Development of Electric Motor for Electric Motorcycle for Business Use 2011-32-0560

A new DC brushless motor, which has an almost equivalent driving performance to a 50 cm₃ scooter engine, has been developed to be used in a new electric motorcycle for business. The traction motor is compact enough to be mounted close to the driveshaft of the transmission, which helps reduce friction in the drive train.

Consequently, in the downsized motor, by mounting the drive train unit with the PDU (Power Drive Unit) on the wheel side by applying reduction gears, it enables the reduction of maximum motor torque requirement. It also enables other parts of the drive system to be integrated into one unit. In this motor, IPM (Interior Permanent Magnet) structure has been implemented to cope with the high rotation of the motor, and the concentrated winding stator coil has been implemented for downsizing. As for the rotor, the magnets were placed in sections and the yoke shapes were improved to achieve higher rotation speeds that provide the higher power. The motor performances with the maximum power of 2.8 kW, the maximum torque of 11 Nm, the practical efficiency of 75% or more, and the maximum motor speed of 9000 r/min or more, have been achieved, which have satisfied the maximum specifications required from the drive train unit of the motorcycle.