Model: Y07 Three-Pulley Reversing Belt Transmission with Planetary Gear Train
This model is a compound mechanism consisting of a belt drive transmission and a planetary-ring gear train. Belt drive mechanisms can be seen in models in the V-series and planetary gear sets in models in the G-series. In this model, the ring gear is inside the inner belt pulley. The crank is directly coupled to the outside pulley as well as to the small ‘sun’ gear on the planetary gear set. The planet gear rotates about a separate fixed shaft that reverses the motion of the ring gear. A belt shaft slide similar to Model V-16 is used to move the belt. As one turns the crank with, say, the belt on the outside pulley, one can first shift the belt to the neutral wheel and then to the inner belt wheel that is also the outside of the ring gear that rotates in a direction opposite to the motion of the crank.

Francis Moon 2004-07-00