State-of-the-Art of CVT-Modelling

The most frequently applied CVT-elements are the chains from LUK, Germany, from Borg-Warner, USA, and the push-belts from VDT-Bosch, Netherlands. The LUK-chain and the VDT-belt have been considered in very much detail at the author’s Institute. Therefore the paper will discuss these two systems with a certain focus on the LUK-chain presenting the latest developments and results, both, of theory and of industrial practice.

For both systems two-dimensional models have been established describing the plane dynamics. For the LUK-chain a three-dimensional model has also been completed, which allows to consider dynamical out-of-plane-effects and, moreover, to optimize a chain with respect to all relevant parameters. The theories have been converted into two computer codes. Comparisons with measurements from industry confirm the models.