of friction drive whatsoever resulting in one of its main advantages, which is that it can be scaled up or down for almost any application exactly in the same way as a manual transmission, but with CVT capability," says Dr Naude.

He adds that most of the so-called positive drive CVT's in existence do provide a sort of positive drive but rely on roller clutches (sprags) or spring-loaded teeth to engage the drive, which is problematic in high torque and high speed applications. These types of CVT's usually end up being used for very low speed applications like, for example, in bicycles.

Barloworld CVT Technologies is an Intellectual Property (IP) company which sells licenses to interested parties to evaluate and manufacture its concepts.

Anyone interested in test driving the iCVT vehicle is encouraged to contact the company. Contact details