Patent ID: 8636095
Filing Date: 2014-01-28
Classification: B60L,B62M,Y02T

Abstract:
1. An electric power-assisted bicycle comprising: a drive wheel including a hub and an axle; a transmission mechanism; a speed reduction mechanism; a driving motor; and a transmission control mechanism, wherein the transmission mechanism, the speed reduction mechanism, and the driving motor are placed in juxtaposition with each other in an axial direction of the axle in the hub of the drive wheel, wherein the transmission mechanism is arranged to transmit driving force from pedals to the drive wheel through a sprocket, the speed reduction mechanism is arranged to transmit driving force from the driving motor to the drive wheel, the transmission mechanism is constituted by a first planetary gear mechanism comprising at least one first sun gear, a first set of planetary gears meshed with the first sun gear, and a planetary carrier supporting the first set of planetary gears, the transmission control mechanism performs gear shifting such that the first sun gear is switched over in a rotatable and non-rotatable manner around the axle with respect to the driving force from the sprocket, the speed reduction mechanism is constituted by a second planetary gear mechanism comprising at least one second sun gear, a second set of and planetary gears meshed with the second sun gear, wherein the second set of planetary gears are supported by the planetary carrier or a member that is rotated integrally with the planetary carrier.