System for the electrical propulsion of light-weight wheeled transportation vehicles

摘要

An electrical propulsion system for bicycles (E-bike) is claimed. The system comprises an electric motor, at least three speed reduction stages and an output gear (driven gear). The motor has an output shaft oriented towards one side of the system, while the output gear is located on the opposite side of the system. The first and second reduction stage are located on the same side as the drive gear which is mounted on the output shaft of the motor. The sub-claims specify the first reduction stage to be a planetary gear set and specify the location of the third reduction stage. Further is the motor defined as high speed motor and is the system specified as module for mounting to a bicycle bottom bracket.