Drive clutch for a series hybrid vehicle

A clutch mechanism (20) is disclosed for use with a hybrid electric vehicle (22) wherein the electric motor-generator (26) and engine (24) are arranged in a series configuration. The clutch mechanism (20) is positioned between and in communication with the electric motor-generator (26) and engine (24) to allow for either direct drive or a predetermined gear ratio between the electric motor-generator (26) and engine (24). The electric motor-generator (26) is preferably an integrated electric motor and generator. The engine (24) is preferably a combustion engine.