PURPOSE: To provide an electric motor, designed to be a power source, with the function of generator or starter motor.

CONSTITUTION: When an combustion engine E is driven with an input clutch C1 set to ON, the output of the engine operate an electric motor M as a generator to charge a battery (not shown in the Figure). When the electric motor M is operated with the input clutch C1 ON as the combustion engine E keeps off, the output of the electric motor E starts operating the engine E. In either case, because a direct clutch C2 and brake B are released, the engine output is transmitted to neither the drive wheels 33a nor 33b. Thus, a vehicle does not run. Because the direct clutch C2, etc., are transmission elements, no major design changes, etc., are required when providing the electric motor with the above function.