Patent ID: 6152249
Filing Date: 2000-11-28
Classification: B62M

Abstract:
A centrally-arranged co-axial electric power-assisted bicycle, comprising:a V-shaped frame having a vertical post with an upper end and a lower end and an inclined post with an upper end and a lower end, wherein said lower ends are connected at a connection point to form said V-shaped frame;a manual-driving device having a central shaft rotatable about an axis of rotation;a flat motor comprising a hollow central shaft, wherein said central shaft of said manual-driving device is inserted through said hollow central shaft and said hollow central shaft is rotatable about said axis of rotation, said motor comprising a flat disc-shaped rotor which is substantially perpendicular to said axis of rotation such that a magnetic field of said motor is substantially parallel with the direction of said axis of rotation;a battery mounted on said frame operatively connected for supplying electric power to said motor;a cup-shaped flexspline harmonic reducer operatively arranged for rotation about said axis of rotation, said cup-shaped flexspline harmonic reducer comprising a wave generator connected for rotation with said hollow central shaft, a power output device, and an exterior cover;a rear-power transmitting device arranged for rotation about said axis of rotation and coupled with said power-output device of said harmonic reducer; anda shell in which said motor, said harmonic reducer, and said bearing are arranged, wherein a center of weight of each rotational element of said motor, said harmonic reducer, and said rear-power transmitting device is on said axis of rotation.