The Turbo Trac Traction Drive CVT

A unique and attractive variator mechanism has been developed by Turbo Trac, Inc. and Southwest Research Institute (SwRI) for initial use in a heavy duty diesel truck application. High efficiency levels have been predicted with analytical models and confirmed with actual test data. Further, this variator incorporates a very stable and simple control system and has extremely high torque capacity. The prototype of the variator mechanism has also been configured with a modified Allison 650 series transmission for use as a series application in a Peterbilt truck, the final configuration will be a split power design. The setup includes a preliminary control system that allows for highway driving. It is emphasized, however, that Allison did not contribute to this design or any of the content of this paper.

This assembly, along with reasonably low manufacturing costs, has demonstrated that this transmission may be a reasonable alternative for automotive and other mobile or industrial applications. This paper will present some of the results of an analytical evaluation of the variator as well as actual efficiency and durability test results of an initial prototype. Further, a brief discussion of the installation of the custom transmission into an actual vehicle is also included.