Variator loading and control in a V-belt type geared neutral transmission in and around the geared neutral point

Geared neutral transmissions still hold the promise of unparalleled transmission properties. The mechanism eliminates the need for a starting device and auxiliary clutches and gears for reverse. A very good launch feel without the use of a torque converter should be one of the main benefits. When combined with two clutches, resulting in a two-stage split-torque geared neutral transmission, the system can be augmented such that very high overdrive ratio's can be obtained, allowing low engine speeds at intermediate engine power levels to reduce fuel consumption. The mode shift can be carried out with a synchronised clutch. One of the main points of concern is the loading of the V-belt-type variator in and around the geared neutral point. It is the purpose of this paper to address this issue in some detail, taking both slip and torque loss Into account. Variator control and variator loading in and around the geared neutral point will be addressed.