Abstract
In-Wheel Motor drive units have been developed since 1990's. The motor output has 10 times more than the first assist drive unit in the rear for FF vehicle. But it is still much difficult to install a motor in the space of the wheel. The development of a new drive unit has been started for good installability of a motor in many kinds of suspensions. The reduction mechanism is the combination of planetary gears and counter gears that enables to offset the motor axis from the tire axis. Thus, the motor can coexist with suspension arms and brake caliper. The increase of unsprung mass with 40kW motor incl. cooling and lubrication system is +23%.
