When the axes of the first gear (i.e. first driver) and the last gear (i.e. last driven or follower) are co-axial, then the gear train is known as reverted gear train as shown in Fig. Thus we see that in a reverted gear train, the motion of the first gear and the last gear is like. ...

What gear reverses the direction of a gear train?

The idler reverses the direction of motion coming from the drive gear. This allows the driven gear to be turned in the same direction as the drive gear.

What is compound gear train?

A compound gear is a number of gears fixed together. Consequently, they rotate at the same speed. ... The gear train below has an arrangement of gear wheels including two compound gears. Gear trains like this are often found inside machines such as centre lathes and milling machines.