Patent ID: 6554730
Filing Date: 2003-04-29
Classification: B62M

Abstract:
A bicycle having wheels, a pair of pedals for driving the wheels, a pair of cranks connected to the pedals, and a reduction gear apparatus comprising:a pedal shaft connected to the pair of cranks to be rotatingly driven through the pair of pedals by an outer force, a battery for providing electric power, an electric motor adapted to be driven by the electric power from the battery and having a rotatable shaft for power output, said rotatable shaft having an outer peripheral surface, and a traction roller reduction gear comprising: an output shaft having an outer peripheral surface, a housing having a support shaft fixed thereto, said rotatable shaft being rotatably supported by the housing around a first rotation center, an outer ring rotatingly having a rolling inner peripheral surface portion, connected to the output shaft, and supported by the housing around a second rotation center, such that the second rotation center is eccentric with respect to the first rotation center, a wedging roller having a rolling outer peripheral surface portion, provided in a space between the rotatable shaft and the outer ring, the wedging roller being movable around the rotatable shaft toward a narrow portion in the space between the rotatable shaft and the outer ring until the rolling outer peripheral surface portion of the wedging roller comes into contact with the outer peripheral surface of the rotatable shaft and with the rolling inner peripheral surface portion of the outer ring, and a guide roller having a rolling outer peripheral surface portion, provided in contact with the outer peripheral surface of the rotatable shaft and the rolling inner peripheral surface portion of the outer ring, and rotatably supported by the support shaft fixed to the housing, wherein the pedal shaft is capable of driving the outer ring.