The inventive parallel drive system is particularly well suited to be supported
at the axle of the vehicle. A coupling arrangement includes a clutching mechanism
and a gear reduction device that selectively couple an electric motor to the drive
wheels for providing torque to the wheels alone or in combination with input from
an internal combustion engine. The drive torque can also be provided exclusively
from the internal combustion engine. The inventive arrangement also allows for
the electric motor to be used as a generator during coasting or braking, for example.