US Patent 6887180 Power train with hybrid power source

The power train of a motor vehicle employs a hybrid drive including a combustion engine and an electrical machine. The transmission of the power train is shiftable into different gears in dependency upon the operating conditions of the vehicle. Such conditions include a traction condition when the vehicle is propelled by the engine and/or by the electrical machine, a coasting condition when the vehicle is being decelerated with attendant conversion of kinetic energy into electrical and/or rotational energy and storage of converted energy, a cold starting condition when the cold engine is started by the electrical machine, and a warm starting condition when the hot engine is started by the electrical machine and/or by at least one flywheel.