Ntn Corporation

Kiyohiro Ito

Eiji Maeno

A center motor power-assisted bicycle includes an internal transmission and has a regenerative function. A transmission comprises, in a drive wheel hub, a planetary gear, a one-way clutch for reverse input, a clutch switching device, and, a sun gear and transmits driving force from a sprocket to the drive wheel. A transmission control mechanism selectively rotationally fixes the sun gear to the axle to change speed when driving force is applied. The clutch is disposed between the sun gear and the axle, and selectively rotationally fixes the sun gear to the axle by the operation of the clutch switching device when reverse input is applied. While the bicycle is driven, the clutch switching device moves the clutch to the rotatable state, to transmit driving force. While the bicycle is traveling without being driven, the clutch is locked, so that reverse input is transmitted to the sprocket.

Power assisted bicycle with regenerative function

An electric power-assisted bicycle includes a transmission mechanism (), a speed reduction mechanism () and a drive motor () which are arranged in parallel in the direction of the an axle, inside a rear hub () of a drive wheel. The transmission mechanism () and the speed reduction mechanism () are each formed by planetary gear mechanisms, and a planetary carrier () is shared between the transmission mechanism and the speed reduction mechanism.

Growing community of inventors

Iwata, Japan

Kiyohiro Ito