| Continuously variable transmissions (CVTs) have an infinitely variable ratio, which allows the engine to operate more time in the optimum range given an appropriate control of the engine valve throttle opening and transmission ratio. Usually CVTs are used in small vehicles due to power limitations. Continuously variable power split transmissions (CVPST) were developed in order to reduce the fraction of power passing through the variable elements.; In this thesis a conceptual design for a CVPST for a hybrid-electric vehicle (HEV) is presented, with increased power envelope in the system for a sport utility vehicle (SUV) application. A LabVIEW® program has been developed, which provides engine-vehicle velocity relationships, CVT ratio, variable pulley radii, belt force and power trace following the ideal fuel consumption curve. This thesis aims at extending CVT applications in the automotive industry to bigger vehicles (and engines) such as pickup trucks and small buses. |
