Abstract
The twin track toroidal variator is usually configured with the engine driven input connected to its supporting shaft; the variator output is then taken from the centre disc assembly. Connection between the variator and the downstream transmission components must therefore pass around the rollers located in the intervening toroidal track. To date, each powe roller has been controlled from a hydraulic cylinder mounted on the transmission casing. The variator output is thereby obstructed and must be provided via a secondary drive arranged to avoid the obstruction. Parallel layshaft or complex epicyclic solutions have been evolved both of which impact the overall transmission efficiency, packaging and resulting complexity. The ERC roller control system eliminates the problem at source allowing a simple drum connection resulting complexity. The ERC roller control system eliminates the problem at source allowing a simple drum connection out of the variator. Comparing the performance of the full toroidal ERC variator with a half toroidal layshaft unit shows comparable efficiency with improved packaging and less complexity.
Keywords: Variator, Efficiency, Full-toroidal, Half-toroidal, Epicyclic