Planetary disc turns counter clockwise eccentrically driven by the eccentric cam.
External rollers turn counter clockwise accompany with planetary disc.
While external rollers turning counter clockwise accompany with planetary disc, the external rollers of the disc engages progressively with the internal rollers of the ring gear housing.
Cause the internal/external rollers can turn freely around their center, we call Such a transmission mode "Arroundable Tooth From" transmission.
Output shaft pins moving with planetary disc will turn counter clockwise; output shaft connected with output shaft pins also turns counter clockwise.
As figure A to D, input shaft truns for one cycle, external rollers turn for one tooth in reverse direction. As a result, the number of teeth of external rollers is equal to the reduction ratio.
