Configuration Synthesis of Novel Series-Parallel Hybrid Transmission Systems with Eight-Link Ravigneaux Mechanisms

Hybrid electric vehicle (HEV) has been invented and developed over the past two decades. It is the promising solution for cutting down emission and reducing pollution besides electric vehicles. Since a series hybrid vehicle needs no transmission, the transmissions of parallel and series-parallel hybrid systems are studied nowadays. This paper presents a design approach for the configuration synthesis of series-parallel hybrid transmissions with the eight-link Ravigneaux mechanisms. The synthesis process subject to the concluded design consist of 7 mechanisms with eight members and twelve joints including the combination of two planetary gear trains. Then, by using the techniques of power and clutch arrangements, new series-parallel hybrid transmissions are synthesized with 27 clutchless hybrid systems and 27 corresponding series-parallel hybrid transmissions. A new hybrid transmission is selected as an example to demonstrate the feasibility of the synthesized configurations by analyzing the working principle with operation modes and power flow paths.